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Sample records for sympathetic nerve imaging

  1. Renal sympathetic nerve ablation for treatment-resistant hypertension

    Science.gov (United States)

    Krum, Henry; Schlaich, Markus; Sobotka, Paul

    2013-01-01

    Hypertension is a major risk factor for increased cardiovascular events with accelerated sympathetic nerve activity implicated in the pathogenesis and progression of disease. Blood pressure is not adequately controlled in many patients, despite the availability of effective pharmacotherapy. Novel procedure- as well as device-based strategies, such as percutaneous renal sympathetic nerve denervation, have been developed to improve blood pressure in these refractory patients. Renal sympathetic denervation not only reduces blood pressure but also renal as well as systemic sympathetic nerve activity in such patients. The reduction in blood pressure appears to be sustained over 3 years after the procedure, which suggests absence of re-innervation of renal sympathetic nerves. Safety appears to be adequate. This approach may also have potential in other disorders associated with enhanced sympathetic nerve activity such as congestive heart failure, chronic kidney disease and metabolic syndrome. This review will focus on the current status of percutaneous renal sympathetic nerve denervation, clinical efficacy and safety outcomes and prospects beyond refractory hypertension. PMID:23819768

  2. Sympathetic vasoconstrictor nerve function in alcoholic neuropathy

    DEFF Research Database (Denmark)

    Jensen, K; Andersen, K; Smith, T

    1984-01-01

    (18% and 48% decrease respectively). However, in three patients with moderate neuropathy, and in one patient with no signs of neuropathy, this veno-arteriolar reflex was absent, indicating dysfunction of the peripheral sympathetic adrenergic nerve fibres. The three patients also showed a lesser degree......The peripheral sympathetic vasomotor nerve function was investigated in 18 male chronic alcoholics admitted for intellectual impairment or polyneuropathy. By means of the local 133Xenon washout technique, the sympathetic veno-arteriolar axon-reflex was studied. This normally is responsible for a 50...... comprise not only the peripheral sensory and motor nerve fibres, but also the thin pseudomotor and vasomotor nerves....

  3. Autonomic markers of emotional processing: skin sympathetic nerve activity in humans during exposure to emotionally charged images.

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    Brown, Rachael; James, Cheree; Henderson, Luke A; Macefield, Vaughan G

    2012-01-01

    The sympathetic innervation of the skin primarily subserves thermoregulation, but the system has also been commandeered as a means of expressing emotion. While it is known that the level of skin sympathetic nerve activity (SSNA) is affected by anxiety, the majority of emotional studies have utilized the galvanic skin response as a means of inferring increases in SSNA. The purpose of the present study was to characterize the changes in SSNA when showing subjects neutral or emotionally charged images from the International Affective Picture System (IAPS). SSNA was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in ten subjects. Neutral images, positively charged images (erotica) or negatively charged images (mutilation) were presented in blocks of fifteen images of a specific type, each block lasting 2 min. Images of erotica or mutilation were presented in a quasi-random fashion, each block following a block of neutral images. Both images of erotica or images of mutilation caused significant increases in SSNA, but the increases in SSNA were greater for mutilation. The increases in SSNA were often coupled with sweat release and cutaneous vasoconstriction; however, these markers were not always consistent with the SSNA increases. We conclude that SSNA, comprising cutaneous vasoconstrictor and sudomotor activity, increases with both positively charged and negatively charged emotional images. Measurement of SSNA provides a more comprehensive assessment of sympathetic outflow to the skin than does the use of sweat release alone as a marker of emotional processing.

  4. Sympathetic Nerve Injury in Thyroid Cancer

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    Evangelos Diamantis

    2018-04-01

    Full Text Available The double innervation of the thyroid comes from the sympathetic and parasympathetic nervous system. Injury rates during surgery are at 30% but can be minimized by upwardly preparing the thyroid vessels at the level of thyroid capsule. Several factors have been accused of increasing the risk of injury including age and tumor size. Our aim was to investigate of there is indeed any possible correlations between these factors and a possible increase in injury rates following thyroidectomy. Seven studies were included in the meta-analysis. Statistical correlation was observed for a positive relationship between injury of the sympathetic nerve and thyroid malignancy surgery (p < 0.001; I2 = 74% No statistical correlations were observed for a negative or positive relationship between injury of the sympathetic nerve and tumor size. There was also no statistically significant value observed for the correlation of the patients’ age with the risk of sympathetic nerve injury (p = 0.388. Lack of significant correlation reported could be due to the small number of studies and great heterogeneity between them.

  5. Alterations of sympathetic nerve fibers in avascular necrosis of femoral head.

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    Li, Deqiang; Liu, Peilai; Zhang, Yuankai; Li, Ming

    2015-01-01

    Avascular necrosis of the femoral head (ANFH) was mainly due to alterations of bone vascularity. And noradrenaline (NA), as the neurotransmitter of the sympathetic nervous system (SNS), leads to the vasoconstriction by activating its α-Receptor. This study was to explore the nerve fiber density of the femoral head in the rabbit model of ANFH. Twenty New Zealand white rabbits were used in this study. The rabbit model of ANFH was established by the injection of methylprednisolone acetate. The nerve fiber density and distribution in the femoral head was determined using an Olympus BH2 microscope. Significant fewer sympathetic nerve fibers was found in the ANFH intertrochanteric bone samples (P = 0.036) with osteonecrosis. The number of sympathetic nerve fibers was compared between the two groups. And less sympathetic nerve fibers were found in later stage ANFH samples in comparison with those of early stages. ANFH might be preceded by an inflammatory reaction, and an inflammatory response might lead to arthritic changes in tissue samples, which in turn reduces the number of sympathetic nerve fibers.

  6. Sympathetic nerves: How do they affect angiogenesis, particularly during wound healing of soft tissues?

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    Pan, Liangli; Tang, Jianbing; Liu, Hongwei; Cheng, Biao

    2016-01-01

    Angiogenesis is essential for wound healing, and angiogenesis impairment can result in chronic ulcers. Studies have shown that the sympathetic nervous system has an important role in angiogenesis. In recent years, researchers have focused on the roles of sympathetic nerves in tumor angiogenesis. In fact, sympathetic nerves can affect angiogenesis in the wound healing of soft tissues, and may have a similar mechanism of action as that seen in tumorigenesis. Sympathetic nerves act primarily through interactions between the neurotransmitters released from nerve endings and receptors present in target organs. Among this, activation or inhibition of adrenergic receptors (mainly β-adrenergic receptors) influence formation of new blood vessels considerably. As sympathetic nerves locate near pericytes in microvessel, go along the capillaries and there are adrenergic receptors present in endothelial cells and pericytes, sympathetic nerves may participate in angiogenesis by influencing the endothelial cells and pericytes of new capillaries. Studying the roles of sympathetic nerves on the angiogenesis of wound healing can contribute to understanding the mechanisms of tissue repair, tissue regeneration, and tumorigenesis, thereby providing new therapeutic perspectives.

  7. RESISTIN, AN ADIPOKINE WITH NON-GENERALISED ACTIONS ON SYMPATHETIC NERVE ACTIVITY

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    Emilio eBadoer

    2015-11-01

    Full Text Available The World Health Organisation has called obesity a global epidemic. There is a strong association between body weight gain and blood pressure. A major determinant of blood pressure is the level of activity in sympathetic nerves innervating cardiovascular organs. A characteristic of obesity, in both humans and in animal models, is an increase in sympathetic nerve activity to the skeletal muscle vasculature and to the kidneys. Obesity is now recognised as a chronic, low level inflammatory condition and pro-inflammatory cytokines are elevated including those produced by adipose tissue. The most well known adipokine released from fat tissue is leptin. The adipokine, resistin,, is also released from adipose tissue. Resistin can act in the central nervous system to influence the sympathetic nerve activity. Here, we review the effects of resistin on sympathetic nerve activity and compare them with leptin. We build an argument that resistin and leptin may have complex interactions. Firstly, they may augment each other as both are excitatory on sympathetic nerves innervating cardiovascular organs; In contrast, they could antagonize each other’s actions on brown adipose tissue, a key metabolic organ. These interactions may be important in conditions in which leptin and resistin are elevated, such as in obesity.

  8. The synthesis of a new cardiac sympathetic nerve imaging agent N-[11C]CH3-dopamine and biodistribution study

    International Nuclear Information System (INIS)

    Yulin He; Weina Zhou; Xiangcheng Wang; Baoliang Bao; Guojian Zhang; Cheng Wang; Chunmei Wang; Xuemei Wang; Wei Fang

    2014-01-01

    In this study, we synthesized and characterized N-[ 11 C]methyl-dopamine ([ 11 C]MDA) for cardiac sympathetic nerve imaging. [ 11 C]MDA was synthesized by direct N-methylation of dopamine with [ 11 C]methyl iodide and purified by semi-preparation reverse high pressure liquid chromatography (HPLC). The total synthesis time was 45 min including HPLC purification. The radiochemical yields of [ 11 C]MDA was 20 ± 3 %, without decay correction. The radiochemical purity was >98 % and the specific activity was about 50 GBq/mmol. The biological properties of [ 11 C]MDA were evaluated by biodistribution study in normal mice. PET imaging was performed in healthy Chinese mini-swines. Biodistribution study showed that [ 11 C]MDA had high myocardium uptake. PET/CT imaging showed [ 11 C]MDA had clear and symmetrical myocardium uptake, which was blocked obviously by injecting imipramine hydrochloride. [ 11 C]MDA would be a promising candidate of radiotracer for cardiac sympathetic nervous system imaging. (author)

  9. Assessment of central chemosensitivity and cardiac sympathetic nerve activity using I-123 MIBG imaging in central sleep apnea syndrome in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Meguro, Kentaro; Nagai, Ryozo; Toyama, Takuji; Adachi, Hitoshi; Ohshima, Shigeru; Taniguchi, Koichi

    2007-01-01

    Iodine-123 m-iodobenzylguanidine (MIBG) imaging has been used to study cardiac sympathetic function in various cardiac diseases. Central sleep apnea syndrome (CSAS) occurs frequently in patients with chronic heart failure (CHF) and is reported to be associated with a poor prognosis. One of the mechanisms of its poor prognosis may be related to impaired cardiac sympathetic activity. However, the relationship between chemosensitivity to carbon dioxide, which is reported to correlate with the severity of CSAS, and cardiac sympathetic activity has not been investigated. Therefore, this study was undertaken to assess cardiac sympathetic function and chemosensitivity to carbon dioxide in CHF patients. The oxygen desaturation index (ODI) was evaluated in 21 patients with dilated cardiomyopathy (male/female: 19/2, left ventricular ejection fraction (LVEF) 5 times/h underwent polysomnography. Patients with an apnea hypopnea index >15/h but without evidence of obstructive apnea were defined as having CSAS. Early (15 min) and delayed (4 hr) planar MIBG images were obtained from these patients. The mean counts in the whole heart and the mediastinum were obtained. The heart-to-mediastinum count ratio of the delayed image (H/M) and the corrected myocardial washout rate (WR) were also calculated. The central chemoreflex was assessed with the rebreathing method using a hypercapnic gas mixture (7% CO 2 and 93% O 2 ). Ten of the 21 patients had CSAS. The H/M ratio was similar in patients both with and without CSAS (1.57±0.18 vs. 1.59±0.14, p=0.82). However, the WR was higher in patients with CSAS than in patients without CSAS (40±8% vs. 30±12%, p<0.05). ODI significantly correlated with central chemosensitivity to carbon dioxide. Moreover, there was a highly significant correlation between WR and central chemosensitivity (r=0.65, p<0.05). However, there was no correlation between ODI and the WR (r=0.36, p=0.11). Cardiac sympathetic nerve activity in patients with CHF and CSAS is

  10. Loss of Sympathetic Nerves in Spleens from Patients with End Stage Sepsis

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    Donald B. Hoover

    2017-12-01

    Full Text Available The spleen is an important site for central regulation of immune function by noradrenergic sympathetic nerves, but little is known about this major region of neuroimmune communication in humans. Experimental studies using animal models have established that sympathetic innervation of the spleen is essential for cholinergic anti-inflammatory responses evoked by vagal nerve stimulation, and clinical studies are evaluating this approach for treating inflammatory diseases. Most data on sympathetic nerves in spleen derive from rodent studies, and this work has established that remodeling of sympathetic innervation can occur during inflammation. However, little is known about the effects of sepsis on spleen innervation. Our primary goals were to (i localize noradrenergic nerves in human spleen by immunohistochemistry for tyrosine hydroxylase (TH, a specific noradrenergic marker, (ii determine if nerves occur in close apposition to leukocytes, and (iii determine if splenic sympathetic innervation is altered in patients who died from end stage sepsis. Staining for vesicular acetylcholine transporter (VAChT was done to screen for cholinergic nerves. Archived paraffin tissue blocks were used. Control samples were obtained from trauma patients or patients who died after hemorrhagic stroke. TH + nerves were associated with arteries and arterioles in all control spleens, occurring in bundles or as nerve fibers. Individual TH + nerve fibers entered the perivascular region where some appeared in close apposition to leukocytes. In marked contrast, spleens from half of the septic patients lacked TH + nerves fibers and the average abundance of TH + nerves for the septic group was only 16% of that for the control group (control: 0.272 ± 0.060% area, n = 6; sepsis: 0.043 ± 0.026% area, n = 8; P < 0.005. All spleens lacked cholinergic innervation. Our results provide definitive evidence for the distribution of noradrenergic

  11. Sympathetic nerve-derived ATP regulates renal medullary blood flow via vasa recta pericytes

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    Scott S Wildman

    2013-10-01

    Full Text Available Pericyte cells are now known to be a novel locus of blood flow control, being able to regulate capillary diameter via their unique morphology and expression of contractile proteins. We have previously shown that exogenous ATP causes constriction of vasa recta via renal pericytes, acting at a variety of membrane bound P2 receptors on descending vasa recta, and therefore may be able to regulate medullary blood flow (MBF. Regulation of MBF is essential for appropriate urine concentration and providing essential oxygen and nutrients to this region of high, and variable, metabolic demand. Various sources of endogenous ATP have been proposed, including from epithelial, endothelial and red blood cells in response to stimuli such as mechanical stimulation, local acidosis, hypoxia, and exposure to various hormones. Extensive sympathetic innervation of the nephron has previously been shown, however the innervation reported has focused around the proximal and distal tubules, and ascending loop of Henle. We hypothesise that sympathetic nerves are an additional source of ATP acting at renal pericytes and therefore regulate MBF. Using a rat live kidney slice model in combination with video imaging and confocal microscopy techniques we firstly show sympathetic nerves in close proximity to vasa recta pericytes in both the outer and inner medulla. Secondly, we demonstrate pharmacological stimulation of sympathetic nerves in situ (by tyramine evokes pericyte-mediated vasoconstriction of vasa recta capillaries; inhibited by the application of the P2 receptor antagonist suramin. Lastly, tyramine-evoked vasoconstriction of vasa recta by pericytes is significantly less than ATP-evoked vasoconstriction. Sympathetic innervation may provide an additional level of functional regulation in the renal medulla that is highly localized. It now needs to be determined under which physiological/pathophysiological circumstances that sympathetic innervation of renal pericytes is

  12. Anatomic assessment of sympathetic peri-arterial renal nerves in man.

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    Sakakura, Kenichi; Ladich, Elena; Cheng, Qi; Otsuka, Fumiyuki; Yahagi, Kazuyuki; Fowler, David R; Kolodgie, Frank D; Virmani, Renu; Joner, Michael

    2014-08-19

    Although renal sympathetic denervation therapy has shown promising results in patients with resistant hypertension, the human anatomy of peri-arterial renal nerves is poorly understood. The aim of our study was to investigate the anatomic distribution of peri-arterial sympathetic nerves around human renal arteries. Bilateral renal arteries were collected from human autopsy subjects, and peri-arterial renal nerve anatomy was examined by using morphometric software. The ratio of afferent to efferent nerve fibers was investigated by dual immunofluorescence staining using antibodies targeted for anti-tyrosine hydroxylase and anti-calcitonin gene-related peptide. A total of 10,329 nerves were identified from 20 (12 hypertensive and 8 nonhypertensive) patients. The mean individual number of nerves in the proximal and middle segments was similar (39.6 ± 16.7 per section and 39.9 ± 1 3.9 per section), whereas the distal segment showed fewer nerves (33.6 ± 13.1 per section) (p = 0.01). Mean subject-specific nerve distance to arterial lumen was greatest in proximal segments (3.40 ± 0.78 mm), followed by middle segments (3.10 ± 0.69 mm), and least in distal segments (2.60 ± 0.77 mm) (p renal sympathetic nerve fibers is lower in distal segments and dorsal locations. There is a clear predominance of efferent nerve fibers, with decreasing prevalence of afferent nerves from proximal to distal peri-arterial and renal parenchyma. Understanding these anatomic patterns is important for refinement of renal denervation procedures. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  13. Effect of sympathetic nerve block on acute inflammatory pain and hyperalgesia

    DEFF Research Database (Denmark)

    Pedersen, J L; Rung, G W; Kehlet, H

    1997-01-01

    BACKGROUND: Sympathetic nerve blocks relieve pain in certain chronic pain states, but the role of the sympathetic pathways in acute pain is unclear. Thus the authors wanted to determine whether a sympathetic block could reduce acute pain and hyperalgesia after a heat injury in healthy volunteers....... The duration and quality of blocks were evaluated by the sympatogalvanic skin response and skin temperature. Bilateral heat injuries were produced on the medial surfaces of the calves with a 50 x 25 mm thermode (47 degrees C, 7 min) 45 min after the blocks. Pain intensity induced by heat, pain thresholds...... between sympathetic block and placebo for pain or mechanical allodynia during injury, or pain thresholds, pain responses to heat, or areas of secondary hyperalgesia after the injury. The comparisons were done for the period when the block was effective. CONCLUSION: Sympathetic nerve block did not change...

  14. Evaluation of myocardial sympathetic nerve function in patients with mitral valve prolapse using iodine-123-metaiodobenzylguanidine myocardial scintigraphy

    International Nuclear Information System (INIS)

    Kishi, Fumiko; Nomura, Masahiro; Yukinaka, Michiko

    1996-01-01

    Mitral valve prolapse (MVP) is closely related to myocardial sympathetic nerve function. This study evaluated the presence of impaired myocardial sympathetic nerve function by Iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy in nine patients with MVP. For comparison, 15 healthy subjects without heart disease were investigated (control group). Single photon emission computed tomography (SPECT) and anterior planar myocardial scintigraphy were performed 15 min (initial images) and 3 hours (delayed images) after injection of MIBG (111 MBq). The location and degrees of reduced tracer uptake were evaluated. Myocardial MIBG uptake was quantified by uptake ratio of the heart (H) to upper mediastinum (M) on the anterior planar images (H/M). Percentage washout of MIBG in nine sectors of all oblique slices along the short-axis was calculated. The washout rates were higher at the inferoposterior and septal segments in patients with anterior leaflet prolapse, and at inferoposterior and lateral segments in patients with posterior leaflet prolapse. The bull's eye map showed increased washout rate in the apical and posteroseptal basal segments. There was no significant difference in the H/M ratio between MVP patients and the control group. These results indicate that MIBG can be used to evaluate localized myocardial sympathetic nerve function in MVP. (author)

  15. Clinical usefulness of 123I-metaiodobenzylguanidine myocardial scintigraphy in diabetic patients with cardiac sympathetic nerve dysfunction

    International Nuclear Information System (INIS)

    Miyanaga, Hajime; Yoneyama, Satoshi; Kamitani, Tadaaki; Kawasaki, Shingo; Takahashi, Toru; Kunishige, Hiroshi

    1995-01-01

    To assess the clinical utility of 123 I-metaiodobenzylguanidine (MIBG) scintigraphy in evaluating cardiac sympathetic nerve disturbance in diabetic patients, we performed MIBG scintigraphy in 18 diabetic patients and 11 normal controls. Diabetic patients with symptomatic neuropathy (DM2) had a significantly lower heart to mediastinum uptake ratio than did those without neuropathy or normal controls in initial and delayed images (initial image, 1.90±0.27 vs 2.32±0.38, 2.41±0.40, p<0.01; delayed image, 1.80±0.31 vs 2.48±0.35, 2.56±0.28, p<001, respectively). Defect score, assessed visually, were higher in DM2 patients than in patients in the other two groups (initial image, 7±2.6 vs 1.5±1.9, 0.7±0.9; delayed image 10.6±3.3 vs 4.0±2.5, 1.7±1.6 p<0.01, respectively). The maximum washout rate in DM2 patients was also higher than those in patients in the other two groups. The findings of these indices obtained from MIBG scintigraphy coincided with the % low-frequency power extracted from heart rate fluctuations using a power spectral analysis and the results of the Schellong test, which were used to evaluate sympathetic function. These results suggest that MIBG scintigraphy may be useful for evaluating cardiac sympathetic nerve disturbance in patients with diabetes. (author)

  16. Pet measurements of presynaptic sympathetic nerve terminals in the heart

    International Nuclear Information System (INIS)

    Schwaiger, M.; Hutchins, G.D.; Wieland, D.M.

    1991-01-01

    [ 18 F]Metaraminol (FMR) and [ 11 C]hydroxyephedrine (HED) are catecholamine analogues that have been developed at the University of Michigan for the noninvasive characterization of the sympathetic nervous system of the heart using positron emission tomography (PET). Pharmacological studies employing neurotoxins and uptake inhibitors have demonstrated that both FMR and HED specifically trace the uptake and storage of catecholamines in sympathetic nerve terminals with little nonspecific tracer accumulation. These compounds exhibit excellent qualitative imaging characteristics with heart-to-blood ratios exceeding 6:1 as early as 15 min after intravenous injection in both animals (HED and FMR) and humans (HED). Tracer kinetic modeling techniques have been employed for the quantitative assessment of neuronal catecholamine uptake and storage. Indices of neuronal function, such as the volume of tracer distribution derived from the kinetic models, have been employed in preliminary human studies. Comparison of the tissue distribution volume of HED between normal (control subjects) and denervated (recent transplant patients) cardiac tissue demonstrates a dynamic range of approximately 5:1. This distribution volume is reduced by 60% from normal in patients with dilated cardiomyopathy, indicating dysfunction of the sympathetic system. These results show that HED used in combination with PET provides a sophisticated quantitative approach for studying the sympathetic nervous system of the normal and diseased human heart

  17. Electroacupuncture Improved the Function of Myocardial Ischemia Involved in the Hippocampus-Paraventricular Nucleus-Sympathetic Nerve Pathway

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    Shuai Cui

    2018-01-01

    Full Text Available We investigated the hippocampus-paraventricular nucleus- (PVN- sympathetic nerve pathway in electroacupuncture (EA at the heart meridian for the treatment of myocardial ischemia by observing PVN neuronal discharge, sympathetic nerve discharge, and hemodynamics parameters. Sprague Dawley (SD rats were equally divided into four groups: Sham, Model, Model + EA, and Model + EA + Lesion. The model rat was established by ligating the left anterior descending branch of the coronary artery. Changes in the sympathetic nerve discharge and hemodynamic parameters were observed. The Model + EA exhibited a significantly lower discharge frequency of PVN neurons compared with the Model. The Model + EA + Lesion had a significantly higher discharge frequency compared with the Model + EA. The total discharge frequency of PVN neurons and interneurons were positively correlated with the sympathetic nerve discharge. The total discharge frequency of PVN neurons was positively correlated with heart rate (HR and negatively correlated with mean arterial pressure (MAP and rate pressure product (RPP. The discharge frequency of interneurons was positively correlated with HR and negatively correlated with MAP and RPP. The hippocampus-PVN-sympathetic nerve pathway is involved in electroacupuncture at the heart meridian and interneurons are the key neurons in PVNs.

  18. Renal sympathetic nerve, blood flow, and epithelial transport responses to thermal stress.

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    Wilson, Thad E

    2017-05-01

    Thermal stress is a profound sympathetic stress in humans; kidney responses involve altered renal sympathetic nerve activity (RSNA), renal blood flow, and renal epithelial transport. During mild cold stress, RSNA spectral power but not total activity is altered, renal blood flow is maintained or decreased, and epithelial transport is altered consistent with a sympathetic stress coupled with central volume loaded state. Hypothermia decreases RSNA, renal blood flow, and epithelial transport. During mild heat stress, RSNA is increased, renal blood flow is decreased, and epithelial transport is increased consistent with a sympathetic stress coupled with a central volume unloaded state. Hyperthermia extends these directional changes, until heat illness results. Because kidney responses are very difficult to study in humans in vivo, this review describes and qualitatively evaluates an in vivo human skin model of sympathetically regulated epithelial tissue compared to that of the nephron. This model utilizes skin responses to thermal stress, involving 1) increased skin sympathetic nerve activity (SSNA), decreased skin blood flow, and suppressed eccrine epithelial transport during cold stress; and 2) increased SSNA, skin blood flow, and eccrine epithelial transport during heat stress. This model appears to mimic aspects of the renal responses. Investigations of skin responses, which parallel certain renal responses, may aid understanding of epithelial-sympathetic nervous system interactions during cold and heat stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Does transcutaneous nerve stimulation have effect on sympathetic skin response?

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    Okuyucu, E Esra; Turhanoğlu, Ayşe Dicle; Guntel, Murat; Yılmazer, Serkan; Savaş, Nazan; Mansuroğlu, Ayhan

    2018-01-01

    This study examined the effects of transcutaneous electrical nerve stimulation (TENS) on the sympathetic nerve system by sympathetic skin response test. Fifty-five healthy volunteers received either: (i) 30minutes TENS (25 participants) (ii) 30minutes sham TENS (30 participants) and SSR test was performed pre- and post-TENS. The mean values of latency and peak-to-peak amplitude of five consecutive SSRs were calculated. A significant amplitude difference was found between TENS and sham TENS group both in right and left hand (p=0.04, p=0.01, respectively). However there was no significant latancy difference between two groups (p>0.05 ). TENS has an inhibitory effect on elicited SNS responses when compared with sham TENS control group. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Myocardial Infarction Causes Transient Cholinergic Transdifferentiation of Cardiac Sympathetic Nerves via gp130.

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    Olivas, Antoinette; Gardner, Ryan T; Wang, Lianguo; Ripplinger, Crystal M; Woodward, William R; Habecker, Beth A

    2016-01-13

    Sympathetic and parasympathetic control of the heart is a classic example of norepinephrine (NE) and acetylcholine (ACh) triggering opposing actions. Sympathetic NE increases heart rate and contractility through activation of β receptors, whereas parasympathetic ACh slows the heart through muscarinic receptors. Sympathetic neurons can undergo a developmental transition from production of NE to ACh and we provide evidence that mouse cardiac sympathetic nerves transiently produce ACh after myocardial infarction (MI). ACh levels increased in viable heart tissue 10-14 d after MI, returning to control levels at 21 d, whereas NE levels were stable. At the same time, the genes required for ACh synthesis increased in stellate ganglia, which contain most of the sympathetic neurons projecting to the heart. Immunohistochemistry 14 d after MI revealed choline acetyltransferase (ChAT) in stellate sympathetic neurons and vesicular ACh transporter immunoreactivity in tyrosine hydroxylase-positive cardiac sympathetic fibers. Finally, selective deletion of the ChAT gene from adult sympathetic neurons prevented the infarction-induced increase in cardiac ACh. Deletion of the gp130 cytokine receptor from sympathetic neurons prevented the induction of cholinergic genes after MI, suggesting that inflammatory cytokines induce the transient acquisition of a cholinergic phenotype in cardiac sympathetic neurons. Ex vivo experiments examining the effect of NE and ACh on rabbit cardiac action potential duration revealed that ACh blunted both the NE-stimulated decrease in cardiac action potential duration and increase in myocyte calcium transients. This raises the possibility that sympathetic co-release of ACh and NE may impair adaptation to high heart rates and increase arrhythmia susceptibility. Sympathetic neurons normally make norepinephrine (NE), which increases heart rate and the contractility of cardiac myocytes. We found that, after myocardial infarction, the sympathetic neurons

  1. Renal hemodynamic effects of activation of specific renal sympathetic nerve fiber groups.

    Science.gov (United States)

    DiBona, G F; Sawin, L L

    1999-02-01

    To examine the effect of activation of a unique population of renal sympathetic nerve fibers on renal blood flow (RBF) dynamics, anesthetized rats were instrumented with a renal sympathetic nerve activity (RSNA) recording electrode and an electromagnetic flow probe on the ipsilateral renal artery. Peripheral thermal receptor stimulation (external heat) was used to activate a unique population of renal sympathetic nerve fibers and to increase total RSNA. Total RSNA was reflexly increased to the same degree with somatic receptor stimulation (tail compression). Arterial pressure and heart rate were increased by both stimuli. Total RSNA was increased to the same degree by both stimuli but external heat produced a greater renal vasoconstrictor response than tail compression. Whereas both stimuli increased spectral density power of RSNA at both cardiac and respiratory frequencies, modulation of RBF variability by fluctuations of RSNA was small at these frequencies, with values for the normalized transfer gain being approximately 0.1 at >0.5 Hz. During tail compression coherent oscillations of RSNA and RBF were found at 0.3-0.4 Hz with normalized transfer gain of 0.33 +/- 0.02. During external heat coherent oscillations of RSNA and RBF were found at both 0.2 and 0.3-0.4 Hz with normalized transfer gains of 0. 63 +/- 0.05 at 0.2 Hz and 0.53 +/- 0.04 to 0.36 +/- 0.02 at 0.3-0.4 Hz. Renal denervation eliminated the oscillations in RBF at both 0.2 and 0.3-0.4 Hz. These findings indicate that despite similar increases in total RSNA, external heat results in a greater renal vasoconstrictor response than tail compression due to the activation of a unique population of renal sympathetic nerve fibers with different frequency-response characteristics of the renal vasculature.

  2. Sympathetic nerve damage and restoration after ischemia-reperfusion injury as assessed by {sup 11}C-hydroxyephedrine

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    Werner, Rudolf A.; Higuchi, Takahiro [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); University of Wuerzburg, Comprehensive Heart Failure Center, Wuerzburg (Germany); Maya, Yoshifumi [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Nihon Medi-Physics Co., Ltd., Research Centre, Chiba (Japan); Rischpler, Christoph [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Muenchen (Germany); Javadi, Mehrbod S. [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology, Baltimore, MD (United States); Fukushima, Kazuhito [Hyogo College of Medicine, Department of Radiology, Hyogo (Japan); Lapa, Constantin [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Herrmann, Ken [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); David Geffen School of Medicine at UCLA, Department of Molecular and Medical Pharmacology, Los Angeles, CA (United States)

    2016-02-15

    An altered state of the cardiac sympathetic nerves is an important prognostic factor in patients with coronary artery disease. The aim of this study was to investigate regional sympathetic nerve damage and restoration utilizing a rat model of myocardial transient ischemia and a catecholamine analog PET tracer, {sup 11}C-hydroxyephedrine ({sup 11}C-HED). Transient myocardial ischemia was induced by coronary occlusion for 20 min and reperfusion in male Wistar rats. Dual-tracer autoradiography was performed subacutely (7 days) and chronically (2 months) after ischemia, and in control rats without ischemia using {sup 11}C-HED as a marker of sympathetic innervation and {sup 201}TI for perfusion. Additional serial in vivo cardiac {sup 11}C-HED and {sup 18}F-FDG PET scans were performed in the subacute and chronic phases after ischemia. After transient ischemia, the {sup 11}C-HED uptake defect areas in both the subacute and chronic phases were clearly larger than the perfusion defect areas in the midventricular wall. The subacute {sup 11}C-HED uptake defect showed a transmural pattern, whereas uptake recovered in the subepicardial portion in the chronic phase. Tyrosine hydroxylase antibody nerve staining confirmed regional denervation corresponding to areas of decreased {sup 11}C-HED uptake. Serial in vivo PET imaging visualized reductions in the area of the {sup 11}C-HED uptake defects in the chronic phase consistent with autoradiography and histology. Higher susceptibility of sympathetic neurons compared to myocytes was confirmed by a larger {sup 11}C-HED defect with a corresponding histologically identified region of denervation. Furthermore, partial reinnervation was observed in the chronic phase as shown by recovery of subepicardial {sup 11}C-HED uptake. (orig.)

  3. Study of nerve fibers nature reinforcing duodenal contractions by electrical stimulation of sympathetic nerve

    Directory of Open Access Journals (Sweden)

    Sveshnikov D.S.

    2011-09-01

    Full Text Available The subject of the article is to investigate the mechanism of increased reactions by electrical stimulation of the sympathetic nerve. Materials and methods: Experiments on dogs have shown that stimulant reactions during blockade of a-adrenergic by phentolamine and (3-adrenergic receptors with propranolol were completely eliminated by lizer-gol —the blocker of 5-HT12-receptors. Results: Infusion of lizergol did not influence on duodenal motor activity and the function of the vagus nerve. Conclusion: Effector neuron is found out to be serotonergic and its action is provided by 5-HT1 2 receptors

  4. Eppur Si Muove: The dynamic nature of physiological control of renal blood flow by the renal sympathetic nerves.

    Science.gov (United States)

    Schiller, Alicia M; Pellegrino, Peter Ricci; Zucker, Irving H

    2017-05-01

    Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Slow and deep respiration suppresses steady-state sympathetic nerve activity in patients with chronic heart failure: from modeling to clinical application.

    Science.gov (United States)

    Harada, Daisuke; Asanoi, Hidetsugu; Takagawa, Junya; Ishise, Hisanari; Ueno, Hiroshi; Oda, Yoshitaka; Goso, Yukiko; Joho, Shuji; Inoue, Hiroshi

    2014-10-15

    Influences of slow and deep respiration on steady-state sympathetic nerve activity remain controversial in humans and could vary depending on disease conditions and basal sympathetic nerve activity. To elucidate the respiratory modulation of steady-state sympathetic nerve activity, we modeled the dynamic nature of the relationship between lung inflation and muscle sympathetic nerve activity (MSNA) in 11 heart failure patients with exaggerated sympathetic outflow at rest. An autoregressive exogenous input model was utilized to simulate entire responses of MSNA to variable respiratory patterns. In another 18 patients, we determined the influence of increasing tidal volume and slowing respiratory frequency on MSNA; 10 patients underwent a 15-min device-guided slow respiration and the remaining 8 had no respiratory modification. The model predicted that a 1-liter, step increase of lung volume decreased MSNA dynamically; its nadir (-33 ± 22%) occurred at 2.4 s; and steady-state decrease (-15 ± 5%), at 6 s. Actually, in patients with the device-guided slow and deep respiration, respiratory frequency effectively fell from 16.4 ± 3.9 to 6.7 ± 2.8/min (P state MSNA was decreased by 31% (P state MSNA. Thus slow and deep respiration suppresses steady-state sympathetic nerve activity in patients with high levels of resting sympathetic tone as in heart failure. Copyright © 2014 the American Physiological Society.

  6. Effect of percutaneous renal sympathetic nerve radiofrequency ablation in patients with severe heart failure.

    Science.gov (United States)

    Dai, Qiming; Lu, Jing; Wang, Benwen; Ma, Genshan

    2015-01-01

    This study aimed to investigate the clinical feasibility and effects of percutaneous renal sympathetic nerve radiofrequency ablation in patients with heart failure. A total of 20 patients with heart failure were enrolled, aged from 47 to 75 years (63±10 years). They were divided into the standard therapy (n = 10), and renal nerve radiofrequency ablation groups (n = 10). There were 15 males and 5 female patients, including 8 ischemic cardiomyopathy, 8 dilated cardiomyopathy, and 8 hypertensive cardiopathy. All of the patients met the criteria of New York Heart Association classes III-IV cardiac function. Patients with diabetes and renal failure were excluded. Percutaneous renal sympathetic nerve radiofrequency ablation was performed on the renal artery wall under X-ray guidance. Serum electrolytes, neurohormones, and 24 h urine volume were recorded 24 h before and after the operation. Echocardiograms were performed to obtain left ventricular ejection fraction at baseline and 6 months. Heart rate, blood pressure, symptoms of dyspnea and edema were also monitored. After renal nerve ablation, 24 h urine volume was increased, while neurohormone levels were decreased compared with those of pre-operation and standard therapy. No obvious change in heart rate or blood pressure was recorded. Symptoms of heart failure were improved in patients after the operation. No complications were recorded in the study. Percutaneous renal sympathetic nerve radiofrequency ablation may be a feasible, safe, and effective treatment for the patients with severe congestive heart failure.

  7. Percutaneous renal sympathetic nerve ablation for loin pain haematuria syndrome.

    Science.gov (United States)

    Gambaro, Giovanni; Fulignati, Pierluigi; Spinelli, Alessio; Rovella, Valentina; Di Daniele, Nicola

    2013-09-01

    Loin pain haematuria syndrome (LPHS) is a severe renal pain condition of uncertain origin and often resistant to treatment. Nephrectomy and renal autotrasplantation have occasionally been performed in very severe cases. Its pathogenesis is controversial. A 40-year-old hypertensive lady was diagnosed with LPHS after repeated diagnostic imaging procedures had ruled out any renal, abdominal or spinal conditions to justify pain. Notwithstanding treatment with three drugs, she had frequent hypertensive crises during which the loin pain was dramatically exacerbated. Vascular causes of the pain and hypertension were investigated and excluded. Her renal function was normal. The patient was referred to a multidisciplinary pain clinic, but had no significant improvement in her pain symptoms despite the use of non-steroidal anti-inflammatory drugs, adjuvant antidepressants and opioid-like agents. The pain and the discomfort were so severe that her quality of life was very poor, and her social and professional activities were compromised. Nephrectomy and renal autotransplantation have occasionally been performed in these cases. Since visceral pain signals flow through afferent sympathetic fibres, we felt that percutaneous catheter-based radiofrequency ablation of the renal sympathetic nerve fibres (recently introduced for the treatment of drug-resistant hypertension) could be valuable for pain relief. We treated the patient with radiofrequency ablation (Medtronic Symplicity Catheter) applied only to the right renal artery. After a 6-month follow-up, the patient is pain free and normotensive with all drugs withdrawn. She has experienced no hypertensive crises in the meantime. This observation suggests that percutaneous sympathetic denervation could prove to be an effective mini-invasive strategy for the treatment of chronic renal pain, and LPHS in particular.

  8. Effect of Atorvastatin vs. Rosuvastatin on cardiac sympathetic nerve activity in non-diabetic patients with dilated cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Tsutamoto, Takayoshi; Ibe, Kunihiro [Toyosato Hospital, Toyosato, Shiga (Japan); Sakai, Hiroshi; Yamaji, Masayuki; Kawahara, Chiho; Nakae, Ichiro; Fujii, Masanori; Yamamoto, Takashi; Horie, Minoru [Shiga Univ. of Medical Science, Faculty of Medicine, Otsu, Shiga (Japan)

    2011-08-15

    Effects of statin therapy on cardiac sympathetic nerve activity in patients with chronic heart failure (CHF) have not previously been evaluated. To compare the effects of lipophilic atorvastatin and hydrophilic rosuvastatin on cardiac sympathetic nerve activity in CHF patients with dilated cardiomyopathy (DCM), 63 stable outpatients with DCM, who were already receiving standard therapy for CHF, were randomized to atorvastatin (n=32) or rosuvastatin (n=31). We evaluated cardiac sympathetic nerve activity by cardiac {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy, hemodynamic parameters and neurohumoral factors before and after 6 months of treatment. There were no differences in the baseline characteristics of the 2 groups. In the rosuvastatin group, there were no changes in MIBG parameters, left ventricular ejection fraction or plasma levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) after 6 months of treatment. In contrast, the atorvastatin group showed a significant increase in the delayed heart/mediastinum count ratio (2.18{+-}0.4 vs. 2.36{+-}0.4, P<0.0001), and the washout rate was significantly decreased (34.8{+-}5.7 vs. 32.6{+-}6.3%, P=0.0001) after 6 months of treatment compared with the baseline values. The plasma NT-proBNP level was also significantly decreased (729{+-}858 vs. 558{+-}747 pg/ml, P=0.0139). Lipophilic atorvastatin but not hydrophilic rosuvastatin improves cardiac sympathetic nerve activity in CHF patients with DCM. (author)

  9. Prediction of cardiac sympathetic nerve activity and cardiac functional outcome after treatment in patients with dilated cardiomyopathy. Examination using dobutamine gated blood pool scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu; Toyama, Takuji; Iwasaki, Tsutomu; Suzuki, Tadashi [Gunma Univ., Maebashi (Japan). School of Medicine; Hoshizaki, Hiroshi; Oshima, Shigeru; Taniguchi, Koichi; Nagai, Ryozo

    2000-07-01

    This study evaluated whether dobutamine gated blood pool scintigraphy can predict improvement of cardiac sympathetic nerve activity and cardiac function. Sixteen patients (10 men and 6 women, mean age 59{+-}13 years) with dilated cardiomyopathy underwent dobutamine gated blood pool scintigraphy to measure left ventricular ejection fraction (LVEF) using tracer at 0, 5, 10 and 15 {mu}g/kg/min before treatment. Patients were divided into good responders (LVEF increase {>=}15%) 8 patients (GR Group) and poor responders (LVEF increase <15%) 8 patients (PR Group) after treatment with {beta}-blocker or amiodarone with a background treatment of digitalis, diuretics and angiotensin converting enzyme inhibitor. I-123 metaiodobenzylguanidine (MIBG) imaging to evaluate cardiac sympathetic nerve activity and echocardiography were performed before and at one year after treatment. MIBG imaging was obtained 4 hours after tracer injection, and the heart/mediastinum count ratio (H/M ratio) calculated from the anterior planar image and the total defect score (TDS) from the single photon emission computed tomography image. LVEF and left ventricular endo-diastolic dimension (LVDd) were measured by echocardiography and New York Heart Association (NYHA) functional class was evaluated. The GR Group showed TDS decreased from 28{+-}6 to 17{+-}12 (p<0.05), H/M ratio increased from 1.79{+-}0.26 to 2.07{+-}0.32 (p<0.05), LVEF increased from 29{+-}8% to 48{+-}10% (p<0.01), and LVDd decreased from 65{+-}4 mm to 58{+-}5 mm (p<0.05). In contrast, the PR group showed no significant changes in TDS. H/M ratio, LVEF and LVDd. NYHA functional class improved in both groups. The improvement was better in the GR Group than in the PR group. Dobutamine gated blood pool scintigraphy is useful to predict the improvement of the cardiac sympathetic nerve activity and cardiac function, and symptoms after treatment in patients with dilated cardiomyopathy. (author)

  10. Regional sympathetic denervation after myocardial infarction in humans detected noninvasively using I-123-metaiodobenzylguanidine

    Energy Technology Data Exchange (ETDEWEB)

    Stanton, M.S.; Tuli, M.M.; Radtke, N.L.; Heger, J.J.; Miles, W.M.; Mock, B.H.; Burt, R.W.; Wellman, H.N.; Zipes, D.P. (Indiana Univ. School of Medicine, IN (USA))

    1989-11-15

    Transmural myocardial infarction in dogs produces denervation of sympathetic nerves in viable myocardium apical to the infarct that may be arrhythmogenic. It is unknown whether sympathetic denervation occurs in humans. The purpose of this study was to use iodine-123-metaiodobenzylguanidine (MIBG), a radiolabeled guanethidine analog that is actively taken up by sympathetic nerve terminals, to image noninvasively the cardiac sympathetic nerves in patients with and without ventricular arrhythmias after myocardial infarction. Results showed that 10 of 12 patients with spontaneous ventricular tachyarrhythmias after myocardial infarction exhibited regions of thallium-201 uptake indicating viable perfused myocardium, with no MIBG uptake. Such a finding is consistent with sympathetic denervation. One patient had frequent episodes of nonsustained ventricular tachycardia induced at exercise testing that was eliminated by beta-adrenoceptor blockade. Eleven of the 12 patients had ventricular tachycardia induced at electrophysiologic study and metoprolol never prevented induction. Sympathetic denervation was also detected in two of seven postinfarction patients without ventricular arrhythmias. Normal control subjects had no regions lacking MIBG uptake. This study provides evidence that regional sympathetic denervation occurs in humans after myocardial infarction and can be detected noninvasively by comparing MIBG and thallium-201 images. Although the presence of sympathetic denervation may be related to the onset of spontaneous ventricular tachyarrhythmias in some patients, it does not appear to be related to sustained ventricular tachycardia induced at electrophysiologic study.

  11. Assessment of cardiac sympathetic nerve integrity with positron emission tomography

    International Nuclear Information System (INIS)

    Raffel, David M.; Wieland, Donald M.

    2001-01-01

    The autonomic nervous system plays a critical role in the regulation of cardiac function. Abnormalities of cardiac innervation have been implicated in the pathophysiology of many heart diseases, including sudden cardiac death and congestive heart failure. In an effort to provide clinicians with the ability to regionally map cardiac innervation, several radiotracers for imaging cardiac sympathetic neurons have been developed. This paper reviews the development of neuronal imaging agents and discusses their emerging role in the noninvasive assessment of cardiac sympathetic innervation

  12. CT-clinical approach to patients with symptoms related to the V, VII, IX-XII cranial nerves and cervical sympathetics

    International Nuclear Information System (INIS)

    Kalovidouris, A.; Mancuso, A.A.; Dillon, W.

    1984-01-01

    Forty-three patients who had signs and symptoms possibly related to the extracranial course of cranial nerves V, VII, IX, X-XII, and the cervical sympathetics were examined prospectively using high resolution CT to obtain images of thin sections during rapid drip infusion of contrast material. Anatomic areas in the scan protocols included the posterior fossa, cavernous and paranasal sinuses, skull base, temporal bone, nasopharynx, parotid gland, tongue base, and neck. Nine of the 23 patients with possible fifth nerve deficits had extracranial structural lesions that explained the symptoms; none of these nine, however, had typical trigeminal neuralgia. Of eight patients with peripheral seventh nerve abnormalities, two had positive findings on scans. Of five patients presenting with referred ear pain, three had carcinoma of the upper aerodigestive tract. The authors' experience suggests that patients at high risk for structural lesions responsible for cranial nerve deficits can be selected by clinical criteria. Protocols for each clinical setting are presented

  13. Influence of the polyol pathway on norepinephrine transporter reduction in diabetic cardiac sympathetic nerves: implications for heterogeneous accumulation of MIBG

    International Nuclear Information System (INIS)

    Kiyono, Yasushi; Kajiyama, Satomi; Fujiwara, Hiromi; Kanegawa, Naoki; Saji, Hideo

    2005-01-01

    Cardiac scintigraphic studies using 123 I-labeled metaiodobenzylguanidine ([ 123 I]MIBG) have demonstrated heterogeneous myocardial accumulation of MIBG in diabetes. The accumulation has been found to correlate with a heterogeneous decrease in the expression of norepinephrine transporter (NET). In diabetic peripheral nerve tissue, polyol pathways are activated and cause nerve dysfunction and degeneration. However, there has been little research on the polyol pathway and cardiac sympathetic nerves. Therefore, to assess the influence of the polyol pathway on cardiac sympathetic nervous function, we investigated the regional accumulation of MIBG and NET protein expression in diabetic model rats treated with aldose reductase inhibitor (ARI) for the blockade of polyol pathways. Rats were given a single intravenous injection of streptozotocin (n=76, STZ-D rats). Starting the day after STZ injection, ARI was administered daily to 42 of the rats for 4 weeks (ARI-D rats). To assess the cardiac sympathetic nervous function, [ 125 I]MIBG autoradiographic experiments were carried out. Finally, NET protein expression was assessed with a saturation binding assay. The myocardial sorbitol concentration was significantly higher in STZ-D rats than in ARI-D rats. There was no heterogeneous accumulation of MIBG in ARI-D rats. There was a heterogeneous decrease of NET expression in STZ-D rats, but not in ARI-D or control rats. The gathered data indicate that the enhanced polyol pathway correlates with the decrease in regional cardiac sympathetic nervous function, and this impairment may lead to the reduction of NET protein in cardiac sympathetic nerves of the diabetic inferior wall. (orig.)

  14. Change in sympathetic nerve firing pattern associated with dietary weight loss in the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Elisabeth Annie Lambert

    2011-08-01

    Full Text Available Sympathetic activation in subjects with the metabolic syndrome (MS plays a role in the pathogenesis of cardiovascular disease development. Diet-induced weight loss decreases sympathetic outflow. However the mechanisms that account for sympathetic inhibition are not known. We sought to provide a detailed description of the sympathetic response to diet by analyzing the firing behavior of single-unit sympathetic nerve fibres. Fourteen subjects (57±2 years, 9 men, 5 females fulfilling ATP III criteria for the MS underwent a 3-month low calorie diet. Metabolic profile, hemodynamic parameters and multi-unit and single unit muscle sympathetic nerve activity (MSNA, microneurography were assessed prior to and at the end of the diet. Patients’ weight dropped from 96±4 to 88±3 kg (P<0.001. This was associated with a decrease in systolic and diastolic blood pressure (-12 ±3 and -5±2 mmHg, P<0.05, and in heart rate (-7±2 bpm, P<0.01 and an improvement in all metabolic parameters (fasting glucose: -0.302.1±0.118 mmol/l, total cholesterol: -0.564±0.164 mmol/l, triglycerides: -0.414±0.137 mmol/l, P<0.05. Multi-unit MSNA decreased from 68±4 to 59±5 bursts per 100 heartbeats (P<0.05. Single-unit MSNA indicated that the firing rate of individual vasoconstrictor fibres decreased from 59±10 to 32±4 spikes per 100 heart beats (P<0.05. The probability of firing decreased from 34±5 to 23±3 % of heartbeats (P<0.05, and the incidence of multiple firing decreased from 14±4 to 6±1 % of heartbeats (P<0.05. Cardiac and sympathetic baroreflex function were significantly improved (cardiac slope: 6.57±0.69 to 9.57±1.20 msec.mmHg-1; sympathetic slope: -3.86±0.34 to -5.05±0.47 bursts per 100 heartbeats.mmHg-1 P<0.05 for both. Hypocaloric diet decreased sympathetic activity and improved hemodynamic and metabolic parameters. The sympathoinhibition associated with weight loss involves marked changes, not only in the rate but also in the firing pattern of

  15. Muscle sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy individuals.

    Directory of Open Access Journals (Sweden)

    Yrsa Bergmann Sverrisdóttir

    Full Text Available BACKGROUND: Evidence from animal studies indicates the importance of an interaction between the sympathetic nervous system and the endothelium for cardiovascular regulation. However the interaction between these two systems remains largely unexplored in humans. The aim of this study was to investigate whether directly recorded sympathetic vasoconstrictor outflow is related to a surrogate marker of endothelial function in healthy individuals. METHODS AND RESULTS: In 10 healthy normotensive subjects (3 f/7 m, (age 37+/-11 yrs, (BMI 24+/-3 kg/m(2 direct recordings of sympathetic action potentials to the muscle vascular bed (MSNA were performed and endothelial function estimated with the Reactive Hyperaemia- Peripheral Arterial Tonometry (RH-PAT technique. Blood samples were taken and time spent on leisure-time physical activities was estimated. In all subjects the rate between resting flow and the maximum flow, the Reactive Hyperemic index (RH-PAT index, was within the normal range (1.9-3.3 and MSNA was as expected for age and gender (13-44 burst/minute. RH-PAT index was inversely related to MSNA (r = -0.8, p = 0.005. RH-PAT index and MSNA were reciprocally related to time (h/week spent on physical activity (p = 0.005 and p = 0.006 respectively and platelet concentration (PLT (p = 0.02 and p = 0.004 respectively. CONCLUSIONS: Our results show that sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy normotensive individuals, indicating that sympathetic outflow may be modulated by changes in endothelial function. In this study time spent on physical activity is identified as a predictor of sympathetic nerve activity and endothelial function in a group of healthy individuals. The results are of importance in understanding mechanisms underlying sympathetic activation in conditions associated with endothelial dysfunction and emphasise the importance of a daily exercise routine for maintenance of cardiovascular

  16. Imbalance between sympathetic and sensory innervation in peritoneal endometriosis.

    Science.gov (United States)

    Arnold, Julia; Barcena de Arellano, Maria L; Rüster, Carola; Vercellino, Giuseppe F; Chiantera, Vito; Schneider, Achim; Mechsner, Sylvia

    2012-01-01

    To investigate possible mechanisms of pain pathophysiology in patients with peritoneal endometriosis, a clinical study on sensory and sympathetic nerve fibre sprouting in endometriosis was performed. Peritoneal lesions (n=40) and healthy peritoneum (n=12) were immunostained and analysed with anti-protein gene product 9.5 (PGP 9.5), anti-substance P (SP) and anti-tyrosine hydroxylase (TH), specific markers for intact nerve fibres, sensory nerve fibres and sympathetic nerve fibres, respectively, to identify the ratio of sympathetic and sensory nerve fibres. In addition, immune cell infiltrates in peritoneal endometriotic lesions were analysed and the nerve growth factor (NGF) and interleukin (IL)-1β expression was correlate with the nerve fibre density. Peritoneal fluids from patients with endometriosis (n=40) and without endometriosis (n=20) were used for the in vitro neuronal growth assay. Cultured chicken dorsal root ganglia (DRG) and sympathetic ganglia were stained with anti-growth associated protein 43 (anti-GAP 43), anti-SP and anti-TH. We could detect an increased sensory and decreased sympathetic nerve fibres density in peritoneal lesions compared to healthy peritoneum. Peritoneal fluids of patients with endometriosis compared to patients without endometriosis induced an increased sprouting of sensory neurites from DRG and decreased neurite outgrowth from sympathetic ganglia. In conclusion, this study demonstrates an imbalance between sympathetic and sensory nerve fibres in peritoneal endometriosis, as well as an altered modulation of peritoneal fluids from patients with endometriosis on sympathetic and sensory innervation which might directly be involved in the maintenance of inflammation and pain. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Sympathetic network drive during water deprivation does not increase respiratory or cardiac rhythmic sympathetic nerve activity.

    Science.gov (United States)

    Holbein, Walter W; Toney, Glenn M

    2013-06-15

    Effects of water deprivation on rhythmic bursting of sympathetic nerve activity (SNA) were investigated in anesthetized, bilaterally vagotomized, euhydrated (control) and 48-h water-deprived (WD) rats (n = 8/group). Control and WD rats had similar baseline values of mean arterial pressure, heart rate, end-tidal CO2, and central respiratory drive. Although integrated splanchnic SNA (sSNA) was greater in WD rats than controls (P analysis of respiratory rhythmic bursting of sSNA revealed that inspiratory rhythmic burst amplitude was actually smaller (P analysis revealed that water deprivation had no effect on either the amplitude or periodicity of the cardiac rhythmic oscillation of sSNA. Collectively, these data indicate that the increase of sSNA produced by water deprivation is not attributable to either increased respiratory or cardiac rhythmic burst discharge. Thus the sympathetic network response to acute water deprivation appears to differ from that of chronic sympathoexcitation in neurogenic forms of arterial hypertension, where increased respiratory rhythmic bursting of SNA and baroreflex adaptations have been reported.

  18. Contemporary review on the pathogenesis of takotsubo syndrome: The heart shedding tears: Norepinephrine churn and foam at the cardiac sympathetic nerve terminals.

    Science.gov (United States)

    Y-Hassan, Shams; De Palma, Rodney

    2017-02-01

    Takotsubo syndrome (TS), an increasingly recognized acute cardiac disease entity, is characterized by a unique pattern of circumferential and typically regional left ventricular wall motion abnormality resulting in a conspicuous transient ballooning of the left ventricle during systole. The mechanism of the disease remains elusive. However, the sudden onset of acute myocardial stunning in a systematic pattern extending beyond a coronary artery territory; the history of a preceding emotional or physical stress factor in two thirds of cases; the signs of sympathetic denervation at the regions of left ventricular dysfunction on sympathetic scintigraphy; the finding of myocardial edema and other signs consistent with (catecholamine-induced) myocarditis shown by cardiac magnetic resonance imaging; and the contraction band necrosis on histopathological examination all argue strongly for the involvement of the cardiac sympathetic nervous system in the pathogenesis of TS. In this narrative review, extensive evidence in support of local cardiac sympathetic nerve hyperactivation, disruption and norepinephrine spillover causing TS in predisposed patients is provided. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. The morphological substrate for Renal Denervation: Nerve distribution patterns and parasympathetic nerves. A post-mortem histological study.

    Science.gov (United States)

    van Amsterdam, Wouter A C; Blankestijn, Peter J; Goldschmeding, Roel; Bleys, Ronald L A W

    2016-03-01

    Renal Denervation as a possible treatment for hypertension has been studied extensively, but knowledge on the distribution of nerves surrounding the renal artery is still incomplete. While sympathetic and sensory nerves have been demonstrated, there is no mention of the presence of parasympathetic nerve fibers. To provide a description of the distribution patterns of the renal nerves in man, and, in addition, provide a detailed representation of the relative contribution of the sympathetic, parasympathetic and afferent divisions of the autonomic nervous system. Renal arteries of human cadavers were each divided into four longitudinal segments and immunohistochemically stained with specific markers for afferent, parasympathetic and sympathetic nerves. Nerve fibers were semi-automatically quantified by computerized image analysis, and expressed as cross-sectional area relative to the distance to the lumen. A total of 3372 nerve segments were identified in 8 arteries of 7 cadavers. Sympathetic, parasympathetic and afferent nerves contributed for 73.5% (95% CI: 65.4-81.5%), 17.9% (10.7-25.1%) and 8.7% (5.0-12.3%) of the total cross-sectional nerve area, respectively. Nerves are closer to the lumen in more distal segments and larger bundles that presumably innervate the kidney lie at 1-3.5mm distance from the lumen. The tissue-penetration depth of the ablation required to destroy 50% of the nerve fibers is 2.37 mm in the proximal segment and 1.78 mm in the most distal segments. Sympathetic, parasympathetic and afferent nerves exist in the vicinity of the renal artery. The results warrant further investigation of the role of the parasympathetic nervous system on renal physiology, and may contribute to refinement of the procedure by focusing the ablation on the most distal segment. Copyright © 2015 Elsevier GmbH. All rights reserved.

  20. Exposure to a high-fat diet during development alters leptin and ghrelin sensitivity and elevates renal sympathetic nerve activity and arterial pressure in rabbits.

    Science.gov (United States)

    Prior, Larissa J; Davern, Pamela J; Burke, Sandra L; Lim, Kyungjoon; Armitage, James A; Head, Geoffrey A

    2014-02-01

    Exposure to maternal obesity or a maternal diet rich in fat during development may have adverse outcomes in offspring, such as the development of obesity and hypertension. The present study examined the effect of a maternal high-fat diet (m-HFD) on offspring blood pressure and renal sympathetic nerve activity, responses to stress, and sensitivity to central administration of leptin and ghrelin. Offspring of New Zealand white rabbits fed a 13% HFD were slightly heavier than offspring from mothers fed a 4% maternal normal fat diet (Pfat pad mass (P=0.015). Mean arterial pressure, heart rate, and renal sympathetic nerve activity at 4 months of age were 7%, 7%, and 24% greater, respectively (Pfat diet rabbits, and the renal sympathetic nerve activity response to airjet stress was enhanced in the m-HFD group. m-HFD offspring had markedly elevated pressor and renal sympathetic nerve activity responses to intracerebroventricular leptin (5-100 µg) and enhanced sympathetic responses to intracerebroventricular ghrelin (1-5 nmol). In contrast, there was resistance to the anorexic effects of intracerebroventricular leptin and less neuronal activation as detected by Fos immunohistochemistry in the arcuate (-57%; Pfat diet rabbits. We conclude that offspring from mothers consuming an HFD exhibit an adverse cardiovascular profile in adulthood because of altered central hypothalamic sensitivity to leptin and ghrelin.

  1. Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke [Nihon Univ., Tokyo (Japan). School of Medicine

    2000-12-01

    Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5{+-}6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33{+-}0.22 in chronic heart failure class I, 2.50{+-}0.34 in class II, 1.95{+-}0.61 in class III, and 1.39{+-}0.29 in class IV (p<0.05). %WR was 24.8{+-}12.8% in chronic heart failure class I, 23.3{+-}10.2% in class II, 49.2{+-}24.5% in class III, and 66.3{+-}26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

  2. Acute sex hormone suppression reduces skeletal muscle sympathetic nerve activity.

    Science.gov (United States)

    Day, Danielle S; Gozansky, Wendolyn S; Bell, Christopher; Kohrt, Wendy M

    2011-10-01

    Comparisons of sympathetic nervous system activity (SNA) between young and older women have produced equivocal results, in part due to inadequate control for potential differences in sex hormone concentrations, age, and body composition. The aim of the present study was to determine the effect of a short-term reduction in sex hormones on tonic skeletal muscle sympathetic nerve activity (MSNA), an indirect measure of whole body SNA, using an experimental model of sex hormone deficiency in young women. We also assessed the independent effects of estradiol and progesterone add-back therapy on MSNA. MSNA was measured in 9 women (30±2 years; mean±SE) on three separate occasions: during the mid-luteal menstrual cycle phase, on the fifth day of gonadotropin-releasing hormone antagonist (GnRHant) administration, and after 5 days add-back of either estradiol (n=4) or progesterone (n=3) during continued GnRHant administration. In response to GnRHant, there were significant reductions in serum estradiol and progesterone (both psuppression attenuates MSNA and that this may be related to the suppression of progesterone rather than estradiol.

  3. Comparison of sympathetic nerve responses to neck and forearm isometric exercise

    Science.gov (United States)

    Steele, S. L. Jr; Ray, C. A.

    2000-01-01

    PURPOSE: Although the autonomic and cardiovascular responses to arm and leg exercise have been studied, the sympathetic adjustments to exercise of the neck have not. The purpose of the present study was twofold: 1) to determine sympathetic and cardiovascular responses to isometric contractions of the neck extensors and 2) to compare sympathetic and cardiovascular responses to isometric exercise of the neck and forearm. METHODS: Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate were measured in nine healthy subjects while performing isometric neck extension (INE) and isometric handgrip (IHG) in the prone position. After a 3-min baseline period, subjects performed three intensities of INE for 2.5 min each: 1) unloaded (supporting head alone), 2) 10% maximal voluntary contraction (MVC), and 3) 30% MVC, then subjects performed two intensities (10% and 30% MVC) of IHG for 2.5 min. RESULTS: Supporting the head by itself did not significantly change any of the variables. During [NE, MAP significantly increased by 10 +/- 2 and 31 +/- 4 mm Hg and MSNA increased by 67 +/- 46 and 168 +/- 36 units/30 s for 10% and 30% MVC, respectively. IHG and INE evoked similar responses at 10% MVC, but IHG elicited higher peak MAP and MSNA at 30% MVC (37 +/- 7 mm Hg (P INE can elicit marked increases in MSNA and cardiovascular responses but that it evokes lower peak responses as compared to IHG. We speculate that possible differences in muscle fiber type composition, muscle mass, and/or muscle architecture of the neck and forearm are responsible for these differences in peak responses.

  4. Median Sacral Artery, Sympathetic Nerves, and the Coccygeal Body: A Study Using Serial Sections of Human Embryos and Fetuses.

    Science.gov (United States)

    Jin, Zhe Wu; Cho, Kwang Ho; Jang, Hyung Suk; Murakami, Gen; Rodríguez-Vázquez, Jose Francisco

    2016-07-01

    To examine how the median sacral artery (MSA) is involved with the coccygeal body or glomus coccygeum, we studied serial frontal or sagittal sections of 14 embryos (approximately 5-6 weeks of gestation) and 12 fetuses (10-18 weeks). At five weeks, the caudal end of the dorsal aorta (i.e., MSA) accompanied putative sympathetic ganglion cells in front of the upper coccygeal and lower sacral vertebrae. At six weeks, a candidate for the initial coccygeal body was identified as a longitudinal arterial plexus involving nerve fibers and sympathetic ganglion cells between arteries. At 10-18 weeks, the MSA exhibited a highly tortuous course at the lower sacral and coccygeal levels, and was attached to and surrounded by veins, nerve fibers, and sympathetic ganglion cells near and between the bilateral origins of the levator ani muscle. Immunohistochemistry demonstrated expression of tyrosine hydroxylase and chromogranin A in the nerves. However, throughout the stages examined, we found no evidence suggestive of an arteriovenous anastomosis, such as well-developed smooth muscle. An acute anterior flexure of the vertebrae at the lower sacrum, as well as regression of the secondary neural tube, seemed to induce arterial plexus formation from an initial straight MSA. Nerves and ganglion cells were likely to be secondarily involved with the plexus because of the close topographical relationship. However, these nerves might play a major role in the extreme change into adult morphology. An arteriovenous anastomosis along the MSA might be an overinterpretation, at least in the prenatal human. Anat Rec, 299:819-827, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

    International Nuclear Information System (INIS)

    Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke

    2000-01-01

    Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5±6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33±0.22 in chronic heart failure class I, 2.50±0.34 in class II, 1.95±0.61 in class III, and 1.39±0.29 in class IV (p<0.05). %WR was 24.8±12.8% in chronic heart failure class I, 23.3±10.2% in class II, 49.2±24.5% in class III, and 66.3±26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

  6. Study of sympathetic nerve activity in young Indian obese individuals

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    B Kalpana

    2013-01-01

    Full Text Available Background: Obesity is the culmination of a chronic imbalance between energy intake and energy expenditure. This energy balance can be potentially affected by the activity of autonomic nervous system (ANS. Altered sympathetic nerve function may be of importance in obesity. Objective: The present study is an attempt to pinpoint the defect (if any in the activity of sympathetic limb of the ANS in obesity, by subjecting to isometric exercise stress. Materials and Methods: A total of 81 females belonging to the age group of 18-22 years were recruited for the study. The participants were divided into two groups as normal weight and obese based on WHO guidelines for Asia Pacific region. After recording the resting blood pressure, they were subjected to isometric exercise by Handgrip dynamometer. Blood pressure was recorded again, and the difference was noted down. All recorded parameters were compared between two groups using unpaired t test. The relationship between body mass index (BMI and rise in diastolic pressure was quantified by Pearson′s correlation test. A P value less than 0.05 was considered as significant. Results: In obese, the diastolic pressure was significantly higher at rest, but showed reduced rise during handgrip test in comparison with normal weight individuals. Also, the rise in diastolic pressure exhibited a negative relation with BMI. Conclusion: The result is suggestive of impaired autonomic function at rest and reduced sympathetic activity in the group of obese when subjected to stress. This could make them more prone for future development of hypertension or other cardiovascular disorders.

  7. Effect of Switching from Cilnidipine to Azelnidipine on Cardiac Sympathetic Nerve Function in Patients with Heart Failure Preserved Ejection Fraction.

    Science.gov (United States)

    Kiuchi, Shunsuke; Hisatake, Shinji; Kabuki, Takayuki; Oka, Takashi; Dobashi, Shintaro; Fujii, Takahiro; Ikeda, Takanori

    2018-01-27

    Cardiac sympathetic nerve activity is known to play a key role in the development and progression of heart failure (HF). Azelnidipine, an L-type calcium channel blocker (CCB), inhibits the sympathetic nerve activity of the central system. In contrast, cilnidipine, an N-type CCB, inhibits the sympathetic nerve activity of the peripheral system. CCBs are recommended as class IIa in patients with HF preserved ejection fraction (HFpEF); however, there are no comparative data on the difference in effect of cilnidipine and azelnidipine in patients with HFpEF and hypertension. We investigated the difference in effect of azelnidipine compared with cilnidipine in patients with HFpEF. Twenty-four consecutive HF patients who received angiotensin II type1a receptor blocker and beta blocker from April 2013 to January 2015 were enrolled. Cilnidipine was switched to azelnidipine during the follow-up period. Blood pressures, heart rate, blood tests, echocardiography, and 123 I-metaiodobenzylguanidine (MIBG) cardiac-scintigraphy were measured before and after 6 months from azelnidipine administration. B-type natriuretic peptide tended to decrease after switching to azelnidipine; however, there were no significant differences between the pre-state and post-state (pre-state: 118.5 pg/mL and post-state: 78.4 pg/mL, P = 0.137). Other laboratory findings, including catecholamine, also did not change significantly. In echocardiography, there were no significant differences in systolic and diastolic functions at the pre-state and post-state. As for MIBG, there were no significant changes in heart/mediastinum ratio. However, washout rate was significantly reduced (pre-state: 42.9 and post-state: 39.6, P = 0.030). Azelnidipine improved the dysfunction of cardiac sympathetic nerve activity compared with cilnidipine in patients with HFpEF.

  8. Sympathetic block by metal clips may be a reversible operation

    DEFF Research Database (Denmark)

    Thomsen, Lars L; Mikkelsen, Rasmus T; Derejko, Miroslawa

    2014-01-01

    , but the question of reversibility remains controversial. Two recent experimental studies found severe histological signs of nerve damage 4-6 weeks after clip removal, but they only used conventional histopathological staining methods. METHODS: Thoracoscopic clipping of the sympathetic trunk was performed in adult...... the sympathetic chain vary tremendously. Most surgeons transect or resect the sympathetic chain, but application of a metal clip that blocks transmission of nerve impulses in the sympathetic chain is used increasingly worldwide. This approach offers potential reversibility if patients regret surgery...... suggests in theory that application of metal clips to the sympathetic chain is a reversible procedure if only the observation period is prolonged. Further studies with longer periods between application and removal as well as investigations of nerve conduction should be encouraged, because we do not know...

  9. Relation between myocardial response to dobutamine stress and sympathetic nerve activation in patients with idiopathic dilated cardiomyopathy. A comparison of 123I-MIBG scintigraphic and echocardiographic data

    International Nuclear Information System (INIS)

    Naruse, Hitoshi; Arii, Tohru; Kondo, Tomohiro

    2000-01-01

    It is likely that a close association exists between findings obtained by two methods: dobutamine stress echocardiography and 123 I-MIBG scintigraphy. Both of these methods are associated with β-adrenergic receptor mechanisms. This study was conducted to demonstrate the relation between myocardial response to dobutamine stress and sympathetic nerve release of norepinephrine in the failing heart. In 12 patents with heart failure due to idiopathic dilated cardiomyopathy, the myocardial effects of dobutamine stress were evaluated by low-dose dobutamine stress echocardiography; and sympathetic nerve function was evaluated by scintigraphic imaging with iodine-123[ 123 I]meta-iodobenzylguanidine (MIBG), an analogue of norepinephrine. Echocardiography provided quantitative assessment of wall motion and left ventricular dilation; radiotracer studies with 123 I-MIBG provided quantitative assessment of the heart-to-mediastinum (H/M) uptake ratio and washout rate. Results showed that H/M correlated with baseline wall motion (r=0.682, p=0.0146), wall motion after dobutamine stress (r=0.758, p=0.0043), the change in wall motion (r=0.667, p=0.0178), and with left ventricular diastolic diameter (r=0.837, p=0.0007). In addition, the 123 I-MIBG washout rate correlated with baseline wall motion (r=0.608, p=0.0360), wall motion after dobutamine stress (r=0.703, p=0.0107), and with the change in wall motion (r=0.664, p=0.0185). Wall motion, especially in the myocardial response to dobutamine stress, is related to sympathetic nerve activity in heart failure. (author)

  10. Functional role of diverse changes in sympathetic nerve activity in regulating arterial pressure during REM sleep.

    Science.gov (United States)

    Yoshimoto, Misa; Yoshida, Ikue; Miki, Kenju

    2011-08-01

    This study aimed to investigate whether REM sleep evoked diverse changes in sympathetic outflows and, if so, to elucidate why REM sleep evokes diverse changes in sympathetic outflows. Male Wistar rats were chronically implanted with electrodes to measure renal (RSNA) and lumbar sympathetic nerve activity (LSNA), electroencephalogram, electromyogram, and electrocardiogram, and catheters to measure systemic arterial and central venous pressure; these parameters were measured simultaneously and continuously during the sleep-awake cycle in the same rat. REM sleep resulted in a step reduction in RNSA by 36.1% ± 2.7% (P sleep. In contrast to REM sleep, RSNA, LSNA, systemic arterial pressure, and heart rate increased in a unidirectional manner associated with increases in physical activity levels in the order from NREM sleep, quiet awake, moving, and grooming state. Thus, the relationship between RSNA vs. LSNA and systemic arterial pressure vs. heart rate observed during REM sleep was dissociated compared with that obtained during the other behavioral states. It is suggested that the diverse changes in sympathetic outflows during REM sleep may be needed to increase systemic arterial pressure by balancing vascular resistance between muscles and vegetative organs without depending on the heart.

  11. Can nerve regeneration on an artificial nerve conduit be enhanced by ethanol-induced cervical sympathetic ganglion block?

    Directory of Open Access Journals (Sweden)

    Yoshiki Shionoya

    Full Text Available This study aimed to determine whether nerve regeneration by means of an artificial nerve conduit is promoted by ethanol-induced cervical sympathetic ganglion block (CSGB in a canine model. This study involved two experiments-in part I, the authors examined the effect of CSGB by ethanol injection on long-term blood flow to the orofacial region; part II involved evaluation of the effect of CSGB by ethanol injection on inferior alveolar nerve (IAN repair using polyglycolic acid-collagen tubes. In part I, seven Beagles were administered left CSGB by injection of 99.5% ethanol under direct visualization by means of thoracotomy, and changes in oral mucosal blood flow in the mental region and nasal skin temperature were evaluated. The increase in blood flow on the left side lasted for 7 weeks, while the increase in average skin temperature lasted 10 weeks on the left side and 3 weeks on the right. In part II, fourteen Beagles were each implanted with a polyglycolic acid-collagen tube across a 10-mm gap in the left IAN. A week after surgery, seven of these dogs were administered CSGB by injection of ethanol. Electrophysiological findings at 3 months after surgery revealed significantly higher sensory nerve conduction velocity and recovery index (ratio of left and right IAN peak amplitudes after nerve regeneration in the reconstruction+CSGB group than in the reconstruction-only group. Myelinated axons in the reconstruction+CSGB group were greater in diameter than those in the reconstruction-only group. Administration of CSGB with ethanol resulted in improved nerve regeneration in some IAN defects. However, CSGB has several physiological effects, one of which could possibly be the long-term increase in adjacent blood flow.

  12. Can nerve regeneration on an artificial nerve conduit be enhanced by ethanol-induced cervical sympathetic ganglion block?

    Science.gov (United States)

    Sunada, Katsuhisa; Shigeno, Keiji; Nakada, Akira; Honda, Michitaka; Nakamura, Tatsuo

    2017-01-01

    This study aimed to determine whether nerve regeneration by means of an artificial nerve conduit is promoted by ethanol-induced cervical sympathetic ganglion block (CSGB) in a canine model. This study involved two experiments—in part I, the authors examined the effect of CSGB by ethanol injection on long-term blood flow to the orofacial region; part II involved evaluation of the effect of CSGB by ethanol injection on inferior alveolar nerve (IAN) repair using polyglycolic acid-collagen tubes. In part I, seven Beagles were administered left CSGB by injection of 99.5% ethanol under direct visualization by means of thoracotomy, and changes in oral mucosal blood flow in the mental region and nasal skin temperature were evaluated. The increase in blood flow on the left side lasted for 7 weeks, while the increase in average skin temperature lasted 10 weeks on the left side and 3 weeks on the right. In part II, fourteen Beagles were each implanted with a polyglycolic acid-collagen tube across a 10-mm gap in the left IAN. A week after surgery, seven of these dogs were administered CSGB by injection of ethanol. Electrophysiological findings at 3 months after surgery revealed significantly higher sensory nerve conduction velocity and recovery index (ratio of left and right IAN peak amplitudes) after nerve regeneration in the reconstruction+CSGB group than in the reconstruction-only group. Myelinated axons in the reconstruction+CSGB group were greater in diameter than those in the reconstruction-only group. Administration of CSGB with ethanol resulted in improved nerve regeneration in some IAN defects. However, CSGB has several physiological effects, one of which could possibly be the long-term increase in adjacent blood flow. PMID:29220373

  13. Imaging the trigeminal nerve

    International Nuclear Information System (INIS)

    Borges, Alexandra; Casselman, Jan

    2010-01-01

    Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

  14. Imaging the trigeminal nerve

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Radiology Department, Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Rua Prof. Lima Basto, 1093, Lisboa (Portugal)], E-mail: borgalexandra@gmail.com; Casselman, Jan [Department of Radiology, A. Z. St Jan Brugge and A. Z. St Augustinus Antwerpen Hospitals (Belgium)

    2010-05-15

    Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

  15. The articulo-cardiac sympathetic reflex in spinalized, anesthetized rats.

    Science.gov (United States)

    Nakayama, Tomohiro; Suzuki, Atsuko; Ito, Ryuzo

    2006-04-01

    Somatic afferent regulation of heart rate by noxious knee joint stimulation has been proven in anesthetized cats to be a reflex response whose reflex center is in the brain and whose efferent arc is a cardiac sympathetic nerve. In the present study we examined whether articular stimulation could influence heart rate by this efferent sympathetic pathway in spinalized rats. In central nervous system (CNS)-intact rats, noxious articular movement of either the knee or elbow joint resulted in an increase in cardiac sympathetic nerve activity and heart rate. However, although in acutely spinalized rats a noxious movement of the elbow joint resulted in a significant increase in cardiac sympathetic nerve activity and heart rate, a noxious movement of the knee joint had no such effect and resulted in only a marginal increase in heart rate. Because this marginal increase was abolished by adrenalectomy suggests that it was due to the release of adrenal catecholamines. In conclusion, the spinal cord appears to be capable of mediating, by way of cardiac sympathetic nerves, the propriospinally induced reflex increase in heart rate that follows noxious stimulation of the elbow joint, but not the knee joint.

  16. Usefulness of cardiac 125I-metaiodobenzylguanidine uptake for evaluation of cardiac sympathetic nerve abnormalities in diabetic rats

    International Nuclear Information System (INIS)

    Abe, Nanami; Kashiwagi, Atsunori; Shigeta, Yukio

    1992-01-01

    We investigated cardiac sympathetic nerve abnormalities in streptozocin-induced diabetic rats using 125 I-metaiodobenzylguanidine (MIBG). The radioactivity ratio of cardiac tissue to 1 ml blood (H/B) was used as an index of cardiac MIBG uptake. Cardiac 125 I-MIBG uptake (H/B) in 4-, 8- and 20-wk diabetic rats was 48% lower than that in control rats. Similar results were obtained even when the data were corrected for g wet tissue weight. Although there was no improvement in H/B following 2-wk insulin treatment, the H/B ratio increased significantly, to 85% of control levels, following 4 wk insulin treatment indicating the reversibility of impaired MIBG uptake in diabetic rats. In vivo reserpine treatment resulted in a 50% reduction in the H/B value in control rats. However, the treatment did not significantly suppress uptake in diabetic rats. Cardiac norepinephrine content in both * 4- and ** 8-wk diabetic rats was significantly ( * p ** p 125 I-MIBG in diabetic rats is significantly impaired due to cardiac sympathetic nerve abnormalities. These abnormalities are reversible, however, dependent on the diabetic state. (author)

  17. The Role of Lumbar Sympathetic Nerves in Regulation of Blood Flow to Skeletal Muscle during Anaphylactic Hypotension in Anesthetized Rats.

    Directory of Open Access Journals (Sweden)

    Jie Song

    Full Text Available During hypovolemic shock, skeletal muscle blood flow could be redistributed to vital organs via vasoconstriction in part evoked by activation of the innervating sympathetic nerve activity. However, it is not well known whether this mechanism operates during anaphylactic shock. We determined the femoral artery blood flow (FBF and lumbar sympathetic nerve activity (LSNA mainly regulating the hindquater muscle blood flow during anaphylactic hypotension in anesthetized rats. Anesthetized Sprague-Dawley rats were randomly allocated to the following groups (n = 7/group: (1 non-sensitized, (2 anaphylaxis, (3 anaphylaxis-lumbar sympathectomy (LS and (4 anaphylaxis-sinoaortic denervation (SAD groups. Anaphylaxis was induced by an intravenous injection of the ovalbumin antigen to the sensitized rats. The systemic arterial pressure (SAP, heart rate (HR, central venous pressure (CVP, FBF and LSNA were continuously measured. In the anaphylaxis group, LSNA and HR increased, while SAP and FBF decreased after antigen injection. In the anaphylaxis-SAD group, LSNA did not significantly change during the early phase, but the responses of SAP and FBF were similar to those in the anaphylaxis group. In the anaphylaxis-LS group, both FBF and SAP decreased similarly to the anaphylaxis group during anaphylactic hypotension. These results indicated that LSNA increased via baroreceptor reflex, but this sympathoexcitation or LS did not affect antigen-induced decreases in FBF or SAP. Lumbar sympathetic nerves are not involved in regulation of the blood flow to the hindlimb or systemic blood pressure during anaphylactic hypotension in anesthetized rats.

  18. Defective propagation of signals generated by sympathetic nerve stimulation in the liver of connexin32-deficient mice.

    Science.gov (United States)

    Nelles, E; Bützler, C; Jung, D; Temme, A; Gabriel, H D; Dahl, U; Traub, O; Stümpel, F; Jungermann, K; Zielasek, J; Toyka, K V; Dermietzel, R; Willecke, K

    1996-09-03

    The gap junctional protein connexin32 is expressed in hepatocytes, exocrine pancreatic cells, Schwann cells, and other cell types. We have inactivated the connexin32 gene by homologous recombination in the mouse genome and have generated homozygous connexin32-deficient mice that were viable and fertile but weighed on the average approximately 17% less than wild-type controls. Electrical stimulation of sympathetic nerves in connexin32-deficient liver triggered a 78% lower amount of glucose mobilization from glycogen stores, when compared with wild-type liver. Thus, connexin32-containing gap junctions are essential in mouse liver for maximal intercellular propagation of the noradrenaline signal from the periportal (upstream) area, where it is received from sympathetic nerve endings, to perivenous (downstream) hepatocytes. In connexin32-defective liver, the amount of connexin26 protein expressed was found to be lower than in wild-type liver, and the total area of gap junction plaques was approximately 1000-fold smaller than in wild-type liver. In contrast to patients with connexin32 defects suffering from X chromosome-linked Charcot-Marie-Tooth disease (CMTX) due to demyelination in Schwann cells of peripheral nerves, connexin32-deficient mice did not show neurological abnormalities when analyzed at 3 months of age. It is possible, however, that they may develop neurodegenerative symptoms at older age.

  19. Characterization of Japanese standards for myocardial sympathetic and metabolic imaging in comparison with perfusion imaging

    International Nuclear Information System (INIS)

    Matsuo, Shinro; Nakajima, Kenichi; Okuda, Koichi; Yamashina, Shohei; Sakata, Kazuyuki; Momose, Mitsuru; Hashimoto, Jun; Kumita, Shinichiro; Kawano, Masaya

    2009-01-01

    The standard patterns of myocardial radiotracer distribution of 123 I-metaiodobenzylguanidine (MIBG) and 123 I-β-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) should be defined in a Japanese population. The purpose of this study was to present and provide data on the characteristics of MIBG and BMIPP with respect to myocardial single photon emission computed tomography. The normal database included 123 I-MIBG and 123 I-BMIPP imaging and a 99 mTc-sestamibi/tetrofosmin myocardial perfusion study. The projection images were transferred by digital imaging and communications in medicine (DICOM) format and reconstructed and analyzed with polar maps. The projection data from multiple centers were successfully transferred to a common format for single photon emission computed tomography (SPECT) reconstruction. When the average values were analyzed using a 17-segment model, MIBG uptake in the inferior and apical wall appeared to be slightly lower than anterior uptake (P 99m Tc-tracer uptake (P<0.05). Myocardial sympathetic nerve and metabolic scintigraphy data that were specific for the Japanese population were generated and found to be different from that of perfusion tracers. The normal database can serve as a standard for nuclear cardiology work conducted in Japan. (author)

  20. Chronic renin inhibition lowers blood pressure and reduces upright muscle sympathetic nerve activity in hypertensive seniors

    Science.gov (United States)

    Okada, Yoshiyuki; Jarvis, Sara S; Best, Stuart A; Bivens, Tiffany B; Adams-Huet, Beverley; Levine, Benjamin D; Fu, Qi

    2013-01-01

    Cardiovascular risk remains high in patients with hypertension even with adequate blood pressure (BP) control. One possible mechanism may be sympathetic activation via the baroreflex. We tested the hypothesis that chronic inhibition of renin reduces BP without sympathetic activation, but diuresis augments sympathetic activity in elderly hypertensives. Fourteen patients with stage-I hypertension (66 ± 5 (SD) years) were treated with a direct renin inhibitor, aliskiren (n= 7), or a diuretic, hydrochlorothiazide (n= 7), for 6 months. Muscle sympathetic nerve activity (MSNA), BP, direct renin and aldosterone were measured during supine and a graded head-up tilt (HUT; 5 min 30° and 20 min 60°), before and after treatment. Sympathetic baroreflex sensitivity (BRS) was assessed. Both groups had similar BP reductions after treatment (all P < 0.01), while MSNA responses were different between hydrochlorothiazide and aliskiren (P= 0.006 pre/post × drug). Both supine and upright MSNA became greater after hydrochlorothiazide treatment (supine, 72 ± 18 post vs. 64 ± 15 bursts (100 beats)−1 pre; 60° HUT, 83 ± 10 vs. 78 ± 13 bursts (100 beats)−1; P= 0.002). After aliskiren treatment, supine MSNA remained unchanged (69 ± 13 vs. 64 ± 8 bursts (100 beats)−1), but upright MSNA was lower (74 ± 15 vs. 85 ± 10 bursts (100 beats)−1; P= 0.012 for pre/post × posture). Direct renin was greater after both treatments (both P < 0.05), while upright aldosterone was greater after hydrochlorothiazide only (P= 0.002). The change in upright MSNA by the treatment was correlated with the change of aldosterone (r= 0.74, P= 0.002). Upright sympathetic BRS remained unchanged after either treatment. Thus, chronic renin inhibition may reduce upright MSNA through suppressed renin activity, while diuresis may evoke sympathetic activation via the upregulated renin–angiotensin–aldosterone system, without changing intrinsic sympathetic baroreflex function in elderly hypertensive

  1. Baroreflex dysfunction and augmented sympathetic nerve responses during mental stress in veterans with post-traumatic stress disorder.

    Science.gov (United States)

    Park, Jeanie; Marvar, Paul J; Liao, Peizhou; Kankam, Melanie L; Norrholm, Seth D; Downey, Ryan M; McCullough, S Ashley; Le, Ngoc-Anh; Rothbaum, Barbara O

    2017-07-15

    Patients with post-traumatic stress disorder (PTSD) are at a significantly higher risk of developing hypertension and cardiovascular disease. The mechanisms underlying this increased risk are not known. Studies have suggested that PTSD patients have an overactive sympathetic nervous system (SNS) that could contribute to cardiovascular risk; however, sympathetic function has not previously been rigorously evaluated in PTSD patients. Using direct measurements of sympathetic nerve activity and pharmacological manipulation of blood pressure, we show that veterans with PTSD have augmented SNS and haemodynamic reactivity during both combat-related and non-combat related mental stress, impaired sympathetic and cardiovagal baroreflex sensitivity, and increased inflammation. Identifying the mechanisms contributing to increased cardiovascular (CV) risk in PTSD will pave the way for developing interventions to improve sympathetic function and reduce CV risk in these patients. Post-traumatic stress disorder (PTSD) is associated with increased cardiovascular (CV) risk. We tested the hypothesis that PTSD patients have augmented sympathetic nervous system (SNS) and haemodynamic reactivity during mental stress, as well as impaired arterial baroreflex sensitivity (BRS). Fourteen otherwise healthy Veterans with combat-related PTSD were compared with 14 matched Controls without PTSD.  Muscle sympathetic nerve activity (MSNA), continuous blood pressure (BP) and electrocardiography were measured at baseline, as well as during two types of mental stress:  combat-related mental stress using virtual reality combat exposure (VRCE) and non-combat related stress using mental arithmetic (MA). A cold pressor test (CPT) was administered for comparison. BRS was tested using pharmacological manipulation of BP via the Modified Oxford technique at rest and during VRCE. Blood samples were analysed for inflammatory biomarkers. Baseline characteristics, MSNA and haemodynamics were similar between

  2. Optic Nerve Imaging

    Science.gov (United States)

    ... News About Us Donate In This Section Optic Nerve Imaging email Send this article to a friend ... measurements of nerve fiber damage (or loss). The Nerve Fiber Analyzer (GDx) uses laser light to measure ...

  3. Sympathetic Innervation Promotes Arterial Fate by Enhancing Endothelial ERK Activity.

    Science.gov (United States)

    Pardanaud, Luc; Pibouin-Fragner, Laurence; Dubrac, Alexandre; Mathivet, Thomas; English, Isabel; Brunet, Isabelle; Simons, Michael; Eichmann, Anne

    2016-08-19

    Arterial endothelial cells are morphologically, functionally, and molecularly distinct from those found in veins and lymphatic vessels. How arterial fate is acquired during development and maintained in adult vessels is incompletely understood. We set out to identify factors that promote arterial endothelial cell fate in vivo. We developed a functional assay, allowing us to monitor and manipulate arterial fate in vivo, using arteries isolated from quails that are grafted into the coelom of chick embryos. Endothelial cells migrate out from the grafted artery, and their colonization of host arteries and veins is quantified. Here we show that sympathetic innervation promotes arterial endothelial cell fate in vivo. Removal of sympathetic nerves decreases arterial fate and leads to colonization of veins, whereas exposure to sympathetic nerves or norepinephrine imposes arterial fate. Mechanistically, sympathetic nerves increase endothelial ERK (extracellular signal-regulated kinase) activity via adrenergic α1 and α2 receptors. These findings show that sympathetic innervation promotes arterial endothelial fate and may lead to novel approaches to improve arterialization in human disease. © 2016 American Heart Association, Inc.

  4. Effects of acute administration of selective serotonin reuptake inhibitors on sympathetic nerve activity

    International Nuclear Information System (INIS)

    Tiradentes, R.V.; Pires, J.G.P.; Silva, N.F.; Ramage, A.G.; Santuzzi, C.H.; Futuro, H.A. Neto

    2014-01-01

    Serotonergic mechanisms have an important function in the central control of circulation. Here, the acute effects of three selective serotonin (5-HT) reuptake inhibitors (SSRIs) on autonomic and cardiorespiratory variables were measured in rats. Although SSRIs require 2-3 weeks to achieve their full antidepressant effects, it has been shown that they cause an immediate inhibition of 5-HT reuptake. Seventy male Wistar rats were anesthetized with urethane and instrumented to record blood pressure, heart rate, renal sympathetic nerve activity (RSNA), and respiratory frequency. At lower doses, the acute cardiovascular effects of fluoxetine, paroxetine and sertraline administered intravenously were insignificant and variable. At middle and higher doses, a general pattern was observed, with significant reductions in sympathetic nerve activity. At 10 min, fluoxetine (3 and 10 mg/kg) reduced RSNA by -33±4.7 and -31±5.4%, respectively, without changes in blood pressure; 3 and 10 mg/kg paroxetine reduced RSNA by -35±5.4 and -31±5.5%, respectively, with an increase in blood pressure +26.3±2.5; 3 mg/kg sertraline reduced RSNA by -59.4±8.6%, without changes in blood pressure. Sympathoinhibition began 5 min after injection and lasted approximately 30 min. For fluoxetine and sertraline, but not paroxetine, there was a reduction in heart rate that was nearly parallel to the sympathoinhibition. The effect of these drugs on the other variables was insignificant. In conclusion, acute peripheral administration of SSRIs caused early autonomic cardiovascular effects, particularly sympathoinhibition, as measured by RSNA. Although a peripheral action cannot be ruled out, such effects are presumably mostly central

  5. Effects of acute administration of selective serotonin reuptake inhibitors on sympathetic nerve activity

    Energy Technology Data Exchange (ETDEWEB)

    Tiradentes, R.V. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Pires, J.G.P. [Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Escola de Medicina da Empresa Brasileira de Ensino, Vitória, ES (Brazil); Silva, N.F. [Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Ramage, A.G. [Department of Neuroscience, Physiology and Pharmacology, University College London, London (United Kingdom); Santuzzi, C.H. [Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Centro Universitário do Espírito Santo, Colatina, ES (Brazil); Futuro, H.A. Neto [Escola de Medicina da Empresa Brasileira de Ensino, Vitória, ES (Brazil); Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Escola Superior de Ciências da Saúde, Santa Casa de Misericórdia de Vitória, Vitória, ES (Brazil)

    2014-05-30

    Serotonergic mechanisms have an important function in the central control of circulation. Here, the acute effects of three selective serotonin (5-HT) reuptake inhibitors (SSRIs) on autonomic and cardiorespiratory variables were measured in rats. Although SSRIs require 2-3 weeks to achieve their full antidepressant effects, it has been shown that they cause an immediate inhibition of 5-HT reuptake. Seventy male Wistar rats were anesthetized with urethane and instrumented to record blood pressure, heart rate, renal sympathetic nerve activity (RSNA), and respiratory frequency. At lower doses, the acute cardiovascular effects of fluoxetine, paroxetine and sertraline administered intravenously were insignificant and variable. At middle and higher doses, a general pattern was observed, with significant reductions in sympathetic nerve activity. At 10 min, fluoxetine (3 and 10 mg/kg) reduced RSNA by -33±4.7 and -31±5.4%, respectively, without changes in blood pressure; 3 and 10 mg/kg paroxetine reduced RSNA by -35±5.4 and -31±5.5%, respectively, with an increase in blood pressure +26.3±2.5; 3 mg/kg sertraline reduced RSNA by -59.4±8.6%, without changes in blood pressure. Sympathoinhibition began 5 min after injection and lasted approximately 30 min. For fluoxetine and sertraline, but not paroxetine, there was a reduction in heart rate that was nearly parallel to the sympathoinhibition. The effect of these drugs on the other variables was insignificant. In conclusion, acute peripheral administration of SSRIs caused early autonomic cardiovascular effects, particularly sympathoinhibition, as measured by RSNA. Although a peripheral action cannot be ruled out, such effects are presumably mostly central.

  6. Sex steroids, insulin sensitivity and sympathetic nerve activity in relation to affective symptoms in women with polycystic ovary syndrome.

    Science.gov (United States)

    Jedel, Elizabeth; Gustafson, Deborah; Waern, Margda; Sverrisdottir, Yrsa Bergmann; Landén, Mikael; Janson, Per Olof; Labrie, Fernand; Ohlsson, Claes; Stener-Victorin, Elisabet

    2011-11-01

    Affective symptoms are poorly understood in polycystic ovary syndrome (PCOS). Clinical signs of hyperandrogenism and high serum androgens are key features in PCOS, and women with PCOS are more likely to be overweight or obese, as well as insulin resistant. Further, PCOS is associated with high sympathetic nerve activity. To elucidate if self-reported hirsutism, body mass index (BMI) and waistline, circulating sex steroids, sex hormone-binding globulin (SHBG), insulin sensitivity and sympathetic nerve activity are associated with depression and anxiety-related symptoms in women with PCOS. Seventy-two women with PCOS, aged 21-37 years, were recruited from the community. Hirsutism was self-reported using the Ferriman-Gallway score. Serum estrogens, sex steroid precursors, androgens and glucuronidated androgen metabolites were analyzed by gas and liquid chromatography/mass spectroscopy (GC-MS/LC-MS/MS) and SHBG by chemiluminiscent microparticle immunoassay (CMIA). Insulin sensitivity was measured with euglycemic hyperinsulinemic clamp. Sympathetic nerve activity was measured with microneurography. Symptoms of depression and anxiety were self-reported using the Montgomery Åsberg Depression Rating Scale (MADRS-S) and the Brief Scale for Anxiety (BSA-S). Circulating concentrations of testosterone (T) (P=0.026), free T (FT) (P=0.025), and androstane-3α 17β-diol-3glucuronide (3G) (P=0.029) were lower in women with depression symptoms of potential clinical relevance (MADR-S≥11). The odds of having a MADRS-S score ≥11 were higher with lower FT and 3G. No associations with BSA-S were noted. Lower circulating FT and 3G were associated with worse self-reported depression symptoms. The relationship between mental health, sex steroids and corresponding metabolites in PCOS requires further investigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Sympathetic chain Schwannoma

    International Nuclear Information System (INIS)

    Al-Mashat, Faisal M.

    2009-01-01

    Schwannomas are rare, benign, slowly growing tumors arising from Schwann cells that line nerve sheaths. Schwannomas arising from the cervical sympathetic chain are extremely rare. Here, we report a case of a 70-year-old man who presented with only an asymptomatic neck mass. Physical examination revealed a left sided Horner syndrome and a neck mass with transmitted pulsation and anterior displacement of the carotid artery. Computed tomography (CT) showed a well-defined non-enhancing mass with vascular displacement. The nerve of origin of this encapsulated tumor was the sympathetic chain. The tumor was excised completely intact. The pathologic diagnosis was Schwannoma (Antoni type A and Antoni type B). The patient has been well and free of tumor recurrence for 14 months with persistence of asymptomatic left sided Horner syndrome. The clinical, radiological and pathological evaluations, therapy and postoperative complications of this tumor are discussed. (author)

  8. Exposure to a high-fat diet alters leptin sensitivity and elevates renal sympathetic nerve activity and arterial pressure in rabbits.

    Science.gov (United States)

    Prior, Larissa J; Eikelis, Nina; Armitage, James A; Davern, Pamela J; Burke, Sandra L; Montani, Jean-Pierre; Barzel, Benjamin; Head, Geoffrey A

    2010-04-01

    The activation of the sympathetic nervous system through the central actions of the adipokine leptin has been suggested as a major mechanism by which obesity contributes to the development of hypertension. However, direct evidence for elevated sympathetic activity in obesity has been limited to muscle. The present study examined the renal sympathetic nerve activity and cardiovascular effects of a high-fat diet (HFD), as well as the changes in the sensitivity to intracerebroventricular leptin. New Zealand white rabbits fed a 13.5% HFD for 4 weeks showed modest weight gain but a 2- to 3-fold greater accumulation of visceral fat compared with control rabbits. Mean arterial pressure, heart rate, and plasma norepinephrine concentration increased by 8%, 26%, and 87%, respectively (Pdiet rabbits and was correlated to plasma leptin (r=0.87; Pfat accumulation through consumption of a HFD leads to marked sympathetic activation, which is related to increased responsiveness to central sympathoexcitatory effects of leptin. The paradoxical reduction in hypothalamic neuronal activation by leptin suggests a marked "selective leptin resistance" in these animals.

  9. Influence of ventilation and hypocapnia on sympathetic nerve responses to hypoxia in normal humans.

    Science.gov (United States)

    Somers, V K; Mark, A L; Zavala, D C; Abboud, F M

    1989-11-01

    The sympathetic response to hypoxia depends on the interaction between chemoreceptor stimulation (CRS) and the associated hyperventilation. We studied this interaction by measuring sympathetic nerve activity (SNA) to muscle in 13 normal subjects, while breathing room air, 14% O2, 10% O2, and 10% O2 with added CO2 to maintain isocapnia. Minute ventilation (VE) and blood pressure (BP) increased significantly more during isocapnic hypoxia (IHO) than hypocapnic hypoxia (HHO). In contrast, SNA increased more during HHO [40 +/- 10% (SE)] than during IHO (25 +/- 19%, P less than 0.05). To determine the reason for the lesser increase in SNA with IHO, 11 subjects underwent voluntary apnea during HHO and IHO. Apnea potentiated the SNA responses to IHO more than to HHO. SNA responses to IHO were 17 +/- 7% during breathing and 173 +/- 47% during apnea whereas SNA responses to HHO were 35 +/- 8% during breathing and 126 +/- 28% during apnea. During ventilation, the sympathoexcitation of IHO (compared with HHO) is suppressed, possibly for two reasons: 1) because of the inhibitory influence of activation of pulmonary afferents as a result of a greater increase in VE, and 2) because of the inhibitory influence of baroreceptor activation due to a greater rise in BP. Thus in humans, the ventilatory response to chemoreceptor stimulation predominates and restrains the sympathetic response. The SNA response to chemoreceptor stimulation represents the net effect of the excitatory influence of the chemoreflex and the inhibitory influence of pulmonary afferents and baroreceptor afferents.

  10. Resting sympathetic activity is associated with the sympathetically mediated component of energy expenditure following a meal.

    Science.gov (United States)

    Limberg, Jacqueline K; Malterer, Katherine R; Matzek, Luke J; Levine, James A; Charkoudian, Nisha; Miles, John M; Joyner, Michael J; Curry, Timothy B

    2017-08-01

    Individuals with high plasma norepinephrine (NE) levels at rest have a smaller reduction in resting energy expenditure (REE) following β -adrenergic blockade. If this finding extends to the response to a meal, it could have important implications for the role of the sympathetic nervous system in energy balance and weight gain. We hypothesized high muscle sympathetic nerve activity (MSNA) would be associated with a low sympathetically mediated component of energy expenditure following a meal. Fourteen young, healthy adults completed two visits randomized to continuous saline (control) or intravenous propranolol to achieve systemic β -adrenergic blockade. Muscle sympathetic nerve activity and REE were measured (indirect calorimetry) followed by a liquid mixed meal (Ensure). Measures of energy expenditure continued every 30 min for 5 h after the meal and are reported as an area under the curve (AUC). Sympathetic support of energy expenditure was calculated as the difference between the AUC during saline and β -blockade (AUC P ropranolol -AUC S aline , β -REE) and as a percent (%) of control (AUC P ropranolol ÷AUC S aline  × 100). β -REE was associated with baseline sympathetic activity, such that individuals with high resting MSNA (bursts/100 heart beats) and plasma NE had the greatest sympathetically mediated component of energy expenditure following a meal (MSNA: β -REE R  =   -0.58, P =  0.03; %REE R  = -0.56, P =  0.04; NE: β -REE R  = -0.55, P  = 0.0535; %REE R  = -0.54, P  = 0.0552). Contrary to our hypothesis, high resting sympathetic activity is associated with a greater sympathetically mediated component of energy expenditure following a liquid meal. These findings may have implications for weight maintenance in individuals with varying resting sympathetic activity. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  11. Defective propagation of signals generated by sympathetic nerve stimulation in the liver of connexin32-deficient mice.

    OpenAIRE

    Nelles, E; Bützler, C; Jung, D; Temme, A; Gabriel, H D; Dahl, U; Traub, O; Stümpel, F; Jungermann, K; Zielasek, J; Toyka, K V; Dermietzel, R; Willecke, K

    1996-01-01

    The gap junctional protein connexin32 is expressed in hepatocytes, exocrine pancreatic cells, Schwann cells, and other cell types. We have inactivated the connexin32 gene by homologous recombination in the mouse genome and have generated homozygous connexin32-deficient mice that were viable and fertile but weighed on the average approximately 17% less than wild-type controls. Electrical stimulation of sympathetic nerves in connexin32-deficient liver triggered a 78% lower amount of glucose mob...

  12. The sympathetic innervation of the heart: Important new insights.

    Science.gov (United States)

    Coote, J H; Chauhan, R A

    2016-08-01

    Autonomic control of the heart has a significant influence over development of life threatening arrhythmias that can lead to sudden cardiac death. Sympathetic activity is known to be upregulated during these conditions and hence the sympathetic nerves present a target for treatment. However, a better understanding of the anatomy and physiology of cardiac sympathetic nerves is required for the progression of clinical interventions. This review explores the organization of the cardiac sympathetic nerves, from the preganglionic origin to the postganglionic innervations, and provides an overview of literature surrounding anti-arrhythmic therapies including thoracic sympathectomy and dorsal spinal cord stimulation. Several features of the innervation are clear. The cardiac nerves differentially supply the nodal and myocardial tissue of the heart and are dependent on activity generated in spinal neurones in the upper thoracic cord which project to synapse with ganglion cells in the stellate complex on each side. Networks of spinal interneurones determine the pattern of activity. Groups of spinal neurones selectively target specific regions of the heart but whether they exhibit a functional selectivity has still to be elucidated. Electrical or ischemic signals can lead to remodeling of nerves in the heart or ganglia. Surgical and electrical methods are proving to be clinically beneficial in reducing atrial and ventricular arrhythmias, heart failure and severe cardiac pain. This is a rapidly developing area and we need more basic understanding of how these methods work to ensure safety and reduction of side effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Imaging the ocular motor nerves

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Teresa [Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: T.A.Ferreira@lumc.nl; Verbist, Berit [Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: B.M.Verbist@lumc.nl; Buchem, Mark van [Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: M.A.van_Buchem@lumc.nl; Osch, Thijs van [C.J. Gorter for High-Field MRI, Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: M.J.P.van_Osch@lumc.nl; Webb, Andrew [C.J. Gorter for High-Field MRI, Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: A.Webb@lumc.nl

    2010-05-15

    The ocular motor nerves (OMNs) comprise the oculomotor, trochlear and the abducens nerves. According to their course, they are divided into four or five anatomic segments: intra-axial, cisternal, cavernous and intra-orbital and, for the abducens nerve, an additional interdural segment. Magnetic resonance imaging is the imaging method of choice in the evaluation of the normal and pathologic ocular motor nerves. CT still plays a limited but important role in the evaluation of the intraosseous portions at the skull base and bony foramina. We describe for each segment of these cranial nerves, the normal anatomy, the most appropriate image sequences and planes, their imaging appearance and pathologic conditions. Magnetic resonance imaging with high magnetic fields is a developing and promising technique. We describe our initial experience with a Phillips 7.0 T MRI scanner in the evaluation of the brainstem segments of the OMNs. As imaging becomes more refined, an understanding of the detailed anatomy is increasingly necessary, as the demand on radiology to diagnose smaller lesions also increases.

  14. Increase in Operator's Sympathetic Nerve Activity during Complicated Hepatobiliary Surgery: Evidence for Surgeons' Mental Stress.

    Science.gov (United States)

    Yamanouchi, Kosho; Hayashida, Naomi; Kuba, Sayaka; Sakimura, Chika; Kuroki, Tamotsu; Togo, Michita; Katayama, Noritada; Takamura, Noboru; Eguchi, Susumu

    2015-11-01

    Surgeons often experience stress during operations. The heart rate variability (HRV) is the variability in the beat-to-beat interval, which has been used as parameters of stress. The purpose of this study was to evaluate mental stress of surgeons before, during and after operations, especially during pancreaticoduodenectomy (PD) and living donor liver transplantation (LDLT). Additionally, the parameters were compared in various procedures during the operations. By frequency domain method using electrocardiograph, we measured the high frequency (HF) component, representing the parasympathetic activity, and the low frequency (LF)/HF ratio, representing the sympathetic activity. In all 5 cases of PD, the surgeon showed significantly lower HF component and higher LF/HF during operation, indicating predominance of sympathetic nervous system and increased stress, than those before the operation (p operation. Out of the 4 LDLT cases, the value of HF was decreased in two and the LF/HF increased in three cases (p operation compared to those before the operation. In all cases, the value of HF was decreased and/or the LF/HF increased significantly during the reconstruction of the vessels or bile ducts than during the removal of the liver. Thus, sympathetic nerve activity increased during hepatobiliary surgery compared with the level before the operation, and various procedures during the operations induced diverse changes in the autonomic nervous activities. The HRV analysis could assess the chronological changes of mental stress by measuring the autonomic nervous balances.

  15. Role of renal sympathetic nerve activity in prenatal programming of hypertension.

    Science.gov (United States)

    Baum, Michel

    2018-03-01

    Prenatal insults, such as maternal dietary protein deprivation and uteroplacental insufficiency, lead to small for gestational age (SGA) neonates. Epidemiological studies from many different parts of the world have shown that SGA neonates are at increased risk for hypertension and early death from cardiovascular disease as adults. Animal models, including prenatal administration of dexamethasone, uterine artery ligation and maternal dietary protein restriction, result in SGA neonates with fewer nephrons than controls. These models are discussed in this educational review, which provides evidence that prenatal insults lead to altered sodium transport in multiple nephron segments. The factors that could result in increased sodium transport are discussed, focusing on new information that there is increased renal sympathetic nerve activity that may be responsible for augmented renal tubular sodium transport. Renal denervation abrogates the hypertension in programmed rats but has no effect on control rats. Other potential factors that could cause hypertension in programmed rats, such as the renin-angiotensin system, are also discussed.

  16. Magnetic resonance imaging of optic nerve

    International Nuclear Information System (INIS)

    Gala, Foram

    2015-01-01

    Optic nerves are the second pair of cranial nerves and are unique as they represent an extension of the central nervous system. Apart from clinical and ophthalmoscopic evaluation, imaging, especially magnetic resonance imaging (MRI), plays an important role in the complete evaluation of optic nerve and the entire visual pathway. In this pictorial essay, the authors describe segmental anatomy of the optic nerve and review the imaging findings of various conditions affecting the optic nerves. MRI allows excellent depiction of the intricate anatomy of optic nerves due to its excellent soft tissue contrast without exposure to ionizing radiation, better delineation of the entire visual pathway, and accurate evaluation of associated intracranial pathologies

  17. Losartan reduces the immediate and sustained increases in muscle sympathetic nerve activity after hyperacute intermittent hypoxia.

    Science.gov (United States)

    Jouett, Noah P; Moralez, Gilbert; Raven, Peter B; Smith, Michael L

    2017-04-01

    Obstructive sleep apnea (OSA) is characterized by intermittent hypoxemia, which produces elevations in sympathetic nerve activity (SNA) and associated hypertension in experimental models that persist beyond the initial exposure. We tested the hypotheses that angiotensin receptor blockade in humans using losartan attenuates the immediate and immediately persistent increases in 1 ) SNA discharge and 2 ) mean arterial pressure (MAP) after hyperacute intermittent hypoxia training (IHT) using a randomized, placebo-controlled, repeated-measures experimental design. We measured ECG and photoplethysmographic arterial pressure in nine healthy human subjects, while muscle SNA (MSNA) was recorded in seven subjects using microneurography. Subjects were exposed to a series of hypoxic apneas in which they inhaled two to three breaths of nitrogen, followed by a 20-s apnea and 40 s of room air breathing every minute for 20 min. Hyperacute IHT produced substantial and persistent elevations in MSNA burst frequency (baseline: 15.3 ± 1.8, IHT: 24 ± 1.5, post-IHT 20.0 ± 1.3 bursts/min, all P 0.70). This investigation confirms the role of angiotensin II type 1a receptors in the immediate and persistent sympathoexcitatory and pressor responses to IHT. NEW & NOTEWORTHY This study demonstrates for the first time in humans that losartan, an angiotensin receptor blocker (ARB), abrogates the acute and immediately persistent increases in muscle sympathetic nerve activity and arterial pressure in response to acute intermittent hypoxia. This investigation, along with others, provides important beginning translational evidence for using ARBs in treatment of the intermittent hypoxia observed in obstructive sleep apnea patients. Copyright © 2017 the American Physiological Society.

  18. Netrin-1 controls sympathetic arterial innervation.

    Science.gov (United States)

    Brunet, Isabelle; Gordon, Emma; Han, Jinah; Cristofaro, Brunella; Broqueres-You, Dong; Liu, Chun; Bouvrée, Karine; Zhang, Jiasheng; del Toro, Raquel; Mathivet, Thomas; Larrivée, Bruno; Jagu, Julia; Pibouin-Fragner, Laurence; Pardanaud, Luc; Machado, Maria J C; Kennedy, Timothy E; Zhuang, Zhen; Simons, Michael; Levy, Bernard I; Tessier-Lavigne, Marc; Grenz, Almut; Eltzschig, Holger; Eichmann, Anne

    2014-07-01

    Autonomic sympathetic nerves innervate peripheral resistance arteries, thereby regulating vascular tone and controlling blood supply to organs. Despite the fundamental importance of blood flow control, how sympathetic arterial innervation develops remains largely unknown. Here, we identified the axon guidance cue netrin-1 as an essential factor required for development of arterial innervation in mice. Netrin-1 was produced by arterial smooth muscle cells (SMCs) at the onset of innervation, and arterial innervation required the interaction of netrin-1 with its receptor, deleted in colorectal cancer (DCC), on sympathetic growth cones. Function-blocking approaches, including cell type-specific deletion of the genes encoding Ntn1 in SMCs and Dcc in sympathetic neurons, led to severe and selective reduction of sympathetic innervation and to defective vasoconstriction in resistance arteries. These findings indicate that netrin-1 and DCC are critical for the control of arterial innervation and blood flow regulation in peripheral organs.

  19. MR imaging of cranial nerve schwannomas

    International Nuclear Information System (INIS)

    Shapiro, M.; Peyster, R.; Cross, R.R.; Charles, J.; Murtagh, R.; Shapiro, R.; Chyatte, D.

    1988-01-01

    One of the major advantages of magnetic resonance (MR) imaging over other imaging modalities is direct visualization of the cranial nerves. This is best accomplished with thin-section, contiguous T1-weighted images. They report a series of 75 cranial nerve neuromas, including 47 of the eighth nerve and a mixture of schwannomas involving all other cranial nerves (excluding the fourth). All tumors demonstrated at least some area of increased signal (equal to or greater than that of cerebrospinal fluid) on T2-weighted images. This fact enabled them to differentiate schwannomas from neoplasms (lymphoma, meningioma, sarcoma) that may be isointense on T2-weighted pulse sequences. Many of the lesions had areas of low signal intermixed with predominantly high signal (on T2-weighted images). The pathologic evaluation of these areas of decreased signal revealed predominant fibrosis. In addition, some of the neuromas had a cystic component. Gadolinium-enhanced MR imaging may permit detection when the nerve is still normal in size

  20. [Imaging anatomy of cranial nerves].

    Science.gov (United States)

    Hermier, M; Leal, P R L; Salaris, S F; Froment, J-C; Sindou, M

    2009-04-01

    Knowledge of the anatomy of the cranial nerves is mandatory for optimal radiological exploration and interpretation of the images in normal and pathological conditions. CT is the method of choice for the study of the skull base and its foramina. MRI explores the cranial nerves and their vascular relationships precisely. Because of their small size, it is essential to obtain images with high spatial resolution. The MRI sequences optimize contrast between nerves and surrounding structures (cerebrospinal fluid, fat, bone structures and vessels). This chapter discusses the radiological anatomy of the cranial nerves.

  1. Morphologic Changes in Autonomic Nerves in Diabetic Autonomic Neuropathy

    Directory of Open Access Journals (Sweden)

    Heung Yong Jin

    2015-12-01

    Full Text Available Diabetic neuropathy is one of the major complications of diabetes, and it increases morbidity and mortality in patients with both type 1 diabetes mellitus (T1DM and type 2 diabetes mellitus (T2DM. Because the autonomic nervous system, for example, parasympathetic axons, has a diffuse and wide distribution, we do not know the morphological changes that occur in autonomic neural control and their exact mechanisms in diabetic patients with diabetic autonomic neuropathy (DAN. Although the prevalence of sympathetic and parasympathetic neuropathy is similar in T1DM versus T2DM patients, sympathetic nerve function correlates with parasympathetic neuropathy only in T1DM patients. The explanation for these discrepancies might be that parasympathetic nerve function was more severely affected among T2DM patients. As parasympathetic nerve damage seems to be more advanced than sympathetic nerve damage, it might be that parasympathetic neuropathy precedes sympathetic neuropathy in T2DM, which was Ewing's concept. This could be explained by the intrinsic morphologic difference. Therefore, the morphological changes in the sympathetic and parasympathetic nerves of involved organs in T1DM and T2DM patients who have DAN should be evaluated. In this review, evaluation methods for morphological changes in the epidermal nerves of skin, and the intrinsic nerves of the stomach will be discussed.

  2. Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension.

    Science.gov (United States)

    Sata, Yusuke; Head, Geoffrey A; Denton, Kate; May, Clive N; Schlaich, Markus P

    2018-01-01

    The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA) is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target.

  3. Effect of amine uptake inhibitors on the uptake of 14C-bretylium in intact and degenerating sympathetic nerves of the rat

    International Nuclear Information System (INIS)

    Almgren, O.

    1981-01-01

    The effect of different amine uptake inhibitors on the accumulation of 14 C-bretylium in sympathetically denervated or decentralized salivary glands were studied in vivo in rats 11-14 hours after the surgical intervention. The time period chosen is known to be critical for the delaying effect of bretylium on the degeneration transmitter release in sympathetically innervated organs. Cocaine, desmethylimipramine (DMI), protriptyline or reserpine all depressed the uptake of 14 C-bretylium in both denervated and decentralized salivary glands, cocaine being the most efficient one. DMI and protriptyline, but not cocaine inhibit the degeneration delaying effect of bretylium, while all three agents inhibit amine uptake at level of the nerve cell membrane. Apparently, bretylium reaches the critical sites of its degeneration delaying action by the axonal amine pump but only a small fraction of the drug entering the degenerating adrenergic nerve terminal is needed at the critical sites to interact with the degeneration processes. The difference between the tricyclic antidepressants on one hand and cocaine on the other with respect to the effect on the degeneration delaying action of bretylium, must depend on some action different from the axonal membrane uptake inhibition. Reserpine which is known not to interfere with the delaying effect of bretylium on the denervation degeneration did reduce the uptake of 14 C-bretylium. This fact seems to indicate that the site of action of bretylium is located outside the adrenergic nerve granules. (author)

  4. Cardiac sympathetic neuronal imaging using PET

    International Nuclear Information System (INIS)

    Lautamaeki, Riikka; Tipre, Dnyanesh; Bengel, Frank M.

    2007-01-01

    Balance of the autonomic nervous system is essential for adequate cardiac performance, and alterations seem to play a key role in the development and progression of various cardiac diseases. PET imaging of the cardiac autonomic nervous system has advanced extensively in recent years, and multiple pre- and postsynaptic tracers have been introduced. The high spatial and temporal resolution of PET enables noninvasive quantification of neurophysiologic processes at the tissue level. Ligands for catecholamine receptors, along with radiolabeled catecholamines and catecholamine analogs, have been applied to determine involvement of sympathetic dysinnervation at different stages of heart diseases such as ischemia, heart failure, and arrhythmia. This review summarizes the recent findings in neurocardiological PET imaging. Experimental studies with several radioligands and clinical findings in cardiac dysautonomias are discussed. (orig.)

  5. MR imaging of the intraparotid facial nerve

    International Nuclear Information System (INIS)

    Kurihara, Hiroaki; Iwasawa, Tae; Yoshida, Tetsuo; Furukawa, Masaki

    1996-01-01

    Using a 1.5T MR imaging system, seven normal volunteers and 6 patients with parotid tumors were studied and their intraparotid facial nerves were directly imaged. The findings were evaluated by T1-weighted axial, sagittal and oblique images. The facial nerve appeared to be relatively hypointensive within the highsignal parotid parenchyma, and the main trunks of the facial nerves were observed directly in all the cases examined. Their main divisions were detected in all the volunteers and 5 of 6 patients were imaged obliquely. The facial nerves run in various fashions and so the oblique scan planes were determined individually to detect this running figure directly. To verify our observations, surgical findings of the facial nerve were compared with the MR images or results. (author)

  6. The sympathetic nervous system in polycystic ovary syndrome: a novel therapeutic target?

    Science.gov (United States)

    Lansdown, Andrew; Rees, D Aled

    2012-12-01

    Polycystic ovary syndrome (PCOS) is a common endocrine condition associated with long-term health risks, including type 2 diabetes and vascular dysfunction in addition to reproductive sequelae. Many of the common features of PCOS, such as central obesity, hyperinsulinaemia and obstructive sleep apnoea (OSA), are associated with chronic sympathetic overactivity, suggesting that sympathoexcitation may be involved in the pathogenesis of this condition. Rodent models of polycystic ovaries have shown that ovarian sympathetic outflow may be increased, accompanied by elevated intra-ovarian synthesis of nerve growth factor (NGF) which may be involved in initiation of ovarian pathology. Patients with PCOS have evidence of increased muscle sympathetic nerve activity (MSNA), altered heart rate variability and attenuated heart rate recovery postexercise, compared with age- and BMI-matched controls, suggesting a generalized increase in sympathetic nerve activity. Active weight loss can reduce MSNA and whole body noradrenaline spillover, whereas low-frequency electroacupuncture decreased MSNA in overweight women with PCOS. Treatment of OSA with continuous positive airways pressure may reduce plasma noradrenaline levels and diastolic blood pressure and improve cardiac sympathovagal balance. Renal sympathetic denervation also reduced MSNA, noradrenaline spillover and blood pressure in two PCOS subjects with hypertension, accompanied by improved insulin sensitivity. The sympathetic nervous system may thus offer a new therapeutic target in PCOS but larger and longer-term studies are needed before these treatments can be considered in clinical practice. © 2012 Blackwell Publishing Ltd.

  7. Micro-anatomy of the renal sympathetic nervous system: a human postmortem histologic study.

    Science.gov (United States)

    Atherton, Daniel S; Deep, Nicholas L; Mendelsohn, Farrell O

    2012-07-01

    Hypertension remains an epidemic uncontrolled with pharmacologic therapies. A novel catheter inserted into the renal artery has been shown to lower blood pressure by ablating the renal sympathetic nerves with radiofrequency energy delivered through the arterial wall. We report a histologic study describing the anatomic substrate for this technique, specifically the renal sympathetic nervous system. Histological sections from proximal, middle, and distal renal artery segments from nine renal arteries (five human autopsies) were analyzed. Nerves were manually counted and their distance from the lumen-intima interface was measured using a micrometer. The nerves were then categorized by location into 0.5-mm-wide "rings" that were arranged circumferentially around the renal artery lumen. Of all nerves detected, 1.0% was in the 0-0.5 mm ring, 48.3% were in the 0.5-1.0 mm ring, 25.6% were in the 1.0-1.5 mm ring, 15.5% were in the 1.5-2.0 mm ring, and 9.5% were in the 2.0-2.5 mm ring. Beyond 0.5 mm, the proportion of nerves tended to decrease as the distance from the lumen increased. Totally, 90.5% of all nerves in this study existed within 2.0 mm of the renal artery lumen. Additionally, the number of nerves tended to increase along the length of the artery from proximal to distal segments (proximal = 216; middle = 323; distal = 417). In conclusion, our analysis indicates that a great proportion of renal sympathetic nerves have close proximity to the lumen-intima interface and should thus be accessible via renal artery interventional approaches such as catheter ablation. This data provides important anatomic information for the development of ablation and other type devices for renal sympathetic denervation. © 2011 Wiley Periodicals, Inc.

  8. Vestibular control of sympathetic activity. An otolith-sympathetic reflex in humans.

    Science.gov (United States)

    Kaufmann, H; Biaggioni, I; Voustianiouk, A; Diedrich, A; Costa, F; Clarke, R; Gizzi, M; Raphan, T; Cohen, B

    2002-04-01

    It has been proposed that a vestibular reflex originating in the otolith organs and other body graviceptors modulates sympathetic activity during changes in posture with regard to gravity. To test this hypothesis, we selectively stimulated otolith and body graviceptors sinusoidally along different head axes in the coronal plane with off-vertical axis rotation (OVAR) and recorded sympathetic efferent activity in the peroneal nerve (muscle sympathetic nerve activity, MSNA), blood pressure, heart rate, and respiratory rate. All parameters were entrained during OVAR at the frequency of rotation, with MSNA increasing in nose-up positions during forward linear acceleration and decreasing when nose-down. MSNA was correlated closely with blood pressure when subjects were within +/-90 degrees of nose-down positions with a delay of 1.4 s, the normal latency of baroreflex-driven changes in MSNA. Thus, in the nose-down position, MSNA was probably driven by baroreflex afferents. In contrast, when subjects were within +/-45 degrees of the nose-up position, i.e., when positive linear acceleration was maximal along the naso-ocipital axis, MSNA was closely related to gravitational acceleration at a latency of 0.4 s. This delay is too short for MSNA changes to be mediated by the baroreflex, but it is compatible with the delay of a response originating in the vestibular system. We postulate that a vestibulosympathetic reflex, probably originating mainly in the otolith organs, contributes to blood pressure maintenance during forward linear acceleration. Because of its short latency, this reflex may be one of the earliest mechanisms to sustain blood pressure upon standing.

  9. Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension

    Directory of Open Access Journals (Sweden)

    Yusuke Sata

    2018-03-01

    Full Text Available The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target.

  10. Imaging the Facial Nerve: A Contemporary Review

    International Nuclear Information System (INIS)

    Gupta, S.; Roehm, P.C.; Mends, F.; Hagiwara, M.; Fatterpekar, G.

    2013-01-01

    Imaging plays a critical role in the evaluation of a number of facial nerve disorders. The facial nerve has a complex anatomical course; thus, a thorough understanding of the course of the facial nerve is essential to localize the sites of pathology. Facial nerve dysfunction can occur from a variety of causes, which can often be identified on imaging. Computed tomography and magnetic resonance imaging are helpful for identifying bony facial canal and soft tissue abnormalities, respectively. Ultrasound of the facial nerve has been used to predict functional outcomes in patients with Bell’s palsy. More recently, diffusion tensor tractography has appeared as a new modality which allows three-dimensional display of facial nerve fibers

  11. Reflex sympathetic dystrophy syndrome: MR imaging study

    International Nuclear Information System (INIS)

    Masciocchi, C.; Fascetti, E.; Bonanni, G.; Calvisi, V.; Buoni, C.; Passariello, R.

    1987-01-01

    Reflex sympathetic dystrophy syndrome (RSDS) is characterized by pain, swelling, and limitation of motion. The etiology and pathophysiology mechanism have not yet been identified. We considered eight patients with clinical signs of RSDS, in five cases located at the knee joint and in three cases in the hip. In all cases conventional radiography and radionuclide bone scanning were performed before MR imaging. Conventional radiography was negative in three cases while scintigraphy demonstrated the lesion in all patients. MR imaging showed an area of low intensity signal on T1-weighted scans and an increased signal intensity on T2-weighted images. This area is located at the bone marrow and its regular and homogeneous. This specific finding on MR images is due to reflect edema by hyperemia of the bone marrow. The MR imaging diagnosis was confirmed on clinical and radiological follow-up. MR imaging can have a role in the differential diagnosis when other studies are nondiagnostic or nonspecific for RSDS

  12. Imaging of the facial nerve

    Energy Technology Data Exchange (ETDEWEB)

    Veillon, F. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France)], E-mail: Francis.Veillon@chru-strasbourg.fr; Ramos-Taboada, L.; Abu-Eid, M. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France); Charpiot, A. [Service d' ORL, Hopital de Hautepierre, 67098 Strasbourg Cedex (France); Riehm, S. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France)

    2010-05-15

    The facial nerve is responsible for the motor innervation of the face. It has a visceral motor function (lacrimal, submandibular, sublingual glands and secretion of the nose); it conveys a great part of the taste fibers, participates to the general sensory of the auricle (skin of the concha) and the wall of the external auditory meatus. The facial mimic, production of tears, nasal flow and salivation all depend on the facial nerve. In order to image the facial nerve it is mandatory to be knowledgeable about its normal anatomy including the course of its efferent and afferent fibers and about relevant technical considerations regarding CT and MR to be able to achieve high-resolution images of the nerve.

  13. Cardiac sympathetic nervous system imaging with (123)I-meta-iodobenzylguanidine: Perspectives from Japan and Europe

    NARCIS (Netherlands)

    Nakajima, K.; Scholte, A.; Nakata, T.; Dimitriu-Leen, A.C.; Chikamori, T.; Vitola, J.V.; Yoshinaga, K.

    2017-01-01

    Cardiac sympathetic nervous system dysfunction is closely associated with risk of serious cardiac events in patients with heart failure (HF), including HF progression, pump-failure death, and sudden cardiac death by lethal ventricular arrhythmia. For cardiac sympathetic nervous system imaging,

  14. 1.5 T augmented reality navigated interventional MRI: paravertebral sympathetic plexus injections.

    Science.gov (United States)

    Marker, David R; U Thainual, Paweena; Ungi, Tamas; Flammang, Aaron J; Fichtinger, Gabor; Iordachita, Iulian I; Carrino, John A; Fritz, Jan

    2017-01-01

    The high contrast resolution and absent ionizing radiation of interventional magnetic resonance imaging (MRI) can be advantageous for paravertebral sympathetic nerve plexus injections. We assessed the feasibility and technical performance of MRI-guided paravertebral sympathetic injections utilizing augmented reality navigation and 1.5 T MRI scanner. A total of 23 bilateral injections of the thoracic (8/23, 35%), lumbar (8/23, 35%), and hypogastric (7/23, 30%) paravertebral sympathetic plexus were prospectively planned in twelve human cadavers using a 1.5 Tesla (T) MRI scanner and augmented reality navigation system. MRI-conditional needles were used. Gadolinium-DTPA-enhanced saline was injected. Outcome variables included the number of control magnetic resonance images, target error of the needle tip, punctures of critical nontarget structures, distribution of the injected fluid, and procedure length. Augmented-reality navigated MRI guidance at 1.5 T provided detailed anatomical visualization for successful targeting of the paravertebral space, needle placement, and perineural paravertebral injections in 46 of 46 targets (100%). A mean of 2 images (range, 1-5 images) were required to control needle placement. Changes of the needle trajectory occurred in 9 of 46 targets (20%) and changes of needle advancement occurred in 6 of 46 targets (13%), which were statistically not related to spinal regions (P = 0.728 and P = 0.86, respectively) and cadaver sizes (P = 0.893 and P = 0.859, respectively). The mean error of the needle tip was 3.9±1.7 mm. There were no punctures of critical nontarget structures. The mean procedure length was 33±12 min. 1.5 T augmented reality-navigated interventional MRI can provide accurate imaging guidance for perineural injections of the thoracic, lumbar, and hypogastric sympathetic plexus.

  15. Treatment of Reflex sympathetic dystrophy with Bee venom -Using Digital Infrared Thermographic Imaging-

    Directory of Open Access Journals (Sweden)

    Myung-jang Lim

    2006-12-01

    Full Text Available Objectives : The purpose of this case is to report the patient with Reflex sympathetic dystrophy, who is improved by Bee venom. Method : We treated the patient with Bee venom who was suffering from Reflex sympathetic dystrophy, using Digital Infrared Thermographic Imaging and Verbal Numerical Rating Scale(VNRS to evaluate the therapeutic effects. We compared the temperature of the patient body before and after treatment. Result and Conclusion : We found that Bee venom had excellent outcome to relieve pain, atrophy and ankle joint ROM, and that Bee venom also had clinical effect on hypothermia on the Digital Infrared Thermographic Imaging.

  16. Sympathetic rhythms and nervous integration.

    Science.gov (United States)

    Gilbey, Michael P

    2007-04-01

    1. The present review focuses on some of the processes producing rhythms in sympathetic nerves influencing cardiovascular functions and considers their potential relevance to nervous integration. 2. Two mechanisms are considered that may account for rhythmic sympathetic discharges. First, neuronal elements of peripheral or central origin produce rhythmic activity by phasically exciting and/or inhibiting neurons within central sympathetic networks. Second, rhythms arise within central sympathetic networks. Evidence is considered that indicates the operation of both mechanisms; the first in muscle and the second in skin sympathetic vasoconstrictor networks. 3. Sympathetic activity to the rat tail, a model for the nervous control of skin circulation, is regulated by central networks involved in thermoregulation and those associated with fear and arousal. In an anaesthetized preparation, activity displays an apparently autonomous rhythm (T-rhythm; 0.4-1.2 Hz) and the level of activity can be manipulated by regulating core body temperature. This model has been used to study rhythm generation in central sympathetic networks and possible functional relevance. 4. A unique insight provided by the T rhythm, into possible physiological function(s) underlying rhythmic sympathetic discharges is that the activity of single sympathetic post-ganglionic neurons within a population innervating the same target can have different rhythm frequencies. Therefore, the graded and dynamic entrainment of the rhythms by inputs, such as central respiratory drive and/or lung inflation-related afferent activity, can produce graded and dynamic synchronization of sympathetic discharges. The degree of synchronization may influence the efficacy of transmission in a target chain of excitable cells. 5. The T-rhythm may be generated within the spinal cord because the intrathecal application of 5-hydroxytryptamine at the L1 level of the spinal cord of a rat spinalized at T10-T11 produces a T-like rhythm

  17. Intracranial Pressure Is a Determinant of Sympathetic Activity

    Directory of Open Access Journals (Sweden)

    Eric A. Schmidt

    2018-02-01

    Full Text Available Intracranial pressure (ICP is the pressure within the cranium. ICP rise compresses brain vessels and reduces cerebral blood delivery. Massive ICP rise leads to cerebral ischemia, but it is also known to produce hypertension, bradycardia and respiratory irregularities due to a sympatho-adrenal mechanism termed Cushing response. One still unresolved question is whether the Cushing response is a non-synaptic acute brainstem ischemic mechanism or part of a larger physiological reflex for arterial blood pressure control and homeostasis regulation. We hypothesize that changes in ICP modulates sympathetic activity. Thus, modest ICP increase and decrease were achieved in mice and patients with respectively intra-ventricular and lumbar fluid infusion. Sympathetic activity was gauged directly by microneurography, recording renal sympathetic nerve activity in mice and muscle sympathetic nerve activity in patients, and gauged indirectly in both species by heart-rate variability analysis. In mice (n = 15, renal sympathetic activity increased from 29.9 ± 4.0 bursts.s−1 (baseline ICP 6.6 ± 0.7 mmHg to 45.7 ± 6.4 bursts.s−1 (plateau ICP 38.6 ± 1.0 mmHg and decreased to 34.8 ± 5.6 bursts.s−1 (post-infusion ICP 9.1 ± 0.8 mmHg. In patients (n = 10, muscle sympathetic activity increased from 51.2 ± 2.5 bursts.min−1 (baseline ICP 8.3 ± 1.0 mmHg to 66.7 ± 2.9 bursts.min−1 (plateau ICP 25 ± 0.3 mmHg and decreased to 58.8 ± 2.6 bursts.min−1 (post-infusion ICP 14.8 ± 0.9 mmHg. In patients 7 mmHg ICP rise significantly increases sympathetic activity by 17%. Heart-rate variability analysis demonstrated a significant vagal withdrawal during the ICP rise, in accordance with the microneurography findings. Mice and human results are alike. We demonstrate in animal and human that ICP is a reversible determinant of efferent sympathetic outflow, even at relatively low ICP levels. ICP is a biophysical stress related to the forces within the brain. But ICP

  18. The pedunculopontine tegmentum controls renal sympathetic nerve activity and cardiorespiratory activities in nembutal-anesthetized rats.

    Directory of Open Access Journals (Sweden)

    Anne M Fink

    Full Text Available Elevated renal sympathetic nerve activity (RSNA accompanies a variety of complex disorders, including obstructive sleep apnea, heart failure, and chronic kidney disease. Understanding pathophysiologic renal mechanisms is important for determining why hypertension is both a common sequelae and a predisposing factor of these disorders. The role of the brainstem in regulating RSNA remains incompletely understood. The pedunculopontine tegmentum (PPT is known for regulating behaviors including alertness, locomotion, and rapid eye movement sleep. Activation of PPT neurons in anesthetized rats was previously found to increase splanchnic sympathetic nerve activity and blood pressure, in addition to altering breathing. The present study is the first investigation of the PPT and its potential role in regulating RSNA. Microinjections of DL-homocysteic acid (DLH were used to probe the PPT in 100-μm increments in Nembutal-anesthetized rats to identify effective sites, defined as locations where changes in RSNA could be evoked. A total of 239 DLH microinjections were made in 18 rats, which identified 20 effective sites (each confirmed by the ability to evoke a repeatable sympathoexcitatory response. Peak increases in RSNA occurred within 10-20 seconds of PPT activation, with RSNA increasing by 104.5 ± 68.4% (mean ± standard deviation from baseline. Mean arterial pressure remained significantly elevated for 30 seconds, increasing from 101.6 ± 18.6 mmHg to 135.9 ± 36.4 mmHg. DLH microinjections also increased respiratory rate and minute ventilation. The effective sites were found throughout the rostal-caudal extent of the PPT with most located in the dorsal regions of the nucleus. The majority of PPT locations tested with DLH microinjections did not alter RSNA (179 sites, suggesting that the neurons that confer renal sympathoexcitatory functions comprise a small component of the PPT. The study also underscores the importance of further investigation to

  19. Imaging of the heart using metaiodobenzylguanidine

    International Nuclear Information System (INIS)

    Dae, M.W.; Botvinick, E.H.

    1990-01-01

    Catecholamines have profound influences on cardiac function. Mechanisms relating abnormalities in sympathetic innervation to myocardial dysfunction are poorly understood, however. Recent studies have demonstrated the feasibility of noninvasively imaging the sympathetic nerves of the heart using radiolabeled MIBG. This article examines some of the experimental evidence to support the neuronal localization of MIBG. In addition, the early clinical experience is reviewed.42 references

  20. Beneficial effect of perindopril on cardiac sympathetic nerve activity and brain natriuretic peptide in patients with chronic heart failure. Comparison with enalapril

    International Nuclear Information System (INIS)

    Tsutamoto, Takayoshi; Tanaka, Toshinari; Sakai, Hiroshi

    2008-01-01

    In patients with chronic heart failure (CHF), it remains unclear whether perindopril is more cardioprotective than enalapril. Forty-five stable CHF outpatients undergoing conventional therapy including enalapril therapy were randomized to 2 groups [group I (n=24): continuous enalapril treatment; group II (n=21): enalapril was changed to perindopril]. Cardiac sympathetic nerve activity was evaluated using cardiac 123 I-metaiodobenzylguanidine (MIBG) scintigraphy, hemodynamic parameters and neurohumoral factors before and 6 months after treatment. There was no difference in baseline characteristics between the 2 groups. In group I, there were no changes in MIBG parameters, left ventricular ejection fraction (LVEF) or plasma level of brain natriuretic peptide (BNP). In contrast, in group II delayed heart/mediastinum count ratio was significantly increased (2.0±0.07 vs 2.15±0.07, p=0.013) and the washout rate was significantly decreased (33.0±1.4 vs 30.5±1.2, p=0.030) after 6 months compared with the baseline value. In addition, LVEF was significantly increased and the plasma BNP level was significantly decreased. These findings suggest that for the treatment of CHF, perindopril is superior to enalapril with respect of cardiac sympathetic nerve activity and BNP. (author)

  1. Imaging of the optic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Minerva [Head and Neck and Maxillofacial Radiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland)], E-mail: minerva.becker@hcuge.ch; Masterson, Karen [Head and Neck and Maxillofacial Radiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Delavelle, Jacqueline [Neuroradiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Viallon, Magalie [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Vargas, Maria-Isabel [Neuroradiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Becker, Christoph D. [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland)

    2010-05-15

    This article provides an overview of the imaging findings of diseases affecting the optic nerve with special emphasis on clinical-radiological correlation and on the latest technical developments in MR imaging and CT. The review deals with congenital malformations, tumors, toxic/nutritional and degenerative entities, inflammatory and infectious diseases, compressive neuropathy, vascular conditions and trauma involving the optic nerve from its ocular segment to the chiasm. The implications of imaging findings on patient management and outcome and the importance of performing high-resolution tailored examinations adapted to the clinical situation are discussed.

  2. Imaging of the optic nerve

    International Nuclear Information System (INIS)

    Becker, Minerva; Masterson, Karen; Delavelle, Jacqueline; Viallon, Magalie; Vargas, Maria-Isabel; Becker, Christoph D.

    2010-01-01

    This article provides an overview of the imaging findings of diseases affecting the optic nerve with special emphasis on clinical-radiological correlation and on the latest technical developments in MR imaging and CT. The review deals with congenital malformations, tumors, toxic/nutritional and degenerative entities, inflammatory and infectious diseases, compressive neuropathy, vascular conditions and trauma involving the optic nerve from its ocular segment to the chiasm. The implications of imaging findings on patient management and outcome and the importance of performing high-resolution tailored examinations adapted to the clinical situation are discussed.

  3. Transvenous stimulation of the renal sympathetic nerves increases systemic blood pressure: a potential new treatment option for neurocardiogenic syncope.

    Science.gov (United States)

    Madhavan, Malini; Desimone, Christopher V; Ebrille, Elisa; Mulpuru, Siva K; Mikell, Susan B; Johnson, Susan B; Suddendorf, Scott H; Ladewig, Dorothy J; Gilles, Emily J; Danielsen, Andrew J; Asirvatham, Samuel J

    2014-10-01

    Neurocardiogenic syncope (NCS) is a common and sometimes debilitating disorder, with no consistently effective treatment. NCS is due to a combination of bradycardia and vasodilation leading to syncope. Although pacemaker devices have been tried in treating the bradycardic aspect of NCS, no device-based therapy exists to treat the coexistent vasodilation that occurs. The renal sympathetic innervation has been the target of denervation to treat hypertension. We hypothesized that stimulation of the renal sympathetic nerves can increase blood pressure and counteract vasodilation in NCS. High-frequency stimulation (800-900 pps, 10 V, 30-200 seconds) was performed using a quadripolar catheter in the renal vein of 7 dogs and 1 baboon. A significant increase in blood pressure (BP; mean [SD] systolic BP 117 [±28] vs. 128 [±33], diastolic BP 75 [±19] vs. 87 [±29] mmHg) was noted during the stimulation, which returned to baseline after cessation of stimulation. The mean increase in systolic and diastolic BP was 13.0 (±3.3) (P = 0.006) and 10.2 (±4.6) (P = 0.08), respectively. We report the first ever study of feasibility and safety of high-frequency electrical stimulation of the renal sympathetic innervation to increase BP in animal models. This has potential applications in the treatment of hypotensive states such as NCS. © 2014 Wiley Periodicals, Inc.

  4. Cardiorespiratory Coupling: Common Rhythms in Cardiac, Sympathetic, and Respiratory Activities

    Science.gov (United States)

    Dick, Thomas E.; Hsieh, Yee-Hsee; Dhingra, Rishi R.; Baekey, David M.; Galán, Roberto F.; Wehrwein, Erica; Morris, Kendall F.

    2014-01-01

    Cardiorespiratory coupling is an encompassing term describing more than the well-recognized influences of respiration on heart rate and blood pressure. Our data indicate that cardiorespiratory coupling reflects a reciprocal interaction between autonomic and respiratory control systems, and the cardiovascular system modulates the ventilatory pattern as well. For example, cardioventilatory coupling refers to the influence of heart beats and arterial pulse pressure on respiration and is the tendency for the next inspiration to start at a preferred latency after the last heart beat in expiration. Multiple complementary, well-described mechanisms mediate respiration’s influence on cardiovascular function, whereas mechanisms mediating the cardiovascular system’s influence on respiration may only be through the baroreceptors but are just being identified. Our review will describe a differential effect of conditioning rats with either chronic intermittent or sustained hypoxia on sympathetic nerve activity but also on ventilatory pattern variability. Both intermittent and sustained hypoxia increase sympathetic nerve activity after 2 weeks but affect sympatho-respiratory coupling differentially. Intermittent hypoxia enhances sympatho-respiratory coupling, which is associated with low variability in the ventilatory pattern. In contrast, after constant hypobaric hypoxia, 1-to-1 coupling between bursts of sympathetic and phrenic nerve activity is replaced by 2-to-3 coupling. This change in coupling pattern is associated with increased variability of the ventilatory pattern. After baro-denervating hypobaric hypoxic-conditioned rats, splanchnic sympathetic nerve activity becomes tonic (distinct bursts are absent) with decreases during phrenic nerve bursts and ventilatory pattern becomes regular. Thus, conditioning rats to either intermittent or sustained hypoxia accentuates the reciprocal nature of cardiorespiratory coupling. Finally, identifying a compelling physiologic

  5. Noninvasive evaluation of sympathetic nervous system in human heart by positron emission tomography

    International Nuclear Information System (INIS)

    Schwaiger, M.; Kalff, V.; Rosenspire, K.; Haka, M.S.; Molina, E.; Hutchins, G.D.; Deeb, M.; Wolfe, E. Jr.; Wieland, D.M.

    1990-01-01

    The noninvasive functional characterization of the cardiac sympathetic nervous system by imaging techniques may provide important pathophysiological information in various cardiac disease states. Hydroxyephedrine labeled with carbon 11 has been developed as a new catecholamine analogue to be used in the in vivo evaluation of presynaptic adrenergic nerve terminals by positron emission tomography (PET). To determine the feasibility of this imaging approach in the human heart, six normal volunteers and five patients with recent cardiac transplants underwent dynamic PET imaging after intravenous injection of 20 mCi [11C]hydroxyephedrine. Blood and myocardial tracer kinetics were assessed using a regions-of-interest approach. In normal volunteers, blood 11C activity cleared rapidly, whereas myocardium retained 11C activity with a long tissue half-life. Relative tracer retention in the myocardium averaged 79 +/- 31% of peak activity at 60 minutes after tracer injection. The heart-to-blood 11C activity ratio exceeded 6:1 as soon as 30 minutes after tracer injection, yielding excellent image quality. Little regional variation of tracer retention was observed, indicating homogeneous sympathetic innervation throughout the left ventricle. In the transplant recipients, myocardial [11C]hydroxyephedrine retention at 60 minutes was significantly less (-82%) than that of normal volunteers, indicating only little non-neuronal binding of the tracer in the denervated human heart. Thus, [11C]hydroxyephedrine, in combination with dynamic PET imaging, allows the noninvasive delineation of myocardial adrenergic nerve terminals. Tracer kinetic modeling may permit quantitative assessment of myocardial catecholamine uptake, which will in turn provide insights into the effects of various disease processes on the neuronal integrity of the heart

  6. Sympathetic Responses to Central Hypovolemia: New Insights from Microneurographic Recordings

    Science.gov (United States)

    2012-04-26

    Surgical Research, Fort Sam Houston, TX, USA 2 Department of Health and Kinesiology , The University of Texas at San Antonio, San Antonio, TX, USA Edited...suggested that this phenomenon may represent sympathetic baroreflex deafferentation (Cooke et al., 2009), as the fused bursts observed during intense ...Convertino, V. A. (2009). Muscle sympathetic nerve activity during intense lower body negative pressure to presyn- cope in humans. J. Physiol. (Lond

  7. US and MR imaging of peripheral nerves in leprosy

    International Nuclear Information System (INIS)

    Martinoli, C.; Derchi, L.E.; Gandolfo, N.; Bertolotto, M.; Bianchi, S.; Fiallo, P.; Nunzi, E.

    2000-01-01

    Objective. To analyze peripheral nerves with ultrasonography (US) and magnetic resonance imaging (MR) in leprosy and assess the role of imaging in leprosy patients. Results. Leprosy nerves were classified into three groups based on imaging appearance: group I consisted of 17 normal-appearing nerves; group II, of 30 enlarged nerves with fascicular abnormalities; group III, of 11 nerves with absent fascicular structure. Group II nerves were from patients subjected to reversal reactions; 75% of patients with group III nerves had a history of erythema nodosum leprosum. Nerve compression in osteofibrous tunnels was identified in 33% of group II and 18% of group III nerves. Doppler US and MR imaging were 74% and 92% sensitive in identifying active reactions, based on detection of endoneural color flow signals, long T2 and Gd enhancement. In 64% of cases, follow-up studies showed decreased color flow and Gd uptake after steroids and decompressive surgery.Conclusions. US and MR imaging are able to detect nerves abnormalities in leprosy. Active reversal reactions are indicated by endoneural color flow signals as well as by an increased T2 signal and Gd enhancement. These signs would suggest rapid progression of nerve damage and a poor prognosis unless antireactional treatment is started. (orig.)

  8. US and MR imaging of peripheral nerves in leprosy

    Energy Technology Data Exchange (ETDEWEB)

    Martinoli, C. [Department of Radiology ' ' R' ' , DICMI, University of Genoa, Genoa (Italy); Cattedra di Radiologia ' ' R' ' , Universita di Genova, Largo Rosanna Benzi, 8, I-16132 Genoa (Italy); Derchi, L.E.; Gandolfo, N. [Department of Radiology ' ' R' ' , DICMI, University of Genoa, Genoa (Italy); Bertolotto, M. [Department of Radiology, University of Trieste, Strada di Fiume, I-34149 Trieste (Italy); Bianchi, S. [Division de Radiodiagnostic. Hopital Cantonal Huniversitaire, Rue Micheli du Crest, Geneva (Switzerland); Fiallo, P.; Nunzi, E. [Department of Tropical Medicine, University of Genoa, Largo Rosanna Benzi 8, I-16132 Genoa (Italy)

    2000-03-30

    Objective. To analyze peripheral nerves with ultrasonography (US) and magnetic resonance imaging (MR) in leprosy and assess the role of imaging in leprosy patients. Results. Leprosy nerves were classified into three groups based on imaging appearance: group I consisted of 17 normal-appearing nerves; group II, of 30 enlarged nerves with fascicular abnormalities; group III, of 11 nerves with absent fascicular structure. Group II nerves were from patients subjected to reversal reactions; 75% of patients with group III nerves had a history of erythema nodosum leprosum. Nerve compression in osteofibrous tunnels was identified in 33% of group II and 18% of group III nerves. Doppler US and MR imaging were 74% and 92% sensitive in identifying active reactions, based on detection of endoneural color flow signals, long T2 and Gd enhancement. In 64% of cases, follow-up studies showed decreased color flow and Gd uptake after steroids and decompressive surgery.Conclusions. US and MR imaging are able to detect nerves abnormalities in leprosy. Active reversal reactions are indicated by endoneural color flow signals as well as by an increased T2 signal and Gd enhancement. These signs would suggest rapid progression of nerve damage and a poor prognosis unless antireactional treatment is started. (orig.)

  9. Sympathetic Blocks Provided Sustained Pain Relief in a Patient with Refractory Painful Diabetic Neuropathy

    Directory of Open Access Journals (Sweden)

    Jianguo Cheng

    2012-01-01

    Full Text Available The sympathetic nervous system has been implicated in pain associated with painful diabetic neuropathy. However, therapeutic intervention targeted at the sympathetic nervous system has not been established. We thus tested the hypothesis that sympathetic nerve blocks significantly reduce pain in a patient with painful diabetic neuropathy who has failed multiple pharmacological treatments. The diagnosis of small fiber sensory neuropathy was based on clinical presentations and confirmed by skin biopsies. A series of 9 lumbar sympathetic blocks over a 26-month period provided sustained pain relief in his legs. Additional thoracic paravertebral blocks further provided control of the pain in the trunk which can occasionally be seen in severe diabetic neuropathy cases, consequent to extensive involvement of the intercostal nerves. These blocks provided sustained and significant pain relief and improvement of quality of life over a period of more than two years. We thus provided the first clinical evidence supporting the notion that sympathetic nervous system plays a critical role in painful diabetic neuropathy and sympathetic blocks can be an effective management modality of painful diabetic neuropathy. We concluded that the sympathetic nervous system is a valuable therapeutic target of pharmacological and interventional modalities of treatments in painful diabetic neuropathy patients.

  10. Direct conscious telemetry recordings demonstrate increased renal sympathetic nerve activity in rats with chronic kidney disease

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    Ibrahim M Salman

    2015-08-01

    Full Text Available Chronic kidney disease (CKD is associated with sympathetic hyperactivity and impaired blood pressure control reflex responses, yet direct evidence demonstrating these features of autonomic dysfunction in conscious animals is still lacking. Here we measured renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP using telemetry-based recordings in a rat model of CKD, the Lewis Polycystic Kidney (LPK rat, and assessed responses to chemoreflex activation and acute stress. Male LPK and Lewis control animals (total n=16 were instrumented for telemetric recording of RSNA and MAP. At 12–13 weeks-of-age, resting RSNA and MAP, sympathetic and haemodynamic responses to both peripheral (hypoxia: 10% O2 and central chemoreflex (hypercapnia: 7% CO2 activation and acute stress (open-field exposure, were measured. As indicators of renal function, urinary protein (UPro and creatinine (Ucr levels were assessed. LPK rats had higher resting RSNA (1.2±0.1 vs. 0.6±0.1 µV, p<0.05 and MAP (151±8 vs. 97±2 mmHg, p<0.05 compared to Lewis. MAP was negatively correlated with Ucr (r=-0.80, p=0.002 and positively correlated with RSNA (r=0.66, p=0.014, with multiple linear regression modeling indicating the strongest correlation was with Ucr. RSNA and MAP responses to activation of the central chemoreflex and open-field stress were reduced in the LPK relative to the Lewis (all p<0.05. This is the first description of dual conscious telemetry recording of RSNA and MAP in a genetic rodent model of CKD. Elevated RSNA is likely a key contributor to the marked hypertension in this model, while attenuated RSNA and MAP responses to central chemoreflex activation and acute stress in the LPK indicate possible deficits in the neural processing of autonomic outflows evoked by these sympathoexcitatory pathways.

  11. Chemistry and biology of radiotracers that target changes in sympathetic and parasympathetic nervous systems in heart disease.

    Science.gov (United States)

    Eckelman, William C; Dilsizian, Vasken

    2015-06-01

    Following the discovery of the sympathetic and parasympathetic nervous system, numerous adrenoceptor drugs were radiolabeled and potent radioligands were prepared in order to image the β-adrenergic and the muscarinic systems. But the greatest effort has been in preparing noradrenaline analogs, such as norepinephrine, (11)C-metahydroxyephedrine, and (123)I-metaiodobenzylguanidine that measure cardiac sympathetic nerve varicosities. Given the technical and clinical challenges in designing and validating targeted adrenoceptor-binding radiotracers, namely the heavily weighted flow dependence and relatively low target-to-background ratio, both requiring complicated mathematic analysis, and the inability of targeted adrenoceptor radioligands to have an impact on clinical care of heart disease, the emphasis has been on radioligands monitoring the norepinephrine pathway. The chemistry and biology of such radiotracers, and the clinical and prognostic impact of these innervation imaging studies in patients with heart disease, are examined. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  12. Enhancement of the facial nerve at MR imaging

    International Nuclear Information System (INIS)

    Gebarski, S.S.; Telian, S.; Niparko, J.

    1990-01-01

    In the few cases studied, normal facial nerves are reported to show no MR enhancement. Because this did not fit clinical experience, the authors designed a retrospective imaging review with anatomic correlation. Between June 1989 and June 1990, 175 patients underwent focused temporal bone MR imaging before and after administration of intravenous gadopentetate dimeglumine (0.1 mmol/kg). Exclusion criteria for the study included facial nerve dysfunction (subjective or objective); facial nerve mass; central nervous system infection, inflammation, or trauma; neurofibromatosis; or previous cranial surgery of any type. The following sequences were reviewed: GE 1.5-T axial spin-echo TR 567 msec, TE 20 msec, 256 x 192, 2.0 excitations, 20-cm field of view, 3-mm section thickness. Imaging analysis was a side-by side comparison of the images and region-of-interest quantified signal intensity. Anatomic correlation included a comparison with dissection and axial histologic sections. Ninety-three patients (aged 15-75 years) were available for imaging analysis after the exclusionary criteria were applied. With 46 patients (92 facial nerves) analyzed, they found that 76 nerves (83%) showed easily visible gadopentetate dimeglumine enhancement, especially about the geniculate ganglia. Sixteen (17%) of the 92 nerves did not show visible enhancement, but region-of-interest analysis showed increased intensity after gadopentetate dimeglumine administration. Sixteen patients (42%) showed right-to-left asymmetry in facial nerve enhancement. The facial nerves showed enhancement in the geniculate, tympanic, and fallopian portions; the facial nerve within the IAC showed no enhancement. This corresponded exactly with the topographic features of a circummeural arterial/venous plexus seen on the anatomic preparations

  13. Imaging of the nerves of the knee region

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    Damarey, B., E-mail: benjdam@hotmail.com [Service de Radiologie et d’Imagerie musculosquelettique, CCIAL, Hôpital Roger Salengro, CHRU de Lille, Rue Emile Laine, 59037 Lille Cedex (France); Laboratoire d’anatomie, Faculté de médecine, CHRU de Lille, 1 Place de Verdun, 59045 Lille Cedex (France); Demondion, X. [Service de Radiologie et d’Imagerie musculosquelettique, CCIAL, Hôpital Roger Salengro, CHRU de Lille, Rue Emile Laine, 59037 Lille Cedex (France); Laboratoire d’anatomie, Faculté de médecine, CHRU de Lille, 1 Place de Verdun, 59045 Lille Cedex (France); Wavreille, G. [Laboratoire d’anatomie, Faculté de médecine, CHRU de Lille, 1 Place de Verdun, 59045 Lille Cedex (France); Service d’orthopédie, Hôpital Roger Salengro, CHRU de Lille, Rue Emile Laine, 59037 Lille Cedex (France); Pansini, V.; Balbi, V.; Cotten, A. [Service de Radiologie et d’Imagerie musculosquelettique, CCIAL, Hôpital Roger Salengro, CHRU de Lille, Rue Emile Laine, 59037 Lille Cedex (France)

    2013-01-15

    Peripheral neuropathies are a frequent, but often underdiagnosed, cause of pain and functional impairment. The clinical symptoms can be subtle, and other neurologic or non neurologic clinical entities are often evoked. MRI and ultrasonography are the imaging modalities of choice for depicting nerves and assessing neuropathies. Common neuropathies in the knee area involve the saphenous, the tibial, the common peroneal and the sural nerves. The most frequent mechanisms of nerve injury in this area are nerve entrapment and nerve stretching. A perfect knowledge of the normal imaging anatomy is essential for accurate assessment of neuropathies. In this article, we will review the anatomy of the nerves around the knee, and their normal and pathological appearance.

  14. Imaging of the nerves of the knee region

    International Nuclear Information System (INIS)

    Damarey, B.; Demondion, X.; Wavreille, G.; Pansini, V.; Balbi, V.; Cotten, A.

    2013-01-01

    Peripheral neuropathies are a frequent, but often underdiagnosed, cause of pain and functional impairment. The clinical symptoms can be subtle, and other neurologic or non neurologic clinical entities are often evoked. MRI and ultrasonography are the imaging modalities of choice for depicting nerves and assessing neuropathies. Common neuropathies in the knee area involve the saphenous, the tibial, the common peroneal and the sural nerves. The most frequent mechanisms of nerve injury in this area are nerve entrapment and nerve stretching. A perfect knowledge of the normal imaging anatomy is essential for accurate assessment of neuropathies. In this article, we will review the anatomy of the nerves around the knee, and their normal and pathological appearance

  15. Contributions of central command and muscle feedback to sympathetic nerve activity in contracting human skeletal muscle

    Directory of Open Access Journals (Sweden)

    Daniel eBoulton

    2016-05-01

    Full Text Available During voluntary contractions, muscle sympathetic nerve activity (MSNA to contracting muscles increases in proportion to force but the underlying mechanisms are not clear. To shed light on these mechanisms, particularly the influences of central command and muscle afferent feedback, the present study tested the hypothesis that MSNA is greater during voluntary compared with electrically-evoked contractions. Seven male subjects performed a series of 1-minute isometric dorsiflexion contractions (left leg separated by 2-minute rest periods, alternating between voluntary and electrically-evoked contractions at similar forces (5-10 % of maximum. MSNA was recorded continuously (microneurography from the left peroneal nerve and quantified from cardiac-synchronised, negative-going spikes in the neurogram. Compared with pre-contraction values, MSNA increased by 51 ± 34 % (P 0.05. MSNA analysed at 15-s intervals revealed that this effect of voluntary contraction appeared 15-30 s after contraction onset (P < 0.01, remained elevated until the end of contraction, and disappeared within 15 s after contraction. These findings suggest that central command, and not feedback from contracting muscle, is the primary mechanism responsible for the increase in MSNA to contracting muscle. The time-course of MSNA suggests that there is a longer delay in the onset of this effect compared with its cessation after contraction.

  16. Renal Sympathetic Denervation: Hibernation or Resurrection?

    Science.gov (United States)

    Papademetriou, Vasilios; Doumas, Michael; Tsioufis, Costas

    The most current versions of renal sympathetic denervation have been invented as minimally invasive approaches for the management of drug-resistant hypertension. The anatomy, physiology and pathophysiology of renal sympathetic innervation provide a strong background supporting an important role of the renal nerves in the regulation of blood pressure (BP) and volume. In addition, historical data with surgical sympathectomy and experimental data with surgical renal denervation indicate a beneficial effect on BP levels. Early clinical studies with transcatheter radiofrequency ablation demonstrated impressive BP reduction, accompanied by beneficial effects in target organ damage and other disease conditions characterized by sympathetic overactivity. However, the failure of the SYMPLICITY 3 trial to meet its primary efficacy end point raised a lot of concerns and put the field of renal denervation into hibernation. This review aims to translate basic research into clinical practice by presenting the anatomical and physiological basis for renal sympathetic denervation, critically discussing the past and present knowledge in this field, where we stand now, and also speculating about the future of the intervention and potential directions for research. © 2016 S. Karger AG, Basel.

  17. The morphological substrate for Renal Denervation : Nerve distribution patterns and parasympathetic nerves. A post-mortem histological study

    NARCIS (Netherlands)

    van Amsterdam, Wouter A C; Blankestijn, Peter J; Goldschmeding, Roel; Bleys, Ronald L A W

    2015-01-01

    BACKGROUND: Renal Denervation as a possible treatment for hypertension has been studied extensively, but knowledge on the distribution of nerves surrounding the renal artery is still incomplete. While sympathetic and sensory nerves have been demonstrated, there is no mention of the presence of

  18. Study of sympathetic nervous function under effort induced ischemia in patients with angina pectoris with I-123 metaiodobenzylguanidine (MIBG) myocardial SPECT images

    International Nuclear Information System (INIS)

    Tanaka, Takeshi; Aizawa, Tadanori; Kato, Kazuzo; Ogasawara, Ken; Sakuma, Toru; Kirigaya, Hajime; Hirosaka, Akira; Igarashi, Masaki

    1990-01-01

    I-123 metaiodobenzylguanidine (MIBG) is a norepinephrine analog, which can be used to study the sympathetic nervous function of the heart. With MIBG myocardial SPECT images sympathetic nervous function under effort induced ischemia were studied in 18 patients with significant coronary artery lesions. In 5 patients with effort induced ischemic region in stress Tl-201 myocardial images rest MIBG images were collected and then exercise stress test was performed. Patients continued exercising for 3 minutes after onset of symptom. Post-stress MIBG images were collected. Definite ischemic region was noted in stress Tl-201 myocardial images, however no differences were noted between rest and post-stress MIBG images. These results suggested that exercise induced ischemia did not enhance release of uptaken MIBG. In 13 patients with significant coronary artery lesions symptom-limited exercise stress test was performed MIBG and Tl-201 were simultaneously injected at onset of symptom and patients continued exercising for an additional one minute. In 6 cases (46%, 6/13) MIBG defects with Tl-201 uptake were noted. These results showed that exercise induced ischemia depressed net MIBG uptake and that sympathetic nervous function (MIBG images) may be more sensitive to ischemic damage than muscle (Tl-201 images). It is suggested that exercise induced ischemia depressed reuptake of norepinephrine at sympathetic nervous endings. MIBG myocardial SPECT images may be useful for evaluating sympathetic nervous function under ischemia. (author)

  19. The role of sympathetic nervous system in the progression of chronic kidney disease in the era of catheter based sympathetic renal denervation.

    Science.gov (United States)

    Petras, Dimitrios; Koutroutsos, Konstantinos; Kordalis, Athanasios; Tsioufis, Costas; Stefanadis, Christodoulos

    2013-08-01

    The kidney has been shown to be critically involved as both trigger and target of sympathetic nervous system overactivity in both experimental and clinical studies. Renal injury and ischemia, activation of renin angiotensin system and dysfunction of nitric oxide system have been implicated in adrenergic activation from kidney. Conversely, several lines of evidence suggest that sympathetic overactivity, through functional and morphological alterations in renal physiology and structure, may contribute to kidney injury and chronic kidney disease progression. Pharmacologic modulation of sympathetic nervous system activity has been found to have a blood pressure independent renoprotective effect. The inadequate normalization of sympathoexcitation by pharmacologic treatment asks for novel treatment options. Catheter based renal denervation targets selectively both efferent and afferent renal nerves and functionally denervates the kidney providing blood pressure reduction in clinical trials and renoprotection in experimental models by ameliorating the effects of excessive renal sympathetic drive. This review will focus on the role of sympathetic overactivity in the pathogenesis of kidney injury and CKD progression and will speculate on the effect of renal denervation to these conditions.

  20. Iodine-123 metaiodobenzylguanidine imaging of the heart in idiopathic congestive cardiomyopathy and cardiac transplants

    International Nuclear Information System (INIS)

    Glowniak, J.V.; Turner, F.E.; Gray, L.L.; Palac, R.T.; Lagunas-Solar, M.C.; Woodward, W.R.

    1989-01-01

    Iodine-123 metaiodobenzylguanidine ([ 123 I]MIBG) is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. In this study, cardiac imaging with [ 123 I]MIBG was performed in patients with idiopathic congestive cardiomyopathy and compared to normal controls. Initial uptake, half-time of tracer within the heart, and heart to lung ratios were all significantly reduced in patients compared to normals. Uptake in lungs, liver, salivary glands, and spleen was similar in controls and patients with cardiomyopathy indicating that decreased MIBG uptake was not a generalized abnormality in these patients. Iodine-123 MIBG imaging was also performed in cardiac transplant patients to determine cardiac nonneuronal uptake. Uptake in transplants was less than 10% of normals in the first 2 hr and nearly undetectable after 16 hr. The decreased uptake of MIBG suggests cardiac sympathetic nerve dysfunction while the rapid washout of MIBG from the heart suggests increased cardiac sympathetic nerve activity in idiopathic congestive cardiomyopathy

  1. Can preoperative MR imaging predict optic nerve invasion of retinoblastoma?

    International Nuclear Information System (INIS)

    Song, Kyoung Doo; Eo, Hong; Kim, Ji Hye; Yoo, So-Young; Jeon, Tae Yeon

    2012-01-01

    Purpose: To evaluate the accuracy of pre-operative MRI for the detection of optic nerve invasion in retinoblastoma. Materials and methods: Institutional review board approval and informed consent were waived for this retrospective study. A total of 41 patients were included. Inclusion criteria were histologically proven retinoblastoma, availability of diagnostic-quality preoperative MR images acquired during the 4 weeks before surgery, unilateral retinoblastoma, and normal-sized optic nerve. Two radiologists retrospectively reviewed the MR images independently. Five imaging findings (diffuse mild optic nerve enhancement, focal strong optic nerve enhancement, optic sheath enhancement, tumor location, and tumor size) were evaluated against optic nerve invasion of retinoblastoma. The predictive performance of all MR imaging findings for optic nerve invasion was also evaluated by the receiver operating characteristic curve analysis. Results: Optic nerve invasion was histopathologically confirmed in 24% of study population (10/41). The differences in diffuse mild enhancement, focal strong enhancement, optic sheath enhancement, and tumor location between patients with optic nerve invasion and patients without optic nerve invasion were not significant. Tumor sizes were 16.1 mm (SD: 2.2 mm) and 14.9 mm (SD: 3.6 mm) in patients with and without optic nerve involvement, respectively (P = 0.444). P-Values from binary logistic regression indicated that all five imaging findings were not significant predictors of tumor invasion of optic nerve. The AUC values of all MR imaging findings for the prediction of optic nerve invasion were 0.689 (95% confidence interval: 0.499–0.879) and 0.653 (95% confidence interval: 0.445–0.861) for observer 1 and observer 2, respectively. Conclusion: Findings of MRI in patients with normal-sized optic nerves have limited usefulness in preoperatively predicting the presence of optic nerve invasion in retinoblastoma.

  2. Can preoperative MR imaging predict optic nerve invasion of retinoblastoma?

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kyoung Doo, E-mail: kdsong0308@gmail.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Eo, Hong, E-mail: rtombow@gmail.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Kim, Ji Hye, E-mail: jhkate.kim@samsung.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Yoo, So-Young, E-mail: sy1131.yoo@samsung.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Jeon, Tae Yeon, E-mail: hathor97.jeon@samsung.com [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of)

    2012-12-15

    Purpose: To evaluate the accuracy of pre-operative MRI for the detection of optic nerve invasion in retinoblastoma. Materials and methods: Institutional review board approval and informed consent were waived for this retrospective study. A total of 41 patients were included. Inclusion criteria were histologically proven retinoblastoma, availability of diagnostic-quality preoperative MR images acquired during the 4 weeks before surgery, unilateral retinoblastoma, and normal-sized optic nerve. Two radiologists retrospectively reviewed the MR images independently. Five imaging findings (diffuse mild optic nerve enhancement, focal strong optic nerve enhancement, optic sheath enhancement, tumor location, and tumor size) were evaluated against optic nerve invasion of retinoblastoma. The predictive performance of all MR imaging findings for optic nerve invasion was also evaluated by the receiver operating characteristic curve analysis. Results: Optic nerve invasion was histopathologically confirmed in 24% of study population (10/41). The differences in diffuse mild enhancement, focal strong enhancement, optic sheath enhancement, and tumor location between patients with optic nerve invasion and patients without optic nerve invasion were not significant. Tumor sizes were 16.1 mm (SD: 2.2 mm) and 14.9 mm (SD: 3.6 mm) in patients with and without optic nerve involvement, respectively (P = 0.444). P-Values from binary logistic regression indicated that all five imaging findings were not significant predictors of tumor invasion of optic nerve. The AUC values of all MR imaging findings for the prediction of optic nerve invasion were 0.689 (95% confidence interval: 0.499–0.879) and 0.653 (95% confidence interval: 0.445–0.861) for observer 1 and observer 2, respectively. Conclusion: Findings of MRI in patients with normal-sized optic nerves have limited usefulness in preoperatively predicting the presence of optic nerve invasion in retinoblastoma.

  3. [From anatomy to image: the cranial nerves at MRI].

    Science.gov (United States)

    Conforti, Renata; Marrone, Valeria; Sardaro, Angela; Faella, Pierluigi; Grassi, Roberta; Cappabianca, Salvatore

    2013-01-01

    In this article, we review the expected course of each of the 12 cranial nerves. Traditional magnetic resonance imaging depicts only the larger cranial nerves but SSFP sequences of magnetic resonance imaging are capable of depicting the cisternal segments of 12 cranial nerves and also provide submillimetric spatial resolution.

  4. Sympathetic Innervation during Development Is Necessary for Pancreatic Islet Architecture and Functional Maturation

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    Philip Borden

    2013-07-01

    Full Text Available Sympathetic neurons depend on target-derived neurotrophic cues to control their survival and growth. However, whether sympathetic innervation contributes reciprocally to the development of target tissues is less clear. Here, we report that sympathetic innervation is necessary for the formation of the pancreatic islets of Langerhans and for their functional maturation. Genetic or pharmacological ablation of sympathetic innervation during development resulted in altered islet architecture, reduced insulin secretion, and impaired glucose tolerance in mice. Similar defects were observed with pharmacological blockade of β-adrenergic signaling. Conversely, the administration of a β-adrenergic agonist restored islet morphology and glucose tolerance in deinnervated animals. Furthermore, in neuron-islet cocultures, sympathetic neurons promoted islet cell migration in a β-adrenergic-dependent manner. This study reveals that islet architecture requires extrinsic inductive cues from neighboring tissues such as sympathetic nerves and suggests that early perturbations in sympathetic innervation might underlie metabolic disorders.

  5. DIC imaging for identification of motor and sensory nerves

    Directory of Open Access Journals (Sweden)

    Dayu Chen

    2016-09-01

    Full Text Available Identification of motor and sensory nerves is important in applications such as nerve injury repair. Conventional practice relies on time consuming staining methods for this purpose. Here, we use laser scanning infrared differential interference contrast (IR-DIC microscopy for label-free observation of the two types of nerve. Ventral and dorsal nerve roots of adult beagle dogs were collected and sections of different thicknesses were imaged with an IR-DIC microscope. Different texture patterns of the IR-DIC images of the motor and sensory nerve can be distinguished when the section thickness increases to 40μm. This suggests that nerve fibers in motor and sensory nerves have different distribution patterns. The result hints a potential new way for more rapid identification of nerve type in peripheral nerve repair surgery.

  6. Highly localized interactions between sensory neurons and sprouting sympathetic fibers observed in a transgenic tyrosine hydroxylase reporter mouse

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    Zhang Jun-Ming

    2011-07-01

    Full Text Available Abstract Background Sprouting of sympathetic fibers into sensory ganglia occurs in many preclinical pain models, providing a possible anatomical substrate for sympathetically enhanced pain. However, the functional consequences of this sprouting have been controversial. We used a transgenic mouse in which sympathetic fibers expressed green fluorescent protein, observable in live tissue. Medium and large diameter lumbar sensory neurons with and without nearby sympathetic fibers were recorded in whole ganglion preparations using microelectrodes. Results After spinal nerve ligation, sympathetic sprouting was extensive by 3 days. Abnormal spontaneous activity increased to 15% and rheobase was reduced. Spontaneously active cells had Aαβ conduction velocities but were clustered near the medium/large cell boundary. Neurons with sympathetic basket formations had a dramatically higher incidence of spontaneous activity (71% and had lower rheobase than cells with no sympathetic fibers nearby. Cells with lower density nearby fibers had intermediate phenotypes. Immunohistochemistry of sectioned ganglia showed that cells surrounded by sympathetic fibers were enriched in nociceptive markers TrkA, substance P, or CGRP. Spontaneous activity began before sympathetic sprouting was observed, but blocking sympathetic sprouting on day 3 by cutting the dorsal ramus in addition to the ventral ramus of the spinal nerve greatly reduced abnormal spontaneous activity. Conclusions The data suggest that early sympathetic sprouting into the sensory ganglia may have highly localized, excitatory effects. Quantitatively, neurons with sympathetic basket formations may account for more than half of the observed spontaneous activity, despite being relatively rare. Spontaneous activity in sensory neurons and sympathetic sprouting may be mutually re-enforcing.

  7. Sympathetic skin responses in patients with hyperthyroidism.

    Science.gov (United States)

    Gozke, E; Ozyurt, Z; Dortcan, N; Ore, O; Kocer, A; Ozer, E

    2007-01-01

    The aim of this study was to investigate the disorders of sympathetic nervous system in patients with hyperthyroidism using sympathetic skin response (SSR). Twenty-two newly diagnosed cases with hyperthyroidism were included in the study. The results were compared with those of 20 healthy controls. SSR was recorded with the contralateral electrical stimulation of the median nerve (of the upper extremities) and tibial nerve (of the lower extremities) with active electrodes placed on palms and soles and reference electrodes attached on the dorsal aspects of hands and feet. Ages of the cases with hyperthyroidism and controls ranged between 15-65 years (mean: 46.7 +/- 15.0 years) and 24-62 years (mean: 39.6 +/- 9.8 years) respectively (p > 0.05). In all the control subjects SSR could be obtained, while from the lower extremities of 4 cases with hyperthyroidism (18.0%) SSR could not be elicited. Mean SSR latencies of lower extremities were found significantly longer than control group (p nervous system involvement in cases with hyperthyroidism.

  8. Imaging assessment of isolated lesions affecting cranial nerve III

    International Nuclear Information System (INIS)

    Garcia, Marcelo de Mattos; Martins, Jose Carlos Tadeu

    2005-01-01

    The aim of this study is to review the anatomy and main pathologic conditions affecting cranial nerve III using imaging studies, particularly magnetic resonance imaging. Imaging methods are essential in the evaluation of patients with suspected lesions of the oculomotor nerve once signs and symptoms are unspecific and a large number of diseases can affect cranial nerve III. A brief review of the literature is also presented. (author)

  9. Increased Sympathetic Renal Innervation in Hemodialysis Patients Is the Anatomical Substrate of Sympathetic Hyperactivity in End-Stage Renal Disease.

    Science.gov (United States)

    Mauriello, Alessandro; Rovella, Valentina; Anemona, Lucia; Servadei, Francesca; Giannini, Elena; Bove, Pierluigi; Anselmo, Alessandro; Melino, Gerry; Di Daniele, Nicola

    2015-11-26

    Renal denervation represents an emerging treatment for resistant hypertension in patients with end-stage renal disease, but data about the anatomic substrate of this treatment are lacking. Therefore, the aim of this study was to investigate the morphological basis of sympathetic hyperactivity in the setting of hemodialysis patients to identify an anatomical substrate that could warrant the use of this new therapeutic approach. The distribution of sympathetic nerves was evaluated in the adventitia of 38 renal arteries that were collected at autopsy or during surgery from 25 patients: 9 with end-stage renal disease on dialysis (DIAL group) and 16 age-matched control nondialysis patients (CTRL group). Patients in the DIAL group showed a significant increase in nerve density in the internal area of the peri-adventitial tissue (within the first 0.5 mm of the beginning of the adventitia) compared with the CTRL group (4.01±0.30 versus 2.87±0.28×mm(2), P=0.01). Regardless of dialysis, hypertensive patients with signs of severe arteriolar damage had a greater number of nerve endings in the most internal adventitia, and this number was significantly higher than in patients without hypertensive arteriolar damage (3.90±0.36 versus 2.87±0.41×mm(2), P=0.04), showing a correlation with hypertensive arteriolar damage rather than with hypertensive clinical history. The findings from this study provide a morphological basis underlying sympathetic hyperactivity in patients with end-stage renal disease and might offer useful information to improve the use of renal denervation in this group of patients. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  10. Effect of 4G-alpha-glucopyranosyl hesperidin on brown fat adipose tissue- and cutaneous-sympathetic nerve activity and peripheral body temperature.

    Science.gov (United States)

    Shen, Jiao; Nakamura, Hiroyasu; Fujisaki, Yoshiyuki; Tanida, Mamoru; Horii, Yuko; Fuyuki, Risa; Takumi, Hiroko; Shiraishi, Koso; Kometani, Takashi; Nagai, Katsuya

    2009-09-11

    Changes in the activity of the autonomic nervous system are good indicators of alterations in physiological phenomena such as the body temperature, blood glucose, blood pressure. Hesperidin, a flavanone known as vitamin P, has been shown to reduce the levels of serum lipids, cholesterol, and blood pressure. However, hesperidin is not water-soluble and is not well absorbed from the intestine. G-hesperidin (4G-alpha-glucopyranosyl hesperidin) is more water-soluble and more rapidly absorbed than hesperidin. In order to clarify the functions of G-hesperidin, we examined the effects of oral administration of G-hesperidin on interscapular brown adipose tissue-sympathetic nerve activity (BAT-SNA) and cutaneous sympathetic nerve activity (CASNA) in rats weighing about 300 g. In this study, we found that oral administration of 60 mg of G-hesperidin increased the BAT-SNA but decreased the CASNA in urethane-anesthetized rats. Since an elevation in BAT-SNA increases heat production (i.e. body temperature (BT)) and a decrease in CASNA increases cutaneous perfusion, we examined whether oral administration of G-hesperidin had an effect on the peripheral BT in rats. Consequently, we observed that the subcutaneous BT at the caudal end of the back after oral administration of 60 mg of G-hesperidin was significantly higher than the subcutaneous BT after oral administration of water in conscious rats. These findings suggest that G-hesperidin enhances the BAT-SNA and suppresses the CASNA resulting in an increase in the peripheral BT, probably by an increase in the thermogenesis in the BAT and an elevation in the cutaneous blood flow.

  11. Device-based approaches for renal nerve ablation for hypertension and beyond

    Directory of Open Access Journals (Sweden)

    Alicia Ann Thorp

    2015-07-01

    Full Text Available Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy’s efficacy. Disrupting renal afferent sympathetic signalling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic over-activity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of–concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic over-activity is also presented.

  12. Device-based approaches for renal nerve ablation for hypertension and beyond

    Science.gov (United States)

    Thorp, Alicia A.; Schlaich, Markus P.

    2015-01-01

    Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy's efficacy. Disrupting renal afferent sympathetic signaling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic overactivity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of-concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic overactivity is also presented. PMID:26217232

  13. Device-based approaches for renal nerve ablation for hypertension and beyond.

    Science.gov (United States)

    Thorp, Alicia A; Schlaich, Markus P

    2015-01-01

    Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy's efficacy. Disrupting renal afferent sympathetic signaling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic overactivity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of-concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic overactivity is also presented.

  14. Facial nerve palsy: Evaluation by contrast-enhanced MR imaging

    International Nuclear Information System (INIS)

    Kinoshita, T.; Ishii, K.; Okitsu, T.; Okudera, T.; Ogawa, T.

    2001-01-01

    AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma. Kinoshita T. et al. (2001)

  15. Facial nerve palsy: Evaluation by contrast-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, T.; Ishii, K.; Okitsu, T.; Okudera, T.; Ogawa, T

    2001-11-01

    AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma. Kinoshita T. et al. (2001)

  16. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Uei; Tan, Cher Heng [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong [Tan Tock Seng Hospital, Department of Cardiology, Singapore (Singapore)

    2014-08-28

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  17. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    International Nuclear Information System (INIS)

    Pua, Uei; Tan, Cher Heng; Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong

    2015-01-01

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  18. Release of NPY in pig pancreas: Dual parasympathetic and sympathetic regulation

    International Nuclear Information System (INIS)

    Sheikh, S.P.; Holst, J.J.; Skak-Nielsen, T.; Knigge, U.; Warberg, J.; Theodorsson-Norheim, E.; Hoekfelt, T.; Lundberg, J.M.; Schwartz, T.W.

    1988-01-01

    Several lines of evidence have connected neuropeptide Y (NPY), a 36-residue polypeptide, to the sympathetic division of the autonomic nervous system. The authors studied the localization, the molecular characteristics, and the release of NPY and norepinephrine (NE) in the porcine pancreas. Immunohistochemical investigations revealed that NPY nerves around blood vessels were likely to be of adrenergic nature, whereas NPY-immunoreactive fibers close to exocrine and endocrine cells may originate from local ganglia also containing VIP (vasoactive intestinal peptide) and PHI (peptide histidine isoleucine). Electrical stimulation of the splanchnic nerve supply to the isolated perfused pig pancreas resulted in a corelease of NPY and NE into the venous effluent. Stimulation of the vagal nerves caused a sevenfold larger release of NPY without affecting the NE secretion. Characterization of the NPY immunoreactivity in the pancreatic tissue and in the venous effluent by gel filtration, high-performance liquid chromatography, and isoelectric focusing shoed that the immunoreactive NPY was indistinguishable from synthetic porcine NPY. It is concluded that, although NPY is associated with sympathetic perivascular neurons, the majority of the pancreatic NPY-containing nerve fibers are likely to belong to the parasympathetic division of the autonomic nervous system

  19. Nerve-Highlighting Fluorescent Contrast Agents for Image-Guided Surgery

    Directory of Open Access Journals (Sweden)

    Summer L. Gibbs-Strauss

    2011-03-01

    Full Text Available Nerve damage is the major morbidity of many surgeries, resulting in chronic pain, loss of function, or both. The sparing of nerves during surgical procedures is a vexing problem because surrounding tissue often obscures them. To date, systemically administered nerve-highlighting contrast agents that can be used for nerve-sparing image-guided surgery have not been reported. In the current study, physicochemical and optical properties of 4,4‘-[(2-methoxy-1,4-phenylenedi-(1E-2,1-ethenediyl]bis-benzenamine (BMB and a newly synthesized, red-shifted derivative 4-[(1E-2-[4-[(1E-2-[4-aminophenyl]ethenyl]-3-methoxyphenyl]ethenyl]-benzonitrile (GE3082 were characterized in vitro and in vivo. Both agents crossed the blood-nerve barrier and blood-brain barrier and rendered myelinated nerves fluorescent after a single systemic injection. Although both BMB and GE3082 also exhibited significant uptake in white adipose tissue, GE3082 underwent a hypsochromic shift in adipose tissue that provided a means to eliminate the unwanted signal using hyperspectral deconvolution. Dose and kinetic studies were performed in mice to determine the optimal dose and drug-imaging interval. The results were confirmed in rat and pig, with the latter used to demonstrate, for the first time, simultaneous fluorescence imaging of blood vessels and nerves during surgery using the FLARE™ (Fluorescence-Assisted Resection and Exploration imaging system. These results lay the foundation for the development of ideal nerve-highlighting fluorophores for image-guided surgery.

  20. Optogenetic release of norepinephrine from cardiac sympathetic neurons alters mechanical and electrical function.

    Science.gov (United States)

    Wengrowski, Anastasia M; Wang, Xin; Tapa, Srinivas; Posnack, Nikki Gillum; Mendelowitz, David; Kay, Matthew W

    2015-02-01

    Release of norepinephrine (NE) from sympathetic neurons enhances heart rate (HR) and developed force through activation of β-adrenergic receptors, and this sympathoexcitation is a key risk for the generation of cardiac arrhythmias. Studies of β-adrenergic modulation of cardiac function typically involve the administration of exogenous β-adrenergic receptor agonists to directly elicit global β-adrenergic receptor activation by bypassing the involvement of sympathetic nerve terminals. In this work, we use a novel method to activate sympathetic fibres within the myocardium of Langendorff-perfused hearts while measuring changes in electrical and mechanical function. The light-activated optogenetic protein channelrhodopsin-2 (ChR2) was expressed in murine catecholaminergic sympathetic neurons. Sympathetic fibres were then photoactivated to examine changes in contractile force, HR, and cardiac electrical activity. Incidence of arrhythmia was measured with and without exposure to photoactivation of sympathetic fibres, and hearts were optically mapped to detect changes in action potential durations and conduction velocities. Results demonstrate facilitation of both developed force and HR after photostimulated release of NE, with increases in contractile force and HR of 34.5 ± 5.5 and 25.0 ± 9.3%, respectively. Photostimulation of sympathetic fibres also made hearts more susceptible to arrhythmia, with greater incidence and severity. In addition, optically mapped action potentials displayed a small but significant shortening of the plateau phase (-5.5 ± 1.0 ms) after photostimulation. This study characterizes a powerful and clinically relevant new model for studies of cardiac arrhythmias generated by increasing the activity of sympathetic nerve terminals and the resulting activation of myocyte β-adrenergic receptors. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  1. Agmatine suppresses peripheral sympathetic tone by inhibiting N-type Ca(2+) channel activity via imidazoline I2 receptor activation.

    Science.gov (United States)

    Kim, Young-Hwan; Jeong, Ji-Hyun; Ahn, Duck-Sun; Chung, Seungsoo

    2016-08-26

    Agmatine, a putative endogenous ligand of imidazoline receptors, suppresses cardiovascular function by inhibiting peripheral sympathetic tone. However, the molecular identity of imidazoline receptor subtypes and its cellular mechanism underlying the agmatine-induced sympathetic suppression remains unknown. Meanwhile, N-type Ca(2+) channels are important for the regulation of NA release in the peripheral sympathetic nervous system. Therefore, it is possible that agmatine suppresses NA release in peripheral sympathetic nerve terminals by inhibiting Ca(2+) influx through N-type Ca(2+) channels. We tested this hypothesis by investigating agmatine effect on electrical field stimulation (EFS)-evoked contraction and NA release in endothelium-denuded rat superior mesenteric arterial strips. We also investigated the effect of agmatine on the N-type Ca(2+) current in superior cervical ganglion (SCG) neurons in rats. Our study demonstrates that agmatine suppresses peripheral sympathetic outflow via the imidazoline I2 receptor in rat mesenteric arteries. In addition, the agmatine-induced suppression of peripheral vascular sympathetic tone is mediated by modulating voltage-dependent N-type Ca(2+) channels in sympathetic nerve terminals. These results suggest a potential cellular mechanism for the agmatine-induced suppression of peripheral sympathetic tone. Furthermore, they provide basic and theoretical information regarding the development of new agents to treat hypertension. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. High-resolution imaging of neural anatomy and pathology of the neck

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Hyun; Choi, Young Jun; Baek, Jung Hwan [Dept. of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Cheng, Kai Lung [Dept. of Medical Imaging, Chung Shan Medical University Hospital, Taichung (China)

    2017-01-15

    The neck has intricately connected neural structures, including cervical and brachial plexi, the sympathetic system, lower cranial nerves, and their branches. Except for brachial plexus, there has been little research regarding the normal imaging appearance or corresponding pathologies of neural structures in the neck. The development in imaging techniques with better spatial resolution and signal-to-noise ratio has made it possible to see many tiny nerves to predict complications related to image-guided procedures and to better assess treatment response, especially in the management of oncology patients. The purposes of this review is to present imaging-based anatomy of major nerves in the neck and explain their relevant clinical significance according to representative pathologies of regarded nerves in the neck.

  3. Streptozocin-induced type-1 diabetes mellitus results in decreased density of CGRP sensory and TH sympathetic nerve fibers that are positively correlated with bone loss at the mouse femoral neck.

    Science.gov (United States)

    Enríquez-Pérez, Iris A; Galindo-Ordoñez, Karla E; Pantoja-Ortíz, Christian E; Martínez-Martínez, Arisaí; Acosta-González, Rosa I; Muñoz-Islas, Enriqueta; Jiménez-Andrade, Juan M

    2017-08-10

    Type-1 diabetes mellitus (T1DM) results in loss of innervation in some tissues including epidermis and retina; however, the effect on bone innervation is unknown. Likewise, T1DM results in pathological bone loss and increased risk of fracture. Thus, we quantified the density of calcitonin gene-related peptide (CGRP + ) sensory and tyrosine hydroxylase (TH + ) sympathetic nerve fibers and determined the association between the innervation density and microarchitecture of trabecular bone at the mouse femoral neck. Ten weeks-old female mice received 5 daily administrations of streptozocin (i.p. 50mg/kg) or citrate (control group). Twenty weeks later, femurs were analyzed by microCT and processed for immunohistochemistry. Confocal microscopy analysis revealed that mice with T1DM had a significant loss of both CGRP + and TH + nerve fibers in the bone marrow at the femoral neck. Likewise, microCT analysis revealed a significant decrease in the trabecular bone mineral density (tBMD), bone volume/total volume ratio (BV/TB), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) in mice with T1DM as compared to control mice. Analysis of correlation revealed a positive and significant association between density of CGRP + or TH + nerve fibers with tBMD, BV/TV, Tb.Th and Tb.Sp, but not with trabecular number (there was a positive association only for CGRP + ) and degree of anisotropy (DA). This study suggests an interaction between sensory and sympathetic nervous system and T1DM-induced bone loss. Identification of the factors involved in the loss of CGRP + sensory and TH + sympathetic fibers and how they regulate bone loss may result in new avenues to treat T1DM-related osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Subtle involvement of the sympathetic nervous system in amyotrophic lateral sclerosis.

    NARCIS (Netherlands)

    Oey, P.L.; Vos, P.E.; Wieneke, G.H.; Wokke, J.H.J.; Blankestijn, P.J.; Karemaker, J.M.

    2002-01-01

    The literature on the involvement of the autonomic nervous system (ANS) in amyotrophic lateral sclerosis (ALS) is conflicting. We therefore investigated several aspects of autonomic function, namely muscle sympathetic nerve activity (MSNA), blood pressure, cardiac function (electrocardiogram; ECG),

  5. Subtle involvement of the sympathetic nervous system in amyotrophic lateral sclerosis

    NARCIS (Netherlands)

    Oey, P. Liam; Vos, Pieter E.; Wieneke, George H.; Wokke, John H. J.; Blankestijn, Peter J.; Karemaker, John M.

    2002-01-01

    The literature on the involvement of the autonomic nervous system (ANS) in amyotrophic lateral sclerosis (ALS) is conflicting. We therefore investigated several aspects of autonomic function, namely muscle sympathetic nerve activity (MSNA), blood pressure, cardiac function (electrocardiogram; ECG),

  6. The Sympathetic Release Test: A Test Used to Assess Thermoregulation and Autonomic Control of Blood Flow

    Science.gov (United States)

    Tansey, E. A.; Roe, S. M.; Johnson, C. J.

    2014-01-01

    When a subject is heated, the stimulation of temperature-sensitive nerve endings in the skin, and the raising of the central body temperature, results in the reflex release of sympathetic vasoconstrictor tone in the skin of the extremities, causing a measurable temperature increase at the site of release. In the sympathetic release test, the…

  7. Magnetic resonance imaging of facial nerve schwannoma.

    Science.gov (United States)

    Thompson, Andrew L; Aviv, Richard I; Chen, Joseph M; Nedzelski, Julian M; Yuen, Heng-Wai; Fox, Allan J; Bharatha, Aditya; Bartlett, Eric S; Symons, Sean P

    2009-12-01

    This study characterizes the magnetic resonance (MR) appearances of facial nerve schwannoma (FNS). We hypothesize that the extent of FNS demonstrated on MR will be greater compared to prior computed tomography studies, that geniculate involvement will be most common, and that cerebellar pontine angle (CPA) and internal auditory canal (IAC) involvement will more frequently result in sensorineural hearing loss (SNHL). Retrospective study. Clinical, pathologic, and enhanced MR imaging records of 30 patients with FNS were analyzed. Morphologic characteristics and extent of segmental facial nerve involvement were documented. Median age at initial imaging was 51 years (range, 28-76 years). Pathologic confirmation was obtained in 14 patients (47%), and the diagnosis reached in the remainder by identification of a mass, thickening, and enhancement along the course of the facial nerve. All 30 lesions involved two or more contiguous segments of the facial nerve, with 28 (93%) involving three or more segments. The median segments involved per lesion was 4, mean of 3.83. Geniculate involvement was most common, in 29 patients (97%). CPA (P = .001) and IAC (P = .02) involvement was significantly related to SNHL. Seventeen patients (57%) presented with facial nerve dysfunction, manifesting in 12 patients as facial nerve weakness or paralysis, and/or in eight with involuntary movements of the facial musculature. This study highlights the morphologic heterogeneity and typical multisegment involvement of FNS. Enhanced MR is the imaging modality of choice for FNS. The neuroradiologist must accurately diagnose and characterize this lesion, and thus facilitate optimal preoperative planning and counseling.

  8. Impact of aging on cardiac sympathetic innervation measured by {sup 123}I-mIBG imaging in patients with systolic heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Rengo, Giuseppe; Ferrara, Nicola [Scientific Institute of Telese Terme, Salvatore Maugeri Foundation, IRCCS, Telese Terme (Italy); University of Naples Federico II, Division of Geriatrics, Department of Translational Medical Sciences, Naples (Italy); Pagano, Gennaro; Formisano, Roberto; Komici, Klara; Petraglia, Laura; Parisi, Valentina; Femminella, Grazia Daniela; De Lucia, Claudio; Cannavo, Alessandro; Memmi, Alessia; Leosco, Dario [University of Naples Federico II, Division of Geriatrics, Department of Translational Medical Sciences, Naples (Italy); Vitale, Dino Franco [Scientific Institute of Telese Terme, Salvatore Maugeri Foundation, IRCCS, Telese Terme (Italy); Paolillo, Stefania [Institute of Diagnostic and Nuclear Development, SDN Foundation, Naples (Italy); Attena, Emilio [Fatebenefratelli Hospital, Department of Cardiology, Naples (Italy); Pellegrino, Teresa [Institute of Biostructures and Bioimages of the National Council of Research, Naples (Italy); Federico II University of Naples, Division of Imaging, Radiotherapy, Neuroradiology, and Medical Physics, Department of Advanced Biomedical Sciences, Naples (Italy); Dellegrottaglie, Santo [Ospedale Medico-Chirurgico Accreditato Villa dei Fiori, Division of Cardiology, Acerra, Naples (Italy); Trimarco, Bruno; Filardi, Pasquale Perrone [Federico II University of Naples, Division of Cardiology, Department of Advanced Biomedical Sciences, Naples (Italy); Cuocolo, Alberto [Institute of Diagnostic and Nuclear Development, SDN Foundation, Naples (Italy); Federico II University of Naples, Division of Imaging, Radiotherapy, Neuroradiology, and Medical Physics, Department of Advanced Biomedical Sciences, Naples (Italy)

    2016-12-15

    Sympathetic nervous system (SNS) hyperactivity is a salient characteristic of chronic heart failure (HF) and contributes to the progression of the disease. Iodine-123 meta-iodobenzylguanidine ({sup 123}I-mIBG) imaging has been successfully used to assess cardiac SNS activity in HF patients and to predict prognosis. Importantly, SNS hyperactivity characterizes also physiological ageing, and there is conflicting evidence on cardiac {sup 123}I-mIBG uptake in healthy elderly subjects compared to adults. However, little data are available on the impact of ageing on cardiac sympathetic nerve activity assessed by {sup 123}I-mIBG scintigraphy, in patients with HF. We studied 180 HF patients (age = 66.1 ± 10.5 years [yrs]), left ventricular ejection fraction (LVEF = 30.6 ± 6.3 %) undergoing cardiac {sup 123}I-mIBG imaging. Early and late heart to mediastinum (H/M) ratios and washout rate were calculated in all patients. Demographic, clinical, and echocardiographic data were also collected. Our study population consisted of 53 patients aged >75 years (age = 77.7 ± 4.0 year), 67 patients aged 62-72 years (age = 67.9 ± 3.2 years) and 60 patients aged ≤61 year (age = 53.9 ± 5.6 years). In elderly patients, both early and late H/M ratios were significantly lower compared to younger patients (p < 0.05). By multivariate analysis, H/M ratios (both early and late) and washout rate were significantly correlated with LVEF and age. Our data indicate that, in a population of HF patients, there is an independent age-related effect on cardiac SNS innervation assessed by {sup 123}I-mIBG imaging. This finding suggests that cardiac {sup 123}I-mIBG uptake in patients with HF might be affected by patient age. (orig.)

  9. Clinical evaluation of carbon-11-phenylephrine: MAO-sensitive marker of cardiac sympathetic neurons.

    Science.gov (United States)

    Raffel, D M; Corbett, J R; del Rosario, R B; Gildersleeve, D L; Chiao, P C; Schwaiger, M; Wieland, D M

    1996-12-01

    The sympathomimetic drug phenylephrine recently has been labeled with 11C for use in PET studies of cardiac sympathetic innervation. Previous reports using isolated perfused rat heart models indicate that phenylephrine is metabolized by intraneuronal monoamine oxidase (MAO). This report compares the imaging characteristics, neuronal selectivity and kinetics of (-)-[11C]phenylephrine (PHEN) to the structurally similar but MAO-resistant analog (-)-[11C]-meta-hydroxyephedrine (HED), an established heart neuronal marker. Fourteen healthy volunteers were studied with PET and PHEN. Ten had paired studies with HED; four of the 10 were scanned a second time with each tracer after oral administration of desipramine, a selective neuronal transport blocker. Hemodynamic and electrocardiographic responses were monitored. Blood levels of intact radiotracer and radiolabeled metabolites were determined from venous blood samples taken during the PET study. Myocardial retention indices for both tracers were calculated. No hemodynamic or electrocardiographic effects were observed with either tracer. PHEN showed reduced myocardial retention at 50 min compared to HED; however, image quality and uniformity of distribution were comparable. PHEN cleared from myocardium with a mean half-time of 59 +/- 5 min, while myocardial levels of HED remained constant. PHEN metabolites appeared in the blood approximately three times faster than HED metabolites. Desipramine pretreatment markedly reduced (> 60%) myocardial retention of both PHEN and HED. PHEN provides PET images of human heart comparable in quality and uniformity to HED. Like HED, PHEN localizes in the sympathetic nerves of the heart. However, the more rapid efflux of PHEN, that is likely mediated by MAO, may provide information on the functional status of cardiac sympathetic neurons unobtainable with HED.

  10. Adrenergic innervation of the developing chick heart: neural crest ablations to produce sympathetically aneural hearts

    International Nuclear Information System (INIS)

    Kirby, M.; Stewart, D.

    1984-01-01

    Ablation of various regions of premigratory trunk neural crest which gives rise to the sympathetic trunks was used to remove sympathetic cardiac innervation. Neuronal uptake of [ 3 H]-norepinephrine was used as an index of neuronal development in the chick atrium. Following ablation of neural crest over somites 10-15 or 15-20, uptake was significantly decreased in the atrium at 16 and 17 days of development. Ablation of neural crest over somites 5-10 and 20-25 caused no decrease in [ 3 H]-norepinephrine uptake. Removal of neural crest over somites 5-25 or 10-20 caused approximately equal depletions of [ 3 H]-norepinephrine uptake in the atrium. Cardiac norepinephrine concentration was significantly depressed following ablation of neural crest over somites 5-25 but not over somites 10-20. Light-microscopic and histofluorescent preparations confirmed the absence of sympathetic trunks in the region of the normal origin of the sympathetic cardiac nerves following neural crest ablation over somites 10-20. The neural tube and dorsal root ganglia were damaged in the area of the neural-crest ablation; however, all of these structures were normal cranial and caudal to the lesioned area. Development of most of the embryos as well as the morphology of all of the hearts was normal following the lesion. These results indicate that it is possible to produce sympathetically aneural hearts by neural-crest ablation; however, sympathetic cardiac nerves account for an insignificant amount of cardiac norepinephrine

  11. High-intensity facial nerve lesions on T2-weighted images in chronic persistent facial nerve palsy

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, T. [Dept. of Radiology, Sendai City Hospital, Sendai (Japan); Dept. of Radiology, Tottori Univ. (Japan); Ishii, K. [Dept. of Radiology, Sendai City Hospital, Sendai (Japan); Okitsu, T. [Dept. of Otolaryngology, Sendai City Hospital (Japan); Ogawa, T. [Dept. of Radiology, Tottori Univ. (Japan); Okudera, T. [Dept. of Radiology, Research Inst. of Brain and Blood Vessels-Akita, Akita (Japan)

    2001-05-01

    Our aim was to estimate the value of MRI in detecting irreversibly paralysed facial nerves. We examined 95 consecutive patients with a facial nerve palsy (14 with a persistent palsy, and 81 with good recovery), using a 1.0 T unit, with T2-weighted and contrast-enhanced T1-weighted images. The geniculate ganglion and tympanic segment had gave high signal on T2-weighted images in the chronic stage of persistent palsy, but not in acute palsy. The enhancement pattern of the facial nerve in the chronic persistent facial nerve palsy is similar to that in the acute palsy with good recovery. These findings suggest that T2-weighted MRI can be used to show severely damaged facial nerves. (orig.)

  12. Nerve supply to the internal anal sphincter differs from that to the distal rectum: an immunohistochemical study of cadavers.

    Science.gov (United States)

    Kinugasa, Yusuke; Arakawa, Takashi; Murakami, Gen; Fujimiya, Mineko; Sugihara, Kenichi

    2014-04-01

    Fecal incontinence is a common problem after anal sphincter-preserving operations. The intersphincteric autonomic nerves supplying the internal anal sphincter (IAS) are formed by the union of: (1) nerve fibers from Auerbach's nerve plexus of the most distal part of the rectum and (2) the inferior rectal branches of the pelvic plexus (IRB-PX) running along the conjoint longitudinal muscle coat. The aim of the present study is to identify the detailed morphology of nerves to the IAS. The study comprised histological and immunohistochemical evaluations of paraffin-embedded sections from a large block of anal canal from the preserved 10 cadavers. The IRB-PX came from the superior aspect of the levator ani and ran into the anal canal on the anterolateral side. These nerves contained both sympathetic and parasympathetic fibers, but the sympathetic content was much higher than in nerves from the distal rectum. All intramural ganglion cells in the distal rectum were neuronal nitric oxide synthase-positive and tyrosine hydroxylase-negative and were restricted to above the squamous-columnar epithelial junction. Parasympathetic nerves formed a lattice-like plexus in the circular smooth muscles of the distal rectum, whereas the IAS contained short, longitudinally running sympathetic and parasympathetic nerves, although sympathetic nerves were dominant. The major autonomic nerve input to the IAS seemed not to originate from the distal rectum but from the IRB-PX. Injury to the IRB-PX during surgery seemed to result in loss of innervation to the major part of the IAS.

  13. Control of sympathetic vasomotor tone by catecholaminergic C1 neurones of the rostral ventrolateral medulla oblongata

    Science.gov (United States)

    Marina, Nephtali; Abdala, Ana P.L.; Korsak, Alla; Simms, Annabel E.; Allen, Andrew M.; Paton, Julian F.R.; Gourine, Alexander V.

    2011-01-01

    Aims Increased sympathetic tone in obstructive sleep apnoea results from recurrent episodes of systemic hypoxia and hypercapnia and might be an important contributor to the development of cardiovascular disease. In this study, we re-evaluated the role of a specific population of sympathoexcitatory catecholaminergic C1 neurones of the rostral ventrolateral medulla oblongata in the control of sympathetic vasomotor tone, arterial blood pressure, and hypercapnia-evoked sympathetic and cardiovascular responses. Methods and results In anaesthetized rats in vivo and perfused rat working heart brainstem preparations in situ, C1 neurones were acutely silenced by application of the insect peptide allatostatin following cell-specific targeting with a lentiviral vector to express the inhibitory Drosophila allatostatin receptor. In anaesthetized rats with denervated peripheral chemoreceptors, acute inhibition of 50% of the C1 neuronal population resulted in ∼50% reduction in renal sympathetic nerve activity and a profound fall in arterial blood pressure (by ∼25 mmHg). However, under these conditions systemic hypercapnia still evoked vigorous sympathetic activation and the slopes of the CO2-evoked sympathoexcitatory and cardiovascular responses were not affected by inhibition of C1 neurones. Inhibition of C1 neurones in situ resulted in a reversible fall in perfusion pressure and the amplitude of respiratory-related bursts of thoracic sympathetic nerve activity. Conclusion These data confirm a fundamental physiological role of medullary catecholaminergic C1 neurones in maintaining resting sympathetic vasomotor tone and arterial blood pressure. However, C1 neurones do not appear to mediate sympathoexcitation evoked by central actions of CO2. PMID:21543384

  14. Functional Nerve Preservation in Extracranial Head and Neck Schwannoma Surgery.

    Science.gov (United States)

    Ijichi, Kei; Kawakita, Daisuke; Maseki, Shinichiro; Beppu, Shintaro; Takano, Gaku; Murakami, Shingo

    2016-05-01

    A schwannoma is an uncommon, benign neurogenic tumor of Schwann cells. Tumor enucleation is the recommended surgical method to preserve function of the original nerve, although enucleation does not guarantee completely intact nerve function after the operation. To establish a strategy for functional preservation in extracranial head and neck schwannoma treatment by using an electromyographic (EMG) system during tumor resection. A retrospective cohort study was conducted of 15 patients who underwent surgery for removal of schwannoma tumors between April 1, 2006, and March 31, 2015, at an academic tertiary referral center. Data analysis was conducted from April 3, 2006, to September 15, 2015. Neurogenic tumors were diagnosed according to preoperative findings, and during surgery tumors were exposed and given EMG-controlled electrical stimulation to analyze their origins. In motor nerve cases, the electrical activity of the muscle was measured and recorded by EMG. The tumor was then enucleated by incision along tumor fibers mapped using EMG stimulation. If a nerve bundle was visible, we incised along there and enucleated the tumor. A strategy using electrical stimulation to improve preservation of nerve function in extracranial head and neck schwannoma operations. Frequency and duration of postoperative neurologic complications associated with functional preservation surgery with tumor enucleation was evaluated using EMG monitoring according to tumor origin. Of the 15 patients with extracranial schwannoma, 9 (60%) were women (mean [SD] age, 36.3 [15.3] years). All 15 patients underwent surgery using a transcervical approach. The most common nerves of origin were the vagus nerve and the sympathetic chain. In sensory or sympathetic nerve cases, the EMG response was absent. Two of 5 patients with vagus schwannoma had postoperative temporary vocal nerve palsy. These symptoms showed improvement after 1 year. There was no tumor recurrence during the follow-up period in any

  15. MR imaging evaluation of suprascapular nerve entrapment

    International Nuclear Information System (INIS)

    Ludig, T.; Walter, F.; Roland, J.; Blum, A.; Chapuis, D.; Mole, D.

    2001-01-01

    The aim of this study was to assess the significance of muscular edema, atrophy, and fatty changes in the diagnosis of suprascapular nerve entrapment (SSNE), and to confirm muscular edema as the most significant sign of neuropathy. A retrospective study of 18 patients with suprascapular nerve entrapment was performed. All patients underwent electromyographic studies and MR imaging with a 1.5-T Echo Speed system (General Electric, Milwaukee, Wis.). The diagnosis of muscle edema was reached when muscles presented a high signal on T2-weighted fast spin-echo (SE) fat-suppressed images. Muscular trophicity and fatty changes were analyzed on a sagittal oblique cut using SE T1-weighted images. Intra- and inter-observer reproducibility using kappa test, sensitivity, and specificity were analyzed, together with negative and positive predictive value of each criterion. The topographic diagnosis was correct as edema affected the infraspinatus muscle alone when the suprascapular nerve was entrapped at the spinoglenoid notch. Both the supraspinatus and infraspinatus muscles were affected when nerve was compressed at the suprascapular notch. Sensitivity and specificity of muscular edema were, respectively, 94.5 and 100%. Muscular atrophy sensitivity and specificity were 81 and 80%, respectively. Fatty changes sensitivity and specificity were 25 and 96%, respectively. Muscular edema seems to be a more sensitive sign of SSNE than muscle atrophy and fatty changes when compared with EMG results. Magnetic resonance imaging can reach a positive, topographic, and etiologic diagnosis of SSNE. (orig.)

  16. Tonic aortic depressor nerve stimulation does not impede baroreflex dynamic characteristics concomitantly mediated by the stimulated nerve.

    Science.gov (United States)

    Kawada, Toru; Turner, Michael J; Shimizu, Shuji; Kamiya, Atsunori; Shishido, Toshiaki; Sugimachi, Masaru

    2018-03-01

    Although electrical activation of the carotid sinus baroreflex (baroreflex activation therapy) is being explored as a device therapy for resistant hypertension, possible effects on baroreflex dynamic characteristics of interaction between electrical stimulation and pressure inputs are not fully elucidated. To examine whether the electrical stimulation of the baroreceptor afferent nerve impedes normal short-term arterial pressure (AP) regulation mediated by the stimulated nerve, we electrically stimulated the right aortic depressor nerve (ADN) while estimating the baroreflex dynamic characteristics by imposing pressure inputs to the isolated baroreceptor region of the right ADN in nine anesthetized rats. A Gaussian white noise signal with a mean of 120 mmHg and standard deviation of 20 mmHg was used for the pressure perturbation. A tonic ADN stimulation (2 or 5 Hz, 10 V, 0.1-ms pulse width) decreased mean sympathetic nerve activity (367.0 ± 70.9 vs. 247.3 ± 47.2 arbitrary units, P ADN stimulation did not affect the slope of dynamic gain in the neural arc transfer function from pressure perturbation to sympathetic nerve activity (16.9 ± 1.0 vs. 14.7 ± 1.6 dB/decade, not significant). These results indicate that electrical stimulation of the baroreceptor afferent nerve does not significantly impede the dynamic characteristics of the arterial baroreflex concomitantly mediated by the stimulated nerve. Short-term AP regulation by the arterial baroreflex may be preserved during the baroreflex activation therapy.

  17. MR imaging of nerve root impingement in the lumbar spine

    International Nuclear Information System (INIS)

    Teresi, L.M.; Bradley, W.G. Jr.; Bloze, A.E.; Davis, S.J.; Amster, J.; Berger, P.E.

    1990-01-01

    This paper determines the relationship between MR imaging findings of nerve root impingement, presenting symptoms, and physical examination findings, and physiologic data (DSEP and EMG) in a population of patients presented with classic radicular symptoms. Fifty-eight patients presenting with classic radicular pain were studied with MR imaging, DSER, and EMG, MR imaging was performed with a GE Signa imaging system with use of T1- and T2-weighted sequences and 5-mm-thick sections. Nerve root impingement in the subarticular recess (the root exiting the next lowest level) was distinguished from nerve root impingement in the superior intervertebral foramen (the root exiting the same level)

  18. Sympathetic, sensory, and nonneuronal contributions to the cutaneous vasoconstrictor response to local cooling.

    Science.gov (United States)

    Johnson, John M; Yen, Tony C; Zhao, Kun; Kosiba, Wojciech A

    2005-04-01

    Previous work indicates that sympathetic nerves participate in the vascular responses to direct cooling of the skin in humans. We evaluated this hypothesis further in a four-part series by measuring changes in cutaneous vascular conductance (CVC) from forearm skin locally cooled from 34 to 29 degrees C for 30 min. In part 1, bretylium tosylate reversed the initial vasoconstriction (-14 +/- 6.6% control CVC, first 5 min) to one of vasodilation (+19.7 +/- 7.7%) but did not affect the response at 30 min (-30.6 +/- 9% control, -38.9 +/- 6.9% bretylium; both P 0.05 between treatments). In part 2, yohimbine and propranolol (YP) also reversed the initial vasoconstriction (-14.3 +/- 4.2% control) to vasodilation (+26.3 +/- 12.1% YP), without a significant effect on the 30-min response (-26.7 +/- 6.1% YP, -43.2 +/- 6.5% control; both P 0.05 between sites). In part 3, the NPY Y1 receptor antagonist BIBP 3226 had no significant effect on either phase of vasoconstriction (P > 0.05 between sites both times). In part 4, sensory nerve blockade by anesthetic cream (Emla) also reversed the initial vasoconstriction (-20.1 +/- 6.4% control) to one of vasodilation (+213.4 +/- 87.0% Emla), whereas the final levels did not differ significantly (-37.7 +/- 10.1% control, -37.2 +/- 8.7% Emla; both P 0.05 between treatments). These results indicate that local cooling causes cold-sensitive afferents to activate sympathetic nerves to release norepinephrine, leading to a local cutaneous vasoconstriction that masks a nonneurogenic vasodilation. Later, a vasoconstriction develops with or without functional sensory or sympathetic nerves.

  19. Changes in the Skin Conductance Monitor as an End Point for Sympathetic Nerve Blocks.

    Science.gov (United States)

    Gungor, Semih; Rana, Bhumika; Fields, Kara; Bae, James J; Mount, Lauren; Buschiazzo, Valeria; Storm, Hanne

    2017-11-01

    There is a lack of objective methods for determining the achievement of sympathetic block. This study validates the skin conductance monitor (SCM) as an end point indicator of successful sympathetic blockade as compared with traditional monitors. This interventional study included 13 patients undergoing 25 lumbar sympathetic blocks to compare time to indication of successful blockade between the SCM indices and traditional measures, clinically visible hyperemia, clinically visible engorgement of veins, subjective skin temperature difference, unilateral thermometry monitoring, bilateral comparative thermometry monitoring, and change in waveform amplitude in pulse oximetry plethysmography, within a 30-minute observation period. Differences in the SCM indices were studied pre- and postblock to validate the SCM. SCM showed substantially greater odds of indicating achievement of sympathetic block in the next moment (i.e., hazard rate) compared with all traditional measures (clinically visible hyperemia, clinically visible engorgement of veins, subjective temperature difference, unilateral thermometry monitoring, bilateral comparative thermometry monitoring, and change in waveform amplitude in pulse oximetry plethysmography; P ≤ 0.011). SCM indicated successful block for all (100%) procedures, while the traditional measures failed to indicate successful blocks in 16-84% of procedures. The SCM indices were significantly higher in preblock compared with postblock measurements (P SCM is a more reliable and rapid response indicator of a successful sympathetic blockade when compared with traditional monitors. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  20. Potential Role of Semaphorin 3A and Its Receptors in Regulating Aberrant Sympathetic Innervation in Peritoneal and Deep Infiltrating Endometriosis.

    Science.gov (United States)

    Liang, Yanchun; Wang, Wei; Huang, Jiaming; Tan, Hao; Liu, Tianyu; Shang, Chunliang; Liu, Duo; Guo, Luyan; Yao, Shuzhong

    2015-01-01

    Previous studies have demonstrated the involvement of nerve repellent factors in regulation of the imbalanced innervation of endometriosis. This prospective study aims to explore the role of Sema 3A in regulating aberrant sympathetic innervation in peritoneal and deep infiltrating endometriosis. Ectopic endometriotic lesion were collected from patients with peritoneal endometriosis (n = 24) and deep infiltrating endometriosis of uterosacral ligament (n = 20) undergoing surgery for endometriosis. Eutopic endometrial samples were collected from patients with endometriosis (n = 22) or without endometriosis (n = 26). Healthy peritoneum (n = 13) from the lateral pelvic wall and healthy uterosacral ligament (n = 13) were obtained from patients who had no surgical and histological proof of endometriosis during hysterectomy for uterine fibroids. Firstly, we studied the immunostaining of Sema 3A, Plexin A1 and NRP-1 in all the tissues described above. Then we studied the nerve fiber density (NFD) of endometriosis-associated (sympathetic) nerve and para-endometriotic (sympathetic) nerve by double immunofluorescence staining. Finally we analyzed the relationship between expression of Sema 3A in stromal cells of endometriotic lesion and the aberrant innervation of endometriosis. Semi-quantitative immunostaining demonstrated that (1) Higher immunostaining of Sema 3A were found in the eutopic endometrial glandular epithelial cells from patients with endometriosis (p = 0.041) than those without endometriosis; (2) Sema 3A immunostaining was higher in glandular epithelial cells of peritoneal endometriosis (Pendometriosis, while its expression in ectopic stormal cells in both groups were significantly lower than that from eutopic endometrium of women without endometirosis (Pendometriosis-associated sympathetic nerve of peritoneal endometriosis (pendometriosis of uterosacral ligament (pperitoneal and deep infiltrating endometriosis.

  1. Potential Role of Semaphorin 3A and Its Receptors in Regulating Aberrant Sympathetic Innervation in Peritoneal and Deep Infiltrating Endometriosis

    Science.gov (United States)

    Liang, Yanchun; Wang, Wei; Huang, Jiaming; Tan, Hao; Liu, Tianyu; Shang, Chunliang; Liu, Duo; Guo, Luyan; Yao, Shuzhong

    2015-01-01

    Previous studies have demonstrated the involvement of nerve repellent factors in regulation of the imbalanced innervation of endometriosis. This prospective study aims to explore the role of Sema 3A in regulating aberrant sympathetic innervation in peritoneal and deep infiltrating endometriosis. Ectopic endometriotic lesion were collected from patients with peritoneal endometriosis (n = 24) and deep infiltrating endometriosis of uterosacral ligament (n = 20) undergoing surgery for endometriosis. Eutopic endometrial samples were collected from patients with endometriosis (n = 22) or without endometriosis (n = 26). Healthy peritoneum (n = 13) from the lateral pelvic wall and healthy uterosacral ligament (n = 13) were obtained from patients who had no surgical and histological proof of endometriosis during hysterectomy for uterine fibroids. Firstly, we studied the immunostaining of Sema 3A, Plexin A1 and NRP-1 in all the tissues described above. Then we studied the nerve fiber density (NFD) of endometriosis-associated (sympathetic) nerve and para-endometriotic (sympathetic) nerve by double immunofluorescence staining. Finally we analyzed the relationship between expression of Sema 3A in stromal cells of endometriotic lesion and the aberrant innervation of endometriosis. Semi-quantitative immunostaining demonstrated that (1) Higher immunostaining of Sema 3A were found in the eutopic endometrial glandular epithelial cells from patients with endometriosis (p = 0.041) than those without endometriosis; (2) Sema 3A immunostaining was higher in glandular epithelial cells of peritoneal endometriosis (Pendometriosis, while its expression in ectopic stormal cells in both groups were significantly lower than that from eutopic endometrium of women without endometirosis (Pendometriosis-associated sympathetic nerve of peritoneal endometriosis (pendometriosis of uterosacral ligament (pendometriosis. PMID:26720585

  2. Targeted NGF siRNA delivery attenuates sympathetic nerve sprouting and deteriorates cardiac dysfunction in rats with myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Hesheng Hu

    Full Text Available Nerve growth factor (NGF is involved in nerve sprouting, hyper-innervation, angiogenesis, anti-apoptosis, and preservation of cardiac function after myocardial infarction (MI. Positively modulating NGF expression may represent a novel pharmacological strategy to improve post-infarction prognosis. In this study, lentivirus encoding NGF short interfering RNA (siRNA was prepared, and MI was modeled in the rat using left anterior descending coronary artery ligation. Rats were randomly grouped to receive intramyocardial injection of lentiviral solution containing NGF-siRNA (n = 19, MI-SiNGF group, lentiviral solution containing empty vector (n = 18, MI-GFP group or 0.9% NaCl solution (n = 18, MI-control group, or to receive thoracotomy and pericardiotomy (n = 17, sham-operated group. At 1, 2, 4, and 8 wk after transduction, rats in the MI-control group had higher levels of NGF mRNA and protein than those in the sham-operated group, rats in the MI-GFP group showed similar levels as the MI-control group, and rats in the MI-SiNGF group had lower levels compared to the MI-GFP group, indicating that MI model was successfully established and NGF siRNA effectively inhibited the expression of NGF. At 8 wk, echocardiographic and hemodynamic studies revealed a more severe cardiac dysfunction in the MI-siRNA group compared to the MI-GFP group. Moreover, rats in the MI-siRNA group had lower mRNA and protein expression levels of tyrosine hydroxylase (TH and growth-associated protein 43-positive nerve fibers (GAP-43 at both the infarcted border and within the non-infarcted left ventricles (LV. NGF silencing also reduced the vascular endothelial growth factor (VEGF expression and decreased the arteriolar and capillary densities at the infarcted border compared to the MI-GFP group. Histological analysis indicated a large infarcted size in the MI-SiNGF group. These findings suggested that endogenous NGF silencing attenuated sympathetic nerve sprouting

  3. Sympathetic Overactivity in Chronic Kidney Disease: Consequences and Mechanisms

    Directory of Open Access Journals (Sweden)

    Jasdeep Kaur

    2017-08-01

    Full Text Available The incidence of chronic kidney disease (CKD is increasing worldwide, with more than 26 million people suffering from CKD in the United States alone. More patients with CKD die of cardiovascular complications than progress to dialysis. Over 80% of CKD patients have hypertension, which is associated with increased risk of cardiovascular morbidity and mortality. Another common, perhaps underappreciated, feature of CKD is an overactive sympathetic nervous system. This elevation in sympathetic nerve activity (SNA not only contributes to hypertension but also plays a detrimental role in the progression of CKD independent of any increase in blood pressure. Indeed, high SNA is associated with poor prognosis and increased cardiovascular morbidity and mortality independent of its effect on blood pressure. This brief review will discuss some of the consequences of sympathetic overactivity and highlight some of the potential pathways contributing to chronically elevated SNA in CKD. Mechanisms leading to chronic sympathoexcitation in CKD are complex, multifactorial and to date, not completely understood. Identification of the mechanisms and/or signals leading to sympathetic overactivity in CKD are crucial for development of effective therapeutic targets to reduce the increased cardiovascular risk in this patient group.

  4. NaCl and osmolarity produce different responses in organum vasculosum of the lamina terminalis neurons, sympathetic nerve activity and blood pressure.

    Science.gov (United States)

    Kinsman, Brian J; Browning, Kirsteen N; Stocker, Sean D

    2017-09-15

    Changes in extracellular osmolarity stimulate thirst and vasopressin secretion through a central osmoreceptor; however, central infusion of hypertonic NaCl produces a greater sympathoexcitatory and pressor response than infusion of hypertonic mannitol/sorbitol. Neurons in the organum vasculosum of the lamina terminalis (OVLT) sense changes in extracellular osmolarity and NaCl. In this study, we discovered that intracerebroventricular infusion or local OVLT injection of hypertonic NaCl increases lumbar sympathetic nerve activity, adrenal sympathetic nerve activity and arterial blood pressure whereas equi-osmotic mannitol/sorbitol did not alter any variable. In vitro whole-cell recordings demonstrate the majority of OVLT neurons are responsive to hypertonic NaCl or mannitol. However, hypertonic NaCl stimulates a greater increase in discharge frequency than equi-osmotic mannitol. Intracarotid or intracerebroventricular infusion of hypertonic NaCl evokes a greater increase in OVLT neuronal discharge frequency than equi-osmotic sorbitol. Collectively, these novel data suggest that subsets of OVLT neurons respond differently to hypertonic NaCl versus osmolarity and subsequently regulate body fluid homeostasis. These responses probably reflect distinct cellular mechanisms underlying NaCl- versus osmo-sensing. Systemic or central infusion of hypertonic NaCl and other osmolytes readily stimulate thirst and vasopressin secretion. In contrast, central infusion of hypertonic NaCl produces a greater increase in arterial blood pressure (ABP) than equi-osmotic mannitol/sorbitol. Although these responses depend on neurons in the organum vasculosum of the lamina terminalis (OVLT), these observations suggest OVLT neurons may sense or respond differently to hypertonic NaCl versus osmolarity. The purpose of this study was to test this hypothesis in Sprague-Dawley rats. First, intracerebroventricular (icv) infusion (5 μl/10 min) of 1.0 m NaCl produced a significantly greater

  5. Clinical application of l-123 MlBG cardiac imaging

    International Nuclear Information System (INIS)

    Kang, Do Young

    2004-01-01

    Cardiac neurotransmission imaging allows in vivo assessment of presynaptic reuptake, neurotransmitter storage and postsynaptic receptors. Among the various neurotransmitter, I-123 MlBG is most available and relatively well-established. Metaiodobenzylguanidine (MIBG) is an analogue of the false neurotransmitter guanethidine. It is taken up to adrenergic neurons by uptake-1 mechanism as same as norepinephrine. As tagged with I-123, it can be used to image sympathetic function in various organs including heart with planar or SPECT techniques. I-123 MIBG imaging has a unique advantage to evaluate myocardial neuronal activity in which the heart has no significant structural abnormality or even no functional derangement measured with other conventional examination. In patients with cardiomyopathy and heart failure, this imaging has most sensitive technique to predict prognosis and treatment response of betablocker or ACE inhibitor. In diabetic patients, it allow very early detection of autonomic neuropathy. In patients with dangerous arrhythmia such as ventricular tachycardia or fibrillation, MIBG imaging may be only an abnormal result among various exams. In patients with ischemic heart disease, sympathetic derangement may be used as the method of risk stratification. In heart transplanted patients, sympathetic reinnervation is well evaluated. Adriamycin-induced cardiotoxicity is detected earlier than ventricular dysfunction with sympathetic dysfunction. Neurodegenerative disorder such as Parkinson's disease or dementia with Lewy bodies has also cardiac sympathetic dysfunction. Noninvasive assessment of cardiac sympathetic nerve activity with l-123 MlBG imaging may be improve understanding of the pathophysiology of cardiac disease and make a contribution to predict survival and therapy efficacy

  6. Clinical application of l-123 MlBG cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young [College of Medicine, Donga Univ., Busan (Korea, Republic of)

    2004-10-01

    Cardiac neurotransmission imaging allows in vivo assessment of presynaptic reuptake, neurotransmitter storage and postsynaptic receptors. Among the various neurotransmitter, I-123 MlBG is most available and relatively well-established. Metaiodobenzylguanidine (MIBG) is an analogue of the false neurotransmitter guanethidine. It is taken up to adrenergic neurons by uptake-1 mechanism as same as norepinephrine. As tagged with I-123, it can be used to image sympathetic function in various organs including heart with planar or SPECT techniques. I-123 MIBG imaging has a unique advantage to evaluate myocardial neuronal activity in which the heart has no significant structural abnormality or even no functional derangement measured with other conventional examination. In patients with cardiomyopathy and heart failure, this imaging has most sensitive technique to predict prognosis and treatment response of betablocker or ACE inhibitor. In diabetic patients, it allow very early detection of autonomic neuropathy. In patients with dangerous arrhythmia such as ventricular tachycardia or fibrillation, MIBG imaging may be only an abnormal result among various exams. In patients with ischemic heart disease, sympathetic derangement may be used as the method of risk stratification. In heart transplanted patients, sympathetic reinnervation is well evaluated. Adriamycin-induced cardiotoxicity is detected earlier than ventricular dysfunction with sympathetic dysfunction. Neurodegenerative disorder such as Parkinson's disease or dementia with Lewy bodies has also cardiac sympathetic dysfunction. Noninvasive assessment of cardiac sympathetic nerve activity with l-123 MlBG imaging may be improve understanding of the pathophysiology of cardiac disease and make a contribution to predict survival and therapy efficacy.

  7. Sympathetic activation during early pregnancy in humans

    Science.gov (United States)

    Jarvis, Sara S; Shibata, Shigeki; Bivens, Tiffany B; Okada, Yoshiyuki; Casey, Brian M; Levine, Benjamin D; Fu, Qi

    2012-01-01

    Sympathetic activity has been reported to increase in normotensive pregnant women, and to be even greater in women with gestational hypertension and preeclampsia at term. Whether sympathetic overactivity develops early during pregnancy, remaining high throughout gestation, or whether it only occurs at term providing the substrate for hypertensive disorders is unknown. We tested the hypothesis that sympathetic activation occurs early during pregnancy in humans. Eleven healthy women (29 ± 3 (SD) years) without prior hypertensive pregnancies were tested during the mid-luteal phase (PRE) and early pregnancy (EARLY; 6.2 ± 1.2 weeks of gestation). Muscle sympathetic nerve activity (MSNA) and haemodynamics were measured supine, at 30 deg and 60 deg upright tilt for 5 min each. Blood samples were drawn for catecholamines, direct renin, and aldosterone. MSNA was significantly greater during EARLY than PRE (supine: 25 ± 8 vs. 14 ± 8 bursts min−1, 60 deg tilt: 49 ± 14 vs. 40 ± 10 bursts min−1; main effect, P < 0.05). Resting diastolic pressure trended lower (P = 0.09), heart rate was similar, total peripheral resistance decreased (2172 ± 364 vs. 2543 ± 352 dyne s cm−5; P < 0.05), sympathetic vascular transduction was blunted (0.10 ± 0.05 vs. 0.36 ± 0.47 units a.u.−1 min−1; P < 0.01), and both renin (supine: 27.9 ± 6.2 vs. 14.2 ± 8.7 pg ml−1, P < 0.01) and aldosterone (supine: 16.7 ± 14.1 vs. 7.7 ± 6.8 ng ml−1, P = 0.05) were higher during EARLY than PRE. These results suggest that sympathetic activation is a common characteristic of early pregnancy in humans despite reduced diastolic pressure and total peripheral resistance. These observations challenge conventional thinking about blood pressure regulation during pregnancy, showing marked sympathetic activation occurring within the first few weeks of conception, and may provide the substrate for pregnancy induced cardiovascular complications. PMID:22687610

  8. [Nerve growth factor and the physiology of pain: the relationships among interoception, sympathetic neurons and the emotional response indicated by the molecular pathophysiology of congenital insensitivity to pain with anhidrosis].

    Science.gov (United States)

    Indo, Yasuhiro

    2015-05-01

    Nerve growth factor (NGF) is a neurotrophic factor essential for the survival and maintenance of neurons. Congenital insensitivity to pain with anhidrosis (CIPA) is caused by loss-of-function mutations in NTRK1, which encodes a receptor tyrosine kinase, TrkA, for NGF. Mutations in NTRK1 cause the selective loss of NGF-dependent neurons, including both NGF-dependent primary afferents and sympathetic postganglionic neurons, in otherwise intact systems. The NGF-dependent primary afferents are thinly myelinated AΔ or unmyelinated C-fibers that are dependent on the NGF-TrkA system during development. NGF-dependent primary afferents are not only nociceptive neurons that transmit pain and temperature sensation, but also are polymodal receptors that play essential roles for interoception by monitoring various changes in the physiological status of all tissues in the body. In addition, they contribute to various inflammatory processes in acute, chronic and allergic inflammation. Together with sympathetic postganglionic neurons, they maintain the homeostasis of the body and emotional responses via interactions with the brain, immune and endocrine systems. Pain is closely related to emotions that accompany physical responses induced by systemic activation of the sympathetic nervous system. In contrast to a negative image of emotions in daily life, Antonio Damasio proposed the 'Somatic Marker Hypothesis', wherein emotions play critical roles in the decision-making and reasoning processes. According to this hypothesis, reciprocal communication between the brain and the body-proper are essential for emotional responses. Using the pathophysiology of CIPA as a foundation, this article suggests that NGF-dependent neurons constitute a part of the neuronal network required for homeostasis and emotional responses, and indicates that this network plays important roles in mediating the reciprocal communication between the brain and the body-proper.

  9. Anatomic Patterns of Renal Arterial Sympathetic Innervation: New Aspects for Renal Denervation.

    Science.gov (United States)

    Imnadze, Guram; Balzer, Stefan; Meyer, Baerbel; Neumann, Joerg; Krech, Rainer Horst; Thale, Joachim; Franz, Norbert; Warnecke, Henning; Awad, Khaled; Hayek, Salim S; Devireddy, Chandan

    2016-12-01

    Initial studies of catheter-based renal arterial sympathetic denervation to lower blood pressure in resistant hypertensive patients renewed interest in the sympathetic nervous system's role in the pathogenesis of hypertension. However, the SYMPLICITY HTN-3 study failed to meet its prespecified blood pressure lowering efficacy endpoint. To date, only a limited number of studies have described the microanatomy of renal nerves, of which, only two involve humans. Renal arteries were harvested from 15 cadavers from the Klinikum Osnabruck and Schuchtermann Klinik, Bad Rothenfelde. Each artery was divided longitudinally in equal thirds (proximal, middle, and distal), with each section then divided into equal superior, inferior, anterior, and posterior quadrants, which were then stained. Segments containing no renal nerves were given a score value = 0, 1-2 nerves with diameter 4 nerves or nerve diameter ≥600 µm a score = 3. A total of 22 renal arteries (9 right-sided, 13 left-sided) were suitable for examination. Overall, 691 sections of 5 mm thickness were prepared. Right renal arteries had significantly higher mean innervation grade (1.56 ± 0.85) compared to left renal arteries (1.09 ± 0.87) (P renal artery has significantly higher innervation scores than the left. The anterior and superior quadrants of the renal arteries scored higher in innervation than the posterior and inferior quadrants did. The distal third of the renal arteries are more innervated than the more proximal segments. These findings warrant further evaluation of the spatial innervation patterns of the renal artery in order to understand how it may enhance catheter-based renal arterial denervation procedural strategy and outcomes. The SYMPLICITY HTN-3 study dealt a blow to the idea of the catheter-based renal arterial sympathetic denervation. We investigated the location and patterns of periarterial renal nerves in cadaveric human renal arteries. To quantify the density of the

  10. Sympathetic ingrowth: A result of cholinergic nerve injury in the adult mammalian brain

    International Nuclear Information System (INIS)

    Davis, J.N.

    1986-01-01

    This paper describes sympathetic ingrowth, its regulation and function. The study leads to a better understanding of the molecular mechanisms that probably underlie the regulation of other neuronal rearrangements. The authors examine tritium-2-deoxyglucose uptake in the hippocampal formation after septal leasions. Preliminary experiments suggest that the septo-hippocampal fibers do influence tritium-2-deoxyglucose uptake throughout the hippocampal formation in normal animals. If sympathetic ingrowth also can influence this uptake, this could provide further evidence for an adaptive role of this noradrenergic replacement of cholinergic neurons

  11. Imaging of muscular denervation secondary to motor cranial nerve dysfunction

    International Nuclear Information System (INIS)

    Connor, S.E.J.; Chaudhary, N.; Fareedi, S.; Woo, E.K.

    2006-01-01

    The effects of motor cranial nerve dysfunction on the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of head and neck muscles are reviewed. Patterns of denervation changes are described and illustrated for V, VII, X, XI and XII cranial nerves. Recognition of the range of imaging manifestations, including the temporal changes in muscular appearances and associated muscular grafting or compensatory hypertrophy, will avoid misinterpretation as local disease. It will also prompt the radiologist to search for underlying cranial nerve pathology, which may be clinically occult. The relevant cranial nerve motor division anatomy will be described to enable a focussed search for such a structural abnormality

  12. Imaging of muscular denervation secondary to motor cranial nerve dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Connor, S.E.J. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom)]. E-mail: sejconnor@tiscali.co.uk; Chaudhary, N. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Fareedi, S. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Woo, E.K. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom)

    2006-08-15

    The effects of motor cranial nerve dysfunction on the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of head and neck muscles are reviewed. Patterns of denervation changes are described and illustrated for V, VII, X, XI and XII cranial nerves. Recognition of the range of imaging manifestations, including the temporal changes in muscular appearances and associated muscular grafting or compensatory hypertrophy, will avoid misinterpretation as local disease. It will also prompt the radiologist to search for underlying cranial nerve pathology, which may be clinically occult. The relevant cranial nerve motor division anatomy will be described to enable a focussed search for such a structural abnormality.

  13. Optic Nerve Assessment Using 7-Tesla Magnetic Resonance Imaging.

    Science.gov (United States)

    Singh, Arun D; Platt, Sean M; Lystad, Lisa; Lowe, Mark; Oh, Sehong; Jones, Stephen E; Alzahrani, Yahya; Plesec, Thomas

    2016-04-01

    The purpose of this study was to correlate high-resolution magnetic resonance imaging (MRI) and histologic findings in a case of juxtapapillary choroidal melanoma with clinical evidence of optic nerve invasion. With institutional review board approval, an enucleated globe with choroidal melanoma and optic nerve invasion was imaged using a 7-tesla MRI followed by histopathologic evaluation. Optical coherence tomography, B-scan ultrasonography, and 1.5-tesla MRI of the orbit (1-mm sections) could not detect optic disc invasion. Ex vivo, 7-tesla MRI detected optic nerve invasion, which correlated with histopathologic features. Our case demonstrates the potential to document the existence of optic nerve invasion in the presence of an intraocular tumor, a feature that has a major bearing on decision making, particularly for consideration of enucleation.

  14. Cranial nerve contrast using nerve-specific fluorophores improved by paired-agent imaging with indocyanine green as a control agent

    Science.gov (United States)

    Torres, Veronica C.; Vuong, Victoria D.; Wilson, Todd; Wewel, Joshua; Byrne, Richard W.; Tichauer, Kenneth M.

    2017-09-01

    Nerve preservation during surgery is critical because damage can result in significant morbidity. This remains a challenge especially for skull base surgeries where cranial nerves (CNs) are involved because visualization and access are particularly poor in that location. We present a paired-agent imaging method to enhance identification of CNs using nerve-specific fluorophores. Two myelin-targeting imaging agents were evaluated, Oxazine 4 and Rhodamine 800, and coadministered with a control agent, indocyanine green, either intravenously or topically in rats. Fluorescence imaging was performed on excised brains ex vivo, and nerve contrast was evaluated via paired-agent ratiometric data analysis. Although contrast was improved among all experimental groups using paired-agent imaging compared to conventional, solely targeted imaging, Oxazine 4 applied directly exhibited the greatest enhancement, with a minimum 3 times improvement in CNs delineation. This work highlights the importance of accounting for nonspecific signal of targeted agents, and demonstrates that paired-agent imaging is one method capable of doing so. Although staining, rinsing, and imaging protocols need to be optimized, these findings serve as a demonstration for the potential use of paired-agent imaging to improve contrast of CNs, and consequently, surgical outcome.

  15. Effect of sympathetic activity on capsaicin-evoked pain, hyperalgesia, and vasodilatation.

    Science.gov (United States)

    Baron, R; Wasner, G; Borgstedt, R; Hastedt, E; Schulte, H; Binder, A; Kopper, F; Rowbotham, M; Levine, J D; Fields, H L

    1999-03-23

    Painful nerve and tissue injuries can be exacerbated by activity in sympathetic neurons. The mechanisms of sympathetically maintained pain (SMP) are unclear. To determine the effect of cutaneous sympathetic activity on pain induced by primary afferent C-nociceptor sensitization with capsaicin in humans. In healthy volunteers capsaicin was applied topically (n = 12) or injected into the forearm skin (n = 10) to induce spontaneous pain, dynamic and punctate mechanical hyperalgesia, and antidromic (axon reflex) vasodilatation (flare). Intensity of pain and hyperalgesia, axon reflex vasodilatation (laser Doppler), and flare size and area of hyperalgesia (planimetry) were assessed. The local skin temperature at the application and measurement sites was kept constant at 35 degrees C. In each individual the analyses were performed during the presence of high and low sympathetic skin activity induced by whole-body cooling and warming with a thermal suit. By this method sympathetic vasoconstrictor activity is modulated in the widest range that can be achieved physiologically. The degree of vasoconstrictor discharge was monitored by measuring skin blood flow (laser Doppler) and temperature (infrared thermometry) at the index finger. The intensity and spatial distribution of capsaicin-evoked spontaneous pain and dynamic and punctate mechanical hyperalgesia were identical during the presence of high and low sympathetic discharge. Antidromic vasodilatation and flare size were significantly diminished when sympathetic vasoconstrictor neurons were excited. Cutaneous sympathetic vasoconstrictor activity does not influence spontaneous pain and mechanical hyperalgesia after capsaicin-induced C-nociceptor sensitization. When using physiologic stimulation of sympathetic activity, the capsaicin model is not useful for elucidating mechanisms of SMP. In neuropathic pain states with SMP, different mechanisms may be present.

  16. Inhibition of facilitation of sympathetic neurotransmission and angiotensin II-induced pressor effects in the pithed rat: comparison between valsartan, candesartan, eprosartan and embusartan

    NARCIS (Netherlands)

    Balt, J. C.; Mathy, M. J.; Pfaffendorf, M.; van Zwieten, P. A.

    2001-01-01

    In the pithed rat model, endogenously generated angiotensin (Ang) II can enhance sympathetic neurotransmission by acting on Ang II type 1 (AT1) receptors that are located on sympathetic nerve terminals. To compare the inhibitory potency of candesartan, valsartan, eprosartan and embusartan in

  17. Sympathetically maintained pain presenting first as temporomandibular disorder, then as parotid dysfunction.

    Science.gov (United States)

    Giri, Subha; Nixdorf, Donald

    2007-03-01

    Complex regional pain syndrome (CRPS) is a chronic condition characterized by intense pain, swelling, redness, hypersensitivity and additional sudomotor effects. In all 13 cases of CRPS in the head and neck region reported in the literature, nerve injury was identified as the etiology for pain initiation. In this article, we present the case of a 30-year-old female patient with sympathetically maintained pain without apparent nerve injury. Her main symptoms--left-side preauricular pain and inability to open her mouth wide--mimicked temporomandibular joint arthralgia and myofascial pain of the masticatory muscles. Later, symptoms of intermittent preauricular pain and swelling developed, along with hyposalivation, which mimicked parotitis. After an extensive diagnostic process, no definitive underlying pathology could be identified and a diagnosis of neuropathic pain with a prominent sympathetic component was made. Two years after the onset of symptoms and initiation of care, treatment with repeated stellate ganglion blocks and enteral clonidine pharmacotherapy provided adequate pain relief.

  18. CT and MR imaging of the normal and pathologic conditions of the facial nerve

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Lorenz E-mail: jaeger@ikra.med.uni-muenchen.de; Reiser, Maximilian

    2001-11-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are well established imaging modalities to examine the facial nerve as well as the course of the facial nerve itself. High spatial resolution is guaranteed not only in the x- and y-axis, but also in the z-axis using multislice spiral CT. With this technique, reformatted multiplanar images in oblique planes, avoiding additional examinations in the coronal plane, facilitate the delineation of the facial nerve canal. This is beneficial in patients with temporal bone trauma, malformation or osseous changes. MR has a superior soft-tissue contrast to CT that enables imaging of the facial nerve itself. Therefore the normal facial nerve as well as pathologic changes of the facial nerve is readily visualized from the brain stem to the parotid gland. This review article presents anatomy, pathology and imaging strategies in the diagnostics of the facial nerve.

  19. Usefulness of cardiac 123I-MIBG imaging for the evaluation of diastolic heart failure

    International Nuclear Information System (INIS)

    Tanaka, Haruki; Kozai, Toshiyuki; Urabe, Yoshitoshi

    2007-01-01

    Significance of 123 I-MIBG (metaiodobenzylguanidine) scintigraphy in diagnosis of cardiac sympathetic nerve function is not yet elucidated in chronic heart failure derived from left ventricular diastolic defect despite its established importance in evaluation of severity and prognosis of chronic systolic heart failure. This study was performed to elucidate the usefulness of the imaging for chronic diastolic heart failure. Comparison was made of 47 hospitalized patients with chronic diastolic heart failure (D-group; left ejection fraction, 50% or more), 45 with chronic systolic failure (S-group; the fraction 123 I-MIBG with 2-detector gamma camera (Toshiba E.CAM), of which images were analyzed by Toshiba GMS-7000. Cardiac sympathetic nerve function in D-group was found stimulated to be impaired, in a similar extent to that in S-group; severity in NYHA classification was significantly correlated with late H/M ratio and WR; WR in cases with atrial fibrillation complication showed a significant correlation with plasma BNP level; and 123 I-MIBG scintigraphic evaluation of the nerve function in D-group was concluded to be useful for severity assessment. (T.I.)

  20. Origins of the sympathetic innervation to the nasal-associated lymphoid tissue (NALT): an anatomical substrate for a neuroimmune connection.

    Science.gov (United States)

    Marafetti, Lucas E; Romeo, Horacio E

    2014-11-15

    The participation of sympathetic nerve fibers in the innervation of the nasal-associated lymphoid tissues (NALT) was investigated in hamsters. Vesicular monoamine transporter 2 (VMAT2), an established sympathetic marker, is expressed in all neurons of superior cervical ganglia (SCG). In addition, VMAT2 -immunoreactive nerve fibers were localized in the NALT as well as in adjacent anatomical structures of the upper respiratory tract. Unilateral surgical ablation of the SCG abolished VMAT2 innervation patterns ipsilaterally while the contra lateral side is unaffected. These results provide the anatomical substrate for a neuroimmune connection in the NALT. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Changes in lumbosacral spinal nerve roots on diffusion tensor imaging in spinal stenosis

    Directory of Open Access Journals (Sweden)

    Zhong-jun Hou

    2015-01-01

    Full Text Available Lumbosacral degenerative disc disease is a common cause of lower back and leg pain. Conventional T1-weighted imaging (T1WI and T2-weighted imaging (T2WI scans are commonly used to image spinal cord degeneration. However, these modalities are unable to image the entire lumbosacral spinal nerve roots. Thus, in the present study, we assessed the potential of diffusion tensor imaging (DTI for quantitative assessment of compressed lumbosacral spinal nerve roots. Subjects were 20 young healthy volunteers and 31 patients with lumbosacral stenosis. T2WI showed that the residual dural sac area was less than two-thirds that of the corresponding normal area in patients from L 3 to S 1 stenosis. On T1WI and T2WI, 74 lumbosacral spinal nerve roots from 31 patients showed compression changes. DTI showed thinning and distortion in 36 lumbosacral spinal nerve roots (49% and abruption in 17 lumbosacral spinal nerve roots (23%. Moreover, fractional anisotropy values were reduced in the lumbosacral spinal nerve roots of patients with lumbosacral stenosis. These findings suggest that DTI can objectively and quantitatively evaluate the severity of lumbosacral spinal nerve root compression.

  2. Changes in lumbosacral spinal nerve roots on diffusion tensor imaging in spinal stenosis.

    Science.gov (United States)

    Hou, Zhong-Jun; Huang, Yong; Fan, Zi-Wen; Li, Xin-Chun; Cao, Bing-Yi

    2015-11-01

    Lumbosacral degenerative disc disease is a common cause of lower back and leg pain. Conventional T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI) scans are commonly used to image spinal cord degeneration. However, these modalities are unable to image the entire lumbosacral spinal nerve roots. Thus, in the present study, we assessed the potential of diffusion tensor imaging (DTI) for quantitative assessment of compressed lumbosacral spinal nerve roots. Subjects were 20 young healthy volunteers and 31 patients with lumbosacral stenosis. T2WI showed that the residual dural sac area was less than two-thirds that of the corresponding normal area in patients from L3 to S1 stenosis. On T1WI and T2WI, 74 lumbosacral spinal nerve roots from 31 patients showed compression changes. DTI showed thinning and distortion in 36 lumbosacral spinal nerve roots (49%) and abruption in 17 lumbosacral spinal nerve roots (23%). Moreover, fractional anisotropy values were reduced in the lumbosacral spinal nerve roots of patients with lumbosacral stenosis. These findings suggest that DTI can objectively and quantitatively evaluate the severity of lumbosacral spinal nerve root compression.

  3. Enhancement of nerve structure segmentation by a correntropy-based pre-image approach

    Directory of Open Access Journals (Sweden)

    J. Gil-González

    2017-05-01

    Full Text Available Peripheral Nerve Blocking (PNB is a commonly used technique for performing regional anesthesia and managing pain. PNB comprises the administration of anesthetics in the proximity of a nerve. In this sense, the success of PNB procedures depends on an accurate location of the target nerve. Recently, ultrasound images (UI have been widely used to locate nerve structures for PNB, since they enable a noninvasive visualization of the target nerve and the anatomical structures around it. However, UI are affected by speckle noise, which makes it difficult to accurately locate a given nerve. Thus, it is necessary to perform a filtering step to attenuate the speckle noise without eliminating relevant anatomical details that are required for high-level tasks, such as segmentation of nerve structures. In this paper, we propose an UI improvement strategy with the use of a pre-image-based filter. In particular, we map the input images by a nonlinear function (kernel. Specifically, we employ a correntropybased mapping as kernel functional to code higher-order statistics of the input data under both nonlinear and non-Gaussian conditions. We validate our approach against an UI dataset focused on nerve segmentation for PNB. Likewise, our Correntropy-based Pre-Image Filtering (CPIF is applied as a pre-processing stage to segment nerve structures in a UI. The segmentation performance is measured in terms of the Dice coefficient. According to the results, we observe that CPIF finds a suitable approximation for UI by highlighting discriminative nerve patterns.

  4. Facial Nerve Paralysis due to a Pleomorphic Adenoma with the Imaging Characteristics of a Facial Nerve Schwannoma

    OpenAIRE

    Nader, Marc-Elie; Bell, Diana; Sturgis, Erich M.; Ginsberg, Lawrence E.; Gidley, Paul W.

    2014-01-01

    Background Facial nerve paralysis in a patient with a salivary gland mass usually denotes malignancy. However, facial paralysis can also be caused by benign salivary gland tumors. Methods We present a case of facial nerve paralysis due to a benign salivary gland tumor that had the imaging characteristics of an intraparotid facial nerve schwannoma. Results The patient presented to our clinic 4 years after the onset of facial nerve paralysis initially diagnosed as Bell palsy. Computed tomograph...

  5. Diabetic peripheral neuropathy assessment through texture based analysis of corneal nerve images

    Science.gov (United States)

    Silva, Susana F.; Gouveia, Sofia; Gomes, Leonor; Negrão, Luís; João Quadrado, Maria; Domingues, José Paulo; Morgado, António Miguel

    2015-05-01

    Diabetic peripheral neuropathy (DPN) is one common complication of diabetes. Early diagnosis of DPN often fails due to the non-availability of a simple, reliable, non-invasive method. Several published studies show that corneal confocal microscopy (CCM) can identify small nerve fibre damage and quantify the severity of DPN, using nerve morphometric parameters. Here, we used image texture features, extracted from corneal sub-basal nerve plexus images, obtained in vivo by CCM, to identify DPN patients, using classification techniques. A SVM classifier using image texture features was used to identify (DPN vs. No DPN) DPN patients. The accuracies were 80.6%, when excluding diabetic patients without neuropathy, and 73.5%, when including diabetic patients without diabetic neuropathy jointly with healthy controls. The results suggest that texture analysis might be used as a complementing technique for DPN diagnosis, without requiring nerve segmentation in CCM images. The results also suggest that this technique has enough sensitivity to detect early disorders in the corneal nerves of diabetic patients.

  6. The role of the renal afferent and efferent nerve fibres in heart failure

    Directory of Open Access Journals (Sweden)

    Lindsea C Booth

    2015-10-01

    Full Text Available Renal nerves contain afferent, sensory and efferent, sympathetic nerve fibres. In heart failure (HF there is an increase in renal sympathetic nerve activity, which can lead to renal vasoconstriction, increased renin release and sodium retention. These changes are thought to contribute to renal dysfunction, which is predictive of poor outcome in patients with HF. In contrast, the role of the renal afferent nerves remains largely unexplored in HF. This is somewhat surprising as there are multiple triggers in HF that have the potential to increase afferent nerve activity, including increased venous pressure and reduced kidney perfusion. Some of the few studies investigating renal afferents in HF have suggested that at least the sympatho-inhibitory reno-renal reflex is blunted. In experimentally induced HF, renal denervation, both surgical and catheter-based, has been associated with some improvements in renal and cardiac function. It remains unknown whether the effects are due to removal of the efferent renal nerve fibres, afferent renal nerve fibres, or a combination of both. Here, we review the effects of HF on renal efferent and afferent nerve function and critically assess the latest evidence supporting renal denervation as a potential treatment in HF.

  7. The role of the renal afferent and efferent nerve fibers in heart failure

    Science.gov (United States)

    Booth, Lindsea C.; May, Clive N.; Yao, Song T.

    2015-01-01

    Renal nerves contain afferent, sensory and efferent, sympathetic nerve fibers. In heart failure (HF) there is an increase in renal sympathetic nerve activity (RSNA), which can lead to renal vasoconstriction, increased renin release and sodium retention. These changes are thought to contribute to renal dysfunction, which is predictive of poor outcome in patients with HF. In contrast, the role of the renal afferent nerves remains largely unexplored in HF. This is somewhat surprising as there are multiple triggers in HF that have the potential to increase afferent nerve activity, including increased venous pressure and reduced kidney perfusion. Some of the few studies investigating renal afferents in HF have suggested that at least the sympatho-inhibitory reno-renal reflex is blunted. In experimentally induced HF, renal denervation, both surgical and catheter-based, has been associated with some improvements in renal and cardiac function. It remains unknown whether the effects are due to removal of the efferent renal nerve fibers or afferent renal nerve fibers, or a combination of both. Here, we review the effects of HF on renal efferent and afferent nerve function and critically assess the latest evidence supporting renal denervation as a potential treatment in HF. PMID:26483699

  8. The cisternal segment of the abducens nerve in man: three-dimensional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, Alpay E-mail: aalkan@inonu.edu.tr; Sigirci, Ahmet; Ozveren, M. Faik; Kutlu, Ramazan; Altinok, Tayfun; Onal, Cagatay; Sarac, Kaya

    2004-09-01

    Purpose: The goal of this study was to identify the abducens nerve in its cisternal segment by using three-dimensional turbo spin echo T2-weighted image (3DT2-TSE). The abducens nerve may arise from the medullopontine sulcus by one singular or two separated rootlets. Material and methods: We studied 285 patients (150 males, 135 females, age range: 9-72 years, mean age: 33.3{+-}14.4) referred to MR imaging of the inner ear, internal auditory canal and brainstem. All 3D T2-TSE studies were performed with a 1.5 T MR system. Imaging parameters used for 3DT2-TSE sequence were TR:4000, TE:150, and 0.70 mm slice thickness. A field of view of 160 mm and 256x256 matrix were used. The double rootlets of the abducens nerve and contralateral abducens nerves and their relationships with anatomical structures were searched in the subarachnoid space. Results: We identified 540 of 570 abducens nerves (94.7%) in its complete cisternal course with certainty. Seventy-two cases (25.2%) in the present study had double rootlets of the abducens nerve. In 59 of these cases (34 on the right side and 25 on the left) presented with unilateral double rootlets of the abducens. Thirteen cases presented with bilateral double rootlets of the abducens (4.5%). Conclusion: An abducens nerve arising by two separate rootlets is not a rare variation. The detection of this anatomical variation by preoperative MR imaging is important to avoid partial damage of the nerve during surgical procedures. The 3DT2-TSE as a noninvasive technique makes it possible to obtain extremely high-quality images of microstructures as cranial nerves and surrounding vessels in the cerebellopontine cistern. Therefore, preoperative MR imaging should be performed to detect anatomical variations of abducens nerve and to reduce the chance of operative injuries.

  9. Artifacts produced during electrical stimulation of the vestibular nerve in cats. [autonomic nervous system components of motion sickness

    Science.gov (United States)

    Tang, P. C.

    1973-01-01

    Evidence is presented to indicate that evoked potentials in the recurrent laryngeal, the cervical sympathetic, and the phrenic nerve, commonly reported as being elicited by vestibular nerve stimulation, may be due to stimulation of structures other than the vestibular nerve. Experiments carried out in decerebrated cats indicated that stimulation of the petrous bone and not that of the vestibular nerve is responsible for the genesis of evoked potentials in the recurrent laryngeal and the cervical sympathetic nerves. The phrenic response to electrical stimulation applied through bipolar straight electrodes appears to be the result of stimulation of the facial nerve in the facial canal by current spread along the petrous bone, since stimulation of the suspended facial nerve evoked potentials only in the phrenic nerve and not in the recurrent laryngeal nerve. These findings indicate that autonomic components of motion sickness represent the secondary reactions and not the primary responses to vestibular stimulation.

  10. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica.

    Science.gov (United States)

    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang

    2015-04-01

    To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5-S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3-S1 nerve roots. ROC analysis was performed for FA values. The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Imaging the cranial nerves: Part I: Methodology, infectious and inflammatory, traumatic and congenital lesions

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil- Centro de Lisboa, Department of Radiology, Lisboa Codex (Portugal); Casselman, Jan [A.Z. St. Jan Brugge Hospital, Department of Radiology, Brugge (Belgium); A.Z. St. Augustinus Antwerpen Hospitals, Department of Radiology, Antwerpen (Belgium)

    2007-08-15

    Many disease processes manifest either primarily or secondarily by cranial nerve deficits. Neurologists, ENT surgeons, ophthalmologists and maxillo-facial surgeons are often confronted with patients with symptoms and signs of cranial nerve dysfunction. Seeking the cause of this dysfunction is a common indication for imaging. In recent decades we have witnessed an unprecedented improvement in imaging techniques, allowing direct visualization of increasingly small anatomic structures. The emergence of volumetric CT scanners, higher field MR scanners in clinical practice and higher resolution MR sequences has made a tremendous contribution to the development of cranial nerve imaging. The use of surface coils and parallel imaging allows sub-millimetric visualization of nerve branches and volumetric 3D imaging. Both with CT and MR, multiplanar and curved reconstructions can follow the entire course of a cranial nerve or branch, improving tremendously our diagnostic yield of neural pathology. This review article will focus on the contribution of current imaging techniques in the depiction of normal anatomy and on infectious and inflammatory, traumatic and congenital pathology affecting the cranial nerves. A detailed discussion of individual cranial nerves lesions is beyond the scope of this article. (orig.)

  12. Imaging the cranial nerves: Part I: Methodology, infectious and inflammatory, traumatic and congenital lesions

    International Nuclear Information System (INIS)

    Borges, Alexandra; Casselman, Jan

    2007-01-01

    Many disease processes manifest either primarily or secondarily by cranial nerve deficits. Neurologists, ENT surgeons, ophthalmologists and maxillo-facial surgeons are often confronted with patients with symptoms and signs of cranial nerve dysfunction. Seeking the cause of this dysfunction is a common indication for imaging. In recent decades we have witnessed an unprecedented improvement in imaging techniques, allowing direct visualization of increasingly small anatomic structures. The emergence of volumetric CT scanners, higher field MR scanners in clinical practice and higher resolution MR sequences has made a tremendous contribution to the development of cranial nerve imaging. The use of surface coils and parallel imaging allows sub-millimetric visualization of nerve branches and volumetric 3D imaging. Both with CT and MR, multiplanar and curved reconstructions can follow the entire course of a cranial nerve or branch, improving tremendously our diagnostic yield of neural pathology. This review article will focus on the contribution of current imaging techniques in the depiction of normal anatomy and on infectious and inflammatory, traumatic and congenital pathology affecting the cranial nerves. A detailed discussion of individual cranial nerves lesions is beyond the scope of this article. (orig.)

  13. Effects of perindopril on cardiac sympathetic nerve activity in patients with congestive heart failure: comparison with enalapril

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu; Toyama, Takuji; Suzuki, Tadashi; Kurabayashi, Masahiko [Gunma University School of Medicine, Department of Cardiovascular Medicine, Maebashi, Gunma (Japan); Kumakura, Hisao; Takayama, Yoshiaki; Ichikawa, Shuichi [Cardiovascular Hospital of Central Japan, Department of Internal Medicine, Gunma (Japan)

    2005-08-01

    The production of aldosterone in the heart is suppressed by the angiotensin-converting enzyme (ACE) inhibitor perindopril in patients with congestive heart failure (CHF). Moreover, perindopril has been reported to have more cardioprotective effects than enalapril. Forty patients with CHF [left ventricular ejection fraction (LVEF) <45%; mean 33{+-}7%] were randomly assigned to perindopril (2 mg/day; n=20) or enalapril (5 mg/day; n=20). All patients were also treated with diuretics. The delayed heart/mediastinum count (H/M) ratio, delayed total defect score (TDS) and washout rate (WR) were determined from {sup 123}I-meta-iodobenzylguanidine (MIBG) images, and plasma brain natriuretic peptide (BNP) concentrations were measured before and 6 months after treatment. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and LVEF were also determined by echocardiography. After treatment, in patients receiving perindopril, TDS decreased from 39{+-}10 to 34{+-}9 (P<0.01), H/M ratios increased from 1.62{+-}0.27 to 1.76{+-}0.29 (P<0.01), WR decreased from 50{+-}14% to 42{+-}14% (P<0.05) and plasma BNP concentrations decreased from 226{+-}155 to 141{+-}90 pg/ml (P<0.0005). In addition, the LVEDV decreased from 180{+-}30 to 161{+-}30 ml (P<0.05) and the LVESV decreased from 122{+-}35 to 105{+-}36 ml (P<0.05). Although the LVEF tended to increase, the change was not statistically significant (from 33{+-}8% to 36{+-}12%; P=NS). On the other hand, there were no significant changes in these parameters in patients receiving enalapril. Plasma BNP concentrations, {sup 123}I-MIBG scintigraphic and echocardiographic parameters improved after 6 months of perindopril treatment. These findings indicate that perindopril treatment can ameliorate the cardiac sympathetic nerve activity and the left ventricular performance in patients with CHF. (orig.)

  14. Anatomy of the nerves and ganglia of the aortic plexus in males

    Science.gov (United States)

    Beveridge, Tyler S; Johnson, Marjorie; Power, Adam; Power, Nicholas E; Allman, Brian L

    2015-01-01

    It is well accepted that the aortic plexus is a network of pre- and post-ganglionic nerves overlying the abdominal aorta, which is primarily involved with the sympathetic innervation to the mesenteric, pelvic and urogenital organs. Because a comprehensive anatomical description of the aortic plexus and its connections with adjacent plexuses are lacking, these delicate structures are prone to unintended damage during abdominal surgeries. Through dissection of fresh, frozen human cadavers (n = 7), the present study aimed to provide the first complete mapping of the nerves and ganglia of the aortic plexus in males. Using standard histochemical procedures, ganglia of the aortic plexus were verified through microscopic analysis using haematoxylin & eosin (H&E) and anti-tyrosine hydroxylase stains. All specimens exhibited four distinct sympathetic ganglia within the aortic plexus: the right and left spermatic ganglia, the inferior mesenteric ganglion and one previously unidentified ganglion, which has been named the prehypogastric ganglion by the authors. The spermatic ganglia were consistently supplied by the L1 lumbar splanchnic nerves and the inferior mesenteric ganglion and the newly characterized prehypogastric ganglion were supplied by the left and right L2 lumbar splanchnic nerves, respectively. Additionally, our examination revealed the aortic plexus does have potential for variation, primarily in the possibility of exhibiting accessory splanchnic nerves. Clinically, our results could have significant implications for preserving fertility in men as well as sympathetic function to the hindgut and pelvis during retroperitoneal surgeries. PMID:25382240

  15. Separate neurochemical classes of sympathetic postganglionic neurons project to the left ventricle of the rat heart.

    Science.gov (United States)

    Richardson, R J; Grkovic, I; Allen, A M; Anderson, C R

    2006-04-01

    The sympathetic innervation of the rat heart was investigated by retrograde neuronal tracing and multiple label immunohistochemistry. Injections of Fast Blue made into the left ventricular wall labelled sympathetic neurons that were located along the medial border of both the left and right stellate ganglia. Cardiac projecting sympathetic postganglionic neurons could be grouped into one of four neurochemical populations, characterised by their content of calbindin and/or neuropeptide Y (NPY). The subpopulations of neurons contained immunoreactivity to both calbindin and NPY, immunoreactivity to calbindin only, immunoreactivity to NPY only and no immunoreactivity to calbindin or NPY. Sympathetic postganglionic neurons were also labelled in vitro with rhodamine dextran applied to the cut end of a cardiac nerve. The same neurochemical subpopulations of sympathetic neurons were identified by using this technique but in different proportions to those labelled from the left ventricle. Preganglionic terminals that were immunoreactive for another calcium-binding protein, calretinin, preferentially surrounded retrogradely labelled neurons that were immunoreactive for both calbindin and NPY. The separate sympathetic pathways projecting to the rat heart may control different cardiac functions.

  16. Temporary Blindness after Inferior Alveolar Nerve Block.

    Science.gov (United States)

    Barodiya, Animesh; Thukral, Rishi; Agrawal, Shaila Mahendra; Rai, Anshul; Singh, Siddharth

    2017-03-01

    Inferior Alveolar Nerve Block (IANB) anaesthesia is one of the common procedures in dental clinic. This procedure is safe, but complications may still occur. Ocular complications such as diplopia, loss of vision, or ophthalmoplegia are extremely rare. This case report explains an event where due to individual anatomic variation of the sympathetic vasoconstrictor nerve and maxillary and middle meningeal arteries, intravascular administration of anaesthetic agent caused unusual ocular signs and symptoms such as temporary blindness.

  17. Imaging of Pericardiophrenic Bundles Using Multislice Spiral Computed Tomography for Phrenic Nerve Anatomy.

    Science.gov (United States)

    Wang, Yan-Jing; Liu, Lin; Zhang, Meng-Chao; Sun, Huan; Zeng, Hong; Yang, Ping

    2016-08-01

    Phrenic nerve injury and diaphragmatic stimulation are common complications following arrhythmia ablation and pacing therapies. Preoperative comprehension of phrenic nerve anatomy via non-invasive CT imaging may help to minimize the electrophysiological procedure-related complications. Coronary CT angiography data of 121 consecutive patients were collected. Imaging of left and right pericardiophrenic bundles was performed with volume rendering and multi-planar reformation techniques. The shortest spatial distances between phrenic nerves and key electrophysiology-related structures were determined. The frequencies of the shortest distances ≤5 mm, >5 mm and direct contact between phrenic nerves and adjacent structures were calculated. Left and right pericardiophrenic bundles were identified in 86.8% and 51.2% of the patients, respectively. The right phrenic nerve was phrenic nerve, phrenic nerve was phrenic nerve had a distance phrenic nerve showed a distance phrenic nerve anatomy, which might facilitate avoidance of the phrenic nerve-related complications in interventional electrophysiology. © 2016 Wiley Periodicals, Inc.

  18. Muscle afferent receptors engaged in augmented sympathetic responsiveness in peripheral artery disease

    Directory of Open Access Journals (Sweden)

    Jianhua eLi

    2012-07-01

    Full Text Available The exercise pressor reflex (EPR is a neural control mechanism responsible for the cardiovascular responses to exercise. As exercise is initiated, thin fiber muscle afferent nerves are activated by mechanical and metabolic stimuli arising in the contracting muscles. This leads to reflex increases in arterial blood pressure and heart rate primarily through activation of sympathetic nerve activity (SNA. Studies of humans and animals have indicated that the EPR is exaggerated in a number of cardiovascular diseases. For the last several years, studies have specifically employed a rodent model to examine the mechanisms at receptor and cellular levels by which responses of SNA and blood pressure to static exercise are heightened in peripheral artery disease (PAD, one of the most common cardiovascular disorders. A rat model of this disease has well been established. Specifically, femoral artery occlusion is used to study intermittent claudication that is observed in human PAD. The receptors on thin fiber muscle afferents that are engaged in this disease include transient receptor potential vanilloid type 1 (TRPV1, purinergic P2X and acid sensing ion channel (ASIC. The role played by nerve growth factor (NGF in regulating those sensory receptors in the processing of amplified EPR was also investigated. The purpose of this review is to focus on a theme namely that PAD accentuates autonomic reflex responses to exercise and further address regulatory mechanisms leading to abnormal sympathetic responsiveness. This review will present some of recent results in regard with several receptors in muscle sensory neurons in contribution to augmented autonomic reflex responses in PAD. Review of the findings from recent studies would lead to a better understanding in integrated processing of sympathetic nervous system in PAD.

  19. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica

    International Nuclear Information System (INIS)

    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang

    2015-01-01

    Highlights: •In the present study, we first elected ROIs corresponding to the proximal, medial, and distal levels of the lumbar foraminal zone. •The ROC analysis for FA values of distal nerves indicated a high level of reliability in the diagnosis of sciatica. •The declining trend of FA values from proximal to distal along the nerve tract may correlate with the disparity of axonal regeneration at different levels. •DTI is able to quantitatively evaluate compressed nerve roots and has a higher sensitivity and specificity for diagnosing sciatica than conventional MR imaging. •DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and probable localization of nerve compression. -- Abstract: Objective: To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Materials and methods: Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5–S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3–S1 nerve roots. ROC analysis was performed for FA values. Results: The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. Conclusions: DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica

  20. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang, E-mail: njmu_wangdehang@126.com

    2015-04-15

    Highlights: •In the present study, we first elected ROIs corresponding to the proximal, medial, and distal levels of the lumbar foraminal zone. •The ROC analysis for FA values of distal nerves indicated a high level of reliability in the diagnosis of sciatica. •The declining trend of FA values from proximal to distal along the nerve tract may correlate with the disparity of axonal regeneration at different levels. •DTI is able to quantitatively evaluate compressed nerve roots and has a higher sensitivity and specificity for diagnosing sciatica than conventional MR imaging. •DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and probable localization of nerve compression. -- Abstract: Objective: To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Materials and methods: Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5–S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3–S1 nerve roots. ROC analysis was performed for FA values. Results: The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. Conclusions: DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica.

  1. Quantitation of cardiac sympathetic innervation in rabbits using 11C-hydroxyephedrine PET: relation to 123I-MIBG uptake

    International Nuclear Information System (INIS)

    Nomura, Yusuke; Kajinami, Kouji; Matsunari, Ichiro; Takamatsu, Hiroyuki; Murakami, Yoshihiro; Matsuya, Takahiro; Chen, Wei-Ping; Taki, Junichi; Nakajima, Kenichi; Nekolla, Stephan G.

    2006-01-01

    Although 11 C-hydroxyephedrine ( 11 C-HED) PET is used to map cardiac sympathetic innervation, no studies have shown the feasibility of quantitation of 11 C-HED PET in small- to medium-sized animals. Furthermore, its relation to 123 I-MIBG uptake, the most widely used sympathetic nervous tracer, is unknown. The aims of this study were to establish in vivo sympathetic nerve imaging in rabbits using 11 C-HED PET, and to compare the retention of 11 C-HED with that of 123 I-MIBG. Twelve rabbits were assigned to three groups; control (n=4), chemical denervation by 6-hydroxydopamine (6-OHDA) (n=4) and reserpine treated to inhibit vesicular uptake (n=4). After simultaneous injection of 11 C-HED and 123 I-MIBG, all animals underwent dynamic 11 C-HED PET for 40 min with arterial blood sampling. The 11 C-HED retention fraction and normalised 11 C-HED activity measured by tissue sampling were compared with those measured by PET. Both the 11 C-HED retention fraction and the normalised 11 C-HED activity measured by PET correlated closely with those measured by tissue sampling (R=0.96027, p 11 C-HED and 123 I-MIBG. Reserpine pretreatment reduced 11 C-HED retention by 50%, but did not reduce 123 I-MIBG retention at 40 min after injection. Non-invasive quantitation of cardiac sympathetic innervation using 11 C-HED PET is feasible and gives reliable estimates of cardiac sympathetic innervation in rabbits. Additionally, although both 11 C-HED and 123 I-MIBG are specific for sympathetic neurons, 11 C-HED may be more specific for intravesicular uptake than 123 I-MIBG in some situations, such as that seen in reserpine pretreatment. (orig.)

  2. MR imaging of the cranial nerves and the intracranial vessels using 3D-SPGR

    International Nuclear Information System (INIS)

    Hosoya, Takaaki; Sato, Nami; Yamaguchi, Koichi; Sugai, Yukio; Ogushi, Masatoshi; Kubota, Hisashi

    1992-01-01

    MR angiography (MRA) has developed rapidly, but it is still insufficient to demonstrate the detail of the intracranial vascular anatomy. We found that original images of MRA render more information than MRA images about not only intracranial vessels but also cranial nerves. We have tried to demonstrate cranial nerves and intracranial vessels on 26 patients and evaluated using real time reformation of original images of MRA. MR images were obtained by SPGR (3DFT) after injection of Gd-DTPA. The optic nerve, the oculomotor nerve, the trigeminal nerve, the facial nerve and the vestibulocochlear nerve were visualized clearly on almost patients and detectabilities of these nerves were 100%, 98%, 100%, 94% and 100%, respectively. The abducent nerve was also detectable in 76%. The trochlear nerve, which could not be observed by any modality, was detected at prepontine cistern in 10%. Arteries around brain stem such as the superior cerebellar artery (SCA), the anterior inferior cerebellar artery (AICA), the posterior inferior cerebellar artery (PICA) and the posterior communicating artery (PcomA) were clearly visible, and branching of these arteries and anatomical detail were completely coincide with angiogram on 12 patients. The basal vein of Rosenthal and the petrosal vein were confirmed in 100% and their anastomose were demonstrated obviously. We concluded that this method was extremely useful to observe cranial nerves and intracranial small vessels. (author)

  3. Imaging the cranial nerves: part II: primary and secondary neoplastic conditions and neurovascular conflicts

    International Nuclear Information System (INIS)

    Borges, Alexandra; Casselman, Jan

    2007-01-01

    There have been unprecedented improvements in cross-sectional imaging in the last decades. The emergence of volumetric CT, higher field MR scanners and higher resolution MR sequences is largely responsible for the increasing diagnostic yield of imaging in patients presenting with cranial nerve deficits. The introduction of parallel MR imaging in combination with small surface coils allows the depiction of submillimetric nerves and nerve branches, and volumetric CT and MR imaging is able to provide high quality multiplanar and curved reconstructions that can follow the often complex course of cranial nerves. Seeking the cause of a cranial nerve deficit is a common indication for imaging, and it is not uncommon that radiologists are the first specialists to see a patient with a cranial neuropathy. To increase the diagnostic yield of imaging, high-resolution studies with smaller fields of view are required. To keep imaging studies within a reasonable time frame, it is mandatory to tailor the study according to neuro-topographic testing. This review article focuses on the contribution of current imaging techniques in the depiction of primary and secondary neoplastic conditions affecting the cranial nerves as well as on neurovascular conflicts, an increasingly recognized cause of cranial neuralgias. (orig.)

  4. Imaging the cranial nerves: part II: primary and secondary neoplastic conditions and neurovascular conflicts

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Instituto Portugues de Oncologia Francisco Gentil- Centro de Lisboa, Radiology Department, Lisboa Codex (Portugal); Casselman, Jan [A. Z. St Jan Brugge and A. Z. St Augustinus Antwerpen Hospitals, Department of Radiology, Antwerp (Belgium)

    2007-09-15

    There have been unprecedented improvements in cross-sectional imaging in the last decades. The emergence of volumetric CT, higher field MR scanners and higher resolution MR sequences is largely responsible for the increasing diagnostic yield of imaging in patients presenting with cranial nerve deficits. The introduction of parallel MR imaging in combination with small surface coils allows the depiction of submillimetric nerves and nerve branches, and volumetric CT and MR imaging is able to provide high quality multiplanar and curved reconstructions that can follow the often complex course of cranial nerves. Seeking the cause of a cranial nerve deficit is a common indication for imaging, and it is not uncommon that radiologists are the first specialists to see a patient with a cranial neuropathy. To increase the diagnostic yield of imaging, high-resolution studies with smaller fields of view are required. To keep imaging studies within a reasonable time frame, it is mandatory to tailor the study according to neuro-topographic testing. This review article focuses on the contribution of current imaging techniques in the depiction of primary and secondary neoplastic conditions affecting the cranial nerves as well as on neurovascular conflicts, an increasingly recognized cause of cranial neuralgias. (orig.)

  5. MR-guided Periarterial Ethanol Injection for Renal Sympathetic Denervation: A Feasibility Study in Pigs

    International Nuclear Information System (INIS)

    Streitparth, F.; Walter, A.; Stolzenburg, N.; Heckmann, L.; Breinl, J.; Rinnenthal, J. L.; Beck, A.; De Bucourt, M.; Schnorr, J.; Bernhardt, U.; Gebauer, B.; Hamm, B.; Günther, R. W.

    2013-01-01

    Purpose. To evaluate the feasibility and efficacy of image-guided periarterial ethanol injection as an alternative to transluminal radiofrequency ablation. Methods. Unilateral renal periarterial ethanol injection was performed under general anesthesia in 6 pigs with the contralateral kidney serving as control. All interventions were performed in an open 1.0 T MRI system under real-time multiplanar guidance. The injected volume was 5 ml (95 % ethanol labelled marked MR contrast medium) in 2 pigs and 10 ml in 4 pigs. Four weeks after treatment, the pigs underwent MRI including MRA and were killed. Norepinephrine (NE) concentration in the renal parenchyma served as a surrogate parameter to analyze the efficacy of sympathetic denervation. In addition, the renal artery and sympathetic nerves were examined histologically to identify evidence of vascular and neural injury. Results. In pigs treated with 10 ml ethanol, treatment resulted in neural degeneration. We found a significant reduction of NE concentration in the kidney parenchyma of 53 % (p < 0.02) compared with the untreated contralateral kidney. In pigs treated with 5 ml ethanol, no significant changes in histology or NE were observed. There was no evidence of renal arterial stenosis in MRI, macroscopy or histology in any pig. Conclusion. MR-guided periarterial ethanol injection was feasible and efficient for renal sympathetic denervation in a swine model. This technique may be a promising alternative to the catheter-based approach in the treatment of resistant arterial hypertension.

  6. MR-guided Periarterial Ethanol Injection for Renal Sympathetic Denervation: A Feasibility Study in Pigs

    Energy Technology Data Exchange (ETDEWEB)

    Streitparth, F., E-mail: florian.streitparth@charite.de; Walter, A.; Stolzenburg, N.; Heckmann, L.; Breinl, J. [Charite, Humboldt University, Department of Radiology (Germany); Rinnenthal, J. L. [Charite, Humboldt University, Department of Neuropathology (Germany); Beck, A.; De Bucourt, M.; Schnorr, J. [Charite, Humboldt University, Department of Radiology (Germany); Bernhardt, U. [InnoRa GmbH (Germany); Gebauer, B.; Hamm, B.; Guenther, R. W. [Charite, Humboldt University, Department of Radiology (Germany)

    2013-06-15

    Purpose. To evaluate the feasibility and efficacy of image-guided periarterial ethanol injection as an alternative to transluminal radiofrequency ablation. Methods. Unilateral renal periarterial ethanol injection was performed under general anesthesia in 6 pigs with the contralateral kidney serving as control. All interventions were performed in an open 1.0 T MRI system under real-time multiplanar guidance. The injected volume was 5 ml (95 % ethanol labelled marked MR contrast medium) in 2 pigs and 10 ml in 4 pigs. Four weeks after treatment, the pigs underwent MRI including MRA and were killed. Norepinephrine (NE) concentration in the renal parenchyma served as a surrogate parameter to analyze the efficacy of sympathetic denervation. In addition, the renal artery and sympathetic nerves were examined histologically to identify evidence of vascular and neural injury. Results. In pigs treated with 10 ml ethanol, treatment resulted in neural degeneration. We found a significant reduction of NE concentration in the kidney parenchyma of 53 % (p < 0.02) compared with the untreated contralateral kidney. In pigs treated with 5 ml ethanol, no significant changes in histology or NE were observed. There was no evidence of renal arterial stenosis in MRI, macroscopy or histology in any pig. Conclusion. MR-guided periarterial ethanol injection was feasible and efficient for renal sympathetic denervation in a swine model. This technique may be a promising alternative to the catheter-based approach in the treatment of resistant arterial hypertension.

  7. The cisternal segment of the abducens nerve in man: three-dimensional MR imaging

    International Nuclear Information System (INIS)

    Alkan, Alpay; Sigirci, Ahmet; Ozveren, M. Faik; Kutlu, Ramazan; Altinok, Tayfun; Onal, Cagatay; Sarac, Kaya

    2004-01-01

    Purpose: The goal of this study was to identify the abducens nerve in its cisternal segment by using three-dimensional turbo spin echo T2-weighted image (3DT2-TSE). The abducens nerve may arise from the medullopontine sulcus by one singular or two separated rootlets. Material and methods: We studied 285 patients (150 males, 135 females, age range: 9-72 years, mean age: 33.3±14.4) referred to MR imaging of the inner ear, internal auditory canal and brainstem. All 3D T2-TSE studies were performed with a 1.5 T MR system. Imaging parameters used for 3DT2-TSE sequence were TR:4000, TE:150, and 0.70 mm slice thickness. A field of view of 160 mm and 256x256 matrix were used. The double rootlets of the abducens nerve and contralateral abducens nerves and their relationships with anatomical structures were searched in the subarachnoid space. Results: We identified 540 of 570 abducens nerves (94.7%) in its complete cisternal course with certainty. Seventy-two cases (25.2%) in the present study had double rootlets of the abducens nerve. In 59 of these cases (34 on the right side and 25 on the left) presented with unilateral double rootlets of the abducens. Thirteen cases presented with bilateral double rootlets of the abducens (4.5%). Conclusion: An abducens nerve arising by two separate rootlets is not a rare variation. The detection of this anatomical variation by preoperative MR imaging is important to avoid partial damage of the nerve during surgical procedures. The 3DT2-TSE as a noninvasive technique makes it possible to obtain extremely high-quality images of microstructures as cranial nerves and surrounding vessels in the cerebellopontine cistern. Therefore, preoperative MR imaging should be performed to detect anatomical variations of abducens nerve and to reduce the chance of operative injuries

  8. Egr3 dependent sympathetic target tissue innervation in the absence of neuron death.

    Directory of Open Access Journals (Sweden)

    Lin Li

    Full Text Available Nerve Growth Factor (NGF is a target tissue derived neurotrophin required for normal sympathetic neuron survival and target tissue innervation. NGF signaling regulates gene expression in sympathetic neurons, which in turn mediates critical aspects of neuron survival, axon extension and terminal axon branching during sympathetic nervous system (SNS development. Egr3 is a transcription factor regulated by NGF signaling in sympathetic neurons that is essential for normal SNS development. Germline Egr3-deficient mice have physiologic dysautonomia characterized by apoptotic sympathetic neuron death and abnormal innervation to many target tissues. The extent to which sympathetic innervation abnormalities in the absence of Egr3 is caused by altered innervation or by neuron death during development is unknown. Using Bax-deficient mice to abrogate apoptotic sympathetic neuron death in vivo, we show that Egr3 has an essential role in target tissue innervation in the absence of neuron death. Sympathetic target tissue innervation is abnormal in many target tissues in the absence of neuron death, and like NGF, Egr3 also appears to effect target tissue innervation heterogeneously. In some tissues, such as heart, spleen, bowel, kidney, pineal gland and the eye, Egr3 is essential for normal innervation, whereas in other tissues such as lung, stomach, pancreas and liver, Egr3 appears to have little role in innervation. Moreover, in salivary glands and heart, two tissues where Egr3 has an essential role in sympathetic innervation, NGF and NT-3 are expressed normally in the absence of Egr3 indicating that abnormal target tissue innervation is not due to deregulation of these neurotrophins in target tissues. Taken together, these results clearly demonstrate a role for Egr3 in mediating sympathetic target tissue innervation that is independent of neuron survival or neurotrophin deregulation.

  9. Facial Nerve Paralysis due to a Pleomorphic Adenoma with the Imaging Characteristics of a Facial Nerve Schwannoma.

    Science.gov (United States)

    Nader, Marc-Elie; Bell, Diana; Sturgis, Erich M; Ginsberg, Lawrence E; Gidley, Paul W

    2014-08-01

    Background Facial nerve paralysis in a patient with a salivary gland mass usually denotes malignancy. However, facial paralysis can also be caused by benign salivary gland tumors. Methods We present a case of facial nerve paralysis due to a benign salivary gland tumor that had the imaging characteristics of an intraparotid facial nerve schwannoma. Results The patient presented to our clinic 4 years after the onset of facial nerve paralysis initially diagnosed as Bell palsy. Computed tomography demonstrated filling and erosion of the stylomastoid foramen with a mass on the facial nerve. Postoperative histopathology showed the presence of a pleomorphic adenoma. Facial paralysis was thought to be caused by extrinsic nerve compression. Conclusions This case illustrates the difficulty of accurate preoperative diagnosis of a parotid gland mass and reinforces the concept that facial nerve paralysis in the context of salivary gland tumors may not always indicate malignancy.

  10. 4.7-T diffusion tensor imaging of acute traumatic peripheral nerve injury.

    Science.gov (United States)

    Boyer, Richard B; Kelm, Nathaniel D; Riley, D Colton; Sexton, Kevin W; Pollins, Alonda C; Shack, R Bruce; Dortch, Richard D; Nanney, Lillian B; Does, Mark D; Thayer, Wesley P

    2015-09-01

    Diagnosis and management of peripheral nerve injury is complicated by the inability to assess microstructural features of injured nerve fibers via clinical examination and electrophysiology. Diffusion tensor imaging (DTI) has been shown to accurately detect nerve injury and regeneration in crush models of peripheral nerve injury, but no prior studies have been conducted on nerve transection, a surgical emergency that can lead to permanent weakness or paralysis. Acute sciatic nerve injuries were performed microsurgically to produce multiple grades of nerve transection in rats that were harvested 1 hour after surgery. High-resolution diffusion tensor images from ex vivo sciatic nerves were obtained using diffusion-weighted spin-echo acquisitions at 4.7 T. Fractional anisotropy was significantly reduced at the injury sites of transected rats compared with sham rats. Additionally, minor eigenvalues and radial diffusivity were profoundly elevated at all injury sites and were negatively correlated to the degree of injury. Diffusion tensor tractography showed discontinuities at all injury sites and significantly reduced continuous tract counts. These findings demonstrate that high-resolution DTI is a promising tool for acute diagnosis and grading of traumatic peripheral nerve injuries.

  11. Imaging of Cranial Nerves III, IV, VI in Congenital Cranial Dysinnervation Disorders.

    Science.gov (United States)

    Kim, Jae Hyoung; Hwang, Jeong Min

    2017-06-01

    Congenital cranial dysinnervation disorders are a group of diseases caused by abnormal development of cranial nerve nuclei or their axonal connections, resulting in aberrant innervation of the ocular and facial musculature. Its diagnosis could be facilitated by the development of high resolution thin-section magnetic resonance imaging. The purpose of this review is to describe the method to visualize cranial nerves III, IV, and VI and to present the imaging findings of congenital cranial dysinnervation disorders including congenital oculomotor nerve palsy, congenital trochlear nerve palsy, Duane retraction syndrome, Möbius syndrome, congenital fibrosis of the extraocular muscles, synergistic divergence, and synergistic convergence. © 2017 The Korean Ophthalmological Society.

  12. Estimation of regional myocardial sympathetic neuronal function with I-123 metaiodobenzylguanidine (MIBG) myocardial images in patients with cardiomyopathy

    International Nuclear Information System (INIS)

    Tanaka, Takeshi; Aizawa, Tadanori; Kato, Kazuzo; Nakano, Hajime; Igarashi, Masaki; Ueno, Takashi; Hirosawa, Koshichiro; Kusakabe, Kiyoko.

    1989-01-01

    Myocardial SPECT images with I-123 metaiodobenzylguanidine (MIBG) were obtained in 10 patients with cardiomyopathy under stable state. For myocardial imaging, MIBG and Tl-201 (Tl) were simultaneously injected and collected. The ratio of MIBG to Tl (M/T ratio) in ROI was obtained with 50% cut off levels in order to eliminate background activity. The patients were divided into three major groups: (l) those who had the M/T ratio ranging from 0.8 to l.20 at rest and had marked defects in the infero-lateral region on delayed MIBG images, where pathophysiologically accelerated regional sympathetic neuronal function was suspected (n=5), (II) those who had increased M/T ratios (l.6 and l.7) in the basal septal wall (n=3), and (III) those who had decreased M/T ratios (0.7 and 0.75) in the apical septal wall, where depletion of myocardial norepinephrine was suspected (n=2). These findings indicate the potential of myocardial MIBG images to evaluate myocardial distribution of norepinephrine, i.e. myocardial sympathetic neuronal function. Certain shortcomings, such as an increased background due to dual isotopes and an increased pulmonary uptake of MIBG, require further study on quantitative methods. (Namekawa, K)

  13. Magnetic resonance imaging in optic nerve lesions with multiple sclerosis

    International Nuclear Information System (INIS)

    Kojima, Shigeyuki; Hirayama, Keizo; Kakisu, Yonetsugu; Adachi, Emiko

    1990-01-01

    Magnetic resonance imaging (MRI) of the optic nerve was performed in 10 patients with multiple sclerosis (MS) using short inversion time inversion recovery (STIR) pulse sequences, and the results were compared with the visual evoked potentials (VEP). The 10 patients had optic neuritis in the chronic or remitting phase together with additional symptoms or signs allowing a diagnosis of clinically definite or probable MS. Sixteen optic nerves were clinically affected and 4 were unaffected. MRI was performed using a 0.5 tesla supeconducting unit, and multiple continuous 5 mm coronal and axial STIR images were obtained. A lesion was judged to be present if a focal or diffuse area of increased signal intensity was detectd in the optic nerve. In VEP, a delay in peak latency or no P 100 component was judged to be abnormal. With regard to the clinically affected optic nerves, MRI revealed a region of increased signal intensity in 14/16 (88%) and the VEP was abnormal in 16/16 (100%). In the clinically unaffected optic nerves, MRI revealed an increased signal intensity in 2/4 (50%). One of these nerves had an abnormal VEP and the other had a VEP latency at the upper limit of normal. The VEP was abnormal in 1/4 (25%). In the clinically affected optic nerves, the degree of loss of visual acuity was not associated with the longitudinal extent of the lesions shown by MRI. The mean length was 17.5 mm in optic nerves with a slight disturbance of visual acuity and 15.0 mm in nerves with severe visual loss. MRI using STIR pulse sequences was found to be almost as sensitive as VEP in detecting both clinically affected and unaffected optic nerve lesions in patients with MS, and was useful in visualizing the location or size of the lesions. (author)

  14. Trigeminal nerve involvement in T-cell acute lymphoblastic leukemia: value of MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Karadag, Demet; Karaguelle, Ayse Tuba; Erden, Ilhan; Erden, Ayse E-mail: erden@ada.net.tr

    2002-10-01

    A 30-year-old male with T-cell acute lymphoblastic leukemia presented with facial numbness. Neurological examination revealed paresthesia of the left trigeminal nerve. Cerebrospinal fluid (CSF) cytology showed no atypical cells. Gadolinium-enhanced magnetic resonance (MR) imaging demonstrated enlargement and enhancement of intracranial portions of the left trigeminal nerve. The abnormal MR imaging findings almost completely resolved after the chemotherapy. Gadolinium-enhanced MR imaging is not only a useful procedure for the early diagnosis of cranial nerve invasion by leukemia but it might be helpful to follow the changes after the treatment.

  15. Functional role of peripheral opioid receptors in the regulation of cardiac spinal afferent nerve activity during myocardial ischemia

    Science.gov (United States)

    Longhurst, John C.

    2013-01-01

    Thinly myelinated Aδ-fiber and unmyelinated C-fiber cardiac sympathetic (spinal) sensory nerve fibers are activated during myocardial ischemia to transmit the sensation of angina pectoris. Although recent observations showed that myocardial ischemia increases the concentrations of opioid peptides and that the stimulation of peripheral opioid receptors inhibits chemically induced visceral and somatic nociception, the role of opioids in cardiac spinal afferent signaling during myocardial ischemia has not been studied. The present study tested the hypothesis that peripheral opioid receptors modulate cardiac spinal afferent nerve activity during myocardial ischemia by suppressing the responses of cardiac afferent nerve to ischemic mediators like bradykinin and extracellular ATP. The nerve activity of single unit cardiac afferents was recorded from the left sympathetic chain (T2–T5) in anesthetized cats. Forty-three ischemically sensitive afferent nerves (conduction velocity: 0.32–3.90 m/s) with receptive fields in the left and right ventricles were identified. The responses of these afferent nerves to repeat ischemia or ischemic mediators were further studied in the following protocols. First, epicardial administration of naloxone (8 μmol), a nonselective opioid receptor antagonist, enhanced the responses of eight cardiac afferent nerves to recurrent myocardial ischemia by 62%, whereas epicardial application of vehicle (PBS) did not alter the responses of seven other cardiac afferent nerves to ischemia. Second, naloxone applied to the epicardial surface facilitated the responses of seven cardiac afferent nerves to epicardial ATP by 76%. Third, administration of naloxone enhanced the responses of seven other afferent nerves to bradykinin by 85%. In contrast, in the absence of naloxone, cardiac afferent nerves consistently responded to repeated application of ATP (n = 7) or bradykinin (n = 7). These data suggest that peripheral opioid peptides suppress the

  16. Unusually large quiescent ancient schwannoma of hypoglossal nerve

    Directory of Open Access Journals (Sweden)

    Sangeeta P Wanjari

    2013-01-01

    Full Text Available Ancient schwannoma is considered as a variant of schwannoma, comprising about 10% of all schwanommas. Schwannoma is a benign neoplasm derived from the nerve sheath of peripheral motor, sensory and sympathetic nerves and from the cranial nerve pairs. It usually presents as a solitary soft-tissue lesion which is slow growing, encapsulated and is often associated with nerve attached peripherally. Diagnosis is often confirmed with the microscopic examination. The long standing schwannoma attributes to degenerative changes and is termed "ancient" schwannoma. Present case is of a 68-year-old female patient who reported with an asymptomatic large swelling below mandible on the left side since last 23 years. The lesion was surgically excised under general anesthesia.

  17. Vagal nerve stimulation therapy: what is being stimulated?

    Science.gov (United States)

    Kember, Guy; Ardell, Jeffrey L; Armour, John A; Zamir, Mair

    2014-01-01

    Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

  18. Vagal nerve stimulation therapy: what is being stimulated?

    Directory of Open Access Journals (Sweden)

    Guy Kember

    Full Text Available Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

  19. Positron emission tomographic imaging of cardiac sympathetic innervation and function

    International Nuclear Information System (INIS)

    Goldstein, D.S.; Chang, P.C.; Eisenhofer, G.; Miletich, R.; Finn, R.; Bacher, J.; Kirk, K.L.; Bacharach, S.; Kopin, I.J.

    1990-01-01

    Sites of uptake, storage, and metabolism of [ 18 F]fluorodopamine and excretion of [ 18 F]fluorodopamine and its metabolites were visualized using positron emission tomographic (PET) scanning after intravenous injection of the tracer into anesthetized dogs. Radioactivity was concentrated in the renal pelvis, heart, liver, spleen, salivary glands, and gall bladder. Uptake of 18F by the heart resulted in striking delineation of the left ventricular myocardium. Pretreatment with desipramine markedly decreased cardiac positron emission, consistent with dependence of the heart on neuronal uptake (uptake-1) for removal of circulating catecholamines. In reserpinized animals, cardiac positron emission was absent within 30 minutes after injection of [ 18 F]-6-fluorodopamine, demonstrating that the emission in untreated animals was from radioactive labeling of the sympathetic storage vesicles. Decreased positron emission from denervated salivary glands confirmed that the tracer was concentrated in sympathetic neurons. Radioactivity in the gall bladder and urinary system depicted the hepatic and renal excretion of the tracer and its metabolites. Administration of tyramine or nitroprusside increased and ganglionic blockade with trimethaphan decreased the rate of loss of myocardial radioactivity. The results show that PET scanning after administration of [ 18 F]fluorodopamine can be used to visualize sites of sympathetic innervation, follow the metabolism and renal and hepatic excretion of catecholamines, and examine cardiac sympathetic function

  20. The renal nerves in chronic heart failure: efferent and afferent mechanisms

    Science.gov (United States)

    Schiller, Alicia M.; Pellegrino, Peter R.; Zucker, Irving H.

    2015-01-01

    The function of the renal nerves has been an area of scientific and medical interest for many years. The recent advent of a minimally invasive catheter-based method of renal denervation has renewed excitement in understanding the afferent and efferent actions of the renal nerves in multiple diseases. While hypertension has been the focus of much this work, less attention has been given to the role of the renal nerves in the development of chronic heart failure (CHF). Recent studies from our laboratory and those of others implicate an essential role for the renal nerves in the development and progression of CHF. Using a rabbit tachycardia model of CHF and surgical unilateral renal denervation, we provide evidence for both renal efferent and afferent mechanisms in the pathogenesis of CHF. Renal denervation prevented the decrease in renal blood flow observed in CHF while also preventing increases in Angiotensin-II receptor protein in the microvasculature of the renal cortex. Renal denervation in CHF also reduced physiological markers of autonomic dysfunction including an improvement in arterial baroreflex function, heart rate variability, and decreased resting cardiac sympathetic tone. Taken together, the renal sympathetic nerves are necessary in the pathogenesis of CHF via both efferent and afferent mechanisms. Additional investigation is warranted to fully understand the role of these nerves and their role as a therapeutic target in CHF. PMID:26300788

  1. The Renal Nerves in Chronic Heart Failure: Afferent and Efferent Mechanisms

    Directory of Open Access Journals (Sweden)

    Alicia Marie Schiller

    2015-08-01

    Full Text Available The function of the renal nerves has been an area of scientific and medical interest for many years. The recent advent of a minimally invasive catheter-based method of renal denervation has renewed excitement in understanding the afferent and efferent actions of the renal nerves in multiple diseases. While hypertension has been the focus of much this work, less attention has been given to the role of the renal nerves in the development of chronic heart failure (CHF. Recent studies from our laboratory and those of others implicate an essential role for the renal nerves in the development and progression of CHF. Using a rabbit tachycardia model of CHF and surgical unilateral renal denervation, we provide evidence for both renal efferent and afferent mechanisms in the pathogenesis of CHF. Renal denervation prevented the decrease in renal blood flow observed in CHF while also preventing increases in Angiotensin-II receptor protein in the microvasculature of the renal cortex. Renal denervation in CHF also reduced physiological markers of autonomic dysfunction including an improvement in arterial baroreflex function, heart rate variability, and decreased resting cardiac sympathetic tone. Taken together, the renal sympathetic nerves are necessary in the pathogenesis of CHF via both efferent and afferent

  2. Detailed comparative anatomy of the extrinsic cardiac nerve plexus and postnatal reorganization of the cardiac position and innervation in the great apes: orangutans, gorillas, and chimpanzees.

    Science.gov (United States)

    Kawashima, Tomokazu; Sato, Fumi

    2012-03-01

    To speculate how the extrinsic cardiac nerve plexus (ECNP) evolves phyletically and ontogenetically within the primate lineage, we conducted a comparative anatomical study of the ECNP, including an imaging examination in the great apes using 20 sides from 11 bodies from three species and a range of postnatal stages from newborns to mature adults. Although the position of the middle cervical ganglion (MG) in the great apes tended to be relatively lower than that in humans, the morphology of the ECNP in adult great apes was almost consistent with that in adult humans but essentially different from that in the lesser apes or gibbons. Therefore, the well-argued anatomical question of when did the MG acquire communicating branches with the spinal cervical nerves and appear constantly in all sympathetic cardiac nerves during primate evolution is clearly considered to be after the great apes and gibbons split. Moreover, a horizontal four-chambered heart and a lifted cardiac apex with a relatively large volume in newborn great apes rapidly changed its position downward, as seen in humans during postnatal growth and was associated with a reduction in the hepatic volume by imaging diagnosis and gross anatomy. In addition, our observation using a range of postnatal stages exhibits that two sympathetic ganglia, the middle cervical and cervicothoracic ganglia, differed between the early and later postnatal stages. Copyright © 2011 Wiley Periodicals, Inc.

  3. An implantable nerve cooler for the exercising dog.

    Science.gov (United States)

    Borgdorff, P; Versteeg, P G

    1984-01-01

    An implantable nerve cooler has been constructed to block cervical vago-sympathetic activity in the exercising dog reversibly. An insulated gilt brass container implanted around the nerve is perfused with cooled alcohol via silicone tubes. The flow of alcohol is controlled by an electromagnetic valve to keep nerve temperature at the required value. Nerve temperature is measured by a thermistor attached to the housing and in contact with the nerve. It is shown that, during cooling, temperature at this location differs less than 2 degrees C from nerve core temperature. Measurement of changes in heart rate revealed that complete vagal block in the conscious animal is obtained at a nerve temperature of 2 degrees C and can be achieved within 50 s. During steady-state cooling in the exercising animal nerve temperature varied less than 0.5 degree C. When the coolers after 2 weeks of implantation were removed they showed no oxydation and could be used again.

  4. Thermography imaging during static and controlled thermoregulation in complex regional pain syndrome type 1: diagnostic value and involvement of the central sympathetic system

    Directory of Open Access Journals (Sweden)

    Westra Mirjam

    2006-05-01

    Full Text Available Abstract Background Complex Regional Pain Syndrome type 1 (CRPS1 is a clinical diagnosis based on criteria describing symptoms of the disease. The main aim of the present study was to compare the sensitivity and specificity of calculation methods used to assess thermographic images (infrared imaging obtained during temperature provocation. The secondary objective was to obtain information about the involvement of the sympathetic system in CRPS1. Methods We studied 12 patients in whom CRPS1 was diagnosed according to the criteria of Bruehl. High and low whole body cooling and warming induced and reduced sympathetic vasoconstrictor activity. The degree of vasoconstrictor activity in both hands was monitored using a videothermograph. The sensitivity and specificity of the calculation methods used to assess the thermographic images were calculated. Results The temperature difference between the hands in the CRPS patients increases significantly when the sympathetic system is provoked. At both the maximum and minimum vasoconstriction no significant differences were found in fingertip temperatures between both hands. Conclusion The majority of CRPS1 patients do not show maximal obtainable temperature differences between the involved and contralateral extremity at room temperature (static measurement. During cold and warm temperature challenges this temperature difference increases significantly. As a result a higher sensitivity and specificity could be achieved in the diagnosis of CRPS1. These findings suggest that the sympathetic efferent system is involved in CRPS1.

  5. The gross anatomy of the renal sympathetic nerves revisited.

    Science.gov (United States)

    Mompeo, Blanca; Maranillo, Eva; Garcia-Touchard, Arturo; Larkin, Theresa; Sanudo, Jose

    2016-07-01

    Catheter-based renal denervation techniques focus on reducing blood pressure in resistant hypertension. This procedure requires exact knowledge of the anatomical interrelation between the renal arteries and the targeted renal nervous plexus. The aim of this work was to build on classical anatomical studies and describe the gross anatomy and anatomical relationships of the renal arteries and nerve supply to the kidneys in a sample of human cadavers. Twelve human cadavers (six males and six females), age range 73 to 94 years, were dissected. The nervous fibers and renal arteries were dissected using a surgical microscope. The renal plexus along the hilar renal artery comprised a fiber-ganglionic ring surrounding the proximal third of the renal artery, a neural network along the middle and distal thirds, and smaller accessory ganglia along the course of the nerve fibers. The fibers of the neural network were mainly located on the superior (95.83%) and inferior (91.66%) surfaces of the renal artery and they were sparsely interconnected by diagonal fibers. Polar arteries were present in 33.33% of cases and the renal nerve pattern for these was similar to that of the hilar arteries. Effective renal denervation needs to target the superior and inferior surfaces of the hilar and polar arteries, where the fibers of the neural network are present. Clin. Anat. 29:660-664, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. Changes in lumbosacral spinal nerve roots on diffusion tensor imaging in spinal stenosis

    OpenAIRE

    Zhong-jun Hou; Yong Huang; Zi-wen Fan; Xin-chun Li; Bing-yi Cao

    2015-01-01

    Lumbosacral degenerative disc disease is a common cause of lower back and leg pain. Conventional T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI) scans are commonly used to image spinal cord degeneration. However, these modalities are unable to image the entire lumbosacral spinal nerve roots. Thus, in the present study, we assessed the potential of diffusion tensor imaging (DTI) for quantitative assessment of compressed lumbosacral spinal nerve roots. Subjects were 20 young healthy v...

  7. Optimal imaging parameters to visualize lumbar spinal nerve roots in MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yamato, Hidetada; Takahashi, Toshiyuki; Funata, Tomonari; Nitta, Masaru; Nakazawa, Yasuo [Showa Univ., Tokyo (Japan). Hospital

    2001-05-01

    Radiculopathy due to lumber spine disorders is diagnosed mainly by radiculography. Recent advances in MRI have enabled non-invasive visualization of the lumbar nerve roots. Fifty normal volunteers were evaluated for optimal imaging angle to visualize the lumbar nerve roots and optimal imaging sequences. Results showed that in the coronal oblique plane, angles that visualized the nerve roots best were L4 17, L5 29.6, and S1 36.8. In the left sagittal oblique plane, the angles were L4 17.9, L5 21.4, and S1 12.6, and in the right sagittal oblique plane, L4 16.3, L5 19.4 and S1 12.6. SPGR showed the best results both in CNR values and visually. In summary, the optimal angle by which to visualize the lumbar spinal nerve roots increased as the roots became more caudal, except for S1 of the sagittal oblique plane, where individual variations were pronounced. SPGR was the best sequence for visualizing the nerve roots. (author)

  8. Retrospective case series of the imaging findings of facial nerve hemangioma.

    Science.gov (United States)

    Yue, Yunlong; Jin, Yanfang; Yang, Bentao; Yuan, Hui; Li, Jiandong; Wang, Zhenchang

    2015-09-01

    The aim was to compare high-resolution computed tomography (HRCT) and thin-section magnetic resonance imaging (MRI) findings of facial nerve hemangioma. The HRCT and MRI characteristics of 17 facial nerve hemangiomas diagnosed between 2006 and 2013 were retrospectively analyzed. All patients included in the study suffered from a space-occupying lesion of soft tissues at the geniculate ganglion fossa. Affected nerve was compared for size and shape with the contralateral unaffected nerve. HRCT showed irregular expansion and broadening of the facial nerve canal, damage of the bone wall and destruction of adjacent bone, with "point"-like or "needle"-like calcifications in 14 cases. The average CT value was 320.9 ± 141.8 Hu. Fourteen patients had a widened labyrinthine segment; 6/17 had a tympanic segment widening; 2/17 had a greater superficial petrosal nerve canal involvement, and 2/17 had an affected internal auditory canal (IAC) segment. On MRI, all lesions were significantly enhanced due to high blood supply. Using 2D FSE T2WI, the lesion detection rate was 82.4 % (14/17). 3D fast imaging employing steady-state acquisition (3D FIESTA) revealed the lesions in all patients. HRCT showed that the average number of involved segments in the facial nerve canal was 2.41, while MRI revealed an average of 2.70 segments (P facial nerve hemangioma were typical, revealing irregular masses growing along the facial nerve canal, with calcifications and rich blood supply. Thin-section enhanced MRI was more accurate in lesion detection and assessment compared with HRCT.

  9. External light activates hair follicle stem cells through eyes via an ipRGC-SCN-sympathetic neural pathway.

    Science.gov (United States)

    Fan, Sabrina Mai-Yi; Chang, Yi-Ting; Chen, Chih-Lung; Wang, Wei-Hung; Pan, Ming-Kai; Chen, Wen-Pin; Huang, Wen-Yen; Xu, Zijian; Huang, Hai-En; Chen, Ting; Plikus, Maksim V; Chen, Shih-Kuo; Lin, Sung-Jan

    2018-06-29

    Changes in external light patterns can alter cell activities in peripheral tissues through slow entrainment of the central clock in suprachiasmatic nucleus (SCN). It remains unclear whether cells in otherwise photo-insensitive tissues can achieve rapid responses to changes in external light. Here we show that light stimulation of animals' eyes results in rapid activation of hair follicle stem cells with prominent hair regeneration. Mechanistically, light signals are interpreted by M1-type intrinsically photosensitive retinal ganglion cells (ipRGCs), which signal to the SCN via melanopsin. Subsequently, efferent sympathetic nerves are immediately activated. Increased norepinephrine release in skin promotes hedgehog signaling to activate hair follicle stem cells. Thus, external light can directly regulate tissue stem cells via an ipRGC-SCN autonomic nervous system circuit. Since activation of sympathetic nerves is not limited to skin, this circuit can also facilitate rapid adaptive responses to external light in other homeostatic tissues.

  10. Recovery of colonic transit following extrinsic nerve damage in rats.

    Science.gov (United States)

    Ridolfi, Timothy J; Tong, Wei Dong; Kosinski, Lauren; Takahashi, Toku; Ludwig, Kirk A

    2011-06-01

    Injury to pelvic sympathetic and parasympathetic nerves from surgical and obstetrical trauma has long been cited as a cause for abnormal colorectal motility in humans. Using a rat model, acute transaction of these extrinsic nerves has been shown to effect colorectal motility. The aim of this study is to determine in a rat model how transection of these extrinsic nerves affects colonic transit over time. Eighty-two Sprague-Dawley rats underwent placement of a tunneled catheter into the proximal colon. Bilateral hypogastric, pelvic nerves (HGN and PN) or both were transected in 66 rats. The remaining 16 rats received a sham operation. Colonic transit was evaluated at postoperative days (PODs) 1, 3, and 7 by injecting and calculating the geometric center (GC) of the distribution of (51)Cr after 3 h of propagation. At POD 1, transection of PNs significantly delayed colonic transit (GC = 4.9, p < 0.05), while transection of HGNs (GC = 8.5, p < 0.05) or transection of both nerves (GC = 7.8, p < 0.05) significantly accelerated colonic transit, when compared with sham operation (GC = 6.0). A significant trend toward recovery was noted in both the HGN and PN transection groups at POD 7. Damage to the extrinsic sympathetic and/or parasympathetic PNs affects colonic transit acutely. These changes in large bowel motor function normalize over time implicating a compensatory mechanism within the bowel itself.

  11. Novel Approaches for the Treatment of the Patient with Resistant Hypertension: Renal Nerve Ablation

    Science.gov (United States)

    Gulati, Vinay; White, William B.

    2013-01-01

    Sympathetic innervation of the kidneys plays a major role in the pathogenesis of hypertension through modulation of renin secretion, glomerular filtration rate and renal absorption of sodium. Targeted interventions for renal nerve ablation are being developed for treatment of drug resistant hypertension in the USA and rest of the world. Early studies with the use of radiofrequency based renal denervation systems have shown encouraging results with significant reduction of blood pressure in patients inadequately controlled despite nearly maximal drug therapy regimens. Thus far, the renal denervation procedure has been associated with minimal side effects. Long term efficacy and safety beyond 3 years needs to be determined for renal nerve ablation. This review focuses on the physiology of the renal sympathetic system, the rationale for renal nerve ablation and current evidence in support of the available therapeutic renal denervation systems. PMID:24244757

  12. Cranial nerve assessment in cavernous sinus tumors with contrast-enhanced 3D fast-imaging employing steady-state acquisition MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, Shiori; Aoki, Shigeki; Ohtomo, Kuni [University of Tokyo, Department of Radiology, Graduate School of Medicine, Bunkyo-ku, Tokyo (Japan)

    2009-07-15

    The purpose of this study is to apply contrast-enhanced 3D fast-imaging employing steady-state acquisition (3D-FIESTA) imaging to the evaluation of cranial nerves (CN) in patients with cavernous sinus tumors. Contrast-enhanced 3D-FIESTA images were acquired from ten patients with cavernous sinus tumors with a 3-T unit. In all cases, the trigeminal nerve with tumor involvement was easily identified in the cavernous portions. Although oculomotor and abducens nerves were clearly visualized against the tumor area with intense contrast enhancement, they were hardly identifiable within the area lacking contrast enhancement. The trochlear nerve was visualized in part, but not delineated as a linear structure outside of the lesion. Contrast-enhanced 3D-FIESTA can be useful in the assessment of cranial nerves in and around the cavernous sinus with tumor involvement. (orig.)

  13. Cranial nerve assessment in cavernous sinus tumors with contrast-enhanced 3D fast-imaging employing steady-state acquisition MR imaging

    International Nuclear Information System (INIS)

    Amemiya, Shiori; Aoki, Shigeki; Ohtomo, Kuni

    2009-01-01

    The purpose of this study is to apply contrast-enhanced 3D fast-imaging employing steady-state acquisition (3D-FIESTA) imaging to the evaluation of cranial nerves (CN) in patients with cavernous sinus tumors. Contrast-enhanced 3D-FIESTA images were acquired from ten patients with cavernous sinus tumors with a 3-T unit. In all cases, the trigeminal nerve with tumor involvement was easily identified in the cavernous portions. Although oculomotor and abducens nerves were clearly visualized against the tumor area with intense contrast enhancement, they were hardly identifiable within the area lacking contrast enhancement. The trochlear nerve was visualized in part, but not delineated as a linear structure outside of the lesion. Contrast-enhanced 3D-FIESTA can be useful in the assessment of cranial nerves in and around the cavernous sinus with tumor involvement. (orig.)

  14. Transient sixth cranial nerve palsy following orgasm abrogated by treatment with sympathomimetic amines.

    Science.gov (United States)

    Check, J H; Katsoff, B

    2014-01-01

    To describe a unique disorder where a transient 6th nerve palsy leading to diploplia following orgasm developed in a 28-year-old woman. This coincided with a weight gain of 100 pounds in a short time without a corresponding change in dietary habits. She was treated with the sympathomimetic amine dextroamphetamine sulfate. Indeed she immediately responded to treatment with dextroamphetamine sulfate sustained release capsules with complete resolution of the episodes of 6th nerve palsy following orgasm. The main importance of this case is that it suggests that orgasm causes a transient generalized decrease in sympathetic nervous system activity and that the achievement of an orgasm may require an increase in the sympathetic nervous system activity.

  15. High-resolution imaging of retinal nerve fiber bundles in glaucoma using adaptive optics scanning laser ophthalmoscopy.

    Science.gov (United States)

    Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Ueda-Arakawa, Naoko; Yoshida, Sachiko; Akagi, Tadamichi; Ikeda, Hanako Ohashi; Nonaka, Atsushi; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

    2013-05-01

    To detect pathologic changes in retinal nerve fiber bundles in glaucomatous eyes seen on images obtained by adaptive optics (AO) scanning laser ophthalmoscopy (AO SLO). Prospective cross-sectional study. Twenty-eight eyes of 28 patients with open-angle glaucoma and 21 normal eyes of 21 volunteer subjects underwent a full ophthalmologic examination, visual field testing using a Humphrey Field Analyzer, fundus photography, red-free SLO imaging, spectral-domain optical coherence tomography, and imaging with an original prototype AO SLO system. The AO SLO images showed many hyperreflective bundles suggesting nerve fiber bundles. In glaucomatous eyes, the nerve fiber bundles were narrower than in normal eyes, and the nerve fiber layer thickness was correlated with the nerve fiber bundle widths on AO SLO (P fiber layer defect area on fundus photography, the nerve fiber bundles on AO SLO were narrower compared with those in normal eyes (P optic disc, the nerve fiber bundle width was significantly lower, even in areas without nerve fiber layer defect, in eyes with glaucomatous eyes compared with normal eyes (P = .026). The mean deviations of each cluster in visual field testing were correlated with the corresponding nerve fiber bundle widths (P = .017). AO SLO images showed reduced nerve fiber bundle widths both in clinically normal and abnormal areas of glaucomatous eyes, and these abnormalities were associated with visual field defects, suggesting that AO SLO may be useful for detecting early nerve fiber bundle abnormalities associated with loss of visual function. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Sympathetic responses during saline infusion into the veins of an occluded limb.

    Science.gov (United States)

    Cui, Jian; McQuillan, Patrick; Moradkhan, Raman; Pagana, Charles; Sinoway, Lawrence I

    2009-07-15

    Animal studies have shown that the increased intravenous pressure stimulates the group III and IV muscle afferent fibres, and in turn induce cardiovascular responses. However, this pathway of autonomic regulation has not been examined in humans. The aim of this study was to examine the hypothesis that infusion of saline into the venous circulation of an arterially occluded vascular bed evokes sympathetic activation in healthy individuals. Blood pressure, heart rate, and muscle sympathetic nerve activity (MSNA) responses were assessed in 19 young healthy subjects during local infusion of 40 ml saline into a forearm vein in the circulatory arrested condition. From baseline (11.8 +/- 1.2 bursts min(-1)), MSNA increased significantly during the saline infusion (22.5 +/- 2.6 bursts min(-1), P Blood pressure also increased significantly during the saline infusion. Three control trials were performed during separate visits. The results from the control trial show that the observed MSNA and blood pressure responses were not due to muscle ischaemia. The present data show that saline infusion into the venous circulation of an arterially occluded vascular bed induces sympathetic activation and an increase in blood pressure. We speculate that the infusion under such conditions stimulates the afferent endings near the vessels, and evokes the sympathetic activation.

  17. Imaging features suggestive of a conjoined nerve root on routine axial MRI

    Energy Technology Data Exchange (ETDEWEB)

    Song, Su Jin; Lee, Joon Woo; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Gyeongi-do (Korea); Choi, Ja-Young; Hong, Sung Hwan; Kim, Na Ra [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea); Kim, Ki-Jeong; Chung, Sang-Ki; Kim, Hyun-Jib [Seoul National University Bundang Hospital, Department of Neurosurgery, Gyeongi-Do (Korea)

    2008-02-15

    The purpose of our study is to evaluate imaging features suggestive of a conjoined nerve root on routine axial MRI. Two radiologists and two surgeons retrospectively reviewed the MRI of three cases in which a conjoined nerve root was discovered during operation and found three suggestive signs on routine axial MR images: ''corner'' (asymmetric morphology of the anterolateral corner of the dural sac), ''fat crescent'' (intervening extradural fat between the asymmetric dura and the nerve root), and ''parallel'' signs (visualization of the entire parallel course of the nerve root at the disc level). Two radiologists prospectively found these signs during routine MRI interpretation sessions over a period of 6 months. If one or a combination of signs were noted on axial MR images, contiguous axial scans were additionally obtained. Three cases that were previously found during operations were also included. Prevalence and confidence scores for each sign were assessed on axial T1- and T2-weighted images. Twelve patients showed one or a combination of the three signs, 9 had contiguous axial MR scans. Five cases were confirmed by operation. The prevalence of the corner, fat crescent, and parallel signs were 12 out of 12 (100%), 6 out of 12 (50%), and 8 out of 12 (67.7%) on axial T1-weighted images. The overall diagnostic confidence was higher on T1- than on T2-weighted images (P < 0.05). On routine axial L-spine MRI, corner, fat crescent, and parallel signs are suggestive of and assist in the recognition of a conjoined nerve root. (orig.)

  18. Magnetic resonance imaging of peripheral nerve tumours in the upper extremity

    DEFF Research Database (Denmark)

    Nilsson, Jessica; Sandberg, Kristina; Søe Nielsen, Niels

    2009-01-01

    Clinical assessment and various diagnostic tools, particularly magnetic resonance imaging (MRI), of tumours of peripheral nerves are used to get an accurate diagnosis and to plan surgical intervention. Our purpose was to examine the usefulness of MRI in assessing nerve tumours in the upper...

  19. The imaging of abducens nerve in normal volunteers and palsy cases using 1.5T MRI 3-D CISS

    International Nuclear Information System (INIS)

    Takahashi, Mayu; Ezuka, Isamu; Kakinuma, Kenichi; Yamada, Haruyuki; Harada, Atsukuni; Kanazawa, Tsutomu

    2002-01-01

    The purpose of this study was to identify the cisternal segment of the abducens nerve and to investigate its anatomical features using three-dimensional Fourier transform constructive interference in steady-state (3-D CISS) sequence with a 1.5-tesla magnetic resonance (MR) imaging system. Images of abducens nerve palsy were also studied. Using this imaging system, the following procedures were performed to identify the abducens nerve. First, gray scale of the original images was inverted (inverted image). Second, Dollero's canal was identified, which contains the abducens nerve, and third, the nerve was followed to the root exit zone with a multiple-planar reconstruction method. Twenty-one volunteers and 3 patients with abducens nerve palsies participated in this study and following results were derived: all nerves in volunteers were clearly identified in the coronal and sagittal planes, the images closely resembled autopsy cases, seven nerves in asymptomatic cases were remarkably distorted by the vessels, and the cause of the palsy was not clear by their shapes in the images; this technique, however, can play a great role in evaluating abducens nerve palsy. (author)

  20. MR imaging findings of anterior interosseous nerve lesions

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Andrew J. [Royal Liverpool University Hospital, Department of Medical Imaging, Liverpool (United Kingdom); Salonen, David C. [University of Toronto, Toronto Western Hospital, Department of Medical Imaging, Toronto, Ontario (Canada); Anastakis, Dimitri J. [University of Toronto, Toronto Western Hospital, Division of Plastic Surgery, Toronto, Ontario (Canada)

    2007-12-15

    To study and characterise the MR imaging findings of lesions of the anterior interosseous nerve (AIN). Magnetic resonance imaging (MRI) findings of the forearm of ten patients referred to our institution with suspected AIN lesions were retrospectively studied. Five healthy volunteers with normal forearm MRI findings formed a control group. Two musculoskeletal radiologists assessed the forearm musculature for oedema in the distribution of the AIN, median, posterior interosseous and radial nerves on T2-weighted (T2W) fat-saturated sequences. T1-weighted (T1W) images were assessed and graded for the presence of muscle atrophy and fatty involution. Six patients had undergone surgical exploration; five of these had surgically confirmed AIN compression. Four patients had diagnoses other than AIN compression made on imaging features. Of the cases of proven AIN compression, oedema within the pronator quadratus (PQ) muscle was identified in all cases. PQ atrophy and fatty involution were seen in three (43%) surgically confirmed cases. Cases 2 and 3 also demonstrated oedema in the flexor digitorum profundus (FDP)1 and FDP2 muscles. These cases also showed oedema in the flexor-carpi radialis (FCR) and FDP3/FDP4 muscles, respectively. The four cases of non-AIN compression demonstrated muscle oedema patterns that were atypical for the AIN distribution. They included a rupture of the flexor pollicis longus (FPL) tendon, brachial neuritis, amyotrophic lateral sclerosis and compression of the proximal median nerve. MRI is a useful investigation in the diagnostic workup of AIN syndrome. AIN syndrome is likely when there is diffuse oedema of AIN innervated muscles on T2W fat-saturated images. The most reliable sign of an AIN lesion is oedema within the PQ. Oedema in the flexor carpi radialis, FDP3 and FDP4, although not in the classical distribution of the AIN, does not preclude the diagnosis of AIN syndrome. (orig.)

  1. MR imaging findings of anterior interosseous nerve lesions

    International Nuclear Information System (INIS)

    Dunn, Andrew J.; Salonen, David C.; Anastakis, Dimitri J.

    2007-01-01

    To study and characterise the MR imaging findings of lesions of the anterior interosseous nerve (AIN). Magnetic resonance imaging (MRI) findings of the forearm of ten patients referred to our institution with suspected AIN lesions were retrospectively studied. Five healthy volunteers with normal forearm MRI findings formed a control group. Two musculoskeletal radiologists assessed the forearm musculature for oedema in the distribution of the AIN, median, posterior interosseous and radial nerves on T2-weighted (T2W) fat-saturated sequences. T1-weighted (T1W) images were assessed and graded for the presence of muscle atrophy and fatty involution. Six patients had undergone surgical exploration; five of these had surgically confirmed AIN compression. Four patients had diagnoses other than AIN compression made on imaging features. Of the cases of proven AIN compression, oedema within the pronator quadratus (PQ) muscle was identified in all cases. PQ atrophy and fatty involution were seen in three (43%) surgically confirmed cases. Cases 2 and 3 also demonstrated oedema in the flexor digitorum profundus (FDP)1 and FDP2 muscles. These cases also showed oedema in the flexor-carpi radialis (FCR) and FDP3/FDP4 muscles, respectively. The four cases of non-AIN compression demonstrated muscle oedema patterns that were atypical for the AIN distribution. They included a rupture of the flexor pollicis longus (FPL) tendon, brachial neuritis, amyotrophic lateral sclerosis and compression of the proximal median nerve. MRI is a useful investigation in the diagnostic workup of AIN syndrome. AIN syndrome is likely when there is diffuse oedema of AIN innervated muscles on T2W fat-saturated images. The most reliable sign of an AIN lesion is oedema within the PQ. Oedema in the flexor carpi radialis, FDP3 and FDP4, although not in the classical distribution of the AIN, does not preclude the diagnosis of AIN syndrome. (orig.)

  2. Implantable electrode for recording nerve signals in awake animals

    Science.gov (United States)

    Ninomiya, I.; Yonezawa, Y.; Wilson, M. F.

    1976-01-01

    An implantable electrode assembly consisting of collagen and metallic electrodes was constructed to measure simultaneously neural signals from the intact nerve and bioelectrical noises in awake animals. Mechanical artifacts, due to bodily movement, were negligibly small. The impedance of the collagen electrodes, measured in awake cats 6-7 days after implantation surgery, ranged from 39.8-11.5 k ohms at a frequency range of 20-5 kHz. Aortic nerve activity and renal nerve activity, measured in awake conditions using the collagen electrode, showed grouped activity synchronous with the cardiac cycle. Results indicate that most of the renal nerve activity was from postganglionic sympathetic fibers and was inhibited by the baroceptor reflex in the same cardiac cycle.

  3. Multimodal imaging in neurofibromatosis type 1-associated nerve sheath tumors

    International Nuclear Information System (INIS)

    Salamon, J.; Adam, G.; Mautner, V.F.; Derlin, T.

    2015-01-01

    Neurofibromatosis type 1 (NF1) is a neurogenetic disorder. Individuals with NF1 may develop a variety of benign and malignant tumors of which peripheral nerve sheath tumors represent the most frequent entity. Plexiform neurofibromas may demonstrate a locally destructive growth pattern, may cause severe symptoms and may undergo malignant transformation into malignant peripheral nerve sheath tumors (MPNSTs). Whole-body magnetic resonance imaging (MRI) represents the reference standard for detection of soft tissue tumors in NF1. It allows for identification of individuals with plexiform neurofibromas, for assessment of local tumor extent, and for evaluation of whole-body tumor burden on T2-weighted imaging. Multiparametric MRI may provide a comprehensive characterization of different tissue properties of peripheral nerve sheath tumors, and may identify parameters associated with malignant transformation. Due to the absence of any radiation exposure, whole-body MRI may be used for serial follow-up of individuals with plexiform neurofibromas. 18 F-fluorodeoxyglucose positron-emission-tomography (FDG PET/CT) allows a highly sensitive and specific detection of MPNST, and should be used in case of potential malignant transformation of a peripheral nerve sheath tumor. PET/CT provides a sensitive whole-body tumor staging. The use of contrast-enhanced CT for diagnosis of peripheral nerve sheath tumors is limited to special indications. To obtain the most precise readings, optimized examination protocols and dedicated radiologists and nuclear medicine physicians familiar with the complex and variable morphologies of peripheral nerve sheath tumors are required.

  4. Imaging of cranial nerves with three-dimensional high resolution diffusion-weighted MR sequence based on SSFP technique

    International Nuclear Information System (INIS)

    Zhang Zhongwei; Chen Yingming; Meng Quanfei

    2008-01-01

    Objective: To depict the normal anatomy of cranial nerves in detail and define the exact relationships between cranial nerves and adjacent structures with three-dimensional high resolution diffusion-weighted MR sequence based on SSFP technique (3D DW-SSFP). Methods: 3D DW- SSFP sequence was performed and axial images were obtained in 12 healthy volunteers Post-processing techniques were used to generate images of cranial nerves, and the images acquired were compared with anatomical sections and diagrams of textbook. Results: In all subjects, 3D DW-SSFP sequence could produce homogeneous images and high contrast between the cranial nerves and other solid structures. The intracranial portions of all cranial nerves except olfactory nerve were identified; the extracranial portions of nerve Ⅱ-Ⅻ were identified in all subjects bilaterally. Conclusion: The 3D DW-SSFP sequence can characterize the normal MR appearance of cranial nerves and its branches and the ability to define the nerves may provide greater sensitivity and specificity in detecting abnormalities of craniofacial structure. (authors)

  5. Ulnar nerve damage (image)

    Science.gov (United States)

    The ulnar nerve originates from the brachial plexus and travels down arm. The nerve is commonly injured at the elbow because of elbow fracture or dislocation. The ulnar nerve is near the surface of the body where ...

  6. elPBN neurons regulate rVLM activity through elPBN-rVLM projections during activation of cardiac sympathetic afferent nerves.

    Science.gov (United States)

    Guo, Zhi-Ling; Longhurst, John C; Tjen-A-Looi, Stephanie C; Fu, Liang-Wu

    2016-08-01

    The external lateral parabrachial nucleus (elPBN) within the pons and rostral ventrolateral medulla (rVLM) contributes to central processing of excitatory cardiovascular reflexes during stimulation of cardiac sympathetic afferent nerves (CSAN). However, the importance of elPBN cardiovascular neurons in regulation of rVLM activity during CSAN activation remains unclear. We hypothesized that CSAN stimulation excites the elPBN cardiovascular neurons and, in turn, increases rVLM activity through elPBN-rVLM projections. Compared with controls, in rats subjected to microinjection of retrograde tracer into the rVLM, the numbers of elPBN neurons double-labeled with c-Fos (an immediate early gene) and the tracer were increased after CSAN stimulation (P neurons contain vesicular glutamate transporter 3. In cats, epicardial bradykinin and electrical stimulation of CSAN increased the activity of elPBN cardiovascular neurons, which was attenuated (n = 6, P neurons in the elPBN and rVLM sequentially through a monosynaptic (glutamatergic) excitatory elPBN-rVLM pathway. Copyright © 2016 the American Physiological Society.

  7. Femoral nerve damage (image)

    Science.gov (United States)

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  8. elPBN neurons regulate rVLM activity through elPBN-rVLM projections during activation of cardiac sympathetic afferent nerves

    Science.gov (United States)

    Longhurst, John C.; Tjen-A-Looi, Stephanie C.; Fu, Liang-Wu

    2016-01-01

    The external lateral parabrachial nucleus (elPBN) within the pons and rostral ventrolateral medulla (rVLM) contributes to central processing of excitatory cardiovascular reflexes during stimulation of cardiac sympathetic afferent nerves (CSAN). However, the importance of elPBN cardiovascular neurons in regulation of rVLM activity during CSAN activation remains unclear. We hypothesized that CSAN stimulation excites the elPBN cardiovascular neurons and, in turn, increases rVLM activity through elPBN-rVLM projections. Compared with controls, in rats subjected to microinjection of retrograde tracer into the rVLM, the numbers of elPBN neurons double-labeled with c-Fos (an immediate early gene) and the tracer were increased after CSAN stimulation (P < 0.05). The majority of these elPBN neurons contain vesicular glutamate transporter 3. In cats, epicardial bradykinin and electrical stimulation of CSAN increased the activity of elPBN cardiovascular neurons, which was attenuated (n = 6, P < 0.05) after blockade of glutamate receptors with iontophoresis of kynurenic acid (Kyn, 25 mM). In separate cats, microinjection of Kyn (1.25 nmol/50 nl) into the elPBN reduced rVLM activity evoked by both bradykinin and electrical stimulation (n = 5, P < 0.05). Excitation of the elPBN with microinjection of dl-homocysteic acid (2 nmol/50 nl) significantly increased basal and CSAN-evoked rVLM activity. However, the enhanced rVLM activity induced by dl-homocysteic acid injected into the elPBN was reversed following iontophoresis of Kyn into the rVLM (n = 7, P < 0.05). These data suggest that cardiac sympathetic afferent stimulation activates cardiovascular neurons in the elPBN and rVLM sequentially through a monosynaptic (glutamatergic) excitatory elPBN-rVLM pathway. PMID:27225950

  9. Clinical evaluation of 123I-MIBG for assessment of sympathetic nervous system in the heart

    International Nuclear Information System (INIS)

    Hirosawa, Koushitiro; Tanaka, Takeshi; Hisada, Kin-ichi; Bunko, Hisashi.

    1991-01-01

    Multi-center clinical trial of 123 I-metaiodobenzylguanidine ( 123 I-MIBG) was carried out to assess its utility as a scintigraphic imaging agent reflecting sympathetic neuronal function in cardiovascular field. Studies were performed on patients with heart diseases of three categories, myocardial infarction, angina pectoris and cardiomyopathy. Scintigraphic images, reflecting sympathetic neuronal function, were obtained with 123 I-MIBG from all of those categories of patients and the efficacy of the imaging was revealed in 781 (95.0%) out of 822 patients. In some patients abnormality was suggested in sympathetic neuronal function with 123 I-MIBG imaging, in spite of normal findings with myocardial perfusion scintigraphy by 201 TlCl. In all 981 patients studied with 123 I-MIBG, there have been no severe adverse reactions, except complaints of burning on injection site of the agent or nausea, ect. from 4 patients. We conclude that 123 I-MIBG imaging is one of the effective tools for diagnostic use reflecting topical sympathetic neuronal function in the heart, judging from its safety and efficacy. (author)

  10. Renal sympathetic denervation for resistant hypertension.

    Science.gov (United States)

    Froeschl, Michael; Hadziomerovic, Adnan; Ruzicka, Marcel

    2013-05-01

    Resistant hypertension is an increasingly prevalent health problem associated with important adverse cardiovascular outcomes. The pathophysiology that underlies this condition involves increased function of both the sympathetic nervous system and the renin-angiotensin II-aldosterone system. A crucial link between these 2 systems is the web of sympathetic fibres that course within the adventitia of the renal arteries. These nerves can be targeted by applying radiofrequency energy from the lumen of the renal arteries to renal artery walls (percutaneous renal sympathetic denervation [RSD]), an approach that has attracted great interest. This paper critically reviews the evidence supporting the use of RSD. Small studies suggest that RSD can produce dramatic blood pressure reductions: In the randomized Symplicity HTN-2 trial of 106 patients, the mean fall in blood pressure at 6 months in patients who received the treatment was 32/12 mm Hg. However, there are limitations to the evidence for RSD in the treatment of resistant hypertension. These include the small number of patients studied; the lack of any placebo-controlled evidence; the fact that blood pressure outcomes were based on office assessments, as opposed to 24-hour ambulatory monitoring; the lack of longer-term efficacy data; and the lack of long-term safety data. Some of these concerns are being addressed in the ongoing Renal Denervation in Patients With Uncontrolled Hypertension (Symplicity HTN-3) trial. The first percutaneous RSD system was approved by Health Canada in the spring of 2012. But until more and better-quality data are available, this procedure should generally be reserved for those patients whose resistant hypertension is truly uncontrolled. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  11. The crosstalk between the kidney and the central nervous system: the role of renal nerves in blood pressure regulation.

    Science.gov (United States)

    Nishi, Erika E; Bergamaschi, Cássia T; Campos, Ruy R

    2015-04-20

    What is the topic of this review? This review describes the role of renal nerves as the key carrier of signals from the kidneys to the CNS and vice versa; the brain and kidneys communicate through this carrier to maintain homeostasis in the body. What advances does it highlight? Whether renal or autonomic dysfunction is the predominant contributor to systemic hypertension is still debated. In this review, we focus on the role of the renal nerves in a model of renovascular hypertension. The sympathetic nervous system influences the renal regulation of arterial pressure and body fluid composition. Anatomical and physiological evidence has shown that sympathetic nerves mediate changes in urinary sodium and water excretion by regulating the renal tubular water and sodium reabsorption throughout the nephron, changes in the renal blood flow and the glomerular filtration rate by regulating the constriction of renal vasculature, and changes in the activity of the renin-angiotensin system by regulating the renin release from juxtaglomerular cells. Additionally, renal sensory afferent fibres project to the autonomic central nuclei that regulate blood pressure. Hence, renal nerves play a key role in the crosstalk between the kidneys and the CNS to maintain homeostasis in the body. Therefore, the increased sympathetic nerve activity to the kidney and the renal afferent nerve activity to the CNS may contribute to the outcome of diseases, such as hypertension. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

  12. Device-based approaches for renal nerve ablation for hypertension and beyond

    OpenAIRE

    Alicia Ann Thorp; Markus Peter Schlaich; Markus Peter Schlaich

    2015-01-01

    Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy...

  13. Microanatomical and immunohistochemical study of the human lateral antebrachial cutaneous nerve of forearm at the antecubital fossa and its clinical implications.

    Science.gov (United States)

    Marx, S Chakravarthy; Kumar, Pramod; Dhalapathy, S; Prasad, Keerthana; Marx, C Anitha

    2010-09-01

    Changes in the intraneural anatomy with age can cause poor prognosis of nerve repair in patients after nerve injury. The occurrence of Complex Regional Pain Syndrome-Type II, secondary to peripheral nerve injury, is common. The purpose of this study is to asses changes in cross-sectional anatomy of the lateral antebrachial cutaneous nerve of forearm (LCNF) at the antecubital fossa in the fascicular, nonfascicular components (adipose and nonadipose tissue), and sympathetic fibers area with respect to age. For the purpose of the study, 32 human (37-88 years) fresh cadaveric LCNF were collected from left-antecubital fossae and processed for histological, morphometric analysis [total cross-sectional (Asc), fascicular (Af), and nonfascicular area (Anonf)], and immunohistochemical method (tyrosine hydroxylase) for sympathetic fibers. The LCNF's average total cross-sectional area was 3.024 mm(2), and fascicular area was 0.582 mm(2). The average number of fascicles per mm(2) was 3.09. The cross-sectional area in the nerve was mainly occupied by nonfascicular connective tissue (80.75%). There was increased adipose tissue deposition (48.48% of Asc) and decreased collagen fibers (32.24% of Asc) in interfascicular domains without any definite relationship with age. The average sympathetic fiber area was 0.026 mm(2) within the nerve fascicular area without any correlation with age. In LCNF, there was more adipose tissue and less collagen fibers deposition in the interfascicular domains of all age cases, and this may act as an obstacle for nerve fiber regeneration on using LCNF as an interpositional nerve graft.

  14. Tibial nerve (image)

    Science.gov (United States)

    ... nerve is commonly injured by fractures or other injury to the back of the knee or the lower leg. It may be affected by systemic diseases such as diabetes mellitus. The nerve can also be damaged by pressure from a tumor, abscess, or bleeding into the ...

  15. Magnetic resonance imaging research progress on brain functional reorganization after peripheral nerve injury

    International Nuclear Information System (INIS)

    Wang Weiwei; Liu Hanqiu

    2013-01-01

    In the recent years, with the development of functional magnetic resonance imaging technology the brain plasticity and functional reorganization are hot topics in the central nervous system imaging studies. Brain functional reorganization and rehabilitation after peripheral nerve injury may have certain regularity. In this paper, the progress of brain functional magnetic resonance imaging technology and its applications in the world wide clinical and experimental researches of the brain functional reorganization after peripheral nerve injury is are reviewed. (authors)

  16. SYMPATHETIC NEURAL AND HEMODYNAMIC RESPONSES DURING COLD PRESSOR TEST IN ELDERLY BLACKS AND WHITES

    Science.gov (United States)

    Okada, Yoshiyuki; Jarvis, Sara S.; Best, Stuart A.; Edwards, Jeffrey G.; Hendrix, Joseph M.; Adams-Huet, Beverley; Vongpatanasin, Wanpen; Levine, Benjamin D.; Fu, Qi

    2016-01-01

    The sympathetic response during the cold pressor test (CPT) has been reported to be greater in young blacks than whites, especially in those with a family history of hypertension. Since blood pressure (BP) increases with age, we evaluated whether elderly blacks have greater sympathetic activation during CPT than age-matched whites. BP, heart rate (HR), cardiac output (Qc), and muscle sympathetic nerve activity (MSNA) were measured during supine baseline, 2-min CPT, and 3-min recovery in 47 elderly [68±7 (SD) yrs] volunteers (12 blacks, 35 whites). Baseline BP, HR, Qc, or MSNA did not differ between races. Systolic and diastolic BP (DBP) and HR increased during CPT (all P0.05). Qc increased during CPT and up to 30 sec of recovery in both groups, but was lower in blacks than whites. MSNA increased during CPT in both groups (both P<0.001); the increase in burst frequency was similar between groups, while the increase in total activity was smaller in blacks (P=0.030 for interaction). Peak change (Δ) in DBP was correlated with Δ total activity at 1 min into CPT in both blacks (r=0.78, P=0.003) and whites (r=0.43, P=0.009), while the slope was significantly greater in blacks (P=0.007). Thus, elderly blacks have smaller sympathetic and central hemodynamic (e.g., Qc) responses, but a greater pressor response for a given sympathetic activation during CPT than elderly whites. This response may stem from augmented sympathetic vascular transduction, greater sympathetic activation to other vascular bed(s), and/or enhanced non-adrenergically mediated vasoconstriction in elderly blacks. PMID:27021009

  17. Distribution of lymphatic tissues and autonomic nerves in supporting ligaments around the cervix uteri.

    Science.gov (United States)

    Zhang, Jianping; Feng, Lanlan; Lu, Yi; Guo, Dongxia; Xi, Tengteng; Wang, Xiaochun

    2013-05-01

    To investigate the distribution of lymphatic tissues and nerves in the supporting ligaments around the cervix uteri for their tomographical relationship, 9 adult female cadavers were used in this study. Following the incision of all supporting ligaments around the cervix, hematoxylin and esosin (H&E) and immunohistochemical staining of various sections of these ligaments was performed to enable the distribution of lymph tissues and autonomic nerves to be observed. Four lymph nodes were identified in three cadaver specimens. Three lymph nodes were present at a distance of 2.0 cm from the cervix in the cranial side of the cardinal ligaments (CLs), and one lymph node was located at a distance of 4.0 cm from the cervix in the cranial side of the uterosacral ligament (USL). The lymphatic vessels were dispersed in the CLs, scattered in the cervical side of the USLs, and occasionally distributed in the vesicouterine ligaments (VULs). In the CLs, parasympathetic nerves were located at the pelvic lateral wall and went downwards and medially into the cervix, while sympathetic fibers were located in the middle and lower parts of the ligaments. In the USLs, the autonomic nerves, which consisted primarily of sympathetic fibers, went downwards and laterally from the pelvic wall to the cervix. In the VULs, parasympathetic and sympathetic nerves were located in the inner sides of the vesical veins in the deep layers of the ligaments. It is concluded that there are few lymphatic tissues in the supporting ligaments around the cervix uteri, and that nerve‑sparing radical hysterectomy (NSRH) may be a safe method for the treatment of early‑stage cervical cancer.

  18. Nerve endings in the heart of teleosts.

    Science.gov (United States)

    Kumar, S

    1979-01-01

    The nerve endings in the heart of fishes were studied using silver impregnation techniques. The heart chambers are profusely innervated by the sympathetic, parasympathetic (vagal) and postganglionic fibers of the intracardiac ganglia situated at the sinuatrial and the atrioventricular junctions. The plexuses are composed of medullated and nonmedullated fibers. The nerve fibers generally end freely and are slightly branched or unbranched terminations of myelinated and unmyelinated fibers. Moreover, a few nerve fibers end redundant in the form of end-rings, bulb-like, bush-like, club-shaped end end-coil like structures. The complex unencapsulated types of endings are also found in the myocardium of the atrium and the ventricle. The encapsulated endings (Vater-Pacinian; Krause end-bulb) could not be observed.

  19. Preoperative Visualization of Cranial Nerves in Skull Base Tumor Surgery Using Diffusion Tensor Imaging Technology.

    Science.gov (United States)

    Ma, Jun; Su, Shaobo; Yue, Shuyuan; Zhao, Yan; Li, Yonggang; Chen, Xiaochen; Ma, Hui

    2016-01-01

    To visualize cranial nerves (CNs) using diffusion tensor imaging (DTI) with special parameters. This study also involved the evaluation of preoperative estimates and intraoperative confirmation of the relationship between nerves and tumor by verifying the accuracy of visualization. 3T magnetic resonance imaging scans including 3D-FSPGR, FIESTA, and DTI were used to collect information from 18 patients with skull base tumor. DTI data were integrated into the 3D slicer for fiber tracking and overlapped anatomic images to determine course of nerves. 3D reconstruction of tumors was achieved to perform neighboring, encasing, and invading relationship between lesion and nerves. Optic pathway including the optic chiasm could be traced in cases of tuberculum sellae meningioma and hypophysoma (pituitary tumor). The oculomotor nerve, from the interpeduncular fossa out of the brain stem to supraorbital fissure, was clearly visible in parasellar meningioma cases. Meanwhile, cisternal parts of trigeminal nerve and abducens nerve, facial nerve were also imaged well in vestibular schwannomas and petroclival meningioma cases. The 3D-spatial relationship between CNs and skull base tumor estimated preoperatively by tumor modeling and tractography corresponded to the results determined during surgery. Supported by DTI and 3D slicer, preoperative 3D reconstruction of most CNs related to skull base tumor is feasible in pathological circumstances. We consider DTI Technology to be a useful tool for predicting the course and location of most CNs, and syntopy between them and skull base tumor.

  20. The imaging manifestation of intracranial schwannomas not arising from cranial nerves

    International Nuclear Information System (INIS)

    Luo Boning; Sun Gengxi; Liang Kangfu

    2003-01-01

    Objective: To report 4 cases of operation-confirmed intracranial schwannomas not arising from cranial nerves, and to discuss the histogenesis and CT and MRI manifestation combining with the literature. Methods: CT and MRI findings of these 4 intracranial schwannomas were analyzed retrospectively and their pathologic characteristics were reviewed. Results: The tumors demonstrated low-iso mixed density with necrotic and cystic areas. Large degeneration even became the prominent characteristics on CT scan. Low-signal to iso-signal intensity on T 1 -weighted images and heterogeneous high-signal intensity on T 2 -weighted images were revealed. The solid portion and the wall of the tumors were moderately enhanced on enhanced CT and MRI scans. Hematoxylin and eosin-stained sections showed two corresponding histological patterns: Antoni Type A and Antoni Type B pattern. The tumor cells exhibited a strong positive staining pattern for s-100 protein. Conclusion: The imaging manifestations of these tumors were similar to that of cranial nerve schwannomas except that the former had higher cystic degeneration rate. We should take that diagnosis into consideration when the mass is not located on cranial nerve but its image feature resembles schwannomas

  1. Effects of cilnidipine on sympathetic nerve activity and cardiorenal function in hypertensive patients with type 2 diabetes mellitus: association with BNP and aldosterone levels.

    Science.gov (United States)

    Tanaka, Masami; Sekioka, Risa; Nishimura, Takeshi; Ichihara, Atsuhiro; Itoh, Hiroshi

    2014-12-01

    Hypertension stimulates the sympathetic nervous system and this phenomenon is exacerbated by diabetes mellitus. We investigated the effects of cilnidipine, an N/L-type calcium channel blocker, on aspects of this system in patients with type 2 diabetes mellitus. In 33 hypertensive patients with type 2 diabetes mellitus treated with a calcium channel blocker other than cilnidipine, we evaluated the influence of switching to cilnidipine on blood pressure, heart rate, catecholamine, plasma renin and aldosterone concentration, brain natriuretic peptide, urine liver-type fatty acid binding protein, and urinary albumin excretion ratio in the same patients by a cross-over design. Other biochemical parameters were also evaluated. Switching to cilnidipine did not change blood pressure but caused reduction in catecholamine concentrations in blood and urine and plasma aldosterone concentration, accompanied by significant reduction in brain natriuretic peptide, urine liver-type fatty acid binding protein, and albumin excretion ratio. These parameters other than brain natriuretic peptide were significantly increased after cilnidipine was changed to the original calcium channel blocker. In 33 hypertensive patients with type 2 diabetes mellitus, compared to other calcium channel blockers, cilnidipine suppressed sympathetic nerve activity and aldosterone, and significantly improved markers of cardiorenal disorders. Therefore, cilnidipine may be an important calcium channel blocker for use in combination with renin-angiotensin-aldosterone system inhibitors when dealing with hypertension complicated with diabetes mellitus. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Sequential imaging of intraneural sciatic nerve endometriosis provides insight into symptoms of cyclical sciatica.

    Science.gov (United States)

    Capek, Stepan; Amrami, Kimberly K; Howe, Benjamin M; Collins, Mark S; Sandroni, Paola; Cheville, John C; Spinner, Robert J

    2016-03-01

    Endometriosis of the nerve often remains an elusive diagnosis. We report the first case of intraneural lumbosacral plexus endometriosis with sequential imaging at different phases of the menstrual cycle: during the luteal phase and menstruation. Compared to the first examination, the examination performed during the patient's period revealed the lumbosacral plexus larger and hyperintense on T2-weighted imaging. The intraneural endometriosis cyst was also larger and showed recent hemorrhage. Additionally, this case represents another example of perineural spread of endometriosis from the uterus to the lumbosacral plexus along the autonomic nerves and then distally to the sciatic nerve and proximally to the spinal nerves.

  3. Early life stress sensitizes the renal and systemic sympathetic system in rats.

    Science.gov (United States)

    Loria, Analia S; Brands, Michael W; Pollock, David M; Pollock, Jennifer S

    2013-08-01

    We hypothesized that maternal separation (MS), an early life stress model, induces a sensitization of the sympathetic system. To test this hypothesis, we evaluated the renal and systemic sympathetic system in 12- to 14-wk-old male control or MS rats with the following parameters: 1) effect of renal denervation on conscious renal filtration capacity, 2) norepinephrine (NE) content in key organs involved in blood pressure control, and 3) acute systemic pressor responses to adrenergic stimulation or ganglion blockade. MS was performed by separating pups from their mothers for 3 h/day from day 2 to 14; controls were nonhandled littermates. Glomerular filtration rate (GFR) was examined in renal denervated (DnX; within 2 wk) or sham rats using I¹²⁵-iothalamate plasma clearance. MS-DnX rats showed significantly increased GFR compared with MS-SHAM rats (3.8 ± 0.4 vs. 2.4 ± 0.2 ml/min, respectively, P renal nerves regulate GFR in MS rats. NE content was significantly increased in organ tissues from MS rats (P renal and systemic sympathetic system. Conscious MS rats displayed a significantly greater increase in mean arterial pressure (MAP) in response to NE (2 μg/kg ip) and a greater reduction in MAP in response to mecamylamine (2 mg/kg ip, P renal and systemic sympathetic system ultimately impairing blood pressure regulation.

  4. Renal sympathetic nervous system and the effects of denervation on renal arteries.

    Science.gov (United States)

    Kannan, Arun; Medina, Raul Ivan; Nagajothi, Nagapradeep; Balamuthusamy, Saravanan

    2014-08-26

    Resistant hypertension is associated with chronic activation of the sympathetic nervous system resulting in various comorbidities. The prevalence of resistant hypertension is often under estimated due to various reasons. Activation of sympathetic nervous system at the renal- as well as systemic- level contributes to the increased level of catecholamines and resulting increase in the blood pressure. This increased activity was demonstrated by increased muscle sympathetic nerve activity and renal and total body noradrenaline spillover. Apart from the hypertension, it is hypothesized to be associated with insulin resistance, congestive heart failure and obstructive sleep apnea. Renal denervation is a novel procedure where the sympathetic afferent and efferent activity is reduced by various techniques and has been used successfully to treat drug-resistant hypertension improvement of various metabolic derangements. Renal denervation has the unique advantage of offering the denervation at the renal level, thus mitigating the systemic side effects. Renal denervation can be done by various techniques including radiofrequency ablation, ultrasound guided ablation and chemical ablation. Various trials evaluated the role of renal denervation in the management of resistant hypertension and have found promising results. More studies are underway to evaluate the role of renal denervation in patients presenting with resistant hypertension in different scenarios. Appropriate patient selection might be the key in determining the effectiveness of the procedure.

  5. Efficacy of B-Type Natriuretic Peptide Is Coupled to Phosphodiesterase 2A in Cardiac Sympathetic Neurons.

    Science.gov (United States)

    Li, Dan; Lu, Chieh-Ju; Hao, Guoliang; Wright, Hannah; Woodward, Lavinia; Liu, Kun; Vergari, Elisa; Surdo, Nicoletta C; Herring, Neil; Zaccolo, Manuela; Paterson, David J

    2015-07-01

    Elevated B-type natriuretic peptide (BNP) regulates cGMP-phosphodiesterase activity. Its elevation is regarded as an early compensatory response to cardiac failure where it can facilitate sympathovagal balance and cardiorenal homeostasis. However, recent reports suggest a paradoxical proadrenergic action of BNP. Because phosphodiesterase activity is altered in cardiovascular disease, we tested the hypothesis that BNP might lose its efficacy by minimizing the action of cGMP on downstream pathways coupled to neurotransmission. BNP decreased norepinephrine release from atrial preparations in response to field stimulation and also significantly reduced the heart rate responses to sympathetic nerve stimulation in vitro. Using electrophysiological recording and fluorescence imaging, BNP also reduced the depolarization evoked calcium current and intracellular calcium transient in isolated cardiac sympathetic neurons. Pharmacological manipulations suggested that the reduction in the calcium transient was regulated by a cGMP/protein kinase G pathway. Fluorescence resonance energy transfer measurements for cAMP, and an immunoassay for cGMP, showed that BNP increased cGMP, but not cAMP. In addition, overexpression of phosphodiesterase 2A after adenoviral gene transfer markedly decreased BNP stimulation of cGMP and abrogated the BNP responses to the calcium current, intracellular calcium transient, and neurotransmitter release. These effects were reversed on inhibition of phosphodiesterase 2A. Moreover, phosphodiesterase 2A activity was significantly elevated in stellate neurons from the prohypertensive rat compared with the normotensive control. Our data suggest that abnormally high levels of phosphodiesterase 2A may provide a brake against the inhibitory action of BNP on sympathetic transmission. © 2015 American Heart Association, Inc.

  6. Review of the State of Renal Nerve Ablation for Patients with Severe and Resistant Hypertension

    Science.gov (United States)

    Gulati, Vinay; White, William B.

    2013-01-01

    Through modulation of renin secretion, glomerular filtration rate and renal absorption of sodium, the sympathetic innervation of the kidneys plays an important role in the pathogenesis of hypertension. Renal nerve ablation technology is being developed for treatment of drug-treatment resistant hypertension worldwide. Preliminary research with the use of radiofrequency based renal denervation systems have demonstrated encouraging results with significant reduction of blood pressure in patients inadequately controlled despite nearly maximal drug therapy regimens. From work done thus far, the renal denervation procedure has not been associated with serious adverse effects. Long term efficacy and safety still needs to be established for renal nerve ablation. This review focuses on the impact of the renal sympathetic system on blood pressure regulation, the clinical rationale for renal nerve ablation in severe and drug-treatment resistant hypertension and current evidence from the more advanced renal denervation devices. PMID:23953998

  7. Normal and pathological findings for the facial nerve on magnetic resonance imaging

    International Nuclear Information System (INIS)

    Al-Noury, K.; Lotfy, A.

    2011-01-01

    Aim: To demonstrate the enhanced radiological anatomy and common pathological conditions of the facial nerve by using magnetic resonance imaging (MRI). Materials and methods: A retrospective review of the MRI findings of the facial nerve of 146 patients who visited a tertiary academic referral center was conducted. Results: The radiological anatomy of the facial nerve was well illustrated using MRI, as were most of the common pathological conditions of the facial nerve. Conclusions: Enhancement of the facial nerve in MRI should be correlated with the clinical data. Normal individuals can show enhancement of the tympanic or vertical segments of the facial nerve. Enhancement of the labyrinthine portion of the nerve is almost diagnostic of Bell's palsy. No specific enhancement patterns were observed for tumours or for infections of the middle or external ear. A larger population study is required for the accurate assessment of facial nerve enhancement in multiple sclerosis patients.

  8. Gd-DTPA-enhanced MR imaging in facial nerve paralysis

    International Nuclear Information System (INIS)

    Tien, R.D.; Dillon, W.P.

    1989-01-01

    GD-DTPA-enhanced MR imaging was used to evaluate 11 patients with facial nerve paralysis (five acute idiopathic facial palsy (Bell palsy), three chronic recurrent facial palsy, one acute facial palsy after local radiation therapy, one chronic facial dyskinesia, and one facial neuroma). In eight of 11 patients, there was marked enhancement of the infratemporal facial nerve from the labyrinthine segment to the stylomastoid foramen. Two patients had additional contrast enhancement in the internal auditory canal segment. In one patient, enhancement persisted (but to a lesser degree) 8 weeks after symptoms had resolved. In one patient, no enhancement was seen 15 months after resolution of Bell palsy. The facial neuroma was seen as a focal nodular enhancement in the mastoid segment of the facial nerve

  9. [Anatomy of the skull base and the cranial nerves in slice imaging].

    Science.gov (United States)

    Bink, A; Berkefeld, J; Zanella, F

    2009-07-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are suitable methods for examination of the skull base. Whereas CT is used to evaluate mainly bone destruction e.g. for planning surgical therapy, MRI is used to show pathologies in the soft tissue and bone invasion. High resolution and thin slice thickness are indispensible for both modalities of skull base imaging. Detailed anatomical knowledge is necessary even for correct planning of the examination procedures. This knowledge is a requirement to be able to recognize and interpret pathologies. MRI is the method of choice for examining the cranial nerves. The total path of a cranial nerve can be visualized by choosing different sequences taking into account the tissue surrounding this cranial nerve. This article summarizes examination methods of the skull base in CT and MRI, gives a detailed description of the anatomy and illustrates it with image examples.

  10. Anatomy of the skull base and the cranial nerves in slice imaging

    International Nuclear Information System (INIS)

    Bink, A.; Berkefeld, J.; Zanella, F.

    2009-01-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are suitable methods for examination of the skull base. Whereas CT is used to evaluate mainly bone destruction e.g. for planning surgical therapy, MRI is used to show pathologies in the soft tissue and bone invasion. High resolution and thin slice thickness are indispensible for both modalities of skull base imaging. Detailed anatomical knowledge is necessary even for correct planning of the examination procedures. This knowledge is a requirement to be able to recognize and interpret pathologies. MRI is the method of choice for examining the cranial nerves. The total path of a cranial nerve can be visualized by choosing different sequences taking into account the tissue surrounding this cranial nerve. This article summarizes examination methods of the skull base in CT and MRI, gives a detailed description of the anatomy and illustrates it with image examples. (orig.) [de

  11. Reactive oxygen species in the paraventricular nucleus of the hypothalamus alter sympathetic activity during metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    JOSIANE CAMPOS CRUZ

    2015-12-01

    Full Text Available The paraventricular nucleus of the hypothalamus (PVN contains heterogeneous populations of neurons involved in autonomic and neuroendocrine regulation. The PVN plays an important role in the sympathoexcitatory response to increasing circulating levels of angiotensin II (Ang-II, which activates AT1 receptors in the circumventricular organs (OCVs, mainly in the subfornical organ (SFO. Circulating Ang-II induces a de novo synthesis of Ang-II in SFO neurons projecting to pre-autonomic PVN neurons. Activation of AT1 receptors induces intracellular increases in reactive oxygen species (ROS, leading to increases in sympathetic nerve activity (SNA. Chronic sympathetic nerve activation promotes a series of metabolic disorders that characterizes the metabolic syndrome (MetS: dyslipidemia, hyperinsulinemia, glucose intolerance, hyperleptinemia and elevated plasma hormone levels, such as noradrenaline, glucocorticoids, leptin, insulin and Ang-II. This review will discuss the contribution of our laboratory and others regarding the sympathoexcitation caused by peripheral Ang-II-induced reactive oxygen species along the subfornical organ and paraventricular nucleus of the hypothalamus. We hypothesize that this mechanism could be involved in metabolic disorders underlying MetS.

  12. Effects of the α-adrenoceptor antagonists phentolamine, phenoxybenzamine, and Idazoxan on sympathetic blood flow control in the periodontal ligament of the cat

    International Nuclear Information System (INIS)

    Edwall, B.; Gazelius, B.

    1988-01-01

    Blood flow changes in the periodontal ligament (PDL) were measured indirectly by monitoring the local clearance of 125 I - during electric sympathetic nerve stimulation or close intra-arterial infusions of either noradrenaline (NA) or adrenaline (ADR) before and after administration of phentolamine (PA), phenoxybenzamine (PBZ) or Idazoxan (RX). At the doses used in the present study, PA was the only antagonist that significantly reduced the blood flow decrease seen on activation of sympathetic fibers, although PBZ also reduced this response. Idazoxan, however, did not induce the consistent effect on blood flow decreases seen on sympathetic activation. All three α-adrenoceptor antagonists almost abolished the effects of exogenously administered NA and ADR. The results suggest the presence of functional post-junctional adrenoceptors of both the α 1 and α 2 subtypes in the sympathetic regulation of the blood flow in the PDL of the cat. A component of the response elicited by electrical sympathetic stimulation appeared to be resistant to α-adrenoceptor blockade. Administration of guanethidine (which inhibits further release of NA and neuropeptide Y) after PA abolished this residual sympathetic response

  13. High specific radioactivity (1R,2S)-4-[18F]fluorometaraminol: a PET radiotracer for mapping sympathetic nerves of the heart

    International Nuclear Information System (INIS)

    Langer, Oliver; Valette, Heric; Dolle, Frederic; Halldin, Christer; Loc'h, Christian; Fuseau, Chantal; Coulon, Christine; Ottaviani, Michele; Bottlaender, Michel; Maziere, Bernard; Crouzel, Christian

    2000-01-01

    The radiolabeled catecholamine analogue (1R,2S)-6-[ 18 F]fluorometaraminol (6-[ 18 F]FMR) is a substrate for the neuronal norepinephrine transporter. It has been used as a positron emission tomography (PET) ligand to map sympathetic nerves in dog heart. 6-[ 18 F]FMR could be only synthesized with low specific radioactivity, which precluded its use in human subjects. We have recently prepared (1R,2S)-4-[ 18 F]fluorometaraminol (4-[ 18 F]FMR), a new fluoro-analogue of metaraminol, with high specific radioactivity (56-106 GBq/μmol). In the present study, we demonstrate in rats that 4-[ 18 F]FMR possesses similar affinity toward myocardial norepinephrine transport mechanisms as 6-[ 18 F]FMR. When compared with control animals, an 80% and 76% reduction in myocardial uptake was observed in animals pretreated with desipramine (an inhibitor of the neuronal norepinephrine transporter) and with reserpine (a blocker of the vesicular storage of monoamines), respectively. The entire radioactivity in rat myocardium represented unmetabolized parent tracer as determined by high performance liquid chromatography analysis of tissue extracts. In dogs, myocardial kinetics of 4-[ 18 F]FMR were assessed using PET. A rapid and high uptake was observed, followed by prolonged cardiac retention. A heart-to-lung ratio of 15 was reached 10 min after injection of the radiotracer. Pretreatment with desipramine reduced the heart half-life of 4-[ 18 F]FMR by 90% compared with control. Moreover, an infusion of tyramine caused a rapid decline of radioactivity in the heart. This demonstrates that 4-[ 18 F]FMR specifically visualizes sympathetic neurons in dog heart. High specific radioactivity 4-[ 18 F]FMR is a promising alternative to 6-[ 18 F]FMR for myocardial neuronal mapping with PET in humans

  14. Normal and pathological findings for the facial nerve on magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Al-Noury, K., E-mail: Kalnoury@kau.edu.sa [Department of Otolaryngology, King Abdulaziz University, Jeddah (Saudi Arabia); Lotfy, A. [Radiology Department, King Abdulaziz University Hospital and International Medical Centre, Jeddah (Saudi Arabia)

    2011-08-15

    Aim: To demonstrate the enhanced radiological anatomy and common pathological conditions of the facial nerve by using magnetic resonance imaging (MRI). Materials and methods: A retrospective review of the MRI findings of the facial nerve of 146 patients who visited a tertiary academic referral center was conducted. Results: The radiological anatomy of the facial nerve was well illustrated using MRI, as were most of the common pathological conditions of the facial nerve. Conclusions: Enhancement of the facial nerve in MRI should be correlated with the clinical data. Normal individuals can show enhancement of the tympanic or vertical segments of the facial nerve. Enhancement of the labyrinthine portion of the nerve is almost diagnostic of Bell's palsy. No specific enhancement patterns were observed for tumours or for infections of the middle or external ear. A larger population study is required for the accurate assessment of facial nerve enhancement in multiple sclerosis patients.

  15. Clinical anatomy and imaging of the cranial nerves and skull base.

    Science.gov (United States)

    Jha, Ruchira M; Klein, Joshua P

    2012-09-01

    Evaluation of patients with cranial neuropathies requires an understanding of brainstem anatomy and nerve pathways. Advances in neuroimaging, particularly high spatial resolution magnetic resonance imaging (MRI), have enabled visualization of these tiny structures and their related pathology. This review provides an approach toward using imaging in the evaluation of cranial nerve (CN) and skull base anatomy and pathology. Because brainstem nuclei are inextricably linked to the information contained within CNs, they are briefly mentioned whenever relevant; however, a comprehensive discussion of brainstem syndromes is beyond the scope of this review. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. Electrical modulation of the sympathetic nervous system in order to augment cerebral blood flow : a protocol for an experimental study

    NARCIS (Netherlands)

    Ter Laan, Mark; van Dijk, J. Marc C.; Staal, Michiel J.; Elting, Jan-Willem J.

    2011-01-01

    Introduction: Cerebral blood flow (CBF) is regulated by several mechanisms. Neurogenic control has been a matter of debate, even though several publications reported the effects of changes in sympathetic tone on CBF. Transcutaneous electrical nerve stimulation and spinal-cord stimulation have been

  17. Optimising the image of the intradural nerve root: the value of MR radiculography

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, P.A.M. [Department of Diagnostic Radiology, University Hospital Maastricht (Netherlands); Wilmink, J.T. [Department of Diagnostic Radiology, University Hospital Maastricht (Netherlands)

    1996-10-01

    We evaluated the additional value of MR radiculography for increasing the sensitivity and specificity of MRI with regard to nerve root compression in patients with sciatica. The single slices of a heavily T 2-weighted oblique coronal image set were reformatted with a maximum intensity projection protocol. This image resembles a classical contrast radiculogram and shows the intradural nerve root and its sleeve. In 43 patients studied with a standard MRI examination there was a need for further assessment of nerve root compression in 19 (44 %). In 13 (68 %) of these, MR radiculography made a definite verdict possible. (orig.). With 4 figs., 2 tabs.

  18. Optimising the image of the intradural nerve root: the value of MR radiculography

    International Nuclear Information System (INIS)

    Hofman, P.A.M.; Wilmink, J.T.

    1996-01-01

    We evaluated the additional value of MR radiculography for increasing the sensitivity and specificity of MRI with regard to nerve root compression in patients with sciatica. The single slices of a heavily T 2-weighted oblique coronal image set were reformatted with a maximum intensity projection protocol. This image resembles a classical contrast radiculogram and shows the intradural nerve root and its sleeve. In 43 patients studied with a standard MRI examination there was a need for further assessment of nerve root compression in 19 (44 %). In 13 (68 %) of these, MR radiculography made a definite verdict possible. (orig.). With 4 figs., 2 tabs

  19. A new function for ATP: activating cardiac sympathetic afferents during myocardial ischemia.

    Science.gov (United States)

    Fu, Liang-Wu; Longhurst, John C

    2010-12-01

    Myocardial ischemia activates cardiac sympathetic afferents leading to chest pain and reflex cardiovascular responses. Brief myocardial ischemia leads to ATP release in the interstitial space. Furthermore, exogenous ATP and α,β-methylene ATP (α,β-meATP), a P2X receptor agonist, stimulate cutaneous group III and IV sensory nerve fibers. The present study tested the hypothesis that endogenous ATP excites cardiac afferents during ischemia through activation of P2 receptors. Nerve activity of single unit cardiac sympathetic afferents was recorded from the left sympathetic chain or rami communicates (T(2)-T(5)) in anesthetized cats. Single fields of 45 afferents (conduction velocities = 0.25-4.92 m/s) were identified in the left ventricle with a stimulating electrode. Five minutes of myocardial ischemia stimulated 39 of 45 cardiac afferents (8 Aδ, 37 C fibers). Epicardial application of ATP (1-4 μmol) stimulated six ischemically sensitive cardiac afferents in a dose-dependent manner. Additionally, epicardial ATP (2 μmol), ADP (2 μmol), a P2Y agonist, and α,β-meATP (0.5 μmol) significantly activated eight other ischemically sensitive afferents. Third, pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid, a P2 receptor antagonist, abolished the responses of six afferents to epicardial ATP (2 μmol) and attenuated the ischemia-related increase in activity of seven other afferents by 37%. In the absence of P2 receptor blockade, cardiac afferents responded consistently to repeated application of ATP (n = 6) and to recurrent myocardial ischemia (n = 6). Finally, six ischemia-insensitive cardiac spinal afferents did not respond to epicardial ATP (2-4 μmol), although these afferents did respond to epicardial bradykinin. Taken together, these data indicate that, during ischemia, endogenously released ATP activates ischemia-sensitive, but not ischemia-insensitive, cardiac spinal afferents through stimulation of P2 receptors likely located on the cardiac sensory

  20. Altered differential control of sympathetic outflow following sedentary conditions: Role of subregional neuroplasticity in the RVLM

    Directory of Open Access Journals (Sweden)

    Madhan Subramanian

    2016-07-01

    Full Text Available Despite the classically held belief of an all-or-none activation of the sympathetic nervous system, differential responses in sympathetic nerve activity (SNA can occur acutely at varying magnitudes and in opposing directions. Sympathetic nerves also appear to contribute differentially to various disease states including hypertension and heart failure. Previously we have reported that sedentary conditions enhanced responses of splanchnic SNA (SSNA but not lumbar SNA (LSNA to activation of the rostral ventrolateral medulla (RVLM in rats. Bulbospinal RVLM neurons from sedentary rats also exhibit increased dendritic branching in rostral regions of the RVLM. We hypothesized that regionally specific structural neuroplasticity would manifest as enhanced SSNA but not LSNA following activation of the rostral RVLM. To test this hypothesis, groups of physically active (10-12 weeks on running wheels or sedentary, male Sprague-Dawley rats were instrumented to record mean arterial pressure, LSNA and SSNA under Inactin anesthesia and during microinjections of glutamate (30 nl, 10 mM into multiple sites within the RVLM. Sedentary conditions enhanced SSNA but not LSNA responses and SSNA responses were enhanced at more central and rostral sites. Results suggest that enhanced SSNA responses in rostral RVLM coincide with enhanced dendritic branching in rostral RVLM observed previously. Identifying structural and functional neuroplasticity in specific populations of RVLM neurons may help identify new treatments for cardiovascular diseases, known to be more prevalent in sedentary individuals.

  1. Effects and Mechanisms of Radiofrequency Ablation of Renal Sympathetic Nerve on Anti-Hypertension in Canine

    Directory of Open Access Journals (Sweden)

    Wei Chen

    Full Text Available Abstract Background: Radiofrequency ablation of renal sympathetic nerve (RDN shows effective BP reduction in hypertensive patients while the specific mechanisms remain unclear. Objective: We hypothesized that abnormal levels of norepinephrine (NE and changes in NE-related enzymes and angiotensinconverting enzyme 2 (ACE2, angiotensin (Ang-(1-7 and Mas receptor mediate the anti-hypertensive effects of RDN. Methods: Mean values of systolic blood pressure (SBP, diastolic blood pressure (DBP and mean arterial pressure (MAP were assessed at baseline and follow-up. Plasma and renal norepinephrine (NE concentrations were determined using highperformance liquid chromatography with electrochemical detection, and levels of NE-related enzyme and ACE2-Ang(1-7- Mas were measured using real time PCR, Western blot and immunohistochemistry or Elisa in a hypertensive canine model fed with high-fat diet and treated with RDN. The parameters were also determined in a sham group treated with renal arteriography and a control group fed with normal diet. Results: RDN decreased SBP, DBP, MAP, plasma and renal NE. Compared with the sham group, renal tyrosine hydroxylase (TH expression was lower and renalase expression was higher in the RDN group. Compared with the control group, renal TH and catechol-o-methyl transferase (COMT were higher and renalase was lower in the sham group. Moreover, renal ACE2, Ang-(1-7 and Mas levels of the RDN group were higher than those of the sham group, which were lower than those of the control group. Conclusion: RDN shows anti-hypertensive effect with reduced NE and activation of ACE2-Ang(1-7-Mas, indicating that it may contribute to the anti-hypertensive effect of RDN.

  2. High-Resolution Isotropic Three-Dimensional MR Imaging of the Extraforaminal Segments of the Cranial Nerves.

    Science.gov (United States)

    Wen, Jessica; Desai, Naman S; Jeffery, Dean; Aygun, Nafi; Blitz, Ari

    2018-02-01

    High-resolution isotropic 3-dimensional (D) MR imaging with and without contrast is now routinely used for imaging evaluation of cranial nerve anatomy and pathologic conditions. The anatomic details of the extraforaminal segments are well-visualized on these techniques. A wide range of pathologic entities may cause enhancement or displacement of the nerve, which is now visible to an extent not available on standard 2D imaging. This article highlights the anatomy of extraforaminal segments of the cranial nerves and uses select cases to illustrate the utility and power of these sequences, with a focus on constructive interference in steady-state. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Quantitative evaluation of normal lumbosacral plexus nerve by using diffusion tensor imaging

    International Nuclear Information System (INIS)

    Shi Yin; Wang Chuanbing; Liu Wei; Zong Min; Sa Rina; Shi Haibin; Wang Dehang

    2014-01-01

    Objective: To observe the lumbosacral plexus nerves by diffusion tensor tractography (DTT) and quantitatively evaluate them by using diffusion tensor imaging (DTI) in healthy volunteers. Methods: A total of 60 healthy volunteers (30 males and 30 females) underwent DTI scanning. Mean FA values of the lumbosacral plexus nerves (both sides of lumbar roots L3 to S1, proximal and distal to the lumbar foraminal zone) were quantified. Differences among various segments of lumbar nerve roots were compared with ANOVA test and SNK test. Differences between two sides of the lumbar nerve roots at the same lumbar segment were compared with paired-samples t test. Differences between the proximal and the distal nerve to the the lumbar foraminal zone at the same lumbar segment were compared with paired-samples t test. The lumbosacral plexus nerve was visualized with tractography. Results: (1) The lumbosacral plexus nerve was clearly visualized with tractography. (2) Mean FA values of the lumbar nerve roots L3 to S1 were as followings: proximal to the left lumbar foraminal zone 0.202 ± 0.021, 0.201 ± 0.026, 0.201 ± 0.027, 0.191 ±0.016, distal to the left lumbar foraminal zone 0.222 ± 0.034, 0.250 ± 0.028, 0.203 ± 0.026, 0.183 ± 0.020, proximal to the right lumbar foraminal zone 0.200 ± 0.023, 0.202 ± 0.023, 0.205 ± 0.027, 0.191 ± 0.017, distal to the right lumbar foraminal zone 0.225 ± 0.032, 0.247 ± 0.027, 0.205 ± 0.033, 0.183 ± 0.021. Mean FA values were significantly different between the proximal nerve to the distal nerve in lumbar nerve roots L3, L4, S1 (t=-9.114-2.366, P<0.05), but not significantly different in L5 (P>0.05). Differences were not found between the right and left side nerves at the same lumbar segment (P>0.05). (3) The whole length of the lumbar roots nerve L3 to S1 can be visualized clearly by using DTT. Conclusions: Diffusion tensor imaging and tractography can show and provide quantitative information of human lumbosacral plexus nerves. DTI

  4. Sympathetic stimulation alters left ventricular relaxation and chamber size.

    Science.gov (United States)

    Burwash, I G; Morgan, D E; Koilpillai, C J; Blackmore, G L; Johnstone, D E; Armour, J A

    1993-01-01

    Alterations in left ventricular (LV) contractility, relaxation, and chamber dimensions induced by efferent sympathetic nerve stimulation were investigated in nine anesthetized open-chest dogs in sinus rhythm. Supramaximal stimulation of acutely decentralized left stellate ganglia augmented heart rate, LV systolic pressure, and rate of LV pressure rise (maximum +dP/dt, 1,809 +/- 191 to 6,304 +/- 725 mmHg/s) and fall (maximum -dP/dt, -2,392 +/- 230 to -4,458 +/- 482 mmHg/s). It also reduced the time constant of isovolumic relaxation, tau (36.5 +/- 4.8 to 14.9 +/- 1.1 ms). Simultaneous two-dimensional echocardiography recorded reductions in end-diastolic and end-systolic LV cross-sectional chamber areas (23 and 31%, respectively), an increase in area ejection fraction (32%), and increases in end-diastolic and end-systolic wall thicknesses (14 and 13%, respectively). End-systolic and end-diastolic wall stresses were unchanged by stellate ganglion stimulation (98 +/- 12 to 95 +/- 9 dyn x 10(3)/cm2; 6.4 +/- 2.4 to 2.4 +/- 0.3 dyn x 10(3)/cm2, respectively). Atrial pacing to similar heart rates did not alter monitored indexes of contractility. Dobutamine and isoproterenol induced changes similar to those resulting from sympathetic neuronal stimulation. These data indicate that when the efferent sympathetic nervous system increases left ventricular contractility and relaxation, concomitant reductions in systolic and diastolic dimensions of that chamber occur that are associated with increasing wall thickness such that LV wall stress changes are minimized.

  5. Diffusion-weighted magnetic resonance imaging of symptomatic nerve root of patients with lumbar disk herniation

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Yawara; Ohtori, Seiji; Yamashita, Masaomi; Yamauchi, Kazuyo; Suzuki, Munetaka; Orita, Sumihisa; Kamoda, Hiroto; Arai, Gen; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Ochiai, Nobuyasu; Kishida, Shunji; Inoue, Gen; Takahashi, Kazuhisa [Chiba University, Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba (Japan); Masuda, Yoshitada; Ochi, Shigehiro; Kikawa, Takashi [Chiba University Hospital, Department of Radiology, Chiba (Japan); Toyone, Tomoaki [Teikyo University Chiba Medical Center, Department of Orthopaedic Surgery, Chiba (Japan); Takaso, Masashi [Kitasato University, Department of Orthopaedic Surgery, School of Medicine, Sagamihara City, Kanagawa (Japan); Aoki, Yasuchika [Chiba Rosai Hospital, Department of Orthopedic Surgery, Ichihara, Chiba (Japan)

    2011-09-15

    Diffusion-weighted imaging (DWI) can provide valuable structural information that may be useful for evaluating pathological changes of the lumbar nerve root. Diffusion-weighted magnetic resonance (MR) neurography has recently been introduced as an alternative way to visualize nerves, but to date, quantitative DWI and MR neurography have not been applied to evaluate the pathology of lumbar nerve roots. Our purpose was to visualize lumbar nerve roots and to analyze their morphology by MR neurography, and to measure the apparent diffusion coefficient (ADC) of lumbar nerve roots compressed by herniated disks using 1.5-T MR imaging. Ten consecutive patients (median age, 48.0 and range, 20-72 years) with monoradicular symptoms caused by a lumbar herniated disk and 14 healthy volunteers were studied. Regions of interests were placed on the lumbar roots at dorsal root ganglia (DRG) and distal spinal nerves on DWI to quantify mean ADC values. The spinal nerve roots were also visualized by MR neurography. In the patients, mean ADC values were significantly greater in the compressed DRG and distal spinal nerves than in intact nerves. MR neurography also showed abnormalities such as nerve swelling at and below the compression in the symptomatic nerve root. Increased ADC values were considered to be because of edema and Wallerian degeneration of compressed nerve roots. DWI is a potential tool for analysis of the pathophysiology of lumbar nerve roots compressed by herniated disks. (orig.)

  6. Diffusion-weighted magnetic resonance imaging of symptomatic nerve root of patients with lumbar disk herniation

    International Nuclear Information System (INIS)

    Eguchi, Yawara; Ohtori, Seiji; Yamashita, Masaomi; Yamauchi, Kazuyo; Suzuki, Munetaka; Orita, Sumihisa; Kamoda, Hiroto; Arai, Gen; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Ochiai, Nobuyasu; Kishida, Shunji; Inoue, Gen; Takahashi, Kazuhisa; Masuda, Yoshitada; Ochi, Shigehiro; Kikawa, Takashi; Toyone, Tomoaki; Takaso, Masashi; Aoki, Yasuchika

    2011-01-01

    Diffusion-weighted imaging (DWI) can provide valuable structural information that may be useful for evaluating pathological changes of the lumbar nerve root. Diffusion-weighted magnetic resonance (MR) neurography has recently been introduced as an alternative way to visualize nerves, but to date, quantitative DWI and MR neurography have not been applied to evaluate the pathology of lumbar nerve roots. Our purpose was to visualize lumbar nerve roots and to analyze their morphology by MR neurography, and to measure the apparent diffusion coefficient (ADC) of lumbar nerve roots compressed by herniated disks using 1.5-T MR imaging. Ten consecutive patients (median age, 48.0 and range, 20-72 years) with monoradicular symptoms caused by a lumbar herniated disk and 14 healthy volunteers were studied. Regions of interests were placed on the lumbar roots at dorsal root ganglia (DRG) and distal spinal nerves on DWI to quantify mean ADC values. The spinal nerve roots were also visualized by MR neurography. In the patients, mean ADC values were significantly greater in the compressed DRG and distal spinal nerves than in intact nerves. MR neurography also showed abnormalities such as nerve swelling at and below the compression in the symptomatic nerve root. Increased ADC values were considered to be because of edema and Wallerian degeneration of compressed nerve roots. DWI is a potential tool for analysis of the pathophysiology of lumbar nerve roots compressed by herniated disks. (orig.)

  7. Three-dimensional imaging of the optic nerve using magnetic resonance angiography. Application to anterior communicating artery aneurysm and craniopharingioma

    International Nuclear Information System (INIS)

    Okuyama, Tohru; Fukuyama, Atsushi; Fukuyama, Koichi; Ikeno, Kunihiro; Araki, Hiroyuki; Okada, Kinya; Sohma, Noriko

    2005-01-01

    The purpose of this investigation was to analyze three-dimensional images of the optic nerve obtained by magnetic resonance angiography (MRA) in cases of anterior communicating artery aneurysm and craniopharingioma. Four ruptured anterior communicating artery aneurysms, five non-ruptured anterior communicating artery aneurysms and two craniopharingiomas were examined. The images were taken using MR/i Hispeed Plus 1.5 T Infinity version, and analyzed by Advantage Work station AW4.1. The routine MR imaging parameters are shown in Table. The imaging time was about 10 minutes. Analysis was made by reformation of images parallel to the optic nerve obtained from the original MRA images. The optic nerve and brain tumor were traced with paintbrush from one sheet to another of the reformed images after subtraction of the blood vessels around the anterior communicating artery in these reformed images, and then three-dimensional images were constructed. Three-dimensional images of the blood vessels were reconstructed from MIP (maximum intensity projection) images using the threshold method. The optic nerve and anterior communicating arterial aneurysm or brain tumor were both observed in the overlapped 3D-SSD (shaded surface display) images. The analysis time was about 15 minutes. Three-dimensional images of the optic nerve and anterior communicating artery aneurysm or brain tumor were able to be made in all cases. As a preoperative investigation for anterior communicating artery aneurysm or suprasellar brain tumor, we considered that three-dimensional imaging of the optic nerve is useful in the operative approach because the optic nerve acts as a merkmal for the anterior communicating aneurysm or brain tumor. (author)

  8. ANATOMICAL STUDY OF CRANIAL NERVE EMERGENCE AND SKULL FORAMINA IN THE HORSE USING MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY.

    Science.gov (United States)

    Gonçalves, Rita; Malalana, Fernando; McConnell, James Fraser; Maddox, Thomas

    2015-01-01

    For accurate interpretation of magnetic resonance (MR) images of the equine brain, knowledge of the normal cross-sectional anatomy of the brain and associated structures (such as the cranial nerves) is essential. The purpose of this prospective cadaver study was to describe and compare MRI and computed tomography (CT) anatomy of cranial nerves' origins and associated skull foramina in a sample of five horses. All horses were presented for euthanasia for reasons unrelated to the head. Heads were collected posteuthanasia and T2-weighted MR images were obtained in the transverse, sagittal, and dorsal planes. Thin-slice MR sequences were also acquired using transverse 3D-CISS sequences that allowed mutliplanar reformatting. Transverse thin-slice CT images were acquired and multiplanar reformatting was used to create comparative images. Magnetic resonance imaging consistently allowed visualization of cranial nerves II, V, VII, VIII, and XII in all horses. The cranial nerves III, IV, and VI were identifiable as a group despite difficulties in identification of individual nerves. The group of cranial nerves IX, X, and XI were identified in 4/5 horses although the region where they exited the skull was identified in all cases. The course of nerves II and V could be followed on several slices and the main divisions of cranial nerve V could be distinguished in all cases. In conclusion, CT allowed clear visualization of the skull foramina and occasionally the nerves themselves, facilitating identification of the nerves for comparison with MRI images. © 2015 American College of Veterinary Radiology.

  9. Magnetic resonance imaging evaluation of acute crush injury of rabbit sciatic nerve: correlation with histology

    International Nuclear Information System (INIS)

    Li, X.; Shen, J.; Chen, J.; Wang, X.; Liu, Q.; Liang, B.

    2008-01-01

    To investigate the relation between the quantitative assessment of magnetic resonance imaging (MRI) features and the correlation with histology and functional recovery by using the rabbit sciatic nerve crush model. In New Zealand, 32 rabbits were randomly divided into 2 groups (group A and B); all rabbits underwent crushing injury of their left sciatic nerve. In group A (n = 16), the sciatic nerves were crushed by using microvessel clamps with a strength of 3.61 kg. In group B (n = 16), the sciatic nerves were crushed with a strength of 10.50 kg. Right sciatic nerves were served as controls. Serial MRI of both hind limbs in each rabbit was performed before and at the time point of 1, 2, 4, and 8 weeks after crushed injury. The MRI protocol included T1-weighted spin-echo (T1WI), 3 dimension turbo spin-echo T2-weighted (3DT2WI), T2-weighted turbo spin-echo images with spectral presaturation with inversion recovery (T2WI/SPIR), balanced fast-field echo (B-FFE) and short-time inversion recovery (STIR) sequences. The coronal image of the sciatic nerve was obtained. The nerve and muscle signal ratio (SIR) on each sequence was measured. The function recovery was observed and pathological examination was performed at each time point. A signal intensity increase of the distal segment of crushed sciatic nerves was found on 3DT2WI, T2WI/SP1R, B-FFE, and STIR, but not on T,WI images. Of 32 crushed nerves, 30 nerves showed high signal intensity. The correct diagnostic rate was 93.75% with false negative-positive of 6.25%. The SIR of the crushed sciatic nerve at distal portion was higher than those of the control nerves; there was a statistically significant difference (P 0.05). The SIR between group A and group B was not found statistically significantly different (P > 0.05). The SIR of crushed nerves at distal portion increased at one week after the crush injury, subsequently further increased, and reached a maximum at 2 weeks. The pathological examination revealed myelin

  10. The role of ultrasound imaging in the evaluation of peripheral nerve in systemic sclerosis (scleroderma)

    International Nuclear Information System (INIS)

    Tagliafico, Alberto; Panico, Nicoletta; Resmini, Eugenia; Derchi, Lorenzo E.; Ghio, Massimo; Martinoli, Carlo

    2011-01-01

    Background: Patients affected by scleroderma may complain of sensory disturbances especially in the hands. Purpose: To study the imaging features of upper limb nerves in patients affected by scleroderma (SSc). Materials and method: Twenty-five patients affected only by SSc were prospectively evaluated with high-resolution US and magnetic resonance (MRI) or computer tomography (CT) when necessary (2 patients). Median and ulnar nerves were evaluated bilaterally. Nerve conduction studies were performed in the symptomatic patients (n = 10). Results of imaging studies were correlated with disease duration, autoimmunity and immunosuppression. Nerves of SSc patients were compared with a control group of 90 patients matched for age and body mass index. Results: The prevalence of sensory disturbances revealed by clinical examination was 40%. In symptomatic SSc patients (n = 10) US evaluation revealed nerve abnormalities in 70% of cases (n = 7/10). n = 2 had a carpal tunnel syndrome. n = 5 had cubital tunnel syndrome. In two of them CT and MR were necessary to identify the compressed nerve at the level of the elbow due to the presence of calcifications. There was no association between the presence of an entrapment neuropathy and disease duration, autoantibodies and immunosuppression. Conclusion: Ultrasound, CT and MR may detect nerve abnormalities in 70% of SSc patients complaining of neurologic disturbances in the hands. The results of imaging studies support the hypothesis of a vascular dependent neuropathy in SSc.

  11. The role of ultrasound imaging in the evaluation of peripheral nerve in systemic sclerosis (scleroderma)

    Energy Technology Data Exchange (ETDEWEB)

    Tagliafico, Alberto, E-mail: atagliafico@sirm.org [Department of Radiology, University of Genova, Genova (Italy); Panico, Nicoletta [Division of Immunology, Department of Internal Medicine, University of Genoa, Genoa (Italy); Resmini, Eugenia [Department of Endocrinological and Medical Sciences (DiSEM), Center of Excellence for Biomedical Research, University of Genova, Genova (Italy); Derchi, Lorenzo E. [Department of Radiology, University of Genova, Genova (Italy); Ghio, Massimo [Division of Immunology, Department of Internal Medicine, University of Genoa, Genoa (Italy); Martinoli, Carlo [Department of Radiology, University of Genova, Genova (Italy)

    2011-03-15

    Background: Patients affected by scleroderma may complain of sensory disturbances especially in the hands. Purpose: To study the imaging features of upper limb nerves in patients affected by scleroderma (SSc). Materials and method: Twenty-five patients affected only by SSc were prospectively evaluated with high-resolution US and magnetic resonance (MRI) or computer tomography (CT) when necessary (2 patients). Median and ulnar nerves were evaluated bilaterally. Nerve conduction studies were performed in the symptomatic patients (n = 10). Results of imaging studies were correlated with disease duration, autoimmunity and immunosuppression. Nerves of SSc patients were compared with a control group of 90 patients matched for age and body mass index. Results: The prevalence of sensory disturbances revealed by clinical examination was 40%. In symptomatic SSc patients (n = 10) US evaluation revealed nerve abnormalities in 70% of cases (n = 7/10). n = 2 had a carpal tunnel syndrome. n = 5 had cubital tunnel syndrome. In two of them CT and MR were necessary to identify the compressed nerve at the level of the elbow due to the presence of calcifications. There was no association between the presence of an entrapment neuropathy and disease duration, autoantibodies and immunosuppression. Conclusion: Ultrasound, CT and MR may detect nerve abnormalities in 70% of SSc patients complaining of neurologic disturbances in the hands. The results of imaging studies support the hypothesis of a vascular dependent neuropathy in SSc.

  12. MRI-based diagnostic imaging of the intratemporal facial nerve

    International Nuclear Information System (INIS)

    Kress, B.; Baehren, W.

    2001-01-01

    Detailed imaging of the five sections of the full intratemporal course of the facial nerve can be achieved by MRI and using thin tomographic section techniques and surface coils. Contrast media are required for tomographic imaging of pathological processes. Established methods are available for diagnostic evaluation of cerebellopontine angle tumors and chronic Bell's palsy, as well as hemifacial spasms. A method still under discussion is MRI for diagnostic evaluation of Bell's palsy in the presence of fractures of the petrous bone, when blood volumes in the petrous bone make evaluation even more difficult. MRI-based diagnostic evaluation of the idiopatic facial paralysis currently is subject to change. Its usual application cannot be recommended for routine evaluation at present. However, a quantitative analysis of contrast medium uptake of the nerve may be an approach to improve the prognostic value of MRI in acute phases of Bell's palsy. (orig./CB) [de

  13. High specific radioactivity (1R,2S)-4-[{sup 18}F]fluorometaraminol: a PET radiotracer for mapping sympathetic nerves of the heart

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Valette, Heric; Dolle, Frederic E-mail: dolle@dsvidf.cea.fr; Halldin, Christer; Loc' h, Christian; Fuseau, Chantal; Coulon, Christine; Ottaviani, Michele; Bottlaender, Michel; Maziere, Bernard; Crouzel, Christian

    2000-04-01

    The radiolabeled catecholamine analogue (1R,2S)-6-[{sup 18}F]fluorometaraminol (6-[{sup 18}F]FMR) is a substrate for the neuronal norepinephrine transporter. It has been used as a positron emission tomography (PET) ligand to map sympathetic nerves in dog heart. 6-[{sup 18}F]FMR could be only synthesized with low specific radioactivity, which precluded its use in human subjects. We have recently prepared (1R,2S)-4-[{sup 18}F]fluorometaraminol (4-[{sup 18}F]FMR), a new fluoro-analogue of metaraminol, with high specific radioactivity (56-106 GBq/{mu}mol). In the present study, we demonstrate in rats that 4-[{sup 18}F]FMR possesses similar affinity toward myocardial norepinephrine transport mechanisms as 6-[{sup 18}F]FMR. When compared with control animals, an 80% and 76% reduction in myocardial uptake was observed in animals pretreated with desipramine (an inhibitor of the neuronal norepinephrine transporter) and with reserpine (a blocker of the vesicular storage of monoamines), respectively. The entire radioactivity in rat myocardium represented unmetabolized parent tracer as determined by high performance liquid chromatography analysis of tissue extracts. In dogs, myocardial kinetics of 4-[{sup 18}F]FMR were assessed using PET. A rapid and high uptake was observed, followed by prolonged cardiac retention. A heart-to-lung ratio of 15 was reached 10 min after injection of the radiotracer. Pretreatment with desipramine reduced the heart half-life of 4-[{sup 18}F]FMR by 90% compared with control. Moreover, an infusion of tyramine caused a rapid decline of radioactivity in the heart. This demonstrates that 4-[{sup 18}F]FMR specifically visualizes sympathetic neurons in dog heart. High specific radioactivity 4-[{sup 18}F]FMR is a promising alternative to 6-[{sup 18}F]FMR for myocardial neuronal mapping with PET in humans.

  14. Imaging the ocular motor nerves.

    NARCIS (Netherlands)

    Ferreira, T.; Verbist, B.M.; Buchem, M. van; Osch, T. van; Webb, A.

    2010-01-01

    The ocular motor nerves (OMNs) comprise the oculomotor, trochlear and the abducens nerves. According to their course, they are divided into four or five anatomic segments: intra-axial, cisternal, cavernous and intra-orbital and, for the abducens nerve, an additional interdural segment. Magnetic

  15. Radial nerve dysfunction (image)

    Science.gov (United States)

    The radial nerve travels down the arm and supplies movement to the triceps muscle at the back of the upper arm. ... the wrist and hand. The usual causes of nerve dysfunction are direct trauma, prolonged pressure on the ...

  16. Role of magnetic resonance imaging in entrapment and compressive neuropathy - what, where, and how to see the peripheral nerves on the musculoskeletal magnetic resonance image: Part 2. Upper extremity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sungjun [Yonsei University, Department of Diagnostic Radiology, College of Medicine, Seoul (Korea); Hanyang University, Kuri Hospital, Department of Diagnostic Radiology, College of Medicine, Kuri City, Kyunggi-do (Korea); Choi, Jin-Young; Huh, Yong-Min; Song, Ho-Taek; Lee, Sung-Ah [Yonsei University, Department of Diagnostic Radiology, College of Medicine, Seoul (Korea); Kim, Seung Min [Yonsei University, Department of Neurology, College of Medicine, Seoul (Korea); Suh, Jin-Suck [Yonsei University, Department of Diagnostic Radiology, College of Medicine, Seoul (Korea); Yonsei University, Research Institute of Radiological Science, College of Medicine, Seoul (Korea)

    2007-02-15

    The diagnosis of nerve entrapment and compressive neuropathy has been traditionally based on the clinical and electrodiagnostic examinations. As a result of improvements in the magnetic resonance (MR) imaging modality, it plays not only a fundamental role in the detection of space-occupying lesions, but also a compensatory role in clinically and electrodiagnostically inconclusive cases. Although ultrasound has undergone further development in the past decades and shows high resolution capabilities, it has inherent limitations due to its operator dependency. We review the course of normal peripheral nerves, as well as various clinical demonstrations and pathological features of compressed and entrapped nerves in the upper extremities on MR imaging, according to the nerves involved. The common sites of nerve entrapment of the upper extremity are as follows: the brachial plexus of the thoracic outlet; axillary nerve of the quadrilateral space; radial nerve of the radial tunnel; ulnar nerve of the cubital tunnel and Guyon's canal; median nerve of the pronator syndrome, anterior interosseous nerve syndrome, and carpal tunnel syndrome. Although MR imaging can depict the peripheral nerves in the extremities effectively, radiologists should be familiar with nerve pathways, common sites of nerve compression, and common space-occupying lesions resulting in nerve compression in MR imaging. (orig.)

  17. Role of magnetic resonance imaging in entrapment and compressive neuropathy - what, where, and how to see the peripheral nerves on the musculoskeletal magnetic resonance image: Part 2. Upper extremity

    International Nuclear Information System (INIS)

    Kim, Sungjun; Choi, Jin-Young; Huh, Yong-Min; Song, Ho-Taek; Lee, Sung-Ah; Kim, Seung Min; Suh, Jin-Suck

    2007-01-01

    The diagnosis of nerve entrapment and compressive neuropathy has been traditionally based on the clinical and electrodiagnostic examinations. As a result of improvements in the magnetic resonance (MR) imaging modality, it plays not only a fundamental role in the detection of space-occupying lesions, but also a compensatory role in clinically and electrodiagnostically inconclusive cases. Although ultrasound has undergone further development in the past decades and shows high resolution capabilities, it has inherent limitations due to its operator dependency. We review the course of normal peripheral nerves, as well as various clinical demonstrations and pathological features of compressed and entrapped nerves in the upper extremities on MR imaging, according to the nerves involved. The common sites of nerve entrapment of the upper extremity are as follows: the brachial plexus of the thoracic outlet; axillary nerve of the quadrilateral space; radial nerve of the radial tunnel; ulnar nerve of the cubital tunnel and Guyon's canal; median nerve of the pronator syndrome, anterior interosseous nerve syndrome, and carpal tunnel syndrome. Although MR imaging can depict the peripheral nerves in the extremities effectively, radiologists should be familiar with nerve pathways, common sites of nerve compression, and common space-occupying lesions resulting in nerve compression in MR imaging. (orig.)

  18. Alternating myocardial sympathetic neural function of athlete's heart in professional cycle racers examined with iodine-123-MIBG myocardial scintigraphy

    International Nuclear Information System (INIS)

    Koyama, Keiko; Inoue, Tomio; Hasegawa, Akira; Oriuchi, Noboru; Okamoto, Eiichi; Tomaru, Yumi; Endo, Keigo

    2001-01-01

    Myocardial sympathetic neural function in professional athletes who had the long-term tremendous cardiac load has not been fully investigated by myocardial iodine-123-metaiodobenzylguanidine (MIBG) uptake in comparison with power spectral analysis (PSA) in electrocardiography. Eleven male professional cycle racers and age-matched 11 male healthy volunteers were enrolled in this study. The low frequency components in the power spectral density (LF), the high frequency components in the power spectral density (HF), the LF/HF ratio and mean R-R interval were derived from PSA and time-domain analysis of heart rate variability in electrocardiography. The mean heart-to-mediastinum uptake ratio (H/M ratio) of the MIBG uptake, in professional cycle racers was significantly lower than that in healthy volunteers (p<0.01) and HF power in professional cycle racers was significantly higher than that in healthy volunteers (p<0.05). In the group of professional cycle racers, the H/M ratio showed a significant correlation with the R-R interval, as indices of parasympathetic nerve activity (r=0.80, p<0.01), but not with the LF/HF ratio as an index of sympathetic nerve activity. These results may indicate that parasympathetic nerve activity has an effect on MIBG uptake in a cyclist's heart. (author)

  19. Dual-model automatic detection of nerve-fibres in corneal confocal microscopy images.

    Science.gov (United States)

    Dabbah, M A; Graham, J; Petropoulos, I; Tavakoli, M; Malik, R A

    2010-01-01

    Corneal Confocal Microscopy (CCM) imaging is a non-invasive surrogate of detecting, quantifying and monitoring diabetic peripheral neuropathy. This paper presents an automated method for detecting nerve-fibres from CCM images using a dual-model detection algorithm and compares the performance to well-established texture and feature detection methods. The algorithm comprises two separate models, one for the background and another for the foreground (nerve-fibres), which work interactively. Our evaluation shows significant improvement (p approximately 0) in both error rate and signal-to-noise ratio of this model over the competitor methods. The automatic method is also evaluated in comparison with manual ground truth analysis in assessing diabetic neuropathy on the basis of nerve-fibre length, and shows a strong correlation (r = 0.92). Both analyses significantly separate diabetic patients from control subjects (p approximately 0).

  20. CaMKII Regulates Synaptic NMDA Receptor Activity of Hypothalamic Presympathetic Neurons and Sympathetic Outflow in Hypertension.

    Science.gov (United States)

    Li, De-Pei; Zhou, Jing-Jing; Zhang, Jixiang; Pan, Hui-Lin

    2017-11-01

    NMDAR activity in the hypothalamic paraventricular nucleus (PVN) is increased and critically involved in heightened sympathetic vasomotor tone in hypertension. Calcium/calmodulin-dependent protein kinase II (CaMKII) binds to and modulates NMDAR activity. In this study, we determined the role of CaMKII in regulating NMDAR activity of PVN presympathetic neurons in male spontaneously hypertensive rats (SHRs). NMDAR-mediated EPSCs and puff NMDA-elicited currents were recorded in spinally projecting PVN neurons in SHRs and male Wistar-Kyoto (WKY) rats. The basal amplitude of evoked NMDAR-EPSCs and puff NMDA currents in retrogradely labeled PVN neurons were significantly higher in SHRs than in WKY rats. The CaMKII inhibitor autocamtide-2-related inhibitory peptide (AIP) normalized the increased amplitude of NMDAR-EPSCs and puff NMDA currents in labeled PVN neurons in SHRs but had no effect in WKY rats. Treatment with AIP also normalized the higher frequency of NMDAR-mediated miniature EPSCs of PVN neurons in SHRs. CaMKII-mediated phosphorylation level of GluN2B serine 1303 (S1303) in the PVN, but not in the hippocampus and frontal cortex, was significantly higher in SHRs than in WKY rats. Lowering blood pressure with celiac ganglionectomy in SHRs did not alter the increased level of phosphorylated GluN2B S1303 in the PVN. In addition, microinjection of AIP into the PVN significantly reduced arterial blood pressure and lumbar sympathetic nerve discharges in SHRs. Our findings suggest that CaMKII activity is increased in the PVN and contributes to potentiated presynaptic and postsynaptic NMDAR activity to elevate sympathetic vasomotor tone in hypertension. SIGNIFICANCE STATEMENT Heightened sympathetic vasomotor tone is a major contributor to the development of hypertension. Although glutamate NMDA receptor (NMDAR)-mediated excitatory drive in the hypothalamus plays a critical role in increased sympathetic output in hypertension, the molecular mechanism involved in

  1. Diffusion tensor imaging of the auditory nerve in patients with acquired single-sided deafness

    DEFF Research Database (Denmark)

    Vos, Sjoerd; Haakma, Wieke; Versnel, Huib

    2015-01-01

    following cochlear hair cell loss, and the amount of degeneration may considerably differ between the two ears, also in patients with bilateral deafness. A measure that reflects the nerve's condition would help to assess the best of both nerves and decide accordingly which ear should be implanted......A cochlear implant (CI) can restore hearing in patients with profound sensorineural hearing loss by direct electrical stimulation of the auditory nerve. Therefore, the viability of the auditory nerve is vitally important in successful hearing recovery. However, the nerve typically degenerates...... single-sided sensorineural hearing loss. A specialized acquisition protocol was designed for a 3 T MRI scanner to image the small nerve bundle. The nerve was reconstructed using fiber tractography and DTI metrics - which reflect the nerve's microstructural properties - were computed per tract. Comparing...

  2. Localization and neurochemical characteristics of the extrinsic sympathetic neurons projecting to the pylorus in the domestic pig.

    Science.gov (United States)

    Zalecki, Michal

    2012-01-01

    The pylorus, an important part of the digestive tract controlling the flow of chyme between the stomach and the duodenum, is widely innervated by intrinsic and extrinsic nerves. To determine the locations of postganglionic sympathetic perikarya that innervate the pylorus of the domestic pig, a retrograde tracing method with application of Fast Blue tracer was used. All positive neuronal cell bodies (ca. 1750) were found in the celiac-cranial mesenteric ganglion complex (CSMG), however, the coeliac poles of this complex provided the major input to the pylorus. Afterwards, the immunohistochemical staining procedure was applied to determine biologically active substances expressed in the FB-labeled perikarya. Approximately 77% of the FB-positive cell bodies contained tyrosine hydroxylase (TH), 87% dopamine β-hydroxylase (DβH), 40% neuropeptide Y (NPY), 12% somatostatin (SOM) and 7% galanin (GAL). The presence of all these substances in the ganglion tissue was confirmed by RT-PCR technique. Double immunocytochemistry revealed that all of the TH-positive perikarya contained DβH, about 40% NPY, 12% SOM and 8% GAL. Additionally, all above-cited immunohistochemical markers as well as VIP, PACAP, ChAT, LEU, MET, SP and nNOS were observed within nerve fibers associated with the FB-positive perikarya. Immunocytochemical labeling of the pyloric wall tissue disclosed that TH+, DβH+ and NPY+ nerve fibers innervated ganglia of the myenteric and submucosal plexuses, blood vessels, both muscular layers and the muscularis mucosae; nerve fibers immunoreactive to GAL mostly innervated both muscular layers, while SOM+ nerve fibers were observed within the myenteric plexus. Presented study revealed sources of origin and immunohistochemical characteristics of the sympathetic postganglionic perikarya innervating the porcine pylorus. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Sympathetic Nerves in Breast Cancer: Angiogenesis and Antiangiogenic Therapy

    Science.gov (United States)

    2013-02-01

    an enzyme found only outside nerve terminals (6). We showed that splenic NE and NMN were markedly elevated 3 days after DMI implantation relative to...daily ISO treatment (Figs. 3A; attached manuscript day x treatment interaction, p = 0.14). To further investigate potential ß-AR-induced effects on...It has high affinity for ß2-AR, but is unable to desensitize ß-AR, resulting in a long-term effectiveness that cannot be achieved with most ß-agonists

  4. In vivo assessment of peripheral nerve regeneration by diffusion tensor imaging.

    Science.gov (United States)

    Morisaki, Shinsuke; Kawai, Yuko; Umeda, Masahiro; Nishi, Mayumi; Oda, Ryo; Fujiwara, Hiroyoshi; Yamada, Kei; Higuchi, Toshihiro; Tanaka, Chuzo; Kawata, Mitsuhiro; Kubo, Toshikazu

    2011-03-01

    To evaluate the sensitivity of diffusion tensor imaging (DTI) in assessing peripheral nerve regeneration in vivo. We assessed the changes in the DTI parameters and histological analyses after nerve injury to examine degeneration and regeneration in the rat sciatic nerves. For magnetic resonance imaging (MRI), 16 rats were randomly divided into two groups: group P (permanently crushed; n = 7) and group T (temporally crushed; n = 9). Serial MRI of the right leg was performed before the operation, and then performed at the timepoints of 1, 2, 3, and 4 weeks after the crush injury. The changes in fractional anisotropy (FA), axial diffusivity (λ(∥)), and radial diffusivity (λ(⟂)) were quantified. For histological analyses, the number of axons and the myelinated axon areas were quantified. Decreased FA and increased λ(⟂) were observed in the degenerative phase, and increased FA and decreased λ(⟂) were observed in the regenerative phase. The changes in FA and λ(⟂) were strongly correlated with histological changes, including axonal and myelin regeneration. DTI parameters, especially λ(⟂) , can be good indicators for peripheral nerve regeneration and can be applied as noninvasive diagnostic tools for a variety of neurological diseases. Copyright © 2011 Wiley-Liss, Inc.

  5. In-vivo imaging of retinal nerve fiber layer vasculature: imaging – histology comparison

    Directory of Open Access Journals (Sweden)

    Libby Richard T

    2009-08-01

    Full Text Available Abstract Background Although it has been suggested that alterations of nerve fiber layer vasculature may be involved in the etiology of eye diseases, including glaucoma, it has not been possible to examine this vasculature in-vivo. This report describes a novel imaging method, fluorescence adaptive optics (FAO scanning laser ophthalmoscopy (SLO, that makes possible for the first time in-vivo imaging of this vasculature in the living macaque, comparing in-vivo and ex-vivo imaging of this vascular bed. Methods We injected sodium fluorescein intravenously in two macaque monkeys while imaging the retina with an FAO-SLO. An argon laser provided the 488 nm excitation source for fluorescence imaging. Reflectance images, obtained simultaneously with near infrared light, permitted precise surface registration of individual frames of the fluorescence imaging. In-vivo imaging was then compared to ex-vivo confocal microscopy of the same tissue. Results Superficial focus (innermost retina at all depths within the NFL revealed a vasculature with extremely long capillaries, thin walls, little variation in caliber and parallel-linked structure oriented parallel to the NFL axons, typical of the radial peripapillary capillaries (RPCs. However, at a deeper focus beneath the NFL, (toward outer retina the polygonal pattern typical of the ganglion cell layer (inner and outer retinal vasculature was seen. These distinguishing patterns were also seen on histological examination of the same retinas. Furthermore, the thickness of the RPC beds and the caliber of individual RPCs determined by imaging closely matched that measured in histological sections. Conclusion This robust method demonstrates in-vivo, high-resolution, confocal imaging of the vasculature through the full thickness of the NFL in the living macaque, in precise agreement with histology. FAO provides a new tool to examine possible primary or secondary role of the nerve fiber layer vasculature in retinal

  6. Sympathetic and parasympathetic regulation of rectal motility in rats.

    Science.gov (United States)

    Ridolfi, Timothy J; Tong, Wei-Dong; Takahashi, Toku; Kosinski, Lauren; Ludwig, Kirk A

    2009-11-01

    The colon and rectum are regulated by the autonomic nervous system (ANS). Abnormalities of the ANS are associated with diseases of the colon and rectum while its modulation is a putative mechanism for sacral nerve stimulation. The purpose of this study is to establish a rat model elucidating the role of the efferent ANS on rectal motility. Rectal motility following transection or stimulation of parasympathetic pelvic nerves (PN) or sympathetic hypogastric nerves (HGN) was measured with rectal strain gauge transducers and quantified as a motility index (MI). Colonic transit was measured 24 hours after transection by calculating the geometric center (GC) of distribution of (51)Cr Transection of PN and HGN decreased MI to 518 +/- 185 g*s (p < 0.05) and increased MI to 5,029 +/- 1,954 g*s (p < 0.05), respectively, compared to sham (975 +/- 243 g*s). Sectioning of PN and HGN decreased transit with GC = 4.9 +/- 0.2 (p < 0.05) and increased transit with GC = 8.1 +/- 0.7 (p < 0.02), respectively, compared to sham (GC = 5.8 +/- 0.3). Stimulation of PN and HGN increased MI to 831 +/- 157% (p < 0.01) and decreased MI to 251 +/- 24% (p < 0.05), respectively. Rectal motility is significantly altered by sectioning or stimulating either HGN or PN. This model may be useful in studying how sacral nerve stimulation exerts its effects and provide insight into the maladies of colonic motility.

  7. Bioelectronic block of paravertebral sympathetic nerves mitigates post-myocardial infarction ventricular arrhythmias.

    Science.gov (United States)

    Chui, Ray W; Buckley, Una; Rajendran, Pradeep S; Vrabec, Tina; Shivkumar, Kalyanam; Ardell, Jeffrey L

    2017-11-01

    Autonomic dysfunction contributes to induction of ventricular tachyarrhythmia (VT). To determine the efficacy of charge-balanced direct current (CBDC), applied to the T1-T2 segment of the paravertebral sympathetic chain, on VT inducibility post-myocardial infarction (MI). In a porcine model, CBDC was applied in acute animals (n = 7) to optimize stimulation parameters for sympathetic blockade and in chronic MI animals (n = 7) to evaluate the potential for VTs. Chronic MI was induced by microsphere embolization of the left anterior descending coronary artery. At termination, in anesthetized animals and following thoracotomy, an epicardial sock array was placed over both ventricles and a quadripolar carousel electrode positioned underlying the right T1-T2 paravertebral chain. In acute animals, the efficacy of CBDC carousel (CBDCC) block was assessed by evaluating cardiac function during T2 paravertebral ganglion stimulation with and without CBDCC. In chronic MI animals, VT inducibility was assessed by extrasystolic (S1-S2) stimulations at baseline and under >66% CBDCC blockade of T2-evoked sympathoexcitation. CBDCC demonstrated a current-dependent and reversible block without impacting basal cardiac function. VT was induced at baseline in all chronic MI animals. One animal died after baseline induction. Of the 6 remaining animals, only 1 was reinducible with simultaneous CBDCC application (P block of the T1-T2 paravertebral chain with CBDCC reduced VT in a chronic MI model. CBDCC prolonged VERP, without altering baseline cardiac function, resulting in improved electrical stability. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  8. Retrospective comparison of three-dimensional imaging sequences in the visualization of posterior fossa cranial nerves.

    Science.gov (United States)

    Ors, Suna; Inci, Ercan; Turkay, Rustu; Kokurcan, Atilla; Hocaoglu, Elif

    2017-12-01

    To compare efficancy of three-dimentional SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolutions) and CISS (constructive interference in steady state) sequences in the imaging of the cisternal segments of cranial nerves V-XII. Temporal MRI scans from 50 patients (F:M ratio, 27:23; mean age, 44.5±15.9 years) admitted to our hospital with vertigo, tinnitus, and hearing loss were retrospectively analyzed. All patients had both CISS and SPACE sequences. Quantitative analysis of SPACE and CISS sequences was performed by measuring the ventricle-to-parenchyma contrast-to-noise ratio (CNR). Qualitative analysis of differences in visualization capability, image quality, and severity of artifacts was also conducted. A score ranging 'no artefact' to 'severe artefacts and unreadable' was used for the assessment of artifacts and from 'not visualized' to 'completely visualized' for the assesment of image quality, respectively. The distribution of variables was controlled by the Kolmogorov-Smirnov test. Samples t-test and McNemar's test were used to determine statistical significance. Rates of visualization of posterior fossa cranial nerves in cases of complete visualization were as follows: nerve V (100% for both sequences), nerve VI (94% in SPACE, 86% in CISS sequences), nerves VII-VIII (100% for both sequences), IX-XI nerve complex (96%, 88%); nerve XII (58%, 46%) (p<0.05). SPACE sequences showed fewer artifacts than CISS sequences (p<0.002). Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Diabetic cardiac autonomic dysfunction. Parasympathetic versus sympathetic

    International Nuclear Information System (INIS)

    Uehara, Akihiko; Kurata, Chinori; Sugi, Toshihiko; Mikami, Tadashi; Shouda, Sakae

    1999-01-01

    Diabetic cardiac autonomic dysfunction often causes lethal arrhythmia and sudden cardiac death. 123 I-Metaiodobenzylguanidine (MIBG) can evaluate cardiac sympathetic dysfunction, and analysis of heart rate variability (HRV) can reflect cardiac parasympathetic activity. We examined whether cardiac parasympathetic dysfunction assessed by HRV may correlate with sympathetic dysfunction assessed by MIBG in diabetic patients. In 24-hour electrocardiography, we analyzed 4 HRV parameters: high-frequency power (HF), HF in the early morning (EMHF), rMSSD and pNN50. MIBG planar images and SPECT were obtained 15 minutes (early) and 150 minutes (late) after injection and the heart washout rate was calculated. The defect score in 9 left ventricular regions was scored on a 4 point scale (0=normal - 3=severe defect). In 20 selected diabetic patients without congestive heart failure, coronary artery disease and renal failure, parasympathetic HRV parameters had a negative correlation with the sum of defect scores (DS) in the late images (R=-0.47 to -0.59, p<0.05) and some parameters had a negative correlation with the washout rate (R=-0.50 to -0.55, p<0.05). In a total of 64 diabetic patients also, these parameters had a negative correlation with late DS (R=-0.28 to -0.35, p<0.05) and early DS (R=-0.27 to -0.32, p<0.05). The progress of diabetic cardiac parasympathetic dysfunction may parallel the sympathetic one. (author)

  10. Role of magnetic resonance imaging in entrapment and compressive neuropathy - what, where, and how to see the peripheral nerves on the musculoskeletal magnetic resonance image: part 1. Overview and lower extremity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sungjun [Yonsei University, Department of Diagnostic Radiology, College of Medicine, Seoul (Korea); Hanyang University, Kuri Hospital, Department of Diagnostic Radiology, College of Medicine, Kuri City, Kyunggi-do (Korea); Choi, Jin-Young; Huh, Yong-Min; Song, Ho-Taek; Lee, Sung-Ah [Yonsei University, Department of Diagnostic Radiology, College of Medicine, Seoul (Korea); Kim, Seung Min [Yonsei University, Department of Neurology, College of Medicine, Seoul (Korea); Suh, Jin-Suck [Yonsei University, Department of Diagnostic Radiology, College of Medicine, Seoul (Korea); Yonsei University, Research Institute of Radiological Science, College of Medicine, Seoul (Korea)

    2007-01-15

    The diagnosis of nerve entrapment and compressive neuropathy has been traditionally based on the clinical and electrodiagnostic examinations. As a result of improvements in the magnetic resonance (MR) imaging modality, it plays not only a fundamental role in the detection of space-occupying lesions but also a compensatory role in clinically and electrodiagnostically inconclusive cases. Although ultrasound has undergone further development in the past decades and shows high resolution capabilities, it has inherent limitations due to its operator dependency. We review the general concepts that should be known to evaluate the entrapment and compressive neuropathy in MR imaging. We also review the course of normal peripheral nerves, as well as various clinical demonstrations and pathological features of compressed and entrapped nerves in the lower extremities on MR imaging, according to the nerves involved. The common sites of nerve entrapment of the lower extremity are as follows: sciatic nerve around the piriformis muscle; tibial nerve at the popliteal fossa and tarsal tunnel, common peroneal nerve around the fibular neck, and digital nerve near the metatarsal head. Although MR imaging can depict the peripheral nerves in the extremities effectively, radiologists should be familiar with nerve pathways, common sites of nerve compression, and common space-occupying lesions resulting in nerve compression in MR imaging. (orig.)

  11. Role of magnetic resonance imaging in entrapment and compressive neuropathy - what, where, and how to see the peripheral nerves on the musculoskeletal magnetic resonance image: part 1. Overview and lower extremity

    International Nuclear Information System (INIS)

    Kim, Sungjun; Choi, Jin-Young; Huh, Yong-Min; Song, Ho-Taek; Lee, Sung-Ah; Kim, Seung Min; Suh, Jin-Suck

    2007-01-01

    The diagnosis of nerve entrapment and compressive neuropathy has been traditionally based on the clinical and electrodiagnostic examinations. As a result of improvements in the magnetic resonance (MR) imaging modality, it plays not only a fundamental role in the detection of space-occupying lesions but also a compensatory role in clinically and electrodiagnostically inconclusive cases. Although ultrasound has undergone further development in the past decades and shows high resolution capabilities, it has inherent limitations due to its operator dependency. We review the general concepts that should be known to evaluate the entrapment and compressive neuropathy in MR imaging. We also review the course of normal peripheral nerves, as well as various clinical demonstrations and pathological features of compressed and entrapped nerves in the lower extremities on MR imaging, according to the nerves involved. The common sites of nerve entrapment of the lower extremity are as follows: sciatic nerve around the piriformis muscle; tibial nerve at the popliteal fossa and tarsal tunnel, common peroneal nerve around the fibular neck, and digital nerve near the metatarsal head. Although MR imaging can depict the peripheral nerves in the extremities effectively, radiologists should be familiar with nerve pathways, common sites of nerve compression, and common space-occupying lesions resulting in nerve compression in MR imaging. (orig.)

  12. [Improvement of approach to performance of lumbar sympathetic blockade in patients with tissue ischemia of the lower extremities].

    Science.gov (United States)

    Panov, V M; Fesenko, U A; Kutsyn, V M

    2014-06-01

    New access for performance of sympathic blockade in region of aortal bifurcation, was elaborated, basing on calculations, conducted on 30 spiral computeric tomograms of lumbar and sacral parts of vertebral column. Application of the method permits to escape such complications, as a renal and the main vessels damage, the sympathetic nerves blockade, do not demand roentgenological control.

  13. Peroneal nerve injury in three patients with knee trauma: MR imaging and correlation with anatomic findings in volunteers and anatomic specimens

    Energy Technology Data Exchange (ETDEWEB)

    Trappeniers, Laurence; Osteaux, Michel [Department of Radiology, Vrije Universiteit Brussels, Brussels (Belgium); De Maeseneer, Michel [Department of Radiology, Vrije Universiteit Brussels, Brussels (Belgium); Department of Radiology, AZ VUB, Laarbeeklaan 101, 1090, Jette (Belgium); Van Roy, Peter [Department of Experimental Anatomy, Vrije Universiteit Brussels, Brussels (Belgium); Chaskis, Christo [Department of Neurosurgery, Vrije Universiteit Brussels, Brussels (Belgium)

    2003-07-01

    The aim of this article is to report on three patients with injuries of the peroneal nerve along the posterolateral aspect of the knee. Injuries in this area are less common than the injuries occurring at the level of the fibular head. In this article we report on three patients with posterolateral knee trauma who had peroneal nerve dysfunction. To better understand the precise location of the nerve on MR images, we performed MR imaging in five volunteers, and studied the position of the nerve on anatomic dissection (n=1) and anatomic slices (n=1). The common peroneal nerve is easily depicted on MR images and has a typical location along the posterior margin of the biceps tendon. Non-visualisation of the peroneal nerve at the posterolateral aspect of the knee, as seen on MR images, is consistent with nerve injury. Scar tissue at the posterolateral aspect of the knee indicates injury of this specific area, and involvement of the peroneal nerve is likely. (orig.)

  14. Imaging assessment of isolated lesions affecting cranial nerve III; Avaliacao por imagem das lesoes isoladas do III par craniano

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Marcelo de Mattos [Colegio Brasileiro de Radiologia e Diagnostico por Imagem (CBR), Sao Paulo, SP (Brazil)]. E-mail: cidbh@cidbh.com.br; Martins, Jose Carlos Tadeu [Sociedade Brasileira de Neuroradiologia, Sao Paulo, SP (Brazil)

    2005-05-15

    The aim of this study is to review the anatomy and main pathologic conditions affecting cranial nerve III using imaging studies, particularly magnetic resonance imaging. Imaging methods are essential in the evaluation of patients with suspected lesions of the oculomotor nerve once signs and symptoms are unspecific and a large number of diseases can affect cranial nerve III. A brief review of the literature is also presented. (author)

  15. The clinical value of cardiac sympathetic imaging in heart failure

    DEFF Research Database (Denmark)

    Christensen, Thomas Emil; Kjaer, Andreas; Hasbak, Philip

    2014-01-01

    The autonomic nervous system plays an important role in the pathology of heart failure. The single-photon emission computed tomography tracer iodine-123-metaiodobenzylguanidine ((123) I-MIBG) can be used to investigate the activity of the predominant neurotransmitter of the sympathetic nervous...

  16. Matured Hop Bittering Components Induce Thermogenesis in Brown Adipose Tissue via Sympathetic Nerve Activity.

    Directory of Open Access Journals (Sweden)

    Yumie Morimoto-Kobayashi

    Full Text Available Obesity is the principal symptom of metabolic syndrome, which refers to a group of risk factors that increase the likelihood of atherosclerosis. In recent decades there has been a sharp rise in the incidence of obesity throughout the developed world. Iso-α-acids, the bitter compounds derived from hops in beer, have been shown to prevent diet-induced obesity by increasing lipid oxidation in the liver and inhibition of lipid absorption from the intestine. Whereas the sharp bitterness induced by effective dose of iso-α-acids precludes their acceptance as a nutrient, matured hop bittering components (MHB appear to be more agreeable. Therefore, we tested MHB for an effect on ameliorating diet-induced body fat accumulation in rodents. MHB ingestion had a beneficial effect but, compared to iso-α-acids and despite containing structurally similar compounds, acted via different mechanisms to reduce body fat accumulation. MHB supplementation significantly reduced body weight gain, epididymal white adipose tissue weight, and plasma non-esterified free fatty acid levels in diet-induced obese mice. We also found that uncoupling protein 1 (UCP1 expression in brown adipose tissue (BAT was significantly increased in MHB-fed mice at both the mRNA and protein levels. In addition, MHB administration in rats induced the β-adrenergic signaling cascade, which is related to cAMP accumulation in BAT, suggesting that MHB could modulate sympathetic nerve activity innervating BAT (BAT-SNA. Indeed, single oral administration of MHB elevated BAT-SNA in rats, and this elevation was dissipated by subdiaphragmatic vagotomy. Single oral administration of MHB maintained BAT temperature at a significantly higher level than in control rats. Taken together, these findings indicate that MHB ameliorates diet-induced body fat accumulation, at least partly, by enhancing thermogenesis in BAT via BAT-SNA activation. Our data suggests that MHB is a useful tool for developing functional

  17. Revision on Renal Sympathetic Ablation in the Treatment of Resistant Hypertension.

    Science.gov (United States)

    Saraiva, Ana Filipa

    2016-01-01

    Hypertension is one of the most prevalent diseases in the world, with about 1 billion people affected and a possible increase to 1.5 billion by 2025. Despite advances in treatment, a proportion of patients remain resistant to conventional treatment and uncontrolled, and this can adversely affect future cardiovascular events and mortality. This alarming growth is already reflected in an important public health problem and one of the largest economic burdens of health, requiring new approaches and development of different strategies to fight this problem. This review will focus on the definition of resistant hypertension and its etiology, as well as in contemporary evidence supporting the usefulness of renal sympathetic denervation while addressing current and emerging devices, potential treatment indications in the future and unresolved issues that need to be addressed before renal sympathetic denervation can be adopted not only as a last resort exclusively for resistant hypertension. Finally an evaluation algorithm for patients with resistant hypertension which should be implemented before the execution of this technique will be proposed. Renal sympathetic denervation is a technique that possibly could have future implications in the population with hypertension, especially those with true resistant hypertension. This technique aims to reduce the renal sympathetic activation (a component in the pathophysiology of hypertension) through the destruction of the renal sympathetic nerves located in the adventitia of the renal arteries. There are several catheters that can be used; each with its specifications and therefore their selection should be made individually depending on the profile of the patient. However, a detailed pre-procedure evaluation is extremely important to exclude the large percentage of individuals with uncontrolled hypertension due to several factors that make it impossible to control blood pressure, but are likely to be corrected and as such should

  18. Effect of nerve activity on transport of nerve growth factor and dopamine β-hydroxylase antibodies in sympathetic neurones

    International Nuclear Information System (INIS)

    Lees, G.; Chubb, I.; Freeman, C.; Geffen, L.; Rush, R.

    1981-01-01

    The effect of nerve activity on the uptake and retrograde transport of nerve growth factor (NGF) and dopamine β-hydroxylase (DBH) antibodies was studied by injecting 125 I-labelled NGF and anti-DBH into the anterior eye chamber of guinea-pigs. Decentralization of the ipsilateral superior cervical ganglion (SCG) had no significant effect on the retrograde transport of either NGF or anti-DBH. Phenoxybenzamine produced a 50% increase in anti-DBH but not NGF accumulation and this effect was prevented by prior decentralization. This demonstrates that NGF is taken up independently of the retrieval of synaptic vesicle components. (Auth.)

  19. Recruitment pattern of sympathetic muscle neurons during premature ventricular contractions in heart failure patients and controls.

    Science.gov (United States)

    Maslov, Petra Zubin; Breskovic, Toni; Brewer, Danielle N; Shoemaker, J Kevin; Dujic, Zeljko

    2012-12-01

    Premature ventricular contractions (PVC) elicit larger bursts of multiunit muscle sympathetic nerve activity (MSNA), reflecting the ability to increase postganglionic axonal recruitment. We tested the hypothesis that chronic heart failure (CHF) limits the ability to recruit postganglionic sympathetic neurons as a response to PVC due to the excessive sympathetic activation in these patients. Sympathetic neurograms of sufficient signal-to-noise ratio were obtained from six CHF patients and from six similarly aged control individuals. Action potentials (APs) were extracted from the multiunit sympathetic neurograms during sinus rhythm bursts and during the post-PVC bursts. These APs were classified on the basis of the frequency per second, the content per burst, and the peak-to-peak amplitude, which formed the basis of binning the APs into active clusters. Compared with controls, CHF had higher APs per burst and higher number of active clusters per sinus rhythm burst (P < 0.05). Compared with sinus rhythm bursts, both groups increased AP frequency and the number of active clusters in the post-PVC burst (P < 0.05). However, compared with controls, the increase in burst integral, AP frequency, and APs per burst during the post-PVC burst was less in CHF patients. Nonetheless, the PVC-induced increase in active clusters per burst was similar between the groups. Thus, these CHF patients retained the ability to recruit larger APs but had a diminished ability to increase overall AP content.

  20. Circumferential targeted renal sympathetic nerve denervation with preservation of the renal arterial wall using intra-luminal ultrasound

    Science.gov (United States)

    Roth, Austin; Coleman, Leslie; Sakakura, Kenichi; Ladich, Elena; Virmani, Renu

    2015-03-01

    An intra-luminal ultrasound catheter system (ReCor Medical's Paradise System) has been developed to provide circumferential denervation of the renal sympathetic nerves, while preserving the renal arterial intimal and medial layers, in order to treat hypertension. The Paradise System features a cylindrical non-focused ultrasound transducer centered within a balloon that circulates cooling fluid and that outputs a uniform circumferential energy pattern designed to ablate tissues located 1-6 mm from the arterial wall and protect tissues within 1 mm. RF power and cooling flow rate are controlled by the Paradise Generator which can energize transducers in the 8.5-9.5 MHz frequency range. Computer simulations and tissue-mimicking phantom models were used to develop the proper power, cooling flow rate and sonication duration settings to provide consistent tissue ablation for renal arteries ranging from 5-8 mm in diameter. The modulation of these three parameters allows for control over the near-field (border of lesion closest to arterial wall) and far-field (border of lesion farthest from arterial wall, consisting of the adventitial and peri-adventitial spaces) depths of the tissue lesion formed by the absorption of ultrasonic energy and conduction of heat. Porcine studies have confirmed the safety (protected intimal and medial layers) and effectiveness (ablation of 1-6 mm region) of the system and provided near-field and far-field depth data to correlate with bench and computer simulation models. The safety and effectiveness of the Paradise System, developed through computer model, bench and in vivo studies, has been demonstrated in human clinical studies.

  1. Imaging before cryoablation of atrial fibrillation: is phrenic nerve palsy predictable?

    Science.gov (United States)

    Canpolat, Uğur; Aytemir, Kudret; Hızal, Mustafa; Hazırolan, Tuncay; Yorgun, Hikmet; Sahiner, Levent; Kaya, Ergun Barış; Oto, Ali

    2014-04-01

    Multidetector computerized tomography (MDCT) with improved temporal and spatial resolution is one of the most commonly used non-invasive tests for evaluation of pulmonary veins (PVs) and adjacent structures before cryoablation of atrial fibrillation (AF). Identification of spatial neighbouring of phrenic nerves is important to decrease likelihood of phrenic nerve palsy (PNP). The purpose of our study is to clarify the course of right phrenic nerve, its relations to PVs using 64-slice MDCT, and effect on occurrence of PNP. A total of 162 patients underwent MDCT with 3D reconstruction of left atrium prior to cryoablation for AF. The location of the right pericardiophrenic artery (RPA) was identified on axial images and artery distance to the right upper PV (RUPV) ostium was measured in 3D image. Right pericardiophrenic artery was detectable in 145 of 162 (89.5%) patients (52.4% male, age 54.5 ± 10.1 years, and 80.7% paroxysmal AF). Acute procedural success rate was 96.2%. Mean procedural and fluoroscopy times were 74.4 ± 6.2 and 15.7 ± 4.3 min. Transient right PNP was developed in four (2.75%) patients. RUPV ostium to RPA distance was lower in patients with PNP (P = 0.033). In multivariate regression analysis, only RUPV ostium to RPA distance (odds ratio: 2.95; 95% confidence interval: 1.76-4.66, P = 0.001) was the independent predictor of PNP occurrence during cryoablation. Our results revealed that pre-ablation cardiac imaging with 64-slice MDCT adequately detected RPA bordering the phrenic nerve, which was an important determinant of PNP development during cryoballoon-based AF ablation.

  2. Cranial nerve clock. Part II: functional MR imaging of brain activation during a declarative memory task.

    Science.gov (United States)

    Weiss, K L; Welsh, R C; Eldevik, P; Bieliauskas, L A; Steinberg, B A

    2001-12-01

    The authors performed this study to assess brain activation during encoding and successful recall with a declarative memory paradigm that has previously been demonstrated to be effective for teaching students about the cranial nerves. Twenty-four students underwent functional magnetic resonance (MR) imaging during encoding and recall of the name, number, and function of the 12 cranial nerves. The students viewed mnemonic graphic and text slides related to individual nerves, as well as their respective control slides. For the recall paradigm, students were prompted with the numbers 1-12 (test condition) intermixed with the number 14 (control condition). Subjects were tested about their knowledge of cranial nerves outside the MR unit before and after functional MR imaging. Students learned about the cranial nerves while undergoing functional MR imaging (mean post- vs preparadigm score, 8.1 +/- 3.4 [of a possible 12] vs 0.75 +/- 0.94, bilateral prefrontal cortex, left greater than right; P brain activation. Encoding revealed statistically significant activation in the bilateral prefrontal cortex, left greater than right [corrected]; bilateral occipital and parietal associative cortices, parahippocampus region, fusiform gyri, and cerebellum. Successful recall activated the left much more than the right prefrontal, parietal associative, and anterior cingulate cortices; bilateral precuneus and cerebellum; and right more than the left posterior cingulate. A predictable pattern of brain activation at functional MR imaging accompanies the encoding and successful recall of the cranial nerves with this declarative memory paradigm.

  3. Bed rest attenuates sympathetic and pressor responses to isometric exercise in antigravity leg muscles in humans.

    Science.gov (United States)

    Kamiya, Atsunori; Michikami, Daisaku; Shiozawa, Tomoki; Iwase, Satoshi; Hayano, Junichiro; Kawada, Toru; Sunagawa, Kenji; Mano, Tadaaki

    2004-05-01

    Although spaceflight and bed rest are known to cause muscular atrophy in the antigravity muscles of the legs, the changes in sympathetic and cardiovascular responses to exercises using the atrophied muscles remain unknown. We hypothesized that bed rest would augment sympathetic responses to isometric exercise using antigravity leg muscles in humans. Ten healthy male volunteers were subjected to 14-day 6 degrees head-down bed rest. Before and after bed rest, they performed isometric exercises using leg (plantar flexion) and forearm (handgrip) muscles, followed by 2-min postexercise muscle ischemia (PEMI) that continues to stimulate the muscle metaboreflex. These exercises were sustained to fatigue. We measured muscle sympathetic nerve activity (MSNA) in the contralateral resting leg by microneurography. In both pre- and post-bed-rest exercise tests, exercise intensities were set at 30 and 70% of the maximum voluntary force measured before bed rest. Bed rest attenuated the increase in MSNA in response to fatiguing plantar flexion by approximately 70% at both exercise intensities (both P antigravity leg muscles.

  4. Imaging symptomatics in recurrent facial nerve neuritis

    International Nuclear Information System (INIS)

    Slavchev, D.

    2001-01-01

    Gaining better insight into the etiology and pathogenesis of recurrent facial nerve neuritis requires the use of an appropriate imaging modality of examination. This is retrospective analysis of 106 patients with recurrent n. facialis neuritis, studied by conventional x-ray methods, including: segment roentgenography according to Schuller, Stenverse, Biezalski (in children), and hypocyloidal directly enlarged polytomography, with emphasis laid on their role in the diagnostic algorithm of study. Assessment is done of the Fallopian canal width and course, with a special reference to adjacent bony structures, having essential practical bearing on planning interventions for decompression of the nerve and chronic otomastoiditis treatment. In 30 % of the patients are observed inflammatory changes in the parafacial bony structures as an expression of inflammatory otogenic etiology of recurrent n. facialis neuritis, and in 7 % - eburneization of bony structures. The symptom of improved Fallopian canal visibility is documented in cases presenting chronic inflammatory processes involving parafacial cellular structures. (author)

  5. [Features of maxillary and mandibular nerves imaging during stem regional blockades. From paresthesia to 3D-CT guidance].

    Science.gov (United States)

    Zaytsev, A Yu; Nazaryan, D N; Kim, S Yu; Dubrovin, K V; Svetlov, V A; Khovrin, V V

    2014-01-01

    There are difficulties in procedure of regional block of 2 and 3 brunches of the trigeminal nerve despite availability of many different methods of nerves imaging. The difficulties are connected with complex anatomy structure. Neurostimulation not always effective and as a rule, is accompanied with wrong interpretation of movement response on stimulation. The changing of the tactics on paraesthesia search improves the situation. The use of new methods of nerves imaging (3D-CT) also allows decreasing the frequency of fails during procedure of regional block of the brunches of the trigeminal nerve.

  6. Diagnostic nerve ultrasonography

    International Nuclear Information System (INIS)

    Baeumer, T.; Grimm, A.; Schelle, T.

    2017-01-01

    For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. Using ultrasonography for peripheral nerve diagnostics. With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves. (orig.) [de

  7. Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves

    Energy Technology Data Exchange (ETDEWEB)

    Kijowski, Richard; Tuite, Michael; Sanford, Matthew [University of Wisconsin Hospital, Department of Radiology, Madison, WI (United States)

    2005-01-01

    Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears of the ulnar collateral ligament and lateral collateral ligament of the elbow with high sensitivity and specificity. Magnetic resonance imaging can determine the extent of tendon pathology in patients with medial epicondylitis and lateral epicondylitis. Magnetic resonance imaging can detect tears of the biceps tendon and triceps tendon and can distinguishing between partial and complete tendon rupture. Magnetic resonance imaging is also helpful in evaluating patients with nerve disorders at the elbow. (orig.)

  8. Reversible acute axonal polyneuropathy associated with Wernicke-Korsakoff syndrome: impaired physiological nerve conduction due to thiamine deficiency?

    Science.gov (United States)

    Ishibashi, S; Yokota, T; Shiojiri, T; Matunaga, T; Tanaka, H; Nishina, K; Hirota, H; Inaba, A; Yamada, M; Kanda, T; Mizusawa, H

    2003-05-01

    Acute axonal polyneuropathy and Wernicke-Korsakoff encephalopathy developed simultaneously in three patients. Nerve conduction studies (NCS) detected markedly decreased compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) with minimal conduction slowing; sympathetic skin responses (SSRs) were also notably decreased. Sural nerve biopsies showed only mild axonal degeneration with scattered myelin ovoid formation. The symptoms of neuropathy lessened within two weeks after an intravenous thiamine infusion. CMAPs, SNAPs, and SSRs also increased considerably. We suggest that this is a new type of peripheral nerve impairment: physiological conduction failure with minimal conduction delay due to thiamine deficiency.

  9. MR neurography of ulnar nerve entrapment at the cubital tunnel: a diffusion tensor imaging study

    International Nuclear Information System (INIS)

    Breitenseher, Julia B.; Berzaczy, Dominik; Nemec, Stefan F.; Weber, Michael; Prayer, Daniela; Kasprian, Gregor; Kranz, Gottfried; Sycha, Thomas; Hold, Alina

    2015-01-01

    MR neurography, diffusion tensor imaging (DTI) and tractography at 3 Tesla were evaluated for the assessment of patients with ulnar neuropathy at the elbow (UNE). Axial T2-weighted and single-shot DTI sequences (16 gradient encoding directions) were acquired, covering the cubital tunnel of 46 patients with clinically and electrodiagnostically confirmed UNE and 20 healthy controls. Cross-sectional area (CSA) was measured at the retrocondylar sulcus and FA and ADC values on each section along the ulnar nerve. Three-dimensional nerve tractography and T2-weighted neurography results were independently assessed by two raters. Patients showed a significant reduction of ulnar nerve FA values at the retrocondylar sulcus (p = 0.002) and the deep flexor fascia (p = 0.005). At tractography, a complete or partial discontinuity of the ulnar nerve was found in 26/40 (65 %) of patients. Assessment of T2 neurography was most sensitive in detecting UNE (sensitivity, 91 %; specificity, 79 %), followed by tractography (88 %/69 %). CSA and FA measurements were less effective in detecting UNE. T2-weighted neurography remains the most sensitive MR technique in the imaging evaluation of clinically manifest UNE. DTI-based neurography at 3 Tesla supports the MR imaging assessment of UNE patients by adding quantitative and 3D imaging data. (orig.)

  10. MR neurography of ulnar nerve entrapment at the cubital tunnel: a diffusion tensor imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Breitenseher, Julia B.; Berzaczy, Dominik; Nemec, Stefan F.; Weber, Michael; Prayer, Daniela; Kasprian, Gregor [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Kranz, Gottfried; Sycha, Thomas [Medical University of Vienna, Department of Neurology, Vienna (Austria); Hold, Alina [Medical University of Vienna, Department of Plastic and Reconstructive Surgery, Vienna (Austria)

    2015-07-15

    MR neurography, diffusion tensor imaging (DTI) and tractography at 3 Tesla were evaluated for the assessment of patients with ulnar neuropathy at the elbow (UNE). Axial T2-weighted and single-shot DTI sequences (16 gradient encoding directions) were acquired, covering the cubital tunnel of 46 patients with clinically and electrodiagnostically confirmed UNE and 20 healthy controls. Cross-sectional area (CSA) was measured at the retrocondylar sulcus and FA and ADC values on each section along the ulnar nerve. Three-dimensional nerve tractography and T2-weighted neurography results were independently assessed by two raters. Patients showed a significant reduction of ulnar nerve FA values at the retrocondylar sulcus (p = 0.002) and the deep flexor fascia (p = 0.005). At tractography, a complete or partial discontinuity of the ulnar nerve was found in 26/40 (65 %) of patients. Assessment of T2 neurography was most sensitive in detecting UNE (sensitivity, 91 %; specificity, 79 %), followed by tractography (88 %/69 %). CSA and FA measurements were less effective in detecting UNE. T2-weighted neurography remains the most sensitive MR technique in the imaging evaluation of clinically manifest UNE. DTI-based neurography at 3 Tesla supports the MR imaging assessment of UNE patients by adding quantitative and 3D imaging data. (orig.)

  11. Normal and sonographic anatomy of selected peripheral nerves. Part III: Peripheral nerves of the lower limb.

    Science.gov (United States)

    Kowalska, Berta; Sudoł-Szopińska, Iwona

    2012-06-01

    The ultrasonographic examination is currently increasingly used in imaging peripheral nerves, serving to supplement the physical examination, electromyography and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive and well-tolerated by patients. The typical ultrasonographic picture of peripheral nerves as well as the examination technique have been discussed in part I of this article series, following the example of the median nerve. Part II of the series presented the normal anatomy and the technique for examining the peripheral nerves of the upper limb. This part of the article series focuses on the anatomy and technique for examining twelve normal peripheral nerves of the lower extremity: the iliohypogastric and ilioinguinal nerves, the lateral cutaneous nerve of the thigh, the pudendal, sciatic, tibial, sural, medial plantar, lateral plantar, common peroneal, deep peroneal and superficial peroneal nerves. It includes diagrams showing the proper positioning of the sonographic probe, plus USG images of the successively discussed nerves and their surrounding structures. The ultrasonographic appearance of the peripheral nerves in the lower limb is identical to the nerves in the upper limb. However, when imaging the lower extremity, convex probes are more often utilized, to capture deeply-seated nerves. The examination technique, similarly to that used in visualizing the nerves of upper extremity, consists of locating the nerve at a characteristic anatomic reference point and tracking it using the "elevator technique". All 3 parts of the article series should serve as an introduction to a discussion of peripheral nerve pathologies, which will be presented in subsequent issues of the "Journal of Ultrasonography".

  12. Depiction of the cranial nerves around the cavernous sinus by 3D reversed FISP with diffusion weighted imaging (3D PSIF-DWI)

    International Nuclear Information System (INIS)

    Ishida, Go; Oishi, Makoto; Jinguji, Shinya; Yoneoka, Yuichiro; Fujii, Yukihiko; Sato, Mitsuya

    2011-01-01

    The purpose of this study was to evaluate the anatomy of cranial nerves running in and around the cavernous sinus, we employed three-dimensional reversed fast imaging with steady-state precession (FISP) with diffusion weighted imaging (3D PSIF-DWI) on 3-T magnetic resonance (MR) system. After determining the proper parameters to obtain sufficient resolution of 3D PSIF-DWI, we collected imaging data of 20-side cavernous regions in 10 normal subjects. 3D PSIF-DWI provided high contrast between the cranial nerves and other soft tissues, fluid, and blood in all subjects. We also created volume-rendered images of 3D PSIF-DWI and anatomically evaluated the reliability of visualizing optic, oculomotor, trochlear, trigeminal, and abducens nerves on 3D PSIF-DWI. All 20 sets of cranial nerves were visualized and 12 trochlear nerves and 6 abducens nerves were partially identified. We also presented preliminary clinical experiences in two cases with pituitary adenomas. The anatomical relationship between the tumor and cranial nerves running in and around the cavernous sinus could be three-dimensionally comprehended by 3D PSIF-DWI and the volume-rendered images. In conclusion, 3D PSIF-DWI has great potential to provide high resolution 'cranial nerve imaging', which visualizes the whole length of the cranial nerves including the parts in the blood flow as in the cavernous sinus region. (author)

  13. [Depiction of the cranial nerves around the cavernous sinus by 3D reversed FISP with diffusion weighted imaging (3D PSIF-DWI)].

    Science.gov (United States)

    Ishida, Go; Oishi, Makoto; Jinguji, Shinya; Yoneoka, Yuichiro; Sato, Mitsuya; Fujii, Yukihiko

    2011-10-01

    To evaluate the anatomy of cranial nerves running in and around the cavernous sinus, we employed three-dimensional reversed fast imaging with steady-state precession (FISP) with diffusion weighted imaging (3D PSIF-DWI) on 3-T magnetic resonance (MR) system. After determining the proper parameters to obtain sufficient resolution of 3D PSIF-DWI, we collected imaging data of 20-side cavernous regions in 10 normal subjects. 3D PSIF-DWI provided high contrast between the cranial nerves and other soft tissues, fluid, and blood in all subjects. We also created volume-rendered images of 3D PSIF-DWI and anatomically evaluated the reliability of visualizing optic, oculomotor, trochlear, trigeminal, and abducens nerves on 3D PSIF-DWI. All 20 sets of cranial nerves were visualized and 12 trochlear nerves and 6 abducens nerves were partially identified. We also presented preliminary clinical experiences in two cases with pituitary adenomas. The anatomical relationship between the tumor and cranial nerves running in and around the cavernous sinus could be three-dimensionally comprehended by 3D PSIF-DWI and the volume-rendered images. In conclusion, 3D PSIF-DWI has great potential to provide high resolution "cranial nerve imaging", which visualizes the whole length of the cranial nerves including the parts in the blood flow as in the cavernous sinus region.

  14. High Spatial Resolution Imaging Mass Spectrometry of Human Optic Nerve Lipids and Proteins

    Science.gov (United States)

    Anderson, David M. G.; Spraggins, Jeffrey M.; Rose, Kristie L.; Schey, Kevin L.

    2015-06-01

    The human optic nerve carries signals from the retina to the visual cortex of the brain. Each optic nerve is comprised of approximately one million nerve fibers that are organized into bundles of 800-1200 fibers surrounded by connective tissue and supportive glial cells. Damage to the optic nerve contributes to a number of blinding diseases including: glaucoma, neuromyelitis optica, optic neuritis, and neurofibromatosis; however, the molecular mechanisms of optic nerve damage and death are incompletely understood. Herein we present high spatial resolution MALDI imaging mass spectrometry (IMS) analysis of lipids and proteins to define the molecular anatomy of the human optic nerve. The localization of a number of lipids was observed in discrete anatomical regions corresponding to myelinated and unmyelinated nerve regions as well as to supporting connective tissue, glial cells, and blood vessels. A protein fragment from vimentin, a known intermediate filament marker for astrocytes, was observed surrounding nerved fiber bundles in the lamina cribrosa region. S100B was also found in supporting glial cell regions in the prelaminar region, and the hemoglobin alpha subunit was observed in blood vessel areas. The molecular anatomy of the optic nerve defined by MALDI IMS provides a firm foundation to study biochemical changes in blinding human diseases.

  15. Sequential variation in brain functional magnetic resonance imaging after peripheral nerve injury: A rat study.

    Science.gov (United States)

    Onishi, Okihiro; Ikoma, Kazuya; Oda, Ryo; Yamazaki, Tetsuro; Fujiwara, Hiroyoshi; Yamada, Shunji; Tanaka, Masaki; Kubo, Toshikazu

    2018-04-23

    Although treatment protocols are available, patients experience both acute neuropathic pain and chronic neuropathic pain, hyperalgesia, and allodynia after peripheral nerve injury. The purpose of this study was to identify the brain regions activated after peripheral nerve injury using functional magnetic resonance imaging (fMRI) sequentially and assess the relevance of the imaging results using histological findings. To model peripheral nerve injury in male Sprague-Dawley rats, the right sciatic nerve was crushed using an aneurysm clip, under general anesthesia. We used a 7.04T MRI system. T 2 * weighted image, coronal slice, repetition time, 7 ms; echo time, 3.3 ms; field of view, 30 mm × 30 mm; pixel matrix, 64 × 64 by zero-filling; slice thickness, 2 mm; numbers of slices, 9; numbers of average, 2; and flip angle, 8°. fMR images were acquired during electrical stimulation to the rat's foot sole; after 90 min, c-Fos immunohistochemical staining of the brain was performed in rats with induced peripheral nerve injury for 3, 6, and 9 weeks. Data were pre-processed by realignment in the Statistical Parametric Mapping 8 software. A General Linear Model first level analysis was used to obtain T-values. One week after the injury, significant changes were detected in the cingulate cortex, insular cortex, amygdala, and basal ganglia; at 6 weeks, the brain regions with significant changes in signal density were contracted; at 9 weeks, the amygdala and hippocampus showed activation. Histological findings of the rat brain supported the fMRI findings. We detected sequential activation in the rat brain using fMRI after sciatic nerve injury. Many brain regions were activated during the acute stage of peripheral nerve injury. Conversely, during the chronic stage, activation of the amygdala and hippocampus may be related to chronic-stage hyperalgesia, allodynia, and chronic neuropathic pain. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. [Imaging anatomy of the cranial nerves using 3.0 Tesla MRI: a practical review for clinicians].

    Science.gov (United States)

    Chávez-Barba, Oscar; Martínez-Martínez, Lidieth; Cazares-Arellano, José Luis; Martínez-López, Manuel; Roldan-Valadez, Ernesto

    2011-01-01

    Magnetic resonance (MR) imaging is the method of choice to evaluate the cranial nerves (CN). These nerves constitute a group of structures that have acquired during their phylogenetic development a high degree of specialization. There are 12 pairs of CN to which we use their specific name or number. The olfactory (I) and optic (II) pairs are not real nerves but tracts from the encephalon. The spinal nerve (XI) derives from superior cervical segment of the spine. The other 9 pairs of CN are related with the brain stem. Although the skull base foramina can be seen on computed tomography, the nerves themselves can only be visualized in detail on MR. That means, in order to see the different segments of nerves I to XII, the right sequences must be used. It is important to provide detailed clinical information to the radiologist so that a tailored MR study can be performed. In this review, the basic imaging anatomy of the 12 CN is discussed and illustrated briefly with an emphasis on more advanced extra-axial anatomy, illustrated with high-resolution MR images. Clinicians looking for complete anatomic descriptions and/or MR illustrations are advised to consult specialized textbooks considering it is not possible to describe all of the anatomy in one article. This manuscript is intended to be a practical review for clinicians.

  17. Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats.

    Science.gov (United States)

    Li, Peng; Huang, Pei-Pei; Yang, Yun; Liu, Chi; Lu, Yan; Wang, Fang; Sun, Wei; Kong, Xiang-Qing

    2017-01-01

    Li P, Huang P, Yang Y, Liu C, Lu Y, Wang F, Sun W, Kong X. Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats. J Appl Physiol 122: 121-129, 2017. First published October 14, 2016; doi:10.1152/japplphysiol.01019.2015-Sympathetic activity is enhanced in patients with essential or secondary hypertension, as well as in various hypertensive animal models. Therapeutic targeting of sympathetic activation is considered an effective antihypertensive strategy. We hypothesized that renal sympathetic denervation (RSD) attenuates hypertension and improves vascular remodeling and renal disease in the 2-kidney, 1-clip (2K1C) rat model. Rats underwent 2K1C modeling or sham surgery; then rats underwent RSD or sham surgery 4 wk later, thus resulting in four groups (normotensive-sham, normotensive-RSD, 2K1C-sham, and 2K1C-RSD). Norepinephrine was measured by ELISA. Echocardiography was used to assess heart function. Fibrosis and apoptosis were assessed by Masson and TUNEL staining. Changes in mean arterial blood pressure in response to hexamethonium and plasma norepinephrine levels were used to evaluate basal sympathetic nerve activity. The 2K1C modeling success rate was 86.8%. RSD reversed the elevated systolic blood pressure induced by 2K1C, but had no effect on body weight. Compared with rats in the 2K1C-sham group, rats in the 2K1C-RSD group showed lower left ventricular mass/body weight ratio, interventricular septal thickness in diastole, left ventricular end-systolic diameter, and left ventricular posterior wall thickness in systole, whereas fractional shortening and ejection fraction were higher. Right kidney apoptosis and left kidney hypertrophy were not changed by RSD. Arterial fibrosis was lower in animals in the 2K1C-RSD group compared with those in the 2K1C-sham group. RSD reduced plasma norepinephrine and basal sympathetic activity in rats in the 2K1C-RSD group compared with rats in the 2K1C-sham group. These

  18. Diffusion tensor imaging for nerve fiber bundles in the brain stem and spinocerebellar degeneration

    International Nuclear Information System (INIS)

    Honma, Tsuguo

    2009-01-01

    Diffusion tensor imaging (DTI) can create an image of the anisotropic nature of diffusion and express it quantitatively. Nerve fibers have a large anisotropic diffusion, and it is possible to obtain images of the nerve fiber bundle. The purpose of this study is to observe the nerve fiber bundles in the brain stem using DTI and study its potential for diagnosing the type of spinocerebellar degeneration (SCD). Fractional anisotropy (FA) maps and 3D-tractography images were obtained for 41 subjects with no brain stem abnormalities. We created an apparent diffusion coefficient (ADC) map and an FA map using DTI for 16 subjects in the disease group (11 with hereditary SCD and 5 with non-hereditary SCD) and 25 in the control group. The diffusion value of the pons and middle cerebellar peduncle was measured using ADC, and the degree of anisotropic diffusion was measured using FA. The pyramidal tract, superior cerebellar peduncle, and inferior cerebellar peduncle were clearly demonstrated for all cases. ADC for the middle cerebellar peduncle in spinocerebellar ataxin (SCA)1 was significantly higher, similar to that for the pons in dentatorubro-pallidoluysian atrophy (DRPLA). In MSA-C, ADC for both the pons and middle cerebellar peduncle was significantly elevated and FA was significantly decreased. There were no significant changes in SCA3. We could observe the nerve fiber bundles in the brain stem using DTI. FA and ADC measurements with DTI can aid in diagnosing the type of SCD. (author)

  19. The progression to permanent atrial fibrillation with congestive heart failure is associated with sympathetic nerve abnormality. A study with I-123 metaiodobenzylguanidine scintigraphy

    International Nuclear Information System (INIS)

    Kodama, Yusuke; Akutsu, Yasushi; Li, Hui-Ling; Kinohira, Yukihiko; Yamanaka, Hideyuki; Shinozuka, Akira; Katagiri, Takashi

    2005-01-01

    The aim of this study was to evaluate the relationship between congestive heart failure (CHF) and atrial fibrillation (AF) using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphic imaging. Ninety-two AF patients (47 male and 45 female patients; mean age, 67±13 years) who did not suffer from structural heart disease or myocardial ischemia underwent MIBG scintigraphy. Global MIBG uptake was assessed by measuring the heart-to-mediastinal ratio (H/M) and washout rate (WR) on planar images, and the abnormal score (AS) was calculated on delayed MIBG single photon emission computed tomography images. Echocardiography was performed within a week after MIBG scintigraphy, to measure left ventricular ejection fraction (EF) and deceleration time (DT). The AF patients were divided into four groups: patients with permanent AF with (n=23, group A) or without (n=19, group B) a history of CHF, and patients with paroxysmal AF with (n=19, group C) or without (n=39, group D) a history of CHF. The H/M ratio was significantly lower in group A than in other groups (2.0±0.6 vs. group B: 2.7±0.6, group C: 2.3±0.5, and group D: 2.6±0.8, P<0.05), and in group C than in group D (P<0.05). Similarly, the WR was significantly higher in group A than in groups B and C (45.9±2.0 vs. group B: 38.9±1.9 and group C: 38.4±2.3, P<0.05). The AS was the highest in group A (19.7±8.2 vs. group B: 7.1±6.6, P<0.01; group C: 11.6±10.6 and group D: 13.5±9.0, P<0.05). The DT was significantly longer in group A than in groups B and D (222.0±59.4 vs. group B: 179.5±49.1, P<0.05 and group D: 177.9±37.1, P<0.01), but did not differ between groups A and C (222.0±59.4 vs. 197.4±51.1). There was no difference in EF among the groups. Although CHF with AF is associated with diastolic dysfunction, the progression to permanent AF from paroxysmal AF with CHF might be caused mainly by sympathetic nerve abnormality. (author)

  20. Imaging the diabetic foot

    International Nuclear Information System (INIS)

    Gold, R.H.; Tong, D.T.F.; Crim, J.R.; Seeger, L.L.

    1995-01-01

    Early and accurate diagnosis of infection or neuropathy of the diabetic foot is the key to successful management. Angiopathy leads to ischemia which, in combination with peripheral neuropathy, predisposes to pedal skin ulceration, the precursor of osteomyelitis. Chronic hyperglycemia promotes production of glycosylated end products which accumulate on endothelial proteins, causing ischemia of the vasa nervorum. When combined with axonal degeneration of the sensory nerves, the result is hypertrophic neuroarthropathy. Should the sympathetic nerve fibers also be damaged, the resultant loss of vasoconstrictive impulses leads to hyperemia and atrophic neuroarthropathy. Plain radiography, although less sensitive than radionuclide, magnetic resonance (MR), and computed tomographic examinations, should be the initial procedure for imaging suspected osteomyelitis in the diabetic patient. If the radiographs are normal but the clinical suspicion of osteomyelitis is strong, a three-phase 99m Tc-MDP scan or MR imaging is recommended. An equivocal 99m Tc-MDP scan should be followed by MR imaging. To exclude osteomyelitis at a site of neuroarthropathy, a 111 In white blood cell scan is preferable. To obtain a specimen of bone for bacteriological studies, percutaneous core biopsy is the procedure of choice, with the entrance of the needle well beyond the edge of the subjacent ulcer. (orig.)

  1. Imaging the diabetic foot

    Energy Technology Data Exchange (ETDEWEB)

    Gold, R.H. [Dept. of Radiological Sciences, UCLA School of Medicine, Los Angeles, CA (United States); Tong, D.T.F. [Dept. of Radiological Sciences, UCLA School of Medicine, Los Angeles, CA (United States); Crim, J.R. [Durham Radiology Associates, Durham, NC (United States); Seeger, L.L. [Dept. of Radiological Sciences, UCLA School of Medicine, Los Angeles, CA (United States)

    1995-11-01

    Early and accurate diagnosis of infection or neuropathy of the diabetic foot is the key to successful management. Angiopathy leads to ischemia which, in combination with peripheral neuropathy, predisposes to pedal skin ulceration, the precursor of osteomyelitis. Chronic hyperglycemia promotes production of glycosylated end products which accumulate on endothelial proteins, causing ischemia of the vasa nervorum. When combined with axonal degeneration of the sensory nerves, the result is hypertrophic neuroarthropathy. Should the sympathetic nerve fibers also be damaged, the resultant loss of vasoconstrictive impulses leads to hyperemia and atrophic neuroarthropathy. Plain radiography, although less sensitive than radionuclide, magnetic resonance (MR), and computed tomographic examinations, should be the initial procedure for imaging suspected osteomyelitis in the diabetic patient. If the radiographs are normal but the clinical suspicion of osteomyelitis is strong, a three-phase {sup 99m}Tc-MDP scan or MR imaging is recommended. An equivocal {sup 99m}Tc-MDP scan should be followed by MR imaging. To exclude osteomyelitis at a site of neuroarthropathy, a {sup 111}In white blood cell scan is preferable. To obtain a specimen of bone for bacteriological studies, percutaneous core biopsy is the procedure of choice, with the entrance of the needle well beyond the edge of the subjacent ulcer. (orig.)

  2. MR tractography; Visualization of structure of nerve fiber system from diffusion weighted images with maximum intensity projection method

    Energy Technology Data Exchange (ETDEWEB)

    Kinosada, Yasutomi; Okuda, Yasuyuki (Mie Univ., Tsu (Japan). School of Medicine); Ono, Mototsugu (and others)

    1993-02-01

    We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology. (author).

  3. Tumefactive appearance of peripheral nerve involvement in hematologic malignancies: a new imaging association

    Energy Technology Data Exchange (ETDEWEB)

    Capek, Stepan [Mayo Clinic, Department of Neurosurgery, Rochester, Minnesota (United States); St. Anne' s University Hospital Brno, International Clinical Research Center, Brno (Czech Republic); Hebert-Blouin, Marie-Noelle [McGill University, Department of Neurologic Surgery, Montreal, Quebec (Canada); Puffer, Ross C.; Spinner, Robert J. [Mayo Clinic, Department of Neurosurgery, Rochester, Minnesota (United States); Martinoli, Carlo [Universita degli Studi di Genova, Department of Radiology, Genova (Italy); Frick, Matthew A.; Amrami, Kimberly K. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

    2015-04-29

    In neurolymphomatosis (NL), the affected nerves are typically described to be enlarged and hyperintense on T2W MR sequences and to avidly enhance on gadolinium-enhanced T1WI. This pattern is highly non-specific. We recently became aware of a ''tumefactive pattern'' of NL, neuroleukemiosis (NLK) and neuroplasmacytoma (NPLC), which we believe is exclusive to hematologic diseases affecting peripheral nerves. We defined a ''tumefactive'' appearance as complex, fusiform, hyperintense on T2WI, circumferential tumor masses encasing the involved peripheral nerves. The nerves appear to be infiltrated by the tumor. Both structures show varying levels of homogenous enhancement. We reviewed our series of 52 cases of NL in search of this pattern; two extra outside cases of NL, three cases of NLK, and one case of NPLC were added to the series. We identified 20 tumefactive lesions in 18 patients (14 NL, three NLK, one NPLC). The brachial plexus (n = 7) was most commonly affected, followed by the sciatic nerve (n = 6) and lumbosacral plexus (n = 3). Four patients had involvement of other nerves. All were proven by biopsy: the diagnosis was high-grade lymphoma (n = 12), low-grade lymphoma (n = 3), acute leukemia (n = 2), and plasmacytoma (n = 1). We present a new imaging pattern of ''tumefactive'' neurolymphomatosis, neuroleukemiosis, or neuroplasmacytoma in a series of 18 cases. We believe this pattern is associated with hematologic diseases directly involving the peripheral nerves. Knowledge of this association can provide a clue to clinicians in establishing the correct diagnosis. Bearing in mind that tumefactive NL, NLK, and NPLC is a newly introduced imaging pattern, we still recommend to biopsy patients with suspicion of a malignancy. (orig.)

  4. MR imaging of the lumber spine; Visualization capability of the nerve root

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Kazumasa; Hieda, Hiroshi; Goto, Takeshi; Goto, Hiroshi; Koga, Hiromichi; Hiraoka, Kouji (Moji Rousai Hospital, Fukuoka (Japan))

    1991-01-01

    We studied visualization capability of the nerve root in mainly coronary section pattern using magnetic resonance imaging (MRI). MRI was carried out in 91 patients with lumbago and sciatica. Coronary section was additionally photographed in 58 cases of these patients (32 with intervertebral hernia, 20 with spinal canal stenosis, 2 with spondylolytic spondylolisthesis, 2 with compression fracture and the other 2 patients). The visualization capability of the nerve root was studied with photographing 2 pulse systems of the coronary section by using spin echo and field echo methods. The high signal area of the cerebrospinal fluid and nerve root in the normal lumbar vertebra was noted by field echo method, and pattern that is visualized by myelogram was obtained. The coincidence of the main foci (disturbed lesions of the nerve root) in the intervertebral hernia and coronary section pattern was noted in 21 of 32 cases (64.5%) with considerably high ratio. The condition of the nerve root in the blocked lesion was visualized in the spinal canal stenosis. (author).

  5. Normal and sonographic anatomy of selected peripheral nerves. Part III: Peripheral nerves of the lower limb

    Directory of Open Access Journals (Sweden)

    Berta Kowalska

    2012-06-01

    Full Text Available The ultrasonographic examination is currently increasingly used in imaging peripheral nerves, serving to supplement the physical examination, electromyography and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive and well-tolerated by patients. The typical ultrasonographic picture of peripheral nerves as well as the examination technique have been discussed in part I of this article series, following the example of the median nerve. Part II of the series presented the normal anatomy and the technique for examining the peripheral nerves of the upper limb. This part of the article series focuses on the anatomy and technique for examining twelve normal peripheral nerves of the lower extremity: the iliohypogastric and ilioinguinal nerves, the lateral cutaneous nerve of the thigh, the pudendal, sciatic, tibial, sural, medial plantar, lateral plantar, common peroneal, deep peroneal and superficial peroneal nerves. It includes diagrams showing the proper positioning of the sonographic probe, plus USG images of the successively discussed nerves and their surrounding structures. The ultrasonographic appearance of the peripheral nerves in the lower limb is identical to the nerves in the upper limb. However, when imaging the lower extremity, convex probes are more often utilized, to capture deeply-seated nerves. The examination technique, similarly to that used in visualizing the nerves of upper extremity, consists of locating the nerve at a characteristic anatomic reference point and tracking it using the “elevator technique”. All 3 parts of the article series should serve as an introduction to a discussion of peripheral nerve pathologies, which will be presented in subsequent issues of the “Journal of Ultrasonography”.

  6. Abnormal sympathetic nerve activity in women exposed to cigarette smoke: a potential mechanism to explain increased cardiac risk.

    Science.gov (United States)

    Middlekauff, Holly R; Park, Jeanie; Agrawal, Harsh; Gornbein, Jeffrey A

    2013-11-15

    In women, cardiac deaths attributable to tobacco exposure have reached the same high levels as men. Normally, sympathetic nerve activity (SNA) fluctuates according to the menstrual phase, but in habitual smokers, SNA levels remain constant. Our purpose is to extend these observations to other groups of women exposed to tobacco smoke and to explore potential mechanisms. We hypothesize that women exposed to secondhand smoke, but not former smokers, have nonfluctuating SNA compared with never smokers, and that impaired baroreflex suppression of SNA, and/or heightened central SNA responses, underlie this nonfluctuating SNA. We also hypothesize that female smokers have impaired nocturnal blood pressure dipping, normally mediated by modulation of SNA. In 49 females (19 never, 12 current, 9 former, 9 passive smokers), SNA was recorded (microneurography) during high- and low-hormone ovarian phases at rest, during pharmacological baroreflex testing, and during the cold pressor test (CPT). Twenty-four hour blood pressure (BP) monitoring was performed. Current and passive smokers, but not former smokers, had a nonfluctuating pattern of SNA, unlike never smokers in whom SNA varied with the menstrual phase. Baroreflex control of SNA was significantly blunted in current smokers, independent of menstrual phase. In passive smokers, SNA response to CPT was markedly increased. Nondipping was unexpectedly high in all groups. SNA does not vary during the menstrual cycle in active and passive smokers, unlike never and former smokers. Baroreflex control of SNA is blunted in current smokers, whereas SNA response to CPT is heightened in passive smokers. Smoking cessation is associated with return of the altered SNA pattern to normal.

  7. Chondromyxoid fibroma of the mastoid facial nerve canal mimicking a facial nerve schwannoma.

    Science.gov (United States)

    Thompson, Andrew L; Bharatha, Aditya; Aviv, Richard I; Nedzelski, Julian; Chen, Joseph; Bilbao, Juan M; Wong, John; Saad, Reda; Symons, Sean P

    2009-07-01

    Chondromyxoid fibroma of the skull base is a rare entity. Involvement of the temporal bone is particularly rare. We present an unusual case of progressive facial nerve paralysis with imaging and clinical findings most suggestive of a facial nerve schwannoma. The lesion was tubular in appearance, expanded the mastoid facial nerve canal, protruded out of the stylomastoid foramen, and enhanced homogeneously. The only unusual imaging feature was minor calcification within the tumor. Surgery revealed an irregular, cystic lesion. Pathology diagnosed a chondromyxoid fibroma involving the mastoid portion of the facial nerve canal, destroying the facial nerve.

  8. Improved identification of cranial nerves using paired-agent imaging: topical staining protocol optimization through experimentation and simulation

    Science.gov (United States)

    Torres, Veronica C.; Wilson, Todd; Staneviciute, Austeja; Byrne, Richard W.; Tichauer, Kenneth M.

    2018-03-01

    Skull base tumors are particularly difficult to visualize and access for surgeons because of the crowded environment and close proximity of vital structures, such as cranial nerves. As a result, accidental nerve damage is a significant concern and the likelihood of tumor recurrence is increased because of more conservative resections that attempt to avoid injuring these structures. In this study, a paired-agent imaging method with direct administration of fluorophores is applied to enhance cranial nerve identification. Here, a control imaging agent (ICG) accounts for non-specific uptake of the nerve-targeting agent (Oxazine 4), and ratiometric data analysis is employed to approximate binding potential (BP, a surrogate of targeted biomolecule concentration). For clinical relevance, animal experiments and simulations were conducted to identify parameters for an optimized stain and rinse protocol using the developed paired-agent method. Numerical methods were used to model the diffusive and kinetic behavior of the imaging agents in tissue, and simulation results revealed that there are various combinations of stain time and rinse number that provide improved contrast of cranial nerves, as suggested by optimal measures of BP and contrast-to-noise ratio.

  9. Effects of renal sympathetic denervation on cardiac sympathetic activity and function in patients with therapy resistant hypertension

    NARCIS (Netherlands)

    van Brussel, Peter M.; Eeftinck Schattenkerk, Daan W.; Dobrowolski, Linn C.; de Winter, Robbert J.; Reekers, Jim A.; Verberne, Hein J.; Vogt, Liffert; van den Born, Bert-Jan H.

    2016-01-01

    Renal sympathetic denervation (RSD) is currently being investigated in multiple studies of sympathetically driven cardiovascular diseases such as heart failure and arrhythmias. Our aim was to assess systemic and cardiac sympatholytic effects of RSD by the measurement of cardiac sympathetic activity

  10. Clinical and imaging characteristics of foraminal nerve root disorders of the lumbar spine

    International Nuclear Information System (INIS)

    Nishi, Tomio; Tani, Takayuki; Suzuki, Norio; Aonuma, Hiroshi

    2009-01-01

    We analyzed cases of lumbar nerve root compression at intervertebral foramina, by comparing 19 cases of foraminal stenosis (FS), and 38 cases of foraminal hernia (FH) with 21 cases of lumbar canal stenosis (LCS). Japan Orthopedic Association (JOA) scores, intervertebral disc degeneration, anatomical measurements of the nerve root foramina and the MRI findings were reviewed. The scores for pain in the lower extremities, and walking ability were both lowest in the FS group. The scores for low back pain, lower extremities, and sensory disturbances were lowest in the FH group. Anterior-posterior diameters of the nerve root foramina were smaller in the FS group and FH group than in the LCS group. More degenerated discs and short length of upper part of the nerve root foramina were seen in FS group than in the other groups. The MRI images of so-called black out nerve root foramina were positive in 63.6% of FS cases, 75% of FH cases. (author)

  11. Comparison of percutaneous electrical nerve stimulation and ultrasound imaging for nerve localization

    NARCIS (Netherlands)

    Wegener, J. T.; Boender, Z. J.; Preckel, B.; Hollmann, M. W.; Stevens, M. F.

    2011-01-01

    Background. Percutaneous nerve stimulation (PNS) is a non-invasive technique to localize superficial nerves before performing peripheral nerve blocks, but its precision has never been evaluated by high-resolution ultrasound. This study compared stimulating points at the skin with the position of

  12. Comparison of longitudinal excursion of a nerve-phantom model using quantitative ultrasound imaging and motion analysis system methods: A convergent validity study.

    Science.gov (United States)

    Paquette, Philippe; El Khamlichi, Youssef; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

    2017-08-01

    Quantitative ultrasound imaging is gaining popularity in research and clinical settings to measure the neuromechanical properties of the peripheral nerves such as their capability to glide in response to body segment movement. Increasing evidence suggests that impaired median nerve longitudinal excursion is associated with carpal tunnel syndrome. To date, psychometric properties of longitudinal nerve excursion measurements using quantitative ultrasound imaging have not been extensively investigated. This study investigates the convergent validity of the longitudinal nerve excursion by comparing measures obtained using quantitative ultrasound imaging with those determined with a motion analysis system. A 38-cm long rigid nerve-phantom model was used to assess the longitudinal excursion in a laboratory environment. The nerve-phantom model, immersed in a 20-cm deep container filled with a gelatin-based solution, was moved 20 times using a linear forward and backward motion. Three light-emitting diodes were used to record nerve-phantom excursion with a motion analysis system, while a 5-cm linear transducer allowed simultaneous recording via ultrasound imaging. Both measurement techniques yielded excellent association ( r  = 0.99) and agreement (mean absolute difference between methods = 0.85 mm; mean relative difference between methods = 7.48 %). Small discrepancies were largely found when larger excursions (i.e. > 10 mm) were performed, revealing slight underestimation of the excursion by the ultrasound imaging analysis software. Quantitative ultrasound imaging is an accurate method to assess the longitudinal excursion of an in vitro nerve-phantom model and appears relevant for future research protocols investigating the neuromechanical properties of the peripheral nerves.

  13. Neural correlates of fear-induced sympathetic response associated with the peripheral temperature change rate.

    Science.gov (United States)

    Yoshihara, Kazufumi; Tanabe, Hiroki C; Kawamichi, Hiroaki; Koike, Takahiko; Yamazaki, Mika; Sudo, Nobuyuki; Sadato, Norihiro

    2016-07-01

    Activation of the sympathetic nervous system is essential for coping with environmental stressors such as fearful stimuli. Recent human imaging studies demonstrated that activity in some cortical regions, such as the anterior cingulate cortex (ACC) and anterior insula cortex (aIC), is related to sympathetic activity. However, little is known about the functional brain connectivity related to sympathetic response to fearful stimuli. The participants were 32 healthy, right-handed volunteers. Functional magnetic resonance imaging (fMRI) was used to examine brain activity when watching horror and control movies. Fingertip temperature was taken during the scanning as a measure of sympathetic response. The movies were watched a second time, and the degree of fear (9-point Likert-type scale) was evaluated every three seconds. The brain activity of the ACC, bilateral aIC, and bilateral anterior prefrontal cortex (aPFC) was correlated with the change rate of fingertip temperature, with or without fearful stimuli. Functional connectivity analysis revealed significantly greater positive functional connectivity between the amygdala and the ACC and between the amygdala and the aIC when watching the horror movie than when watching the control movie. Whole-brain psycho-physiological interaction (PPI) analysis revealed that the functional connectivity between the left amygdala and the ACC was modulated according to the fear rating. Our results indicate that the increased functional connectivity between the left amygdala and the ACC represents a sympathetic response to fearful stimuli. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Sympathetic dysfunction in vasovagal syncope and the postural orthostatic tachycardia syndrome

    Directory of Open Access Journals (Sweden)

    Elisabeth eLambert

    2014-07-01

    Full Text Available Orthostatic intolerance is the inability to tolerate the upright posture and is relieved by recumbence. It most commonly affects young women and has a major impact on quality of life and psychosocial well being. Several forms of orthostatic intolerance have been described. The most common one is the recurrent vasovagal syncope (VVS phenotype which presents as a transient and abrupt loss of consciousness and postural tone that is followed by rapid recovery. Another common type of orthostatic intolerance is the postural orthostatic tachycardia syndrome (POTS which is characterized by an excessive rise in heart rate upon standing and is associated with symptoms of presyncope such as light-headedness, fatigue, palpitations and nausea. Maintenance of arterial pressure under condition of reduced central blood volume during the orthostasis is accomplished in large part through sympathetic efferent nerve traffic to the peripheral vasculature. Therefore sympathetic nervous system (SNS dysfunction is high on the list of possible contributors to the pathophysiology of orthostatic intolerance. Investigations into the role of the SNS in orthostatic intolerance have yielded mixed results. This review outlines the current knowledge of the function of the SNS in both VVS and POTS.

  15. Driven equilibrium (drive) MR imaging of the cranial nerves V-VIII: comparison with the T2-weighted 3D TSE sequence

    Energy Technology Data Exchange (ETDEWEB)

    Ciftci, E. E-mail: eciftcis7@hotmail.com; Anik, Yonca; Arslan, Arzu; Akansel, Gur; Sarisoy, Tahsin; Demirci, Ali

    2004-09-01

    Purpose: The aim of this study is to evaluate the efficacy of the driven equilibrium radio frequency reset pulse (DRIVE) on image quality and nerve detection when used in adjunction with T2-weighted 3D turbo spin-echo (TSE) sequence. Materials and methods: Forty-five patients with cranial nerve symptoms referable to the cerebellopontine angle (CPA) were examined using a T2-weighted 3D TSE pulse sequence with and without DRIVE. MR imaging was performed on a 1.5-T MRI scanner. In addition to the axial resource images, reformatted oblique sagittal, oblique coronal and maximum intensity projection (MIP) images of the inner ear were evaluated. The nerve identification and image quality were graded for the cranial nerves V-VIII as well as inner ear structures. These structures were chosen because fluid-solid interfaces existed due to the CSF around (the cranial nerves V-VIII) or the endolymph within (the inner ear structures). Statistical analysis was performed using the Wilcoxon test. P<0.05 was considered significant. Results: The addition of the DRIVE pulse shortens the scan time by 25%. T2-weighted 3D TSE sequence with DRIVE performed slightly better than the T2-weighted 3D TSE sequence without DRIVE in identifying the individual nerves. The image quality was also slightly better with DRIVE. Conclusion: The addition of the DRIVE pulse to the T2-weighted 3D TSE sequence is preferable when imaging the cranial nerves surrounded by the CSF, or fluid-filled structures because of shorter scan time and better image quality due to reduced flow artifacts.

  16. Driven equilibrium (drive) MR imaging of the cranial nerves V-VIII: comparison with the T2-weighted 3D TSE sequence

    International Nuclear Information System (INIS)

    Ciftci, E.; Anik, Yonca; Arslan, Arzu; Akansel, Gur; Sarisoy, Tahsin; Demirci, Ali

    2004-01-01

    Purpose: The aim of this study is to evaluate the efficacy of the driven equilibrium radio frequency reset pulse (DRIVE) on image quality and nerve detection when used in adjunction with T2-weighted 3D turbo spin-echo (TSE) sequence. Materials and methods: Forty-five patients with cranial nerve symptoms referable to the cerebellopontine angle (CPA) were examined using a T2-weighted 3D TSE pulse sequence with and without DRIVE. MR imaging was performed on a 1.5-T MRI scanner. In addition to the axial resource images, reformatted oblique sagittal, oblique coronal and maximum intensity projection (MIP) images of the inner ear were evaluated. The nerve identification and image quality were graded for the cranial nerves V-VIII as well as inner ear structures. These structures were chosen because fluid-solid interfaces existed due to the CSF around (the cranial nerves V-VIII) or the endolymph within (the inner ear structures). Statistical analysis was performed using the Wilcoxon test. P<0.05 was considered significant. Results: The addition of the DRIVE pulse shortens the scan time by 25%. T2-weighted 3D TSE sequence with DRIVE performed slightly better than the T2-weighted 3D TSE sequence without DRIVE in identifying the individual nerves. The image quality was also slightly better with DRIVE. Conclusion: The addition of the DRIVE pulse to the T2-weighted 3D TSE sequence is preferable when imaging the cranial nerves surrounded by the CSF, or fluid-filled structures because of shorter scan time and better image quality due to reduced flow artifacts

  17. A multiparametric assay for quantitative nerve regeneration evaluation

    OpenAIRE

    Weyn, Barbara; Van Remoortere, M; Nuydens, R; Meert, Theo; Van de Wouwer, G

    2005-01-01

    We introduce an assay for the semi-automated quantification of nerve regeneration by image analysis. Digital images of histological sections of regenerated nerves are recorded using an automated inverted microscope and merged into high-resolution mosaic images representing the entire nerve. These are analysed by a dedicated image-processing package that computes nerve-specific features (e.g. nerve area, fibre count, myelinated area) and fibre-specific features (area, perimeter, myelin sheet t...

  18. Recurrent postoperative CRPS I in patients with abnormal preoperative sympathetic function.

    Science.gov (United States)

    Ackerman, William E; Ahmad, Mahmood

    2008-02-01

    A complex regional pain syndrome of an extremity that has previously resolved can recur after repeat surgery at the same anatomic site. Complex regional pain syndrome is described as a disease of the autonomic nervous system. The purpose of this study was to evaluate preoperative and postoperative sympathetic function and the recurrence of complex regional pain syndrome type I (CRPS I) in patients after repeat carpal tunnel surgery. Thirty-four patients who developed CRPS I after initial carpal tunnel releases and required repeat open carpal tunnel surgeries were studied. Laser Doppler imaging (LDI) was used to assess preoperative sympathetic function 5-7 days prior to surgery and to assess postoperative sympathetic function 19-22 days after surgery or 20-22 days after resolution of the CRPS I. Sympathetic nervous system function was prospectively examined by testing reflex-evoked vasoconstrictor responses to sympathetic stimuli recorded with LDI of both hands. Patients were assigned to 1 of 2 groups based on LDI responses to sympathetic provocation. Group I (11 of 34) patients had abnormal preoperative LDI studies in the hands that had prior surgeries, whereas group II (23 of 34) patients had normal LDI studies. Each patient in this study had open repeat carpal tunnel surgery. In group I, 8 of 11 patients had recurrent CRPS I, whereas in group II, 3 of 23 patients had recurrent CRPS I. All of the recurrent CRPS I patients were successfully treated with sympathetic blockade, occupational therapy, and pharmacologic modalities. Repeat LDI after recurrent CRPS I resolution was abnormal in 8 of 8 group I patients and in 1 of 3 group II patients. CRPS I can recur after repeat hand surgery. Our study results may, however, identify those individuals who may readily benefit from perioperative therapies. Prognostic I.

  19. In vivo USPIO magnetic resonance imaging shows that minocycline mitigates macrophage recruitment to a peripheral nerve injury

    Directory of Open Access Journals (Sweden)

    Ghanouni Pejman

    2012-06-01

    Full Text Available Abstract Background Minocycline has proven anti-nociceptive effects, but the mechanism by which minocycline delays the development of allodynia and hyperalgesia after peripheral nerve injury remains unclear. Inflammatory cells, in particular macrophages, are critical components of the response to nerve injury. Using ultrasmall superparamagnetic iron oxide-magnetic resonance imaging (USPIO-MRI to monitor macrophage trafficking, the purpose of this project is to determine whether minocycline modulates macrophage trafficking to the site of nerve injury in vivo and, in turn, results in altered pain thresholds. Results Animal experiments were approved by Stanford IACUC. A model of neuropathic pain was created using the Spared Nerve Injury (SNI model that involves ligation of the left sciatic nerve in the left thigh of adult Sprague–Dawley rats. Animals with SNI and uninjured animals were then injected with/without USPIOs (300 μmol/kg IV and with/without minocycline (50 mg/kg IP. Bilateral sciatic nerves were scanned with a volume coil in a 7 T magnet 7 days after USPIO administration. Fluid-sensitive MR images were obtained, and ROIs were placed on bilateral sciatic nerves to quantify signal intensity. Pain behavior modulation by minocycline was measured using the Von Frey filament test. Sciatic nerves were ultimately harvested at day 7, fixed in 10% buffered formalin and stained for the presence of iron oxide-laden macrophages. Behavioral measurements confirmed the presence of allodynia in the neuropathic pain model while the uninjured and minocycline-treated injured group had significantly higher paw withdrawal thresholds (p  Conclusion Animals with neuropathic pain in the left hindpaw show increased trafficking of USPIO-laden macrophages to the site of sciatic nerve injury. Minocycline to retards the migration of macrophages to the nerve injury site, which may partly explain its anti-nociceptive effects. USPIO-MRI is an effective in

  20. Reduction of Blood Pressure Following After Renal Artery Adventitia Stripping During Total Nephroureterectomy: Potential Effect of Renal Sympathetic Denervation.

    Science.gov (United States)

    Okamura, Keisuke; Satou, Shunsuke; Setojima, Keita; Shono, Shinjiro; Miyajima, Shigero; Ishii, Tatsu; Shirai, Kazuyuki; Urata, Hidenori

    2018-05-16

    BACKGROUND Catheter-based renal sympathetic denervation has been reported to be effective for treatment resistance hypertension in Australia and Europe. However, in the blinded SYMPLICITY HTN-3 trial, renal denervation did not achieve a significant decrease in blood pressure (BP) in comparison to sham controls. There have been various discussions on the factors that influenced this result. CASE REPORT Two men on antihypertensive therapy underwent unilateral radical nephroureterectomy for cancer of the renal pelvis. When the renal artery adventitia was stripped and cauterized just before renal artery ligation, the measured BP of the 2 men increased after stripping adventitia and decreased gradually after cauterization of the renal artery. This was presumably due to removal of renal artery sympathetic nerves, similar to the mechanism of catheter-based renal sympathetic denervation, although anesthesia, fluid infusion, and/or mesenteric traction may have had an influence. CONCLUSIONS A similar strategy involving thoracolumbar sympathectomy was reported about 50 years ago. The clinically significant blood pressure reduction in these patients suggests renal denervation is effective.

  1. Three-dimensional display of peripheral nerves in the wrist region based on MR diffusion tensor imaging and maximum intensity projection post-processing

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Wen Quan, E-mail: dingwenquan1982@163.com [Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu (China); Zhou, Xue Jun, E-mail: zxj0925101@sina.com [Department of Radiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu (China); Tang, Jin Bo, E-mail: jinbotang@yahoo.com [Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu (China); Gu, Jian Hui, E-mail: gujianhuint@163.com [Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, Nantong, Jiangsu (China); Jin, Dong Sheng, E-mail: jindongshengnj@aliyun.com [Department of Radiology, Jiangsu Province Official Hospital, Nanjing, Jiangsu (China)

    2015-06-15

    Highlights: • 3D displays of peripheral nerves can be achieved by 2 MIP post-processing methods. • The median nerves’ FA and ADC values can be accurately measured by using DTI6 data. • Adopting 6-direction DTI scan and MIP can evaluate peripheral nerves efficiently. - Abstract: Objectives: To achieve 3-dimensional (3D) display of peripheral nerves in the wrist region by using maximum intensity projection (MIP) post-processing methods to reconstruct raw images acquired by a diffusion tensor imaging (DTI) scan, and to explore its clinical applications. Methods: We performed DTI scans in 6 (DTI6) and 25 (DTI25) diffusion directions on 20 wrists of 10 healthy young volunteers, 6 wrists of 5 patients with carpal tunnel syndrome, 6 wrists of 6 patients with nerve lacerations, and one patient with neurofibroma. The MIP post-processing methods employed 2 types of DTI raw images: (1) single-direction and (2) T{sub 2}-weighted trace. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of the median and ulnar nerves were measured at multiple testing sites. Two radiologists used custom evaluation scales to assess the 3D nerve imaging quality independently. Results: In both DTI6 and DTI25, nerves in the wrist region could be displayed clearly by the 2 MIP post-processing methods. The FA and ADC values were not significantly different between DTI6 and DTI25, except for the FA values of the ulnar nerves at the level of pisiform bone (p = 0.03). As to the imaging quality of each MIP post-processing method, there were no significant differences between DTI6 and DTI25 (p > 0.05). The imaging quality of single-direction MIP post-processing was better than that from T{sub 2}-weighted traces (p < 0.05) because of the higher nerve signal intensity. Conclusions: Three-dimensional displays of peripheral nerves in the wrist region can be achieved by MIP post-processing for single-direction images and T{sub 2}-weighted trace images for both DTI6 and DTI25

  2. WE-E-BRE-02: BEST IN PHYSICS (THERAPY) - Stereotactic Radiotherapy for Renal Sympathetic Ablation for the Treatment of Refractory Hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Maxim, P; Wheeler, M; Loo, B [Stanford University, Stanford, CA (United States); Maguire, P [Cyberheart, Inc., Sunnyvale, CA (United States)

    2014-06-15

    Purpose: To determine the safety and efficacy of stereotactic radiotherapy as a novel treatment for patients with refractory hypertension in a swine model. Uncontrolled hypertension is a significant contributor to morbidity and mortality, substantially increasing the risk of ischemic stroke, ischemic heart disease, and kidney failure. Methods: High-resolution computed tomography (CT) images of anesthetized pigs were acquired and treatment plans for each renal artery and nerve were developed using our clinically implemented treatment planning system. Stereotactic radiotherapy, 40Gy in single fraction was delivered bilaterally to the renal nerves using a state-of-the-art medical linear accelerator under image guidance utilizing dynamic conformal arcs. Dose to nearby critical organs was evaluated by dosevolume histogram analysis and correlated to toxicity data obtained through follow up pathology analysis. The animals were observed for six months with serial measurements of blood pressure, urine analysis, serum laboratories, and overall clinical and behavioral status. Results: All animals survived to the follow-up point without evidence of renal dysfunction (stable serum creatinine), skin changes, or behavioral changes that might suggest animal discomfort. Plasma norepinephrine levels (ng/ml) were followed monthly for 6 months. The average reduction observed was 63%, with the median reduction at 73.5%. Microscopic evaluation 4–6 weeks after treatment showed evidence of damage to the nerves around treated renal arteries. Considerable attenuation in pan neurofilament expression by immunohistochemistry was observed with some vacuolar changes indicative of injury. There was no histological or immunohistochemical evidence of damage to nearby spinal cord or spinal nerve root structures. Conclusion: Our preclinical studies have shown stereotactic radiotherapy to the renal sympathetic plexus to be safe and effective in reducing blood pressure, thus this approach holds great

  3. WE-E-BRE-02: BEST IN PHYSICS (THERAPY) - Stereotactic Radiotherapy for Renal Sympathetic Ablation for the Treatment of Refractory Hypertension

    International Nuclear Information System (INIS)

    Maxim, P; Wheeler, M; Loo, B; Maguire, P

    2014-01-01

    Purpose: To determine the safety and efficacy of stereotactic radiotherapy as a novel treatment for patients with refractory hypertension in a swine model. Uncontrolled hypertension is a significant contributor to morbidity and mortality, substantially increasing the risk of ischemic stroke, ischemic heart disease, and kidney failure. Methods: High-resolution computed tomography (CT) images of anesthetized pigs were acquired and treatment plans for each renal artery and nerve were developed using our clinically implemented treatment planning system. Stereotactic radiotherapy, 40Gy in single fraction was delivered bilaterally to the renal nerves using a state-of-the-art medical linear accelerator under image guidance utilizing dynamic conformal arcs. Dose to nearby critical organs was evaluated by dosevolume histogram analysis and correlated to toxicity data obtained through follow up pathology analysis. The animals were observed for six months with serial measurements of blood pressure, urine analysis, serum laboratories, and overall clinical and behavioral status. Results: All animals survived to the follow-up point without evidence of renal dysfunction (stable serum creatinine), skin changes, or behavioral changes that might suggest animal discomfort. Plasma norepinephrine levels (ng/ml) were followed monthly for 6 months. The average reduction observed was 63%, with the median reduction at 73.5%. Microscopic evaluation 4–6 weeks after treatment showed evidence of damage to the nerves around treated renal arteries. Considerable attenuation in pan neurofilament expression by immunohistochemistry was observed with some vacuolar changes indicative of injury. There was no histological or immunohistochemical evidence of damage to nearby spinal cord or spinal nerve root structures. Conclusion: Our preclinical studies have shown stereotactic radiotherapy to the renal sympathetic plexus to be safe and effective in reducing blood pressure, thus this approach holds great

  4. Remodelling of cardiac sympathetic re-innervation with thoracic spinal cord stimulation improves left ventricular function in a porcine model of heart failure.

    Science.gov (United States)

    Liao, Song-Yan; Liu, Yuan; Zuo, Mingliang; Zhang, Yuelin; Yue, Wensheng; Au, Ka-Wing; Lai, Wing-Hon; Wu, Yangsong; Shuto, Chika; Chen, Peter; Siu, Chung-Wah; Schwartz, Peter J; Tse, Hung-Fat

    2015-12-01

    Thoracic spinal cord stimulation (SCS) has been shown to improve left ventricular ejection fraction (LVEF) in heart failure (HF). Nevertheless, the optimal duration (intermittent vs. continuous) of stimulation and the mechanisms of action remain unclear. We performed chronic thoracic SCS at the level of T1-T3 (50 Hz, pulse width 0.2 ms) in 30 adult pigs with HF induced by myocardial infarction and rapid ventricular pacing for 4 weeks. All the animals were treated with daily oral metoprolol succinate (25 mg) plus ramipril (2.5 mg), and randomized to a control group (n = 10), intermittent SCS (4 h ×3, n = 10) or continuous SCS (24 h, n = 10) for 10 weeks. Serial measurements of LVEF and +dP/dt and serum levels of norepinephrine and B-type natriuretic peptide (BNP) were measured. After sacrifice, immunohistological studies of myocardial sympathetic and parasympathetic nerve sprouting and innervation were performed. Echocardiogram revealed a significant increase in LVEF and +dP/dt at 10 weeks in both the intermittent and continuous SCS group compared with controls (P < 0.05). In both SCS groups, there was diffuse sympathetic nerve sprouting over the infarct, peri-infarct, and normal regions compared with only the peri-infarct and infarct regions in the control group. In addition, sympathetic innervation at the peri-infarct and infarct regions was increased following SCS, but decreased in the control group. Myocardium norepinephrine spillover and serum BNP at 10 weeks was significantly decreased only in the continuous SCS group (P < 0.05). In a porcine model of HF, SCS induces significant remodelling of cardiac sympathetic innervation over the peri-infarct and infarct regions and is associated with improved LV function and reduced myocardial norepinephrine spillover. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  5. In vivo 3D neuroanatomical evaluation of periprostatic nerve plexus with 3T-MR Diffusion Tensor Imaging

    International Nuclear Information System (INIS)

    Panebianco, Valeria; Barchetti, Flavio; Sciarra, Alessandro; Marcantonio, Andrea; Zini, Chiara; Salciccia, Stefano; Collettini, Federico; Gentile, Vincenzo; Hamm, Bernard; Catalano, Carlo

    2013-01-01

    Objectives: To evaluate if Diffusion Tensor Imaging technique (DTI) can improve the visualization of periprostatic nerve fibers describing the location and distribution of entire neurovascular plexus around the prostate in patients who are candidates for prostatectomy. Materials and methods: Magnetic Resonance Imaging (MRI), including a 2D T2-weighted FSE sequence in 3 planes, 3D T2-weighted and DTI using 16 gradient directions and b = 0 and 1000, was performed on 36 patients. Three out of 36 patients were excluded from the analysis due to poor image quality (blurring N = 2, artifact N = 1). The study was approved by local ethics committee and all patients gave an informed consent. Images were evaluated by two radiologists with different experience in MRI. DTI images were analyzed qualitatively using dedicated software. Also 2D and 3D T2 images were independently considered. Results: 3D-DTI allowed description of the entire plexus of the periprostatic nerve fibers in all directions, while 2D and 3D T2 morphological sequences depicted part of the fibers, in a plane by plane analysis of fiber courses. DTI demonstrated in all patients the dispersion of nerve fibers around the prostate on both sides including the significant percentage present in the anterior and anterolateral sectors. Conclusions: DTI offers optimal representation of the widely distributed periprostatic plexus. If validated, it may help guide nerve-sparing radical prostatectomy

  6. Accelerated magnetic resonance diffusion tensor imaging of the median nerve using simultaneous multi-slice echo planar imaging with blipped CAIPIRINHA.

    Science.gov (United States)

    Filli, Lukas; Piccirelli, Marco; Kenkel, David; Boss, Andreas; Manoliu, Andrei; Andreisek, Gustav; Bhat, Himanshu; Runge, Val M; Guggenberger, Roman

    2016-06-01

    To investigate the feasibility of MR diffusion tensor imaging (DTI) of the median nerve using simultaneous multi-slice echo planar imaging (EPI) with blipped CAIPIRINHA. After federal ethics board approval, MR imaging of the median nerves of eight healthy volunteers (mean age, 29.4 years; range, 25-32) was performed at 3 T using a 16-channel hand/wrist coil. An EPI sequence (b-value, 1,000 s/mm(2); 20 gradient directions) was acquired without acceleration as well as with twofold and threefold slice acceleration. Fractional anisotropy (FA), mean diffusivity (MD) and quality of nerve tractography (number of tracks, average track length, track homogeneity, anatomical accuracy) were compared between the acquisitions using multivariate ANOVA and the Kruskal-Wallis test. Acquisition time was 6:08 min for standard DTI, 3:38 min for twofold and 2:31 min for threefold acceleration. No differences were found regarding FA (standard DTI: 0.620 ± 0.058; twofold acceleration: 0.642 ± 0.058; threefold acceleration: 0.644 ± 0.061; p ≥ 0.217) and MD (standard DTI: 1.076 ± 0.080 mm(2)/s; twofold acceleration: 1.016 ± 0.123 mm(2)/s; threefold acceleration: 0.979 ± 0.153 mm(2)/s; p ≥ 0.074). Twofold acceleration yielded similar tractography quality compared to standard DTI (p > 0.05). With threefold acceleration, however, average track length and track homogeneity decreased (p = 0.004-0.021). Accelerated DTI of the median nerve is feasible. Twofold acceleration yields similar results to standard DTI. • Standard DTI of the median nerve is limited by its long acquisition time. • Simultaneous multi-slice acquisition is a new technique for accelerated DTI. • Accelerated DTI of the median nerve yields similar results to standard DTI.

  7. Currant imaging of the 3rd, 4th and 6th cranial nerves

    International Nuclear Information System (INIS)

    Kerty, Emilia; Bakke, Soeren Jacob

    2001-01-01

    The ocular motor cranial nerves (III, IV, VI) control the eye movements in a near association with the higher cortical areas. Clinically, the most common presentation of abnormal ocular motility is double vision. Identifying the cause of ocular nerve pulsy can be difficult and a large percentage of such cases still remains undiagnosed, even in a new era of neuroradiological techniques. Close co-operation between the clinician and the radiologist is necessary for the selection of the best imaging methods for the specific clinical problem, in order to see the aetiological and topological diagnosis. The article provides a practical review of advances in neuroimaging of the ocular motor nerves. 4 figs., 2 tabs., 15 refs

  8. Bradykinin receptor blockade restores the baroreflex control of renal sympathetic nerve activity in cisplatin-induced renal failure rats.

    Science.gov (United States)

    Abdulla, M H; Duff, M; Swanton, H; Johns, E J

    2016-11-01

    This study investigated the effect of renal bradykinin B1 and B2 receptor blockade on the high- and low-pressure baroreceptor reflex regulation of renal sympathetic nerve activity (RSNA) in rats with cisplatin-induced renal failure. Cisplatin (5 mg/kg) or saline was given intraperitoneally 4 days prior to study. Following chloralose/urethane anaesthesia, rats were prepared for measurement of mean arterial pressure (MAP), heart rate and RSNA and received intrarenal infusions of either Lys-[des-Arg 9 , Leu 8 ]-bradykinin (LBK), a bradykinin B1 receptor blocker, or bradyzide (BZ), a bradykinin B2 receptor blocker. RSNA baroreflex gain curves and renal sympatho-inhibitory responses to volume expansion (VE) were obtained. In the control and renal failure groups, basal MAP (89 ± 3 vs. 80 ± 8 mmHg) and RSNA (2.0 ± 0.3 vs. 1.7 ± 0.6 μV.s) were similar but HR was lower in the latter group (331 ± 8 vs. 396 ± 9 beats/min). The baroreflex gain for RSNA in the renal failure rats was 39% (P renal failure rats. Intrarenal LBK infusion in the renal failure rats normalized the VE induced renal sympatho-inhibition whereas BZ only partially restored the response. These findings suggest that pro-inflammatory bradykinin acting at different receptors within the kidney generates afferent neural signals which impact differentially within the central nervous system on high- and low-pressure regulation of RSNA. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  9. Cardiac sympathetic neuronal damage precedes myocardial fibrosis in patients with Anderson-Fabry disease

    International Nuclear Information System (INIS)

    Imbriaco, Massimo; Piscopo, Valentina; Ponsiglione, Andrea; Nappi, Carmela; Puglia, Marta; Dell'Aversana, Serena; Spinelli, Letizia; Cuocolo, Alberto; Pellegrino, Teresa; Petretta, Mario; Riccio, Eleonora; Pisani, Antonio

    2017-01-01

    Cardiac sympathetic denervation may be detectable in patients with Anderson-Fabry disease (AFD), suggesting its usefulness for early detection of the disease. However, the relationship between sympathetic neuronal damage measured by 123 I-metaiodobenzylguanidine (MIBG) imaging with myocardial fibrosis on cardiac magnetic resonance (CMR) is still unclear. Cardiac sympathetic innervation was assessed by 123 I-MIBG single-photon emission computed tomography (SPECT) in 25 patients with genetically proved AFD. Within one month from MIBG imaging, all patients underwent contrast-enhanced CMR. MIBG defect size and fibrosis size on CMR were measured for the left ventricle (LV) and expressed as %LV. Patients were divided into three groups according to MIBG and CMR findings: (1) matched normal, without MIBG defects and without fibrosis on CMR (n = 10); (2) unmatched, with MIBG defect but without fibrosis (n = 5); and (3) matched abnormal, with MIBG defect and fibrosis (n = 10). The three groups did not differ with respect to age, gender, α-galactosidase, proteinuria, glomerular filtration rate, and troponin I, while New York Heart Association class (p = 0.008), LV hypertrophy (p = 0.05), and enzyme replacement therapy (p = 0.02) were different among groups. Although in patients with matched abnormal findings, there was a significant correlation between MIBG defect size and area of fibrosis at CMR (r 2 = 0.98, p < 0.001), MIBG defect size was larger than fibrosis size (26 ± 23 vs. 18 ± 13%LV, p = 0.02). Sympathetic neuronal damage is frequent in AFD patients, and it may precede myocardial damage, such as fibrosis. Thus, 123 I-MIBG imaging can be considered a challenging technique for early detection of cardiac involvement in AFD. (orig.)

  10. Lower cranial nerves.

    Science.gov (United States)

    Soldatos, Theodoros; Batra, Kiran; Blitz, Ari M; Chhabra, Avneesh

    2014-02-01

    Imaging evaluation of cranial neuropathies requires thorough knowledge of the anatomic, physiologic, and pathologic features of the cranial nerves, as well as detailed clinical information, which is necessary for tailoring the examinations, locating the abnormalities, and interpreting the imaging findings. This article provides clinical, anatomic, and radiological information on lower (7th to 12th) cranial nerves, along with high-resolution magnetic resonance images as a guide for optimal imaging technique, so as to improve the diagnosis of cranial neuropathy. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Anatomical Variations of Carotid Artery and Optic Nerve in Sphenoid Sinus Using Computerized Tomographic Imaging

    Directory of Open Access Journals (Sweden)

    Nikakhlagh

    2014-12-01

    Full Text Available Background Sphenoid sinus is surrounded by many vital vascular and nervous structures. In more than 20% of patients with chronic sinusitis, involvement of sphenoid sinus has been observed. Besides, sphenoid sinus is an appropriate route to access anterior and middle cranial fossa in surgery. Therefore, it is important to have an adequate knowledge about the contents of sphenoid sinus and its proximity for nasal endoscopy, sinus surgeries and neurosurgeries. Objectives The aim of this study was to study sphenoid sinus proximity with carotid artery and the optic nerve using computerized tomographic imaging. Materials and Methods In this prospective study, computerized tomographic images of sphenoid sinus of patients referred to Imam Khomeini and Apadana hospitals were studied. The images were studied regarding any bulging, as well as not having a bone covering in sphenoid sinus regarding internal carotid artery and optic nerve. Furthermore, unilateralness or bilateralness of their relationships was studied. Results Among 468 coronal and axial CT scan images of sphenoid sinus, 365 (78% showed post-sellar pneumatization and 103 (22% pre-sellar pneumatization. Regarding existence of internal septa, 346 (74% cases showed multiple septation, and the remaining images were reported to have a single septum. According to the reports of CT scan images, the existence of bulging as a result of internal carotid artery and uncovered artery were 4.22% and 5.8% in the right sinus, 4.9% and 5.4% in the left sinus, and 4.34% and 4.6% in both sinuses, respectively. According to the reports of CT scan images, existence of bulging as a result of optic nerve and uncovered nerve were 5.7% and 4.3% in the right sinus, 6% and 5.4% in the left sinus, and 12% and 3.2% in both sinuses, respectively. Conclusions Due to variability of sphenoid sinus pneumatization and the separator blade of the two sinus cavities, careful attention is required during sinus surgery to avoid

  12. Pneumatic antishock garment inflation activates the human sympathetic nervous system by abdominal compression.

    Science.gov (United States)

    Garvin, Nathan M; Levine, Benjamin D; Raven, Peter B; Pawelczyk, James A

    2014-01-01

    Pneumatic antishock garments (PASG) have been proposed to exert their blood pressure-raising effect mechanically, i.e. by increasing venous return and vascular resistance of the lower body. We tested whether, alternatively, PASG inflation activates the sympathetic nervous system. Five men and four women wore PASG while mean arterial pressure (MAP), muscle sympathetic nerve activity (MSNA), heart rate and stroke volume were measured. One leg bladder (LEG) and the abdominal bladder (ABD) of the trousers were inflated individually and in combination (ABD+LEG), at 60 or 90 mmHg for 3 min. By the end of 3 min of inflation, conditions that included the ABD region caused significant increases in MAP in a dose-dependent fashion (7 ± 2, 8 ± 3, 14 ± 4 and 13 ± 5 mmHg for ABD60, ABD+LEG60, ABD90 and ABD+LEG90, respectively, P < 0.05). Likewise, inflation that included ABD caused significant increases in total MSNA compared with control values [306 ± 70, 426 ± 98 and 247 ± 79 units for ABD60, ABD90 and ABD+LEG90, respectively, P < 0.05 (units = burst frequency × burst amplitude]. There were no changes in MAP or MSNA in the LEG-alone conditions. The ABD inflation also caused a significant decrease in stroke volume (-11 ± 3 and -10 ± 3 ml per beat in ABD90 and ABD+LEG90, respectively, P < 0.05) with no change in cardiac output. Neither cardiopulmonary receptor deactivation nor mechanical effects can account for a slowly developing rise in both sympathetic activity and blood pressure during ABD inflation. Rather, these data provide direct evidence that PASG inflation activates the sympathetic nervous system secondarily to abdominal, but not leg, compression.

  13. MR imaging of the major nerves about the elbow: cadaveric study examining the effect of flexion and extension of the elbow and pronation and supination of the forearm

    International Nuclear Information System (INIS)

    Kim, Young Sook; Yeh, Lee Ren; Trudell, D.; Resnick, D.

    1998-01-01

    Magnetic resonance (MR) imaging provides useful information in the evaluation of peripheral nerves. Recent advances in MR imaging allow for detailed depiction of the soft tissue structures of the elbow joint. Three major nerves are present about the elbow. Six cadaveric elbows were imaged to depict the normal anatomy of these nerves and to determine the best plane and position of the elbow for optimal visualization of each nerve. Axial images of the elbow in full extension with the forearm in supination allow identification of all major nerves. Axial images with the elbow in full flexion allow accurate assessment of the cubital tunnel and the ulner nerve. Axial images of the elbow in full extension with the forearm in pronation are helpful for assessment of the median and radial nerves in the forearm. (orig.)

  14. Recovery of the sub-basal nerve plexus and superficial nerve terminals after corneal epithelial injury in mice.

    Science.gov (United States)

    Downie, Laura E; Naranjo Golborne, Cecilia; Chen, Merry; Ho, Ngoc; Hoac, Cam; Liyanapathirana, Dasun; Luo, Carol; Wu, Ruo Bing; Chinnery, Holly R

    2018-06-01

    Our aim was to compare regeneration of the sub-basal nerve plexus (SBNP) and superficial nerve terminals (SNT) following corneal epithelial injury. We also sought to compare agreement when quantifying nerve parameters using different image analysis techniques. Anesthetized, female C57BL/6 mice received central 1-mm corneal epithelial abrasions. Four-weeks post-injury, eyes were enucleated and processed for PGP9.5 to visualize the corneal nerves using wholemount immunofluorescence staining and confocal microscopy. The percentage area of the SBNP and SNT were quantified using: ImageJ automated thresholds, ImageJ manual thresholds and manual tracings in NeuronJ. Nerve sum length was quantified using NeuronJ and Imaris. Agreement between methods was considered with Bland-Altman analyses. Four-weeks post-injury, the sum length of nerve fibers in the SBNP, but not the SNT, was reduced compared with naïve eyes. In the periphery, but not central cornea, of both naïve and injured eyes, nerve fiber lengths in the SBNP and SNT were strongly correlated. For quantifying SBNP nerve axon area, all image analysis methods were highly correlated. In the SNT, there was poor correlation between manual methods and auto-thresholding, with a trend towards underestimating nerve fiber area using auto-thresholding when higher proportions of nerve fibers were present. In conclusion, four weeks after superficial corneal injury, there is differential recovery of epithelial nerve axons; SBNP sum length is reduced, however the sum length of SNTs is similar to naïve eyes. Care should be taken when selecting image analysis methods to compare nerve parameters in different depths of the corneal epithelium due to differences in background autofluorescence. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Ultra-high field upper extremity peripheral nerve and non-contrast enhanced vascular imaging.

    Directory of Open Access Journals (Sweden)

    Shailesh B Raval

    Full Text Available The purpose of this study was to explore the efficacy of Ultra-high field [UHF] 7 Tesla [T] MRI as compared to 3T MRI in non-contrast enhanced [nCE] imaging of structural anatomy in the elbow, forearm, and hand [upper extremity].A wide range of sequences including T1 weighted [T1] volumetric interpolate breath-hold exam [VIBE], T2 weighted [T2] double-echo steady state [DESS], susceptibility weighted imaging [SWI], time-of-flight [TOF], diffusion tensor imaging [DTI], and diffusion spectrum imaging [DSI] were optimized and incorporated with a radiofrequency [RF] coil system composed of a transverse electromagnetic [TEM] transmit coil combined with an 8-channel receive-only array for 7T upper extremity [UE] imaging. In addition, Siemens optimized protocol/sequences were used on a 3T scanner and the resulting images from T1 VIBE and T2 DESS were compared to that obtained at 7T qualitatively and quantitatively [SWI was only qualitatively compared]. DSI studio was utilized to identify nerves based on analysis of diffusion weighted derived fractional anisotropy images. Images of forearm vasculature were extracted using a paint grow manual segmentation method based on MIPAV [Medical Image Processing, Analysis, and Visualization].High resolution and high quality signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]-images of the hand, forearm, and elbow were acquired with nearly homogeneous 7T excitation. Measured [performed on the T1 VIBE and T2 DESS sequences] SNR and CNR values were almost doubled at 7T vs. 3T. Cartilage, synovial fluid and tendon structures could be seen with higher clarity in the 7T T1 and T2 weighted images. SWI allowed high resolution and better quality imaging of large and medium sized arteries and veins, capillary networks and arteriovenous anastomoses at 7T when compared to 3T. 7T diffusion weighted sequence [not performed at 3T] demonstrates that the forearm nerves are clearly delineated by fiber tractography. The

  16. Renal Sympathetic Denervation by CT-scan-Guided Periarterial Ethanol Injection in Sheep

    Energy Technology Data Exchange (ETDEWEB)

    Firouznia, Kavous, E-mail: k-firouznia@yahoo.com; Hosseininasab, Sayed jaber, E-mail: dr.hosseininasab@gmail.com [Tehran University of Medical Sciences (TMUS), Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Amanpour, Saeid, E-mail: saeidamanpour@yahoo.com [Tehran University of Medical Science, Cancer Models Research Center, Cancer Institute of Iran (Iran, Islamic Republic of); Haj-Mirzaian, Arya, E-mail: arya.mirzaian@gmail.com [Tehran University of Medical Science, Department of Radiology and Imaging, MIC, Imam Khomeini Hospital (Iran, Islamic Republic of); Miri, Roza, E-mail: rosa.miri@yahoo.com [Tehran University of Medical Science, Department of Pathology, Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Muhammadnejad, Ahad, E-mail: mohamadnejad@yahoo.com [Tehran University of Medical Science, Cancer Research Center, Cancer Institute of Iran (Iran, Islamic Republic of); Muhammadnejad, Samad, E-mail: s-muhammadnejad@sina.tums.ac.ir [Tehran University of Medical Sciences, Research Center for Molecular and Cellular Imaging (Iran, Islamic Republic of); Jalali, Amir H., E-mail: amirjalali51@yahoo.com [Tehran University of Medical Sciences (TMUS), Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Ahmadi, Farrokhlagha, E-mail: ahmadi@tums.ac.ir [Tehran University of Medical Sciences, Nephrology Research Center, Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Rokni-Yazdi, Hadi, E-mail: rokniyaz@tums.ac.ir [Tehran University of Medical Sciences (TMUS), Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Imam Khomeini Hospital Complex (Iran, Islamic Republic of)

    2015-08-15

    BackgroundRenal nerves are a recent target in the treatment of hypertension. Renal sympathetic denervation (RSD) is currently performed using catheter-based radiofrequency ablation (RFA) and because this method has limitations, percutaneous magnetic resonance (MR)-guided periarterial ethanol injection is a suggested alternative. However, few studies have been conducted on the effectiveness of percutaneous ethanol injection for RSD.AimTo evaluate the feasibility, efficacy, and complications of computed tomography (CT)-guided periarterial ethanol injection.MethodsEthanol (10 ml, 99.6 %) was injected around the right renal artery in six sheep under CT guidance with the left kidney serving as a control. Before and after the intervention, the sheep underwent MR imaging studies and the serum creatinine level was measured. One month after the intervention, the sheep were euthanized and norepinephrine (NE) concentration in the renal parenchyma was measured to evaluate the efficacy of the procedure. The treated tissues were also examined histopathologically to evaluate vascular, parenchymal, and neural injury.ResultsThe right kidney parenchymal NE concentration decreased significantly compared with the left kidney after intervention (average reduction: 40 %, P = 0.0016). Histologic examination revealed apparent denervation with no other vascular or parenchymal injuries observed in the histological and imaging studies.ConclusionEffective and feasible RSD was achieved using CT-guided periarterial ethanol injection. This technique may be a potential alternative to catheter-based RFA in the treatment of hypertension.

  17. Renal Sympathetic Denervation by CT-scan-Guided Periarterial Ethanol Injection in Sheep

    International Nuclear Information System (INIS)

    Firouznia, Kavous; Hosseininasab, Sayed jaber; Amanpour, Saeid; Haj-Mirzaian, Arya; Miri, Roza; Muhammadnejad, Ahad; Muhammadnejad, Samad; Jalali, Amir H.; Ahmadi, Farrokhlagha; Rokni-Yazdi, Hadi

    2015-01-01

    BackgroundRenal nerves are a recent target in the treatment of hypertension. Renal sympathetic denervation (RSD) is currently performed using catheter-based radiofrequency ablation (RFA) and because this method has limitations, percutaneous magnetic resonance (MR)-guided periarterial ethanol injection is a suggested alternative. However, few studies have been conducted on the effectiveness of percutaneous ethanol injection for RSD.AimTo evaluate the feasibility, efficacy, and complications of computed tomography (CT)-guided periarterial ethanol injection.MethodsEthanol (10 ml, 99.6 %) was injected around the right renal artery in six sheep under CT guidance with the left kidney serving as a control. Before and after the intervention, the sheep underwent MR imaging studies and the serum creatinine level was measured. One month after the intervention, the sheep were euthanized and norepinephrine (NE) concentration in the renal parenchyma was measured to evaluate the efficacy of the procedure. The treated tissues were also examined histopathologically to evaluate vascular, parenchymal, and neural injury.ResultsThe right kidney parenchymal NE concentration decreased significantly compared with the left kidney after intervention (average reduction: 40 %, P = 0.0016). Histologic examination revealed apparent denervation with no other vascular or parenchymal injuries observed in the histological and imaging studies.ConclusionEffective and feasible RSD was achieved using CT-guided periarterial ethanol injection. This technique may be a potential alternative to catheter-based RFA in the treatment of hypertension

  18. Primary nerve-sheath tumours of the trigeminal nerve: clinical and MRI findings

    International Nuclear Information System (INIS)

    Majoie, C.B.L.M.; Hulsmans, F.J.H.; Sie, L.H.; Castelijns, J.A.; Valk, J.; Walter, A.; Albrecht, K.W.

    1999-01-01

    We reviewed the clinical and MRI findings in primary nerve-sheath tumours of the trigeminal nerve. We retrospectively reviewed the medical records, imaging and histological specimens of 10 patients with 11 primary tumours of the trigeminal nerve. We assessed whether tumour site, size, morphology or signal characteristics were related to symptoms and signs or histological findings. Histological proof was available for 8 of 11 tumours: six schwannomas and two plexiform neurofibromas. The other three tumours were thought to be schwannomas, because they were present in patients with neurofibromatosis type 2 and followed the course of the trigeminal nerve. Uncommon MRI appearances were observed in three schwannomas and included a large intratumoral haemorrhage, a mainly low-signal appearance on T2-weighted images and a rim-enhancing, multicystic appearance. Only four of nine schwannomas caused trigeminal nerve symptoms, including two with large cystic components, one haemorrhagic and one solid tumor. Of the five schwannomas which did not cause any trigeminal nerve symptoms, two were large. Only one of the plexiform neurofibromas caused trigeminal nerve symptoms. Additional neurological symptoms and signs, not related to the trigeminal nerve, could be attributed to the location of the tumour in three patients. (orig.)

  19. MR imaging of benign peripheral nerve sheath tumors

    International Nuclear Information System (INIS)

    Soederlund, V.; Goeranson, H.; Bauer, H.C.F.

    1994-01-01

    In a retrospective, nonblind review of MR imaging of 15 benign peripheral nerve neoplasms in 13 patients, the signal pattern of the tumors (including contrast-enhanced images) and stage were assessed. One lesion was subcutaneous, 9 intramuscular, 2 intermuscular and 3 extracompartmental. One lesion was located to the trunk, 5 to the upper extremity and 9 to the lower. The signal on T1-weighted spin-echo images was homogeneous isointense compared to adjacent muscle in 11 lesions and in 2 slightly hyper- and in 2 slightly hypointense. T2-weighted spin-echo images, acquired in all but one examination, showed a hyperintense signal, homogeneous in 8 and centrally inhomogeneous in 6 lesions. Postcontrast T1-weighted images of 11 lesions, showed a strong signal, with an inhomogeneous enhancement in the center of the lesion similar to that obtained in T2-weighted images. In 2 cases there were signal characteristics indicating bleeding in the tumor. In one lesion both the nonenhanced and contrast-enhanced T1-weighted images showed a hypointense signal in the tumor center suggestive of intramuscular myxoma. All lesions were well delineated without reactive edema. In all cases, anatomic tumor location was correctly assessed. Although the findings were not pathognomonic for neurinoma, MR imaging provided valuable information confirming the clinical and cytologic assessments. (orig.)

  20. Nerve supply to the pelvis (image)

    Science.gov (United States)

    The nerves that branch off the central nervous system (CNS) provide messages to the muscles and organs for normal ... be compromised. In multiple sclerosis, the demyelinization of nerve cells may lead to bowel incontinence, bladder problems ...

  1. [Facial nerve neurinomas].

    Science.gov (United States)

    Sokołowski, Jacek; Bartoszewicz, Robert; Morawski, Krzysztof; Jamróz, Barbara; Niemczyk, Kazimierz

    2013-01-01

    Evaluation of diagnostic, surgical technique, treatment results facial nerve neurinomas and its comparison with literature was the main purpose of this study. Seven cases of patients (2005-2011) with facial nerve schwannomas were included to retrospective analysis in the Department of Otolaryngology, Medical University of Warsaw. All patients were assessed with history of the disease, physical examination, hearing tests, computed tomography and/or magnetic resonance imaging, electronystagmography. Cases were observed in the direction of potential complications and recurrences. Neurinoma of the facial nerve occurred in the vertical segment (n=2), facial nerve geniculum (n=1) and the internal auditory canal (n=4). The symptoms observed in patients were analyzed: facial nerve paresis (n=3), hearing loss (n=2), dizziness (n=1). Magnetic resonance imaging and computed tomography allowed to confirm the presence of the tumor and to assess its staging. Schwannoma of the facial nerve has been surgically removed using the middle fossa approach (n=5) and by antromastoidectomy (n=2). Anatomical continuity of the facial nerve was achieved in 3 cases. In the twelve months after surgery, facial nerve paresis was rated at level II-III° HB. There was no recurrence of the tumor in radiological observation. Facial nerve neurinoma is a rare tumor. Currently surgical techniques allow in most cases, the radical removing of the lesion and reconstruction of the VII nerve function. The rate of recurrence is low. A tumor of the facial nerve should be considered in the differential diagnosis of nerve VII paresis. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  2. Accelerated magnetic resonance diffusion tensor imaging of the median nerve using simultaneous multi-slice echo planar imaging with blipped CAIPIRINHA

    Energy Technology Data Exchange (ETDEWEB)

    Filli, Lukas; Kenkel, David; Boss, Andreas; Manoliu, Andrei; Andreisek, Gustav; Runge, Val M.; Guggenberger, Roman [University Hospital of Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Piccirelli, Marco [University Hospital of Zurich, Department of Neuroradiology, Zurich (Switzerland); Bhat, Himanshu [Siemens Medical Solutions USA Inc, Charlestown, MA (United States)

    2016-06-15

    To investigate the feasibility of MR diffusion tensor imaging (DTI) of the median nerve using simultaneous multi-slice echo planar imaging (EPI) with blipped CAIPIRINHA. After federal ethics board approval, MR imaging of the median nerves of eight healthy volunteers (mean age, 29.4 years; range, 25-32) was performed at 3 T using a 16-channel hand/wrist coil. An EPI sequence (b-value, 1,000 s/mm{sup 2}; 20 gradient directions) was acquired without acceleration as well as with twofold and threefold slice acceleration. Fractional anisotropy (FA), mean diffusivity (MD) and quality of nerve tractography (number of tracks, average track length, track homogeneity, anatomical accuracy) were compared between the acquisitions using multivariate ANOVA and the Kruskal-Wallis test. Acquisition time was 6:08 min for standard DTI, 3:38 min for twofold and 2:31 min for threefold acceleration. No differences were found regarding FA (standard DTI: 0.620 ± 0.058; twofold acceleration: 0.642 ± 0.058; threefold acceleration: 0.644 ± 0.061; p ≥ 0.217) and MD (standard DTI: 1.076 ± 0.080 mm{sup 2}/s; twofold acceleration: 1.016 ± 0.123 mm{sup 2}/s; threefold acceleration: 0.979 ± 0.153 mm{sup 2}/s; p ≥ 0.074). Twofold acceleration yielded similar tractography quality compared to standard DTI (p > 0.05). With threefold acceleration, however, average track length and track homogeneity decreased (p = 0.004-0.021). Accelerated DTI of the median nerve is feasible. Twofold acceleration yields similar results to standard DTI. (orig.)

  3. Normal and sonographic anatomy of selected peripheral nerves. Part II: Peripheral nerves of the upper limb

    Directory of Open Access Journals (Sweden)

    Berta Kowalska

    2012-06-01

    Full Text Available The ultrasonographic examination is frequently used for imaging peripheral nerves. It serves to supplement the physical examination, electromyography, and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive, well-tolerated by patients, and relatively inexpensive. Part I of this article series described in detail the characteristic USG picture of peripheral nerves and the proper examination technique, following the example of the median nerve. This nerve is among the most often examined peripheral nerves of the upper limb. This part presents describes the normal anatomy and ultrasound picture of the remaining large nerve branches in the upper extremity and neck – the spinal accessory nerve, the brachial plexus, the suprascapular, axillary, musculocutaneous, radial and ulnar nerves. Their normal anatomy and ultrasonographic appearance have been described, including the division into individual branches. For each of them, specific reference points have been presented, to facilitate the location of the set trunk and its further monitoring. Sites for the application of the ultrasonographic probe at each reference point have been indicated. In the case of the ulnar nerve, the dynamic component of the examination was emphasized. The text is illustrated with images of probe positioning, diagrams of the normal course of the nerves as well as a series of ultrasonographic pictures of normal nerves of the upper limb. This article aims to serve as a guide in the ultrasound examination of the peripheral nerves of the upper extremity. It should be remembered that a thorough knowledge of the area’s topographic anatomy is required for this type of examination.

  4. Visualization of isolated trigeminal nerve invasion by lymphoma using gadolinium-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Manon-Espaillat, R.; Lanska, D.J.; Ruff, R.L.; Cleveland Veteran's Administration Medical Center, OH; Case Western Reserve Univ., Cleveland, OH; Masaryk, T.; University Hospitals of Cleveland, OH; Case Western Reserve Univ., Cleveland, OH

    1990-01-01

    A 50-year-old man with active histiocytic lymphoma for 12 years developed an isolated right trigeminal neuropathy. Initial evaluation with head computed tomography, X-rays of the skull base, bone scan, and cerebrospinal fluid analysis including cytology were normal. Gadolinium-enhanced magnetic resonance imaging (MRI) showed enlargement of the proximal third of the right trigeminal nerve. Gadolinium-enhanced MRI can be useful for the early demonstration of cranial nerve invasion by lymphoma. (orig.)

  5. MR imaging of the major nerves about the elbow: cadaveric study examining the effect of flexion and extension of the elbow and pronation and supination of the forearm

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Sook; Yeh, Lee Ren; Trudell, D.; Resnick, D. [Department of Radiology (114), Veterans Administration Medical Center, San Diego, CA (United States)

    1998-08-01

    Magnetic resonance (MR) imaging provides useful information in the evaluation of peripheral nerves. Recent advances in MR imaging allow for detailed depiction of the soft tissue structures of the elbow joint. Three major nerves are present about the elbow. Six cadaveric elbows were imaged to depict the normal anatomy of these nerves and to determine the best plane and position of the elbow for optimal visualization of each nerve. Axial images of the elbow in full extension with the forearm in supination allow identification of all major nerves. Axial images with the elbow in full flexion allow accurate assessment of the cubital tunnel and the ulner nerve. Axial images of the elbow in full extension with the forearm in pronation are helpful for assessment of the median and radial nerves in the forearm. (orig.) With 11 figs., 20 refs.

  6. Trigeminal neuralgia and facial nerve paralysis

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [IPOFG, Department of Radiology, Lisbon (Portugal)

    2005-03-01

    The trigeminal nerve is the largest of the cranial nerves. It provides sensory input from the face and motor innervation to the muscles of mastication. The facial nerve is the cranial nerve with the longest extracranial course, and its main functions include motor innervation to the muscles of facial expression, sensory control of lacrimation and salivation, control of the stapedial reflex and to carry taste sensation from the anterior two-thirds of the tongue. In order to be able adequately to image and follow the course of these cranial nerves and their main branches, a detailed knowledge of neuroanatomy is required. As we are dealing with very small anatomic structures, high resolution dedicated imaging studies are required to pick up normal and pathologic nerves. Whereas CT is best suited to demonstrate bony neurovascular foramina and canals, MRI is preferred to directly visualize the nerve. It is also the single technique able to detect pathologic processes afflicting the nerve without causing considerable expansion such as is usually the case in certain inflammatory/infectious conditions, perineural spread of malignancies and in very small intrinsic tumours. Because a long course from the brainstem nuclei to the peripheral branches is seen, it is useful to subdivide the nerve in several segments and then tailor the imaging modality and the imaging study to that specific segment. This is particularly true in cases where topographic diagnosis can be used to locate a lesion in the course of these nerves. (orig.)

  7. Trigeminal neuralgia and facial nerve paralysis

    International Nuclear Information System (INIS)

    Borges, Alexandra

    2005-01-01

    The trigeminal nerve is the largest of the cranial nerves. It provides sensory input from the face and motor innervation to the muscles of mastication. The facial nerve is the cranial nerve with the longest extracranial course, and its main functions include motor innervation to the muscles of facial expression, sensory control of lacrimation and salivation, control of the stapedial reflex and to carry taste sensation from the anterior two-thirds of the tongue. In order to be able adequately to image and follow the course of these cranial nerves and their main branches, a detailed knowledge of neuroanatomy is required. As we are dealing with very small anatomic structures, high resolution dedicated imaging studies are required to pick up normal and pathologic nerves. Whereas CT is best suited to demonstrate bony neurovascular foramina and canals, MRI is preferred to directly visualize the nerve. It is also the single technique able to detect pathologic processes afflicting the nerve without causing considerable expansion such as is usually the case in certain inflammatory/infectious conditions, perineural spread of malignancies and in very small intrinsic tumours. Because a long course from the brainstem nuclei to the peripheral branches is seen, it is useful to subdivide the nerve in several segments and then tailor the imaging modality and the imaging study to that specific segment. This is particularly true in cases where topographic diagnosis can be used to locate a lesion in the course of these nerves. (orig.)

  8. The application of fuzzy-based methods to central nerve fiber imaging

    DEFF Research Database (Denmark)

    Axer, Hubertus; Jantzen, Jan; Keyserlingk, Diedrich Graf v.

    2003-01-01

    This paper discusses the potential of fuzzy logic methods within medical imaging. Technical advances have produced imaging techniques that can visualize structures and their functions in the living human body. The interpretation of these images plays a prominent role in diagnostic and therapeutic...... decisions, so physicians must deal with a variety of image processing methods and their applications.This paper describes three different sources of medical imagery that allow the visualization of nerve fibers in the human brain: (1) an algorithm for automatic segmentation of some parts of the thalamus....... Fuzzy logic methods were applied to analyze these pictures from low- to high-level image processing. The solutions presented here are motivated by problems of routine neuroanatomic research demonstrating fuzzy-based methods to be valuable tools in medical image processing....

  9. High resolution ultrasound and magnetic resonance imaging of the optic nerve and the optic nerve sheath: anatomic correlation and clinical importance.

    Science.gov (United States)

    Steinborn, M; Fiegler, J; Kraus, V; Denne, C; Hapfelmeier, A; Wurzinger, L; Hahn, H

    2011-12-01

    We performed a cadaver study to evaluate the accuracy of measurements of the optic nerve and the optic nerve sheath for high resolution US (HRUS) and magnetic resonance imaging (MRI). Five Thiel-fixated cadaver specimens of the optic nerve were examined with HRUS and MRI. Measurements of the optic nerve and the ONSD were performed before and after the filling of the optic nerve sheath with saline solution. Statistical analysis included the calculation of the agreement of measurements and the evaluation of the intraobserver and interobserver variation. Overall a good correlation of measurement values between HRUS and MRI can be found (mean difference: 0.02-0.97 mm). The repeatability coefficient (RC) and concordance correlation coefficient (CCC) values were good to excellent for most acquisitions (RC 0.2-1.11 mm; CCC 0.684-0.949). The highest variation of measurement values was found for transbulbar sonography (RC 0.58-1.83 mm; CCC 0.615/0.608). If decisive anatomic structures are clearly depicted and the measuring points are set correctly, there is a good correlation between HRUS and MRI measurements of the optic nerve and the ONSD even on transbulbar sonography. As most of the standard and cut-off values that have been published for ultrasound are significantly lower than the results obtained with MRI, a reevaluation of sonographic ONSD measurement with correlation to MRI is necessary. © Georg Thieme Verlag KG Stuttgart · New York.

  10. AMPUTATION AND REFLEX SYMPATHETIC DYSTROPHY

    NARCIS (Netherlands)

    GEERTZEN, JHB; EISMA, WH

    Reflex sympathetic dystrophy is a chronic pain syndrome characterized by chronic burning pain, restricted range of motion, oedema and vasolability. Patients are difficult to treat and the prognosis is very often poor. This report emphasizes that an amputation in case of a reflex sympathetic

  11. Cardiac sympathetic neuronal damage precedes myocardial fibrosis in patients with Anderson-Fabry disease

    Energy Technology Data Exchange (ETDEWEB)

    Imbriaco, Massimo; Piscopo, Valentina; Ponsiglione, Andrea; Nappi, Carmela; Puglia, Marta; Dell' Aversana, Serena; Spinelli, Letizia; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Sciences, Naples (Italy); Pellegrino, Teresa [National Council of Research, Institute of Biostructure and Bioimaging, Naples (Italy); Petretta, Mario [University Federico II, Department of Translational Medical Sciences, Naples (Italy); Riccio, Eleonora; Pisani, Antonio [University of Naples Federico II, Department of Public Health, Naples (Italy)

    2017-12-15

    Cardiac sympathetic denervation may be detectable in patients with Anderson-Fabry disease (AFD), suggesting its usefulness for early detection of the disease. However, the relationship between sympathetic neuronal damage measured by {sup 123}I-metaiodobenzylguanidine (MIBG) imaging with myocardial fibrosis on cardiac magnetic resonance (CMR) is still unclear. Cardiac sympathetic innervation was assessed by {sup 123}I-MIBG single-photon emission computed tomography (SPECT) in 25 patients with genetically proved AFD. Within one month from MIBG imaging, all patients underwent contrast-enhanced CMR. MIBG defect size and fibrosis size on CMR were measured for the left ventricle (LV) and expressed as %LV. Patients were divided into three groups according to MIBG and CMR findings: (1) matched normal, without MIBG defects and without fibrosis on CMR (n = 10); (2) unmatched, with MIBG defect but without fibrosis (n = 5); and (3) matched abnormal, with MIBG defect and fibrosis (n = 10). The three groups did not differ with respect to age, gender, α-galactosidase, proteinuria, glomerular filtration rate, and troponin I, while New York Heart Association class (p = 0.008), LV hypertrophy (p = 0.05), and enzyme replacement therapy (p = 0.02) were different among groups. Although in patients with matched abnormal findings, there was a significant correlation between MIBG defect size and area of fibrosis at CMR (r{sup 2} = 0.98, p < 0.001), MIBG defect size was larger than fibrosis size (26 ± 23 vs. 18 ± 13%LV, p = 0.02). Sympathetic neuronal damage is frequent in AFD patients, and it may precede myocardial damage, such as fibrosis. Thus, {sup 123}I-MIBG imaging can be considered a challenging technique for early detection of cardiac involvement in AFD. (orig.)

  12. Molecular Mechanisms Underlying β-Adrenergic Receptor-Mediated Cross-Talk between Sympathetic Neurons and Immune Cells

    Directory of Open Access Journals (Sweden)

    Dianne Lorton

    2015-03-01

    Full Text Available Cross-talk between the sympathetic nervous system (SNS and immune system is vital for health and well-being. Infection, tissue injury and inflammation raise firing rates of sympathetic nerves, increasing their release of norepinephrine (NE in lymphoid organs and tissues. NE stimulation of β2-adrenergic receptors (ARs in immune cells activates the cAMP-protein kinase A (PKA intracellular signaling pathway, a pathway that interfaces with other signaling pathways that regulate proliferation, differentiation, maturation and effector functions in immune cells. Immune–SNS cross-talk is required to maintain homeostasis under normal conditions, to develop an immune response of appropriate magnitude after injury or immune challenge, and subsequently restore homeostasis. Typically, β2-AR-induced cAMP is immunosuppressive. However, many studies report actions of β2-AR stimulation in immune cells that are inconsistent with typical cAMP–PKA signal transduction. Research during the last decade in non-immune organs, has unveiled novel alternative signaling mechanisms induced by β2-AR activation, such as a signaling switch from cAMP–PKA to mitogen-activated protein kinase (MAPK pathways. If alternative signaling occurs in immune cells, it may explain inconsistent findings of sympathetic regulation of immune function. Here, we review β2-AR signaling, assess the available evidence for alternative signaling in immune cells, and provide insight into the circumstances necessary for “signal switching” in immune cells.

  13. Iodine and freeze-drying enhanced high-resolution MicroCT imaging for reconstructing 3D intraneural topography of human peripheral nerve fascicles.

    Science.gov (United States)

    Yan, Liwei; Guo, Yongze; Qi, Jian; Zhu, Qingtang; Gu, Liqiang; Zheng, Canbin; Lin, Tao; Lu, Yutong; Zeng, Zitao; Yu, Sha; Zhu, Shuang; Zhou, Xiang; Zhang, Xi; Du, Yunfei; Yao, Zhi; Lu, Yao; Liu, Xiaolin

    2017-08-01

    The precise annotation and accurate identification of the topography of fascicles to the end organs are prerequisites for studying human peripheral nerves. In this study, we present a feasible imaging method that acquires 3D high-resolution (HR) topography of peripheral nerve fascicles using an iodine and freeze-drying (IFD) micro-computed tomography (microCT) method to greatly increase the contrast of fascicle images. The enhanced microCT imaging method can facilitate the reconstruction of high-contrast HR fascicle images, fascicle segmentation and extraction, feature analysis, and the tracing of fascicle topography to end organs, which define fascicle functions. The complex intraneural aggregation and distribution of fascicles is typically assessed using histological techniques or MR imaging to acquire coarse axial three-dimensional (3D) maps. However, the disadvantages of histological techniques (static, axial manual registration, and data instability) and MR imaging (low-resolution) limit these applications in reconstructing the topography of nerve fascicles. Thus, enhanced microCT is a new technique for acquiring 3D intraneural topography of the human peripheral nerve fascicles both to improve our understanding of neurobiological principles and to guide accurate repair in the clinic. Additionally, 3D microstructure data can be used as a biofabrication model, which in turn can be used to fabricate scaffolds to repair long nerve gaps. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Renal nerves dynamically regulate renal blood flow in conscious, healthy rabbits.

    Science.gov (United States)

    Schiller, Alicia M; Pellegrino, Peter R; Zucker, Irving H

    2016-01-15

    Despite significant clinical interest in renal denervation as a therapy, the role of the renal nerves in the physiological regulation of renal blood flow (RBF) remains debated. We hypothesized that the renal nerves physiologically regulate beat-to-beat RBF variability (RBFV). This was tested in chronically instrumented, healthy rabbits that underwent either bilateral surgical renal denervation (DDNx) or a sham denervation procedure (INV). Artifact-free segments of RBF and arterial pressure (AP) from calmly resting, conscious rabbits were used to extract RBFV and AP variability for time-domain, frequency-domain, and nonlinear analysis. Whereas steady-state measures of RBF, AP, and heart rate did not statistically differ between groups, DDNx rabbits had greater RBFV than INV rabbits. AP-RBF transfer function analysis showed greater admittance gain in DDNx rabbits than in INV rabbits, particularly in the low-frequency (LF) range where systemic sympathetic vasomotion gives rise to AP oscillations. In the LF range, INV rabbits exhibited a negative AP-RBF phase shift and low coherence, consistent with the presence of an active control system. Neither of these features were present in the LF range of DDNx rabbits, which showed no phase shift and high coherence, consistent with a passive, Ohm's law pressure-flow relationship. Renal denervation did not significantly affect nonlinear RBFV measures of chaos, self-affinity, or complexity, nor did it significantly affect glomerular filtration rate or extracellular fluid volume. Cumulatively, these data suggest that the renal nerves mediate LF renal sympathetic vasomotion, which buffers RBF from LF AP oscillations in conscious, healthy rabbits. Copyright © 2016 the American Physiological Society.

  15. Scanning laser topography and scanning laser polarimetry: comparing both imaging methods at same distances from the optic nerve head.

    Science.gov (United States)

    Kremmer, Stephan; Keienburg, Marcus; Anastassiou, Gerasimos; Schallenberg, Maurice; Steuhl, Klaus-Peter; Selbach, J Michael

    2012-01-01

    To compare the performance of scanning laser topography (SLT) and scanning laser polarimetry (SLP) on the rim of the optic nerve head and its surrounding area and thereby to evaluate whether these imaging technologies are influenced by other factors beyond the thickness of the retinal nerve fiber layer (RNFL). A total of 154 eyes from 5 different groups were examined: young healthy subjects (YNorm), old healthy subjects (ONorm), patients with normal tension glaucoma (NTG), patients with open-angle glaucoma and early glaucomatous damage (OAGE) and patients with open-angle glaucoma and advanced glaucomatous damage (OAGA). SLT and SLP measurements were taken. Four concentric circles were superimposed on each of the images: the first one measuring at the rim of the optic nerve head (1.0 ONHD), the next measuring at 1.25 optic nerve head diameters (ONHD), at 1.5 ONHD and at 1.75 ONHD. The aligned images were analyzed using GDx/NFA software. Both methods showed peaks of RNFL thickness in the superior and inferior segments of the ONH. The maximum thickness, registered by the SLT device was at the ONH rim where the SLP device tended to measure the lowest values. SLT measurements at the ONH were influenced by other tissues besides the RNFL like blood vessels and glial tissues. SLT and SLP were most strongly correlated at distances of 1.25 and 1.5 ONHD. While both imaging technologies are valuable tools in detecting glaucoma, measurements at the ONH rim should be interpreted critically since both methods might provide misleading results. For the assessment of the retinal nerve fiber layer we would like to recommend for both imaging technologies, SLT and SLP, measurements in 1.25 and 1.5 ONHD distance of the rim of the optic nerve head.

  16. Tractography of lumbar nerve roots: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Balbi, Vincent; Budzik, Jean-Francois; Thuc, Vianney le; Cotten, Anne [Hopital Roger Salengro, Service de Radiologie et d' Imagerie musculo-squelettique, Lille Cedex (France); Duhamel, Alain [Universite de Lille 2, UDSL, Lille (France); Bera-Louville, Anne [Service de Rhumatologie, Hopital Roger Salengro, Lille (France)

    2011-06-15

    The aims of this preliminary study were to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and fibre tracking (FT) of the lumbar nerve roots, and to assess potential differences in the DTI parameters of the lumbar nerves between healthy volunteers and patients suffering from disc herniation. Nineteen patients with unilateral sciatica related to posterolateral or foraminal disc herniation and 19 healthy volunteers were enrolled in this study. DTI with tractography of the L5 or S1 nerves was performed. Mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from tractography images. FA and MD values could be obtained from DTI-FT images in all controls and patients. The mean FA value of the compressed lumbar nerve roots was significantly lower than the FA of the contralateral nerve roots (p=0.0001) and of the nerve roots of volunteers (p=0.0001). MD was significantly higher in compressed nerve roots than in the contralateral nerve root (p=0.0002) and in the nerve roots of volunteers (p=0.04). DTI with tractography of the lumbar nerves is possible. Significant changes in diffusion parameters were found in the compressed lumbar nerves. (orig.)

  17. Tractography of lumbar nerve roots: initial results

    International Nuclear Information System (INIS)

    Balbi, Vincent; Budzik, Jean-Francois; Thuc, Vianney le; Cotten, Anne; Duhamel, Alain; Bera-Louville, Anne

    2011-01-01

    The aims of this preliminary study were to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and fibre tracking (FT) of the lumbar nerve roots, and to assess potential differences in the DTI parameters of the lumbar nerves between healthy volunteers and patients suffering from disc herniation. Nineteen patients with unilateral sciatica related to posterolateral or foraminal disc herniation and 19 healthy volunteers were enrolled in this study. DTI with tractography of the L5 or S1 nerves was performed. Mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from tractography images. FA and MD values could be obtained from DTI-FT images in all controls and patients. The mean FA value of the compressed lumbar nerve roots was significantly lower than the FA of the contralateral nerve roots (p=0.0001) and of the nerve roots of volunteers (p=0.0001). MD was significantly higher in compressed nerve roots than in the contralateral nerve root (p=0.0002) and in the nerve roots of volunteers (p=0.04). DTI with tractography of the lumbar nerves is possible. Significant changes in diffusion parameters were found in the compressed lumbar nerves. (orig.)

  18. Coronal MR imaging of the normal 3rd, 4th, and 5th lumbar and 1st sacral nerve roots

    International Nuclear Information System (INIS)

    Hald, J.K.; Nakstad, P.H.; Hauglum, B.E.

    1991-01-01

    Seven healthy volunteers underwent coronal MR imaging at 1.5 tesla of the normal 3rd, 4th, and 5th lumbar, and 1st sacral nerve roots. Coronal slices, 3-mm-thick with a 0.3-mm gap between the slices were obtained (TR/TE 600/22) through the lumbar spinal canal. All the nerve roots were visible on at least one image. One can routinely expect to demonstrate the 3rd, 4th, and 5th lumbar, and 1st sacral nerve roots on T1-weighted, 3-mm-thick coronal MR scans. We found no correlation between the degree of lumbar lordosis and the lengths of the visible nerve roots. Five patients with one of the following spinal problems: anomaly, tumor, disk herniation, and failed back surgery syndrome were examined according to our protocol. In all these cases coronal MR imaging gave the correct diagnosis. (orig.)

  19. Coronal MR imaging of the normal 3rd, 4th, and 5th lumbar and 1st sacral nerve roots

    Energy Technology Data Exchange (ETDEWEB)

    Hald, J K; Nakstad, P H; Hauglum, B E [National Hospital, Oslo (Norway). Dept. of Radiology

    1991-05-01

    Seven healthy volunteers underwent coronal MR imaging at 1.5 tesla of the normal 3rd, 4th, and 5th lumbar, and 1st sacral nerve roots. Coronal slices, 3-mm-thick with a 0.3-mm gap between the slices were obtained (TR/TE 600/22) through the lumbar spinal canal. All the nerve roots were visible on at least one image. One can routinely expect to demonstrate the 3rd, 4th, and 5th lumbar, and 1st sacral nerve roots on T1-weighted, 3-mm-thick coronal MR scans. We found no correlation between the degree of lumbar lordosis and the lengths of the visible nerve roots. Five patients with one of the following spinal problems: anomaly, tumor, disk herniation, and failed back surgery syndrome were examined according to our protocol. In all these cases coronal MR imaging gave the correct diagnosis. (orig.).

  20. Renal sympathetic denervation in the treatment of resistant hypertension.

    Science.gov (United States)

    Sánchez-Álvarez, Catalina; González-Vélez, Miguel; Stilp, Erik; Ward, Charisse; Mena-Hurtado, Carlos

    2014-12-01

    Arterial hypertension (HTN) is a major health problem worldwide. Treatment-resistant hypertension (trHTN) is defined as the failure to achieve target blood pressure despite the concomitant use of maximally tolerated doses of three different antihypertensive medications, including a diuretic. trHTN is associated with considerable morbidity and mortality. Renal sympathetic denervation (RDn) is available and implemented abroad as a strategy for the treatment of trHTN and is currently under clinical investigation in the United States. Selective renal sympathectomy via an endovascular approach effectively decreases renal sympathetic nerve hyperactivity leading to a decrease in blood pressure. The Symplicity catheter, currently under investigation in the United States, is a 6-French compatible system advanced under fluoroscopic guidance via percutaneous access of the common femoral artery to the distal lumen of each of the main renal arteries. Radiofrequency (RF) energy is then applied to the endoluminal surface of the renal arteries via an electrode located at the tip of the catheter. Two clinical trials (Symplicity HTN 1 and Symplicity HTN 2) have shown the efficacy of RDn with a post-procedure decline of 27/17 mmHg at 12 months and 32/12 mmHg at 6 months, respectively, with few minor adverse events. Symplicity HTN-3 study is a, multi-center, prospective, single-blind, randomized, controlled study currently under way and will provide further insights about the safety and efficacy of renal denervation in patients with trHTN.

  1. Cranial nerves III, IV and VI

    International Nuclear Information System (INIS)

    Laine, I.J.; Smoker, W.R.; Kuta, A.J.; Felton, W.L.

    1991-01-01

    Because of advances in CT and MR imaging, accurate identification and evaluation of cranial nerve lesions is now possible. Cranial nerves III, IV, and VI, providing motor and sensory control of the eye, can be evaluated as a unit. In this paper, the authors present an overview of the anatomy and pathology of these cranial nerves. We first illustrate their normal anatomic pathways from the brain stem to the orbit. This is followed by clinical examples of patients with a variety of isolated and complex palsies of these three cranial nerves. This is accomplished by inclusion of ocular photographs, correlative imaging studies, and the use of diagrams. Knowledge of the gross and imaging anatomy and the ophthalmologic manifestations of pathology affecting these three cranial nerves permits a tailored approach to their evaluation

  2. Sympathetic Nerve Hyperactivity in the Spleen: Causal for Nonpathogenic-Driven Chronic Immune-Mediated Inflammatory Diseases (IMIDs?

    Directory of Open Access Journals (Sweden)

    Denise L. Bellinger

    2018-04-01

    Full Text Available Immune-Mediated Inflammatory Diseases (IMIDs is a descriptive term coined for an eclectic group of diseases or conditions that share common inflammatory pathways, and for which there is no definitive etiology. IMIDs affect the elderly most severely, with many older individuals having two or more IMIDs. These diseases include, but are not limited to, type-1 diabetes, obesity, hypertension, chronic pulmonary disease, coronary heart disease, inflammatory bowel disease, and autoimmunity, such as rheumatoid arthritis (RA, Sjőgren’s syndrome, systemic lupus erythematosus, psoriasis, psoriatic arthritis, and multiple sclerosis. These diseases are ostensibly unrelated mechanistically, but increase in frequency with age and share chronic systemic inflammation, implicating major roles for the spleen. Chronic systemic and regional inflammation underlies the disease manifestations of IMIDs. Regional inflammation and immune dysfunction promotes targeted end organ tissue damage, whereas systemic inflammation increases morbidity and mortality by affecting multiple organ systems. Chronic inflammation and skewed dysregulated cell-mediated immune responses drive many of these age-related medical disorders. IMIDs are commonly autoimmune-mediated or suspected to be autoimmune diseases. Another shared feature is dysregulation of the autonomic nervous system and hypothalamic pituitary adrenal (HPA axis. Here, we focus on dysautonomia. In many IMIDs, dysautonomia manifests as an imbalance in activity/reactivity of the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS. These major autonomic pathways are essential for allostasis of the immune system, and regulating inflammatory processes and innate and adaptive immunity. Pathology in ANS is a hallmark and causal feature of all IMIDs. Chronic systemic inflammation comorbid with stress pathway dysregulation implicate neural-immune cross-talk in the etiology and pathophysiology of IMIDs

  3. Clinical significance of nerve root enhancement in contrast-enhanced MR imaging of the postoperative lumbar spine

    International Nuclear Information System (INIS)

    Lee, Yeon Soo; Lee, Eun Ja; Kang, Si Won; Choi, Eun Seok; Song, Chang June; Kim, Jong Chul

    2001-01-01

    To determine the significance of nerve root contrast enhancement in patients with residual or recurrent symptomatic postoperative lumbar spine. Eighty-eight patients with 116 postoperative lumbar disc lesions causing radiating back pain underwent enhanced MR imaging. Intradural nerve root enhancement was quantified by pixel measurement, and affected nerve roots were compared before and after contrast administration. Extradural nerve root enhancement was assessed visually, and nerve root enhancement and clinical symptoms were correlated. Associated lesions such as recurrent disc herniation, scar tissue, nerve root thickening and nerve root displacement were also evaluated. Of 26 cases (22.4%) involving intradural nerve root enhancement, 22 (84.6%) showed significant clinical symptoms (p=0.002). and of 59 (50.9%) demonstrating extradural enhancement, clinical symptoms showed significant correlation in 47 (79.7%) (p=0.001). Nerve root enhancement, including eleven cases where this was both intra-and extradural, showed highly significant association with clinical symptoms in 74 of the 116 cases (63.8%) (p=0.000). Among 33 cases (28.4%) of recurrent disc herniation, nerve root enhancement was observed in 28 (84.8%) and in 24 of these 28 (85.7%), significant correlation with clinical symptoms was observed (p=0.000). Where epidural fibrosis was present, correlation between nerve root enhancement and clinical symptoms was not significant (p>0.05). Nerve root thickening and displaced nerve root were, however, significantly associated with symptoms (87.2% and 88.6%, respectively). In patients with postoperative lumbar spine, the association between nerve root enhancement revealed by MRI and clinical symptoms was highly significant

  4. Differences in autonomic nerve function in patients with silent and symptomatic myocardial ischaemia.

    Science.gov (United States)

    Shakespeare, C. F.; Katritsis, D.; Crowther, A.; Cooper, I. C.; Coltart, J. D.; Webb-Peploe, M. W.

    1994-01-01

    BACKGROUND--Autonomic neuropathy provides a mechanism for the absence of symptoms in silent myocardial ischaemia, but characterisation of the type of neuropathy is lacking. AIM--To characterise and compare autonomic nerve function in patients with silent and symptomatic myocardial ischaemia. METHODS AND RESULTS--The Valsalva manoeuvre, heart rate variation (HRV) in response to deep breathing and standing, lower body negative pressure, isometric handgrip, and the cold pressor test were performed by patients with silent (n = 25) and symptomatic (n = 25) ambulatory ischaemia and by controls (n = 21). No difference in parasympathetic efferent function between patients with silent and symptomatic ischaemia was recorded, but both had significantly less HRV in response to standing than the controls (p < 0.005 for silent and p < 0.01 for symptomatic). Patients with silent ischaemia showed an increased propensity for peripheral vasodilatation compared with symptomatic patients (p < 0.02) and controls (p < 0.04). Impaired sympathetic function was found in patients with pure silent ischaemia (n = 4) compared with the remaining patients with silent ischaemia whose pain pathways were presumed to be intact. CONCLUSIONS--Patients with silent ischaemia and pain pathways presumed to be intact have an enhanced peripheral vasodilator response, and if this applied to the coronary vasculature it could provide a mechanism for limiting ischaemia to below the pain threshold. Patients with pure silent ischaemia have evidence of sympathetic autonomic dysfunction. Images PMID:8297687

  5. Tumors of peripheral nerves

    International Nuclear Information System (INIS)

    Ho, Michael; Lutz, Amelie M.

    2017-01-01

    Differentiation between malignant and benign tumors of peripheral nerves in the early stages is challenging; however, due to the unfavorable prognosis of malignant tumors early identification is required. To show the possibilities for detection, differential diagnosis and clinical management of peripheral nerve tumors by imaging appearance in magnetic resonance (MR) neurography. Review of current literature available in PubMed and MEDLINE, supplemented by the authors' own observations in clinical practice. Although not pathognomonic, several imaging features have been reported for a differentiation between distinct peripheral nerve tumors. The use of MR neurography enables detection and initial differential diagnosis in tumors of peripheral nerves. Furthermore, it plays an important role in clinical follow-up, targeted biopsy and surgical planning. (orig.) [de

  6. Sympathetic nervous dysregulation in the absence of systolic left ventricular dysfunction in a rat model of insulin resistance with hyperglycemia

    Directory of Open Access Journals (Sweden)

    Suuronen Erik J

    2011-08-01

    Full Text Available Abstract Background Diabetes mellitus is strongly associated with cardiovascular dysfunction, derived in part from impairment of sympathetic nervous system signaling. Glucose, insulin, and non-esterified fatty acids are potent stimulants of sympathetic activity and norepinephrine (NE release. We hypothesized that sustained hyperglycemia in the high fat diet-fed streptozotocin (STZ rat model of sustained hyperglycemia with insulin resistance would exhibit progressive sympathetic nervous dysfunction in parallel with deteriorating myocardial systolic and/or diastolic function. Methods Cardiac sympathetic nervous integrity was investigated in vivo via biodistribution of the positron emission tomography radiotracer and NE analogue [11C]meta-hydroxyephedrine ([11C]HED. Cardiac systolic and diastolic function was evaluated by echocardiography. Plasma and cardiac NE levels and NE reuptake transporter (NET expression were evaluated as correlative measurements. Results The animal model displays insulin resistance, sustained hyperglycemia, and progressive hypoinsulinemia. After 8 weeks of persistent hyperglycemia, there was a significant 13-25% reduction in [11C]HED retention in myocardium of STZ-treated hyperglycemic but not euglycemic rats as compared to controls. There was a parallel 17% reduction in immunoblot density for NE reuptake transporter, a 1.2 fold and 2.5 fold elevation of cardiac and plasma NE respectively, and no change in sympathetic nerve density. No change in ejection fraction or fractional area change was detected by echocardiography. Reduced heart rate, prolonged mitral valve deceleration time, and elevated transmitral early to atrial flow velocity ratio measured by pulse-wave Doppler in hyperglycemic rats suggest diastolic impairment of the left ventricle. Conclusions Taken together, these data suggest that sustained hyperglycemia is associated with elevated myocardial NE content and dysregulation of sympathetic nervous system

  7. 3 T MR 3D fast imaging employing steady state acquisition demonstrating branches of intraparotid facial nerve, parotid duct, and relation with parotid tumors

    International Nuclear Information System (INIS)

    Li Yan; Li Chuanting; Zhang Dongsheng; Ai Bin; Zhang Weidong; Wu Lebin

    2010-01-01

    Objective: To investigate the usefulness of 3 T MRI 3D-FIESTA in the evaluation of the intraparotid components of the facial nerve and parotid duct, and compare them with surgical findings. Methods: Twenty-two cases with parotid benign tumors were scanned with conventional and 3D-FIESTA sequences on 3 T MRI scanner. Postprocessed multiplanar images were obtained with the workstation. Parotid ducts and facial nerves and tumors were identified on these images. The relationship of the tumors to the facial nerves and Parotid ducts was confirmed at surgery. Results: Various types of parotid benign tumors had their characteristics on 3 T MR imaging. Parotid benign tumors mainly showed hypo-intensity on T 1 WI in 21 cases, and hyper-intensity on T 2 WI in 22 cases. But on 3D-FIESTA images, they appeared hypointensity (10 cases) or high intensity (12 cases) due to different types. Facial nerves in parotid appeared as linear structures with hypo-inteusity. The indication of the main trunks were 16 and 18 cases for T 1 WI and T 2 WI images, while on 3D-FIESTA images, the main trunks and cervicofacial and temporofacial divisions of the facial nerves were found in 22, 21,22 cases. Parotid ducts appeared as structures with hypo-intensity on T 1 WI and hyper-intensity on multiplanar images (14, 20, 22 cases). Compared with surgical results, the main trunks of the facial nerve were correctly showed by 3D-FIESTA images in 20 cases. However, in 2 cases they were not located in the operation because of shifting. Conclusion: 3 T MR 3D-FIESTA imaging could depict the extracranial facial nerve and the parotid duct in the parotid gland, which is useful for preoperative evaluation of parotid gland tumors. (authors)

  8. Retinal nerve fiber layer thickness map determined from optical coherence tomography images

    NARCIS (Netherlands)

    Mujat, M.; Chan, R. C.; Cense, B.; Park, B.H.; Joo, C.; Akkin, T.; Chen, TC; de Boer, JF

    2005-01-01

    We introduce a method to determine the retinal nerve fiber layer (RNFL) thickness in OCT images based on anisotropic noise suppression and deformable splines. Spectral-Domain Optical Coherence Tomography (SDOCT) data was acquired at 29 kHz A-line rate with a depth resolution of 2.6 mum and a depth

  9. The enlargement of geniculate fossa of facial nerve canal: a new CT finding of facial nerve canal fracture

    International Nuclear Information System (INIS)

    Gong Ruozhen; Li Yuhua; Gong Wuxian; Wu Lebin

    2006-01-01

    Objective: To discuss the value of enlargement of geniculate fossa of facial nerve canal in the diagnosis of facial nerve canal fracture. Methods: Thirty patients with facial nerve canal fracture underwent axial and coronal CT scan. The correlation between the fracture and the enlargement of geniculate fossa of facial nerve canal was analyzed. The ability of showing the fracture and enlargement of geniculate fossa of facial nerve canal in axial and coronal imaging were compared. Results: Fracture of geniculate fossa of facial nerve canal was found in the operation in 30 patients, while the fracture was detected in CT in 18 patients. Enlargement of geniculate ganglion of facial nerve was detected in 30 patients in the operation, while the enlargement of fossa was found in CT in 28 cases. Enlargement and fracture of geniculate fossa of facial nerve canal were both detected in CT images in 18 patients. Only the enlargement of geniculate fossa of facial nerve canal was shown in 12 patients in CT. Conclusion: Enlargement of geniculate fossa of facial nerve canal was a useful finding in the diagnosis of fracture of geniculate fossa in patients with facial paralysis, even no fracture line was shown on CT images. (authors)

  10. ImagePAD, a novel counting application for the Apple iPad, used to quantify axons in the mouse optic nerve.

    Science.gov (United States)

    Templeton, Justin P; Struebing, Felix L; Lemmon, Andrew; Geisert, Eldon E

    2014-11-01

    The present article introduces a new and easy to use counting application for the Apple iPad. The application "ImagePAD" takes advantage of the advanced user interface features offered by the Apple iOS platform, simplifying the rather tedious task of quantifying features in anatomical studies. For example, the image under analysis can be easily panned and zoomed using iOS-supported multi-touch gestures without losing the spatial context of the counting task, which is extremely important for ensuring count accuracy. This application allows one to quantify up to 5 different types of objects in a single field and output the data in a tab-delimited format for subsequent analysis. We describe two examples of the use of the application: quantifying axons in the optic nerve of the C57BL/6J mouse and determining the percentage of cells labeled with NeuN or ChAT in the retinal ganglion cell layer. For the optic nerve, contiguous images at 60× magnification were taken and transferred onto an Apple iPad. Axons were counted by tapping on the touch-sensitive screen using ImagePAD. Nine optic nerves were sampled and the number of axons in the nerves ranged from 38,872 axons to 50,196 axons with an average of 44,846 axons per nerve (SD = 3980 axons). Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Assessment of Optic Nerve Impairment in Patients with Neuromyelitis Optica by MR Diffusion Tensor Imaging.

    Directory of Open Access Journals (Sweden)

    Zhiye Chen

    Full Text Available Diffusion tensor imaging (DTI has been used for the evaluation of the white matter integrity. In this study, we evaluated optic nerve impairment in patients with neuromyelitis optica (NMO using DTI.Optic nerve DTI were performed on 28 NMO patients and 38 normal controls. Fractional anisotropy (FA values were measured in the anterior, middle, and posterior parts of the intraorbital optic nerve segment. For the posterior intraorbital optic nerve, FA values of BI (0.20±0.07, MI (0.24±0.16, and NA (0.25±0.14 decreased significantly compared with that of NC (0.43±0.07 (P<0.05, and ROC analysis demonstrated that the area under the curve (AUC measurements for BI vs. NC, MI vs. NC, NA vs. NC, and NMO (including BI, MI, and NA vs. NC were 0.99, 0.93, 0.88, and 0.96, respectively. The corresponding diagnostic sensitivities of ROC analysis were 100%, 80%, 80%, and 91%; and the specificities were 93%, 97%, 91%, and 93%.Decreased FA value in the intraorbital optic nerve, especially in the posterior part of the nerve, was demonstrated as a characteristic MR feature for NMO-related optic nerve impairment.

  12. Three-dimensional-fast imaging employing steady-state acquisition and T2-weighted fast spin-echo magnetic resonance sequences on visualization of cranial nerves Ⅲ-Ⅻ

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Because of the small diameter and complex anatomic course of the cranial nerves except for the optic nerve,mgeminal nerve,facial nerve,and cochlear and vestibular nerve,other cranial nerves are difficult to be visualized in magnetic resonance imaging (MRI) scanning with conventional thickness (5-10 mm).

  13. Label-free photoacoustic microscopy of peripheral nerves

    Science.gov (United States)

    Matthews, Thomas Paul; Zhang, Chi; Yao, Da-Kang; Maslov, Konstantin; Wang, Lihong V.

    2014-01-01

    Peripheral neuropathy is a common neurological problem that affects millions of people worldwide. Diagnosis and treatment of this condition are often hindered by the difficulties in making objective, noninvasive measurements of nerve fibers. Photoacoustic microscopy (PAM) has the ability to obtain high resolution, specific images of peripheral nerves without exogenous contrast. We demonstrated the first proof-of-concept imaging of peripheral nerves using PAM. As validated by both standard histology and photoacoustic spectroscopy, the origin of photoacoustic signals is myelin, the primary source of lipids in the nerves. An extracted sciatic nerve sandwiched between two layers of chicken tissue was imaged by PAM to mimic the in vivo case. Ordered fibrous structures inside the nerve, caused by the bundles of myelin-coated axons, could be observed clearly. With further technical improvements, PAM can potentially be applied to monitor and diagnose peripheral neuropathies.

  14. Effect of heat-killed Lactobacillus brevis SBC8803 on cutaneous arterial sympathetic nerve activity, cutaneous blood flow and transepidermal water loss in rats.

    Science.gov (United States)

    Horii, Y; Kaneda, H; Fujisaki, Y; Fuyuki, R; Nakakita, Y; Shigyo, T; Nagai, K

    2014-05-01

    To evaluate the efficacy of the effects of heat-killed Lactobacillus brevis SBC8803 (HK-SBC8803) on the standard physiological markers of skin health of cutaneous arterial sympathetic nerve activity (CASNA), cutaneous blood flow and transepidermal water loss (TEWL) and to determine whether SBC8803 targets serotonin 5-HT3 receptors in rats. A set of three experiments were conducted to examine the effects of SBC8803 on CASNA, cutaneous blood flow and TEWL using Wistar and hairless rats. Two additional experiments further attempted to determine whether HK-SBC8803 was targeting the serotonin 5-HT3 receptors by pretreatment with the 5-HT3 antagonist granisetron. Administration of HK-SBC8803 in the first three experiments caused marked inhibition of CASNA and significant elevation of cutaneous blood flow under urethane anaesthesia as well as significant decrease in TEWL on the dorsal skin of conscious hairless rats. Pretreatment with granisetron decreased the effects of HK-SBC8803 on CASNA and cutaneous blood flow. These findings suggest that HK-SBC8803 reduces CASNA, increases cutaneous blood flow and decreases TEWL and that 5-HT3 receptors may be involved in CASNA and cutaneous blood flow responses. HK-SBC8803 could be a useful substance in the treatment/prevention of skin problems, specifically chapped or dry skin. © 2014 The Society for Applied Microbiology.

  15. Intracellular mechanism of action of sympathetic hepatic nerves on glucose and lactate balance in perfused rat liver

    NARCIS (Netherlands)

    Ballé, C.; Beuers, U.; ENGELHARDT, R.; JUNGERMANN, K.

    1987-01-01

    In rat liver perfused in situ stimulation of the nerve plexus around the hepatic artery and the portal vein caused an increase in glucose output and a shift from lactate uptake to output. The effects of nerve stimulation on some key enzymes, metabolites and effectors of carbohydrate metabolism were

  16. Coping with dehydration: sympathetic activation and regulation of glutamatergic transmission in the hypothalamic PVN

    Science.gov (United States)

    Bardgett, Megan E.; Chen, Qing-Hui; Guo, Qing; Calderon, Alfredo S.; Andrade, Mary Ann

    2014-01-01

    Autonomic and endocrine profiles of chronic hypertension and heart failure resemble those of acute dehydration. Importantly, all of these conditions are associated with exaggerated sympathetic nerve activity (SNA) driven by glutamatergic activation of the hypothalamic paraventricular nucleus (PVN). Here, studies sought to gain insight into mechanisms of disease by determining the role of PVN ionotropic glutamate receptors in supporting SNA and mean arterial pressure (MAP) during dehydration and by elucidating mechanisms regulating receptor activity. Blockade of PVN N-methyl-d-aspartate (NMDA) receptors reduced (P dehydrated (DH) (48 h water deprivation) rats, but had no effect in euhydrated (EH) controls. Blockade of PVN α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors had no effect in either group. NMDA in PVN caused dose-dependent increases of renal SNA and MAP in both groups, but the maximum agonist evoked response (Emax) of the renal SNA response was greater (P dehydration increases excitatory NMDA receptor tone in PVN. Reduced glial-mediated glutamate uptake was identified as a key contributing factor. Defective glutamate uptake in PVN could therefore be an important, but as yet unexplored, mechanism driving sympathetic hyperactivity in chronic cardiovascular diseases. PMID:24671240

  17. Diffusion-weighted MR neurography of the tibial nerve and the common peroneal nerve with different motion probing gradients

    International Nuclear Information System (INIS)

    Zhao Lianxin; Wang Guangbin; Liu Yubo; Wu Lebin; Bai Xue; Yang Li; Chen Weibo

    2014-01-01

    Objective: To compare the image quality of diffusion-weighted MR neurography (DW-MRN) of the tibial nerve and the common peroneal nerve prospectively using different motion probing gradients (MPGs). Methods: A total of 21 healthy volunteers underwent DW-MRN at the knee (unilateral imaging) on a 3.0 T magnetic resonance system with unidirectional MPGs. The protocol included anterior-posterior unidirectional, right-left unidirectional, three-directional and six-directional MPGs. The apparent SNR and CNR of tibial nerve and common peroneal nerve were calculated. Three-dimensional MIP images of the nerves were evaluated blindly by two radiologists using a four-point grading scale on basis of entirety depiction and the signal intensity. Significance was determined by using Friedman and paired Wilcoxon tests. Results: The SNR of tibial nerves on DW-MRN with anterior-posterior, right-left, three directional and six directional MPGs were 4.17 (2.70-5.65), 4.35 (0.47-4.69), 3.46 (2.27-4.62) and 3.30 (2.06-4.43), respectively. CNR were 0.61 (0.46-0.70), 0.63 (0.36-0.73), 0.55 (0.39-0.64) and 0.53(0.35-0.63), respectively. The scores of tibial nerve image quality were 4.0 (2.0-4.0), 4.0 (3.0-4.0), 2.5 (2.0-3.5), 2.0 (1.0-2.5), respectively. Interobserver agreement was good and the Kappa value was 0.69 (P<0.05). The SNR of the common peroneal nerves on DW-MRN with anterior-posterior, right-left, three directional and six directional MPGs were 3.05 (2.30-4.20), 3.05 (2.26-4.34), 2.72 (1.84-13.80) and 2.68 (1.87-3.67), respectively. CNR were 0.51 (0.39-0.62), 0.51 (0.39-0.63), 0.46(0.30-0.86) and 0.46 (0.30-0.57), respectively. The scores of the common peroneal nerve image quality were 3.5 (2.0-4.0), 4.0 (2.0-4.0), 2.0 (1.0-3.0) and 2.0 (1.0-2.5), respectively. Interobserver agreement was good and the Kappa value was 0.70 (P<0.05). For SNR, CNR and nerve image quality of the tibial nerves and the common peroneal nerves, there were significant differences among different MPGs (

  18. The sympathetic nervous system is controlled by transient receptor potential vanilloid 1 in the regulation of body temperature

    Science.gov (United States)

    Alawi, Khadija M.; Aubdool, Aisah A.; Liang, Lihuan; Wilde, Elena; Vepa, Abhinav; Psefteli, Maria-Paraskevi; Brain, Susan D.; Keeble, Julie E.

    2015-01-01

    Transient receptor potential vanilloid 1 (TRPV1) is involved in sensory nerve nociceptive signaling. Recently, it has been discovered that TRPV1 receptors also regulate basal body temperature in multiple species from mice to humans. In the present study, we investigated whether TRPV1 modulates basal sympathetic nervous system (SNS) activity. C57BL6/J wild-type (WT) mice and TRPV1 knockout (KO) mice were implanted with radiotelemetry probes for measurement of core body temperature. AMG9810 (50 mg/kg) or vehicle (2% DMSO/5% Tween 80/10 ml/kg saline) was injected intraperitoneally. Adrenoceptor antagonists or vehicle (5 ml/kg saline) was injected subcutaneously. In WT mice, the TRPV1 antagonist, AMG9810, caused significant hyperthermia, associated with increased noradrenaline concentrations in brown adipose tissue. The hyperthermia was significantly attenuated by the β-adrenoceptor antagonist propranolol, the mixed α-/β-adrenoceptor antagonist labetalol, and the α1-adrenoceptor antagonist prazosin. TRPV1 KO mice have a normal basal body temperature, indicative of developmental compensation. d-Amphetamine (potent sympathomimetic) caused hyperthermia in WT mice, which was reduced in TRPV1 KO mice, suggesting a decreased sympathetic drive in KOs. This study provides new evidence that TRPV1 controls thermoregulation upstream of the SNS, providing a potential therapeutic target for sympathetic hyperactivity thermoregulatory disorders.—Alawi, K. M., Aubdool, A. A., Liang, L., Wilde, E., Vepa, A., Psefteli, M.-P., Brain, S. D., Keeble, J. E. The sympathetic nervous system is controlled by transient receptor potential vanilloid 1 in the regulation of body temperature. PMID:26136480

  19. MR imaging and T2 measurements in peripheral nerve repair with activation of Toll-like receptor 4 of neurotmesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiang; Zhang, Fang; Lu, Liejing; Li, Haojiang; Wen, Xuehua; Shen, Jun [Sun Yat-Sen University, Department of Radiology, Sun Yat-Sen Memorial Hospital, Guangzhou, Guangdong (China)

    2014-05-15

    To investigate the role of MR imaging in neurotmesis combined with surgical repair and Toll-like receptor 4 (TLR4) activation. Forty-eight rats received subepineurial microinjection of the TLR4 agonist lipopolysaccharide (LPS, n = 24) or phosphate buffered saline (PBS, n = 24) immediately after surgical repair of the transected sciatic nerve. Sequential fat-suppressed T2-weighted imaging and quantitative T2 measurements were obtained at 3, 7, 14 and 21 days after surgery, with histologic assessments performed at regular intervals. T2 relaxation times and histological quantification of the distal stumps were measured and compared. The distal stumps of transected nerves treated with LPS or PBS both showed persistent enlargement and hyperintense signal. T2 values of the distal stumps showed a rapid rise to peak level followed by a rapid decline pattern in nerves treated with LPS, while exhibiting a slow rise to peak value followed by a slow decline in nerves treated with PBS. Nerves treated with LPS exhibited more prominent macrophage recruitment, faster myelin debris clearance and more pronounced nerve regeneration. Nerves treated with TLR4 activation had a characteristic pattern of T2 value change over time. Longitudinal T2 measurements can be used to detect the enhanced repair effect associated with TLR4 activation in the surgical repair of neurotmesis. (orig.)

  20. Fibromyalgia: When Distress Becomes (Un)sympathetic Pain

    OpenAIRE

    Martinez-Lavin, Manuel

    2012-01-01

    Fibromyalgia is a painful stress-related disorder. A key issue in fibromyalgia research is to investigate how distress could be converted into pain. The sympathetic nervous system is the main element of the stress response system. In animal models, physical trauma, infection, or distressing noise can induce abnormal connections between the sympathetic nervous system and the nociceptive system. Dorsal root ganglia sodium channels facilitate this type of sympathetic pain. Similar mechanisms may...

  1. Phenotype analysis of early risk factors from electronic medical records improves image-derived diagnostic classifiers for optic nerve pathology

    Science.gov (United States)

    Chaganti, Shikha; Nabar, Kunal P.; Nelson, Katrina M.; Mawn, Louise A.; Landman, Bennett A.

    2017-03-01

    We examine imaging and electronic medical records (EMR) of 588 subjects over five major disease groups that affect optic nerve function. An objective evaluation of the role of imaging and EMR data in diagnosis of these conditions would improve understanding of these diseases and help in early intervention. We developed an automated image processing pipeline that identifies the orbital structures within the human eyes from computed tomography (CT) scans, calculates structural size, and performs volume measurements. We customized the EMR-based phenome-wide association study (PheWAS) to derive diagnostic EMR phenotypes that occur at least two years prior to the onset of the conditions of interest from a separate cohort of 28,411 ophthalmology patients. We used random forest classifiers to evaluate the predictive power of image-derived markers, EMR phenotypes, and clinical visual assessments in identifying disease cohorts from a control group of 763 patients without optic nerve disease. Image-derived markers showed more predictive power than clinical visual assessments or EMR phenotypes. However, the addition of EMR phenotypes to the imaging markers improves the classification accuracy against controls: the AUC improved from 0.67 to 0.88 for glaucoma, 0.73 to 0.78 for intrinsic optic nerve disease, 0.72 to 0.76 for optic nerve edema, 0.72 to 0.77 for orbital inflammation, and 0.81 to 0.85 for thyroid eye disease. This study illustrates the importance of diagnostic context for interpretation of image-derived markers and the proposed PheWAS technique provides a flexible approach for learning salient features of patient history and incorporating these data into traditional machine learning analyses.

  2. Size of the optic nerve in computed tomography

    International Nuclear Information System (INIS)

    Asanagi, Kaoru; Shigemori, Hiroichi; Sunabori, Shozo; Nakamura, Yasuhisa.

    1980-01-01

    Recently, the measurement of optic nerve diameter from CT images has become of great interest. For measuring the optic nerve diameter, the method of Neuro-Ocular index is advocated by Magadure, 1978. But it is very difficult to support this method, because no relationship exists between the ocular diameter and the optic nerve diameter. In order to measure the optic nerve diameter directly by CT image, we examined several Window Level and Window Width settings and print out tables. Results are as follows, 1) Width 400 and all Level settings, all optic nerves appear thick. 2) Width 100, 75, 50 and Level 0 settings show optic nerves thin. 3) Optic nerve looks thick by Width of 100, 75, 50 and Level of -50 settings. 4) By the Level set of CT value of optic nerve in each case and Width set 75 or 50, optic images show nearly the correct diameter. 5) The midpoint of CT value of optic nerve obtained from print out tables are 8 to -22 and the the average is -10. (author)

  3. Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO

    NARCIS (Netherlands)

    Vienola, Kari V.; Braaf, Boy; Sheehy, Christy K.; Yang, Qiang; Tiruveedhula, Pavan; de Boer, Johannes F.; Roorda, Austin

    2013-01-01

    Purpose To remove the eye motion and stabilize the optical frequency domain imaging (OFDI) system for obtaining high quality images of the optic nerve head (ONH) and the pore structure of the lamina cribrosa. Methods An optical coherence tomography (OCT) instrument was combined with an active eye

  4. Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sidek, S. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Medical Imaging Unit, Faculty of Medicine, Universiti Teknologi MARA, Selangor (Malaysia); Ramli, N. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Rahmat, K., E-mail: katt_xr2000@yahoo.com [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Ramli, N.M.; Abdulrahman, F. [Department of Ophthalmology, Faculty of Medicine, University Malaya, Kuala Lumpur (Malaysia); Tan, L.K. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia)

    2014-08-15

    Objectives: To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness. Methods: 3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out. Results: FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001). Conclusions: The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity.

  5. Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

    International Nuclear Information System (INIS)

    Sidek, S.; Ramli, N.; Rahmat, K.; Ramli, N.M.; Abdulrahman, F.; Tan, L.K.

    2014-01-01

    Objectives: To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness. Methods: 3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out. Results: FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001). Conclusions: The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity

  6. Stimulation of Host Bone Marrow Stromal Cells by Sympathetic Nerves Promotes Breast Cancer Bone Metastasis in Mice

    OpenAIRE

    Campbell, J. Preston; Karolak, Matthew R.; Ma, Yun; Perrien, Daniel S.; Masood-Campbell, S. Kathryn; Penner, Niki L.; Munoz, Steve A.; Zijlstra, Andries; Yang, Xiangli; Sterling, Julie A.; Elefteriou, Florent

    2012-01-01

    Bone and lung metastases are responsible for the majority of deaths in patients with breast cancer. Following treatment of the primary cancer, emotional and psychosocial factors within this population precipitate time to recurrence and death, however the underlying mechanism(s) remain unclear. Using a mouse model of bone metastasis, we provide experimental evidence that activation of the sympathetic nervous system, which is one of many pathophysiological consequences of severe stress and depr...

  7. Clinical significance of power spectral analysis of heart rate variability and {sup 123}I-metaiodobenzylguanidine (MIBG) myocardial imaging for assessing the severity of heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Yoshio; Fukuoka, Shuji; Shimotsu, Yoriko; Sasaki, Tatsuya; Kamakura, Shiro; Yasumura, Yoshio; Miyatake, Kunio; Shimomura, Katsuro [National Cardiovascular Center, Suita, Osaka (Japan); Tani, Akihiro

    1997-04-01

    The significance of power spectral analysis of heart rate variability and of MIBG myocardial imaging to see the sympathetic nervous function was evaluated in patients with congestive heart failure due to dilated cardiomyopathy. Subjects were 10 normal volunteers and 8 patients with severity NYHA II; 10 normals and 25 patients with NYHA II and III; and 17 patients treated with a beta-blocker (metoprolol 5-40 mg). ECG was recorded with a portable ECG recorder for measuring RR intervals for 24 hr, which were applied for power spectral analysis. Early and delayed imagings with 111 MBq of {sup 123}I-MIBG were performed at 15 min and 4 hr, respectively, after its intravenous administration for acquisition of anterior planar and SPECT images. Myocardial blood flow SPECT was also done with 111 MBq of {sup 201}Tl given intravenously, and difference of total defect scores between MIBG and Tl images was computed. MIBG myocardial sympathetic nerve imaging in those patients was found useful to assess the severity of heart failure, to predict the risk patients for beta-blocker treatment and to assess the risk in complicated ventricular tachycardia. (K.H.)

  8. Sympathetic reflex control of blood flow in human peripheral tissues

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human...... sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno...... skeletal muscle, cutaneous and subcutaneous tissues of the limbs indicate that the situation is more complex. Measurements have been carried out during acute as well as chronic sympathetic denervation. Spinal sympathetic reflex mechanisms have been evaluated in tetraplegic patients, where supraspinal...

  9. Ongoing myocardial damage relates to cardiac sympathetic nervous disintegrity in patients with heart failure

    International Nuclear Information System (INIS)

    Arimoto, Takanori; Takeishi, Yasuchika; Niizeki, Takeshi

    2005-01-01

    Iodine-123-metaiodobenzylguanidine ( 123 I-MIBG) has been used to assess the integrity and function of the cardiac sympathetic nervous system in patients with heart failure. Heart-type fatty acid binding protein (H-FABP) is released into the circulation when the myocardium is injured, and H-FABP has been recently used as a novel marker for the diagnosis of ongoing myocardial damage. The aim of the present study was to compare cardiac sympathetic nervous activity assessed by 123 I-MIBG imaging with serum levels of H-FABP in patients with heart failure. Fifty patients with chronic heart failure were studied. 123 I-MIBG imaging was carried out at 30 min (early) and 240 min (delayed) after the tracer injection. We measured serum levels of H-FABP using a sandwich enzyme linked immunosorbent assay. Heart to mediastinum (H/M) ratios of 123 I-MIBG decreased and washout rate increased with higher New York Heart Association (NYHA) functional class. H-FABP, norepinephrine and brain natriuretic peptide (BNP) levels increased as the severity of NYHA class advanced. Delayed H/M ratio was significantly correlated with H-FABP (r=-0.296, p=0.029) and BNP (r=-0.335, p=0.0213). Myocardial washout rate of 123 I-MIBG was also correlated with H-FABP (r=0.469, p 123 I-MIBG imaging is an appropriate approach to evaluate non-invasively not only cardiac sympathetic nervous activity, but also latent ongoing myocardial damage in the failing heart. (author)

  10. Strength training reduces arterial blood pressure but not sympathetic neural activity in young normotensive subjects

    Science.gov (United States)

    Carter, Jason R.; Ray, Chester A.; Downs, Emily M.; Cooke, William H.

    2003-01-01

    The effects of resistance training on arterial blood pressure and muscle sympathetic nerve activity (MSNA) at rest have not been established. Although endurance training is commonly recommended to lower arterial blood pressure, it is not known whether similar adaptations occur with resistance training. Therefore, we tested the hypothesis that whole body resistance training reduces arterial blood pressure at rest, with concomitant reductions in MSNA. Twelve young [21 +/- 0.3 (SE) yr] subjects underwent a program of whole body resistance training 3 days/wk for 8 wk. Resting arterial blood pressure (n = 12; automated sphygmomanometer) and MSNA (n = 8; peroneal nerve microneurography) were measured during a 5-min period of supine rest before and after exercise training. Thirteen additional young (21 +/- 0.8 yr) subjects served as controls. Resistance training significantly increased one-repetition maximum values in all trained muscle groups (P < 0.001), and it significantly decreased systolic (130 +/- 3 to 121 +/- 2 mmHg; P = 0.01), diastolic (69 +/- 3 to 61 +/- 2 mmHg; P = 0.04), and mean (89 +/- 2 to 81 +/- 2 mmHg; P = 0.01) arterial blood pressures at rest. Resistance training did not affect MSNA or heart rate. Arterial blood pressures and MSNA were unchanged, but heart rate increased after 8 wk of relative inactivity for subjects in the control group (61 +/- 2 to 67 +/- 3 beats/min; P = 0.01). These results indicate that whole body resistance exercise training might decrease the risk for development of cardiovascular disease by lowering arterial blood pressure but that reductions of pressure are not coupled to resistance exercise-induced decreases of sympathetic tone.

  11. Glutamate and GABA in vestibulo-sympathetic pathway neurons

    Directory of Open Access Journals (Sweden)

    Gay R Holstein

    2016-02-01

    Full Text Available The vestibulo-sympathetic reflex actively modulates blood pressure during changes in posture. This reflex allows humans to stand up and quadrupeds to rear or climb without a precipitous decline in cerebral perfusion. The vestibulo-sympathetic reflex pathway conveys signals from the vestibular end organs to the caudal vestibular nuclei. These cells, in turn, project to pre-sympathetic neurons in the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively. The present study assessed glutamate- and GABA-related immunofluorescence associated with central vestibular neurons of the vestibulo-sympathetic reflex pathway in rats. Retrograde FluoroGold tract tracing was used to label vestibular neurons with projections to RVLM or CVLM, and sinusoidal galvanic vestibular stimulation was employed to activate these pathways. Central vestibular neurons of the vestibulo-sympathetic reflex were identified by co-localization of FluoroGold and cFos protein, which accumulates in some vestibular neurons following galvanic stimulation. Triple-label immunofluorescence was used to co-localize glutamate- or GABA- labeling in the identified vestibulo-sympathetic reflex pathway neurons. Most activated projection neurons displayed intense glutamate immunofluorescence, suggestive of glutamatergic neurotransmission. To support this, anterograde tracer was injected into the caudal vestibular nuclei. Vestibular axons and terminals in RVLM and CVLM co-localized the anterograde tracer and vesicular glutamate transporter-2 signals. Other retrogradely-labeled cFos-positive neurons displayed intense GABA immunofluorescence. Vestibulo-sympathetic reflex pathway neurons of both phenotypes were present in the caudal medial and spinal vestibular nuclei, and projected to both RVLM and CVLM. As a group, however, triple-labeled vestibular cells with intense glutamate immunofluorescence were located more rostrally in the vestibular nuclei than the GABAergic neurons. Only the

  12. Calcium Imaging of Nerve-Mast Cell Signaling in the Human Intestine

    Directory of Open Access Journals (Sweden)

    Sabine Buhner

    2017-11-01

    Full Text Available Introduction: It is suggested that an altered microenvironment in the gut wall alters communication along a mast cell nerve axis. We aimed to record for the first time signaling between mast cells and neurons in intact human submucous preparations.Methods: We used the Ca2+ sensitive dye Fluo-4 AM to simultaneously image changes in intracellular calcium [Ca+2]i (%ΔF/F in neurons and mast cells. Data are presented as median with interquartile ranges (25/75%.Results: We recorded nerve responses in 29 samples upon selective activation of 223 mast cells by IgE receptor cross linking with the antibody mAb22E7. Mast cells responded to mAb22E7 with a median [Ca+2]i increase of 20% (11/39 peaking 90 s (64/144 after the application. Only very few neurons responded and the median percentage of responding neuronal area was 0% (0/5.9. Mast cell activation remained in the presence of the fast sodium channel blocker tetrodotoxin. Specific neuronal activation by transmural electrical field stimulation (EFS in 34 samples evoked instantaneously [Ca+2]i signals in submucous neurons. This was followed by a [Ca+2]i peak response of 8%ΔF/F (4/15 in 33% of 168 mast cells in the field of view. The mast cell response was abolished by the nerve blocker tetrododoxin, reduced by the Calcitonin Gene-Related Peptide receptor 1 antagonist BIBN-4096 and the Vasoactive Intestinal Peptide receptor antagonist PG97-269, but not by blockade of the neurokinin receptors 1–3.Conclusion: The findings revealed bidirectional signaling between mast cells and submucous neurons in human gut. In our macroscopically normal preparations a nerve to mast cell signaling was very prominent whereas a mast cell to nerve signaling was rather rare.

  13. ImagePAD, a Novel Counting Application for the Apple iPad®, Used to Quantify Axons in the Mouse Optic Nerve

    Science.gov (United States)

    Templeton, Justin P.; Struebing, Felix L.; Lemmon, Andrew; Geisert, Eldon E.

    2014-01-01

    The present article introduces a new and easy to use counting application for the Apple iPad. The application “ImagePAD” takes advantage of the advanced user interface features offered by the Apple iOS® platform, simplifying the rather tedious task of quantifying features in anatomical studies. For example, the image under analysis can be easily panned and zoomed using iOS-supported multi-touch gestures without losing the spatial context of the counting task, which is extremely important for ensuring count accuracy. This application allows one to quantify up to 5 different types of objects in a single field and output the data in a tab-delimited format for subsequent analysis. We describe two examples of the use of the application: quantifying axons in the optic nerve of the C57BL/6J mouse and determining the percentage of cells labeled with NeuN or ChAT in the retinal ganglion cell layer. For the optic nerve, contiguous images at 60× magnification were taken and transferred onto an Apple iPad®. Axons were counted by tapping on the touch-sensitive screen using ImagePAD. Nine optic nerves were sampled and the number of axons in the nerves ranged from 38872 axons to 50196 axons with an average of 44846 axons per nerve (SD = 3980 axons). PMID:25281829

  14. Cranial nerve palsies

    International Nuclear Information System (INIS)

    Ruggieri, P.; Adelizzi, J.; Modic, M.T.; Ross, J.S.; Tkach, J.; Masaryk, T.J.

    1990-01-01

    This paper evaluates the utility of multiplanar reconstructions (MPRs) of three-dimensional (3D) MR angiography data sets in the examination of patients with cranial nerve palsies. The authors hypothesis was that 3D data could be reformatted to highlight the intricate spatial relationships of vessels to adjacent neural tissues by taking advantage of the high vessel-parenchyma contrast in high-resolution 3D time-of-flight sequences. Twenty patients with cranial nerve palsies and 10 asymptomatic patients were examined with coronal T1-weighted and axial T2-weighted imaging plus a gadolinium-enhanced 3D MRA sequence (40/7/15 degrees, axial 60-mm volume, 0.9-mm isotropic resolution). Cranial nerves II-VIII were subsequently evaluated on axial and reformatted coronal and/or sagittal images

  15. Sex differences in the modulation of vasomotor sympathetic outflow during static handgrip exercise in healthy young humans

    Science.gov (United States)

    Jarvis, Sara S.; VanGundy, Tiffany B.; Galbreath, M. Melyn; Shibata, Shigeki; Okazaki, Kazunobu; Reelick, Miriam F.; Levine, Benjamin D.

    2011-01-01

    Sex differences in sympathetic neural control during static exercise in humans are few and the findings are inconsistent. We hypothesized women would have an attenuated vasomotor sympathetic response to static exercise, which would be further reduced during the high sex hormone [midluteal (ML)] vs. the low hormone phase [early follicular (EF)]. We measured heart rate (HR), blood pressure (BP), and muscle sympathetic nerve activity (MSNA) in 11 women and 10 men during a cold pressor test (CPT) and static handgrip to fatigue with 2 min of postexercise circulatory arrest (PECA). HR increased during handgrip, reached its peak at fatigue, and was comparable between sexes. BP increased during handgrip and PECA where men had larger increases from baseline. Mean ± SD MSNA burst frequency (BF) during handgrip and PECA was lower in women (EF, P < 0.05), as was ΔMSNA-BF smaller (main effect, both P < 0.01). ΔTotal activity was higher in men at fatigue (EF: 632 ± 418 vs. ML: 598 ± 342 vs. men: 1,025 ± 416 a.u./min, P < 0.001 for EF and ML vs. men) and during PECA (EF: 354 ± 321 vs. ML: 341 ± 199 vs. men: 599 ± 327 a.u./min, P < 0.05 for EF and ML vs. men). During CPT, HR and MSNA responses were similar between sexes and hormone phases, confirming that central integration and the sympathetic efferent pathway was comparable between the sexes and across hormone phases. Women demonstrated a blunted metaboreflex, unaffected by sex hormones, which may be due to differences in muscle mass or fiber type and, therefore, metabolic stimulation of group IV afferents. PMID:21508291

  16. α-Amylase as a reliable and convenient measure of sympathetic activity: don't start salivating just yet!

    Science.gov (United States)

    Bosch, Jos A; Veerman, Enno C I; de Geus, Eco J; Proctor, Gordon B

    2011-05-01

    Recent years have seen a growing interest in salivary α-amylase (sAA) as a non-invasive marker for sympathetic nervous system (SNS) activity. Saliva offers many advantages as a biomarker fluid and sAA is one of its most plentiful components. sAA is a digestive enzyme that breaks down starch, which provides a simple means of quantification by measuring its enzymatic activity. This commentary will address a number of common misconceptions and methodological issues that surround the use of sAA as a marker of SNS activity and limit its utility in biobehavioral research. The usefulness of sAA as an SNS marker is undermined by the fact that the parasympathetic nerves also play a significant role in sAA release. Local parasympathetic nerves regulate sAA activity via: (1) α-amylase release from glands that are solely or mainly parasympathetically innervated; (2) via synergistic sympathetic-parasympathetic effects on protein secretion (known as 'augmented secretion'); and (3) via effects on salivary flow rate. Regarding methodology, we discuss why it is problematic: (1) to ignore the contribution of salivary flow rate; (2) to use absorbent materials for saliva collection, and; (3) to stimulate saliva secretion by chewing. While these methodological problems can be addressed by using standardized and timed collection of unstimulated saliva, the physiological regulation of sAA secretion presents less resolvable issues. We conclude that at present there is insufficient support for the use and interpretation of sAA activity as a valid and reliable measure of SNS activity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Distortion-free diffusion tensor imaging for evaluation of lumbar nerve roots: Utility of direct coronal single-shot turbo spin-echo diffusion sequence.

    Science.gov (United States)

    Sakai, Takayuki; Doi, Kunio; Yoneyama, Masami; Watanabe, Atsuya; Miyati, Tosiaki; Yanagawa, Noriyuki

    2018-06-01

    Diffusion tensor imaging (DTI) based on a single-shot echo planer imaging (EPI-DTI) is an established method that has been used for evaluation of lumbar nerve disorders in previous studies, but EPI-DTI has problems such as a long acquisition time, due to a lot of axial slices, and geometric distortion. To solve these problems, we attempted to apply DTI based on a single-shot turbo spin echo (TSE-DTI) with direct coronal acquisition. Our purpose in this study was to investigate whether TSE-DTI may be more useful for evaluation of lumbar nerve disorders than EPI-DTI. First, lumbar nerve roots of five healthy volunteers were evaluated for optimization of imaging parameters with TSE-DTI including b-values and the number of motion proving gradient (MPG) directions. Subsequently, optimized TSE-DTI was quantitatively compared with conventional EPI-DTI by using fractional anisotropy (FA) values and visual scores in subjective visual evaluation of tractography. Lumbar nerve roots of six patients, who had unilateral neurologic symptoms in one leg, were evaluated by the optimized TSE-DTI. TSE-DTI with b-value of 400 s/mm 2 and 32 diffusion-directions could reduce the image distortion compared with EPI-DTI, and showed that the average FA values on the symptomatic side for six patients were significantly lower than those on the non-symptomatic side (P DTI might show damaged areas of lumbar nerve roots without severe image distortion. TSE-DTI might improve the reproducibility in measurements of FA values for quantification of a nerve disorder, and would become a useful tool for diagnosis of low back pain. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Synovial sarcoma mimicking benign peripheral nerve sheath tumor

    Energy Technology Data Exchange (ETDEWEB)

    Larque, Ana B.; Nielsen, G.P.; Chebib, Ivan [Massachusetts General Hospital and Harvard Medical School, Department of Pathology, Boston, MA (United States); Bredella, Miriam A. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2017-11-15

    To assess the radiographic and clinicopathologic features of synovial sarcoma of the nerve that were clinically or radiologically interpreted as benign peripheral nerve sheath tumor. Five patients with synovial sarcoma arising from the peripheral nerve and interpreted clinically and radiologically as peripheral nerve sheath tumors were identified. Clinicopathologic and imaging features were evaluated. There were three females and two males, ranging in age from 28 to 50 (mean 35.8) years. Most patients (4/5) complained of a mass, discomfort or pain. MR images demonstrated a heterogeneous, enhancing, soft tissue mass contiguous with the neurovascular bundle. On histologic examination, most tumors were monophasic synovial sarcoma (4/5). At the time of surgery, all tumors were noted to arise along or within a peripheral nerve. All patients were alive with no evidence of disease with median follow-up of 44 (range 32-237) months. For comparison, approximately 775 benign peripheral nerve sheath tumors of the extremities were identified during the same time period. Primary synovial sarcoma of the nerve can mimic peripheral nerve sheath tumors clinically and on imaging and should be included in the differential diagnosis for tumors arising from peripheral nerves. (orig.)

  19. Multimodal imaging in neurofibromatosis type 1-associated nerve sheath tumors; Multimodale Bildgebung bei Neurofibromatose-Typ-1-assoziierten Nervenscheidentumoren

    Energy Technology Data Exchange (ETDEWEB)

    Salamon, J.; Adam, G. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology; Mautner, V.F. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Neurology; Derlin, T. [Hannover Medical School, Hannover (Germany). Dept. of Nuclear Medicine

    2015-12-15

    Neurofibromatosis type 1 (NF1) is a neurogenetic disorder. Individuals with NF1 may develop a variety of benign and malignant tumors of which peripheral nerve sheath tumors represent the most frequent entity. Plexiform neurofibromas may demonstrate a locally destructive growth pattern, may cause severe symptoms and may undergo malignant transformation into malignant peripheral nerve sheath tumors (MPNSTs). Whole-body magnetic resonance imaging (MRI) represents the reference standard for detection of soft tissue tumors in NF1. It allows for identification of individuals with plexiform neurofibromas, for assessment of local tumor extent, and for evaluation of whole-body tumor burden on T2-weighted imaging. Multiparametric MRI may provide a comprehensive characterization of different tissue properties of peripheral nerve sheath tumors, and may identify parameters associated with malignant transformation. Due to the absence of any radiation exposure, whole-body MRI may be used for serial follow-up of individuals with plexiform neurofibromas. {sup 18}F-fluorodeoxyglucose positron-emission-tomography (FDG PET/CT) allows a highly sensitive and specific detection of MPNST, and should be used in case of potential malignant transformation of a peripheral nerve sheath tumor. PET/CT provides a sensitive whole-body tumor staging. The use of contrast-enhanced CT for diagnosis of peripheral nerve sheath tumors is limited to special indications. To obtain the most precise readings, optimized examination protocols and dedicated radiologists and nuclear medicine physicians familiar with the complex and variable morphologies of peripheral nerve sheath tumors are required.

  20. A multiparametric assay for quantitative nerve regeneration evaluation.

    Science.gov (United States)

    Weyn, B; van Remoortere, M; Nuydens, R; Meert, T; van de Wouwer, G

    2005-08-01

    We introduce an assay for the semi-automated quantification of nerve regeneration by image analysis. Digital images of histological sections of regenerated nerves are recorded using an automated inverted microscope and merged into high-resolution mosaic images representing the entire nerve. These are analysed by a dedicated image-processing package that computes nerve-specific features (e.g. nerve area, fibre count, myelinated area) and fibre-specific features (area, perimeter, myelin sheet thickness). The assay's performance and correlation of the automatically computed data with visually obtained data are determined on a set of 140 semithin sections from the distal part of a rat tibial nerve from four different experimental treatment groups (control, sham, sutured, cut) taken at seven different time points after surgery. Results show a high correlation between the manually and automatically derived data, and a high discriminative power towards treatment. Extra value is added by the large feature set. In conclusion, the assay is fast and offers data that currently can be obtained only by a combination of laborious and time-consuming tests.

  1. Pathology of the vestibulocochlear nerve

    Energy Technology Data Exchange (ETDEWEB)

    De Foer, Bert [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: bert.defoer@GZA.be; Kenis, Christoph [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: christophkenis@hotmail.com; Van Melkebeke, Deborah [Department of Neurology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Deborah.vanmelkebeke@Ugent.be; Vercruysse, Jean-Philippe [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: jphver@yahoo.com; Somers, Thomas [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Thomas.somers@GZA.be; Pouillon, Marc [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: marc.pouillon@GZA.be; Offeciers, Erwin [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Erwin.offeciers@GZA.be; Casselman, Jan W. [Department of Radiology, AZ Sint-Jan AV Hospital, Ruddershove 10, Bruges (Belgium); Consultant Radiologist, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium); Academic Consultent, University of Ghent (Belgium)], E-mail: jan.casselman@azbrugge.be

    2010-05-15

    There is a large scala of pathology affecting the vestibulocochlear nerve. Magnetic resonance imaging is the method of choice for the investigation of pathology of the vestibulocochlear nerve. Congenital pathology mainly consists of agenesis or hypoplasia of the vestibulocochlear nerve. Tumoral pathology affecting the vestibulocochlear nerve is most frequently located in the internal auditory canal or cerebellopontine angle. Schwannoma of the vestibulocochlear nerve is the most frequently found tumoral lesion followed by meningeoma, arachnoid cyst and epidermoid cyst. The most frequently encountered pathologies as well as some more rare entities are discussed in this chapter.

  2. Pathology of the vestibulocochlear nerve

    International Nuclear Information System (INIS)

    De Foer, Bert; Kenis, Christoph; Van Melkebeke, Deborah; Vercruysse, Jean-Philippe; Somers, Thomas; Pouillon, Marc; Offeciers, Erwin; Casselman, Jan W.

    2010-01-01

    There is a large scala of pathology affecting the vestibulocochlear nerve. Magnetic resonance imaging is the method of choice for the investigation of pathology of the vestibulocochlear nerve. Congenital pathology mainly consists of agenesis or hypoplasia of the vestibulocochlear nerve. Tumoral pathology affecting the vestibulocochlear nerve is most frequently located in the internal auditory canal or cerebellopontine angle. Schwannoma of the vestibulocochlear nerve is the most frequently found tumoral lesion followed by meningeoma, arachnoid cyst and epidermoid cyst. The most frequently encountered pathologies as well as some more rare entities are discussed in this chapter.

  3. Insulin growth factors regulate the mitotic cycle in cultured rat sympathetic neuroblasts

    International Nuclear Information System (INIS)

    DiCicco-Bloom, E.; Black, I.B.

    1988-01-01

    While neuronal mitosis is uniquely restricted to early development, the underlying regulation remains to be defined. The authors have now developed a dissociated, embryonic sympathetic neuron culture system that uses fully defined medium in which cells enter the mitotic cycle. The cultured cells expressed two neuronal traits, tyrosine hydroxylase and the neuron-specific 160-kDa neurofilament subunit protein, but were devoid of glial fibrillary acidic protein, a marker for non-myelin-forming Schwann cells in ganglia. Approximately one-third of the tyrosine hydroxylase-positive cells synthesized DNA in culture, specifically incorporating [ 3 H]thymidine into their nuclei. They used this system to define factors regulating the mitotic cycle in sympathetic neuroblasts. Members of the insulin family of growth factors, including insulin and insulin-like growth factors I and II, regulated DNA synthesis in the presumptive neuroblasts. Insulin more than doubled the proportion of tyrosine hydroxylase-positive cells entering the mitotic cycle, as indicated by autoradiography of [ 3 H]thymidine incorporation into nuclei. Scintillation spectrometry was an even more sensitive index of DNA synthesis. In contrast, the trophic protein nerve growth factor exhibited no mitogenic effect, suggesting that the mitogenic action of insulin growth factors is highly specific. The observations are discussed in the context of the detection of insulin growth factors and receptors in the developing brain

  4. RAGE mediates the inactivation of nAChRs in sympathetic neurons under high glucose conditions.

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    Chandna, Andrew R; Nair, Manoj; Chang, Christine; Pennington, Paul R; Yamamoto, Yasuhiko; Mousseau, Darrell D; Campanucci, Verónica A

    2015-02-01

    Autonomic dysfunction is a serious complication of diabetes and can lead to cardiovascular abnormalities and premature death. It was recently proposed that autonomic dysfunction is triggered by oxidation-mediated inactivation of neuronal nicotinic acetylcholine receptors (nAChRs), impairing synaptic transmission in sympathetic ganglia and resulting in autonomic failure. We investigated whether the receptor for advanced glycation end products (RAGE) and its role in the generation of reactive oxygen species (ROS) could be contributing to the events that initiate sympathetic malfunction under high glucose conditions. Using biochemical, live imaging and electrophysiological tools we demonstrated that exposure of sympathetic neurons to high glucose increases RAGE expression and oxidative markers, and that incubation with RAGE ligands (e.g. AGEs, S100 and HMGB1) mimics both ROS elevation and nAChR inactivation. In contrast, co-treatment with either antioxidants or an anti-RAGE IgG prevented the inactivation of nAChRs. Lastly, a role for RAGE in this context was corroborated by the lack of sensitivity of sympathetic neurons from RAGE knock-out mice to high glucose. These data define a pivotal role for RAGE in initiating the events associated with exposure of sympathetic neurons to high glucose, and strongly support RAGE signaling as a potential therapeutic target in the autonomic complications associated with diabetes. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  5. Characterizing Intraorbital Optic Nerve Changes on Diffusion Tensor Imaging in Thyroid Eye Disease Before Dysthyroid Optic Neuropathy.

    Science.gov (United States)

    Lee, Hwa; Lee, Young Hen; Suh, Sang-Il; Jeong, Eun-Kee; Baek, Sehyun; Seo, Hyung Suk

    The aim of this study was to determine whether the optic nerve is affected by thyroid eye disease (TED) before the development of dysthyroid optic neuropathy with diffusion-tensor imaging (DTI). Twenty TED patients and 20 controls were included. The mean, axial, and radial diffusivities and fractional anisotropy (FA) value were measured at the optic nerves in DTI. Extraocular muscle diameters were measured on computed tomography. The diffusivities and FA of the optic nerves were compared between TED and controls and between active and inactive stages of TED. The correlations between these DTI parameters and the clinical features were determined. The mean, axial, and radial diffusivities were lower in TED compared with the controls (P optic nerve before dysthyroid optic neuropathy in TED. The FA, in particular, reflected TED activity and severity.

  6. Increased intrinsic excitability of muscle vasoconstrictor preganglionic neurons may contribute to the elevated sympathetic activity in hypertensive rats.

    Science.gov (United States)

    Briant, Linford J B; Stalbovskiy, Alexey O; Nolan, Matthew F; Champneys, Alan R; Pickering, Anthony E

    2014-12-01

    Hypertension is associated with pathologically increased sympathetic drive to the vasculature. This has been attributed to increased excitatory drive to sympathetic preganglionic neurons (SPN) from brainstem cardiovascular control centers. However, there is also evidence supporting increased intrinsic excitability of SPN. To test this hypothesis, we made whole cell recordings of muscle vasoconstrictor-like (MVClike) SPN in the working-heart brainstem preparation of spontaneously hypertensive (SH) and normotensive Wistar-Kyoto (WKY) rats. The MVClike SPN have a higher spontaneous firing frequency in the SH rat (3.85 ± 0.4 vs. 2.44 ± 0.4 Hz in WKY; P = 0.011) with greater respiratory modulation of their activity. The action potentials of SH SPN had smaller, shorter afterhyperpolarizations (AHPs) and showed diminished transient rectification indicating suppression of an A-type potassium conductance (IA). We developed mathematical models of the SPN to establish if changes in their intrinsic properties in SH rats could account for their altered firing. Reduction of the maximal conductance density of IA by 15-30% changed the excitability and output of the model from the WKY to a SH profile, with increased firing frequency, amplified respiratory modulation, and smaller AHPs. This change in output is predominantly a consequence of altered synaptic integration. Consistent with these in silico predictions, we found that intrathecal 4-aminopyridine (4-AP) increased sympathetic nerve activity, elevated perfusion pressure, and augmented Traube-Hering waves. Our findings indicate that IA acts as a powerful filter on incoming synaptic drive to SPN and that its diminution in the SH rat is potentially sufficient to account for the increased sympathetic output underlying hypertension. Copyright © 2014 the American Physiological Society.

  7. Role of the renin-angiotensin system, renal sympathetic nerve system, and oxidative stress in chronic foot shock-induced hypertension in rats.

    Science.gov (United States)

    Dong, Tao; Chen, Jing-Wei; Tian, Li-Li; Wang, Lin-Hui; Jiang, Ren-Di; Zhang, Zhe; Xu, Jian-Bing; Zhao, Xiao-Dong; Zhu, Wei; Wang, Guo-Qing; Sun, Wan-Ping; Zhang, Guo-Xing

    2015-01-01

    The renin-angiotensin system (RAS) and renal sympathetic nerve system (RSNS) are involved in the development of hypertension. The present study is designed to explore the possible roles of the RAS and the RSNS in foot shock-induced hypertension. Male Sprague-Dawley rats were divided into six groups: control, foot shock, RSNS denervation, denervation plus foot shock, Captopril (angiotensin I converting enzyme inhibitor, ACE inhibitor) plus foot shock, and Tempol (superoxide dismutase mimetic) plus foot shock. Rats received foot shock for 14 days. We measured the quantity of thiobarbituric acid reactive substances (TBARS), corticosterone, renin, and angiotensin II (Ang II) in plasma, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and renal noradrenaline content. RAS component mRNA and protein levels were quantified in the cerebral cortex and hypothalamus. The two week foot shock treatment significantly increased systolic blood pressure, which was accompanied by an increase in angiotensinogen, renin, ACE1, and AT1a mRNA and protein expression in the cerebral cortex and hypothalamus, an increase of the plasma concentrations of renin, Ang II, corticosterone, and TBARS, as well as a decrease in plasma SOD and GSH-Px activities. Systolic blood pressure increase was suppressed by denervation of the RSNS or treatment with Captopril or Tempol. Interestingly, denervation or Tempol treatment both decreased main RAS components not only in the circulatory system, but also in the central nervous system. In addition, decreased antioxidant levels and increased TBARS and corticosterone levels were also partially restored by denervation or treatment with Tempol or Captopril. RAS, RSNS and oxidative stress reciprocally potentiate to play important roles in the development of foot shock-induced hypertension.

  8. Effects of 12 months continuous positive airway pressure on sympathetic activity related brainstem function and structure in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Luke Anthony Henderson

    2016-03-01

    Full Text Available Muscle sympathetic nerve activity (MSNA is greatly elevated in patients with obstructive sleep apnoea (OSA during normoxic daytime wakefulness. Increased MSNA is a precursor to hypertension and elevated cardiovascular morbidity and mortality. However, the mechanisms underlying the high MSNA in OSA are not well understood. In this study we used concurrent microneurography and magnetic resonance imaging to explore MSNA-related brainstem activity changes and anatomical changes in 15 control and 15 subjects with OSA prior to and following 6 and 12 months of continuous positive airway pressure (CPAP treatment. We found that 6 and 12 months of CPAP treatment significantly reduced the elevated resting MSNA in individuals with OSA. Furthermore, this MSNA reduction was associated with restoration of MSNA-related activity and structural changes in the medullary raphe, rostral ventrolateral medulla, dorsolateral pons and ventral midbrain. This restoration occurred after 6 months of CPAP treatment and was maintained following 12 months CPAP. These findings show that continual CPAP treatment is an effective long-term treatment for elevated MNSA likely due to its effects on restoring brainstem structure and function.

  9. Sympathetic arousal increases a negative memory bias in young women with low sex hormone levels

    Science.gov (United States)

    Nielsen, Shawn E.; Barber, Sarah J.; Chai, Audrey; Clewett, David V.; Mather, Mara

    2015-01-01

    Emotionally arousing events are typically better attended to and remembered than neutral ones. Current theories propose that arousal-induced increases in norepinephrine during encoding bias attention and memory in favor of affectively salient stimuli. Here, we tested this hypothesis by manipulating levels of physiological arousal prior to encoding and examining how it influenced memory for emotionally salient images, particularly those that are negative rather than positive in valence. We also tested whether sex steroid hormones interact with noradrenergic activity to influence these emotional memory biases in women. Healthy naturally cycling women and women on hormonal contraception completed one of the following physiological arousal manipulations prior to viewing a series of negative, positive and neutral images: 1) Immediate handgrip arousal – isometric handgrip immediately prior to encoding, 2) Residual handgrip arousal – isometric handgrip 15 min prior to encoding, or 3) No handgrip. Sympathetic arousal was measured throughout the session via pupil diameter changes. Levels of 17β-estradiol and progesterone were measured via salivary samples. Memory performance was assessed approximately 10 minutes after encoding using a surprise free recall test. The results indicated that handgrip successfully increased sympathetic arousal compared to the control task. Under immediate handgrip arousal, women showed enhanced memory for negative images over positive images; this pattern was not observed in women assigned to the residual and no-handgrip arousal conditions. Additionally, under immediate handgrip arousal, both high estradiol and progesterone levels attenuated the memory bias for negative over positive images. Follow-up hierarchical linear models revealed consistent effects when accounting for trial-by-trial variability in normative International Affective Picture System valence and arousal ratings. These findings suggest that heightened sympathetic arousal

  10. Scintigraphic assessment of cardiac sympathetic innervation with I-123-metaiodobenzylguanidine in cardiomyopathy. Special reference to cardiac arrhythmia

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Takahisa; Otsuka, Nobuaki; Sone, Teruki; Mimura, Hiroaki; Yanagimoto, Shinichi; Tomomitsu, Tatsushi; Fukunaga, Masao [Kawasaki Medical School, Kurashiki, Okayama (Japan); Morita, Koichi

    1999-07-01

    Cardiac sympathetic imagings with I-123-metaiodobenzylguanidine (MIBG) were carried out in 5 cases with dilated cardiomyopathy (DCM), 26 cases with hypertrophic cardiomyopathy (HCM), and 4 cases without cardiac disease as a control to assess cardiac sympathetic innervation qualitatively and quantitatively, and to clarify the relation of MIBG accumulation to arrhythmia. MIBG scintigraphy was performed at 15 min. (early image) and 4 hr. (delayed image) after intravenous injection of MIBG 111 MBq. The MIBG uptake ratio of mediastinum (H/M) and the cardiac washout rate (WR) from early to delayed images were calculated. On both early and delayed SPECTs, MIBG uptake was assessed by defect scores (DSs). Regarding the cases with HCM, the MIBG uptake ratio, WR, and DS were also compared in cases with and without arrhythmia. In DCM, the MIBG uptake on delayed SPECT was markedly low, the H/M ratio was significantly lower, and the DS was significantly higher than in the control (all p<0.05). As for the WR, there was no significant difference between HCM, DCM and the control. In HCM, significantly reduced MIBG uptake was observed in cases with ventricular techycardia (VT) and in cases with atrial fibrillation (Af), as compared with cases without arrhythmia (all p<0.05). There results suggest that MIBG scintigraphy might be a useful tool in the assessment of cardiac sympathetic abnormalities in cardiomyopathy, especially in cases with arrhythmia. (author)

  11. Transient facial nerve palsy after occipital nerve block: a case report.

    Science.gov (United States)

    Strauss, Lauren; Loder, Elizabeth; Rizzoli, Paul

    2014-01-01

    Occipital nerve blocks are commonly performed to treat a variety of headache syndromes and are generally believed to be safe and well tolerated. We report the case of an otherwise healthy 24-year-old woman with left side-locked occipital, parietal, and temporal pain who was diagnosed with probable occipital neuralgia. She developed complete left facial nerve palsy within minutes of blockade of the left greater and lesser occipital nerves with a solution of bupivicaine and triamcinolone. Magnetic resonance imaging of the brain with gadolinium contrast showed no abnormalities, and symptoms had completely resolved 4-5 hours later. Unintended spread of the anesthetic solution along tissue planes seems the most likely explanation for this adverse event. An aberrant course of the facial nerve or connections between the facial and occipital nerves also might have played a role, along with the patient's prone position and the use of a relatively large injection volume of a potent anesthetic. Clinicians should be aware that temporary facial nerve palsy is a possible complication of occipital nerve block. © 2014 American Headache Society.

  12. Distribution and absorption of local anesthetics in inferior alveolar nerve block: evaluation by magnetic resonance imaging.

    Science.gov (United States)

    Ay, Sinan; Küçük, Dervisşhan; Gümüş, Cesur; Kara, M Isa

    2011-11-01

    The aim of this study was to evaluate the distribution and absorption of local anesthetic solutions in inferior alveolar nerve block using magnetic resonance imaging. Forty healthy volunteers were divided into 4 groups and injected with 1.5 mL for inferior alveolar nerve block and 0.3 mL for lingual nerve block. The solutions used for the different groups were 2% lidocaine, 2% lidocaine with 0.125 mg/mL epinephrine, 4% articaine with 0.006 mg/mL epinephrine, and 4% articaine with 0.012 mg/mL epinephrine. All subjects had axial T2-weighted and fat-suppressed images at 0, 60, and 120 minutes after injection. The localization, area, and intensity (signal characteristics) of the solutions were analyzed and onset and duration times of the anesthesia were recorded. There were no significant differences between groups with regard to the intensity and area of the solutions at 0, 60, and 120 minutes after injection, but differences were found within each group. No between-group differences were found on magnetic resonance imaging in the distribution and absorption of lidocaine with or without epinephrine and articaine with 0.006 and 0.012 mg/mL epinephrine. All solutions were noticeably absorbed at 120 minutes after injection. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  13. The Influence of Prolonged Acetylsalicylic Acid Supplementation-Induced Gastritis on the Neurochemistry of the Sympathetic Neurons Supplying Prepyloric Region of the Porcine Stomach.

    Directory of Open Access Journals (Sweden)

    Katarzyna Palus

    Full Text Available This experiment was designed to establish the localization and neurochemical phenotyping of sympathetic neurons supplying prepyloric area of the porcine stomach in a physiological state and during acetylsalicylic acid (ASA induced gastritis. In order to localize the sympathetic perikarya the stomachs of both control and acetylsalicylic acid treated (ASA group animals were injected with neuronal retrograde tracer Fast Blue (FB. Seven days post FB injection, animals were divided into a control and ASA supplementation group. The ASA group was given 100 mg/kg of b.w. ASA orally for 21 days. On the 28th day all pigs were euthanized with gradual overdose of anesthetic. Then fourteen-micrometer-thick cryostat sections were processed for routine double-labeling immunofluorescence, using primary antisera directed towards tyrosine hydroxylase (TH, dopamine β-hydroxylase (DβH, neuropeptide Y (NPY, galanin (GAL, neuronal nitric oxide synthase (nNOS, leu 5-enkephalin (LENK, cocaine- and amphetamine- regulated transcript peptide (CART, calcitonin gene-related peptide (CGRP, substance P (SP and vasoactive intestinal peptide (VIP. The data obtained in this study indicate that postganglionic sympathetic nerve fibers supplying prepyloric area of the porcine stomach originate from the coeliac-cranial mesenteric ganglion complex (CCMG. In control animals, the FB-labelled neurons expressed TH (94.85 ± 1.01%, DβH (97.10 ± 0.97%, NPY (46.88 ± 2.53% and GAL (8.40 ± 0.53%. In ASA group, TH- and DβH- positive nerve cells were reduced (85.78 ± 2.65% and 88.82 ± 1.63% respectively. Moreover, ASA- induced gastritis resulted in increased expression of NPY (76.59 ± 3.02% and GAL (26.45 ± 2.75% as well as the novo-synthesis of nNOS (6.13 ± 1.11% and LENK (4.77 ± 0.42% in traced CCMG neurons. Additionally, a network of CART-, CGRP-, SP-, VIP-, LENK-, nNOS- immunoreactive (IR nerve fibers encircling the FB-positive perikarya were observed in both intact and ASA

  14. Study of the anatomical position of the femoral nerve by magnetic resonance imaging in patients with fractured neck of femur: relevance to femoral nerve block.

    LENUS (Irish Health Repository)

    Mehmood, Shehzad

    2012-01-31

    STUDY OBJECTIVE: To determine the anatomical location of the femoral nerve in patients who have sustained fracture of the neck of femur, and its relevance to femoral nerve block technique. DESIGN: Prospective, observational clinical study. SETTING: Orthopedic and Radiology departments of a regional hospital. SUBJECTS: 10 consecutive adult ASA physical status II and III patients (mean age, 78.5 yrs) and 4 adult healthy volunteers. INTERVENTIONS: A T1 magnetic resonance imaging scan was performed of both upper thighs in patients and healthy volunteers successfully. MEASUREMENTS: The distance (mm) between the midpoint of the femoral artery and the midpoint of the femoral nerve, and the distance of the femoral nerve from the skin was measured at the mid-inguinal ligament, the pubic tubercle, and at the mid-inguinal crease. Data are shown as means (SD). Differences between both sides were compared using paired Student\\'s t-tests. P < 0.05 was significant. MAIN RESULTS: In patients the mean distance (mm) between the midpoint of the femoral nerve from the midpoint of femoral artery at the mid-inguinal crease on the fractured and non-fractured sides was 10.7 and 11.0, respectively (P = 0.87). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the mid-inguinal ligament on the fractured and non-fractured sides was 9.64 and 12.5, respectively (P = 0.03). The mean distance (mm) between the midpoint of the femoral nerve from the midpoint of the femoral artery at the pubic tubercle on the fractured and non-fractured sides was 8.74 and 10.49, respectively (P = 0.18). CONCLUSIONS: Blockade of the femoral nerve may be easier to perform at the mid-inguinal crease in patients with fractured neck of femur.

  15. Sympathetic Denervation Accelerates Wound Contraction but Inhibits Reepithelialization and Pericyte Proliferation in Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Zhifang Zheng

    2017-01-01

    Full Text Available Previous studies focused on the effects of sympathetic denervation with 6-hydroxydopamine (6-OHDA on nondiabetic wounds, but the effects of 6-OHDA on diabetic wounds have not been previously reported. In this study, treated mice received intraperitoneal 6-OHDA, and control mice received intraperitoneal injections of normal saline. Full-thickness wounds were established on the backs of mice. The wounds were sectioned (four mice per group for analysis at 2, 5, 7, 10, 14, 17, and 21 days after injury. The wound areas in the control group were larger than those in the treatment group. Histological scores for epidermal and dermal regeneration were reduced in the 6-OHDA-treated group on day 21. The mast cells (MCs in each field decreased after sympathectomy on days 17 and 21. The expression levels of norepinephrine, epidermal growth factor (EGF, interleukin-1 beta, NG2 proteoglycan, and desmin in the treatment group were less than those in the control group. In conclusion, 6-OHDA delays reepithelialization during wound healing in diabetic mice by decreasing EGF, but increases wound contraction by reducing IL-1β levels and the number of MCs. Besides, 6-OHDA led to reduced pericyte proliferation in diabetic wounds, which might explain the vascular dysfunction after sympathetic nerve loss in diabetic wounds.

  16. Sympathetic neural modulation of the immune system

    International Nuclear Information System (INIS)

    Madden, K.S.

    1989-01-01

    One route by which the central nervous system communicates with lymphoid organs in the periphery is through the sympathetic nervous system (SNS). To study SNS regulation of immune activity in vivo, selective removal of peripheral noradrenergic nerve fibers was achieved by administration of the neurotoxic drug, 6-hydroxydopamine (6-OHDA), to adult mice. To assess SNS influence on lymphocyte proliferation in vitro, uptake of 125 iododeoxyuridine ( 125 IUdR), a DNA precursor, was measured following 6-OHDA treatment. Sympathectomy prior to epicutaneous immunization with TNCB did not alter draining lymph nodes (LN) cell proliferation, whereas 6-OHDA treatment before footpad immunization with KLH reduced DNA synthesis in popliteal LN by 50%. In mice which were not deliberately immunized, sympathectomy stimulated 125 IUdR uptake inguinal and axillary LN, spleen, and bone marrow. In vitro, these LN and spleen cells exhibited decreased proliferation responses to the T cell mitogen, concanavalin A (Con A), whereas lipopolysaccharide (LPS)-stimulated IgG secretion was enhanced. Studies examining 51 Cr-labeled lymphocyte trafficking to LN suggested that altered cell migration may play a part in sympathectomy-induced changes in LN cell function

  17. MR imaging of spondylolytic spondylolisthesis: changes of intervertebral foramen and nerve root compression

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hyung [Ajou Univ. College of Medicine, Seoul (Korea, Republic of); Chung, Tae Sub; Kim, Young Soo [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-08-01

    To evaluate the factors affecting intervertebral foramen stenosis and nerve root compression in spondylolytic spondylolisthesis. We investigated 120 intervertebral foramina of 60 patients with spondylolytic spondylolisthesis who had undergone lumbar MRI. A retrospective review of their MR images revealed the degree of intervertebral foramen stenosis and causes of nerve root compression. The relationship between disk height diminution following spondylolysis and degree of intervertebral foramen stenosis was also evaluated. Forty eight of 60 patients showed a similar degree of intervertebral foramen stenosis, and in 12 patients the degree of stenosis was different. In 110 intervertebral foramina, stenosis of both the superior and inferior compartments of intervertebral foramina was demonstrated. In 37 of 120 cases (30.8%), stenosis was mild ; in 44 of 120 (36.7%) it was modcrate, and in 29 of 120 (24.2%) it was severe. Stenosis of the inferior compartment was demonstrated in ten of 120 intervertebral foramina (8.3%). Nerve root compression was caused by posterior bulging of the intervertebral disk (65/120), descent of the pedicle (51/120), an isthmic bony segment above the site of spondylolytic (44/120), a bony spur formed at a spondylolytic site (11/120), and fibrocartilaginous callus at a spondylolytic site (5/48). In all cases there was degenerative change of the intervertebral disk at the affected level. There was no relationship between degree of disk height diminution and degree of intervertebral foramen stenosis (p > 0.05). The degree of intervertebral foramen stenosis and causes of nerve root compression in spondylolytic spondylolisthesis are variable, and MRI demonstrates them precisely. There was no positive relationship between degree of nerve root compression at an intervertebral foramen and degree of spondylolysis and degeneration of an intervertebral foramen. The degree of nerve root compression is believed to be another criterion for describing

  18. MR imaging of spondylolytic spondylolisthesis: changes of intervertebral foramen and nerve root compression

    International Nuclear Information System (INIS)

    Kim, Ji Hyung; Chung, Tae Sub; Kim, Young Soo

    1999-01-01

    To evaluate the factors affecting intervertebral foramen stenosis and nerve root compression in spondylolytic spondylolisthesis. We investigated 120 intervertebral foramina of 60 patients with spondylolytic spondylolisthesis who had undergone lumbar MRI. A retrospective review of their MR images revealed the degree of intervertebral foramen stenosis and causes of nerve root compression. The relationship between disk height diminution following spondylolysis and degree of intervertebral foramen stenosis was also evaluated. Forty eight of 60 patients showed a similar degree of intervertebral foramen stenosis, and in 12 patients the degree of stenosis was different. In 110 intervertebral foramina, stenosis of both the superior and inferior compartments of intervertebral foramina was demonstrated. In 37 of 120 cases (30.8%), stenosis was mild ; in 44 of 120 (36.7%) it was modcrate, and in 29 of 120 (24.2%) it was severe. Stenosis of the inferior compartment was demonstrated in ten of 120 intervertebral foramina (8.3%). Nerve root compression was caused by posterior bulging of the intervertebral disk (65/120), descent of the pedicle (51/120), an isthmic bony segment above the site of spondylolytic (44/120), a bony spur formed at a spondylolytic site (11/120), and fibrocartilaginous callus at a spondylolytic site (5/48). In all cases there was degenerative change of the intervertebral disk at the affected level. There was no relationship between degree of disk height diminution and degree of intervertebral foramen stenosis (p > 0.05). The degree of intervertebral foramen stenosis and causes of nerve root compression in spondylolytic spondylolisthesis are variable, and MRI demonstrates them precisely. There was no positive relationship between degree of nerve root compression at an intervertebral foramen and degree of spondylolysis and degeneration of an intervertebral foramen. The degree of nerve root compression is believed to be another criterion for describing

  19. Insulin resistance is associated with impaired cardiac sympathetic innervation in patients with heart failure.

    Science.gov (United States)

    Paolillo, S; Rengo, G; Pellegrino, T; Formisano, R; Pagano, G; Gargiulo, P; Savarese, G; Carotenuto, R; Petraglia, L; Rapacciuolo, A; Perrino, C; Piscitelli, S; Attena, E; Del Guercio, L; Leosco, D; Trimarco, B; Cuocolo, A; Perrone-Filardi, P

    2015-10-01

    Insulin resistance (IR) represents, at the same time, cause and consequence of heart failure (HF) and affects prognosis in HF patients, but pathophysiological mechanisms remain unclear. Hyperinsulinemia, which characterizes IR, enhances sympathetic drive, and it can be hypothesized that IR is associated with impaired cardiac sympathetic innervation in HF. Yet, this hypothesis has never been investigated. Aim of the present observational study was to assess the relationship between IR and cardiac sympathetic innervation in non-diabetic HF patients. One hundred and fifteen patients (87% males; 65 ± 11.3 years) with severe-to-moderate HF (ejection fraction 32.5 ± 9.1%) underwent iodine-123 meta-iodobenzylguanidine ((123)I-MIBG) myocardial scintigraphy to assess sympathetic innervation and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) evaluation to determine the presence of IR. From (123)I-MIBG imaging, early and late heart to mediastinum (H/M) ratios and washout rate were calculated. Seventy-two (63%) patients showed IR and 43 (37%) were non-IR. Early [1.68 (IQR 1.53-1.85) vs. 1.79 (IQR 1.66-1.95); P = 0.05] and late H/M ratio [1.50 (IQR 1.35-1.69) vs. 1.65 (IQR 1.40-1.85); P = 0.020] were significantly reduced in IR compared with non-IR patients. Early and late H/M ratio showed significant inverse correlation with fasting insulinemia and HOMA-IR. Cardiac sympathetic innervation is more impaired in patients with IR and HF compared with matched non-IR patients. These findings shed light on the relationship among IR, HF, and cardiac sympathetic nervous system. Additional studies are needed to clarify the pathogenetic relationship between IR and HF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  20. MIBG scintigraphy of the heart

    International Nuclear Information System (INIS)

    Hacker, M.; Weiss, M.

    2009-01-01

    The sympathetic nervous system plays an important role in cardiovascular physiology. Planar MIBG with or without SPECT can be used to visualize the sympathetic innervation of the heart and the abnormalities in innervation caused by, for example, ischemia, heart failure, and arrhythmogenic disorders. Furthermore, cardiac neuronal imaging allows early detection of autonomic neuropathy in diabetes mellitus. Assessment of sympathetic nerve activity in patients with heart failure has been shown to provide important prognostic information, and cardiac neuronal imaging can potentially identify patients who are at increased risk of sudden death. Moreover, therapeutic effects of different treatment strategies can be evaluated by imaging. To establish the clinical utility of cardiac neuronal imaging, it will be necessary to determine the incremental value of innervation imaging to triage heart failure patients to medical therapy, CRT (with or without ICD), or heart transplantation. (orig.)

  1. MR of acoustic neuromas; Relationship to cranial nerves

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Masayuki; Takashima, Tsutomu; Kadoya, Masumi; Takahashi, Shiroh; Miyayama, Shiroh; Taira, Sakae; Kashihara, Kengo; Yamashima, Tetsumori; Itoh, Haruhide [Kanazawa Univ. (Japan). School of Medicine

    1989-08-01

    In this report, the relationship of acoustic neuromas to the adjacent cranial nerves is discussed. On T{sub 1}-weighted images, the trigeminal nerve was detected in all 13 cases. Mild to marked compression of these nerves by the tumors was observed in eight cases. The extent of compression did not always correspond to the clinical symptoms. In four cases with a maximum tumor diameter of 2 cm or less, the 7th and 8th cranial nerves were identified. There was no facial palsy in these patients. Two patients with a tumor diameter of more than 2 cm also had no facial palsy. All patients, including those with small tumors, complained of hearing loss and/or tinnitus. While MR imaging has some limitations, it is an effective imaging modality for showing the relationship between tumors and nerves. (author).

  2. Relationship between left ventricular diastolic function and myocardial sympathetic denervation measured by {sup 123}I-meta-iodobenzylguanidine imaging in Anderson-Fabry disease

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, Letizia; Giudice, Caterina Anna; Imbriaco, Massimo; Trimarco, Bruno; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Sciences, Naples (Italy); Pellegrino, Teresa [Institute of Biostructure and Bioimaging, National Council of Research, Naples (Italy); Pisani, Antonio; Riccio, Eleonora [University Federico II, Department of Public Health, Naples (Italy); Salvatore, Marco [IRCCS SDN, Naples (Italy)

    2016-04-15

    Whether cardiac sympathetic nervous function abnormalities may be present in patients with Anderson-Fabry disease (AFD) remains unexplored. We investigated the relationship between left ventricular (LV) function and cardiac sympathetic nervous function in patients with AFD. Twenty-five patients (12 men, mean age 43 ± 13 years) with genetically proved AFD and preserved LV ejection fraction and ten age and gender-matched control subjects underwent speckle tracking echocardiography and {sup 123}I-meta-iodobenzylguanidine (MIBG) imaging from which early and late heart to mediastinum (H/M) ratios and myocardial washout rate values were calculated. In AFD patients, a significant correlation between late H/M ratio and LV mass index (r = -61, p = 0.001), left atrial volume (r = -0.72, p < 0.001), systolic pulmonary artery pressure (r = -0.75, p < 0.001), and early diastolic untwisting rate (r = -0.66, p < 0.001) was found. Ten AFD patients exhibited a late H/M ratio below two fold standard deviation of control subjects (≤1.75). Patients showing late H/M ratio ≤ 1.75 had significantly higher LV mass index, relative wall thickness, left atrial volume and systolic pulmonary artery pressure, lower systolic longitudinal strain and an early diastolic untwisting rate compared to patients with late H/M ratio > 1.75. At multivariable linear regression analysis, early diastolic untwisting rate was the only independent predictor of late H/M ratio ≤ 1.75 (odds ratio 1.15, 95 % confidence interval 1.07-1.31, p < 0.05). The present findings provide the first demonstration of a cardiac sympathetic derangement in AFD patients with preserved LV ejection fraction, which is mostly related to LV diastolic dysfunction. (orig.)

  3. Nitric Oxide Orchestrates a Power-Law Modulation of Sympathetic Firing Behaviors in Neonatal Rat Spinal Cords

    Directory of Open Access Journals (Sweden)

    Chun-Kuei Su

    2018-03-01

    Full Text Available Nitric oxide (NO is a diffusible gas and has multifarious effects on both pre- and postsynaptic events. As a consequence of complex excitatory and inhibitory integrations, NO effects on neuronal activities are heterogeneous. Using in vitro preparations of neonatal rats that retain the splanchnic sympathetic nerves and the thoracic spinal cord as an experimental model, we report here that either enhancement or attenuation of NO production in the neonatal rat spinal cords could increase, decrease, or not change the spontaneous firing behaviors recorded from splanchnic sympathetic single fibers. To elucidate the mathematical features of NO-mediated heterogeneous responses, the ratios of changes in firing were plotted against their original firing rates. In log-log plots, a linear data distribution demonstrated that NO-mediated heterogeneity in sympathetic firing responses was well described by a power function. Selective antagonists were applied to test if glycinergic, GABAergic, glutamatergic, and cholinergic neurotransmission in the spinal cord are involved in NO-mediated power-law firing modulations (plFM. NO-mediated plFM diminished in the presence of mecamylamine (an open-channel blocker of nicotinic cholinergic receptors, indicating that endogenous nicotinic receptor activities were essential for plFM. Applications of strychnine (a glycine receptor blocker, gabazine (a GABAA receptor blocker, or kynurenate (a broad-spectrum ionotropic glutamate receptor blocker also caused plFM. However, strychnine- or kynurenate-induced plFM was diminished by L-NAME (an NO synthase inhibitor pretreatments, indicating that the involvements of glycine or ionotropic glutamate receptor activities in plFM were secondary to NO signaling. To recapitulate the arithmetic natures of the plFM, the plFM were simulated by firing changes in two components: a step increment and a fractional reduction of their basal firing activities. Ionotropic glutamate receptor

  4. Relationships between the integrity and function of lumbar nerve roots as assessed by diffusion tensor imaging and neurophysiology

    Energy Technology Data Exchange (ETDEWEB)

    Chiou, S.Y.; Strutton, P.H. [Imperial College London, The Nick Davey Laboratory, Division of Surgery, Human Performance Group, Department of Surgery and Cancer, Faculty of Medicine, London (United Kingdom); Hellyer, P.J. [Imperial College London, Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, London (United Kingdom); Imperial College London, Department of Bioengineering, London (United Kingdom); Sharp, D.J. [Imperial College London, Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, London (United Kingdom); Newbould, R.D. [Imanova, Ltd, London (United Kingdom); Patel, M.C. [Charing Cross Hospital, Imaging Department, Imperial College Healthcare NHS Trust, London (United Kingdom)

    2017-09-15

    Diffusion tensor imaging (DTI) has shown promise in the measurement of peripheral nerve integrity, although the optimal way to apply the technique for the study of lumbar spinal nerves is unclear. The aims of this study are to use an improved DTI acquisition to investigate lumbar nerve root integrity and correlate this with functional measures using neurophysiology. Twenty healthy volunteers underwent 3 T DTI of the L5/S1 area. Regions of interest were applied to L5 and S1 nerve roots, and DTI metrics (fractional anisotropy, mean, axial and radial diffusivity) were derived. Neurophysiological measures were obtained from muscles innervated by L5/S1 nerves; these included the slope of motor-evoked potential input-output curves, F-wave latency, maximal motor response, and central and peripheral motor conduction times. DTI metrics were similar between the left and right sides and between vertebral levels. Conversely, significant differences in DTI measures were seen along the course of the nerves. Regression analyses revealed that DTI metrics of the L5 nerve correlated with neurophysiological measures from the muscle innervated by it. The current findings suggest that DTI has the potential to be used for assessing lumbar spinal nerve integrity and that parameters derived from DTI provide quantitative information which reflects their function. (orig.)

  5. Evaluation of phrenic nerve and diaphragm function with peripheral nerve stimulation and M-mode ultrasonography in potential pediatric phrenic nerve or diaphragm pacing candidates.

    Science.gov (United States)

    Skalsky, Andrew J; Lesser, Daniel J; McDonald, Craig M

    2015-02-01

    Assessing phrenic nerve function in the setting of diaphragmatic paralysis in diaphragm pacing candidates can be challenging. Traditional imaging modalities and electrodiagnostic evaluations are technically difficult. Either modality alone is not a direct measure of the function of the phrenic nerve and diaphragm unit. In this article, the authors present their method for evaluating phrenic nerve function and the resulting diaphragm function. Stimulating the phrenic nerve with transcutaneous stimulation and directly observing the resulting movement of the hemidiaphragm with M-mode ultrasonography provides quantitative data for predicting the success of advancing technologies such as phrenic nerve pacing and diaphragm pacing. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Cranial nerves - spectrum of inflammatory and tumorous changes

    International Nuclear Information System (INIS)

    Nemec, S.F.; Kasprian, G.; Nemec, U.; Czerny, C.

    2009-01-01

    Inflammatory processes as well as primary and secondary tumorous changes may involve cranial nerves causing neurological deficits. In addition to neurologists, ENT physicians, ophthalmologists and maxillofacial surgeons, radiologists play an important role in the investigation of patients with cranial nerve symptoms. Multidetector computed tomography (MDCT) and particularly magnetic resonance imaging (MRI) allow the depiction of the cranial nerve anatomy and pathological neural changes. This article briefly describes the imaging techniques in MDCT and MRI and is dedicated to the radiological presentation of inflammatory and tumorous cranial nerve pathologies. (orig.) [de

  7. Improved imaging of cochlear nerve hypoplasia using a 3-Tesla variable flip-angle turbo spin-echo sequence and a 7-cm surface coil.

    Science.gov (United States)

    Giesemann, Anja M; Raab, Peter; Lyutenski, Stefan; Dettmer, Sabine; Bültmann, Eva; Frömke, Cornelia; Lenarz, Thomas; Lanfermann, Heinrich; Goetz, Friedrich

    2014-03-01

    Magnetic resonance imaging of the temporal bone has an important role in decision making with regard to cochlea implantation, especially in children with cochlear nerve deficiency. The purpose of this study was to evaluate the usefulness of the combination of an advanced high-resolution T2-weighted sequence with a surface coil in a 3-Tesla magnetic resonance imaging scanner in cases of suspected cochlear nerve aplasia. Prospective study. Seven patients with cochlear nerve hypoplasia or aplasia were prospectively examined using a high-resolution three-dimensional variable flip-angle turbo spin-echo sequence using a surface coil, and the images were compared with the same sequence in standard resolution using a standard head coil. Three neuroradiologists evaluated the magnetic resonance images independently, rating the visibility of the nerves in diagnosing hypoplasia or aplasia. Eight ears in seven patients with hypoplasia or aplasia of the cochlear nerve were examined. The average age was 2.7 years (range, 9 months-5 years). Seven ears had accompanying malformations. The inter-rater reliability in diagnosing hypoplasia or aplasia was greater using the high-resolution three-dimensional variable flip-angle turbo spin-echo sequence (fixed-marginal kappa: 0.64) than with the same sequence in lower resolution (fixed-marginal kappa: 0.06). Examining cases of suspected cochlear nerve aplasia using the high-resolution three-dimensional variable flip-angle turbo spin-echo sequence in combination with a surface coil shows significant improvement over standard methods. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  8. Intraoperative Ultrasound for Peripheral Nerve Applications.

    Science.gov (United States)

    Willsey, Matthew; Wilson, Thomas J; Henning, Phillip Troy; Yang, Lynda J-S

    2017-10-01

    Offering real-time, high-resolution images via intraoperative ultrasound is advantageous for a variety of peripheral nerve applications. To highlight the advantages of ultrasound, its extraoperative uses are reviewed. The current intraoperative uses, including nerve localization, real-time evaluation of peripheral nerve tumors, and implantation of leads for peripheral nerve stimulation, are reviewed. Although intraoperative peripheral nerve localization has been performed previously using guide wires and surgical dyes, the authors' approach using ultrasound-guided instrument clamps helps guide surgical dissection to the target nerve, which could lead to more timely operations and shorter incisions. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Evaluation of cardiac sympathetic nerve activity and aldosterone suppression in patients with acute decompensated heart failure on treatment containing intravenous atrial natriuretic peptide

    International Nuclear Information System (INIS)

    Kasama, Shu; Toyama, Takuji; Kurabayashi, Masahiko; Iwasaki, Toshiya; Sumino, Hiroyuki; Kumakura, Hisao; Minami, Kazutomo; Ichikawa, Shuichi; Matsumoto, Naoya; Nakata, Tomoaki

    2014-01-01

    Aldosterone prevents the uptake of norepinephrine in the myocardium. Atrial natriuretic peptide (ANP), a circulating hormone of cardiac origin, inhibits aldosterone synthase gene expression in cultured cardiocytes. We evaluated the effects of intravenous ANP on cardiac sympathetic nerve activity (CSNA) and aldosterone suppression in patients with acute decompensated heart failure (ADHF). We studied 182 patients with moderate nonischemic ADHF requiring hospitalization and treated with standard therapy containing intravenous ANP and 10 age-matched normal control subjects. ANP was continuously infused for >96 h. In all subjects, delayed total defect score (TDS), heart to mediastinum ratio, and washout rate were determined by 123 I-metaiodobenzylguanidine (MIBG) scintigraphy. Left ventricular (LV) end-diastolic volume, end-systolic volume, and ejection fraction were determined by echocardiography. All patients with acute heart failure (AHF) were examined once within 3 days and then 4 weeks after admission, while the control subjects were examined only once (when their hemodynamics were normal). Moreover, for 62 AHF patients, plasma aldosterone concentrations were measured at admission and 1 h before stopping ANP infusion. 123 I-MIBG scintigraphic and echocardiographic parameters in normal subjects were more favorable than those in patients with AHF (all p < 0.001). After treatment, all these parameters improved significantly in AHF patients (all p < 0.001). We also found significant correlation between percent changes of TDS and aldosterone concentrations (r = 0.539, p < 0.001) in 62 AHF patients. The CSNA and LV performance were all improved in AHF patients. Furthermore, norepinephrine uptake of myocardium may be ameliorated by suppressing aldosterone production after standard treatment containing intravenous ANP. (orig.)

  10. Cardiac effects produced by long-term stimulation of thoracic autonomic ganglia or nerves: implications for interneuronal interactions within the thoracic autonomic nervous system.

    Science.gov (United States)

    Butler, C; Watson-Wright, W M; Wilkinson, M; Johnstone, D E; Armour, J A

    1988-03-01

    Electrical stimulation of an acutely decentralized stellate or middle cervical ganglion or cardiopulmonary nerve augments cardiac chronotropism or inotropism; as the stimulation continues there is a gradual reduction of this augmentation following the peak response, i.e., an inhibition of augmentation. The amount of this inhibition was found to be dependent upon the region of the heart investigated and the neural structure stimulated. The cardiac parameters which were augmented the most displayed the greatest inhibition. Maximum augmentation or inhibition occurred, in most instances, when 5-20 Hz stimuli were used. Inhibition of augmentation was overcome when the stimulation frequency was subsequently increased or following the administration of nicotine or tyramine, indicating that the inhibition was not primarily due to the lack of availability of noradrenaline in the nerve terminals of the efferent postganglionic sympathetic neurons. Furthermore, as infusions of isoproterenol or noradrenaline during the period of inhibition could still augment cardiac responses, whereas during the early peak responses they did not, the inhibition of augmentation does not appear to be due primarily to down regulation of cardiac myocyte beta-adrenergic receptors. The inhibition was modified by hexamethonium but not by phentolamine or atropine. Inhibition occurred when all ipsilateral cardiopulmonary nerves connected with acutely decentralized middle cervical and stellate ganglia were stimulated, whereas significant inhibition did not occur when these nerves were stimulated after they had been disconnected from the ipsilateral decentralized ganglia. Taken together these data indicate that the inhibition of cardiac augmentation which occurs during relatively long-term stimulation of intrathoracic sympathetic neural elements is due in large part to nicotinic cholinergic synaptic mechanisms that lie primarily in the major thoracic autonomic ganglia. They also indicate that long

  11. Increased cardiac sympathetic activity in patients with hypothyroidism as determined by iodine-123 metaiodobenzylguanidine scintigraphy

    International Nuclear Information System (INIS)

    Momose, Mitsuru; Inaba, Shigeki; Emori, Toshiaki; Imamura, Kimiharu; Kawano, Katsunori; Ueda, Tetsuro; Kobayashi, Hideki; Hosoda, Saichi

    1997-01-01

    Clinical manifestations of hypothyroidism, such as bradycardia, suggest decreased sympathetic tone. However, previous studies in patients with hypothyroidism have suggested that increased plasma noradrenaline (NA) levels represent enhanced general sympathetic activity. As yet, cardiac sympathetic activity (CSA) in hypothyroidism has not been clarified. To evaluate CSA in patients with hypothyroidism, iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy was performed in eight patients with hypothyroidism before therapy and in ten normal control patients. Planar images were obtained at 15 min and 4 h after injection of MIBG. The ratio of early myocardial uptake to the total injected dose (MU) and myocardial clearance of MIBG within 4 h p.i. (MC) were calculated. Plasma NA was also measured, and echocardiography was performed in all patients. Those patients with hypothyroidism in the euthyroid state after medical therapy were also evaluated in a similar manner. Left ventricular ejection fraction, measured by echocardiography, did not differ significantly between the groups. NA, MU and MC were significantly higher in patients with hypothyroidism than in controls, and all parameters were decreased after therapy. MC was well correlated with NA in hypothyroidism (r=0.86) before therapy. We conclude that CSA is increased in patients with hypothyroidism, in parallel with the enhanced general sympathetic activity. (orig.). With 4 figs., 2 tabs

  12. Superior Cervical Sympathetic Ganglion: Normal Imaging Appearance on 3T-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo Yeon; Lee, Jeong Hyun [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Song, Joon Seon; Song, Min Jeong [Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Hwang, Seung-Jun [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Yoon, Ra Gyoung [Department of Radiology, Catholic Kwandong University International St. Mary' s Hospital, Catholic Kwandong University College of Medicine, Incheon 22711 (Korea, Republic of); Jang, Seung Won; Park, Ji Eun [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of); Heo, Young Jin [Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan 47392 (Korea, Republic of); Choi, Young Jun; Baek, Jung Hwan [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of)

    2016-11-01

    To identify superior cervical sympathetic ganglion (SCSG) and describe their characteristic MR appearance using 3T-MRI. In this prospective study, we recruited 53 consecutive patients without history of head and neck irradiation. Using anatomic location based on literature review, both sides of the neck were evaluated to identify SCSGs in consensus. SCSGs were divided into definite (medial to internal carotid artery [ICA] and lateral to longus capitis muscle [LCM]) and probable SCSGs based on relative location to ICA and LCM. Two readers evaluated signal characteristics including intraganglionic hypointensity of all SCSGs and relative location of probable SCSGs. Interrater and intrarater agreements were quantified using unweighted kappa. Ninety-one neck sites in 53 patients were evaluated after exclusion of 15 neck sites with pathology. Definite SCSGs were identified at 66 (73%) sites, and probable SCSGs were found in 25 (27%). Probable SCSGs were located anterior to LCM in 16 (18%), lateral to ICA in 6 (7%), and posterior to ICA in 3 (3%). Intraganglionic hypointensity was identified in 82 (90%) on contrast-enhanced fat-suppressed T1-weighted images. There was no statistical difference in the relative location between definite and probable SCSGs of the right and left sides with intragnalionic hypointensity on difference pulse sequences. Interrater and intrarater agreements on the location and intraganglionic hypointensity were excellent (κ-value, 0.749–1.000). 3T-MRI identified definite SCSGs at 73% of neck sites and varied location of the remaining SCSGs. Intraganglionic hypointensity was a characteristic feature of SCSGs.

  13. Superior cervical sympathetic ganglion: Normal imaging appearance on 3T-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo Yeon; Lee, Jeong Hyun; Song, Joon Seon [Dept. of Radiology, and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); and others

    2016-09-15

    To identify superior cervical sympathetic ganglion (SCSG) and describe their characteristic MR appearance using 3T-MRI. In this prospective study, we recruited 53 consecutive patients without history of head and neck irradiation. Using anatomic location based on literature review, both sides of the neck were evaluated to identify SCSGs in consensus. SCSGs were divided into definite (medial to internal carotid artery [ICA] and lateral to longus capitis muscle [LCM]) and probable SCSGs based on relative location to ICA and LCM. Two readers evaluated signal characteristics including intraganglionic hypointensity of all SCSGs and relative location of probable SCSGs. Interrater and intrarater agreements were quantified using unweighted kappa. Ninety-one neck sites in 53 patients were evaluated after exclusion of 15 neck sites with pathology. Definite SCSGs were identified at 66 (73%) sites, and probable SCSGs were found in 25 (27%). Probable SCSGs were located anterior to LCM in 16 (18%), lateral to ICA in 6 (7%), and posterior to ICA in 3 (3%). Intraganglionic hypointensity was identified in 82 (90%) on contrast-enhanced fat-suppressed T1-weighted images. There was no statistical difference in the relative location between definite and probable SCSGs of the right and left sides with intragnalionic hypointensity on difference pulse sequences. Interrater and intrarater agreements on the location and intraganglionic hypointensity were excellent (κ-value, 0.749–1.000). 3T-MRI identified definite SCSGs at 73% of neck sites and varied location of the remaining SCSGs. Intraganglionic hypointensity was a characteristic feature of SCSGs.

  14. Optical coherence tomography of the prostate nerves

    Science.gov (United States)

    Chitchian, Shahab

    Preservation of the cavernous nerves during prostate cancer surgery is critical in preserving a man's ability to have spontaneous erections following surgery. These microscopic nerves course along the surface of the prostate within a few millimeters of the prostate capsule, and they vary in size and location from one patient to another, making preservation of the nerves difficult during dissection and removal of a cancerous prostate gland. These observations may explain in part the wide variability in reported sexual potency rates (9--86%) following prostate cancer surgery. Any technology capable of providing improved identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery would be of great assistance in improving sexual function after surgery, and result in direct patient benefit. Optical coherence tomography (OCT) is a noninvasive optical imaging technique capable of performing high-resolution cross-sectional in vivo and in situ imaging of microstructures in biological tissues. OCT imaging of the cavernous nerves in the rat and human prostate has recently been demonstrated. However, improvements in the OCT system and the quality of the images for identification of the cavernous nerves is necessary before clinical use. The following chapters describe complementary approaches to improving identification and imaging of the cavernous nerves during OCT of the prostate gland. After the introduction to OCT imaging of the prostate gland, the optimal wavelength for deep imaging of the prostate is studied in Chapter 2. An oblique-incidence single point measurement technique using a normal-detector scanning system was implemented to determine the absorption and reduced scattering coefficients, mua and m's , of fresh canine prostate tissue, ex vivo, from the diffuse reflectance profile of near-IR light as a function of source-detector distance. The effective attenuation coefficient, mueff, and the Optical Penetration Depth (OPD) were

  15. Ultrasound imaging accurately identifies the intercostobrachial nerve

    Directory of Open Access Journals (Sweden)

    Ahmed K. Thallaj

    2015-10-01

    Full Text Available Objectives: To test the hypothesis that identification and blockade of the intercostobrachial nerve (ICBN can be achieved under ultrasound (US guidance using a small volume of local anesthetic. Methods: Twenty-eight adult male volunteers were examined at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from November 2012 to September 2013. Intercostobrachial nerve blockade was performed using one ml of 2% lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. Results: The ICBN appears as a hyper-echoic structure. The nerve diameter was 2.3±0.28 mm, and the depth was 9±0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3±1.6 cm anteriorly; 6.2±2.9 cm posteriorly; 9.4±2.9 cm proximally; and 9.2±4.4 cm distally. Intercostobrachial nerve blockade using one ml of local anesthetic was successful in all cases. Conclusion: The present study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade.

  16. Stimulation of host bone marrow stromal cells by sympathetic nerves promotes breast cancer bone metastasis in mice.

    Directory of Open Access Journals (Sweden)

    J Preston Campbell

    2012-07-01

    Full Text Available Bone and lung metastases are responsible for the majority of deaths in patients with breast cancer. Following treatment of the primary cancer, emotional and psychosocial factors within this population precipitate time to recurrence and death, however the underlying mechanism(s remain unclear. Using a mouse model of bone metastasis, we provide experimental evidence that activation of the sympathetic nervous system, which is one of many pathophysiological consequences of severe stress and depression, promotes MDA-231 breast cancer cell colonization of bone via a neurohormonal effect on the host bone marrow stroma. We demonstrate that induction of RANKL expression in bone marrow osteoblasts, following β2AR stimulation, increases the migration of metastatic MDA-231 cells in vitro, independently of SDF1-CXCR4 signaling. We also show that the stimulatory effect of endogenous (chronic stress or pharmacologic sympathetic activation on breast cancer bone metastasis in vivo can be blocked with the β-blocker propranolol, and by knockdown of RANK expression in MDA-231 cells. These findings indicate that RANKL promotes breast cancer cell metastasis to bone via its pro-migratory effect on breast cancer cells, independently of its effect on bone turnover. The emerging clinical implication, supported by recent epidemiological studies, is that βAR-blockers and drugs interfering with RANKL signaling, such as Denosumab, could increase patient survival if used as adjuvant therapy to inhibit both the early colonization of bone by metastatic breast cancer cells and the initiation of the "vicious cycle" of bone destruction induced by these cells.

  17. Stimulation of host bone marrow stromal cells by sympathetic nerves promotes breast cancer bone metastasis in mice.

    Science.gov (United States)

    Campbell, J Preston; Karolak, Matthew R; Ma, Yun; Perrien, Daniel S; Masood-Campbell, S Kathryn; Penner, Niki L; Munoz, Steve A; Zijlstra, Andries; Yang, Xiangli; Sterling, Julie A; Elefteriou, Florent

    2012-07-01

    Bone and lung metastases are responsible for the majority of deaths in patients with breast cancer. Following treatment of the primary cancer, emotional and psychosocial factors within this population precipitate time to recurrence and death, however the underlying mechanism(s) remain unclear. Using a mouse model of bone metastasis, we provide experimental evidence that activation of the sympathetic nervous system, which is one of many pathophysiological consequences of severe stress and depression, promotes MDA-231 breast cancer cell colonization of bone via a neurohormonal effect on the host bone marrow stroma. We demonstrate that induction of RANKL expression in bone marrow osteoblasts, following β2AR stimulation, increases the migration of metastatic MDA-231 cells in vitro, independently of SDF1-CXCR4 signaling. We also show that the stimulatory effect of endogenous (chronic stress) or pharmacologic sympathetic activation on breast cancer bone metastasis in vivo can be blocked with the β-blocker propranolol, and by knockdown of RANK expression in MDA-231 cells. These findings indicate that RANKL promotes breast cancer cell metastasis to bone via its pro-migratory effect on breast cancer cells, independently of its effect on bone turnover. The emerging clinical implication, supported by recent epidemiological studies, is that βAR-blockers and drugs interfering with RANKL signaling, such as Denosumab, could increase patient survival if used as adjuvant therapy to inhibit both the early colonization of bone by metastatic breast cancer cells and the initiation of the "vicious cycle" of bone destruction induced by these cells.

  18. Magnetic resonance imaging study of lumbosacral spinal cord nerves before artificial somatic-central nervous system-autonomic reflex pathway establish ment

    International Nuclear Information System (INIS)

    Deng Xianbo; Kong Xiangquan; Feng Gansheng; Han Ping; Liu Dingxi; Ma Hui

    2005-01-01

    Objective: To investigate the value of MRI as imaging technique for lumbosacral spinal nerves before artificial somatic-central nervous system-autonomic reflex pathway establish ment. Methods: Conventional MRI and T 2 W CISS 3D were performed in 10 patients with neurogenic bladder planned for the operation of artificial somatic-central nervous system-autonomic reflex pathway. The Three-dimensional data were then constructed into composite images using a standard multiple planar reformation (MPR). Results: Five patients showed tethered spinal cord syndrome, whose spinal cord nerves were circuitous distributed and had abnormity number when penetrated the dura. Of these 5 patients, one patient was accompanied by spinal cord vas malformation. Four patients had vertebral fracture and spinal injury, and the other one patients demonstrated tumor in vertebral canal on MRI examinations. The spinal cord nerves in these 5 patients floated down river and had normal number of spinal cord nerves. Conclusion: Conventional MRI and T 2 W CISS 3D MRI were essential for the pre-operative planning of artificial somatic-central nervous system-autonomic reflex pathway, especially in patients with tethered spinal cord syndrome. Spinal cord nerves distribute and anterior and posterior roots array can be clearly showed by MPR. (authors)

  19. Polyphenols, Antioxidants and the Sympathetic Nervous System.

    Science.gov (United States)

    Bruno, Rosa Maria; Ghiadoni, Lorenzo

    2018-01-01

    A high dietary intake of polyphenols has been associated with a reduced cardiovascular mortality, due to their antioxidant properties. However, growing evidence suggests that counteracting oxidative stress in cardiovascular disease might also reduce sympathetic nervous system overactivity. This article reviews the most commonly used techniques to measure sympathetic activity in humans; the role of sympathetic activation in the pathophysiology of cardiovascular diseases; current evidence demonstrating that oxidative stress is involved in the regulation of sympathetic activity and how antioxidants and polyphenols might counteract sympathetic overactivity, particularly focusing on preliminary data from human studies. The main mechanisms by which polyphenols are cardioprotective are related to the improvement of vascular function and their anti-atherogenic effect. Furthermore, a blood pressure-lowering effect was consistently demonstrated in randomized controlled trials in humans, when the effect of flavonoid-rich foods, such as tea and chocolate, was tested. More recent studies suggest that inhibition of sympathetic overactivity might be one of the mechanisms by which these substances exert their cardioprotective effects. Indeed, an increased adrenergic traffic to the vasculature is a major mechanism of disease in a number of cardiovascular and extra-cardiac diseases, including hypertension, obesity, metabolic syndrome and heart failure. A considerable body of evidence, mostly from experimental studies, support the hypothesis that reactive oxygen species might exert sympathoexcitatory effects both at the central and at the peripheral level. Accordingly, supplementation with antioxidants might reduce adrenergic overdrive to the vasculature and blunt cardiovascular reactivity to stress. While supplementation with "classical" antioxidants such as ROS-scavengers has many limitations, increasing the intake of polyphenol-rich foods seems to be a promising novel therapeutic

  20. Sympathetic vasoconstriction takes an unexpected pannexin detour

    DEFF Research Database (Denmark)

    Schak Nielsen, Morten

    2015-01-01

    Sympathetic vasoconstriction plays an important role in the control of blood pressure and the distribution of blood flow. In this issue of Science Signaling, Billaud et al. show that sympathetic vasoconstriction occurs through a complex scheme involving the activation of large-pore pannexin 1...... channels and the subsequent release of adenosine triphosphate that promotes contraction in an autocrine and paracrine manner. This elaborate mechanism may function as a point of intercept for other signaling pathways-for example, in relation to the phenomenon "functional sympatholysis," in which exercise...... abrogates sympathetic vasoconstriction in skeletal muscle. Because pannexin 1 channels are inhibited by nitric oxide, they may function as a switch to turn off adrenergic signaling in skeletal muscle during exercise....

  1. RESTING SYMPATHETIC BAROREFLEX SENSITIVITY IN SUBJECTS WITH LOW AND HIGH TOLERANCE TO CENTRAL HYPOVOLEMIA INDUCED BY LOWER BODY NEGATIVE PRESSURE

    Directory of Open Access Journals (Sweden)

    Carmen eHinojosa-Laborde

    2014-06-01

    Full Text Available Central hypovolemia elicited by orthostasis or hemorrhage triggers sympathetically-mediated baroreflex responses to maintain organ perfusion; these reflexes are less sensitive in patients with orthostatic intolerance, and during conditions of severe blood loss, may result in cardiovascular collapse (decompensatory or circulatory shock. The ability to tolerate central hypovolemia is variable and physiological factors contributing to tolerance are emerging. We tested the hypothesis that resting muscle sympathetic nerve activity (MSNA and sympathetic baroreflex sensitivity (BRS are attenuated in male and female subjects who have low tolerance (LT to central hypovolemia induced by lower body negative pressure (LBNP. MSNA and diastolic arterial pressure (DAP were recorded in 47 human subjects who subsequently underwent LBNP to tolerance (onset of presyncopal symptoms. LT subjects experienced presyncopal symptoms prior to completing LBNP of -60 mm Hg, and subjects with high tolerance (HT experienced presyncopal symptoms after completing LBNP after -60 mmHg. Contrary to our hypothesis, resting MSNA burst incidence was not different between LT and HT subjects, and was not related to time to presyncope. BRS was assessed as the slope of the relationship between spontaneous fluctuations in DAP and MSNA during 5 min of supine rest. MSNA burst incidence/DAP correlations were greater than or equal to 0.5 in 37 subjects (LT: n= 9; HT: n=28, and BRS was not different between LT and HT (-1.8 ± 0.3 vs. -2.2 ± 0.2 bursts•(100 beats-1•mmHg-1, p=0.29. We conclude that tolerance to central hypovolemia is not related to either resting MSNA or sympathetic BRS.

  2. Is it time for cardiac innervation imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Knuuti, J. [Turku Univ., Turku (Finland) Turku PET Center; Sipola, P. [Kuopio Univ., Kuopio (Finland)

    2005-03-01

    The autonomic nervous system plays an important role in the regulation of cardiac function and the regional distribution of cardiac nerve terminals can be visualized using scintigraphic techniques. The most commonly used tracer is iodine-123-metaiodobenzylguanidine (MIBG) but C-11-hydroxyephedrine has also been used with PET. When imaging with MIBG, the ratio of heart-to-mediastinal counts is used as an index of tracer uptake, and regional distribution is also assessed from tomographic images. The rate of clearance of the tracer can also be measured and indicates the function of the adrenergic system. Innervation imaging has been applied in patients with susceptibility to arrythmias, coronary artery disease, hypertrophic and dilated cardiomyopathy and anthracycline induced cardiotoxicity. Abnormal adrenergic innervation or function appear to exist in many pathophysiological conditions indicating that sympathetic neurons are very susceptible to damage. Abnormal findings in innervation imaging also appear to have significant prognostic value especially in patients with cardiomyopathy. Recently, it has also been shown that innervation imaging can monitor drug-induced changes in cardiac adrenergic activity. Although innervation imaging holds great promise for clinical use, the method has not received wider clinical acceptance. Larger randomized studies are required to confirm the value of innervation imaging in various specific indications.

  3. Diagnostic nerve ultrasonography; Diagnostische Nervensonographie

    Energy Technology Data Exchange (ETDEWEB)

    Baeumer, T. [Universitaet zu Luebeck CBBM, Haus 66, Institut fuer Neurogenetik, Luebeck (Germany); Grimm, A. [Universitaetsklinikum Tuebingen, Klinik und Poliklinik fuer Neurologie, Tuebingen (Germany); Schelle, T. [Staedtisches Klinikum Dessau, Neurologische Klinik, Dessau (Germany)

    2017-03-15

    For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. Using ultrasonography for peripheral nerve diagnostics. With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves. (orig.) [German] Fuer die Diagnostik von Nervenlaesionen ist ein bildgebendes Verfahren zur Darstellung des peripheren Nervs und seiner ihn umgebenden Strukturen fuer eine aetiologische Einordnung erforderlich. Mit der klinisch-neurologischen Untersuchung und Elektrophysiologie ist eine funktionelle Aussage ueber die Nervenlaesion moeglich. In der Standard-MRT-Untersuchung wird der periphere Nerv nur unzureichend gut dargestellt. Die MRT-Neurographie ist ein sehr gutes, aber auch zeit- und ressourcenintensives Verfahren. Nutzung des Ultraschalls fuer die

  4. The cochlear nerve canal and internal auditory canal in children with normal cochlea but cochlear nerve deficiency

    International Nuclear Information System (INIS)

    Yan, Fei; Li, Jianhong; Xian, Junfang; Wang, Zhenchang; Mo, Lingyan

    2013-01-01

    Background: There is an increasing frequency of requests for cochlear implantation (CI) in deaf children and more detailed image information is necessary for selecting appropriate candidates. Cochlear nerve deficiency (CND) is a contraindication to CI. Magnetic resonance imaging (MRI) has been used to evaluate the integrity of the cochlear nerve. The abnormalities of the cochlear nerve canal (CNC) and internal auditory canal (IAC) have been reported to be associated with CND. Purpose: To correlate CNC manifestation, size, and IAC diameter on high-resolution CT (HRCT) with CND diagnosed by MRI in children. Material and Methods: HRCT images from 35 sensorineurally deaf children who had normal cochlea but bilateral or unilateral CND diagnosed by MRI were studied retrospectively. The CNC and IAC manifestation and size were assessed and correlated with CND. Results: CND was diagnosed by MRI in 54/70 ears (77.1%). Thirty-two ears had an absent cochlear nerve (59.3%), while 22 ears had a small cochlear nerve (40.7%). The CNC diameter was 2.0 mm in 11 ears (20.4%). The IAC diameter was 3.0 mm in 29 ears (53.7%). Conclusion: The hypoplastic CNC might be more highly indicative of CND than that of a narrow IAC

  5. Post-traumatic Unilateral Avulsion of the Abducens Nerve with Damage to Cranial Nerves VII and VIII: Case Report.

    Science.gov (United States)

    Yamasaki, Fumiyuki; Akiyama, Yuji; Tsumura, Ryu; Kolakshyapati, Manish; Adhikari, Rupendra Bahadur; Takayasu, Takeshi; Nosaka, Ryo; Kurisu, Kaoru

    2016-07-01

    Traumatic injuries of the abducens nerve as a consequence of facial and/or head trauma occur with or without associated cervical or skull base fracture. This is the first report on unilateral avulsion of the abducens nerve in a 29-year-old man with severe right facial trauma. In addition, he exhibited mild left facial palsy, and moderate left hearing disturbance. Magnetic resonance imaging (MRI) using fast imaging employing steady-state acquisition (FIESTA) revealed avulsion of left sixth cranial nerve. We recommend thin-slice MR examination in patients with abducens palsy after severe facial and/or head trauma.

  6. Compressive neuropathy of the first branch of the lateral plantar nerve: a study by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Rogéria Nobre Rodrigues

    2015-12-01

    Full Text Available Abstract Objective: To assess the prevalence of isolated findings of abnormalities leading to entrapment of the lateral plantar nerve and respective branches in patients complaining of chronic heel pain, whose magnetic resonance imaging exams have showed complete selective fatty atrophy of the abductor digiti quinti muscle. Materials and Methods: Retrospective, analytical, and cross-sectional study. The authors selected magnetic resonance imaging of hindfoot of 90 patients with grade IV abductor digiti quinti muscle atrophy according to Goutallier and Bernageau classification. Patients presenting with minor degrees of fatty muscle degeneration (below grade IV and those who had been operated on for nerve decompression were excluded. Results: A female prevalence (78.8% was observed, and a strong correlation was found between fatty muscle atrophy and plantar fasciitis in 21.2%, and ankle varices, in 16.8% of the patients. Conclusion: Fatty atrophy of the abductor digiti quinti muscle is strongly associated with neuropathic alterations of the first branch of the lateral plantar nerve. The present study showed a significant association between plantar fasciitis and ankle varices with grade IV atrophy of the abductor digiti quinti muscle.

  7. CASE SERIES: Malignant Peripheral Nerve Sheath Tumor in the Course of the Mandibular Nerve.

    Science.gov (United States)

    Monika, Probst; Steffen, Koerdt; Maximilian, Ritschl Lucas; Oliver, Bissinger; Friederike, Liesche; Jens, Gempt; Bernhard, Meyer; Egon, Burian; Nina, Lummel; Andreas, Kolk

    2018-06-05

    Malignant peripheral nerve sheath tumors (MPNST) are infiltrating, aggressive tumors belonging to the group of soft tissue sarcomas. This report refers to three patients with a tumorous swelling in the entire inferior alveolar nerve (IAN) with similar disease courses suspect for a MPNST, which is particularly rare in the trigeminal nerve. Diagnostic tools, surgical proceedings and reconstructive procedures were highlighted. Three male patients (58-68 years), who suffered from numbness, pain and mild swelling in the sensation area served by the mental nerve presented at the department of oral and maxillofacial surgery and underwent diagnostic workup including CT, MRI, F18-PET-CT, as well as a biopsy of the clinical visible tumor mass with histopathological and molecular pathological analysis. MR imaging revealed the full extent of the tumor comprising the course of the entire mandibular nerve (one case bilateral) starting in the trigeminal ganglion through the IAN and ending in the mental foramen. Hence, both a neurosurgical and maxillofacial intervention with jaw replacement were necessary. Adjuvant radiation of the intracranial closed resection margins, and in one case of parts of the mandible was required. In order to reveal the full extent of tumor spread of MPNSTs sufficient preoperative imaging is crucial as it is an important step in therapy planning. MRI and PET-CT are the imaging modalities with the best prospect of success in depicting the whole extent of the disease. Radical surgical management is the treatment of choice whereas radiochemotherapy shows an ancillary part. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Rapid, automated mosaicking of the human corneal subbasal nerve plexus.

    Science.gov (United States)

    Vaishnav, Yash J; Rucker, Stuart A; Saharia, Keshav; McNamara, Nancy A

    2017-11-27

    Corneal confocal microscopy (CCM) is an in vivo technique used to study corneal nerve morphology. The largest proportion of nerves innervating the cornea lie within the subbasal nerve plexus, where their morphology is altered by refractive surgery, diabetes and dry eye. The main limitations to clinical use of CCM as a diagnostic tool are the small field of view of CCM images and the lengthy time needed to quantify nerves in collected images. Here, we present a novel, rapid, fully automated technique to mosaic individual CCM images into wide-field maps of corneal nerves. We implemented an OpenCV image stitcher that accounts for corneal deformation and uses feature detection to stitch CCM images into a montage. The method takes 3-5 min to process and stitch 40-100 frames on an Amazon EC2 Micro instance. The speed, automation and ease of use conferred by this technique is the first step toward point of care evaluation of wide-field subbasal plexus (SBP) maps in a clinical setting.

  9. A Deep Learning Approach to Digitally Stain Optical Coherence Tomography Images of the Optic Nerve Head.

    Science.gov (United States)

    Devalla, Sripad Krishna; Chin, Khai Sing; Mari, Jean-Martial; Tun, Tin A; Strouthidis, Nicholas G; Aung, Tin; Thiéry, Alexandre H; Girard, Michaël J A

    2018-01-01

    To develop a deep learning approach to digitally stain optical coherence tomography (OCT) images of the optic nerve head (ONH). A horizontal B-scan was acquired through the center of the ONH using OCT (Spectralis) for one eye of each of 100 subjects (40 healthy and 60 glaucoma). All images were enhanced using adaptive compensation. A custom deep learning network was then designed and trained with the compensated images to digitally stain (i.e., highlight) six tissue layers of the ONH. The accuracy of our algorithm was assessed (against manual segmentations) using the dice coefficient, sensitivity, specificity, intersection over union (IU), and accuracy. We studied the effect of compensation, number of training images, and performance comparison between glaucoma and healthy subjects. For images it had not yet assessed, our algorithm was able to digitally stain the retinal nerve fiber layer + prelamina, the RPE, all other retinal layers, the choroid, and the peripapillary sclera and lamina cribrosa. For all tissues, the dice coefficient, sensitivity, specificity, IU, and accuracy (mean) were 0.84 ± 0.03, 0.92 ± 0.03, 0.99 ± 0.00, 0.89 ± 0.03, and 0.94 ± 0.02, respectively. Our algorithm performed significantly better when compensated images were used for training (P deep learning algorithm can simultaneously stain the neural and connective tissues of the ONH, offering a framework to automatically measure multiple key structural parameters of the ONH that may be critical to improve glaucoma management.

  10. Neuronal uptake and metabolism of 2- and 6-fluorodopamine: false neurotransmitters for positron emission tomographic imaging of sympathetically innervated tissues

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhofer, G.; Hovevey-Sion, D.; Kopin, I.J.; Miletich, R.; Kirk, K.L.; Finn, R.; Goldstein, D.S.

    1989-01-01

    The neuronal uptake and metabolism of 2-fluorodopamine (2F-dopamine), 6-fluorodopamine (6F-dopamine) and tritium-labeled dopamine were compared in heart, submaxillary gland and spleen of rats to assess the utility of 18F-labeled 2F- or 6F-dopamine for positron emission tomographic imaging of sympathetically innervated tissues. Tritiated dopamine with and without 2F- or 6F-dopamine, or tritiated 2F-dopamine alone, were injected i.v. into rats that were or were not pretreated with desipramine to block catecholamine neuronal uptake or with reserpine to block vesicular translocation of catecholamines. Tissue and plasma samples were obtained at intervals up to 1 hr after injections. At 1 hr after injection of tritiated dopamine, tritium-labeled norepinephrine, dopamine, dihydroxyphenylacetic acid and dihydroxyphenylglucol accounted for less than 2% of the tritium in plasma but up to 92% of that in tissues; tritiated norepinephrine accounted for 70% or more of the tritium in tissues. In contrast, at 1 hr after injection of tritiated 2F-dopamine, tritiated 2F-norepinephrine accounted for 30 to 46% of the tritium in tissues. Desipramine and reserpine pretreatment blocked the tissue accumulation of tritiated and fluorinated dopamine as well as their dihydroxy-metabolites, indicating that accumulation of exogenous norepinephrine and dopamine analogs was within sympathetic storage vesicles. Relative to the doses of dopamine precursors, less 2F- and 6F-norepinephrine accumulated in tissues than tritiated norepinephrine, due largely to inefficient beta-hydroxylation of fluorinated dopamine.

  11. Neuronal uptake and metabolism of 2- and 6-fluorodopamine: false neurotransmitters for positron emission tomographic imaging of sympathetically innervated tissues

    International Nuclear Information System (INIS)

    Eisenhofer, G.; Hovevey-Sion, D.; Kopin, I.J.; Miletich, R.; Kirk, K.L.; Finn, R.; Goldstein, D.S.

    1989-01-01

    The neuronal uptake and metabolism of 2-fluorodopamine (2F-dopamine), 6-fluorodopamine (6F-dopamine) and tritium-labeled dopamine were compared in heart, submaxillary gland and spleen of rats to assess the utility of 18F-labeled 2F- or 6F-dopamine for positron emission tomographic imaging of sympathetically innervated tissues. Tritiated dopamine with and without 2F- or 6F-dopamine, or tritiated 2F-dopamine alone, were injected i.v. into rats that were or were not pretreated with desipramine to block catecholamine neuronal uptake or with reserpine to block vesicular translocation of catecholamines. Tissue and plasma samples were obtained at intervals up to 1 hr after injections. At 1 hr after injection of tritiated dopamine, tritium-labeled norepinephrine, dopamine, dihydroxyphenylacetic acid and dihydroxyphenylglucol accounted for less than 2% of the tritium in plasma but up to 92% of that in tissues; tritiated norepinephrine accounted for 70% or more of the tritium in tissues. In contrast, at 1 hr after injection of tritiated 2F-dopamine, tritiated 2F-norepinephrine accounted for 30 to 46% of the tritium in tissues. Desipramine and reserpine pretreatment blocked the tissue accumulation of tritiated and fluorinated dopamine as well as their dihydroxy-metabolites, indicating that accumulation of exogenous norepinephrine and dopamine analogs was within sympathetic storage vesicles. Relative to the doses of dopamine precursors, less 2F- and 6F-norepinephrine accumulated in tissues than tritiated norepinephrine, due largely to inefficient beta-hydroxylation of fluorinated dopamine

  12. Fibre optic confocal imaging (FOCI) of keratinocytes, blood vessels and nerves in hairless mouse skin in vivo

    Science.gov (United States)

    BUSSAU, L. J.; VO, L. T.; DELANEY, P. M.; PAPWORTH, G. D.; BARKLA, D. H.; KING, R. G.

    1998-01-01

    Fibre optic confocal imaging (FOCI) enabled subsurface fluorescence microscopy of the skin of hairless mice in vivo. Application of acridine orange enabled imaging of the layers of the epidermis. The corneocytes of the stratum corneum, the keratinocytes in the basal layers and redundant hair follicles were visualised at depths greater than 100 μm. Cellular and nuclear membranes of keratinocytes of the skin were visualised by the use of acridine orange and DIOC5(3). Imaging of the skin after injection of FITC-dextran revealed an extensive network of blood vessels with a size range up to 20 μm. Blood cells could be seen moving through dermal vessels and the blood circulation through the dermal vascular bed was video-taped. The fluorescent dye 4-di-2-ASP showed the presence of nerves fibres around the hair follicles and subsurface blood vessels. Comparison was made between images obtained in vivo using FOCI and in vitro scanning electron microscopy and conventional histology. FOCI offers the potential to study dynamic events in vivo, such as blood flow, skin growth, nerve regeneration and many pathological processes, in ways which have not previously been possible. PMID:9643419

  13. Enhanced sympathetic arousal in response to FMRI scanning correlates with task induced activations and deactivations.

    Directory of Open Access Journals (Sweden)

    Markus Muehlhan

    Full Text Available It has been repeatedly shown that functional magnetic resonance imaging (fMRI triggers distress and neuroendocrine response systems. Prior studies have revealed that sympathetic arousal increases, particularly at the beginning of the examination. Against this background it appears likely that those stress reactions during the scanning procedure may influence task performance and neural correlates. However, the question how sympathetic arousal elicited by the scanning procedure itself may act as a potential confounder of fMRI data remains unresolved today. Thirty-seven scanner naive healthy subjects performed a simple cued target detection task. Levels of salivary alpha amylase (sAA, as a biomarker for sympathetic activity, were assessed in samples obtained at several time points during the lab visit. SAA increased two times, immediately prior to scanning and at the end of the scanning procedure. Neural activation related to motor preparation and timing as well as task performance was positively correlated with the first increase. Furthermore, the first sAA increase was associated with task induced deactivation (TID in frontal and parietal regions. However, these effects were restricted to the first part of the experiment. Consequently, this bias of scanner related sympathetic activation should be considered in future fMRI investigations. It is of particular importance for pharmacological investigations studying adrenergic agents and the comparison of groups with different stress vulnerabilities like patients and controls or adolescents and adults.

  14. Evaluation of cardiac sympathetic nerve activity and aldosterone suppression in patients with acute decompensated heart failure on treatment containing intravenous atrial natriuretic peptide

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Toyama, Takuji; Kurabayashi, Masahiko [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Iwasaki, Toshiya; Sumino, Hiroyuki; Kumakura, Hisao; Minami, Kazutomo; Ichikawa, Shuichi [Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Matsumoto, Naoya [Nihon University School of Medicine, Department of Cardiology, Tokyo (Japan); Nakata, Tomoaki [Sapporo Medical University School of Medicine, Second (Cardiology) Department of Internal Medicine, Sapporo, Hokkaido (Japan)

    2014-09-15

    Aldosterone prevents the uptake of norepinephrine in the myocardium. Atrial natriuretic peptide (ANP), a circulating hormone of cardiac origin, inhibits aldosterone synthase gene expression in cultured cardiocytes. We evaluated the effects of intravenous ANP on cardiac sympathetic nerve activity (CSNA) and aldosterone suppression in patients with acute decompensated heart failure (ADHF). We studied 182 patients with moderate nonischemic ADHF requiring hospitalization and treated with standard therapy containing intravenous ANP and 10 age-matched normal control subjects. ANP was continuously infused for >96 h. In all subjects, delayed total defect score (TDS), heart to mediastinum ratio, and washout rate were determined by {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy. Left ventricular (LV) end-diastolic volume, end-systolic volume, and ejection fraction were determined by echocardiography. All patients with acute heart failure (AHF) were examined once within 3 days and then 4 weeks after admission, while the control subjects were examined only once (when their hemodynamics were normal). Moreover, for 62 AHF patients, plasma aldosterone concentrations were measured at admission and 1 h before stopping ANP infusion. {sup 123}I-MIBG scintigraphic and echocardiographic parameters in normal subjects were more favorable than those in patients with AHF (all p < 0.001). After treatment, all these parameters improved significantly in AHF patients (all p < 0.001). We also found significant correlation between percent changes of TDS and aldosterone concentrations (r = 0.539, p < 0.001) in 62 AHF patients. The CSNA and LV performance were all improved in AHF patients. Furthermore, norepinephrine uptake of myocardium may be ameliorated by suppressing aldosterone production after standard treatment containing intravenous ANP. (orig.)

  15. Diffusion tensor imaging can be used to detect lesions in peripheral nerves in patients with chronic inflammatory demyelinating polyneuropathy treated with subcutaneous immunoglobulin

    Energy Technology Data Exchange (ETDEWEB)

    Markvardsen, Lars H.; Andersen, Henning [Aarhus University Hospital, Department of Neurology, Aarhus C (Denmark); Vaeggemose, Michael [Aarhus University Hospital, Department of Neurology, Aarhus C (Denmark); Aarhus University Hospital, Department of Diagnostic Imaging: MR Research Centre, Aarhus (Denmark); Ringgaard, Steffen [Aarhus University Hospital, Department of Diagnostic Imaging: MR Research Centre, Aarhus (Denmark)

    2016-08-15

    Magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI) has shown that fractional anisotropy (FA) is lower in peripheral nerves in chronic inflammatory demyelinating polyneuropathy (CIDP). We examined whether DTI correlates to muscle strength or impairment. MRI of sciatic and tibial nerves was performed on 3-T MR scanner by obtaining T2- and DTI-weighted sequences with fat saturation. On each slice of T2-weighted (T2w) and DTI, the tibial and sciatic nerves were segmented and served for calculation of signal intensity. On DTI images, pixel-by-pixel calculation of FA and apparent diffusion coefficient (ADC) was done. Muscle strength at knee and ankle was determined by isokinetic dynamometry and severity of CIDP by neuropathy impairment score (NIS). Fourteen CIDP patients treated with subcutaneous immunoglobulin were compared to gender- and age-matched controls. T2w values expressed as a nerve/muscle ratio (nT2w) were unchanged in CIDP versus controls 0.93 ± 0.21 versus 1.02 ± 0.21 (P = 0.10). FA values were lower in CIDP compared to controls 0.38 ± 0.07 versus 0.45 ± 0.05 (P < 0.0001), and ADC values were higher in CIDP versus controls 1735 ± 232 versus 1593 ± 116 x 10{sup -6} mm{sup 2}/s (P = 0.005). In CIDP, FA values correlated to clinical impairment (NIS) (r = -0.57, P = 0.03), but not to muscle strength. FA value in the sciatic nerve distinguishes CIDP from controls with a sensitivity and a specificity of 92.9 %. CIDP patients have unchanged nT2w values, lower FA values, and higher ADC values of sciatic and tibial nerves compared to controls. FA values correlated to NIS but were unrelated to muscle strength. DTI of sciatic nerves seems promising to differentiate CIDP from controls. (orig.)

  16. Inflammation in CRPS: role of the sympathetic supply.

    Science.gov (United States)

    Schlereth, Tanja; Drummond, Peter D; Birklein, Frank

    2014-05-01

    Acute Complex Regional Pain Syndrome (CRPS) is associated with signs of inflammation such as increased skin temperature, oedema, skin colour changes and pain. Pro-inflammatory cytokines (tumour necrosis factor-α (TNF-α), interleukin-2 (IL-2), IL-1beta, IL-6) are up-regulated, whereas anti-inflammatory cytokines (IL-4, IL-10) are diminished. Adaptive immunity seems to be involved in CRPS pathophysiology as many patients have autoantibodies directed against β2 adrenergic and muscarinic-2 receptors. In an animal tibial fracture model changes in the innate immune response such as up-regulation of keratinocytes are also found. Additionally, CRPS is accompanied by increased neurogenic inflammation which depends mainly on neuropeptides such as CGRP and Substance P. Besides inflammatory signs, sympathetic nervous system involvement in CRPS results in cool skin, increased sweating and sympathetically-maintained pain. The norepinephrine level is lower in the CRPS-affected than contralateral limb, but sympathetic sprouting and up-regulation of alpha-adrenoceptors may result in an adrenergic supersensitivity. The sympathetic nervous system and inflammation interact: norepinephrine influences the immune system and the production of cytokines. There is substantial evidence that this interaction contributes to the pathophysiology and clinical presentation of CRPS, but this interaction is not straightforward. How inflammation in CRPS might be exaggerated by sympathetic transmitters requires further elucidation. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Normal and sonographic anatomy of selected peripheral nerves. Part I: Sonohistology and general principles of examination, following the example of the median nerve

    Directory of Open Access Journals (Sweden)

    Berta Kowalska

    2012-06-01

    Full Text Available Ultrasonography is an established method for imaging peripheral nerves. It serves to supplement the physical examination, electromyography, and magnetic resonance imaging. It enables the identification of post-traumatic changes of nerves, neuropathies secondary to compression syndromes, inflammatory or neoplastic nerve lesions as well as the evaluation of postoperative complications. In certain situations, this technique is the imaging method of choice. It is increasingly used in anesthesiology for regional anesthesia. As in the case of other ultrasound imaging studies, the examination of peripheral nerves is non-invasive, well-tolerated by patients, and relatively inexpensive. This article presents the histological structure of peripheral nerves and their appearance in ultrasonography. It also presents the examination technique, following the example of the median nerve, and includes a series of diagrams and ultrasound images. The interpretation of the shape, echogenicity, thickness and vascularity of nerves is described, as well as their relation to the surrounding tissues. The “elevator technique”, which consists of locating a set nerve at a characteristic anatomic point, and following it proximally or distally, has been explained. The undisputed benefits of the ultrasound examination have been presented, including its advantages over other diagnostic methods. These advantages include the dynamic component of the ultrasound examination and the possibility of correlating the patient’s symptoms with the ultrasound images. As an example, the proper anatomy and the ultrasonographic appearance of the median nerve were described. This nerve’s course is presented, its divisions, and characteristic reference points, so as to facilitate its location and identification, and enable subsequent use of the aforementioned “elevator technique”. This article opens a series of publications concerning anatomy, technique of examination and

  18. External auditory canal cholesteatoma and keratosis obturans: the role of imaging in preventing facial nerve injury.

    Science.gov (United States)

    McCoul, Edward D; Hanson, Matthew B

    2011-12-01

    We conducted a retrospective study to compare the clinical characteristics of external auditory canal cholesteatoma (EACC) with those of a similar entity, keratosis obturans (KO). We also sought to identify those aspects of each disease that may lead to complications. We identified 6 patients in each group. Imaging studies were reviewed for evidence of bony erosion and the proximity of disease to vital structures. All 6 patients in the EACC group had their diagnosis confirmed by computed tomography (CT), which demonstrated widening of the bony external auditory canal; 4 of these patients had critical erosion of bone adjacent to the facial nerve. Of the 6 patients with KO, only 2 had undergone CT, and neither exhibited any significant bony erosion or expansion; 1 of them developed osteomyelitis of the temporal bone and adjacent temporomandibular joint. Another patient manifested KO as part of a dermatophytid reaction. The essential component of treatment in all cases of EACC was microscopic debridement of the ear canal. We conclude that EACC may produce significant erosion of bone with exposure of vital structures, including the facial nerve. Because of the clinical similarity of EACC to KO, misdiagnosis is possible. Temporal bone imaging should be obtained prior to attempts at debridement of suspected EACC. Increased awareness of these uncommon conditions is warranted to prompt appropriate investigation and prevent iatrogenic complications such as facial nerve injury.

  19. Functionality of the baroreceptor nerves in heart rate regulation

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, Mette

    2011-01-01

    are a consequence of the memory encapsulated by the models, and the nonlinearity gives rise to sigmoidal response curves. The nonlinear afferent baroreceptor models are coupled with an effector model, and the coupled model has been used to predict baroreceptor feedback regulation of heart rate during postural...... change from sitting to standing and during head-up tilt. The efferent model couples the afferent nerve paths to the sympathetic and parasympathetic outflow, and subsequently predicts the build up of an action potential at the sinus knot of the heart. In this paper, we analyze the nonlinear afferent model...... and show that the coupled model is able to predict heart rate regulation using blood pressure data as an input...

  20. Deleterious effect of salusin-β in paraventricular nucleus on sympathetic activity and blood pressure via NF-κB signaling in a rat model of obesity hypertension.

    Science.gov (United States)

    Huang, Xiaodong; Wang, Yanchun; Ren, Kuang

    2015-08-01

    The paraventricular nucleus (PVN) has been shown to play a critical role in regulating blood pressure and sympathetic activity in obesity hypertension (OH). Salusin-β is a bioactive peptide with potential roles in mediating cardiovascular activity. The study was designed to test the hypothesis that salusin-β in the PVN can modulate sympathetic activity and blood pressure in OH. Male Sprague-Dawley rats were used to induce OH by a 12-week feeding of a high-fat diet (42% kcal as fat). Microinjection of salusin-β into the PVN increased the renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) in a dose-dependent manner, whereas salusin-β antibody elicited significant decreases in RSNA, MAP and HR, and abolished the effects of salusin-β only in the OH rats. As expected, the OH rats had a higher norepinephrine level, which was further increased by salusin-β. Furthermore, salusin-β in the PVN accelerated the nuclear translocation of the p65 subunit of nuclear factor kappa B (NF-KB) and the degradation of IKB-α (an endogenous inhibitor of NF-KB). Pretreatment with pyrrolidine dithiocarbamate (an exogenous inhibitor of NF-KB) decreased RSNA, MAP and HR, and abolished the effects of salusin-β in the PVN in the OH rats. We concluded that salusin-β in the PVN markedly increased sympathetic outflow and blood pressure in diet-induced OH rats via NF-κB signaling.