The bulbospinal network controlling the phrenic motor system: Laterality and course of descending projections.

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Ghali, Michael George Zaki

2017-08-01

The respiratory rhythm is generated by the parafacial respiratory group, Bötzinger complex, and pre-Bötzinger complex and relayed to pre-motor neurons, which in turn project to and control respiratory motor outputs in the brainstem and spinal cord. The phrenic nucleus is one such target, containing phrenic motoneurons (PhMNs), which supply the diaphragm, the primary inspiratory muscle in mammals. While some investigators have demonstrated both ipsi- and contralateral bulbophrenic projections, there exists controversy regarding the relative physiological contribution of each to phasic and tonic drive to PhMNs and at which levels decussations occur. Following C1- or C2 spinal cord hemisection-induced silencing of the ipsilateral phrenic/diaphragm activity, respiratory stressor-induced, as well as spontaneous, recovery of crossed phrenic activity is observed, suggesting an important contribution of pathways crossing below the level of injury in driving phrenic motor output. The precise mechanisms underlying this recovery are debated. In this review, we seek to present a comprehensive discussion of the organization of the bulbospinal network controlling PhMNs, a thorough appreciation of which is necessary for understanding neural respiratory control, accurate interpretation of studies investigating respiratory recovery following spinal cord injury, and targeted development of therapies for respiratory neurorehabilitation in patients sustaining high cervical cord injury. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

WGA-Alexa transsynaptic labeling in the phrenic motor system of adult rats: Intrapleural injection versus intradiaphragmatic injection.

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Buttry, Janelle L; Goshgarian, Harry G

2015-02-15

Intrapleural injection of CTB-Alexa 488, a retrograde tracer, provides an alternative labeling technique to the surgically invasive laparotomy required for intradiaphragmatic injection. However, CTB-Alexa 488 is incapable of crossing synapses restricting the tracer to the phrenic nuclei and the intercostal motor nuclei in the spinal cord. Intrapleural injection of WGA-Alexa 488, a transsynaptic tracer, provides a method to label the respiratory motor pathway in both the spinal cord and medulla. Intradiaphragmatic injection of WGA-Alexa 594 and vagal nerve injections of True blue were used to confirm the phrenic nuclei and to differentiate between the rVRG and the NA in the medulla. Following intrapleural injection, WGA-Alexa 488 was retrogradely transported to the phrenic nuclei and to the intercostal motor nuclei. Subsequently WGA-Alexa 488 was transsynaptically transported from the phrenic motoneurons to the pre-motor neurons in the rVRG that provide the descending drive to the phrenic neurons during inspiration. In addition WGA-Alexa 488 was identified in select cells of the NA confirmed by a dual label of both WGA-Alexa 488 and True blue. WGA-Alexa 488 demonstrates retrograde transsynaptic labeling following intrapleural injection whereas the previous method of injecting CTB-Alexa 488 only demonstrates retrograde labeling. Intrapleural injection of WGA-Alexa fluor conjugates is an effective method to transsynaptically label the phrenic motor system providing an alternative for the invasive laparotomy required for intradiaphragmatic injections. Furthermore, the study provides the first anatomical evidence of a direct synaptic relationship between rVRG and select NA cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Spinal 5-HT7 Receptors and Protein Kinase A Constrain Intermittent Hypoxia-Induced Phrenic Long-term Facilitation

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Hoffman, M.S.; Mitchell, G.S.

2013-01-01

Phrenic long-term facilitation (pLTF) is a form of serotonin-dependent respiratory plasticity induced by acute intermittent hypoxia (AIH). pLTF requires spinal Gq protein-coupled serotonin-2 receptor (5-HT2) activation, new synthesis of brain-derived neurotrophic factor (BDNF) and activation of its high-affinity receptor, TrkB. Intrathecal injections of selective agonists for Gs protein-coupled receptors (adenosine 2A and serotonin-7; 5-HT7) also induce long-lasting phrenic motor facilitation via TrkB “trans-activation.” Since serotonin release near phrenic motor neurons may activate multiple serotonin receptor subtypes, we tested the hypothesis that 5-HT7 receptor activation contributes to AIH-induced pLTF. A selective 5-HT7 receptor antagonist (SB-269970, 5mM, 12μl) was administered intrathecally at C4 to anesthetized, vagotomized and ventilated rats prior to AIH (3, 5-min episodes, 11% O2). Contrary to predictions, pLTF was greater in SB-269970 treated versus control rats (80±11% vs 45±6% 60 min post-AIH; p<0.05). Hypoglossal LTF was unaffected by spinal 5-HT7 receptor inhibition, suggesting that drug effects were localized to the spinal cord. Since 5-HT7 receptors are coupled to protein kinase A (PKA), we tested the hypothesis that PKA inhibits AIH-induced pLTF. Similar to 5-HT7 receptor inhibition, spinal PKA inhibition (KT-5720, 100μM, 15μl) enhanced pLTF (99±15% 60 min post-AIH; p<0.05). Conversely, PKA activation (8-br-cAMP, 100μM, 15μl) blunted pLTF versus control rats (16±5% vs 45±6% 60 min post-AIH; p<0.05). These findings suggest a novel mechanism whereby spinal Gs protein-coupled 5-HT7 receptors constrain AIH-induced pLTF via PKA activity. PMID:23850591

Transmitter-controlled properties of α-motoneurones causing long-lasting motor discharge to brief excitatory inputs

DEFF Research Database (Denmark)

Hounsgaard, J.; Hultborn, H.; Kiehn, O.

1986-01-01

Brief sensory inputs to intact conscious subjects commonly trigger complex long-lasting motor responses, in which higher cerebral mechanisms, or even voluntary action, may be integrative parts. However, long-lasting motor discharge following brief afferent stimulation is also observed in reduced ...... flipflops, which are set at one of two levels by short excitatory or inhibitory inputs. However, when the whole motoneuronal pool is considered, many different levels can be maintained by recruitment of new units.......Brief sensory inputs to intact conscious subjects commonly trigger complex long-lasting motor responses, in which higher cerebral mechanisms, or even voluntary action, may be integrative parts. However, long-lasting motor discharge following brief afferent stimulation is also observed in reduced...

Long pacing pulses reduce phrenic nerve stimulation in left ventricular pacing.

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Hjortshøj, Søren; Heath, Finn; Haugland, Morten; Eschen, Ole; Thøgersen, Anna Margrethe; Riahi, Sam; Toft, Egon; Struijk, Johannes Jan

2014-05-01

Phrenic nerve stimulation is a major obstacle in cardiac resynchronization therapy (CRT). Activation characteristics of the heart and phrenic nerve are different with higher chronaxie for the heart. Therefore, longer pulse durations could be beneficial in preventing phrenic nerve stimulation during CRT due to a decreased threshold for the heart compared with the phrenic nerve. We investigated if long pulse durations decreased left ventricular (LV) thresholds relatively to phrenic nerve thresholds in humans. Eleven patients, with indication for CRT and phrenic nerve stimulation at the intended pacing site, underwent determination of thresholds for the heart and phrenic nerve at different pulse durations (0.3-2.9 milliseconds). The resulting strength duration curves were analyzed by determining chronaxie and rheobase. Comparisons for those parameters were made between the heart and phrenic nerve, and between the models of Weiss and Lapicque as well. In 9 of 11 cases, the thresholds decreased faster for the LV than for the phrenic nerve with increasing pulse duration. In 3 cases, the thresholds changed from unfavorable for LV stimulation to more than a factor 2 in favor of the LV. The greatest change occurred for pulse durations up to 1.5 milliseconds. The chronaxie of the heart was significantly higher than the chronaxie of the phrenic nerve (0.47 milliseconds vs. 0.22 milliseconds [P = 0.029, Lapicque] and 0.79 milliseconds vs. 0.27 milliseconds [P = 0.033, Weiss]). Long pulse durations lead to a decreased threshold of the heart relatively to the phrenic nerve and may prevent stimulation of the phrenic nerve in a clinical setting. © 2013 Wiley Periodicals, Inc.

Anatomy and physiology of phrenic afferent neurons.

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Nair, Jayakrishnan; Streeter, Kristi A; Turner, Sara M F; Sunshine, Michael D; Bolser, Donald C; Fox, Emily J; Davenport, Paul W; Fuller, David D

2017-12-01

Large-diameter myelinated phrenic afferents discharge in phase with diaphragm contraction, and smaller diameter fibers discharge across the respiratory cycle. In this article, we review the phrenic afferent literature and highlight areas in need of further study. We conclude that 1 ) activation of both myelinated and nonmyelinated phrenic sensory afferents can influence respiratory motor output on a breath-by-breath basis; 2 ) the relative impact of phrenic afferents substantially increases with diaphragm work and fatigue; 3 ) activation of phrenic afferents has a powerful impact on sympathetic motor outflow, and 4 ) phrenic afferents contribute to diaphragm somatosensation and the conscious perception of breathing. Much remains to be learned regarding the spinal and supraspinal distribution and synaptic contacts of myelinated and nonmyelinated phrenic afferents. Similarly, very little is known regarding the potential role of phrenic afferent neurons in triggering or modulating expression of respiratory neuroplasticity. Copyright © 2017 the American Physiological Society.

Phrenicotomy alters phrenic long-term facilitation following intermittent hypoxia in anesthetized rats

OpenAIRE

Sandhu, M. S.; Lee, K. Z.; Fregosi, R. F.; Fuller, D. D.

2010-01-01

Intermittent hypoxia (IH) can induce a persistent increase in neural drive to the respiratory muscles known as long-term facilitation (LTF). LTF of phrenic inspiratory activity is often studied in anesthetized animals after phrenicotomy (PhrX), with subsequent recordings being made from the proximal stump of the phrenic nerve. However, severing afferent and efferent axons in the phrenic nerve has the potential to alter the excitability of phrenic motoneurons, which has been hypothesized to be...

The role of spinal GABAergic circuits in the control of phrenic nerve motor output.

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Marchenko, Vitaliy; Ghali, Michael G Z; Rogers, Robert F

2015-06-01

While supraspinal mechanisms underlying respiratory pattern formation are well characterized, the contribution of spinal circuitry to the same remains poorly understood. In this study, we tested the hypothesis that intraspinal GABAergic circuits are involved in shaping phrenic motor output. To this end, we performed bilateral phrenic nerve recordings in anesthetized adult rats and observed neurogram changes in response to knocking down expression of both isoforms (65 and 67 kDa) of glutamate decarboxylase (GAD65/67) using microinjections of anti-GAD65/67 short-interference RNA (siRNA) in the phrenic nucleus. The number of GAD65/67-positive cells was drastically reduced on the side of siRNA microinjections, especially in the lateral aspects of Rexed's laminae VII and IX in the ventral horn of cervical segment C4, but not contralateral to microinjections. We hypothesize that intraspinal GABAergic control of phrenic output is primarily phasic, but also plays an important role in tonic regulation of phrenic discharge. Also, we identified respiration-modulated GABAergic interneurons (both inspiratory and expiratory) located slightly dorsal to the phrenic nucleus. Our data provide the first direct evidence for the existence of intraspinal GABAergic circuits contributing to the formation of phrenic output. The physiological role of local intraspinal inhibition, independent of descending direct bulbospinal control, is discussed. Copyright © 2015 the American Physiological Society.

Acute intermittent hypoxia induced phrenic long-term facilitation despite increased SOD1 expression in a rat model of ALS.

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Nichols, Nicole L; Satriotomo, Irawan; Harrigan, Daniel J; Mitchell, Gordon S

2015-11-01

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease characterized by motor neuron death. Since most ALS patients succumb to ventilatory failure from loss of respiratory motor neurons, any effective ALS treatment must preserve and/or restore breathing capacity. In rats over-expressing mutated super-oxide dismutase-1 (SOD1(G93A)), the capacity to increase phrenic motor output is decreased at disease end-stage, suggesting imminent ventilatory failure. Acute intermittent hypoxia (AIH) induces phrenic long-term facilitation (pLTF), a form of spinal respiratory motor plasticity with potential to restore phrenic motor output in clinical disorders that compromise breathing. Since pLTF requires NADPH oxidase activity and reactive oxygen species (ROS) formation, it is blocked by NADPH oxidase inhibition and SOD mimetics in normal rats. Thus, we hypothesized that SOD1(G93A) (mutant; MT) rats do not express AIH-induced pLTF due to over-expression of active mutant superoxide dismutase-1. AIH-induced pLTF and hypoglossal (XII) LTF were assessed in young, pre-symptomatic and end-stage anesthetized MT rats and age-matched wild-type littermates. Contrary to predictions, pLTF and XII LTF were observed in MT rats at all ages; at end-stage, pLTF was actually enhanced. SOD1 levels were elevated in young and pre-symptomatic MT rats, yet superoxide accumulation in putative phrenic motor neurons (assessed with dihydroethidium) was unchanged; however, superoxide accumulation significantly decreased at end-stage. Thus, compensatory mechanisms appear to maintain ROS homoeostasis until late in disease progression, preserving AIH-induced respiratory plasticity. Following intrathecal injections of an NADPH oxidase inhibitor (apocynin; 600 μM; 12 μL), pLTF was abolished in pre-symptomatic, but not end-stage MT rats, demonstrating that pLTF is NADPH oxidase dependent in pre-symptomatic, but NADPH oxidase independent in end-stage MT rats. Mechanisms

Phrenic motor outputs in response to bronchopulmonary C‐fibre activation following chronic cervical spinal cord injury

Science.gov (United States)

2016-01-01

Key points Activation of bronchopulmonary C‐fibres, the main chemosensitive afferents in the lung, can induce pulmonary chemoreflexes to modulate respiratory activity.Following chronic cervical spinal cord injury, bronchopulmonary C‐fibre activation‐induced inhibition of phrenic activity was exaggerated.Supersensitivity of phrenic motor outputs to the inhibitory effect of bronchopulmonary C‐fibre activation is due to a shift of phrenic motoneuron types and slow recovery of phrenic motoneuron discharge in cervical spinal cord‐injured animals.These data suggest that activation of bronchopulmonary C‐fibres may retard phrenic output recovery following cervical spinal cord injury.The alteration of phenotype and discharge pattern of phrenic motoneuron enables us to understand the impact of spinal cord injury on spinal respiratory activity. Abstract Cervical spinal injury interrupts bulbospinal pathways and results in cessation of phrenic bursting ipsilateral to the lesion. The ipsilateral phrenic activity can partially recover over weeks to months following injury due to the activation of latent crossed spinal pathways and exhibits a greater capacity to increase activity during respiratory challenges than the contralateral phrenic nerve. However, whether the bilateral phrenic nerves demonstrate differential responses to respiratory inhibitory inputs is unclear. Accordingly, the present study examined bilateral phrenic bursting in response to capsaicin‐induced pulmonary chemoreflexes, a robust respiratory inhibitory stimulus. Bilateral phrenic nerve activity was recorded in anaesthetized and mechanically ventilated adult rats at 8–9 weeks after C2 hemisection (C2Hx) or C2 laminectomy. Intra‐jugular capsaicin (1.5 μg kg−1) injection was performed to activate the bronchopulmonary C‐fibres to evoke pulmonary chemoreflexes. The present results indicate that capsaicin‐induced prolongation of expiratory duration was significantly attenuated in C2Hx

Phrenic motor outputs in response to bronchopulmonary C-fibre activation following chronic cervical spinal cord injury.

Science.gov (United States)

Lee, Kun-Ze

2016-10-15

Activation of bronchopulmonary C-fibres, the main chemosensitive afferents in the lung, can induce pulmonary chemoreflexes to modulate respiratory activity. Following chronic cervical spinal cord injury, bronchopulmonary C-fibre activation-induced inhibition of phrenic activity was exaggerated. Supersensitivity of phrenic motor outputs to the inhibitory effect of bronchopulmonary C-fibre activation is due to a shift of phrenic motoneuron types and slow recovery of phrenic motoneuron discharge in cervical spinal cord-injured animals. These data suggest that activation of bronchopulmonary C-fibres may retard phrenic output recovery following cervical spinal cord injury. The alteration of phenotype and discharge pattern of phrenic motoneuron enables us to understand the impact of spinal cord injury on spinal respiratory activity. Cervical spinal injury interrupts bulbospinal pathways and results in cessation of phrenic bursting ipsilateral to the lesion. The ipsilateral phrenic activity can partially recover over weeks to months following injury due to the activation of latent crossed spinal pathways and exhibits a greater capacity to increase activity during respiratory challenges than the contralateral phrenic nerve. However, whether the bilateral phrenic nerves demonstrate differential responses to respiratory inhibitory inputs is unclear. Accordingly, the present study examined bilateral phrenic bursting in response to capsaicin-induced pulmonary chemoreflexes, a robust respiratory inhibitory stimulus. Bilateral phrenic nerve activity was recorded in anaesthetized and mechanically ventilated adult rats at 8-9 weeks after C2 hemisection (C2Hx) or C2 laminectomy. Intra-jugular capsaicin (1.5 μg kg -1 ) injection was performed to activate the bronchopulmonary C-fibres to evoke pulmonary chemoreflexes. The present results indicate that capsaicin-induced prolongation of expiratory duration was significantly attenuated in C2Hx animals. However, ipsilateral phrenic

Quantitative assessment of integrated phrenic nerve activity.

Science.gov (United States)

Nichols, Nicole L; Mitchell, Gordon S

2016-06-01

Integrated electrical activity in the phrenic nerve is commonly used to assess within-animal changes in phrenic motor output. Because of concerns regarding the consistency of nerve recordings, activity is most often expressed as a percent change from baseline values. However, absolute values of nerve activity are necessary to assess the impact of neural injury or disease on phrenic motor output. To date, no systematic evaluations of the repeatability/reliability have been made among animals when phrenic recordings are performed by an experienced investigator using standardized methods. We performed a meta-analysis of studies reporting integrated phrenic nerve activity in many rat groups by the same experienced investigator; comparisons were made during baseline and maximal chemoreceptor stimulation in 14 wild-type Harlan and 14 Taconic Sprague Dawley groups, and in 3 pre-symptomatic and 11 end-stage SOD1(G93A) Taconic rat groups (an ALS model). Meta-analysis results indicate: (1) consistent measurements of integrated phrenic activity in each sub-strain of wild-type rats; (2) with bilateral nerve recordings, left-to-right integrated phrenic activity ratios are ∼1.0; and (3) consistently reduced activity in end-stage SOD1(G93A) rats. Thus, with appropriate precautions, integrated phrenic nerve activity enables robust, quantitative comparisons among nerves or experimental groups, including differences caused by neuromuscular disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Intermittent hypercapnia-induced phrenic long-term depression is revealed after serotonin receptor blockade with methysergide in anaesthetized rats.

Science.gov (United States)

Valic, Maja; Pecotic, Renata; Pavlinac Dodig, Ivana; Valic, Zoran; Stipica, Ivona; Dogas, Zoran

2016-02-01

What is the central question of this study? Intermittent hypercapnia is a concomitant feature of breathing disorders. Hypercapnic stimuli evoke a form of respiratory plasticity known as phrenic long-term depression in experimental animals. This study was performed to investigate the putative role of serotonin receptors in the initiation of phrenic long-term depression in anaesthetized rats. What is the main finding and its importance? Phrenic nerve long-term depression was revealed in animals pretreated with the serotonin broad-spectrum antagonist, methysergide. This study highlights that serotonin receptors modulate respiratory plasticity evoked by acute intermittent hypercapnia in anaesthetized rats. This study was performed to test the hypothesis that intermittent hypercapnia can evoke a form of respiratory plasticity known as long-term depression of the phrenic nerve (pLTD) and that 5-HT receptors play a role in the initiation of pLTD. Adult male urethane-anaesthetized, vagotomized, paralysed, mechanically ventilated Sprague-Dawley rats were exposed to an acute intermittent hypercapnia protocol. One group received i.v. injection of the non-selective 5-HT receptor antagonist methysergide and another group received i.v. injection of the selective 5-HT1A receptor antagonist WAY-100635 20 min before exposure to intermittent hypercapnia. A control group received i.v. injection of saline. Peak phrenic nerve activity and respiratory rhythm parameters were analysed at baseline (T0), during each of five hypercapnic episodes, and 15, 30 and 60 min (T60) after the last hypercapnia. Intravenous injection of methysergide before exposure to acute intermittent hypercapnia induced development of amplitude pLTD at T60 (decreased by 46.1 ± 6.9%, P = 0.003). Conversely, in control and WAY-100635-pretreated animals, exposure to acute intermittent hypercapnia did not evoke amplitude pLTD. However, a long-term decrease in phrenic nerve frequency was evoked both in control (42 ± 4

The prognostic value of concurrent phrenic nerve palsy in newborn babies with neonatal brachial plexus palsy.

Science.gov (United States)

Yoshida, Kiyoshi; Kawabata, Hidehiko

2015-06-01

To investigate the prognostic value of concurrent phrenic nerve palsy for predicting spontaneous motor recovery in neonatal brachial plexus palsy. We reviewed the records of 366 neonates with brachial plexus palsy. The clinical and follow-up data of patients with and without phrenic nerve palsy were compared. Of 366 newborn babies with neonatal brachial plexus palsy, 21 (6%) had concurrent phrenic nerve palsy. Sixteen of these neonates had upper-type palsy and 5 had total-type palsy. Poor spontaneous motor recovery was observed in 13 neonates with concurrent phrenic nerve palsy (62%) and in 129 without concurrent phrenic nerve palsy (39%). Among neonates born via vertex delivery, poor motor recovery was observed in 7 of 9 (78%) neonates with concurrent phrenic nerve palsy and 115 of 296 (39%) without concurrent phrenic nerve palsy. Concurrent phrenic nerve palsy in neonates with brachial plexus palsy has prognostic value in predicting poor spontaneous motor recovery of the brachial plexus, particularly after vertex delivery. Therapeutic IV. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Cervical spinal demyelination with ethidium bromide impairs respiratory (phrenic) activity and forelimb motor behavior in rats

Science.gov (United States)

Nichols, Nicole L.; Punzo, Antonio M.; Duncan, Ian D.; Mitchell, Gordon S.; Johnson, Rebecca A.

2012-01-01

Although respiratory complications are a major cause of morbidity/mortality in many neural injuries or diseases, little is known concerning mechanisms whereby deficient myelin impairs breathing, or how patients compensate for such changes. Here, we tested the hypothesis that respiratory and forelimb motor function are impaired in a rat model of focal dorsolateral spinal demyelination (ethidium bromide, EB). Ventilation, phrenic nerve activity and horizontal ladder walking were performed 7-14 days post-C2 injection of EB or vehicle (SHAM). EB caused dorsolateral demyelination at C2-C3 followed by signficant spontaneous remyelination at 14 days post-EB. Although ventilation did not differ between groups, ipsilateral integrated phrenic nerve burst amplitude was significantly reduced versus SHAM during chemoreceptor activation at 7 days post-EB but recovered by 14 days. The ratio of ipsi- to contralateral phrenic nerve amplitude correlated with cross-sectional lesion area. This ratio was significantly reduced 7 days post-EB versus SHAM during baseline conditions, and versus SHAM and 14 day groups during chemoreceptor activation. Limb function ipsilateral to EB was impaired 7 days post-EB and partially recovered by 14 days post-EB. EB provides a reversible model of focal, spinal demyelination, and may be a useful model to study mechanisms of functional impairment and recovery via motor plasticity, or the efficacy of new therapeutic interventions to reduce severity or duration of disease. PMID:23159317

The importance of phrenic nerve preservation and its effect on long-term postoperative lung function after pneumonectomy.

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Kocher, Gregor J; Poulson, Jannie Lysgaard; Blichfeldt-Eckhardt, Morten Rune; Elle, Bo; Schmid, Ralph A; Licht, Peter B

2016-04-01

The importance of phrenic nerve preservation during pneumonectomy remains controversial. We previously demonstrated that preservation of the phrenic nerve in the immediate postoperative period preserved lung function by 3-5% but little is known about its long-term effects. We, therefore, decided to investigate the effect of temporary ipsilateral cervical phrenic nerve block on dynamic lung volumes in mid- to long-term pneumonectomy patients. We investigated 14 patients after a median of 9 years post pneumonectomy (range: 1-15 years). Lung function testing (spirometry) and fluoroscopic and/or sonographic assessment of diaphragmatic motion on the pneumonectomy side were performed before and after ultrasonographic-guided ipsilateral cervical phrenic nerve block by infiltration with lidocaine. Ipsilateral phrenic nerve block was successfully achieved in 12 patients (86%). In the remaining 2 patients, diaphragmatic motion was already paradoxical before the nerve block. We found no significant difference on dynamic lung function values (FEV1 'before' 1.39 ± 0.44 vs FEV1 'after' 1.38 ± 0.40; P = 0.81). Induction of a temporary diaphragmatic palsy did not significantly influence dynamic lung volumes in mid- to long-term pneumonectomy patients, suggesting that preservation of the phrenic nerve is of greater importance in the immediate postoperative period after pneumonectomy. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Anatomical feasibility of vagus nerve esophageal branch transfer to the phrenic nerve☆

Science.gov (United States)

Wang, Ce; Liu, Jun; Yuan, Wen; Zhou, Xuhui; Wang, Xinwei; Xu, Peng; Chen, Jian; Wu, Guoxin; Shi, Sheng

2012-01-01

This study measured the vagus and phrenic nerves from 12 adult cadavers. We found that the width and thickness of the vagus and phrenic nerves were different in the chest. The distance from the point of the vagus nerve and phrenic nerve on the plane of the inferior border of portal pulmonary arteries (T point) was approximately 7 cm to the diaphragm and was approximately 10 cm to the clavicle level. The number of motor fibers in the vagus nerves was 1 716 ± 362, and the number of nerve fibers was 4 473 ± 653. The number of motor fibers in the phrenic nerves ranged from 3 078 ± 684 to 4 794 ± 638, and the number of nerve fibers ranged from 3 437 ± 642 to 5 071 ± 723. No significant difference was found in the total number of nerve fibers. The results suggest that width, thickness, and total number of nerve fibers are similar between the vagus and phrenic nerves, but the number of motor fibers is different between them. PMID:25745467

Phrenic motoneurons: output elements of a highly organized intraspinal network.

Science.gov (United States)

Ghali, Michael George Zaki

2018-03-01

pontomedullary respiratory network generates the respiratory pattern and relays it to bulbar and spinal respiratory motor outputs. The phrenic motor system controlling diaphragm contraction receives and processes descending commands to produce orderly, synchronous, and cycle-to-cycle-reproducible spatiotemporal firing. Multiple investigators have studied phrenic motoneurons (PhMNs) in an attempt to shed light on local mechanisms underlying phrenic pattern formation. I and colleagues (Marchenko V, Ghali MG, Rogers RF. Am J Physiol Regul Integr Comp Physiol 308: R916-R926, 2015.) recorded PhMNs in unanesthetized, decerebrate rats and related their activity to simultaneous phrenic nerve (PhN) activity by creating a time-frequency representation of PhMN-PhN power and coherence. On the basis of their temporal firing patterns and relationship to PhN activity, we categorized PhMNs into three classes, each of which emerges as a result of intrinsic biophysical and network properties and organizes the orderly contraction of diaphragm motor fibers. For example, early inspiratory diaphragmatic activation by the early coherent burst generated by high-frequency PhMNs may be necessary to prime it to overcome its initial inertia. We have also demonstrated the existence of a prominent role for local intraspinal inhibitory mechanisms in shaping phrenic pattern formation. The objective of this review is to relate and synthesize recent findings with those of previous studies with the aim of demonstrating that the phrenic nucleus is a region of active local processing, rather than a passive relay of descending inputs.

The pattern and extent of retrograde transsynaptic transport of WGA-Alexa 488 in the phrenic motor system is dependent upon the site of application.

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Goshgarian, Harry G; Buttry, Janelle L

2014-01-30

The first aim of the study was to determine if WGA-Alexa 488 would undergo retrograde transsynaptic transport in the phrenic motor system as we have shown with WGA-HRP in a previous study. The advantage of using WGA-Alexa 488 is that labeled neurons could be isolated and analyzed for intracellular molecular mechanisms without exposing tissue sections to chemicals for histochemical staining. The second aim of the study was to investigate the pattern and extent of labeling that occurs when WGA-Alexa 488 is applied to the cervical phrenic nerve as compared to intradiaphragmatic injection. After injecting the hemidiaphragm ipsilateral to a C2 spinal cord hemisection, WGA-Alexa 488 presumably diffused to the contralateral hemidiaphragm and labeled the phrenic nuclei bilaterally. In all animals with hemidiaphragmatic injection, the rostral ventral respiratory group (rVRG) was also labeled bilaterally in the medulla. Thus, injection of WGA-Alexa 488 into the diaphragm results in retrograde transsynaptic transport in the phrenic motor system. After applying WGA-Alexa 488 to the ipsilateral intact cervical phrenic nerve in both C2 hemisected rats and rats with a sham hemisection, only ipsilateral phrenic neurons were labeled; there was no labeling of the rVRG or any other center in the medulla. These results suggest that WGA-Alexa 488 must be applied in the vicinity of the phrenic myoneural junction where there is a high concentration of WGA receptors in order for transsynaptic transport to occur. The present study provides investigators with a new tool to study plasticity in the respiratory system after spinal cord injury. Copyright © 2013. Published by Elsevier B.V.

Intermittent apnea elicits inactivity-induced phrenic motor facilitation via a retinoic acid- and protein synthesis-dependent pathway.

Science.gov (United States)

Baertsch, Nathan A; Baker, Tracy L

2017-11-01

Respiratory motoneuron pools must provide rhythmic inspiratory drive that is robust and reliable, yet dynamic enough to respond to respiratory challenges. One form of plasticity that is hypothesized to contribute to motor output stability by sensing and responding to inadequate respiratory neural activity is inactivity-induced phrenic motor facilitation (iPMF), an increase in inspiratory output triggered by a reduction in phrenic synaptic inputs. Evidence suggests that mechanisms giving rise to iPMF differ depending on the pattern of reduced respiratory neural activity (i.e., neural apnea). A prolonged neural apnea elicits iPMF via a spinal TNF-α-induced increase in atypical PKC activity, but little is known regarding mechanisms that elicit iPMF following intermittent neural apnea. We tested the hypothesis that iPMF triggered by intermittent neural apnea requires retinoic acid and protein synthesis. Phrenic nerve activity was recorded in urethane-anesthetized and -ventilated rats treated intrathecally with an inhibitor of retinoic acid synthesis (4-diethlyaminobenzaldehyde, DEAB), a protein synthesis inhibitor (emetine), or vehicle (artificial cerebrospinal fluid) before intermittent (5 episodes, ~1.25 min each) or prolonged (30 min) neural apnea. Both DEAB and emetine abolished iPMF elicited by intermittent neural apnea but had no effect on iPMF elicited by a prolonged neural apnea. Thus different patterns of reduced respiratory neural activity elicit phenotypically similar iPMF via distinct spinal mechanisms. Understanding mechanisms that allow respiratory motoneurons to dynamically tune their output may have important implications in the context of respiratory control disorders that involve varied patterns of reduced respiratory neural activity, such as central sleep apnea and spinal cord injury. NEW & NOTEWORTHY We identify spinal retinoic acid and protein synthesis as critical components in the cellular cascade whereby repetitive reductions in respiratory

Neurotization of the phrenic nerve with accessory nerve for high cervical spinal cord injury with respiratory distress: an anatomic study.

Science.gov (United States)

Wang, Ce; Zhang, Ying; Nicholas, Tsai; Wu, Guoxin; Shi, Sheng; Bo, Yin; Wang, Xinwei; Zhou, Xuhui; Yuan, Wen

2014-01-01

High cervical spinal cord injury is associated with high morbidity and mortality. Traditional treatments carry various complications such as infection, pacemaker failure and undesirable movement. Thus, a secure surgical strategy with fewer complications analogous to physiological ventilation is still required. We hope to offer one potential method to decrease the complications and improve survival qualities of patients from the aspect of anatomy. The purpose of the study is to provide anatomic details on the accessory nerve and phrenic nerve for neurotization in patients with high spinal cord injuries. 38 cadavers (76 accessory and 76 phrenic nerves) were dissected in the study. The width, length and thickness of each accessory nerve and phrenic nerve above clavicle were measured. The distances from several landmarks on accessory nerve to the origin and the end of the phrenic nerve above clavicle were measured too. Then, the number of motor nerve fibers on different sections of the nerves was calculated using the technique of immunohistochemistry. The accessory nerves distal to its sternocleidomastoid muscular branches were 1.52 ± 0.32 mm ~1.54 ± 0.29 mm in width, 0.52 ± 0.18 mm ~ 0.56 ± 0.20mm in thickness and 9.52 ± 0.98 cm in length. And the phrenic nerves above clavicle were 1.44 ± 0.23 mm ~ 1.45 ± 0.24 mm in width, 0.47 ± 0.15 mm ~ 0.56 ± 0.25 mm in thickness and 6.48 ± 0.78 cm in length. The distance between the starting point of accessory nerve and phrenic nerve were 3.24 ± 1.17 cm, and the distance between the starting point of accessory nerve and the end of the phrenic nerve above clavicle were 8.72 ± 0.84 cm. The numbers of motor nerve fibers in accessory nerve were 1,038 ± 320~1,102 ± 216, before giving out the sternocleidomastoid muscular branches. The number of motor nerve fibers in the phrenic nerve was 911 ± 321~1,338 ± 467. The accessory nerve and the phrenic were similar in width, thickness and the number of motor nerve fibers. And

Acetazolamide on the ventral medulla of the cat increases phrenic output and delays the ventilatory response to CO sub 2

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Coates, E.L.; Aihua Li; Nattie, E.E. (Dartmouth College, Hanover, NH (United States))

1991-03-11

Acetazolamide applied to the surface of the rostral ventrolateral medulla or microinjected beneath the medullary surface in chloralose-urethan-anesthetized, vagotomized, carotid denervated, paralyzed, servo-ventilated cats produced a long-lasting increase in phrenic minute ventilation. Extracellular pH measured beneath the rostral ventrolateral medulla exhibited a long-lasting decrease after surface acetazolamide but was not a good predictor, in each individual animal, of changes in phrenic activity. Medullary carbonic anhydrase inhibition reduced the slope and the half-time of the phrenic response to rapid step CO{sub 2} increases. Conversely, acetazolamide did not effect the phrenic response to steady state CO{sub 2} increases. These data indicate that localized inhibition of medullary carbonic anhydrase causes a centrally mediated increase in ventilation that the authors attribute to medullary tissue acidosis. In addition, these data indicate that medullary carbonic anhydrase may play a role in central CO{sub 2} chemotransduction.

Intermittent reductions in respiratory neural activity elicit spinal TNF-α-independent, atypical PKC-dependent inactivity-induced phrenic motor facilitation.

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Baertsch, Nathan A; Baker-Herman, Tracy L

2015-04-15

In many neural networks, mechanisms of compensatory plasticity respond to prolonged reductions in neural activity by increasing cellular excitability or synaptic strength. In the respiratory control system, a prolonged reduction in synaptic inputs to the phrenic motor pool elicits a TNF-α- and atypical PKC-dependent form of spinal plasticity known as inactivity-induced phrenic motor facilitation (iPMF). Although iPMF may be elicited by a prolonged reduction in respiratory neural activity, iPMF is more efficiently induced when reduced respiratory neural activity (neural apnea) occurs intermittently. Mechanisms giving rise to iPMF following intermittent neural apnea are unknown. The purpose of this study was to test the hypothesis that iPMF following intermittent reductions in respiratory neural activity requires spinal TNF-α and aPKC. Phrenic motor output was recorded in anesthetized and ventilated rats exposed to brief intermittent (5, ∼1.25 min), brief sustained (∼6.25 min), or prolonged sustained (30 min) neural apnea. iPMF was elicited following brief intermittent and prolonged sustained neural apnea, but not following brief sustained neural apnea. Unlike iPMF following prolonged neural apnea, spinal TNF-α was not required to initiate iPMF during intermittent neural apnea; however, aPKC was still required for its stabilization. These results suggest that different patterns of respiratory neural activity induce iPMF through distinct cellular mechanisms but ultimately converge on a similar downstream pathway. Understanding the diverse cellular mechanisms that give rise to inactivity-induced respiratory plasticity may lead to development of novel therapeutic strategies to treat devastating respiratory control disorders when endogenous compensatory mechanisms fail. Copyright © 2015 the American Physiological Society.

Long-Term Follow-Up after Phrenic Nerve Reconstruction for Diaphragmatic Paralysis: A Review of 180 Patients.

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Kaufman, Matthew R; Elkwood, Andrew I; Brown, David; Cece, John; Martins, Catarina; Bauer, Thomas; Weissler, Jason; Rezzadeh, Kameron; Jarrahy, Reza

2017-01-01

Background  Phrenic nerve reconstruction has been evaluated as a method of restoring functional activity and may be an effective alternative to diaphragm plication. Longer follow-up and a larger cohort for analysis are necessary to confirm the efficacy of this procedure for diaphragmatic paralysis. Methods  A total of 180 patients treated with phrenic nerve reconstruction for chronic diaphragmatic paralysis were followed for a median 2.7 years. Assessment parameters included: 36-Item Short Form Health Survey (SF-36) physical functioning survey, spirometry, chest fluoroscopy, electrodiagnostic evaluation, a five-item questionnaire to assess specific functional issues, and overall patient-reported outcome. Results  Overall, 134 males and 46 females with an average age of 56 years (range: 10-79 years) were treated. Mean baseline percent predicted values for forced expiratory volume in 1 second, forced vital capacity, vital capacity, and total lung capacity, were 61, 63, 67, and 75%, respectively. The corresponding percent improvements in percent predicted values were: 11, 6, 9, and 13% ( p ≤ 0.01; ≤ 0.01; ≤ 0.05; ≤ 0.01). Mean preoperative SF-36 physical functioning survey scores were 39%, and an improvement to 65% was demonstrated following surgery ( p  ≤ 0.0001). Nerve conduction latency, improved by an average 23% ( p  ≤ 0.005), and there was a corresponding 125% increase in diaphragm motor amplitude ( p  ≤ 0.0001). A total of 89% of patients reported an overall improvement in breathing function. Conclusion  Long-term assessment of phrenic nerve reconstruction for diaphragmatic paralysis indicates functional correction and symptomatic relief. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Severe acute intermittent hypoxia elicits phrenic long-term facilitation by a novel adenosine-dependent mechanism

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Nichols, Nicole L.; Dale, Erica A.

2012-01-01

Acute intermittent hypoxia [AIH; 3, 5-min episodes; 35–45 mmHg arterial Po2 (PaO2)] elicits serotonin-dependent phrenic long-term facilitation (pLTF), a form of phrenic motor facilitation (pMF) initiated by Gq protein-coupled metabotropic 5-HT2 receptors. An alternate pathway to pMF is induced by Gs protein-coupled metabotropic receptors, including adenosine A2A receptors. AIH-induced pLTF is dominated by the serotonin-dependent pathway and is actually restrained via inhibition from the adenosine-dependent pathway. Here, we hypothesized that severe AIH shifts pLTF from a serotonin-dependent to an adenosine-dependent form of pMF. pLTF induced by severe (25–30 mmHg PaO2) and moderate (45–55 mmHg PaO2) AIH were compared in anesthetized rats, with and without intrathecal (C4) spinal A2A (MSX-3, 130 ng/kg, 12 μl) or 5-HT receptor antagonist (methysergide, 300 μg/kg, 15 μl) injections. During severe, but not moderate AIH, progressive augmentation of the phrenic response during hypoxic episodes was observed. Severe AIH (78% ± 8% 90 min post-AIH, n = 6) elicited greater pLTF vs. moderate AIH (41% ± 12%, n = 8; P MSX-3 (28% ± 6%; n = 6; P 0.05). Thus severe AIH shifts pLTF from a serotonin-dependent to an adenosine-dependent mechanism; the adenosinergic pathway inhibits the serotonergic pathway following moderate AIH. Here we demonstrate a novel adenosine-dependent pathway to pLTF following severe AIH. Shifts in the mechanisms of respiratory plasticity provide the ventilatory control system greater flexibility as challenges that differ in severity are confronted. PMID:22403346

Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

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Ying Liu

2015-01-01

Full Text Available Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ′excellent′ and ′good′ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.

Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics.

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Liu, Ying; Xu, Xun-Cheng; Zou, Yi; Li, Su-Rong; Zhang, Bin; Wang, Yue

2015-02-01

Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering 'excellent' and 'good' muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.

Targeted Delivery of TrkB Receptor to Phrenic Motoneurons Enhances Functional Recovery of Rhythmic Phrenic Activity after Cervical Spinal Hemisection

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Gransee, Heather M.; Zhan, Wen-Zhi; Sieck, Gary C.; Mantilla, Carlos B.

2013-01-01

Progressive recovery of rhythmic phrenic activity occurs over time after a spinal cord hemisection involving unilateral transection of anterolateral funiculi at C2 (SH). Brain-derived neurotrophic factor (BDNF) acting through its full-length tropomyosin related kinase receptor subtype B (TrkB.FL) contributes to neuroplasticity after spinal cord injury, but the specific cellular substrates remain unclear. We hypothesized that selectively targeting increased TrkB.FL expression to phrenic motoneurons would be sufficient to enhance recovery of rhythmic phrenic activity after SH. Several adeno-associated virus (AAV) serotypes expressing GFP were screened to determine specificity for phrenic motoneuron transduction via intrapleural injection in adult rats. GFP expression was present in the cervical spinal cord 3 weeks after treatment with AAV serotypes 7, 8, and 9, but not with AAV2, 6, or rhesus-10. Overall, AAV7 produced the most consistent GFP expression in phrenic motoneurons. SH was performed 3 weeks after intrapleural injection of AAV7 expressing human TrkB.FL-FLAG or saline. Delivery of TrkB.FL-FLAG to phrenic motoneurons was confirmed by FLAG protein expression in the phrenic motor nucleus and human TrkB.FL mRNA expression in microdissected phrenic motoneurons. In all SH rats, absence of ipsilateral diaphragm EMG activity was confirmed at 3 days post-SH, verifying complete interruption of ipsilateral descending drive to phrenic motoneurons. At 14 days post-SH, all AAV7-TrkB.FL treated rats (n = 11) displayed recovery of ipsilateral diaphragm EMG activity compared to 3 out of 8 untreated SH rats (pphrenic motoneurons is sufficient to enhance recovery of ipsilateral rhythmic phrenic activity after SH, indicating that selectively targeting gene expression in spared motoneurons below the level of spinal cord injury may promote functional recovery. PMID:23724091

Anatomical Recruitment of Spinal V2a Interneurons into Phrenic Motor Circuitry after High Cervical Spinal Cord Injury.

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Zholudeva, Lyandysha V; Karliner, Jordyn S; Dougherty, Kimberly J; Lane, Michael A

2017-11-01

More than half of all spinal cord injuries (SCIs) occur at the cervical level, often resulting in impaired respiration. Despite this devastating outcome, there is substantial evidence for endogenous neuroplasticity after cervical SCI. Spinal interneurons are widely recognized as being an essential anatomical component of this plasticity by contributing to novel neuronal pathways that can result in functional improvement. The identity of spinal interneurons involved with respiratory plasticity post-SCI, however, has remained largely unknown. Using a transgenic Chx10-eGFP mouse line (Strain 011391-UCD), the present study is the first to demonstrate the recruitment of excitatory interneurons into injured phrenic circuitry after a high cervical SCI. Diaphragm electromyography and anatomical analysis were used to confirm lesion-induced functional deficits and document extent of the lesion, respectively. Transneuronal tracing with pseudorabies virus (PRV) was used to identify interneurons within the phrenic circuitry. There was a robust increase in the number of PRV-labeled V2a interneurons ipsilateral to the C2 hemisection, demonstrating that significant numbers of these excitatory spinal interneurons were anatomically recruited into the phrenic motor pathway two weeks after injury, a time known to correspond with functional phrenic plasticity. Understanding this anatomical spinal plasticity and the neural substrates associated with functional compensation or recovery post-SCI in a controlled, experimental setting may help shed light onto possible cellular therapeutic candidates that can be targeted to enhance spontaneous recovery.

Histopathology of cryoballoon ablation-induced phrenic nerve injury.

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Andrade, Jason G; Dubuc, Marc; Ferreira, Jose; Guerra, Peter G; Landry, Evelyn; Coulombe, Nicolas; Rivard, Lena; Macle, Laurent; Thibault, Bernard; Talajic, Mario; Roy, Denis; Khairy, Paul

2014-02-01

Hemi-diaphragmatic paralysis is the most common complication associated with cryoballoon ablation for atrial fibrillation, yet the histopathology of phrenic nerve injury has not been well described. A preclinical randomized study was conducted to characterize the histopathology of phrenic nerve injury induced by cryoballoon ablation and assess the potential for electromyographic (EMG) monitoring to limit phrenic nerve damage. Thirty-two dogs underwent cryoballoon ablation of the right superior pulmonary vein with the objective of inducing phrenic nerve injury. Animals were randomized 1:1 to standard monitoring (i.e., interruption of ablation upon reduction in diaphragmatic motion) versus EMG guidance (i.e., cessation of ablation upon a 30% reduction in the diaphragmatic compound motor action potential [CMAP] amplitude). The acute procedural endpoint was achieved in all dogs. Phrenic nerve injury was characterized by Wallerian degeneration, with subperineural injury to large myelinated axons and evidence of axonal regeneration. The degree of phrenic nerve injury paralleled the reduction in CMAP amplitude (P = 0.007). Animals randomized to EMG guidance had a lower incidence of acute hemi-diaphragmatic paralysis (50% vs 100%; P = 0.001), persistent paralysis at 30 days (21% vs 75%; multivariate odds ratio 0.12, 95% confidence interval [0.02, 0.69], P = 0.017), and a lesser severity of histologic injury (P = 0.001). Mature pulmonary vein ablation lesion characteristics, including circumferentiality and transmurality, were similar in both groups. Phrenic nerve injury induced by cryoballoon ablation is axonal in nature and characterized by Wallerian degeneration, with potential for recovery. An EMG-guided approach is superior to standard monitoring in limiting phrenic nerve damage. © 2013 Wiley Periodicals, Inc.

Cryoablation of focal tachycardia originating from the right atrial free wall during upstream phrenic pacing to avoid phrenic nerve injury.

Science.gov (United States)

Johnsrude, Christopher

2015-01-01

Recognition of the potential for phrenic nerve injury (PNI) often prompts less aggressive attempts at catheter ablation of multiple forms of tachycardia or abandoning ablation altogether. Some novel techniques to avoid PNI during catheter ablation have been described. Five patients (age: 13-57 years, three females) with ectopic atrial tachycardia originating from the right atrial free wall (RAFW) near the phrenic nerve underwent electrophysiology study with three-dimensional mapping and endocardial cryoablation. Upstream phrenic pacing was performed after cryoadherence was achieved, and cryoablation of ectopic foci was performed during close observation for occurrence of PNI and tachycardia elimination. Cryoablation acutely eliminated five of six atrial tachycardias originating close to the phrenic nerve. Transient PNI during cryothermy occurred in two patients, and resolved within 3 minutes. Patients were observed overnight on telemetry, with no early recurrences of targeted atrial tachycardias and no evidence of PNI. At last follow-up of 1-39 months, four patients were arrhythmia free on no medications. Catheter cryoablation during simultaneous upstream phrenic nerve pacing can lead to safe and effective elimination of focal atrial tachycardias originating from the RAFW close to the phrenic nerve. ©2014 Wiley Periodicals, Inc.

Inhibition of protein kinase A activity depresses phrenic drive and glycinergic signalling, but not rhythmogenesis in anaesthetized rat.

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Burke, P G R; Sousa, L O; Tallapragada, V J; Goodchild, A K

2013-07-01

The cAMP-protein kinase A (PKA) pathway plays a critical role in regulating neuronal activity. Yet, how PKA signalling shapes the population activity of neurons that regulate respiratory rhythm and motor patterns in vivo is poorly defined. We determined the respiratory effects of focally inhibiting endogenous PKA activity in defined classes of respiratory neurons in the ventrolateral medulla and spinal cord by microinjection of the membrane-permeable PKA inhibitor Rp-adenosine 3',5'-cyclic monophosphothioate (Rp-cAMPS) in urethane-anaesthetized adult Sprague Dawley rats. Phrenic nerve activity, end-tidal CO2 and arterial pressure were recorded. Rp-cAMPS in the preBötzinger complex (preBötC) caused powerful, dose-dependent depression of phrenic burst amplitude and inspiratory period. Rp-cAMPS powerfully depressed burst amplitude in the phrenic premotor nucleus, but had no effect at the phrenic motor nucleus, suggesting a lack of persistent PKA activity here. Surprisingly, inhibition of PKA activity in the preBötC increased phrenic burst frequency, whereas in the Bötzinger complex phrenic frequency decreased. Pretreating the preBötC with strychnine, but not bicuculline, blocked the Rp-cAMPS-evoked increase in frequency, but not the depression of phrenic burst amplitude. We conclude that endogenous PKA activity in excitatory inspiratory preBötzinger neurons and phrenic premotor neurons, but not motor neurons, regulates network inspiratory drive currents that underpin the intensity of phrenic nerve discharge. We show that inhibition of PKA activity reduces tonic glycinergic transmission that normally restrains the frequency of rhythmic respiratory activity. Finally, we suggest that the maintenance of the respiratory rhythm in vivo is not dependent on endogenous cAMP-PKA signalling. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Neural control of phrenic motoneuron discharge

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Lee, Kun-Ze; Fuller, David D.

2011-01-01

Phrenic motoneurons (PMNs) provide a synaptic relay between bulbospinal respiratory pathways and the diaphragm muscle. PMNs also receive propriospinal inputs, although the functional role of these interneuronal projections has not been established. Here we review the literature regarding PMN discharge patterns during breathing and the potential mechanisms that underlie PMN recruitment. Anatomical and neurophysiological studies indicate that PMNs form a heterogeneous pool, with respiratory-related PMN discharge and recruitment patterns likely determined by a balance between intrinsic MN properties and extrinsic synaptic inputs. We also review the limited literature regarding PMN bursting during respiratory plasticity. Differential recruitment or rate modulation of PMN subtypes may underlie phrenic motor plasticity following neural injury and/or respiratory stimulation; however this possibility remains relatively unexplored. PMID:21376841

Phrenic motoneuron discharge patterns following chronic cervical spinal cord injury

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Lee, Kun-Ze; Dougherty, Brendan J.; Sandhu, Milapjit S.; Lane, Michael A.; Reier, Paul J.; Fuller, David D.

2013-01-01

Cervical spinal cord injury (SCI) dramatically disrupts synaptic inputs and triggers biochemical, as well as morphological, plasticity in relation to the phrenic motor neuron (PhMN) pool. Accordingly, our primary purpose was to determine if chronic SCI induces fundamental changes in the recruitment profile and discharge patterns of PhMNs. Individual PhMN action potentials were recorded from the phrenic nerve ipsilateral to lateral cervical (C2) hemisection injury (C2Hx) in anesthetized adult male rats at 2, 4 or 8 wks post-injury and in uninjured controls. PhMNs were phenotypically classified as early (Early-I) or late inspiratory (Late-I), or silent according to discharge patterns. Following C2Hx, the distribution of PhMNs was dominated by Late-I and silent cells. Late-I burst parameters (e.g., spikes per breath, burst frequency and duration) were initially reduced but returned towards control values by 8 wks post-injury. In addition, a unique PhMN burst pattern emerged after C2Hx in which Early-I cells burst tonically during hypocapnic inspiratory apnea. We also quantified the impact of gradual reductions in end-tidal CO2 partial pressure (PETCO2) on bilateral phrenic nerve activity. Compared to control rats, as PETCO2 declined, the C2Hx animals had greater inspiratory frequencies (breaths*min−1) and more substantial decreases in ipsilateral phrenic burst amplitude. We conclude that the primary physiological impact of C2Hx on ipsilateral PhMN burst patterns is a persistent delay in burst onset, transient reductions in burst frequency, and the emergence of tonic burst patterns. The inspiratory frequency data suggest that plasticity in brainstem networks is likely to play an important role in phrenic motor output after cervical SCI. PMID:23954215

Phrenic motoneuron discharge patterns following chronic cervical spinal cord injury.

Science.gov (United States)

Lee, Kun-Ze; Dougherty, Brendan J; Sandhu, Milapjit S; Lane, Michael A; Reier, Paul J; Fuller, David D

2013-11-01

Cervical spinal cord injury (SCI) dramatically disrupts synaptic inputs and triggers biochemical, as well as morphological, plasticity in relation to the phrenic motor neuron (PhMN) pool. Accordingly, our primary purpose was to determine if chronic SCI induces fundamental changes in the recruitment profile and discharge patterns of PhMNs. Individual PhMN action potentials were recorded from the phrenic nerve ipsilateral to lateral cervical (C2) hemisection injury (C2Hx) in anesthetized adult male rats at 2, 4 or 8 wks post-injury and in uninjured controls. PhMNs were phenotypically classified as early (Early-I) or late inspiratory (Late-I), or silent according to discharge patterns. Following C2Hx, the distribution of PhMNs was dominated by Late-I and silent cells. Late-I burst parameters (e.g., spikes per breath, burst frequency and duration) were initially reduced but returned towards control values by 8wks post-injury. In addition, a unique PhMN burst pattern emerged after C2Hx in which Early-I cells burst tonically during hypocapnic inspiratory apnea. We also quantified the impact of gradual reductions in end-tidal CO2 partial pressure (PETCO2) on bilateral phrenic nerve activity. Compared to control rats, as PETCO2 declined, the C2Hx animals had greater inspiratory frequencies (breaths∗min(-1)) and more substantial decreases in ipsilateral phrenic burst amplitude. We conclude that the primary physiological impact of C2Hx on ipsilateral PhMN burst patterns is a persistent delay in burst onset, transient reductions in burst frequency, and the emergence of tonic burst patterns. The inspiratory frequency data suggest that plasticity in brainstem networks is likely to play an important role in phrenic motor output after cervical SCI. © 2013.

Phrenic Nerve Conduction Abnormalities Correlate with Diaphragmatic Descent in Chronic Obstructive Pulmonary Disease.

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El-Tantawi, Gihan A Younis; Imam, Mohamed H; Morsi, Tamer S

2015-01-01

Diaphragmatic weakness in chronic obstructive pulmonary disease (COPD) is ascribed to hyperinflation-induced diaphragm shortening as well as impairment in cellular and subcellular structures. Although phrenic neuropathy is known to cause diaphragmatic weakness, phrenic neuropathy is rarely considered in COPD. This work aimed at assessing phrenic nerve conduction in COPD and its relation to radiographic hyperinflation and pulmonary function. Forty COPD patients were evaluated. Radiographic parameters of lung hyperinflation were measured on postero-anterior and lateral chest x-ray films. Flow volume loop parameters were obtained from all patients. Motor conduction study of the phrenic nerves was performed and potentials were recorded over the xiphoid process and the ipsilateral 7th intercostal space. Twenty-seven healthy subjects were enrolled as controls. Parameters of phrenic nerve conduction differed significantly in patients compared to controls. Phrenic nerve abnormalities were detected in 17 patients (42.5%). Electrophysiological measures correlated with diaphragmatic angle of depression on lateral view films and with lung height on postero-anterior films. They did not correlate with the flow volume loop data or disease severity score. Phrenic nerve conduction abnormality is an appreciated finding in COPD. Nerve stretching associated with diaphragmatic descent can be a suggested mechanism for nerve lesion. The presence of phrenic neuropathy may be an additional contributing factor to diaphragmatic dysfunction in COPD patients.

Periodicity during hypercapnic and hypoxic stimulus is crucial in distinct aspects of phrenic nerve plasticity.

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Stipica, I; Pavlinac Dodig, I; Pecotic, R; Dogas, Z; Valic, Z; Valic, M

2016-01-01

This study was undertaken to determine pattern sensitivity of phrenic nerve plasticity in respect to different respiratory challenges. We compared long-term effects of intermittent and continuous hypercapnic and hypoxic stimuli, and combined intermittent hypercapnia and hypoxia on phrenic nerve plasticity. Adult, male, urethane-anesthetized, vagotomized, paralyzed, mechanically ventilated Sprague-Dawley rats were exposed to: acute intermittent hypercapnia (AIHc or AIHc(O2)), acute intermittent hypoxia (AIH), combined intermittent hypercapnia and hypoxia (AIHcH), continuous hypercapnia (CHc), or continuous hypoxia (CH). Peak phrenic nerve activity (pPNA) and burst frequency were analyzed during baseline (T0), hypercapnia or hypoxia exposures, at 15, 30, and 60 min (T60) after the end of the stimulus. Exposure to acute intermittent hypercapnia elicited decrease of phrenic nerve frequency from 44.25+/-4.06 at T0 to 35.29+/-5.21 at T60, (P=0.038, AIHc) and from 45.5+/-2.62 to 37.17+/-3.68 breaths/min (P=0.049, AIHc(O2)), i.e. frequency phrenic long term depression was induced. Exposure to AIH elicited increase of pPNA at T60 by 141.0+/-28.2 % compared to baseline (P=0.015), i.e. phrenic long-term facilitation was induced. Exposure to AIHcH, CHc, or CH protocols failed to induce long-term plasticity of the phrenic nerve. Thus, we conclude that intermittency of the hypercapnic or hypoxic stimuli is needed to evoke phrenic nerve plasticity.

Phrenic nerve neurotization utilizing the spinal accessory nerve: technical note with potential application in patients with high cervical quadriplegia.

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Tubbs, R Shane; Pearson, Blake; Loukas, Marios; Shokouhi, Ghaffar; Shoja, Mohammadali M; Oakes, W Jerry

2008-11-01

High cervical quadriplegia is associated with high morbidity and mortality. Artificial respiration in these patients carries significant long-term risks such as infection, atelectasis, and respiratory failure. As phrenic nerve pacing has been proven to free many of these patients from ventilatory dependency, we hypothesized that neurotization of the phrenic nerve with the spinal accessory nerve (SAN) may offer one potential alternative to phrenic nerve stimulation via pacing and may be more efficacious and longer lasting without the complications of an implantable device. Ten cadavers (20 sides) underwent exposure of the cervical phrenic nerve and the SAN in the posterior cervical triangle. The SAN was split into anterior and posterior halves and the anterior half transposed to the ipsilateral phrenic nerve as it crossed the anterior scalene muscle. The mean distance between the cervical phrenic nerve and the SAN in the posterior cervical triangle was 2.5 cm proximally, 4 cm at a midpoint, and 6 cm distally. The range for these measurements was 2 to 4 cm, 3.5 to 5 cm, and 4 to 8.5 cm, respectively. The mean excess length of SAN available after transposition to the more anteromedially placed phrenic nerve was 5 cm (range 4 to 6.5 cm). The mean diameter of these regional parts of the spinal accessory and phrenic nerves was 2 and 2.5 mm, respectively. No statistically significant difference was found for measurements between sides. To our knowledge, using the SAN for neurotization to the phrenic nerve for potential use in patients with spinal cord injury has not been previously explored. Following clinical trials, these data may provide a mechanism for self stimulation of the diaphragm and obviate phrenic nerve pacing in patients with high cervical quadriplegia. Our study found that such a maneuver is technically feasible in the cadaver.

Dynamic changes in phrenic motor output following high cervical hemisection in the decerebrate rat.

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Ghali, Michael George Zaki; Marchenko, Vitaliy

2015-09-01

Hemisection of the spinal cord at C2 eliminates ipsilateral descending drive to the phrenic nucleus and causes hemidiaphragmatic paralysis in rats. Phrenic nerve (PhN) or diaphragmatic activity ipsilateral to hemisection can occasionally be induced acutely following hemisection by respiratory stressors (i.e., hypercapnia, asphyxia, contralateral phrenicotomy) and becomes spontaneously active days-to-weeks later. These investigations, however, are potentially confounded by the use of anesthesia, which may suppress spontaneously-active crossed phrenic pathways. Experiments were performed on vecuronium-paralyzed, unanesthetized, decerebrate adult male rats and whole PhN activity recorded continuously before, during, and after high cervical hemisection at the C1 spinal level. Crossed phrenic activity recovered spontaneously over minutes-to-hours with maximal recovery of 11.8 ± 3.1% (m ± SE) in the PhN ipsilateral to hemisection. Additionally, there was a significant increase in PhN activity contralateral to hemisection of 221.0 ± 4 0.4% (m ± SE); since animals were artificially-ventilated, these changes likely represent an increase in central respiratory drive. These results underscore the state-dependence of crossed bulbophrenic projections and suggest that unanesthetized models may be more sensitive in detecting acute recovery of respiratory output following spinal cord injury (SCI). Additionally, our results may suggest an important role for a group of C1-C2 neurons exhibiting respiratory-related activity, spared by the higher level of hemisection. These units may function as relays of polysynaptic bulbophrenic pathways and/or provide excitatory drive to phrenic motoneurons. Our findings provide a new model for investigating acute respiratory recovery following cervical SCI, the high C1-hemisected unanesthetized decerebrate rat and suggest a centrally-mediated increase in central respiratory drive in response to high cervical SCI. Copyright © 2015. Published by

The terminal latency of the phrenic nerve correlates with respiratory symptoms in amyotrophic lateral sclerosis.

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Park, Jin-Sung; Park, Donghwi

2017-09-01

The aim of the study was to investigate the electrophysiological parameters in phrenic nerve conduction studies (NCS) that sensitively reflect latent respiratory insufficiency present in amyotrophic lateral sclerosis (ALS). Forty-nine patients with ALS were examined, and after exclusion, 21 patients with ALS and their phrenic NCS results were reviewed. The patients were divided into two groups according to their respiratory sub-score in the ALS functional rating scale - revised (Group A, sub-score 12vs. Group B, sub-score 11). We compared the parameters of phrenic NCS between the two groups. There were no significant differences in the clinical characteristics between the two groups. Using a multivariate model, we found that the terminal latency of the phrenic nerve was the only parameter that was associated with early symptoms of respiratory insufficiency (pphrenic nerve was 7.65ms (sensitivity 80%, specificity 68.2%). The significantly prolonged terminal latency of the phrenic nerve in our study may reflect a profound distal motor axonal dysfunction of the phrenic nerve in patients with ALS in the early stage of respiratory insufficiency that can be used as a sensitive electrophysiological marker reflecting respiratory symptoms in ALS. The terminal latency of the phrenic nerve is useful for early detection of respiratory insufficiency in patients with ALS. Copyright © 2017. Published by Elsevier B.V.

Prognosis of phrenic nerve injury following thoracic interventions: four new cases and a review.

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Ostrowska, Monika; de Carvalho, Mamede

2012-04-01

Phrenic nerve lesion is a known complication of thoracic surgical intervention, but it is rarely described following thymectomy and lung surgery. To review the literature on thoracic intervention and phrenic nerve lesion and to describe four new cases, in which regular neurophysiological studies were performed. We reviewed the literature concerning phrenic nerve lesion after cardiac, lung and thymus surgical interventions. We described four cases of phrenic nerve lesion, three associated with thymectomy and one in lung surgery. The review shows that cryogenic or thermal injuries during cardiac surgeries are associated with good prognosis. The information on the outcome of phrenic nerve lesion in thymectomy or lung surgery is insufficient. Our cases and this review suggest that phrenic lesion in the last two interventions are associated with a poor recovery. Our data suggests that the prognosis of phrenic nerve lesion following thoracic intervention depends on the nature of the damage. Probably, in thymectomy and lung surgery, nerve stretch or laceration are involved, consequently the outcome is poorer in comparison with cardiac surgery, where cold lesion is more frequent. Neurophysiological tests give a direct, quantified and reliable assessment of nerve regeneration. Copyright © 2011 Elsevier B.V. All rights reserved.

The crossed phrenic phenomenon

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Ghali, Michael George Zaki

2017-01-01

The cervical spine is the most common site of traumatic vertebral column injuries. Respiratory insufficiency constitutes a significant proportion of the morbidity burden and is the most common cause of mortality in these patients. In seeking to enhance our capacity to treat specifically the respiratory dysfunction following spinal cord injury, investigators have studied the “crossed phrenic phenomenon”, wherein contraction of a hemidiaphragm paralyzed by a complete hemisection of the ipsilateral cervical spinal cord above the phrenic nucleus can be induced by respiratory stressors and recovers spontaneously over time. Strengthening of latent contralateral projections to the phrenic nucleus and sprouting of new descending axons have been proposed as mechanisms contributing to the observed recovery. We have recently demonstrated recovery of spontaneous crossed phrenic activity occurring over minutes to hours in C1-hemisected unanesthetized decerebrate rats. The specific neurochemical and molecular pathways underlying crossed phrenic activity following injury require further clarification. A thorough understanding of these is necessary in order to develop targeted therapies for respiratory neurorehabilitation following spinal trauma. Animal studies provide preliminary evidence for the utility of neuropharmacological manipulation of serotonergic and adenosinergic pathways, nerve grafts, olfactory ensheathing cells, intraspinal microstimulation and a possible role for dorsal rhizotomy in recovering phrenic activity following spinal cord injury PMID:28761411

The crossed phrenic phenomenon

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Michael George Zaki Ghali

2017-01-01

Full Text Available The cervical spine is the most common site of traumatic vertebral column injuries. Respiratory insufficiency constitutes a significant proportion of the morbidity burden and is the most common cause of mortality in these patients. In seeking to enhance our capacity to treat specifically the respiratory dysfunction following spinal cord injury, investigators have studied the “crossed phrenic phenomenon”, wherein contraction of a hemidiaphragm paralyzed by a complete hemisection of the ipsilateral cervical spinal cord above the phrenic nucleus can be induced by respiratory stressors and recovers spontaneously over time. Strengthening of latent contralateral projections to the phrenic nucleus and sprouting of new descending axons have been proposed as mechanisms contributing to the observed recovery. We have recently demonstrated recovery of spontaneous crossed phrenic activity occurring over minutes to hours in C1-hemisected unanesthetized decerebrate rats. The specific neurochemical and molecular pathways underlying crossed phrenic activity following injury require further clarification. A thorough understanding of these is necessary in order to develop targeted therapies for respiratory neurorehabilitation following spinal trauma. Animal studies provide preliminary evidence for the utility of neuropharmacological manipulation of serotonergic and adenosinergic pathways, nerve grafts, olfactory ensheathing cells, intraspinal microstimulation and a possible role for dorsal rhizotomy in recovering phrenic activity following spinal cord injury

The crossed phrenic phenomenon.

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Ghali, Michael George Zaki

2017-06-01

The cervical spine is the most common site of traumatic vertebral column injuries. Respiratory insufficiency constitutes a significant proportion of the morbidity burden and is the most common cause of mortality in these patients. In seeking to enhance our capacity to treat specifically the respiratory dysfunction following spinal cord injury, investigators have studied the "crossed phrenic phenomenon", wherein contraction of a hemidiaphragm paralyzed by a complete hemisection of the ipsilateral cervical spinal cord above the phrenic nucleus can be induced by respiratory stressors and recovers spontaneously over time. Strengthening of latent contralateral projections to the phrenic nucleus and sprouting of new descending axons have been proposed as mechanisms contributing to the observed recovery. We have recently demonstrated recovery of spontaneous crossed phrenic activity occurring over minutes to hours in C 1 -hemisected unanesthetized decerebrate rats. The specific neurochemical and molecular pathways underlying crossed phrenic activity following injury require further clarification. A thorough understanding of these is necessary in order to develop targeted therapies for respiratory neurorehabilitation following spinal trauma. Animal studies provide preliminary evidence for the utility of neuropharmacological manipulation of serotonergic and adenosinergic pathways, nerve grafts, olfactory ensheathing cells, intraspinal microstimulation and a possible role for dorsal rhizotomy in recovering phrenic activity following spinal cord injury.

Thoracoscopic phrenic nerve patch insulation to avoid phrenic nerve stimulation with cardiac resynchronization therapy

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Masatsugu Nozoe, MD, PhD

2014-04-01

Full Text Available A 76-year-old female was implanted with a cardiac resynchronization therapy (CRT device, with the left ventricular lead implanted through a transvenous approach. One day after implantation, diaphragmatic stimulation was observed when the patient was in the seated position, which could not be resolved by device reprogramming. We performed thoracoscopic phrenic nerve insulation using a Gore-Tex patch. The left phrenic nerve was carefully detached from the pericardial adipose tissue, and a Gore-Tex patch was inserted between the phrenic nerve and pericardium using a thoracoscopic technique. This approach represents a potential option for the management of uncontrollable phrenic nerve stimulation during CRT.

Comparative study of phrenic nerve transfers with and without nerve graft for elbow flexion after global brachial plexus injury.

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Liu, Yuzhou; Lao, Jie; Gao, Kaiming; Gu, Yudong; Zhao, Xin

2014-01-01

Nerve transfer is a valuable surgical technique in peripheral nerve reconstruction, especially in brachial plexus injuries. Phrenic nerve transfer for elbow flexion was proved to be one of the optimal procedures in the treatment of brachial plexus injuries in the study of Gu et al. The aim of this study was to compare phrenic nerve transfers with and without nerve graft for elbow flexion after brachial plexus injury. A retrospective review of 33 patients treated with phrenic nerve transfer for elbow flexion in posttraumatic global root avulsion brachial plexus injury was carried out. All the 33 patients were confirmed to have global root avulsion brachial plexus injury by preoperative and intraoperative electromyography (EMG), physical examination and especially by intraoperative exploration. There were two types of phrenic nerve transfers: type1 - the phrenic nerve to anterolateral bundle of anterior division of upper trunk (14 patients); type 2 - the phrenic nerve via nerve graft to anterolateral bundle of musculocutaneous nerve (19 patients). Motor function and EMG evaluation were performed at least 3 years after surgery. The efficiency of motor function in type 1 was 86%, while it was 84% in type 2. The two groups were not statistically different in terms of Medical Research Council (MRC) grade (p=1.000) and EMG results (p=1.000). There were seven patients with more than 4 month's delay of surgery, among whom only three patients regained biceps power to M3 strength or above (43%). A total of 26 patients had reconstruction done within 4 months, among whom 25 patients recovered to M3 strength or above (96%). There was a statistically significant difference of motor function between the delay of surgery within 4 months and more than 4 months (p=0.008). Phrenic nerve transfers with and without nerve graft for elbow flexion after brachial plexus injury had no significant difference for biceps reinnervation according to MRC grading and EMG. A delay of the surgery

High-frequency epidural stimulation across the respiratory cycle evokes phrenic short-term potentiation after incomplete cervical spinal cord injury.

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Gonzalez-Rothi, Elisa J; Streeter, Kristi A; Hanna, Marie H; Stamas, Anna C; Reier, Paul J; Baekey, David M; Fuller, David D

2017-10-01

C2 spinal hemilesion (C2Hx) paralyzes the ipsilateral diaphragm, but recovery is possible through activation of "crossed spinal" synaptic inputs to ipsilateral phrenic motoneurons. We tested the hypothesis that high-frequency epidural stimulation (HF-ES) would potentiate ipsilateral phrenic output after subacute and chronic C2Hx. HF-ES (300 Hz) was applied to the ventrolateral C4 or T2 spinal cord ipsilateral to C2Hx in anesthetized and mechanically ventilated adult rats. Stimulus duration was 60 s, and currents ranged from 100 to 1,000 µA. Bilateral phrenic nerve activity and ipsilateral hypoglossal (XII) nerve activity were recorded before and after HF-ES. Higher T2 stimulus currents potentiated ipsilateral phasic inspiratory activity at both 2 and 12 wk post-C2Hx, whereas higher stimulus currents delivered at C4 potentiated ipsilateral phasic phrenic activity only at 12 wk ( P = 0.028). Meanwhile, tonic output in the ipsilateral phrenic nerve reached 500% of baseline values at the high currents with no difference between 2 and 12 wk. HF-ES did not trigger inspiratory burst-frequency changes. Similar responses occurred following T2 HF-ES. Increases in contralateral phrenic and XII nerve output were induced by C4 and T2 HF-ES at higher currents, but the relative magnitude of these changes was small compared with the ipsilateral phrenic response. We conclude that following incomplete cervical spinal cord injury, HF-ES of the ventrolateral midcervical or thoracic spinal cord can potentiate efferent phrenic motor output with little impact on inspiratory burst frequency. However, the substantial increases in tonic output indicate that the uninterrupted 60-s stimulation paradigm used is unlikely to be useful for respiratory muscle activation after spinal injury. NEW & NOTEWORTHY Previous studies reported that high-frequency epidural stimulation (HF-ES) activates the diaphragm following acute spinal transection. This study examined HF-ES and phrenic motor output

Respiratory function after selective respiratory motor neuron death from intrapleural CTB–saporin injections

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Nichols, Nicole L.; Vinit, Stéphane; Bauernschmidt, Lorene; Mitchell, Gordon S.

2015-01-01

Amyotrophic lateral sclerosis (ALS) causes progressive motor neuron degeneration, paralysis and death by ventilatory failure. In rodent ALS models: 1) breathing capacity is preserved until late in disease progression despite major respiratory motor neuron death, suggesting unknown forms of compensatory respiratory plasticity; and 2) spinal microglia become activated in association with motor neuron cell death. Here, we report a novel experimental model to study the impact of respiratory motor neuron death on compensatory responses without many complications attendant to spontaneous motor neuron disease. In specific, we used intrapleural injections of cholera toxin B fragment conjugated to saporin (CTB–SAP) to selectively kill motor neurons with access to the pleural space. Motor neuron survival, CD11b labeling (microglia), ventilatory capacity and phrenic motor output were assessed in rats 3–28 days after intrapleural injections of: 1) CTB–SAP (25 and 50 μg), or 2) unconjugated CTB and SAP (i.e. control; (CTB + SAP). CTB–SAP elicited dose-dependent phrenic and intercostal motor neuron death; 7 days post-25 μg CTB–SAP, motor neuron survival approximated that in end-stage ALS rats (phrenic: 36 ± 7%; intercostal: 56 ± 10% of controls; n = 9; p phrenic motor nucleus, indicating microglial activation; 2) decreased breathing during maximal chemoreceptor stimulation; and 3) diminished phrenic motor output in anesthetized rats (7 days post-25 μg, CTB–SAP: 0.3 ± 0.07 V; CTB + SAP: 1.5 ± 0.3; n = 9; p < 0.05). Intrapleural CTB–SAP represents a novel, inducible model of respiratory motor neuron death and provides an opportunity to study compensation for respiratory motor neuron loss. PMID:25476493

Hypoxia triggers short term potentiation of phrenic motoneuron discharge after chronic cervical spinal cord injury

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Lee, Kun-Ze; Sandhu, Milapjit S.; Dougherty, Brendan J.; Reier, Paul J.; Fuller, David D.

2014-01-01

Repeated exposure to hypoxia can induce spinal neuroplasticity as well as respiratory and somatic motor recovery after spinal cord injury (SCI). The purpose of the present study was to define the capacity for a single bout of hypoxia to trigger short-term plasticity in phrenic output after cervical SCI, and to determine the phrenic motoneuron (PhrMN) bursting and recruitment patterns underlying the response. Hypoxia-induced short term potentiation (STP) of phrenic motor output was quantified in anesthetized rats 11 wks following lateral spinal hemisection at C2 (C2Hx). A 3-min hypoxic episode (12–14% O2) always triggered STP of inspiratory burst amplitude, the magnitude of which was greater in phrenic bursting ipsilateral vs. contralateral to C2Hx. We next determined if STP could be evoked in recruited (silent) PhrMNs ipsilateral to C2Hx. Individual PhrMN action potentials were recorded during and following hypoxia using a “single fiber” approach. STP of bursting activity did not occur in cells initiating bursting at inspiratory onset, but was robust in recruited PhrMNs as well as previously active cells initiating bursting later in the inspiratory effort. We conclude that following chronic C2Hx, a single bout of hypoxia triggers recruitment of PhrMNs in the ipsilateral spinal cord with bursting that persists beyond the hypoxic exposure. The results provide further support for the use of short bouts of hypoxia as a neurorehabilitative training modality following SCI. PMID:25448009

Comparative study of phrenic and intercostal nerve transfers for elbow flexion after global brachial plexus injury.

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Liu, Yuzhou; Lao, Jie; Zhao, Xin

2015-04-01

Global brachial plexus injuries (BPIs) are devastating events frequently resulting in severe functional impairment. The widely used nerve transfer sources for elbow flexion in patients with global BPIs include intercostal and phrenic nerves. The aim of this study was to compare phrenic and intercostal nerve transfers for elbow flexion after global BPI. A retrospective review of 33 patients treated with phrenic and intercostal nerve transfer for elbow flexion in posttraumatic global root avulsion BPI was carried out. In the phrenic nerve transfer group, the phrenic nerve was transferred to the anterolateral bundle of the anterior division of the upper trunk (23 patients); in the intercostal nerve transfer group, three intercostal nerves were coapted to the anterolateral bundles of the musculocutaneous nerve. The British Medical Research Council (MRC) grading system, angle of elbow flexion, and electromyography (EMG) were used to evaluate the recovery of elbow flexion at least 3 years postoperatively. The efficiency of motor function in the phrenic nerve transfer group was 83%, while it was 70% in the intercostal nerve transfer group. The two groups were not statistically different in terms of the MRC grade (p=0.646) and EMG results (p=0.646). The outstanding rates of angle of elbow flexion were 48% and 40% in the phrenic and intercostal nerve transfer groups, respectively. There was no significant difference of outstanding rates in the angle of elbow flexion between the two groups. Phrenic nerve transfer had a higher proportion of good prognosis for elbow flexion than intercostal nerve transfer, but the effective and outstanding rate had no significant difference for biceps reinnervation between the two groups according to MRC grading, angle of elbow flexion, and EMG. Copyright © 2014 Elsevier Ltd. All rights reserved.

Long lasting structural changes in primary motor cortex after motor skill learning: a behavioural and stereological study

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PAOLA MORALES

2008-12-01

Full Text Available Many motor skills, once acquired, are stored over a long time period, probably sustained by permanent neuronal changes. Thus, in this paper we have investigated with quantitative stereology the generation and persistence of neuronal density changes in primary motor cortex (MI following motor skill learning (skilled reaching task. Rats were trained a lateralised reaching task during an "early" (22-31 days oíd or "late" (362-371 days oíd postnatal period. The trained and corresponding control rats were sacrificed at day 372, immediately after the behavioural testing. The "early" trained group preserved the learned skilled reaching task when tested at day 372, without requiring any additional training. The "late" trained group showed a similar capacity to that of the "early" trained group for learning the skilled reaching task. All trained animáis ("early" and "late" trained groups showed a significant Ínter hemispheric decrease of neuronal density in the corresponding motor forelimb representation área of MI (cortical layers II-III

Left phrenic nerve anatomy relative to the coronary venous system: Implications for phrenic nerve stimulation during cardiac resynchronization therapy.

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Spencer, Julianne H; Goff, Ryan P; Iaizzo, Paul A

2015-07-01

The objective of this study was to quantitatively characterize anatomy of the human phrenic nerve in relation to the coronary venous system, to reduce undesired phrenic nerve stimulation during left-sided lead implantations. We obtained CT scans while injecting contrast into coronary veins of 15 perfusion-fixed human heart-lung blocs. A radiopaque wire was glued to the phrenic nerve under CT, then we created three-dimensional models of anatomy and measured anatomical parameters. The left phrenic nerve typically coursed over the basal region of the anterior interventricular vein, mid region of left marginal veins, and apical region of inferior and middle cardiac veins. There was large variation associated with the average angle between nerve and veins. Average angle across all coronary sinus tributaries was fairly consistent (101.3°-111.1°). The phrenic nerve coursed closest to the middle cardiac vein and left marginal veins. The phrenic nerve overlapped a left marginal vein in >50% of specimens. © 2015 Wiley Periodicals, Inc.

Prospective Evaluation of Electromyography-Guided Phrenic Nerve Monitoring During Superior Vena Cava Isolation to Anticipate Phrenic Nerve Injury.

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Miyazaki, Shinsuke; Ichihara, Noboru; Nakamura, Hiroaki; Taniguchi, Hiroshi; Hachiya, Hitoshi; Araki, Makoto; Takagi, Takamitsu; Iwasawa, Jin; Kuroi, Akio; Hirao, Kenzo; Iesaka, Yoshito

2016-04-01

Right phrenic nerve injury (PNI) is a major concern during superior vena cava (SVC) isolation due to the anatomical close proximity. The functional and histological severity of PNI parallels the degree of the reduction in the compound motor action potential (CMAP) amplitude. This study aimed to evaluate the feasibility of monitoring CMAPs during SVC isolation to anticipate PNI during atrial fibrillation (AF) ablation. Thirty-nine paroxysmal AF patients were prospectively enrolled. Radiofrequency energy was delivered point-by-point for 30 seconds with 20 W until eliminating all SVC potentials after the pulmonary vein isolation. Right diaphragmatic CMAPs were obtained from modified surface electrodes by pacing from the right subclavian vein. Radiofrequency applications were applied without fluoroscopy under CMAP monitoring at sites with phrenic nerve capture by high output pacing. Electrical SVC isolation was successfully achieved with a mean of 9.4 ± 3.3 applications in all patients. In 3 (7.5%) patients, the SVC was isolated without radiofrequency delivery at phrenic nerve capture sites. Among a total of 346 applications in the remaining 36 patients, 71 (20.5%) were delivered while monitoring CMAPs. In 1 (1.4%) application, the RF application was interrupted due to a decrease in the CMAP amplitude. However, no PNI was detected on fluoroscopy, and the decreased amplitude recovered spontaneously. The remaining 70 (98.6%) applications exhibited no significant changes in the CMAP amplitude throughout the applications (from 1.01 ± 0.47 to 0.98 ± 0.45 mV, P = 0.383). Stable right diaphragmatic CMAPs could be obtained, and monitoring CMAPs might be useful for anticipating right PNI during SVC isolation. © 2016 Wiley Periodicals, Inc.

21 CFR 882.5830 - Implanted diaphragmatic/phrenic nerve stimulator.

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2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted diaphragmatic/phrenic nerve stimulator... Implanted diaphragmatic/phrenic nerve stimulator. (a) Identification. An implanted diaphragmatic/phrenic nerve stimulator is a device that provides electrical stimulation of a patient's phrenic nerve to...

Inflammatory nodule mimicking a phrenic neoplasm.

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Vannucci, Jacopo; Scarnecchia, Elisa; Del Sordo, Rachele; Cagini, Lucio; Puma, Francesco

2016-05-01

Isolated phrenic nerve nodule is usually a primitive tumour. Surgery is diagnostic and therapeutic at the same time. We report the case of a completely serum-negative Caucasian male with a right diaphragmatic relaxation associated to an isolated small nodule of the phrenic nerve. The patient was referred to our unit complaining shortness of breath and progressive fatigue. A standard chest X-ray showed right diaphragmatic palsy; chest scanning revealed a nodular lesion belonging to the right phrenic nerve. Positron emission tomography was negative for glucose uptake. The preoperative diagnosis of primitive neurogenic tumour was thus supposed, and the patient treated by the lesion's surgical resection along with diaphragmatic plication. Histopathological examination revealed an idiopathic inflammatory nodule of the phrenic nerve. Such condition has not previously been reported in the literature among the possible aetiology of a diaphragmatic relaxation. © 2014 John Wiley & Sons Ltd.

Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation.

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Seven, Yasin B; Mantilla, Carlos B; Sieck, Gary C

2014-12-01

Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P motor units were recruited ∼30 ms earlier (P motor unit onset discharge frequencies were significantly higher (P Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. Copyright © 2014 the American Physiological Society.

Thoracoscopic phrenic nerve patch insulation to avoid phrenic nerve stimulation with cardiac resynchronization therapy

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Nozoe, Masatsugu; Tanaka, Yasuaki; Koyama, Junjiroh; Oshitomi, Takashi; Honda, Toshihiro; Yoshioka, Masakazu; Iwatani, Kazunori; Hirayama, Touitsu; Nakao, Koichi

2014-01-01

A 76-year-old female was implanted with a cardiac resynchronization therapy (CRT) device, with the left ventricular lead implanted through a transvenous approach. One day after implantation, diaphragmatic stimulation was observed when the patient was in the seated position, which could not be resolved by device reprogramming. We performed thoracoscopic phrenic nerve insulation using a Gore-Tex patch. The left phrenic nerve was carefully detached from the pericardial adipose tissue, and a Gore...

Respiratory function after selective respiratory motor neuron death from intrapleural CTB-saporin injections.

Science.gov (United States)

Nichols, Nicole L; Vinit, Stéphane; Bauernschmidt, Lorene; Mitchell, Gordon S

2015-05-01

Amyotrophic lateral sclerosis (ALS) causes progressive motor neuron degeneration, paralysis and death by ventilatory failure. In rodent ALS models: 1) breathing capacity is preserved until late in disease progression despite major respiratory motor neuron death, suggesting unknown forms of compensatory respiratory plasticity; and 2) spinal microglia become activated in association with motor neuron cell death. Here, we report a novel experimental model to study the impact of respiratory motor neuron death on compensatory responses without many complications attendant to spontaneous motor neuron disease. In specific, we used intrapleural injections of cholera toxin B fragment conjugated to saporin (CTB-SAP) to selectively kill motor neurons with access to the pleural space. Motor neuron survival, CD11b labeling (microglia), ventilatory capacity and phrenic motor output were assessed in rats 3-28days after intrapleural injections of: 1) CTB-SAP (25 and 50μg), or 2) unconjugated CTB and SAP (i.e. control; (CTB+SAP). CTB-SAP elicited dose-dependent phrenic and intercostal motor neuron death; 7days post-25μg CTB-SAP, motor neuron survival approximated that in end-stage ALS rats (phrenic: 36±7%; intercostal: 56±10% of controls; n=9; pneuron death and provides an opportunity to study compensation for respiratory motor neuron loss. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of phrenic nerve and diaphragm function with peripheral nerve stimulation and M-mode ultrasonography in potential pediatric phrenic nerve or diaphragm pacing candidates.

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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.

Internal Thoracic Artery Encircled by an Unusual Phrenic Nerve Loop

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Robert Fu-Chean Chen

2007-12-01

Full Text Available We report an anatomic variation of the phrenic nerve. During a routine gross anatomical dissection course at our medical university, we found an unusual loop of the left phrenic nerve around the internal thoracic artery, about 1 cm from the take-off of the left subclavian artery. The phrenic nerve is close to the internal thoracic artery and is easily injured when dissecting the internal thoracic artery for coronary artery bypass conduit. Therefore, we suggest that the anatomic relationship of the phrenic nerve and internal thoracic artery is important in preventing incidental injury of the phrenic nerve.

Phrenic nerve reconstruction in complete video-assisted thoracic surgery.

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Kawashima, Shun; Kohno, Tadasu; Fujimori, Sakashi; Yokomakura, Naoya; Ikeda, Takeshi; Harano, Takashi; Suzuki, Souichiro; Iida, Takahiro; Sakai, Emi

2015-01-01

Primary or metastatic lung cancer or mediastinal tumours may at times involve the phrenic nerve and pericardium. To remove the pathology en bloc, the phrenic nerve must be resected. This results in phrenic nerve paralysis, which in turn reduces pulmonary function and quality of life. As a curative measure of this paralysis and thus a preventive measure against decreased pulmonary function and quality of life, we have performed immediate phrenic nerve reconstruction under complete video-assisted thoracic surgery, and with minimal additional stress to the patient. This study sought to ascertain the utility of this procedure from an evaluation of the cases experienced to date. We performed 6 cases of complete video-assisted thoracic surgery phrenic nerve reconstruction from October 2009 to December 2013 in patients who had undergone phrenic nerve resection or separation to remove tumours en bloc. In all cases, it was difficult to separate the phrenic nerve from the tumour. Reconstruction involved direct anastomosis in 3 cases and intercostal nerve interposition anastomosis in the remaining 3 cases. In the 6 patients (3 men, 3 women; mean age 50.8 years), we performed two right-sided and four left-sided procedures. The mean anastomosis time was 5.3 min for direct anastomosis and 35.3 min for intercostal nerve interposition anastomosis. Postoperative phrenic nerve function was measured on chest X-ray during inspiration and expiration. Direct anastomosis was effective in 2 of the 3 patients, and intercostal nerve interposition anastomosis was effective in all 3 patients. Diaphragm function was confirmed on X-ray to be improved in these 5 patients. Complete video-assisted thoracic surgery phrenic nerve reconstruction was effective for direct anastomosis as well as for intercostal nerve interposition anastomosis in a small sample of selected patients. The procedure shows promise for phrenic nerve reconstruction and further data should be accumulated over time. © The

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

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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.

Clinical experience with a novel electromyographic approach to preventing phrenic nerve injury during cryoballoon ablation in atrial fibrillation.

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Mondésert, Blandine; Andrade, Jason G; Khairy, Paul; Guerra, Peter G; Dyrda, Katia; Macle, Laurent; Rivard, Léna; Thibault, Bernard; Talajic, Mario; Roy, Denis; Dubuc, Marc; Shohoudi, Azadeh

2014-08-01

Phrenic nerve palsy remains the most frequent complication associated with cryoballoon-based pulmonary vein (PV) isolation. We sought to characterize our experience using a novel monitoring technique for the prevention of phrenic nerve palsy. Two hundred consecutive cryoballoon-based PV isolation procedures between October 2010 and October 2013 were studied. In addition to standard abdominal palpation during right phrenic nerve pacing from the superior vena cava, all patients underwent diaphragmatic electromyographic monitoring using surface electrodes. Cryoablation was terminated on any perceived reduction in diaphragmatic motion or a 30% decrease in the compound motor action potential (CMAP). During right-sided ablation, a ≥30% reduction in CMAP amplitude occurred in 49 patients (24.5%). Diaphragmatic motion decreased in 30 of 49 patients and was preceded by a 30% reduction in CMAP amplitude in all. In 82% of cases, this reduction in CMAP amplitude occurred during right superior PV isolation. The baseline CMAP amplitude was 946.5±609.2 mV and decreased by 13.8±13.8% at the end of application. This decrease was more marked in the 33 PVs with a reduction in diaphragmatic motion than in those without (40.9±15.3% versus 11.3±10.5%; Pphrenic nerve palsy persisted beyond the end of the procedure, with all cases recovering within 6 months. Despite the shortened application all veins were isolated. At repeat procedure the right-sided PVs reconnected less frequently than the left-sided PVs in those with phrenic nerve palsy. Electromyographic phrenic nerve monitoring using the surface CMAP is reliable, easy to perform, and offers an early warning to impending phrenic nerve injury. © 2014 American Heart Association, Inc.

The subdiaphragmatic part of the phrenic nerve - morphometry and connections to autonomic ganglia.

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Loukas, Marios; Du Plessis, Maira; Louis, Robert G; Tubbs, R Shane; Wartmann, Christopher T; Apaydin, Nihal

2016-01-01

Few anatomical textbooks offer much information concerning the anatomy and distribution of the phrenic nerve inferior to the diaphragm. The aim of this study was to identify the subdiaphragmatic distribution of the phrenic nerve, the presence of phrenic ganglia, and possible connections to the celiac plexus. One hundred and thirty formalin-fixed adult cadavers were studied. The right phrenic nerve was found inferior to the diaphragm in 98% with 49.1% displaying a right phrenic ganglion. In 22.8% there was an additional smaller ganglion (right accessory phrenic ganglion). The remaining 50.9% had no grossly identifiable right phrenic ganglion. Most (65.5% of specimens) exhibited plexiform communications with the celiac ganglion, aorticorenal ganglion, and suprarenal gland. The left phrenic nerve inferior to the diaphragm was observed in 60% of specimens with 19% containing a left phrenic ganglion. No accessory left phrenic ganglia were observed. The left phrenic ganglion exhibited plexiform communications to several ganglia in 71.4% of specimens. Histologically, the right phrenic and left phrenic ganglia contained large soma concentrated in their peripheries. Both phrenic nerves and ganglia were closely related to the diaphragmatic crura. Surgically, sutures to approximate the crura for repair of hiatal hernias must be placed above the ganglia in order to avoid iatrogenic injuries to the autonomic supply to the diaphragm and abdomen. These findings could also provide a better understanding of the anatomy and distribution of the fibers of that autonomic supply. © 2015 Wiley Periodicals, Inc.

Phrenic Nerve Stimulation: Technology and Clinical Applications.

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Abdunnur, Shane V; Kim, Daniel H

2015-01-01

Phrenic nerve stimulation is a technique used to reanimate the diaphragm of patients with central nervous system etiologies of respiratory insufficiency. Current clinical indications include congenital central hypoventilation syndrome, spinal cord injury above C4, brain stem injury, and idiopathic severe sleep apnea. Presurgical evaluation ensures proper patient selection by validating the intact circuit from the phrenic nerve through alveolar oxygenation. The procedure involves placing leads around the phrenic nerves bilaterally and attaching these leads to radio receivers in a subcutaneous pocket. The rate and amplitude of the current is adjusted via an external radio transmitter. After implantation, each patient progresses through a conditioning phase that strengthens the diaphragm and progressively provides independence from the mechanical ventilator. Studies indicate that patients and families experience an improved quality of life and are satisfied with the results. Phrenic nerve stimulation provides a safe and effective means for reanimating the diaphragm for certain patients with respiratory insufficiency, providing independence from mechanical ventilation. © 2016 S. Karger AG, Basel.

Histological identification of phrenic afferent projections to the spinal cord.

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Nair, Jayakrishnan; Bezdudnaya, Tatiana; Zholudeva, Lyandysha V; Detloff, Megan R; Reier, Paul J; Lane, Michael A; Fuller, David D

2017-02-01

Limited data are available regarding the spinal projections of afferent fibers in the phrenic nerve. We describe a method that robustly labels phrenic afferent spinal projections in adult rats. The proximal end of the cut phrenic nerve was secured in a microtube filled with a transganglionic tracer (cholera toxin β-subunit, CT-β, or Cascade Blue) and tissues harvested 96-h later. Robust CT-β labeling occurred in C3-C5 dorsal root ganglia cell bodies and phrenic afferent projections were identified in the mid-cervical dorsal horn (laminae I-III), intermediate grey matter (laminae IV, VII) and near the central canal (laminae X). Afferent fiber labeling was reduced or absent when CT-β was delivered to the intrapleural space or directly to the hemidiaphragm. Soaking the phrenic nerve with Cascade Blue also produced robust labeling of mid-cervical dorsal root ganglia cells bodies, and primary afferent fibers were observed in spinal grey matter and dorsal white matter. Our results show that the 'nerve soak' method effectively labels both phrenic motoneurons and phrenic afferent projections, and show that primary afferents project throughout the ipsilateral mid-cervical gray matter. Copyright © 2016. Published by Elsevier B.V.

Long-Lasting Cortical Reorganization as the Result of Motor Imagery of Throwing a Ball in a Virtual Tennis Court

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Cebolla, Ana M.; Petieau, Mathieu; Cevallos, Carlos; Leroy, Axelle; Dan, Bernard; Cheron, Guy

2015-01-01

In order to characterize the neural signature of a motor imagery (MI) task, the present study investigates for the first time the oscillation characteristics including both of the time-frequency measurements, event related spectral perturbation and intertrial coherence (ITC) underlying the variations in the temporal measurements (event related potentials, ERP) directly related to a MI task. We hypothesize that significant variations in both of the time-frequency measurements underlie the specific changes in the ERP directly related to MI. For the MI task, we chose a simple everyday task (throwing a tennis ball), that does not require any particular motor expertise, set within the controlled virtual reality scenario of a tennis court. When compared to the rest condition a consistent, long-lasting negative fronto-central ERP wave was accompanied by significant changes in both time frequency measurements suggesting long-lasting cortical activity reorganization. The ERP wave was characterized by two peaks at about 300 ms (N300) and 1000 ms (N1000). The N300 component was centrally localized on the scalp and was accompanied by significant phase consistency in the delta brain rhythms in the contralateral central scalp areas. The N1000 component spread wider centrally and was accompanied by a significant power decrease (or event related desynchronization) in low beta brain rhythms localized in fronto-precentral and parieto-occipital scalp areas and also by a significant power increase (or event related synchronization) in theta brain rhythms spreading fronto-centrally. During the transition from N300 to N1000, a contralateral alpha (mu) as well as post-central and parieto-theta rhythms occurred. The visual representation of movement formed in the minds of participants might underlie a top-down process from the fronto-central areas which is reflected by the amplitude changes observed in the fronto-central ERPs and by the significant phase synchrony in contralateral fronto

Phrenic neuropathy in chronic renal failure.

OpenAIRE

Zifko, U.; Auinger, M.; Albrecht, G.; Kästenbauer, T.; Lahrmann, H.; Grisold, W.; Wanke, T.

1995-01-01

BACKGROUND--Peripheral neuropathy and alterations in diaphragmatic muscle function are frequently caused by uraemia. Phrenic nerve function in patients with end stage renal failure, however, has not been examined to date. METHODS--An electrophysiological study of the phrenic nerve was performed to determine its possible involvement in 32 nondiabetic patients with end stage renal disease undergoing chronic haemodialysis. RESULTS--Seventeen patients had electrophysiological signs of peripheral ...

Phrenic nerve conduction studies: normative data and technical aspects

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Analucia Abreu Maranhão

Full Text Available ABSTRACT Objective: The aim of the present study was to define normative data of phrenic nerve conduction parameters of a healthy population. Methods: Phrenic nerve conduction studies were performed in 27 healthy volunteers. Results: The normative limits for expiratory phrenic nerve compound muscle action potential were: amplitude (0.47 mv - 0.83 mv, latency (5.74 ms - 7.10 ms, area (6.20 ms/mv - 7.20 ms/mv and duration (18.30 ms - 20.96 ms. Inspiratory normative limits were: amplitude (0.67 mv - 1.11 mv, latency (5.90 ms - 6.34 ms, area (5.62 ms/mv - 6.72 ms/mv and duration (13.77 ms - 15.37 ms. Conclusion: The best point of phrenic nerve stimulus in the neck varies among individuals between the medial and lateral border of the clavicular head of the sternocleidomastoid muscle and stimulation of both sites, then choosing the best phrenic nerve response, seems to be the appropriate procedure.

Phrenic nerve conduction studies: normative data and technical aspects.

Science.gov (United States)

Maranhão, Analucia Abreu; Carvalho, Sonia Regina da Silva; Caetano, Marcelo Ribeiro; Alamy, Alexandre Hofke; Peixoto, Eduardo Mesquita; Filgueiras, Pedro Del Esporte Peçanha

2017-12-01

The aim of the present study was to define normative data of phrenic nerve conduction parameters of a healthy population. Phrenic nerve conduction studies were performed in 27 healthy volunteers. The normative limits for expiratory phrenic nerve compound muscle action potential were: amplitude (0.47 mv - 0.83 mv), latency (5.74 ms - 7.10 ms), area (6.20 ms/mv - 7.20 ms/mv) and duration (18.30 ms - 20.96 ms). Inspiratory normative limits were: amplitude (0.67 mv - 1.11 mv), latency (5.90 ms - 6.34 ms), area (5.62 ms/mv - 6.72 ms/mv) and duration (13.77 ms - 15.37 ms). The best point of phrenic nerve stimulus in the neck varies among individuals between the medial and lateral border of the clavicular head of the sternocleidomastoid muscle and stimulation of both sites, then choosing the best phrenic nerve response, seems to be the appropriate procedure.

Mammalian target of rapamycin is required for phrenic long-term facilitation following severe but not moderate acute intermittent hypoxia.

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Dougherty, Brendan J; Fields, Daryl P; Mitchell, Gordon S

2015-09-01

Phrenic long-term facilitation (pLTF) is a persistent increase in phrenic nerve activity after acute intermittent hypoxia (AIH). Distinct cell-signaling cascades give rise to pLTF depending on the severity of hypoxemia within hypoxic episodes. Moderate AIH (mAIH; three 5-min episodes, PaO2 ∼35-55 mmHG) elicits pLTF by a serotonin (5-HT)-dependent mechanism that requires new synthesis of brain-derived neurotrophic factor (BDNF), activation of its high-affinity receptor (TrkB), and ERK MAPK signaling. In contrast, severe AIH (sAIH; three 5-min episodes, PaO2 ∼25-30 mmHG) elicits pLTF by an adenosine-dependent mechanism that requires new TrkB synthesis and Akt signaling. Although both mechanisms require spinal protein synthesis, the newly synthesized proteins are distinct, as are the neurochemicals inducing plasticity (serotonin vs. adenosine). In many forms of neuroplasticity, new protein synthesis requires translational regulation via mammalian target of rapamycin (mTOR) signaling. Since Akt regulates mTOR activity, we hypothesized that mTOR activity is necessary for sAIH- but not mAIH-induced pLTF. Phrenic nerve activity in anesthetized, paralyzed, and ventilated rats was recorded before, during, and 60 min after mAIH or sAIH. Rats were pretreated with intrathecal injections of 20% DMSO (vehicle controls) or rapamycin (0.1 mM, 12 μl), a selective mTOR complex 1 inhibitor. Consistent with our hypothesis, rapamycin blocked sAIH- but not mAIH-induced pLTF. Thus spinal mTOR activity is required for adenosine-dependent (sAIH) but not serotonin-dependent (mAIH) pLTF, suggesting that distinct mechanisms regulate new protein synthesis in these forms of spinal neuroplasticity. Copyright © 2015 the American Physiological Society.

Phrenic Nerve Transfer for Reconstruction of Elbow Extension in Severe Brachial Plexus Injuries.

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Flores, Leandro P; Socolovsky, Mariano

2016-09-01

Background Restoring elbow extension is an important objective to pursue when repairing the brachial plexus in patients with a flail arm. Based upon the good results obtained using the phrenic nerve to restore elbow flexion and shoulder stability, we hypothesized that this nerve could also be employed to reconstruct elbow extension in patients with severe brachial plexus injuries. Methods A retrospective study of 10 patients in which the phrenic nerve targeted the radial nerve (7 patients) or the branch to the long head of the triceps (3 patients) as a surgical strategy for reconstruction of the brachial plexus. Results The mean postoperative follow-up time was 34 months. At final follow-up, elbow extension graded as M4 was measured in three patients, Medical Research Council MRC M3 in five patients, and M2 in one patient, while one patient experienced no measurable recovery (M0). No patient complained or demonstrated any signs of respiratory insufficiency postoperatively. Conclusions The phrenic nerve is a reliable donor for reanimation of elbow extension in such cases, and the branch to the long head of the triceps should be considered as a better target for the nerve transfer. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Genetic deficiency of GABA differentially regulates respiratory and non-respiratory motor neuron development.

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Matthew J Fogarty

Full Text Available Central nervous system GABAergic and glycinergic synaptic activity switches from postsynaptic excitation to inhibition during the stage when motor neuron numbers are being reduced, and when synaptic connections are being established onto and by motor neurons. In mice this occurs between embryonic (E day 13 and birth (postnatal day 0. Our previous work on mice lacking glycinergic transmission suggested that altered motor neuron activity levels correspondingly regulated motor neuron survival and muscle innervation for all respiratory and non respiratory motor neuron pools, during this period of development [1]. To determine if GABAergic transmission plays a similar role, we quantified motor neuron number and the extent of muscle innervation in four distinct regions of the brain stem and spinal cord; hypoglossal, phrenic, brachial and lumbar motor pools, in mice lacking the enzyme GAD67. These mice display a 90% drop in CNS GABA levels ( [2]; this study. For respiratory-based motor neurons (hypoglossal and phrenic motor pools, we have observed significant drops in motor neuron number (17% decline for hypoglossal and 23% decline for phrenic and muscle innervations (55% decrease. By contrast for non-respiratory motor neurons of the brachial lateral motor column, we have observed an increase in motor neuron number (43% increase and muscle innervations (99% increase; however for more caudally located motor neurons within the lumbar lateral motor column, we observed no change in either neuron number or muscle innervation. These results show in mice lacking physiological levels of GABA, there are distinct regional changes in motor neuron number and muscle innervation, which appear to be linked to their physiological function and to their rostral-caudal position within the developing spinal cord. Our results also suggest that for more caudal (lumbar regions of the spinal cord, the effect of GABA is less influential on motor neuron development compared to

Robotic phrenic nerve harvest: a feasibility study in a pig model.

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Porto de Melo, P; Miyamoto, H; Serradori, T; Ruggiero Mantovani, G; Selber, J; Facca, S; Xu, W-D; Santelmo, N; Liverneaux, P

2014-10-01

The aim of this study was to report on the feasibility of robotic phrenic nerve harvest in a pig model. A surgical robot (Da Vinci S™ system, Intuitive Surgical(®), Sunnyvale, CA) was installed with three ports on the pig's left chest. The phrenic nerve was transected distally where it enters the diaphragm. The phrenic nerve harvest was successfully performed in 45 minutes without major complications. The advantages of robotic microsurgery for phrenic nerve harvest are the motion scaling up to 5 times, elimination of physiological tremor, and free movement of joint-equipped robotic arms. Robot-assisted neurolysis may be clinically useful for harvesting the phrenic nerve for brachial plexus reconstruction. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Chitosan tubes can restore the function of resected phrenic nerves.

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Tanaka, Nobuyoshi; Matsumoto, Isao; Suzuki, Mitsutaka; Kaneko, Mami; Nitta, Kanae; Seguchi, Ryuta; Ooi, Akishi; Takemura, Hirofumi

2015-07-01

We previously reported that the phrenic nerve could be morphologically repaired by implantation of a chitosan nanofibre tube (C-tube). In the current study, we investigated whether implantation of C-tubes could improve the function of an injured phrenic nerve using a beagle dog model. Seven beagle dogs underwent right thoracotomy under general anaesthesia. An approximately 5 mm length of the right phrenic nerve was resected. Five dogs had a C-tube implantation (C-tube group) and other two dogs did not have the C-tube implantation (control group). Diaphragm movements were longitudinally measured by X-ray fluoroscopy before surgery, immediately after the surgery, and 3, 6 and 12 months after the surgery. The diaphragm movement was determined by diaphragm levels at inspiration and expiration phases, and the excursion difference between them was calculated. At 12 months after the surgery, rethoracotomy was performed to examine electrical phrenic nerve conduction. The C-tube and phrenic nerve were then excised for histological assessment of nerve regeneration. Three of the five animals of the C-tube group showed improvement of diaphragm movement with time. In these three animals, slow phrenic nerve conduction was observed. Histological assessment showed that the injured nerve was connected by newly regenerating nerve fibres surrounded by granulation tissue within the C-tube. On the other hand, the animals in the control group and two animals of the C-tube group showed neither improved diaphragm movement, nor electrical conduction to the diaphragm. No nerve fibre regeneration was found by histology. Our results suggest that, in addition to morphological improvement, C-tube implantation can functionally improve the injured phrenic nerve by promoting phrenic nerve regeneration. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Diaphragmatic height index: new diagnostic test for phrenic nerve dysfunction.

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Pornrattanamaneewong, Chaturong; Limthongthang, Roongsak; Vathana, Torpon; Kaewpornsawan, Kamolporn; Songcharoen, Panupan; Wongtrakul, Saichol

2012-11-01

The diaphragmatic height index (DHI) was developed to measure the difference in diaphragm levels. The purpose of this study was to set definite DHI values and test the accuracy of these values for use as a new diagnostic test for phrenic nerve dysfunction. All data for this study were obtained from medical charts and retrospectively reviewed. One hundred sixty-five patients with brachial plexus injury who had undergone nerve transfers between 2005 and 2008 were divided into Groups A and B. Group A consisted of 40 patients (mean age 28.0 years) who had sustained concomitant injury of the brachial plexus and phrenic nerves. Patients in Group A1 had right phrenic nerve injury and those in Group A2 had left phrenic nerve injury. Intraoperative direct electrical stimulation of the phrenic nerve was considered the gold standard in assessing nerve function in all patients with brachial plexus injury. Group B consisted of 125 patients (mean age 28.7 years) with brachial plexus injury and normal phrenic nerve function. Group C, the control group, consisted of 80 patients with nonbrachial plexus injury (mean age 34.0 years) who had undergone other kinds of orthopedic operations between April and June 2009. Standard posteroanterior chest radiographs were blindly interpreted using the Siriraj inhouse picture archiving and communication system in all 245 patients in the study. First, a reference line (R line) was drawn along the inferior endplate of T-10. Then, 2 lines (lines A and B) were drawn through the highest point of each diaphragm and parallel to the R line. The difference between these 2 lines divided by the height of T-10 was defined as the DHI. The cutoff points of the DHI for diagnosing right and left phrenic nerve dysfunction were analyzed with a receiver operating characteristic curve. The accuracy of these DHI values was then evaluated. The DHI in Group C was 0.64 ± 0.44, slightly higher than the DHI in Group B, with no significant difference. Diaphragmatic

Phrenic nerves and diaphragms in sudden infant death syndrome.

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Weis, J; Weber, U; Schröder, J M; Lemke, R; Althoff, H

1998-01-30

Disturbances of the respiratory system may be an important factor in the cascade of events leading to sudden infant death syndrome (SIDS). Even though the diaphragm is the major respiratory muscle in infants, little is known about alterations of this muscle and of the phrenic nerve in SIDS. In the present study, diaphragms and phrenic nerves of 24 SIDS infants and seven controls were analyzed. Morphometric analysis revealed only slightly larger cross sectional areas of phrenic nerve axons but no increase in myelin sheath thickness in SIDS cases. However, in one SIDS case, myelinated nerve fibre density was severely reduced. Using electron microscopy, several nerve fibres of SIDS infants showed focal accumulations of neurofilaments. Muscle fibre diameters in SIDS diaphragms were significantly larger compared to controls (P fibre ruptures and contracture bands were found. These prominent nonspecific ultrastructural alterations should advise caution in the interpretation of morphometric data. Thus, in some cases exemplified by one case of the present series, decreased density of phrenic nerve myelinated axons might contribute to SIDS. Still, the present results indicate that development of phrenic nerves and diaphragms is not delayed in most SIDS infants.

Inferior phrenic artery embolization in the treatment of hepatic neoplasms

International Nuclear Information System (INIS)

Duprat, G.; Charnsangavej, C.; Wallace, S.; Carrasco, C.H.

1988-01-01

Twenty-nine inferior phrenic artery embolizations were performed in 20 patients with primary or metastatic hepatic neoplasms. All patients had interruption of their hepatic arteries by previous infusion of chemotherapy, hepatic arterial embolization or surgical ligation. In one patient, bilateral pleural effusions developed following embolization of the inferior phrenic artery. No other severe complications occurred. Inferior phrenic artery embolization is a safe procedure and permits the continuation of transcatheter treatment of hepatic neoplasms. (orig.)

Inferior phrenic artery embolization in the treatment of hepatic neoplasms

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Duprat, G.; Charnsangavej, C.; Wallace, S.; Carrasco, C.H.

Twenty-nine inferior phrenic artery embolizations were performed in 20 patients with primary or metastatic hepatic neoplasms. All patients had interruption of their hepatic arteries by previous infusion of chemotherapy, hepatic arterial embolization or surgical ligation. In one patient, bilateral pleural effusions developed following embolization of the inferior phrenic artery. No other severe complications occurred. Inferior phrenic artery embolization is a safe procedure and permits the continuation of transcatheter treatment of hepatic neoplasms.

Phrenic nerve deficits and neurological immunopathology associated with acute West Nile virus infection in mice and hamsters.

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Zukor, Katherine; Wang, Hong; Hurst, Brett L; Siddharthan, Venkatraman; Van Wettere, Arnaud; Pilowsky, Paul M; Morrey, John D

2017-04-01

Neurological respiratory deficits are serious outcomes of West Nile virus (WNV) disease. WNV patients requiring intubation have a poor prognosis. We previously reported that WNV-infected rodents also appear to have respiratory deficits when assessed by whole-body plethysmography and diaphragmatic electromyography. The purpose of this study was to determine if the nature of the respiratory deficits in WNV-infected rodents is neurological and if deficits are due to a disorder of brainstem respiratory centers, cervical spinal cord (CSC) phrenic motor neuron (PMN) circuitry, or both. We recorded phrenic nerve (PN) activity and found that in WNV-infected mice, PN amplitude is reduced, corroborating a neurological basis for respiratory deficits. These results were associated with a reduction in CSC motor neuron number. We found no dramatic deficits, however, in brainstem-mediated breathing rhythm generation or responses to hypercapnia. PN frequency and pattern parameters were normal, and all PN parameters changed appropriately upon a CO 2 challenge. Histological analysis revealed generalized microglia activation, astrocyte reactivity, T cell and neutrophil infiltration, and mild histopathologic lesions in both the brainstem and CSC, but none of these were tightly correlated with PN function. Similar results in PN activity, brainstem function, motor neuron number, and histopathology were seen in WNV-infected hamsters, except that histopathologic lesions were more severe. Taken together, the results suggest that respiratory deficits in acute WNV infection are primarily due to a lower motor neuron disorder affecting PMNs and the PN rather than a brainstem disorder. Future efforts should focus on markers of neuronal dysfunction, axonal degeneration, and myelination.

Vocal cord collapse during phrenic nerve-paced respiration in congenital central hypoventilation syndrome.

Science.gov (United States)

Domanski, Mark C; Preciado, Diego A

2012-01-01

Phrenic nerve pacing can be used to treat congenital central hypoventilation syndrome (CCHS). We report how the lack of normal vocal cord tone during phrenic paced respiration can result in passive vocal cord collapse and produce obstructive symptoms. We describe a case of passive vocal cord collapse during phrenic nerve paced respiration in a patient with CCHS. As far as we know, this is the first report of this etiology of airway obstruction. The patient, a 7-year-old with CCHS and normal waking vocal cord movement, continued to require nightly continuous positive airway pressure (CPAP) despite successful utilization of phrenic nerve pacers. On direct laryngoscopy, the patient's larynx was observed while the diaphragmatic pacers were sequentially engaged. No abnormal vocal cord stimulation was witnessed during engaging of either phrenic nerve stimulator. However, the lack of normal inspiratory vocal cord abduction during phrenic nerve-paced respiration resulted in vocal cord collapse and partial obstruction due to passive adduction of the vocal cords through the Bernoulli effect. Bilateral phrenic nerve stimulation resulted in more vocal cord collapse than unilateral stimulation. The lack of vocal cord abduction on inspiration presents a limit to phrenic nerve pacers.

Phrenic paralysis during cardiac electronic device implantation: incidence, causes and clinical course.

Science.gov (United States)

López-Gil, María; Fontenla, Adolfo; Juliá, Justo; Parra, Juan José; Arribas, Fernando

2016-10-01

Phrenic paralysis is a known complication of central venous catheterization, but it is not listed as a complication related to cardiac implantable electronic device (CIED) implants. The aim of this study is to describe the incidence, causes, clinical picture, and management of phrenic paralysis occurring in this scenario. We retrospectively analysed data from our CIED implantation database and identified those patients who suffered phrenic paralysis during the implantation procedure. Four of 891 patients (subclavian puncture in 626) developed phrenic paralysis during pacemaker or defibrillator implant procedures. Severe respiratory failure needing ventilatory support occurred in two, being the phrenic paralysis transient in all of the cases. Transient phrenic paralysis may occur during CIED implantation probably related to the infiltration of local anaesthesia in the subclavian area. Mechanism, prevention, and management are discussed. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Ultrasound-guided continuous phrenic nerve block for persistent hiccups.

NARCIS (Netherlands)

Renes, S.H.; Geffen, G.J. van; Rettig, H.C.; Gielen, M.J.M.; Scheffer, G.J.

2010-01-01

BACKGROUND: Phrenic nerve block can be performed and repeated if necessary for persistent hiccups, when conservative and pharmacological treatment is unsuccessful. We report the first description of an in-plane ultrasound (US)-guided phrenic nerve block (PhNB) with a catheter, after US investigation

Phrenic nerve injury after radiofrequency ablation of lung tumors: retrospective evaluation of the incidence and risk factors.

Science.gov (United States)

Matsui, Yusuke; Hiraki, Takao; Gobara, Hideo; Uka, Mayu; Masaoka, Yoshihisa; Tada, Akihiro; Toyooka, Shinichi; Mitsuhashi, Toshiharu; Mimura, Hidefumi; Kanazawa, Susumu

2012-06-01

To retrospectively investigate the incidence of and risk factors for phrenic nerve injury after radiofrequency (RF) ablation of lung tumors. The study included 814 RF ablation procedures of lung tumors. To evaluate the development of phrenic nerve injury, chest radiographs obtained before and after the procedure were examined. Phrenic nerve injury was assumed to have developed if the diaphragmatic level was elevated after the procedure. To identify risk factors for phrenic nerve injury, multiple variables were compared between cases of phrenic nerve injury and randomly selected controls by using univariate analyses. Multivariate analysis was then performed to identify independent risk factors. Evaluation of phrenic nerve injury from chest radiographs was possible after 786 procedures. Evidence of phrenic nerve injury developed after 10 cases (1.3%). Univariate analysis revealed that larger tumor size (≥ 20 mm; P = .014), proximity of the phrenic nerve to the tumor (phrenic nerve injury. Multivariate analysis demonstrated that the proximity of the phrenic nerve to the tumor (phrenic nerve injury after RF ablation was 1.3%. The proximity of the phrenic nerve to the tumor was an independent risk factor for phrenic nerve injury. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

Ultrasound-Guided Phrenic Nerve Block for Intractable Hiccups following Placement of Esophageal Stent for Esophageal Squamous Cell Carcinoma.

Science.gov (United States)

Arsanious, David; Khoury, Spiro; Martinez, Edgar; Nawras, Ali; Filatoff, Gregory; Ajabnoor, Hossam; Darr, Umar; Atallah, Joseph

2016-05-01

Hiccups are actions consisting of sudden contractions of the diaphragm and intercostals followed by a sudden inspiration and transient closure of the vocal cords. They are generally short lived and benign; however, in extreme and rare cases, such as esophageal carcinoma, they can become persistent or intractable, up to and involving significant pain, dramatically impacting the patient's quality of life. This case involves a 60-year-old man with a known history of squamous cell carcinoma of the esophagus. He was considered to have high surgical risk, and therefore he received palliative care through the use of fully covered metallic esophageal self-expandable stents due to a spontaneous perforated esophagus, after which he developed intractable hiccups and associated mediastinal pain. Conservative treatment, including baclofen, chlorpromazine, metoclopramide, and omeprazole, provided no relief for his symptoms. The patient was referred to pain management from gastroenterology for consultation on pain control. He ultimately received an ultrasound-guided left phrenic nerve block with bupivacaine and depomedrol, and 3 days later underwent the identical procedure on the right phrenic nerve. This led to complete resolution of his hiccups and associated mediastinal pain. At follow-up, 2 and 4 weeks after the left phrenic nerve block, the patient was found to maintain complete alleviation of the hiccups. Esophageal dilatation and/or phrenic or vagal afferent fiber irritation can be suspected in cases of intractable hiccups secondary to esophageal stenting. Regional anesthesia of the phrenic nerve through ultrasound guidance offers a long-term therapeutic option for intractable hiccups and associated mediastinal pain in selected patients with esophageal carcinoma after stent placement. Esophageal stent, esophageal stenting, intractable hiccups, intractable singultus, phrenic nerve block, phrenic nerve, ultrasound, palliative care, esophageal carcinoma.

The Mid-Term Changes of Pulmonary Function Tests After Phrenic Nerve Transfer.

Science.gov (United States)

Yavari, Masoud; Hassanpour, Seyed Esmail; Khodayari, Mohammad

2016-03-01

In the restoration of elbow flexion, the phrenic nerve has proven to be a good donor, but considering the role of the phrenic nerve in respiratory function, we cannot disregard the potential dangers of this method. In the current study, we reviewed the results of pulmonary function tests (PFT) in four patients who underwent phrenic nerve transfer. We reviewed the results of serial spirometry tests, which were performed before and after phrenic nerve transfer surgery. All patients regained Biceps power to M3 strength or above. None of our patients experienced pulmonary problems or respiratory complaints, but a significant reduction of spirometric parameters occurred after surgery. This study highlights the close link between the role of the phrenic nerve and pulmonary function, such that the use of this nerve as a transfer donor leads to spirometric impairments.

Early uneven ear input induces long-lasting differences in left-right motor function.

Science.gov (United States)

Antoine, Michelle W; Zhu, Xiaoxia; Dieterich, Marianne; Brandt, Thomas; Vijayakumar, Sarath; McKeehan, Nicholas; Arezzo, Joseph C; Zukin, R Suzanne; Borkholder, David A; Jones, Sherri M; Frisina, Robert D; Hébert, Jean M

2018-03-01

How asymmetries in motor behavior become established normally or atypically in mammals remains unclear. An established model for motor asymmetry that is conserved across mammals can be obtained by experimentally inducing asymmetric striatal dopamine activity. However, the factors that can cause motor asymmetries in the absence of experimental manipulations to the brain remain unknown. Here, we show that mice with inner ear dysfunction display a robust left or right rotational preference, and this motor preference reflects an atypical asymmetry in cortico-striatal neurotransmission. By unilaterally targeting striatal activity with an antagonist of extracellular signal-regulated kinase (ERK), a downstream integrator of striatal neurotransmitter signaling, we can reverse or exaggerate rotational preference in these mice. By surgically biasing vestibular failure to one ear, we can dictate the direction of motor preference, illustrating the influence of uneven vestibular failure in establishing the outward asymmetries in motor preference. The inner ear-induced striatal asymmetries identified here intersect with non-ear-induced asymmetries previously linked to lateralized motor behavior across species and suggest that aspects of left-right brain function in mammals can be ontogenetically influenced by inner ear input. Consistent with inner ear input contributing to motor asymmetry, we also show that, in humans with normal ear function, the motor-dominant hemisphere, measured as handedness, is ipsilateral to the ear with weaker vestibular input.

The evaluation of the right inferior phrenic artery diameter in cirrhotic patients.

Science.gov (United States)

Esen, Kaan; Balci, Yuksel; Tok, Sermin; Ucbilek, Enver; Kara, Engin; Kaya, Omer

2017-09-01

The purpose of this study is to evaluate the relationship between right inferior phrenic artery diameter and portal hypertension in cirrhotic patients. CT examinations of 38 patients with chronic liver disease (patient group) and 40 patients without any liver disease (control group) were evaluated. The right inferior phrenic artery diameter of the patient and control group were measured. CT findings of portal hypertension, which were accepted as ascites, collaterals, splenomegaly and portal vein diameter greater than 13 mm, were determined and scored in the patient group. Patients obtained scores between one and four with respect to portal hypertension findings, and the scores were compared with phrenic artery diameters. Child-Pugh and MELD scores of the patients were also calculated. The mean diameter of the right inferior phrenic artery in the patient group was larger than that in the control group (p phrenic artery diameter of the patients with score 1 was significantly different from those with score 2 (p = 0.028), score 3 (p = 0.001) and score 4 (p = 0.005). We found a linear and moderate relationship between phrenic artery diameter values and Child-Pugh scores (p = 0.012, r = 0.405). Dilatation of the right inferior phrenic artery in cirrhotic patients may be a nonspecific sign of developing portal hypertension.

Neurofibromas of the Phrenic Nerve: A Case Report and Review of the Literature.

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Ghali, Michael G Z; Srinivasan, Visish M; Jea, Andrew; Slopis, John M; McCutcheon, Ian E

2016-04-01

Phrenic neurofibromas are a rare pathologic entity, with 9 cases described in the English literature. They may occur in conjunction with or independently of neurofibromatosis type 1. Phrenic neurofibromas pose distinct therapeutic challenges compared with the more common phrenic schwannoma. We describe here a 12-year-old boy with neurofibroma of the left phrenic nerve presenting as dextroposition of the heart after paralysis of the left hemidiaphragm allowed herniation of abdominal contents into the left hemithorax and displaced the heart. Surgical resection of the tumor followed by diaphragmatic plication was performed to assess its degree of malignancy, reduce abdominal herniation, and improve lung capacity. The operation markedly improved his hemidiaphragmatic elevation. The spectrum of management options ranges from conservative surveillance to open thoracic surgery. Functional preservation of the phrenic nerve is technically challenging, and although phrenic neurofibromas often present with absent function that cannot be recovered, surgical intervention can be fruitful in restoring lung capacity through diaphragmatic reconstruction. Copyright © 2016 Elsevier Inc. All rights reserved.

Phrenic Nerve Reconstruction and Bilateral Diaphragm Plication After Lobectomy.

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Shinohara, Shuichi; Yamada, Tetsu; Ueda, Mitsuhiro; Ishinagi, Hiroyoshi; Matsuoka, Takahisa; Nagai, Shinjiro; Matsuoka, Katsunari; Miyamoto, Yoshihiro

2017-07-01

A 49-year-old man with left phrenic nerve paralysis caused by mediastinal tumor resection 28 years earlier was found to have a nodule in the right upper lobe. The right phrenic nerve was severed during right upper lobectomy but was reconstructed along with bilateral plication of the diaphragm. The patient was weaned from the ventilator during the daytime on postoperative day 13 and was discharged home on postoperative day 48. Three months postoperatively, chest fluoroscopic imaging showed recovery of movement of the right diaphragm. Nerve conduction studies showed improvement of function of the reconstructed right phrenic nerve. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Massive hemothorax due to inferior phrenic artery injury after blunt trauma.

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Aoki, Makoto; Shibuya, Kei; Kaneko, Minoru; Koizumi, Ayana; Murata, Masato; Nakajima, Jun; Hagiwara, Shuichi; Kanbe, Masahiko; Koyama, Yoshinori; Tsushima, Yoshito; Oshima, Kiyohiro

2015-01-01

Injury to the inferior phrenic artery after blunt trauma is an extremely rare event, and it may occur under unanticipated conditions. This case report describes an injury to the left inferior phrenic artery caused by blunt trauma, which was complicated by massive hemothorax, and treated with transcatheter arterial embolization (TAE). An 81 year-old female hit by a car while walking at the traffic intersection was transferred to the emergency department, computed tomography scanning revealed active extravasations of the contrast medium within the retrocrural space and from branches of the internal iliac artery. The patient underwent repeated angiography, and active extravasation of contrast medium was observed between the retrocrural space and the right pleural space originating from the left inferior phrenic artery. The injured left inferior phrenic artery was successfully embolized with N-butyl cyanoacrylate, resulting in stabilization of the patient's clinical condition. Inferior phrenic artery injury should be recognized as a rare phenomenon and causative factor for hemothorax. TAE represents a safe and effective treatment for this complication and obviates the need for a thoracotomy.

Direct Coaptation of the Phrenic Nerve With the Posterior Division of the Lower Trunk to Restore Finger and Elbow Extension Function in Patients With Total Brachial Plexus Injuries.

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Wang, Shu-feng; Li, Peng-cheng; Xue, Yun-hao; Zou, Ji-yao; Li, Wen-jun; Li, Yucheng

2016-02-01

To overcome the mismatch in nerve sizes in phrenic nerve transfer to the radial nerve for elbow and finger extension reanimation for patients with total brachial plexus injuries (TBPI), a selective neurotization procedure was designed. To investigate the long-term results of phrenic nerve transfer to the posterior division of the lower trunk with direct coaptation in restoring elbow and finger extension after TBPI. Phrenic nerve was transferred to and directly coapted with the posterior division of the lower trunk in 27 patients with TBPI. Seven patients were <18 years old (adolescent group), and the remaining 20 patients ≥18 years (adult group). Postoperative mean follow-up period was 54 ± 9 months (range, 48-85 months). The motor function attained M3 or greater in 81.5% of patients for elbow extension and in 48% of patients for finger extension. The percentage of patients who regained M3 or greater muscle power of finger extension in the adolescent group and the adult group was 71.4%, and 40%, respectively. Meanwhile, 85.7% in the adolescent group and 80% in the adult group achieved M3 or greater muscle power of elbow extension. There were no significant differences between the 2 groups. The elbow extension and finger extension were synchronous contractions and did not become independent of respiratory effort. This procedure simultaneously and effectively restores the function of elbow and finger extension in patients after TBPI. However, the patients could not do elbow and finger extension separately.

Reinnervation of the diaphragm by the inferior laryngeal nerve to the phrenic nerve in ventilator-dependent tetraplegic patients with C3-5 damage.

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Verin, Eric; Morelot-Panzini, Capucine; Gonzalez-Bermejo, Jesus; Veber, Benoit; Perrouin Verbe, Brigitte; Soudrie, Brigitte; Leroi, Anne Marie; Marie, Jean Paul; Similowski, Thomas

2017-10-01

The aim of this study was to evaluate the feasibility of unilateral diaphragmatic reinnervation in humans by the inferior laryngeal nerve. This pilot study included chronically ventilated tetraplegic patients with destruction of phrenic nerve motoneurons. Five patients were included. They all had a high level of tetraplegia, with phrenic nerve motor neuron destruction. They were highly dependent on ventilation, without any possibility of weaning. They did not have other chronic pathologies, especially laryngeal disease. They all had diaphragmatic explorations to diagnose the destruction of the motoneurons of the phrenic nerves and nasoendoscopy to be sure that they did not have laryngeal or pharyngeal disease. Then, surgical anastomosis of the right phrenic nerve was performed with the inferior laryngeal nerve, by a cervical approach. A laryngeal reinnervation was performed at the same time, using the ansa hypoglossi. One patient was excluded because of a functional phrenic nerve and one patient died 6 months after the surgery of a cardiac arrest. The remaining three patients were evaluated after the anastomosis every 6 months. They did not present any swallowing or vocal alterations. In these three patients, the diaphragmatic explorations showed that there was a recovery of the diaphragmatic electromyogram of the right and left hemidiaphragms after 1 year. Two patients had surgical diaphragmatic explorations for diaphragmatic pacing 18-24 months after the reinnervation with excellent results. At 36 months, none of the patients could restore their automatic ventilation. In conclusion, this study demonstrated that diaphragmatic reinnervation by the inferior laryngeal nerve is effective, without any vocal or swallowing complications.

Thoracoscopic patch insulation to correct phrenic nerve stimulation secondary to cardiac resynchronization therapy.

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Mediratta, Neeraj; Barker, Diane; McKevith, James; Davies, Peter; Belchambers, Sandra; Rao, Archana

2012-07-01

Cardiac resynchronization therapy is an established therapy for heart failure, improving quality of life and prognosis. Despite advances in technique, available leads and delivery systems, trans-venous left ventricular (LV) lead positioning remains dependent on the patient's underlying venous anatomy. The left phrenic nerve courses over the surface of the pericardium laterally and may be stimulated by the LV pacing lead, causing uncomfortable diaphragmatic twitch. This paper describes a video-assisted thoracoscopic (VATS) procedure to correct phrenic nerve stimulation secondary to cardiac resynchronization therapy. Most current ways of avoiding phrenic stimulation involve either electronic reprogramming to distance the phrenic nerve from the stimulation circuit or repositioning the lead. We describe a case where the phrenic nerve was surgically insulated from the stimulating current by insinuating a patch of bovine pericardium between the epicardium and native pericardium of the heart thus completely resolving previously intolerable and incessant diaphragmatic twitch. The procedure was performed under general anaesthesia with single-lung ventilation and minimal use of neuromuscular blocking agents. Surgical patch insulation of the phrenic nerve was performed using minimally invasive VATS surgery, as a short-stay procedure, with no complications. No diaphragmatic twitch occurred post-surgery and the patient continued to gain symptomatic benefit from cardiac synchronization therapy (New York Heart Association Class III to II), enabling return to work. In cases where the trans-venous position of a LV lead is limited by troublesome phrenic nerve stimulation, thoracoscopic surgical patch insulation of the phrenic nerve could be considered to allow beneficial cardiac resynchronization therapy.

Mapping of the left-sided phrenic nerve course in patients undergoing left atrial catheter ablations.

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Huemer, Martin; Wutzler, Alexander; Parwani, Abdul S; Attanasio, Philipp; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

2014-09-01

Catheter ablation of atrial fibrillation has been associated with left-sided phrenic nerve palsy. Knowledge of the individual left phrenic nerve course therefore is essential to prevent nerve injury. The aim of this study was to test the feasibility of an intraprocedural pace mapping and reconstruction of the left phrenic nerve course and to characterize which anatomical areas are affected. In patients undergoing left atrial catheter ablation, a three-dimensional map of the left atrial anatomical structures was created. The left-sided phrenic nerve course was determined by high-output pace mapping and reconstructed in the map. In this study, 40 patients with atrial fibrillation or atrial tachycardias were included. Left phrenic nerve capture was observed in 23 (57.5%) patients. Phrenic nerve was captured in 22 (55%) patients inside the left atrial appendage, in 22 (55%) in distal parts, in 21 (53%) in medial parts, and in two (5%) in ostial parts of the appendage. In three (7.5%) patients, capture was found in the distal coronary sinus and in one (2.5%) patient in the left atrium near the left atrial appendage ostium. Ablation target was changed due to direct spatial relationship to the phrenic nerve in three (7.5%) patients. No phrenic nerve palsy was observed. Left-sided phrenic nerve capture was found inside and around the left atrial appendage in the majority of patients and additionally in the distal coronary sinus. Phrenic nerve mapping and reconstruction can easily be performed and should be considered prior catheter ablations in potential affected areas. ©2014 Wiley Periodicals, Inc.

Electrophysiological evaluation of phrenic nerve injury during cardiac surgery – a prospective, controlled, clinical study

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Ege Turan

2004-01-01

Full Text Available Abstract Background According to some reports, left hemidiaphragmatic paralysis due to phrenic nerve injury may occur following cardiac surgery. The purpose of this study was to document the effects on phrenic nerve injury of whole body hypothermia, use of ice-slush around the heart and mammary artery harvesting. Methods Electrophysiology of phrenic nerves was studied bilaterally in 78 subjects before and three weeks after cardiac or peripheral vascular surgery. In 49 patients, coronary artery bypass grafting (CABG and heart valve replacement with moderate hypothermic (mean 28°C cardiopulmonary bypass (CPB were performed. In the other 29, CABG with beating heart was performed, or, in several cases, peripheral vascular surgery with normothermia. Results In all patients, measurements of bilateral phrenic nerve function were within normal limits before surgery. Three weeks after surgery, left phrenic nerve function was absent in five patients in the CPB and hypothermia group (3 in CABG and 2 in valve replacement. No phrenic nerve dysfunction was observed after surgery in the CABG with beating heart (no CPB or the peripheral vascular groups. Except in the five patients with left phrenic nerve paralysis, mean phrenic nerve conduction latency time (ms and amplitude (mV did not differ statistically before and after surgery in either group (p > 0.05. Conclusions Our results indicate that CPB with hypothermia and local ice-slush application around the heart play a role in phrenic nerve injury following cardiac surgery. Furthermore, phrenic nerve injury during cardiac surgery occurred in 10.2 % of our patients (CABG with CPB plus valve surgery.

Anatomical study of phrenic nerve course in relation to neck dissection.

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Hamada, Tomohiro; Usami, Akinobu; Kishi, Asuka; Kon, Hideki; Takada, Satoshi

2015-04-01

The present study sought to clarify the course of the phrenic nerve and its correlation with anatomical landmarks in the neck region. We examined 17 cadavers (30 sides). In each, the phrenic nerves was dissected from the lateral side of the neck, and its position within the triangle formed by the mastoid process and sternal and acromial ends of the clavicle was determined. The point where the phrenic nerve arises in the posterior triangle was found to be similar to the point where the cutaneous blanches of the cervical plexus emerge at the middle of the posterior border of the sternocleidomastoid muscle. In the supraclavian triangle, the phrenic nerve crosses the anterior border of the anterior scalene muscle near Erb's point where the superficial point is 2-3 cm superior from the clavicle and posterior border of the sternocleidomastoid muscle. The phrenic nerve arises in the posterior triangle near the nerve point, then descends to the anterior surface of the anterior scalene muscle in the supraclavian triangle. It is necessary to be aware of the supraclavian triangle below Erb's point during neck dissection procedures.

Functional restoration of diaphragmatic paralysis: an evaluation of phrenic nerve reconstruction.

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Kaufman, Matthew R; Elkwood, Andrew I; Colicchio, Alan R; CeCe, John; Jarrahy, Reza; Willekes, Lourens J; Rose, Michael I; Brown, David

2014-01-01

Unilateral diaphragmatic paralysis causes respiratory deficits and can occur after iatrogenic or traumatic phrenic nerve injury in the neck or chest. Patients are evaluated using spirometry and imaging studies; however, phrenic nerve conduction studies and electromyography are not widely available or considered; thus, the degree of dysfunction is often unknown. Treatment has been limited to diaphragmatic plication. Phrenic nerve operations to restore diaphragmatic function may broaden therapeutic options. An interventional study of 92 patients with symptomatic diaphragmatic paralysis assigned 68 (based on their clinical condition) to phrenic nerve surgical intervention (PS), 24 to nonsurgical (NS) care, and evaluated a third group of 68 patients (derived from literature review) treated with diaphragmatic plication (DP). Variables for assessment included spirometry, the Short-Form 36-Item survey, electrodiagnostics, and complications. In the PS group, there was an average 13% improvement in forced expiratory volume in 1 second (p Phrenic nerve operations for functional restoration of the paralyzed diaphragm should be part of the standard treatment algorithm in the management of symptomatic patients with this condition. Assessment of neuromuscular dysfunction can aid in determining the most effective therapy. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Sonoanatomical Change of Phrenic Nerve According to Posture During Ultrasound-Guided Stellate Ganglion Block.

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Joeng, Eui Soo; Jeong, Young Cheol; Park, Bum Jun; Kang, Seok; Yang, Seung Nam; Yoon, Joon Shik

2016-04-01

To evaluate the risk of phrenic nerve injury during ultrasound-guided stellate ganglion block (US-SGB) according to sonoanatomy of the phrenic nerve, and determine a safer posture for needle insertion by assessing its relationship with surrounding structure according to positional change. Twenty-nine healthy volunteers were recruited and underwent ultrasound in two postures, i.e., supine position with the neck extension and head rotation, and lateral decubitus position. The transducer was placed at the anterior tubercle of the C6 level to identify phrenic nerve. The cross-sectional area (CSA), depth from skin, distance between phrenic nerve and anterior tubercle of C6 transverse process, and the angle formed by anterior tubercle, posterior tubercle and phrenic nerve were measured. The phrenic nerve was clearly identified in the intermuscular fascia layer between the anterior scalene and sternocleidomastoid muscles. The distance between the phrenic nerve and anterior tubercle was 10.33±3.20 mm with the supine position and 9.20±3.31 mm with the lateral decubitus position, respectively. The mean CSA and skin depth of phrenic nerve were not statistically different between the two positions. The angle with the supine position was 48.37°±27.43°, and 58.89°±30.02° with the lateral decubitus position. The difference of angle between the two positions was statistically significant. Ultrasound is a useful tool for assessing the phrenic nerve and its anatomical relation with other cervical structures. In addition, lateral decubitus position seems to be safer by providing wider angle for needle insertion than the supine position in US-SGB.

GABA, not glycine, mediates inhibition of latent respiratory motor pathways after spinal cord injury

OpenAIRE

Zimmer, M. Beth; Goshgarian, Harry G.

2006-01-01

Previous work has shown that latent respiratory motor pathways known as crossed phrenic pathways are inhibited via a spinal inhibitory process; however, the underlying mechanisms remain unknown. The present study investigated whether spinal GABA-A and/or glycine receptors are involved in the inhibition of the crossed phrenic pathways after a C2 spinal cord hemisection injury. Under ketamine/xylazine anesthesia, adult, female, Sprague Dawley rats were hemisected at the C2 spinal cord level. Fo...

Distinct cerebellar engrams in short-term and long-term motor learning.

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Wang, Wen; Nakadate, Kazuhiko; Masugi-Tokita, Miwako; Shutoh, Fumihiro; Aziz, Wajeeha; Tarusawa, Etsuko; Lorincz, Andrea; Molnár, Elek; Kesaf, Sebnem; Li, Yun-Qing; Fukazawa, Yugo; Nagao, Soichi; Shigemoto, Ryuichi

2014-01-07

Cerebellar motor learning is suggested to be caused by long-term plasticity of excitatory parallel fiber-Purkinje cell (PF-PC) synapses associated with changes in the number of synaptic AMPA-type glutamate receptors (AMPARs). However, whether the AMPARs decrease or increase in individual PF-PC synapses occurs in physiological motor learning and accounts for memory that lasts over days remains elusive. We combined quantitative SDS-digested freeze-fracture replica labeling for AMPAR and physical dissector electron microscopy with a simple model of cerebellar motor learning, adaptation of horizontal optokinetic response (HOKR) in mouse. After 1-h training of HOKR, short-term adaptation (STA) was accompanied with transient decrease in AMPARs by 28% in target PF-PC synapses. STA was well correlated with AMPAR decrease in individual animals and both STA and AMPAR decrease recovered to basal levels within 24 h. Surprisingly, long-term adaptation (LTA) after five consecutive daily trainings of 1-h HOKR did not alter the number of AMPARs in PF-PC synapses but caused gradual and persistent synapse elimination by 45%, with corresponding PC spine loss by the fifth training day. Furthermore, recovery of LTA after 2 wk was well correlated with increase of PF-PC synapses to the control level. Our findings indicate that the AMPARs decrease in PF-PC synapses and the elimination of these synapses are in vivo engrams in short- and long-term motor learning, respectively, showing a unique type of synaptic plasticity that may contribute to memory consolidation.

A Novel Method to Prevent Phrenic Nerve Injury During Catheter Ablation

OpenAIRE

Buch, Eric; Vaseghi, Marmar; Cesario, David A; Shivkumar, Kalyanam

2006-01-01

Epicardial catheter ablation is increasingly important in the treatment of ventricular arrhythmias. Collateral damage to adjacent structures like the phrenic nerve is an important concern with epicardial ablation. This report describes the use of a novel method to prevent phrenic nerve injury during epicardial ablation of ventricular tachycardia.

A rare case of diaphragmatic paralysis due to isolated phrenic nerve ...

African Journals Online (AJOL)

2008-11-04

Nov 4, 2008 ... Isolated phrenic nerve palsy is a rare condition resulting from birth injury, with many possible complications such as diaphragmatic paralysis, pulmonary infection, chronic lung disease, growth failure and even death.1-3 I report a case of neonatal isolated phrenic nerve palsy in an infant delivered.

Subclavian vein pacing and venous pressure waveform measurement for phrenic nerve monitoring during cryoballoon ablation of atrial fibrillation.

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Ghosh, Justin; Singarayar, Suresh; Kabunga, Peter; McGuire, Mark A

2015-06-01

The phrenic nerves may be damaged during catheter ablation of atrial fibrillation. Phrenic nerve function is routinely monitored during ablation by stimulating the right phrenic nerve from a site in the superior vena cava (SVC) and manually assessing the strength of diaphragmatic contraction. However the optimal stimulation site, method of assessing diaphragmatic contraction, and techniques for monitoring the left phrenic nerve have not been established. We assessed novel techniques to monitor phrenic nerve function during cryoablation procedures. Pacing threshold and stability of phrenic nerve capture were assessed when pacing from the SVC, left and right subclavian veins. Femoral venous pressure waveforms were used to monitor the strength of diaphragmatic contraction. Stable capture of the left phrenic nerve by stimulation in the left subclavian vein was achieved in 96 of 100 patients, with a median capture threshold of 2.5 mA [inter-quartile range (IQR) 1.4-5.0 mA]. Stimulation of the right phrenic nerve from the subclavian vein was superior to stimulation from the SVC with lower pacing thresholds (1.8 mA IQR 1.4-3.3 vs. 6.0 mA IQR 3.4-8.0, P phrenic nerve palsy. The left phrenic nerve can be stimulated from the left subclavian vein. The subclavian veins are the optimal sites for phrenic nerve stimulation. Monitoring the femoral venous pressure waveform is a novel technique for detecting impending phrenic nerve damage. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Phrenic nerve palsy associated with birth trauma--case reports and a literature review.

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Shiohama, Tadashi; Fujii, Katsunori; Hayashi, Masaharu; Hishiki, Tomoro; Suyama, Maiko; Mizuochi, Hiromi; Uchikawa, Hideki; Yoshida, Shigetoshi; Yoshida, Hideo; Kohno, Yoichi

2013-04-01

Phrenic nerve palsy is a peripheral nerve disorder caused by excessive cervical extension due to birth trauma or cardiac surgery. We describe two new patients with phrenic nerve palsy associated with birth trauma. Both patients exhibited profound dyspnea and general hypotonia immediately after birth. A chest roentgenogram and fluoroscopy revealed elevation of the diaphragm, leading to a diagnosis of phrenic nerve palsy associated with birth trauma. Since they had intermittently exhibited dyspnea and recurrent infection, we performed video-assisted thoracoscopic surgery (VATS) plication in both cases, at an early and a late stage, respectively. Both patients subsequently exhibited a dramatic improvement in dyspnea and recurrent respiratory infection. Interestingly, the late stage operated infant exhibited spontaneous recovery at 7 months with cessation of mechanical ventilation once. However, this recovery was transient and subsequently led to an increased ventilation volume demand, finally resulting in surgical treatment at 15 months. Histological examination of the diaphragm at this time showed grouped muscle atrophy caused by phrenic nerve degeneration. To our knowledge, this is the first pathologically proven report of grouped muscle atrophy of the diaphragm due to phrenic nerve degeneration, suggesting that partial impairment of phrenic nerves resulted in respiratory dysfunction with incomplete recovery. We conclude that recently developed VATS plication is a safe and effective treatment for infants with phrenic nerve palsy, and should be considered as a surgical treatment at an early period. Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Evaluation of detectability of right inferior phrenic artery root in dynamic CT

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Sato, Osamu [Akashi Municipal Hospital, Hyogo (Japan); Kizu, Osamu; Shimizu, Toshihisa; Takahashi, Takeshi; Ohno, Koji; Ohmura, Makoto; Maeda, Tomoho

1995-05-01

We evaluated the detectability of the root of the right inferior phrenic artery in dynamic CT over the entire liver as used for the diagnosis of hepatocellular carcinoma. The results showed no detection in three cases, poor detection in seven, detection in 12 and good detection in eight. The right inferior phrenic artery could be detected in many cases. Identification was easier in cases with direct branching from the aorta. It can be concluded that for angiographic examination, dynamic CT over the entire liver is useful for catheterization to the right inferior phrenic artery. (author).

Evaluation of detectability of right inferior phrenic artery root in dynamic CT

International Nuclear Information System (INIS)

Sato, Osamu; Kizu, Osamu; Shimizu, Toshihisa; Takahashi, Takeshi; Ohno, Koji; Ohmura, Makoto; Maeda, Tomoho.

1995-01-01

We evaluated the detectability of the root of the right inferior phrenic artery in dynamic CT over the entire liver as used for the diagnosis of hepatocellular carcinoma. The results showed no detection in three cases, poor detection in seven, detection in 12 and good detection in eight. The right inferior phrenic artery could be detected in many cases. Identification was easier in cases with direct branching from the aorta. It can be concluded that for angiographic examination, dynamic CT over the entire liver is useful for catheterization to the right inferior phrenic artery. (author)

Phrenic Nerve Injury After Catheter Ablation of Atrial Fibrillation

Directory of Open Access Journals (Sweden)

Jacques Clementy

2007-01-01

Full Text Available Phrenic Nerve Injury (PNI has been well studied by cardiac surgeons. More recently it has been recognized as a potential complication of catheter ablation with a prevalence of 0.11 to 0.48 % after atrial fibrillation (AF ablation. This review will focus on PNI after AF ablation. Anatomical studies have shown a close relationship between the right phrenic nerve and it's proximity to the superior vena cava (SVC, and the antero-inferior part of the right superior pulmonary vein (RSPV. In addition, the proximity of the left phrenic nerve to the left atrial appendage has been well established. Independent of the type of ablation catheter (4mm, 8 mm, irrigated tip, balloon or energy source used (radiofrequency (RF, ultrasound, cryothermia, and laser; the risk of PNI exists during ablation at the critical areas listed above. Although up to thirty-one percent of patients with PNI after AF ablation remain asymptomatic, dyspnea remain the cardinal symptom and is present in all symptomatic patients. Despite the theoretical risk for significant adverse effect on functional status and quality of life, short-term outcomes from published studies appear favorable with 81% of patients with PNI having a complete recovery after 7 ± 7 months.Conclusion: Existing studies have described PNI as an uncommon but avoidable complication in patients undergoing pulmonary vein isolation for AF. Prior to ablation at the SVC, antero-inferior RSPV ostium or the left atrial appendage, pacing should be performed before energy delivery. If phrenic nerve capture is documented, energy delivery should be avoided at this site. Electrophysiologist's vigilance as well as pacing prior to ablation at high risk sites in close proximity to the phrenic nerve are the currently available tools to avoid the complication of PNI.

Paired motor cortex and cervical epidural electrical stimulation timed to converge in the spinal cord promotes lasting increases in motor responses.

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Mishra, Asht M; Pal, Ajay; Gupta, Disha; Carmel, Jason B

2017-11-15

Pairing motor cortex stimulation and spinal cord epidural stimulation produced large augmentation in motor cortex evoked potentials if they were timed to converge in the spinal cord. The modulation of cortical evoked potentials by spinal cord stimulation was largest when the spinal electrodes were placed over the dorsal root entry zone. Repeated pairing of motor cortex and spinal cord stimulation caused lasting increases in evoked potentials from both sites, but only if the time between the stimuli was optimal. Both immediate and lasting effects of paired stimulation are likely mediated by convergence of descending motor circuits and large diameter afferents onto common interneurons in the cervical spinal cord. Convergent activity in neural circuits can generate changes at their intersection. The rules of paired electrical stimulation are best understood for protocols that stimulate input circuits and their targets. We took a different approach by targeting the interaction of descending motor pathways and large diameter afferents in the spinal cord. We hypothesized that pairing stimulation of motor cortex and cervical spinal cord would strengthen motor responses through their convergence. We placed epidural electrodes over motor cortex and the dorsal cervical spinal cord in rats; motor evoked potentials (MEPs) were measured from biceps. MEPs evoked from motor cortex were robustly augmented with spinal epidural stimulation delivered at an intensity below the threshold for provoking an MEP. Augmentation was critically dependent on the timing and position of spinal stimulation. When the spinal stimulation was timed to coincide with the descending volley from motor cortex stimulation, MEPs were more than doubled. We then tested the effect of repeated pairing of motor cortex and spinal stimulation. Repetitive pairing caused strong augmentation of cortical MEPs and spinal excitability that lasted up to an hour after just 5 min of pairing. Additional physiology

Automatic Identification and Reconstruction of the Right Phrenic Nerve on Computed Tomography

OpenAIRE

Bamps, Kobe; Cuypers, Céline; Polmans, Pieter; Claesen, Luc; Koopman, Pieter

2016-01-01

An automatic computer algorithm was successfully constructed, enabling identification and reconstruction of the right phrenic nerve on high resolution coronary computed tomography scans. This could lead to a substantial reduction in the incidence of phrenic nerve paralysis during pulmonary vein isolation using ballon techniques.

Phrenic motoneuron expression of serotonergic and glutamatergic receptors following upper cervical spinal cord injury

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Mantilla, Carlos B.; Bailey, Jeffrey P.; Zhan, Wen-Zhi; Sieck, Gary C.

2012-01-01

Following cervical spinal cord injury at C2 (SH hemisection model) there is progressive recovery of phrenic activity. Neuroplasticity in the postsynaptic expression of neurotransmitter receptors may contribute to functional recovery. Phrenic motoneurons express multiple serotonergic (5-HTR) and glutamatergic (GluR) receptors, but the timing and possible role of these different neurotransmitter receptor subtypes in the neuroplasticity following SH are not clear. The current study was designed to test the hypothesis that there is an increased expression of serotonergic and glutamatergic neurotransmitter receptors within phrenic motoneurons after SH. In adult male rats, phrenic motoneurons were labeled retrogradely by intrapleural injection of Alexa 488-conjugated cholera toxin B. In thin (10 μm) frozen sections of the spinal cord, fluorescently-labeled phrenic motoneurons were visualized for laser capture microdissection (LCM). Using quantitative real-time RT-PCR in LCM samples, the time course of changes in 5-HTR and GluR mRNA expression was determined in phrenic motoneurons up to 21 days post-SH. Expression of 5-HTR subtypes 1b, 2a and 2c and GluR subtypes AMPA, NMDA, mGluR1 and mGluR5 was evident in phrenic motoneurons from control and SH rats. Phrenic motoneuron expression of 5-HTR2a increased ~8-fold (relative to control) at 14 days post-SH, whereas NMDA expression increased ~16-fold by 21-days post-SH. There were no other significant changes in receptor expression at any time post-SH. This is the first study to systematically document changes in motoneuron expression of multiple neurotransmitter receptors involved in regulation of motoneuron excitability. By providing information on the neuroplasticity of receptors expressed in a motoneuron pool that is inactivated by a higher-level spinal cord injury, appropriate pharmacological targets can be identified to alter motoneuron excitability. PMID:22227062

Phrenic nerve blocage with spinal anesthesia for laparoscopic Nissen fundoplication

Directory of Open Access Journals (Sweden)

Murat Dursun

2015-06-01

Full Text Available In this case, we describe a patient having laparoscopic Nissen fundoplication (LNF under spinal anesthesia with phrenic nerve blockade. It’s emphasized that in this type of operations, spinal anesthesia may be an alternative method rather the general anesthesia and the resulting shoulder pain in laparoscopic surgery performed under spinal anesthesia can be prevented by phrenic nerve blockade. J Clin Exp Invest 2015; 6 (2: 186-188

Phrenic pacing compared with mechanical ventilation

DEFF Research Database (Denmark)

Andersen, Morten Packert; Laub, Michael; Biering-Sørensen, Fin

2017-01-01

mechanical ventilator dependent tetraplegics met the inclusion criteria. Data were retrieved from medical records and a structured follow-up interview with seven individuals from each group. RESULTS: No significant differences were found when comparing age at injury, time since injury, length...... of hospitalization, incidence of pneumonia, number of pneumonia hospitalizations, number of tracheal suctions, speech quality and activities of daily living or quality of life. On the Short Form Health Survey (SF36) mental health summary the median for both users of phrenic nerve pacing and users of mechanical...... ventilation was one s.d. above the mean of a standard population. CONCLUSIONS: Nine people have had a phrenic nerve pacer implanted. They do not significantly differ from a group of home mechanical ventilator dependent tetraplegics on a number of performance measures, but both groups seem to have better...

Electromyographic monitoring for prevention of phrenic nerve palsy in second-generation cryoballoon procedures.

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Franceschi, Frédéric; Koutbi, Linda; Gitenay, Edouard; Hourdain, Jérome; Maille, Baptiste; Trévisan, Lory; Deharo, Jean-Claude

2015-04-01

Electromyography-guided phrenic nerve (PN) monitoring using a catheter positioned in a hepatic vein can aid in preventing phrenic nerve palsy (PNP) during cryoballoon ablation for atrial fibrillation. We wanted to evaluate the feasibility and efficacy of PN monitoring during procedures using second-generation cryoballoons. This study included 140 patients (43 women) in whom pulmonary vein isolation was performed using a second-generation cryoballoon. Electromyography-guided PN monitoring was performed by pacing the right PN at 60 per minute and recording diaphragmatic compound motor action potential (CMAP) via a quadripolar catheter positioned in a hepatic vein. If a 30% decrease in CMAP amplitude was observed, cryoapplication was discontinued with forced deflation to avoid a PNP. Monitoring was unfeasible in 8 of 140 patients (5.7%), PNP occurred in 1. Stable CMAP amplitudes were achieved before ablation in 132 of 140 patients (94.3%). In 18 of 132 patients (13.6%), a 30% decrease in CMAP amplitude occurred and cryoablation was discontinued. Each time, recovery of CMAP amplitude took <60 s. In 9 of 18 cases, a second cryoapplication in the same pulmonary vein was safely performed. We observed no PNP or complication related to electromyography-guided PN monitoring. Electromyography-guided PN monitoring using a catheter positioned in a hepatic vein seems feasible and effective to prevent PNP during cryoballoon ablation using second-generation cryoballoon. © 2015 American Heart Association, Inc.

Partial recovery of respiratory function and diaphragm reinnervation following unilateral vagus nerve to phrenic nerve anastomosis in rabbits.

Directory of Open Access Journals (Sweden)

Junxiang Wen

Full Text Available Respiratory dysfunction is the leading cause of mortality following upper cervical spinal cord injury (SCI. Reinnervation of the paralyzed diaphragm via an anastomosis between phrenic nerve and a donor nerve is a potential strategy to mitigate ventilatory deficits. In this study, anastomosis of vagus nerve (VN to phrenic nerve (PN in rabbits was performed to assess the potential capacity of the VN to compensate for lost PN inputs. At first, we compared spontaneous discharge pattern, nerve thickness and number of motor fibers between these nerves. The PN exhibited a highly rhythmic discharge while the VN exhibited a variable frequency discharge pattern. The rabbit VN had fewer motor axons (105.3±12.1 vs. 268.1±15.4. Nerve conduction and respiratory function were measured 20 weeks after left PN transection with or without left VN-PN anastomosis. Compared to rabbits subjected to unilateral phrenicotomy without VN-PN anastomosis, diaphragm muscle action potential (AP amplitude was improved by 292%, distal latency by 695%, peak inspiratory flow (PIF by 22.6%, peak expiratory flow (PRF by 36.4%, and tidal volume by 21.8% in the anastomosis group. However, PIF recovery was only 28.0%, PEF 28.2%, and tidal volume 31.2% of Control. Our results suggested that VN-PN anastomosis is a promising therapeutic strategy for partial restoration of diaphragm reinnervation, but further modification and improvements are necessary to realize the full potential of this technique.

Phrenic Nerve Palsy as Initial Presentation of Large Retrosternal Goitre.

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Hakeem, Arsheed Hussain; Hakeem, Imtiyaz Hussain; Wani, Fozia Jeelani

2016-12-01

Unilateral phrenic nerve palsy as initial presentation of the retrosternal goitre is extremely rare event. This is a case report of a 57-year-old woman with history of cough and breathlessness of 3 months duration, unaware of the thyroid mass. She had large cervico-mediastinal goiter and chest radiograph revealed raised left sided hemidiaphragm. Chest CT scan did not reveal any lung parenchymal or mediastinal pathology. The patient underwent a total thyroidectomy through a cervical approach. The final pathology was in favor of multinodular goitre. Even after 1 year of follow up, phrenic nerve palsy did not improve indicating permanent damage. Phrenic nerve palsy as initial presentation of the retrosternal goitre is unusual event. This case is reported not only because of the rare nature of presentation, but also to make clinicians aware of the entity so that early intervention may prevent attendant morbidity.

Convergence of pattern generator outputs on a common mechanism of diaphragm motor unit recruitment.

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Mantilla, Carlos B; Seven, Yasin B; Sieck, Gary C

2014-01-01

Motor units are the final element of neuromotor control. In manner analogous to the organization of neuromotor control in other skeletal muscles, diaphragm motor units comprise phrenic motoneurons located in the cervical spinal cord that innervate the diaphragm muscle, the main inspiratory muscle in mammals. Diaphragm motor units play a primary role in sustaining ventilation but are also active in other nonventilatory behaviors, including coughing, sneezing, vomiting, defecation, and parturition. Diaphragm muscle fibers comprise all fiber types. Thus, diaphragm motor units display substantial differences in contractile and fatigue properties, but importantly, properties of the motoneuron and muscle fibers within a motor unit are matched. As in other skeletal muscles, diaphragm motor units are recruited in order such that motor units that display greater fatigue resistance are recruited earlier and more often than more fatigable motor units. The properties of the motor unit population are critical determinants of the function of a skeletal muscle across the range of possible motor tasks. Accordingly, fatigue-resistant motor units are sufficient to generate the forces necessary for ventilatory behaviors, whereas more fatigable units are only activated during expulsive behaviors important for airway clearance. Neuromotor control of diaphragm motor units may reflect selective inputs from distinct pattern generators distributed according to the motor unit properties necessary to accomplish these different motor tasks. In contrast, widely distributed inputs to phrenic motoneurons from various pattern generators (e.g., for breathing, coughing, or vocalization) would dictate recruitment order based on intrinsic electrophysiological properties. © 2014 Elsevier B.V. All rights reserved.

CT anatomy of right phrenic nerve and pulmonary ligament

International Nuclear Information System (INIS)

Berkmen, Y.M.; Kazam, E.; Auh, Y.

1988-01-01

The relationship between the right phrenic nerve and the right pulmonary ligament was studied in eight cadavers and 100 computed tomographic (CT) examinations. The pulmonary ligament originates below the inferior pulmonary vein and is constantly posterior to the inferior vena cava. The lower end of the right phrenic nerve, on the other hand, descends over the lateral surface of the inferior vena cava, accompanied by the right cardiophrenic artery. The nerve spreads over the diaphragm within a thick parietal pleural fold, wrapped in a fatty tissue, and this should not be confused with pulmonary ligament on CT

Botulinum toxin type A in simple motor tics: short-term and long-term treatment-effects.

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Rath, Judith J G; Tavy, Dénes L J; Wertenbroek, Agnes A A C M; van Woerkom, Theodoor C A M; de Bruijn, Sebastiaan F T M

2010-08-01

To determine the short-term and long-term treatment-effects of botulinum toxin type A in simple motor tics, we analyzed 15 consecutive patients (18 tics) with simple motor tics that were treated every 3 months with injections of BTX-A. Efficacy (rated on a 4-level scale) and duration of effect of the first 2 and last 2 (if treated 5 times or more) treatments were recorded, as well as latency of response, changes of premonitory urges (PMUs) and possible side effects. Total number of treatments for each tic varied from 2 to 50 (mean 11, median 6). In 16 of 18 tics (89%) short-term efficacy was reported successful (good or moderate). Long-term efficacy was reported in 12 tics of which 11 showed similar or even increased beneficial effects. Premonitory urge (PMU) was reported in 8 patients (53%). PMU, if present, lessened or disappeared after treatment with BTX-A. A permanent remission of the treated tic was seen in 3 patients with a maximum follow-up of 10 years. BTX-A appears a safe and effective treatment for simple motor tics and retains its efficacy after long-term treatment. BTX may also induce permanent remission of the treated tics and effects of BTX are not restricted to merely motor behaviour.

CO2 sensitivity of the complexity of phrenic neurograms in the piglet during early maturation

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Akay, Metin

2005-06-01

In this paper, we investigate the influence of hypercapnia on the dynamics of the phrenic neurogram in the piglet in two different age groups: 3-7 days (n = 11) and 10-16 days (n = 9). The phrenic neurogram was recorded from 17 piglets (3-16 days old) during control (40% O2 with 3-5% end-tidal CO2), mild hypercapnia (40% O2 with 7% CO2) and severe hypercapnia (40% O2 with 15% CO2) and analyzed using the approximate entropy (ApEn) method. The mean values of the approximate entropy (complexity) of phrenic neurograms during the first 7 days of the postnatal age were 1.56 ± 0.1 (standard deviation) during normal breathing, 1.51 ± 0.1 during mild hypercapnia and 1.37 ± 0.08 during severe hypercapnia. These values for the 10-16 days age group were 1.51 ± 0.1 during control, 1.49 ± 0.11 during mild hypercapnia and 1.38 ± 0.05 during severe hypercapnia. The mean values of phrenic neurogram durations during the first 7 days of the postnatal age were 0.82 ± 0.03 (standard deviation) s during normal breathing, 0.85 ± 0.007 s during mild hypercapnia and 0.65 ± 0.05 s during severe hypercapnia. These values for the 10-16 days age group were 0.97 ± 0.09 s during control, 1.10 ± 0.05 during mild hypercapnia and 0.78 ± 0.05 s during severe hypercapnia. Our results show that the complexity values of the phrenic neurogram were significantly decreased when the CO2 concentration was shifted from control or mild to severe hypercapnia (p phrenic neurogram decreased when the concentration was shifted from control or mild to severe hypercapnia (p phrenic neurogram were observed between control and mild hypercapnia concentration. These results suggest that severe hypercapnia can be characterized with a significant decrease of the complexity values and durations of the phrenic neurogram during inspiration during early maturation.

In vitro assessment of induced phrenic nerve cryothermal injury.

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Goff, Ryan P; Bersie, Stephanie M; Iaizzo, Paul A

2014-10-01

Phrenic nerve injury, both left and right, is considered a significant complication of cryoballoon ablation for treatment of drug-refractory atrial fibrillation, and functional recovery of the phrenic nerve can take anywhere from hours to months. The purpose of this study was to focus on short periods of cooling to determine the minimal amount of cooling that may terminate nerve function related to cryo ablation. Left and/or right phrenic nerves were dissected from the pericardium and connective tissue of swine (n = 35 preparations). Nerves were placed in a recording chamber modified with a thermocouple array. This apparatus was placed in a digital water bath to maintain an internal chamber temperature of 37°C. Nerves were stimulated proximally with a 1-V, 0.1-ms square wave. Bipolar compound action potentials were recorded proximal and distal to the site of ablation both before and after ablation, then analyzed to determine changes in latency, amplitude, and duration. Temperatures were recorded at a rate of 5 Hz, and maximum cooling rates were calculated. Phrenic nerves were found to elicit compound action potentials upon stimulation for periods up to 4 hours minimum. Average conduction velocity was 56.7 ± 14.7 m/s preablation and 49.8 ± 16.6 m/s postablation (P = .17). Cooling to mild subzero temperatures ceased production of action potentials for >1 hour. Taking into account the data presented here, previous publications, and a conservative stance, during cryotherapy applications, cooling of the nerve to below 4°C should be avoided whenever possible. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Immediate balloon deflation for prevention of persistent phrenic nerve palsy during pulmonary vein isolation by balloon cryoablation.

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Ghosh, Justin; Sepahpour, Ali; Chan, Kim H; Singarayar, Suresh; McGuire, Mark A

2013-05-01

Persistent phrenic nerve palsy is the most frequent complication of cryoballoon ablation for atrial fibrillation and can be disabling. To describe a technique-immediate balloon deflation (IBD)-for the prevention of persistent phrenic nerve palsy, provide data for its use, and describe in vitro simulations performed to investigate the effect of IBD on the atrium and pulmonary vein. Cryoballoon procedures for atrial fibrillation were analyzed retrospectively (n = 130). IBD was performed in patients developing phrenic nerve dysfunction (n = 22). In vitro simulations were performed by using phantoms. No adverse events occurred, and all patients recovered normal phrenic nerve function before leaving the procedure room. No patient developed persistent phrenic nerve palsy. The mean cryoablation time to onset of phrenic nerve dysfunction was 144 ± 64 seconds. Transient phrenic nerve dysfunction was seen more frequently with the 23-mm balloon than with the 28-mm balloon (11 of 39 cases vs 11 of 81 cases; P = .036). Balloon rewarming was faster following IBD. The time to return to 0 and 20° C was shorter in the IBD group (6.7 vs 8.9 seconds; P = .007 and 16.7 vs 37.6 seconds; Pphrenic nerve palsy. Simulations suggest that IBD is unlikely to damage the atrium or pulmonary vein. Copyright © 2013 Heart Rhythm Society. All rights reserved.

Phrenic Arterial Injury Presenting as Delayed Hemothorax Complicating Simple Rib Fracture

OpenAIRE

Ahn, Hong Joon; Lee, Jun Wan; Kim, Kun Dong; You, In Sool

2016-01-01

Delayed hemothorax after blunt torso injury is rare, but might be associated with significant morbidity and mortality. We present a case of delayed hemothorax bleeding from phrenic artery injury in a 24-year-old woman. The patient suffered from multiple rib fractures on the right side, a right hemopneumothorax, thoracic vertebral injury and a pelvic bone fracture after a fall from a fourth floor window. Delayed hemothorax associated with phrenic artery bleeding, caused by a stab injury from a...

Long-Term Potentiation in the Motor Cortex

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Iriki, Atsushi; Pavlides, Constantine; Keller, Asaf; Asanuma, Hiroshi

1989-09-01

Long-term potentiation (LTP) is a model for learning and memory processes. Tetanic stimulation of the sensory cortex produces LTP in motor cortical neurons, whereas tetanization of the ventrolateral nucleus of the thalamus, which also projects to the motor cortex, does not. However, after simultaneous high-frequency stimulation of both the sensory cortex and the ventrolateral nucleus of the thalamus, LTP of thalamic input to motor cortical neurons is induced. This associative LTP occurs only in neurons in the superficial layers of the motor cortex that receive monosynaptic input from both the sensory cortex and the ventrolateral nucleus of the thalamus. Associative LTP in the motor cortex may constitute a basis for the retention of motor skills.

Effect of phrenic nerve palsy on early postoperative lung function after pneumonectomy: a prospective study.

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Kocher, Gregor J; Mauss, Karl; Carboni, Giovanni L; Hoksch, Beatrix; Kuster, Roland; Ott, Sebastian R; Schmid, Ralph A

2013-12-01

The issue of phrenic nerve preservation during pneumonectomy is still an unanswered question. So far, its direct effect on immediate postoperative pulmonary lung function has never been evaluated in a prospective trial. We conducted a prospective crossover study including 10 patients undergoing pneumonectomy for lung cancer between July 2011 and July 2012. After written informed consent, all consecutive patients who agreed to take part in the study and in whom preservation of the phrenic nerve during operation was possible, were included in the study. Upon completion of lung resection, a catheter was placed in the proximal paraphrenic tissue on the pericardial surface. After an initial phase of recovery of 5 days all patients underwent ultrasonographic assessment of diaphragmatic motion followed by lung function testing with and without induced phrenic nerve palsy. The controlled, temporary paralysis of the ipsilateral hemidiaphragm was achieved by local administration of lidocaine 1% at a rate of 3 mL/h (30 mg/h) via the above-mentioned catheter. Temporary phrenic nerve palsy was accomplished in all but 1 patient with suspected catheter dislocation. Spirometry showed a significant decrease in dynamic lung volumes (forced expiratory volume in 1 second and forced vital capacity; p phrenic nerve palsy causes a significant impairment of dynamic lung volumes during the early postoperative period after pneumonectomy. Therefore, in these already compromised patients, intraoperative phrenic nerve injury should be avoided whenever possible. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Visualization of the diaphragm muscle with ultrasound improves diagnostic accuracy of phrenic nerve conduction studies.

Science.gov (United States)

Johnson, Nicholas E; Utz, Michael; Patrick, Erica; Rheinwald, Nicole; Downs, Marlene; Dilek, Nuran; Dogra, Vikram; Logigian, Eric L

2014-05-01

Evaluation of phrenic neuropathy (PN) with phrenic nerve conduction studies (PNCS) is associated with false negatives. Visualization of diaphragmatic muscle twitch with diaphragm ultrasound (DUS) when performing PNCS may help to solve this problem. We performed bilateral, simultaneous DUS-PNCS in 10 healthy adults and 12 patients with PN. The amplitude of the diaphragm compound muscle action potential (CMAP) (on PNCS) and twitch (on DUS) was calculated. Control subjects had phrenic CMAP (on PCNS). In the 12 patients with PN, 12 phrenic neuropathies were detected. Three of these patients had either significant side-to-side asymmetry or absolute reduction in diaphragm movement that was not detected with PNCS. There were no cases in which the PNCS showed an abnormality but the DUS did not. The addition of DUS to PNCS enhances diagnostic accuracy in PN. Copyright © 2013 Wiley Periodicals, Inc.

Phrenic and hypoglossal nerve activity during respiratory response to hypoxia in 6-OHDA unilateral model of Parkinson's disease.

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Andrzejewski, Kryspin; Budzińska, Krystyna; Kaczyńska, Katarzyna

2017-07-01

Parkinson's disease (PD) patients apart from motor dysfunctions exhibit respiratory disturbances. Their mechanism is still unknown and requires investigation. Our research was designed to examine the activity of phrenic (PHR) and hypoglossal (HG) nerves activity during a hypoxic respiratory response in the 6-hydroxydopamine (6-OHDA) model of PD. Male adult Wistar rats were injected unilaterally with 6-OHDA (20μg) or the vehicle into the right medial forebrain bundle (MFB). Two weeks after the surgery the activity of the phrenic and hypoglossal nerve was registered in anesthetized, vagotomized, paralyzed, and mechanically ventilated rats under normoxic and hypoxic conditions. Lesion effectiveness was confirmed by the cylinder test, performed before the MFB injection and 14days after, before the respiratory experiment. 6-OHDA lesioned animals showed a significant increase in normoxic inspiratory time. Expiratory time and total time of the respiratory cycle were prolonged in PD rats after hypoxia. The amplitude of the PHR activity and its minute activity were increased in comparison to the sham group at recovery time and during 30s of hypoxia. The amplitude of the HG activity was increased in response to hypoxia in 6-OHDA lesioned animals. The degeneration of dopaminergic neurons decreased the pre-inspiratory/inspiratory ratio of the hypoglossal burst amplitude during and after hypoxia. Unilateral MFB lesion changed the activity of the phrenic and hypoglossal nerves. The altered pre-inspiratory hypoglossal nerve activity indicates modifications to the central mechanisms controlling the activity of the HG nerve and may explain respiratory disorders seen in PD, i.e. apnea. Copyright © 2017 Elsevier Inc. All rights reserved.

Phrenic nerve protection via packing of gauze into the pericardial space during ablation of cristal atrial tachycardia in a child.

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Takahashi, Kazuhiro; Fuchigami, Tai; Nabeshima, Taisuke; Sashinami, Arata; Nakayashiro, Mami

2016-03-01

The success of catheter ablation of focal atrial tachycardia is limited by possible collateral damage to the phrenic nerve. Protection of the phrenic nerve is required. Here we present a case of a 9-year-old girl having a history of an unsuccessful catheter ablation of a focal atrial tachycardia near the crista terminalis (because of proximity of the phrenic nerve) who underwent a successful ablation by means of a novel technique for phrenic nerve protection: packing of gauze into the pericardial space. This method is a viable approach for patients with a failed endocardial ablation due to the proximity of the phrenic nerve.

Fluoroscopy of spontaneous breathing is more sensitive than phrenic nerve stimulation for detection of right phrenic nerve injury during cryoballoon ablation of atrial fibrillation.

Science.gov (United States)

Linhart, Markus; Nielson, Annika; Andrié, René P; Mittmann-Braun, Erica L; Stöckigt, Florian; Kreuz, Jens; Nickenig, Georg; Schrickel, Jan W; Lickfett, Lars M

2014-08-01

Right phrenic nerve palsy (PNP) is a typical complication of cryoballoon ablation of the right-sided pulmonary veins (PVs). Phrenic nerve function can be monitored by palpating the abdomen during phrenic nerve pacing from the superior vena cava (SVC pacing) or by fluoroscopy of spontaneous breathing. We sought to compare the sensitivity of these 2 techniques during cryoballoon ablation for detection of PNP. A total of 133 patients undergoing cryoballoon ablation were monitored with both SVC pacing and fluoroscopy of spontaneous breathing during ablation of the right superior PV. PNP occurred in 27/133 patients (20.0%). Most patients (89%) had spontaneous recovery of phrenic nerve function at the end of the procedure or on the following day. Three patients were discharged with persistent PNP. All PNP were detected first by fluoroscopic observation of diaphragm movement during spontaneous breathing, while diaphragm could still be stimulated by SVC pacing. In patients with no recovery until discharge, PNP occurred at a significantly earlier time (86 ± 34 seconds vs. 296 ± 159 seconds, P < 0.001). No recovery occurred in 2/4 patients who were ablated with a 23 mm cryoballoon as opposed to 1/23 patients with a 28 mm cryoballoon (P = 0.049). Fluoroscopic assessment of diaphragm movement during spontaneous breathing is more sensitive for detection PNP as compared to SVC pacing. PNP as assessed by fluoroscopy is frequent (20.0%) and carries a high rate of recovery (89%) until discharge. Early onset of PNP and use of 23 mm cryoballoon are associated with PNP persisting beyond hospital discharge. © 2014 Wiley Periodicals, Inc.

Epicardial Ablation: Prevention of Phrenic Nerve Damage by Pericardial Injection of Saline and the Use of a Steerable Sheath

Directory of Open Access Journals (Sweden)

Kars Neven, MD

2014-03-01

Full Text Available Because of the close proximity of the phrenic nerve to the pericardium, phrenic nerve damage caused by epicardial ablation can easily occur. We report two cases of epicardial VT ablation where pericardial injection of saline, combined with the use of a steerable sheath, successfully prevents the phrenic nerve from being damaged.

Abnormal Origin and Course of the Accessory Phrenic Nerve: Case Report.

Science.gov (United States)

Paraskevas, George; Koutsouflianiotis, Konstantinos; Kitsoulis, Panagiotis; Spyridakis, Ioannis

In the current cadaveric study an unusual sizeable accessory phrenic nerve (APN) was encountered emerging from the trunk of the supraclavicular nerves and forming a triangular loop that was anastomosing with the phrenic nerve. That neural loop surrounded the superficial cervical artery which displayed a spiral course. The form of a triangular loop of APN involving the aforementioned artery and originating from the supraclavicular nerve to the best of our knowledge has not been documented previously in the literature. The variable morphological features of the APN along with its clinical applications are briefly discussed.

Functional recovery after cervical spinal cord injury: Role of neurotrophin and glutamatergic signaling in phrenic motoneurons.

Science.gov (United States)

Gill, Luther C; Gransee, Heather M; Sieck, Gary C; Mantilla, Carlos B

2016-06-01

Cervical spinal cord injury (SCI) interrupts descending neural drive to phrenic motoneurons causing diaphragm muscle (DIAm) paralysis. Recent studies using a well-established model of SCI, unilateral spinal hemisection of the C2 segment of the cervical spinal cord (SH), provide novel information regarding the molecular and cellular mechanisms of functional recovery after SCI. Over time post-SH, gradual recovery of rhythmic ipsilateral DIAm activity occurs. Recovery of ipsilateral DIAm electromyogram (EMG) activity following SH is enhanced by increasing brain-derived neurotrophic factor (BDNF) in the region of the phrenic motoneuron pool. Delivery of exogenous BDNF either via intrathecal infusion or via mesenchymal stem cells engineered to release BDNF similarly enhance recovery. Conversely, recovery after SH is blunted by quenching endogenous BDNF with the fusion-protein TrkB-Fc in the region of the phrenic motoneuron pool or by selective inhibition of TrkB kinase activity using a chemical-genetic approach in TrkB(F616A) mice. Furthermore, the importance of BDNF signaling via TrkB receptors at phrenic motoneurons is highlighted by the blunting of recovery by siRNA-mediated downregulation of TrkB receptor expression in phrenic motoneurons and by the enhancement of recovery evident following virally-induced increases in TrkB expression specifically in phrenic motoneurons. BDNF/TrkB signaling regulates synaptic plasticity in various neuronal systems, including glutamatergic pathways. Glutamatergic neurotransmission constitutes the main inspiratory-related, excitatory drive to motoneurons, and following SH, spontaneous neuroplasticity is associated with increased expression of ionotropic N-methyl-d-aspartate (NMDA) receptors in phrenic motoneurons. Evidence for the role of BDNF/TrkB and glutamatergic signaling in recovery of DIAm activity following cervical SCI is reviewed. Copyright © 2015 Elsevier B.V. All rights reserved.

Long lasting effects of chronic heavy cannabis abuse.

Science.gov (United States)

Nestoros, Joannis N; Vakonaki, Elena; Tzatzarakis, Manolis N; Alegakis, Athanasios; Skondras, Markos D; Tsatsakis, Aristidis M

2017-06-01

The purpose of this study was to evaluate the extent of short-term memory impairment and schizophrenia-like symptoms in heavy and systematic cannabis users and the association between the severity of abuse and the longevity of its persistent symptoms after refraining from such use. A complete psychiatric examination and a psychometric evaluation were performed in 48 solely cannabis users. Additionally, head hair samples were analyzed and the detected cannabinoids levels were correlated with the psychometric findings. A total of 33.3% (n = 16) of the total examined cannabis users were currently imprisoned. The years of abuse ranged from 1 to 35 years and the median daily dose was 5.84.4 gr and 4.84.0 gr for prisoners (n = 16) and non prisoners (n = 32), respectively. A total of 39.6% of the users experienced hallucinations (mostly auditory), 54.2% experienced delusions (mostly ideas of reference and persecution), 85.4% had organic brain dysfunction in a test addressing visual-motor functioning and visual perception skills, and all users (100%) were found to have organic brain dysfunction in a test of visual memory immediate recall. The cannabinoid metabolite levels in the hair samples were consistent with the reported history of substance abuse and total grams of consumption for the participants below 35 years old (p cannabis users seems to be associated with cannabinoid levels in hair. The continuation of persistent symptoms 3 months after the discontinuation of cannabis abuse, was a remarkable finding. We provide evidence that chronic and heavy cannabis abuse results in long-lasting brain dysfunction in all users and in long-lasting schizophrenia-like psychotic symptoms in more than half of all users. These findings suggest a reevaluation of the current classification of cannabis as a "soft narcotic" which erroneously, therefore, is typically considered harmless. (Am J Addict 2017;26:335-342). © 2017 American Academy of Addiction Psychiatry.

The phrenic nerve with accompanying vessels: a silent cause of cardiovascular border obliteration on chest radiography.

Science.gov (United States)

Farhana, Shiri; Ashizawa, Kazuto; Hayashi, Hideyuki; Ogihara, Yukihiro; Aso, Nobuya; Hayashi, Kuniaki; Uetani, Masataka

2015-12-01

Our aim was to clarify the frequency of cardiovascular border obliteration on frontal chest radiography and to prove that the phrenic nerve with accompanying vessels can be considered as a cause of obliteration of cardiovascular border on an otherwise normal chest radiography. Two radiologists reviewed chest radiographs and computed tomography (CT) images of 100 individuals. CT confirmed the absence of intrapulmonary or extrapulmonary abnormalities in all of them. We examined the frequency of cardiovascular border obliteration on frontal chest radiography and summarized the causes of obliteration as pericardial fat pad, phrenic nerve, intrafissure fat, pulmonary vessels, and others, comparing them with CT in each case. Cardiovascular border was obliterated on frontal chest radiography in 46 cases on the right and in 61 on the left. The phrenic nerve with accompanying vessels was found to be a cause of obliteration in 34 of 46 cases (74%) on the right and 29 of 61 (48%) cases on the left. The phrenic nerve was the most frequent cause of cardiovascular border obliteration on both sides. The phrenic nerve with accompanying vessels, forming a prominent fold of parietal pleura, can be attributed as a cause of cardiovascular border obliteration on frontal chest radiography.

Transcatheter lipiodol chemo-embolization of the inferior phrenic artery in hepatocellular carcinoma

International Nuclear Information System (INIS)

Chen Fanghong; Luo Zuyan; Yuan Jianhua; Yu Wenqiang; Cai Xuexiang; Hu Tingyang; Liu Zijiang

2002-01-01

Objective: To evaluate the efficacy of transcatheter lipiodol chemo-embolization therapy (TOCE) for HCC via inferior phrenic artery (IPA) and to analyse the location of the tumor feeding inferior phrenic artery. Methods: Twenty-five cases of HCC underwent the procedure of TOCE via the IPA, as well as the hepatic artery using Seldinger's method. The patterns of tumor growth included huge type in 12 cases, solitary nodular type in 8 cases and multiple nodular type in 5 cases. Hepatic artery and inferior phrenic artery chemo-embolization were performed in all cases. Results: Inferior phrenic artery originated from celiac trunk in 16 cases (64%); abdomen aorta around celiac trunk in 8(32%). The site-sort tumors supplied by IPA in right lobe (VII, VIII segment) were 23 cases and left lobe (IV segment) 2 cases. The cumulative survival rates of IPA chemo-embolization for hepatocellular carcinoma were 84%(1 year) and 68%(2 years). No severe complications occurred. Conclusions: TOCE of the IPA is a safe and effective method in the management of HCC supplied by IPA. When the tumor site is adjacent to diaphragm, hepatic ligaments or bare area, may arouse the blood supply by IPA, especially in no tumor staining or staining defect in hepatic artery angiography but tumor enhancement on CT, and increase of the level of serum α-fetoprotein

Long lasting decontamination foam

Science.gov (United States)

Demmer, Ricky L.; Peterman, Dean R.; Tripp, Julia L.; Cooper, David C.; Wright, Karen E.

2010-12-07

Compositions and methods for decontaminating surfaces are disclosed. More specifically, compositions and methods for decontamination using a composition capable of generating a long lasting foam are disclosed. Compositions may include a surfactant and gelatin and have a pH of less than about 6. Such compositions may further include affinity-shifting chemicals. Methods may include decontaminating a contaminated surface with a composition or a foam that may include a surfactant and gelatin and have a pH of less than about 6.

Spinal Metaplasticity in Respiratory Motor Control

Directory of Open Access Journals (Sweden)

Gordon S Mitchell

2015-02-01

Full Text Available A hallmark feature of the neural system controlling breathing is its ability to exhibit plasticity. Less appreciated is the ability to exhibit metaplasticity, a change in the capacity to express plasticity (ie. plastic plasticity. Recent advances in our understanding of cellular mechanisms giving rise to respiratory motor plasticity lay the groundwork for (ongoing investigations of metaplasticity. This detailed understanding of respiratory metaplasticity will be essential as we harness metaplasticity to restore breathing capacity in clinical disorders that compromise breathing, such as cervical spinal injury, motor neuron disease and other neuromuscular diseases. In this brief review, we discuss key examples of metaplasticity in respiratory motor control, and our current understanding of mechanisms giving rise to spinal plasticity and metaplasticity in phrenic motor output; particularly after pre-conditioning with intermittent hypoxia. Progress in this area has led to the realization that similar mechanisms are operative in other spinal motor networks, including those governing limb movement. Further, these mechanisms can be harnessed to restore respiratory and non-respiratory motor function after spinal injury.

CT evaluation of hepatocellular carcinomas supplied by right inferior phrenic arteries

International Nuclear Information System (INIS)

Wen Ming; Zhu Mingxia; Huang Yonghuo

2002-01-01

Objective: To evaluate the CT appearance of the hepatocellular carcinomas (HCC) supplied by the right inferior phrenic arteries (RIPA). Methods: A total of 195 consecutive cases of HCCs examined with helical CT and arteriography were studied. 15 proven HCCs cases were supplied by the RIPA. On arterial-phase CT images, the size of the RIPA, the left inferior phrenic arteries, and HCCs were measured, and the origin of RIPA and the location of HCCs were recorded. The CT findings in these 15 cases were correlated with arterio-graphic images. Results: CT showed RIPA on the right diaphragmatic crus as high attenuation in all patients. The origin of RIPA was demonstrated in 11 cases. The diameter of the RIPA (3.1 +- 1.1) mm was larger than that of the left inferior phrenic artery (1.3 +- 0.4) mm (P < 0.05). Conclusion: On CT images, if the RIPA asymmetrically dilates, and its diameter is larger than 2.5 mm, it is suggested that the HCC is supplied by the RIPA

Mechanical design of electric motors

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Tong, Wei

2014-01-01

Rapid increases in energy consumption and emphasis on environmental protection have posed challenges for the motor industry, as has the design and manufacture of highly efficient, reliable, cost-effective, energy-saving, quiet, precisely controlled, and long-lasting electric motors.Suitable for motor designers, engineers, and manufacturers, as well as maintenance personnel, undergraduate and graduate students, and academic researchers, Mechanical Design of Electric Motors provides in-depth knowledge of state-of-the-art design methods and developments of electric motors. From motor classificati

Long-lasting increase in axonal excitability after epidurally applied DC.

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Jankowska, Elzbieta; Kaczmarek, Dominik; Bolzoni, Francesco; Hammar, Ingela

2017-08-01

Effects of direct current (DC) on nerve fibers have primarily been investigated during or just after DC application. However, locally applied cathodal DC was recently demonstrated to increase the excitability of intraspinal preterminal axonal branches for >1 h. The aim of this study was therefore to investigate whether DC evokes a similarly long-lasting increase in the excitability of myelinated axons within the dorsal columns. The excitability of dorsal column fibers stimulated epidurally was monitored by recording compound action potentials in peripheral nerves in acute experiments in deeply anesthetized rats. The results show that 1 ) cathodal polarization (0.8-1.0 µA) results in a severalfold increase in the number of epidurally activated fibers and 2 ) the increase in the excitability appears within seconds, 3 ) lasts for >1 h, and 4 ) is activity independent, as it does not require fiber stimulation during the polarization. These features demonstrate an unexplored form of plasticity of myelinated fibers and indicate the conditions under which it develops. They also suggest that therapeutic effects of epidural stimulation may be significantly enhanced if it is combined with DC polarization. In particular, by using DC to increase the number of fibers activated by low-intensity epidural stimuli, the low clinical tolerance to higher stimulus intensities might be overcome. The activity independence of long-lasting DC effects would also allow the use of only brief periods of DC polarization preceding epidural stimulation to increase the effect. NEW & NOTEWORTHY The study indicates a new form of plasticity of myelinated fibers. The differences in time course of DC-evoked increases in the excitability of myelinated nerve fibers in the dorsal columns and in preterminal axonal branches suggest that distinct mechanisms are involved in them. The results show that combining epidural stimulation and transspinal DC polarization may dramatically improve their outcome and

Phrenic Nerve Conduction Study in the Early Stage of Guillain-Barre Syndrome as a Predictor of Respiratory Failure.

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Sen, Barun Kumar; Pandit, Alak

2018-01-01

Guillain-Barré syndrome (GBS) has unpredictable clinical course with severe complication of respiratory failure. To identify clinical profiles and electrophysiological study particularly non-invasive Phrenic nerve conduction study in patients of early GBS to predict respiratory failure. 64 adult (age≥18yrs) patients of early GBS (onset ≤ 14 days) during the study period from January 2014 to October 2015 were evaluated by clinical profiles of age, gender, antecedent infection, time to peak disability, single breath counts, cranial nerve involvement, autonomic dysfunction and non-invasive Phrenic nerve conduction study. Patients with predisposition factors of polyneuropathy like diabetes mellitus, hypothyroidism, vitamin deficiency, renal failure were excluded. Among 64 patients abnormal phrenic nerve conduction study was seen in 65.62% cases (42/64) and 45.23% (19/42) of them developed respiratory failure. Phrenic nerve sum latency, amplitude, duration and area were abnormal in those who developed respiratory failure and they had sum of phrenic nerve latency >28 msec, sum of CMAP amplitude 50 msec and sum of area phrenic nerve study developed respiratory failure. It was found that age, gender, preceding infection, autonomic involvement and types of GB syndrome had no influence on development of respiratory failure (p>0.05). Rapid disease progression to peak disability, more severe disease, shorter single breath counts and cranial nerve involvement were seen more often in patients with respiratory failure. Abnormal Phrenic nerve conduction study in the early Guillain-Barré syndrome might be of great value independently in predicting impending respiratory failure.

Phrenic Nerve Conduction Study in the Early Stage of Guillain–Barre Syndrome as a Predictor of Respiratory Failure

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Sen, Barun Kumar; Pandit, Alak

2018-01-01

Background: Guillain-Barré syndrome (GBS) has unpredictable clinical course with severe complication of respiratory failure. Objective: To identify clinical profiles and electrophysiological study particularly non-invasive Phrenic nerve conduction study in patients of early GBS to predict respiratory failure. Methods: 64 adult (age≥18yrs) patients of early GBS (onset ≤ 14 days) during the study period from January 2014 to October 2015 were evaluated by clinical profiles of age, gender, antecedent infection, time to peak disability, single breath counts, cranial nerve involvement, autonomic dysfunction and non-invasive Phrenic nerve conduction study. Patients with predisposition factors of polyneuropathy like diabetes mellitus, hypothyroidism, vitamin deficiency, renal failure were excluded. Results: Among 64 patients abnormal phrenic nerve conduction study was seen in 65.62% cases (42/64) and 45.23% (19/42) of them developed respiratory failure. Phrenic nerve sum latency, amplitude, duration and area were abnormal in those who developed respiratory failure and they had sum of phrenic nerve latency >28 msec, sum of CMAP amplitude 50 msec and sum of area phrenic nerve study developed respiratory failure. It was found that age, gender, preceding infection, autonomic involvement and types of GB syndrome had no influence on development of respiratory failure (p>0.05). Rapid disease progression to peak disability, more severe disease, shorter single breath counts and cranial nerve involvement were seen more often in patients with respiratory failure. Conclusion: Abnormal Phrenic nerve conduction study in the early Guillain-Barré syndrome might be of great value independently in predicting impending respiratory failure. PMID:29720799

Acute diaphragmatic paralysis caused by chest-tube trauma to phrenic nerve

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Nahum, E.; Ben-Ari, J.; Schonfeld, T. [Pediatric Intensive Care Unit, Schneider Children' s Medical Center of Israel, Petah Tiqva (Israel); Horev, G. [Dept. of Diagnostic Radiology, Schneider Children' s Medical Center of Israel, Petah Tiqva (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel)

2001-06-01

A 3{sup 1}/{sub 2}-year-old child developed unilateral diaphragmatic paralysis after chest drain insertion. Plain chest X-ray demonstrated paravertebral positioning of the chest-tube tip, and magnetic resonance imaging revealed hematomas in the region of the chest-tube tip and the phrenic nerve fibers. The trauma to the phrenic nerve was apparently secondary to malposition of the chest tube. This is a rare complication and has been reported mainly in neonates. Radiologists should notify the treating physicians that the correct position of a chest drain tip is at least 2 cm distant from the vertebrae. (orig.)

Abnormal Origin and Course of the Accessory Phrenic Nerve: Case Report

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George Paraskevas

2016-08-01

Full Text Available In the current cadaveric study an unusual sizeable accessory phrenic nerve (APN was encountered emerging from the trunk of the supraclavicular nerves and forming a triangular loop that was anastomosing with the phrenic nerve. That neural loop surrounded the superficial cervical artery which displayed a spiral course. The form of a triangular loop of APN involving the aforementioned artery and originating from the supraclavicular nerve to the best of our knowledge has not been documented previously in the literature. The variable morphological features of the APN along with its clinical applications are briefly discussed.

Acute diaphragmatic paralysis caused by chest-tube trauma to phrenic nerve

International Nuclear Information System (INIS)

Nahum, E.; Ben-Ari, J.; Schonfeld, T.; Horev, G.

2001-01-01

A 3 1 / 2 -year-old child developed unilateral diaphragmatic paralysis after chest drain insertion. Plain chest X-ray demonstrated paravertebral positioning of the chest-tube tip, and magnetic resonance imaging revealed hematomas in the region of the chest-tube tip and the phrenic nerve fibers. The trauma to the phrenic nerve was apparently secondary to malposition of the chest tube. This is a rare complication and has been reported mainly in neonates. Radiologists should notify the treating physicians that the correct position of a chest drain tip is at least 2 cm distant from the vertebrae. (orig.)

Usefulness of phrenic latency and forced vital capacity in patients with ALS with latent respiratory dysfunction.

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Kwon, Soonwook; Min, Ju-Hong; Cho, Hye-Jin; Joo, Byung-Euk; Cho, Eun Bin; Seok, Jin Myoung; Kim, Min-Ji; Kim, Byoung Joon

2015-07-01

The pulmonary function test (PFT) is a non-invasive and easily available technique to assess respiratory function in patients with amyotrophic lateral sclerosis (ALS); however, patients with dyspnea sometimes show normal PFT findings. Herein, we investigated whether phrenic nerve conduction study (NCS) and PFT are useful to evaluate respiratory function of patients with ALS with normal value ranges in the PFT. We prospectively enrolled 34 patients with definite or probable ALS, who showed FVC (%) ⩾80 of predicted and 78 healthy subjects. PFT and phrenic NCS were performed with the measurement of forced vital capacity (FVC, %), forced expiratory volumes in 1s (FEV1, %), FEV1/FCV ratio (%), and phrenic compound muscle action potential amplitude, and latency. Compared to healthy controls, ALS patients showed delayed phrenic nerve latency and the decrease of FVC (%) (p=0.006 and pphrenic latency (AUC=0.7655) and FVC (%) (AUC=0.8239) discriminated ALS patients from healthy subjects. We demonstrated that ALS patients had early respiratory dysfunction, despite normal PFT findings. Phrenic latency and FVC (%) can be helpful to discriminate ALS patients with latent respiratory dysfunction from healthy subjects. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Do motor neurons contain functional prejunctional cholinoceptors?

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Bierkamper, C.G.; Aizenman, E.; Millington, W.R.

1986-01-01

This paper focuses on negative feedback by nicotinic cholinoceptors (nAChR) on motor nerve terminals. The authors attempt to prove the existence of the receptor, determine its pharmacologic characteristics, and demonstrate that it can alter ACh release. Acetylcholine release from the vascular perfused rat phrenic nerve-hemidiaphragm prepareation is assessed by three methods; measurement of force of contraction; direct assay of released ACh by radioenzymatic assay; and intracellular recording from the endplate region of the myofiber

MRI Reconstructions of Human Phrenic Nerve Anatomy and Computational Modeling of Cryoballoon Ablative Therapy.

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Goff, Ryan P; Spencer, Julianne H; Iaizzo, Paul A

2016-04-01

The primary goal of this computational modeling study was to better quantify the relative distance of the phrenic nerves to areas where cryoballoon ablations may be applied within the left atria. Phrenic nerve injury can be a significant complication of applied ablative therapies for treatment of drug refractory atrial fibrillation. To date, published reports suggest that such injuries may occur more frequently in cryoballoon ablations than in radiofrequency therapies. Ten human heart-lung blocs were prepared in an end-diastolic state, scanned with MRI, and analyzed using Mimics software as a means to make anatomical measurements. Next, generated computer models of ArticFront cryoballoons (23, 28 mm) were mated with reconstructed pulmonary vein ostias to determine relative distances between the phrenic nerves and projected balloon placements, simulating pulmonary vein isolation. The effects of deep seating balloons were also investigated. Interestingly, the relative anatomical differences in placement of 23 and 28 mm cryoballoons were quite small, e.g., the determined difference between mid spline distance to the phrenic nerves between the two cryoballoon sizes was only 1.7 ± 1.2 mm. Furthermore, the right phrenic nerves were commonly closer to the pulmonary veins than the left, and surprisingly tips of balloons were further from the nerves, yet balloon size choice did not significantly alter calculated distance to the nerves. Such computational modeling is considered as a useful tool for both clinicians and device designers to better understand these associated anatomies that, in turn, may lead to optimization of therapeutic treatments.

A ferromagnetic surgical system reduces phrenic nerve injury in redo congenital cardiac surgery.

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Shinkawa, Takeshi; Holloway, Jessica; Tang, Xinyu; Gossett, Jeffrey M; Imamura, Michiaki

2017-05-01

A ferromagnetic surgical system (FMwand®) is a new type of dissection device expected to reduce the risk of adjacent tissue damage. We reviewed 426 congenital cardiac operations with cardiopulmonary bypass through redo sternotomy to assess if this device prevented phrenic nerve injury. The ferromagnetic surgical system was used in 203 operations (47.7%) with regular electrocautery and scissors. The preoperative and operative details were similar between the operations with or without the ferromagnetic surgical system. The incidence of phrenic nerve injury was significantly lower with the ferromagnetic surgical system (0% vs 2.7%, P = 0.031). A logistic regression model showed that the use of the ferromagnetic surgical system was significantly associated with reduced odds of phrenic nerve injury (P < 0.001). © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Successful Reinnervation of the Diaphragm After Intercostal to Phrenic Nerve Neurotization in Patients With High Spinal Cord Injury.

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Nandra, Kulvir S; Harari, Martin; Price, Thea P; Greaney, Patrick J; Weinstein, Michael S

2017-08-01

Our objective in this study was to extend diaphragmatic pacing therapy to include paraplegic patients with high cervical spinal cord injuries between C3 and C5. Diaphragmatic pacing has been used in patients experiencing ventilator-dependent respiratory failure due to spinal cord injury as a means to reduce or eliminate the need for mechanical ventilation. However, this technique relies on intact phrenic nerve function. Recently, phrenic nerve reconstruction with intercostal nerve grafting has expanded the indications for diaphragmatic pacing. Our study aimed to evaluate early outcomes and efficacy of intercostal nerve transfer in diaphragmatic pacing. Four ventilator-dependent patients with high cervical spinal cord injuries were selected for this study. Each patient demonstrated absence of phrenic nerve function via external neck stimulation and laparoscopic diaphragm mapping. Each patient underwent intercostal to phrenic nerve grafting with implantation of a phrenic nerve pacer. The patients were followed, and ventilator dependence was reassessed at 1 year postoperatively. Our primary outcome was measured by the amount of time our patients tolerated off the ventilator per day. We found that all 4 patients have tolerated paced breathing independent of mechanical ventilation, with 1 patient achieving 24 hours of tracheostomy collar. From this study, intercostal to phrenic nerve transfer seems to be a promising approach in reducing or eliminating ventilator support in patients with C3 to C5 high spinal cord injury.

Imaging before cryoablation of atrial fibrillation: is phrenic nerve palsy predictable?

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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.

Short-term and long-term plasticity interaction in human primary motor cortex.

Science.gov (United States)

Iezzi, Ennio; Suppa, Antonio; Conte, Antonella; Li Voti, Pietro; Bologna, Matteo; Berardelli, Alfredo

2011-05-01

Repetitive transcranial magnetic stimulation (rTMS) over primary motor cortex (M1) elicits changes in motor evoked potential (MEP) size thought to reflect short- and long-term forms of synaptic plasticity, resembling short-term potentiation (STP) and long-term potentiation/depression (LTP/LTD) observed in animal experiments. We designed this study in healthy humans to investigate whether STP as elicited by 5-Hz rTMS interferes with LTP/LTD-like plasticity induced by intermittent and continuous theta-burst stimulation (iTBS and cTBS). The effects induced by 5-Hz rTMS and iTBS/cTBS were indexed as changes in MEP size. We separately evaluated changes induced by 5-Hz rTMS, iTBS and cTBS applied alone and those induced by iTBS and cTBS delivered after priming 5-Hz rTMS. Interactions between 5-Hz rTMS and iTBS/cTBS were investigated under several experimental conditions by delivering 5-Hz rTMS at suprathreshold and subthreshold intensity, allowing 1 and 5 min intervals to elapse between 5-Hz rTMS and TBS, and delivering one and ten 5-Hz rTMS trains. We also investigated whether 5-Hz rTMS induces changes in intracortical excitability tested with paired-pulse transcranial magnetic stimulation. When given alone, 5-Hz rTMS induced short-lasting and iTBS/cTBS induced long-lasting changes in MEP amplitudes. When M1 was primed with 10 suprathreshold 5-Hz rTMS trains at 1 min before iTBS or cTBS, the iTBS/cTBS-induced after-effects disappeared. The 5-Hz rTMS left intracortical excitability unchanged. We suggest that STP elicited by suprathreshold 5-Hz rTMS abolishes iTBS/cTBS-induced LTP/LTD-like plasticity through non-homeostatic metaplasticity mechanisms. Our study provides new information on interactions between short-term and long-term rTMS-induced plasticity in human M1. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Intermittent Hypoxia and Stem Cell Implants Preserve Breathing Capacity in a Rodent Model of Amyotrophic Lateral Sclerosis

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Nichols, Nicole L.; Gowing, Genevieve; Satriotomo, Irawan; Nashold, Lisa J.; Dale, Erica A.; Suzuki, Masatoshi; Avalos, Pablo; Mulcrone, Patrick L.; McHugh, Jacalyn

2013-01-01

Rationale: Amyotrophic lateral sclerosis (ALS) is a devastating motor neuron disease causing paralysis and death from respiratory failure. Strategies to preserve and/or restore respiratory function are critical for successful treatment. Although breathing capacity is maintained until late in disease progression in rodent models of familial ALS (SOD1G93A rats and mice), reduced numbers of phrenic motor neurons and decreased phrenic nerve activity are observed. Decreased phrenic motor output suggests imminent respiratory failure. Objectives: To preserve or restore phrenic nerve activity in SOD1G93A rats at disease end stage. Methods: SOD1G93A rats were injected with human neural progenitor cells (hNPCs) bracketing the phrenic motor nucleus before disease onset, or exposed to acute intermittent hypoxia (AIH) at disease end stage. Measurements and Main Results: The capacity to generate phrenic motor output in anesthetized rats at disease end stage was: (1) transiently restored by a single presentation of AIH; and (2) preserved ipsilateral to hNPC transplants made before disease onset. hNPC transplants improved ipsilateral phrenic motor neuron survival. Conclusions: AIH-induced respiratory plasticity and stem cell therapy have complementary translational potential to treat breathing deficits in patients with ALS. PMID:23220913

Phrenic Nerve Palsy Secondary to Parsonage-Turner Syndrome: A Diagnosis Commonly Overlooked.

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McEnery, Tom; Walsh, Ronan; Burke, Conor; McGowan, Aisling; Faul, John; Cormican, Liam

2017-04-01

Neuralgic Amyotrophy (NA) or Parsonage-Turner syndrome is an idiopathic neuropathy commonly affecting the brachial plexus. Associated phrenic nerve involvement, though recognised, is thought to be very rare. We present a case series of four patients (all male, mean age 53) presenting with dyspnoea preceded by severe self-limiting upper limb and shoulder pain, with an elevated hemi-diaphragm on clinical examination and chest X-ray. Neurological examination of the upper limb at the time of presentation was normal. Diaphragmatic fluoroscopy confirmed unilateral diaphragmatic paralysis. Pulmonary function testing demonstrated characteristic reduction in forced vital capacity between supine and sitting position (mean 50%, range 42-65% predicted, mean change 23%, range 22-46%), reduced maximal inspiratory pressures (mean 61%, range 43-86% predicted), reduced sniff nasal inspiratory pressure (mean 88.25, range 66-109 cm H 2 O) and preserved maximal expiratory pressure (mean 107%, range 83-130% predicted). Phrenic nerve conduction studies confirmed phrenic nerve palsy. All patients were managed conservatively. Follow-up ranged from 6 months to 3 years. Symptoms and lung function variables normalised in three patients and improved significantly in the fourth. The classic history of severe ipsilateral shoulder and upper limb neuromuscular pain should be elicited and thus NA considered in the differential for a unilateral diaphragmatic paralysis, even in the absence of neurological signs. Parsonage-Turner syndrome is likely to represent a significantly under-diagnosed aetiology of phrenic nerve palsy. Conservative management as opposed to surgical intervention is advocated as most patients demonstrate gradual resolution over time in this case series.

Phrenic nerve stimulation for the treatment of central sleep apnea.

Science.gov (United States)

Abraham, William T; Jagielski, Dariusz; Oldenburg, Olaf; Augostini, Ralph; Krueger, Steven; Kolodziej, Adam; Gutleben, Klaus-Jürgen; Khayat, Rami; Merliss, Andrew; Harsch, Manya R; Holcomb, Richard G; Javaheri, Shahrokh; Ponikowski, Piotr

2015-05-01

The aim of this study was to evaluate chronic, transvenous, unilateral phrenic nerve stimulation to treat central sleep apnea (CSA) in a prospective, multicenter, nonrandomized study. CSA occurs predominantly in patients with heart failure and increases the risk for morbidity and mortality. Established therapies for CSA are lacking, and those available are limited by poor patient adherence. Fifty-seven patients with CSA underwent baseline polysomnography followed by transvenous phrenic nerve stimulation system implantation and follow-up. Feasibility was assessed by implantation success rate and therapy delivery. Safety was evaluated by monitoring of device- and procedure-related adverse events. Efficacy was evaluated by changes in the apnea-hypopnea index at 3 months. Quality of life at 6 months was evaluated using a sleepiness questionnaire, patient global assessment, and, in patients with heart failure at baseline, the Minnesota Living With Heart Failure Questionnaire. The study met its primary end point, demonstrating a 55% reduction in apnea-hypopnea index from baseline to 3 months (49.5 ± 14.6 episodes/h vs. 22.4 ± 13.6 episodes/h of sleep; p phrenic nerve stimulation appears safe and effective for treating CSA. These findings should be confirmed in a prospective, randomized, controlled trial. (Chronic Evaluation of Respicardia Therapy; NCT01124370). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Effects of ischemic phrenic nerve root ganglion injury on respiratory disturbances in subarachnoid hemorrhage: an experimental study.

Science.gov (United States)

Ulvi, Hızır; Demir, Recep; Aygül, Recep; Kotan, Dilcan; Calik, Muhammet; Aydin, Mehmet Dumlu

2013-12-30

Phrenic nerves have important roles on the management of respiration rhythm. Diaphragm paralysis is possible in phrenic nerve roots ischemia in subarachnoid hemorrhage (SAH). We examined whether there is a relationship between phrenic nerve root ischemia and respiratory disturbances in SAH. This study was conducted on 5 healthy control and 14 rabbits with experimentally induced SAH by injecting autologous blood into their cisterna magna. Animals were followed up via monitors for detecting the heart and respiration rhythms for 20 days and then decapitaed by humanely. Normal and degenerated neuron densities of phrenic nerve root at the level of C4 dorsal root ganglia (C4DRG) were estimated by Stereological methods. Between the mean numerical density of degenerated neurons of C4DRG and respiratory rate/minute of groups were compared statistically. Phrenic nerve roots, artery and diaphragm muscles degeneration was detected in respiratory arrest developed animals. The mean neuronal density of C4DRG was 13272 ±1201/mm3 with a mean respiration rate of 23 ±4/min in the control group. The mean degenerated neuron density was 2.240 ±450/mm(3) and respiration rhythm was 31 ±6/min in survivors. But, the mean degenerated neuron density was 5850 ±650/mm(3) and mean respiration rhythm was 34 ±7/min in respiratory arrest developed animals (n = 7). A linear relationship was noticed between the degenerated neuron density of C4DRG and respiraton rate (r = -0.758; p Phrenic nerve root ischemia may be an important factor in respiration rhythms deteriorations in SAH which has not been mentioned in the literature.

Diaphragmatic paralysis evaluated by phrenic nerve stimulation during fluoroscopy or real-time ultrasound

Energy Technology Data Exchange (ETDEWEB)

McCauley, R.G.K.; Labib, K.B.

1984-10-01

Stimulation of the phrenic nerve by supplying an electrical impulse to the neck during fluoroscopy or real-time ultrasound (sonoscopy) of the diaphragm allows more precise functional evaluation than fluoroscopy and/or sonoscopy alone. This is especially true of patients who are unable to cooperate because the are on a ventilator, unconscious, or very young. The authors cite cases in which diaphragmatic paralysis was diagnosed by conventional methods but stimulation of the phrenic nerve demonstrated good diaphragmatic motion, leading to a change in prognosis in some cases and a change in therapy in others.

Diaphragmatic paralysis evaluated by phrenic nerve stimulation during fluoroscopy or real-time ultrasound

International Nuclear Information System (INIS)

McCauley, R.G.K.; Labib, K.B.

1984-01-01

Stimulation of the phrenic nerve by supplying an electrical impulse to the neck during fluoroscopy or real-time ultrasound (sonoscopy) of the diaphragm allows more precise functional evaluation than fluoroscopy and/or sonoscopy alone. This is especially true of patients who are unable to cooperate because the are on a ventilator, unconscious, or very young. The authors cite cases in which diaphragmatic paralysis was diagnosed by conventional methods but stimulation of the phrenic nerve demonstrated good diaphragmatic motion, leading to a change in prognosis in some cases and a change in therapy in others

Femoral venous pressure waveform as indicator of phrenic nerve injury in the setting of second-generation cryoballoon ablation.

Science.gov (United States)

Mugnai, Giacomo; de Asmundis, Carlo; Ströker, Erwin; Hünük, Burak; Moran, Darragh; Ruggiero, Diego; De Regibus, Valentina; Coutino-Moreno, Hugo Enrique; Takarada, Ken; Choudhury, Rajin; Poelaert, Jan; Verborgh, Christian; Brugada, Pedro; Chierchia, Gian-Battista

2017-07-01

Femoral venous pressure waveform (VPW) analysis has been recently described as a novel method to assess phrenic nerve function during atrial fibrillation ablation procedures by means of the cryoballoon technique. In this study, we sought to evaluate the feasibility and effectiveness of this technique, with respect to the incidence of phrenic nerve injury (PNI), in comparison with the traditional abdominal palpation technique alone. Consecutive patients undergoing second-generation cryoballoon ablation (CB-A) from June 2014 to June 2015 were retrospectively analyzed. Diagnosis of PNI was made if any reduced motility or paralysis of the hemidiaphragm was detected on fluoroscopy. During the study period, a total of 350 consecutive patients (man 67%, age 57.2 ± 12.9 years) were enrolled (200 using traditional phrenic nerve assessment and 150 using VPW monitoring). The incidence of PNI in the overall population was 8.0% (28/350); of these, eight were impending PNI (2.3%), 14 transient (4.0%), and six persistent (1.7%). Patients having undergone CB-A with traditional assessment experienced 18 phrenic nerve palsies (9.0%) vs two in 'VPW monitoring' group (1.3%; P = 0.002). Specifically, the former presented 12 transient (6.0%) and six persistent (3.0%) phrenic nerve palsies, and the latter exhibited two transient (1.3%; P = 0.03) and no persistent (0%; P = 0.04) phrenic nerve palsies. In conclusion, this novel method assessing the VPW for predicting PNI is inexpensive, easily available, with reproducible measurements, and appears to be more effective than traditional assessment methods.

Effects of cartap on isolated mouse phrenic nerve diaphragm and its related mechanism.

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Liao, J W; Kang, J J; Liu, S H; Jeng, C R; Cheng, Y W; Hu, C M; Tsai, S F; Wang, S C; Pang, V F

2000-06-01

Cartap, a nereistoxin analogue pesticide, is reported to have no irritation to eyes in rabbits. However, we have demonstrated recently that cartap could actually cause acute death in rabbits via ocular exposure. Our preliminary study with isolated mouse phrenic nerve diaphragms has shown that instead of neuromuscular blockade, cartap caused muscular contracture. The objective of the study was to examine the effect of cartap on the neuromuscular junction in more detail and to investigate its possible underlying mechanism with isolated mouse phrenic nerve diaphragms and sarcoplasmic reticulum (SR) vesicles. Cartap or nereistoxin at various concentrations was added in the organ bath with isolated mouse phrenic nerve diaphragm and both nerve- and muscle-evoked twitches were recorded. Instead of blocking the neuromuscular transmission as nereistoxin did, cartap caused contracture in stimulated or quiescent isolated mouse phrenic nerve diaphragm. Both the cartap-induced muscular contracture force and the time interval to initiate the contracture were dose-dependent. The contracture induced by cartap was not affected by the pretreatment of the diaphragm with the acetylcholine receptor blocker alpha-bungarotoxin; the Na(+) channel blocker tetrodotoxin; or various Ca(2+) channel blockers, NiCl(2), verapamil, and nifedipine. On the contrary, the contracture was significantly inhibited when the diaphragm was pretreated with ryanodine or EGTA containing Ca(2+)-free Krebs solution or in combination. This suggested that both internal and extracellular Ca(2+) might participate in cartap-induced skeletal muscle contracture. Moreover, cartap inhibited the [(3)H]-ryanodine binding to the Ca(2+) release channel of SR in a dose-dependent manner. Additionally, cartap could induce a significant reduction in Ca(2+)-ATPase activity of SR vesicles at a relatively high dose. The results suggested that cartap might cause the influx of extracellular Ca(2+) and the release of internal Ca(2

Long-Lasting Sound-Evoked Afterdischarge in the Auditory Midbrain.

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Ono, Munenori; Bishop, Deborah C; Oliver, Douglas L

2016-02-12

Different forms of plasticity are known to play a critical role in the processing of information about sound. Here, we report a novel neural plastic response in the inferior colliculus, an auditory center in the midbrain of the auditory pathway. A vigorous, long-lasting sound-evoked afterdischarge (LSA) is seen in a subpopulation of both glutamatergic and GABAergic neurons in the central nucleus of the inferior colliculus of normal hearing mice. These neurons were identified with single unit recordings and optogenetics in vivo. The LSA can continue for up to several minutes after the offset of the sound. LSA is induced by long-lasting, or repetitive short-duration, innocuous sounds. Neurons with LSA showed less adaptation than the neurons without LSA. The mechanisms that cause this neural behavior are unknown but may be a function of intrinsic mechanisms or the microcircuitry of the inferior colliculus. Since LSA produces long-lasting firing in the absence of sound, it may be relevant to temporary or chronic tinnitus or to some other aftereffect of long-duration sound.

Active Motor Training Has Long-term Effects on Infants’ Object Exploration

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Wiesen, Sarah E.; Watkins, Rachel M.; Needham, Amy Work

2016-01-01

Long-term changes in infants’ behavior as a result of active motor training were studied. Thirty-two infants completed three visits to the laboratory. At the first visit, infants were 3 months old and completed an object exploration assessment. Then the experimenter demonstrated the motor training procedures appropriate for the infant’s experimental condition, and parents took home custom infant mittens (either sticky or non-sticky) and a bag of lightweight toys to practice with their infants. Over the course of the following 2 weeks, infants participated in 10 sessions of either active (sticky) or passive (non-sticky) mittens training at home with their parents. Infants who participated in active mittens training wore mittens with the palms covered in Velcro, allowing them to pick up and move around small toys. Infants who participated in passive mittens training wore non-sticky mittens, and their parents moved the toys through their visual fields on their behalf. After completing the training, infants returned to the lab for the second visit. At visit two, infants participated in another object exploration assessment as well as a reaching assessment. Parents returned the training materials to the lab at the second visit, and were told not to continue any specific training regimen from this point forward. Two months later, when infants were about 5.5 months of age, they returned to the lab for a third visit. At the third visit, infants completed the same two assessments as during the second visit. The results of this study indicate that infants who participated in active motor training engaged in more sophisticated object exploration when compared to infants who received passive training. These findings are consistent with others in the literature showing that active motor training at 3 months of age facilitates the processes of object exploration and engagement. The current results and others reveal that the effects of early experience can last long after

Phrenic Nerve Palsy and Regional Anesthesia for Shoulder Surgery: Anatomical, Physiologic, and Clinical Considerations.

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El-Boghdadly, Kariem; Chin, Ki Jinn; Chan, Vincent W S

2017-07-01

Regional anesthesia has an established role in providing perioperative analgesia for shoulder surgery. However, phrenic nerve palsy is a significant complication that potentially limits the use of regional anesthesia, particularly in high-risk patients. The authors describe the anatomical, physiologic, and clinical principles relevant to phrenic nerve palsy in this context. They also present a comprehensive review of the strategies for reducing phrenic nerve palsy and its clinical impact while ensuring adequate analgesia for shoulder surgery. The most important of these include limiting local anesthetic dose and injection volume and performing the injection further away from the C5-C6 nerve roots. Targeting peripheral nerves supplying the shoulder, such as the suprascapular and axillary nerves, may be an effective alternative to brachial plexus blockade in selected patients. The optimal regional anesthetic approach in shoulder surgery should be tailored to individual patients based on comorbidities, type of surgery, and the principles described in this article.

Common and separate origins of the left and right inferior phrenic artery with a review of the literature.

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Terayama, H; Yi, S-Q; Tanaka, O; Kanazawa, T; Suyama, K; Kosemura, N; Tetsu, S; Yamazaki, H; Sakamoto, R; Kawakami, S; Suzuki, T; Sakabe, K

2017-01-01

In a 94-year-old male cadaver, upon which routine dissection was being conducted, a rare variation was found in the gastrophrenic trunk (GPT), the common trunk of the left gastric artery (LGA), right inferior phrenic artery (RIPA), and left inferior phrenic artery (LIPA); the GPT arises from the abdominal aorta. A hepatosplenic trunk accompanied the variation. In this variation, the RIPA first branched from the GPT and then to the LIPA and LGA. Variations in the common trunk of the LIPA and RIPA in the GPT are common, but to our knowledge, a variation (separate inferior phrenic artery in the GPT) similar to our findings has not been previously reported. We discuss the incidence and developmental and clinical significance of this variation with a detailed review of the literature. Knowledge of such a case has important clinical significance for invasive and non-invasive arterial procedures. Therefore, different variations concerning the LGA and inferior phrenic artery should be considered during surgical and non-surgical evaluations.

Phrenic Arterial Injury Presenting as Delayed Hemothorax Complicating Simple Rib Fracture.

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Ahn, Hong Joon; Lee, Jun Wan; Kim, Kun Dong; You, In Sool

2016-04-01

Delayed hemothorax after blunt torso injury is rare, but might be associated with significant morbidity and mortality. We present a case of delayed hemothorax bleeding from phrenic artery injury in a 24-year-old woman. The patient suffered from multiple rib fractures on the right side, a right hemopneumothorax, thoracic vertebral injury and a pelvic bone fracture after a fall from a fourth floor window. Delayed hemothorax associated with phrenic artery bleeding, caused by a stab injury from a fractured rib segment, was treated successfully by a minimally invasive thoracoscopic surgery. Here, we have shown that fracture of a lower rib or ribs might be accompanied by delayed massive hemothorax that can be rapidly identified and promptly managed by thoracoscopic means.

Origin of a common trunk for the inferior phrenic arteries from the right renal artery: a new anatomic vascular variant with clinical implications.

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Topaz, On; Topaz, Allyne; Polkampally, Pritam R; Damiano, Thomas; King, Christopher A

2010-01-01

The inferior phrenic arteries constitute a pair of important vessels, supplying multiple organs including the diaphragm, adrenal glands, esophagus, stomach, liver, inferior vena cava, and retroperitoneum. The vast majority (80-90%) of inferior phrenic arteries originate as separate vessels with near equal frequency from either the abdominal aorta or the celiac trunk. Infrequently, the right and left inferior phrenic arteries can arise in the form of a common trunk from the aorta or from the celiac trunk. We herein present three patients with a new anatomic vascular variant: a common trunk of the inferior phrenic arteries arising from the right renal artery. In one case, the left inferior phrenic branch of the common trunk provided collaterals connecting with a supra-diaphragmatic branch of the left internal mammary artery and in another with the lateral wall of the pericardium. Angiographic identification of a common trunk for the inferior phrenic arteries arising from the right renal artery is important for proper diagnosis and clinical management. The presence of this unique vascular variant can impact revascularization of the renal arteries. Published by Elsevier Inc.

Hepatocellular carcinomas supplied by inferior phrenic arteries.

Science.gov (United States)

Tanabe, N; Iwasaki, T; Chida, N; Suzuki, S; Akahane, T; Kobayashi, N; Ishii, M; Toyota, T

1998-07-01

To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA). A total of 126 consecutive cases of HCC were studied by contract-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment. In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 1, 1, and 4. HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography.

Hepatocellular carcinomas supplied by inferior phrenic arteries

International Nuclear Information System (INIS)

Tanabe, N.; Iwasaki, T.; Akahane, T.; Kobayashi, N.; Ishii, M.; Toyota, T.; Chida, N.; Suzuki, S.

1998-01-01

Purpose: To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA). Material and Methods: A total of 126 consecutive cases of HCC were studied by contrast-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment. Results: In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 7, 1, and 4. Conclusion: HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography. (orig.)

Hepatocellular carcinomas supplied by inferior phrenic arteries

Energy Technology Data Exchange (ETDEWEB)

Tanabe, N.; Iwasaki, T.; Akahane, T.; Kobayashi, N.; Ishii, M.; Toyota, T. [Tohoku Univ. School of Medicine (Japan). Third Dept. of Internal Medicine; Chida, N.; Suzuki, S. [National Sendai Hospital (Japan). Dept. of Gastroenterology

1998-07-01

Purpose: To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA). Material and Methods: A total of 126 consecutive cases of HCC were studied by contrast-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment. Results: In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 7, 1, and 4. Conclusion: HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography. (orig.)

Super-response to cardiac resynchronization therapy may predict late phrenic nerve stimulation.

Science.gov (United States)

Juliá, Justo; López-Gil, María; Fontenla, Adolfo; Lozano, Álvaro; Villagraz, Lola; Salguero, Rafael; Arribas, Fernando

2017-11-22

Changes in the anatomical relationship between left phrenic nerve and coronary veins may occur due to the reverse remodelling observed in super-responders to cardiac resynchronization therapy (CRT) and might be the underlying mechanism in patients developing late-onset phrenic nerve stimulation (PNS) without evidence of lead dislodgement (LD). In this study, we sought to evaluate the role of super-response (SR) to CRT as a potential predictor of late-onset PNS. Consecutive patients implanted with a left ventricular (LV) lead in a single centre were retrospectively analysed. Phrenic nerve stimulation was classified as 'early' when it occurred within 3 months of implantation and 'late' for occurrences thereafter. 'Late' PNS was considered related to LD (LD-PNS) when LV threshold differed by > 1 V or impedance >250 Ω from baseline values or in case of radiological displacement. Cases not meeting the former criteria were classified as 'non-LD-PNS'. Super-response was defined as a decrease ≥30% of the left ventricluar end-systolic volume at 1-year echocardiography. At 32 ± 7 months follow-up, PNS occurred in 20 of 139 patients. Late non-LD-PNS incidence was significantly higher in the SR group (8/61; 13.1%) when compared with the non-SR (1/78; 1.3%) (P = 0.010). Super-response remained the only predictor of non-LD-PNS at multivariate analysis (odds ratio: 11.62, 95% confidence interval 1.41-95.68, P = 0.023). Incidence of late non-LD-PNS is higher among SR to CRT, suggesting a potential role of the changes in the anatomical relationship between left phrenic nerve and coronary veins. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

CT and angiographic appearances of hepatocellular carcinoma partially fed by right inferior phrenic artery

Energy Technology Data Exchange (ETDEWEB)

Ohtomo, Kuni; Furui, Shigeru; Yoshikawa, Hiroki; Yashiro, Naofumi; Araki, Tsutomu [Tokyo Univ. (Japan). Faculty of Medicine

1983-04-01

CT and angiographic appearances of 8 hepatocellular carcinomas which were partially fed by right inferior phrenic artery were discussed. CT demonstrated tumor fully occupied posterior segment of right hepatic lobe in 6 cases which were composed of 3 solitary massive, 2 massive nodular and 1 confluent massive angiographically. In the other 2 cases, CT showed encapsulated tumor in posterior inferior portion of posterior segment protruded from the liver. In 6 out of these 8 cases, tumor vessels and tumor stain were chiefly derived from posterior branch of right inferior phrenic artery.

CT and angiographic appearances of hepatocellular carcinoma partially feeded by right inferior phrenic artery

International Nuclear Information System (INIS)

Ohtomo, Kuni; Furui, Shigeru; Yoshikawa, Hiroki; Yashiro, Naofumi; Araki, Tsutomu

1983-01-01

CT and angiographic appearances of 8 hepatocellular carcinomas which were partially feeded by right inferior phrenic artery were discussed. CT demonstrated tumor fully occupied posterior segment of right hepatic lobe in 6 cases which were composed of 3 solitary massive, 2 massive nodular and 1 confluent massive angiographically. In the other 2 cases, CT showed encapsulated tumor in posterior inferior portion of posterior segment protruded from the liver. In 6 out of these 8 cases, tumor vessels and tumor stain were chiefly derived from posterior branch of right inferior phrenic artery. (author)

Long-lasting amelioration of walking trajectory in neglect after prismatic adaptation

Directory of Open Access Journals (Sweden)

Marco eRabuffetti

2013-07-01

Full Text Available In the present investigation we explored the effect of prismatic adaptation (PA applied to the upper right limb on the walking trajectory of a neglect patient with more severe neglect in far than in near space. The patient was asked to bisect a line fixed to the floor by walking across it before and after four sessions of PA distributed over a time frame of 67 days. Gait path was analysed by means of an optoelectronic motion analysis system.The walking trajectory improved following PA and the result was maintained at follow-up, fifteen months after treatment. The improvement was greater for the predicted bisection error (estimated on the basis of the trajectory extrapolated from the first walking step then for the observed bisection error (measured at line crossing.These results show that PA may act on high level spatial representation of gait trajectory rather than on lower level sensory-motor gait components and suggest that PA may have a long lasting rehabilitative effect on neglect patients showing a deviated walking trajectory.

Low vulnerability of the right phrenic nerve to electroporation ablation

NARCIS (Netherlands)

van Driel, Vincent J. H. M.; Neven, KGEJ; van Wessel, Harri; Vink, Aryan; Doevendans, Pieter A. F. M.; Wittkampf, Fred H. M.

BACKGROUND Circular electroporation ablation is a novel ablation modality for electrical pulmonary vein isolation. With a single 200-3 application, deep circular myocardial lesions can be created. However, the acute and chronic effects of this energy source on phrenic nerve (PN) function are

Recurrent intractable hiccups treated by cervical phrenic nerve block under electromyography: report of a case.

Science.gov (United States)

Sa, Young Jo; Song, Dae Heon; Kim, Jae Jun; Kim, Young Du; Kim, Chi Kyung; Moon, Seok Whan

2015-11-01

Intractable or persistent hiccups require intensive or invasive treatments. The use of a phrenic nerve block or destructive treatment for intractable hiccups has been reported to be a useful and discrete method that might be valuable to patients with this distressing problem and for whom diverse management efforts have failed. We herein report a successful treatment using a removable and adjustable ligature for the phrenic nerve in a patient with recurrent and intractable hiccups, which was employed under the guidance of electromyography.

Long-lasting desynchronization in rat hippocampal slice induced by coordinated reset stimulation

International Nuclear Information System (INIS)

Tass, P. A.; Barnikol, U. B.; Silchenko, A. N.; Hauptmann, C.; Speckmann, E.-J.

2009-01-01

In computational models it has been shown that appropriate stimulation protocols may reshape the connectivity pattern of neural or oscillator networks with synaptic plasticity in a way that the network learns or unlearns strong synchronization. The underlying mechanism is that a network is shifted from one attractor to another, so that long-lasting stimulation effects are caused which persist after the cessation of stimulation. Here we study long-lasting effects of multisite electrical stimulation in a rat hippocampal slice rendered epileptic by magnesium withdrawal. We show that desynchronizing coordinated reset stimulation causes a long-lasting desynchronization between hippocampal neuronal populations together with a widespread decrease in the amplitude of the epileptiform activity. In contrast, periodic stimulation induces a long-lasting increase in both synchronization and amplitude.

Unilateral phrenic nerve stimulation for neurogenic hypoventilation in Arnold Chiari malformation

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Nitin Garg

2013-01-01

Full Text Available Long- term ventilator dependence in patients with neurogenic hypoventilation is associated with significant morbidity and restricts mobility. Diaphragmatic pacing by phrenic nerve stimulation (PNS is a viable alternative. This is a case report of patient with Arnold-Chiari malformation with extensive syrinx who had neurogenic hypoventilation during sleep even after foramen magnum decompression and resolution of the syrinx. Unilateral PNS was done using spinal cord stimulator. With intermittent stimulation for 8 h while asleep, patient could be weaned off the ventilator completely. At 2 years follow- up, patient is ambulant and has returned to his routine activities. PNS is a good treatment tool in patients with neurogenic hypoventilation. Spinal cord stimulator can be used with optimal results. This is first such reported case of using spinal cord stimulator for PNS from India.

Pleural and Pulmonary Staining at Inferior Phrenic Arteriography Mimicking a Tumor Staining of Hepatocellular Carcinoma

International Nuclear Information System (INIS)

Lee, Deok Hee; Hwang, Jae Cheol; Lim, Soo Mee; Yoon, Hyun-Ki; Sung, Kyu-Bo; Song, Ho-Young

2000-01-01

Purpose: To describe the findings of pleural and pulmonary staining of the inferior phrenic artery, which can be confused with tumor staining during transarterial chemoembolization (TACE) of hepatoma.Methods: Fifteen patients who showed pleural and pulmonary staining without relationship to hepatic masses at inferior phrenic arteriography were enrolled. The staining was noted at initial TACE (n = 8), at successive TACE (n = 5), and after hepatic surgery (n = 2). The angiographic pattern, the presence of pleural change on computed tomography (CT), and clinical history were evaluated.Results: Draining pulmonary veins were seen in all cases. The lower margin of the staining corresponded to the lower margin of the pleura in 10 patients. CT showed pleural and/or pulmonary abnormalities in all cases. After embolization of the inferior phrenic artery, the accumulation of iodized oil in the lung was noted.Conclusion: Understanding the CT and angiographic findings of pleural and pulmonary staining during TACE may help differentiate benign staining from tumor staining

The Anterior Branch of the Left Inferior Phrenic Artery Arising from the Right Inferior Phrenic Artery: An Angiographic and CT Study

International Nuclear Information System (INIS)

Hieda, Masashi; Toyota, Naoyuki; Kakizawa, Hideaki; Ishikawa, Masaki; Horiguchi, Jun; Ito, Katsuhide

2009-01-01

The purpose of this study was to retrospectively analyze the frequency and anatomical pattern of the anterior branch of the left inferior phrenic artery (LIPA) arising from the right inferior phrenic artery (RIPA). Angiography of the RIPA for patients (n = 140) with hepatic malignancy was retrospectively reviewed. The frequency at which the anterior branch of the LIPA arose from the RIPA was 14.3% (20 of 140 patients [pts]). Among the three branches that may arise from the RIPA in these cases (the anterior branch of the LIPA and the anterior and posterior branches of the RIPA), the anterior branch of the LIPA was the first branch of the RIPA in 9 of 20 pts (45%), and the posterior branch of the RIPA in 11 of 20 pts (55%). The anterior branch of the LIPA ran along the ventral side of the esophagus or stomach and supplied the esophagogastric region and dome of the left diaphragm in all cases. In conclusion, the anterior branch of the LIPA arises from the RIPA at a comparatively high frequency. In embolization of the RIPA, to effectively treat and avoid possible complications, interventionalists should be aware of this potential variant anatomy.

Mechanisms of translation control underlying long-lasting synaptic plasticity and the consolidation of long-term memory.

Science.gov (United States)

Santini, Emanuela; Huynh, Thu N; Klann, Eric

2014-01-01

The complexity of memory formation and its persistence is a phenomenon that has been studied intensely for centuries. Memory exists in many forms and is stored in various brain regions. Generally speaking, memories are reorganized into broadly distributed cortical networks over time through systems level consolidation. At the cellular level, storage of information is believed to initially occur via altered synaptic strength by processes such as long-term potentiation. New protein synthesis is required for long-lasting synaptic plasticity as well as for the formation of long-term memory. The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of cap-dependent protein synthesis and is required for numerous forms of long-lasting synaptic plasticity and long-term memory. As such, the study of mTORC1 and protein factors that control translation initiation and elongation has enhanced our understanding of how the process of protein synthesis is regulated during memory formation. Herein we discuss the molecular mechanisms that regulate protein synthesis as well as pharmacological and genetic manipulations that demonstrate the requirement for proper translational control in long-lasting synaptic plasticity and long-term memory formation. © 2014 Elsevier Inc. All rights reserved.

Marked lateral deviation of the phrenic nerve due to variant origin and course of the thyrocervical trunk: a cadaveric study.

Science.gov (United States)

Ogami, Keiko; Saiki, K; Okamoto, K; Wakebe, T; Manabe, Y; Imamura, T; Tsurumoto, T

2016-05-01

Phrenic nerve impairment can often lead to serious respiratory disorders under various pathological conditions. During routine dissection of an 88-year-old Japanese male cadaver, a victim of heart failure, we recognized an extremely rare variation of the right thyrocervical trunk arising from the subclavian artery laterally to the anterior scalene muscle. In addition to that, the ipsilateral phrenic nerve was drawn and displaced remarkably laterad by this vessel. We examined all of the branches arising from subclavian arteries, phrenic nerves and diaphragm muscles. The embryological background of this arterial variation is considered. The marked displacement with prolonged strain had a potential to cause phrenic nerve impairment with an atrophic change of the diaphragm muscle. Recently many image diagnostic technologies have been developed and are often used. However, it is still possible that rare variations like this case may be overlooked and can only be recognized by intimate regional examination while keeping these rare variations in mind.

Laryngeal and phrenic nerve involvement in a patient with hereditary neuropathy with liability to pressure palsies (HNPP).

Science.gov (United States)

Cortese, A; Piccolo, G; Lozza, A; Schreiber, A; Callegari, I; Moglia, A; Alfonsi, E; Pareyson, D

2016-07-01

Lower cranial and phrenic nerve involvement is exceptional in hereditary neuropathy with liability to pressure palsies (HNPP). Here we report the occurrence of reversible laryngeal and phrenic nerve involvement in a patient with HNPP. The patient recalled several episodes of reversible weakness and numbness of his feet and hands since the age of 30 years. His medical history was uneventful, apart from chronic obstructive pulmonary disease (COPD). At age 44, following severe weight loss, he presented with progressive dysphonia and hoarseness. EMG of cricoarytenoid and thyroarytenoid muscles and laryngeal fibroscopy confirmed vocal cord paralysis. These speech disturbances gradually regressed. Two years later, he reported rapidly worsening dyspnea. Electroneurography showed increased distal latency of the right phrenic nerve and diaphragm ultrasonography documented reduced right hemi-diaphragm excursion. Six months later and after optimization of CODP treatment, his respiratory function had improved and both phrenic nerve conduction and diaphragm excursion were completely restored. We hypothesize that chronic cough and nerve stretching in the context of CODP, together with severe weight loss, may have triggered the nerve paralysis in this patient. Our report highlights the need for optimal management of comorbidities such as CODP as well as careful control of weight in HNPP patients to avoid potentially harmful complications. Copyright © 2016 Elsevier B.V. All rights reserved.

Can bilateral bronchospasm be a sign of unilateral phrenic nerve palsy after supraclavicular brachial plexus block?

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Souvik Chaudhuri

2012-01-01

Full Text Available Ultrasound-guided peripheral nerve blocks facilitate ambulatory anesthesia for upper limb surgeries. Unilateral phrenic nerve blockade is a common complication after interscalene brachial plexus block, rather than the supraclavicular block. We report a case of severe respiratory distress and bilateral bronchospasm following ultrasound-guided supraclavicular brachial plexus block. Patient did not have clinical features of pneumothorax or drug allergy and was managed with oxygen therapy and salbutamol nebulization. Chest X-ray revealed elevated right hemidiaphragm confirming unilateral phrenic nerve paresis.

Mechanism to preserve phrenic nerve function during photosensitization reaction: drug uptake and photosensitization reaction effect on electric propagation

Science.gov (United States)

Takahashi, Haruka; Hamada, Risa; Ogawa, Emiyu; Arai, Tsunenori

2018-02-01

To study a mechanism of phrenic nerve preservation phenomena during a photosensitization reaction, we investigated an uptake of talaporfin sodium and photosensitization reaction effect on an electric propagation. Right phrenic nerve was completely preserved after superior vena cava isolations using the photosensitization reaction in canine animal experiments, in spite of adjacent myocardium was electrically blocked. We predicted that low drug uptake and/or low photosensitization reaction effect on the nerve might be a mechanism of that phenomena. To investigate uptake to various nerve tissue, a healthy extracted crayfish ventral nerve cord and an extracted porcine phrenic nerve were immersed in 20 μg/ml talaporfin sodium solution for 0-240 min. The mean talaporfin sodium fluorescence brightness increased depending on the immersion time. This brightness saturated around the immersion time of 120 min. We found that talaporfin sodium uptake inside the perineurium which directly related to the electric propagation function was lower than that of outside in the porcine phrenic nerve. To investigate photosensitization reaction effect on electric propagation, the crayfish nerve was immersed into the same solution for 15 min and irradiated by a 663 nm laser light with 120 mW/cm2. Since we found the action potential disappeared when the irradiation time was 25-65 s, we consider that the crayfish nerve does not tolerant to the photosensitization reaction on electric propagation function at atmospheric pressure. From these results, we think that the low uptake of talaporfin sodium inside the perineurium and low oxygen partial pressure of nerve might be the possible mechanism to preserve phrenic nerve in vivo.

Morphometric analysis of the phrenic nerve in male and female Wistar-Kyoto (WKY and spontaneously hypertensive rats (SHR

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A.R. Rodrigues

2011-06-01

Full Text Available Ventilatory differences between rat strains and genders have been described but the morphology of the phrenic nerve has not been investigated in spontaneously hypertensive (SHR and normotensive Wistar-Kyoto (WKY rats. A descriptive and morphometric study of the phrenic nerves of male (N = 8 and female (N = 9 SHR, and male (N = 5 and female (N = 6 WKY is presented. After arterial pressure and heart rate recordings, the phrenic nerves of 20-week-old animals were prepared for epoxy resin embedding and light microscopy. Morphometric analysis performed with the aid of computer software that took into consideration the fascicle area and diameter, as well as myelinated fiber profile and Schwann cell nucleus number per area. Phrenic nerves were generally larger in males than in females on both strains but larger in WKY compared to SHR for both genders. Myelinated fiber numbers (male SHR = 228 ± 13; female SHR = 258 ± 4; male WKY = 382 ± 23; female WKY = 442 ± 11 for proximal right segments and density (N/mm²; male SHR = 7048 ± 537; female SHR = 10355 ± 359; male WKY = 9457 ± 1437; female WKY = 14351 ± 1448 for proximal right segments were significantly larger in females of both groups and remarkably larger in WKY than SHR for both genders. Strain and gender differences in phrenic nerve myelinated fiber number are described for the first time in this experimental model of hypertension, indicating the need for thorough functional studies of this nerve in male and female SHR.

Phrenic nerve stimulation during neck dissection for advanced thyroid cancer involving level IV: is it worth doing it?

Science.gov (United States)

Duque, Carlos S; Dueñas, Juan P; Marulanda, Marcela; Pérez, Diana; Londoňo, Andres; Roy, Soham; Khadem, Mai Al

2017-03-01

During thyroidectomy and neck dissection surgery for advanced or recurrent metastatic thyroid cancer under intraoperative monitoring, we used the available technology to assess the feasibility of such an intervention to monitor those patients with phrenic nerves at risk. A retrospective review of patients operated on from January 2009 to December 2015 by a single surgeon (CSD) was conducted. Patients who had neck and mediastinal dissection, with or without total thyroidectomy, due to advanced or recurrent metastatic disease to the neck were selected. The procedures were done under intraoperative nerve monitoring using nerve monitoring systems (NIM 2.0 or 3.0; Medtronic, Jacksonville, FL, USA). A total of 19 patients were included in the study, with a mean age of 57.6 years ± 16.3 and a male/female ratio of 10:9. Overall, all patients had an intact phrenic nerve at the conclusion of the surgery. One patient had an aggressive tumor that precluded sacrifice of the left recurrent laryngeal nerve and ipsilateral thoracic duct. The procedure was complicated by a temporary impairment of the diaphragm contraction with intraoperative nerve monitoring as well as a chyle fistula. This was due to the manipulation of the tissue surrounding the phrenic nerve. Intraoperative nerve monitoring of the phrenic nerve offers the surgeon a "potential" method of ensuring phrenic nerve integrity in cases of advanced thyroid cancers with gross level IV metastatic disease. Further prospective studies are needed to assess the risks of this intervention and evaluate the method of recording diaphragm contraction movement.

Phrenic nerve decompression for the management of unilateral diaphragmatic paralysis - preoperative evaluation and operative technique.

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Hoshide, Reid; Brown, Justin

2017-01-01

Unilateral diaphragmatic paralysis (UDP) can be a very disabling, typically causing shortness of breath and reduced exercise tolerance. We present a case of a surgical decompression of the phrenic nerve of a patient who presented with UDP, which occurred following cervical spine surgery. The workup for the etiology of UDP demonstrated paradoxical movement on "sniff test" and notably impaired pulmonary function tests. Seven months following the onset of the UDP, he underwent a surgical decompression of the phrenic nerve at the level of the anterior scalene. He noted rapid symptomatic improvement following surgery and reversal of the above noted objective findings was documented. At his 4-year follow-up, he had complete resolution of his clinical symptoms. Repeated physiologic testing of his respiratory function had shown a complete reversal of his UDP. Anatomical compression of the phrenic nerve by redundant neck vasculature should be considered in the differential diagnosis of UDP. Here we demonstrated the techniques in workup and surgical management, with both subjective and objective evidence of success.

End-to-side neurotization with the phrenic nerve in restoring the function of toe extension: an experimental study in a rat model.

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Jia, Xiaotian; Chen, Chao; Yang, Jianyun; Yu, Cong

2018-06-01

The phrenic nerve being transferred to the posterior division of the lower trunk with end-to-end neurorrhaphy is reported to be effective in restoring the function of digit extension in literature. However, the phrenic nerve is extremely important in respiration. We designed an animal experiment to discover whether the phrenic nerve being transferred to the posterior division of the lower trunk with end-to-side neurotization was feasible and provided the theoretical basis. A sum of 36 Sprague-Dawley rats was randomly assigned to one of two groups. In Group A, the phrenic nerve was transferred to the posterior division of the lower trunk with end-to-side neurotization. In Group B, the posterior division of the lower trunk was directly sutured. The results of behavioral assessment, electrophysiology, histology and nerve fiber count and muscle weight at 12 weeks postoperatively were recorded. In Group A, none of the rats experienced tachypnea. The motion of slight toe extension was observed. The results of electrophysiology, histology and nerve fiber count and muscle weight in Group A were not as well as those of Group B, but gradually improved with time. The phrenic nerve being transferred to the posterior division of lower trunk with end-to-side neurotization can partially restore the function of toe extension in a rat model. Whether the function of digit extension can be restored by the phrenic nerve with end-to-side neurotization in humans still needs more practice in clinic.

Theophylline-induced respiratory recovery following cervical spinal cord hemisection is augmented by serotonin 2 receptor stimulation.

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Basura, Gregory J; Nantwi, Kwaku D; Goshgarian, Harry G

2002-11-22

Cervical spinal cord hemisection leads to a disruption of bulbospinal innervation of phrenic motoneurons resulting in paralysis of the ipsilateral hemidiaphragm. We have previously demonstrated separate therapeutic roles for theophylline, and more recently serotonin (5-HT) as modulators to phrenic nerve motor recovery; mechanisms that likely occur via adenosine A1 and 5-HT2 receptors, respectively. The present study was designed to specifically determine if concurrent stimulation of 5-HT2 receptors may enhance motor recovery induced by theophylline alone. Adult female rats (250-350 g; n=7 per group) received a left cervical (C2) hemisection that resulted in paralysis of the ipsilateral hemidiaphragm. Twenty-four hours later rats were given systemic theophylline (15 mg/kg, i.v.), resulting in burst recovery in the ipsilateral phrenic nerve. Theophylline-induced recovery was enhanced with the 5-HT2A/2C receptor agonist, (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI; 1.0 mg/kg). DOI-evoked augmentation of theophylline-induced recovery was attenuated following subsequent injection of the 5-HT2 receptor antagonist, ketanserin (2.0 mg/kg). In a separate group, rats were pretreated with ketanserin, which did not prevent subsequent theophylline-induced respiratory recovery. However, pretreatment with ketanserin did prevent DOI-induced augmentation of the theophylline-evoked phrenic nerve burst recovery. Lastly, using immunocytochemistry and in situ hybridization, we showed for the first time a positive co-localization of adenosine A1 receptor mRNA and immunoreactivity with phrenic motoneurons of the cervical ventral horns. Taken together, the results of the present study suggest that theophylline may induce motor recovery likely at adenosine A1 receptors located at the level of the spinal cord, and the concurrent stimulation of converging 5-HT2 receptors may augment the response.

In patients with a tumour invading the phrenic nerve does prophylactic diaphragm plication improve postoperative lung function?

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Beattie, Gwyn W; Dunn, William G; Asif, Mohammed

2016-09-01

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'In patients with tumours involving the phrenic nerve, does prophylactic diaphragm plication improve lung function following tumour resection?' Using the reported search, 258 papers were found of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Three case reports and one case series represent 37 patients in the literature along with two relevant animal studies. Patients treated with prophylactic plication at the time of injury or sacrifice of the phrenic nerve had reduced radiological evidence of diaphragm paralysis, lower reported shortness of breath and reduced requirement for ventilatory support. In patients with prophylactic diaphragm plication and a concurrent pulmonary resection, the predicted postoperative lung function correlated closely with the postoperative measured FEV1, FVC and gas transfer. The postoperative measured FEV1 was reported as 86-98%, the FVC 82-89% and gas transfer 97% of the predicted values. Two animal models investigate the mechanics of respiration, spirometry and gas exchange following diaphragmatic plication. A randomized control study in four dogs measured a 50% reduction in tidal volume and respiratory rate, a 40% decrease in arterial PO2 and a 43% increase in arterial CO2 when the phrenic nerve was crushed in animals with a pneumonectomy but without prophylactic diaphragm plication. A further randomized control animal study with 28 dogs found that plicating the diaphragm after unilateral phrenic nerve transection resulted in a significant increase in tidal volume and lung compliance and a significant decrease in respiratory frequency and the work of breathing. Prophylactic diaphragm plication may preserve lung function, reduce the risk of

Early hemi-diaphragmatic plication through a video assisted mini-thoracotomy in postcardiotomy phrenic nerve paresis

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Tsakiridis, Kosmas; Visouli, Aikaterini N.; Machairiotis, Nikolaos; Christofis, Christos; Stylianaki, Aikaterini; Katsikogiannis, Nikolaos; Mpakas, Andreas; Courcoutsakis, Nicolaos; Zarogoulidis, Konstantinos

2012-01-01

New symptom onset of respiratory distress without other cause, and new hemi-diaphragmatic elevation on chest radiography postcardiotomy, are usually adequate for the diagnosis of phrenic nerve paresis. The symptom severity varies (asymptomatic state to severe respiratory failure) depending on the degree of the lesion (paresis vs. paralysis), the laterality (unilateral or bilateral), the age, and the co-morbidity (respiratory, cardiac disease, morbid obesity, etc). Surgical treatment (hemi-diaphragmatic plication) is indicated only in the presence of symptoms. The established surgical treatment is plication of the affected hemidiaphragm which is generally considered safe and effective. Several techniques and approaches are employed for diaphragmatic plication (thoracotomy, video-assisted thoracoscopic surgery, video-assisted mini-thoracotomy, laparoscopic surgery). The timing of surgery depends on the severity and the progression of symptoms. In infants and young children with postcardiotomy phrenic nerve paresis the clinical status is usually severe (failure to wean from mechanical ventilation), and early plication is indicated. Adults with postcardiotomy phrenic nerve paresis usually suffer from chronic dyspnoea, and, in the absence of respiratory distress, conservative treatment is recommended for 6 months -2 years, since improvement is often observed. Nevertheless, earlier surgical treatment may be indicated in non-resolving respiratory failure. We present early (25th day postcardiotomy) right hemi-diaphragm plication, through a video assisted mini-thoracotomy in a high risk patient with postcardiotomy phrenic nerve paresis and respiratory distress. Early surgery with minimal surgical trauma, short operative time, minimal blood loss and postoperative pain, led to fast rehabilitation and avoidance of prolonged hospitalization complications. The relevant literature is discussed. PMID:23304442

Phrenic nerve injury: An underrecognized and potentially preventable complication of pulmonary vein isolation using a wide-area circumferential ablation approach.

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Yong Ji, Sang; Dewire, Jane; Barcelon, Bernadette; Philips, Binu; Catanzaro, John; Nazarian, Saman; Cheng, Alan; Spragg, David; Tandri, Harikrishna; Bansal, Sandeep; Ashikaga, Hiroshi; Rickard, Jack; Kolandaivelu, Aravindan; Sinha, Sunil; Marine, Joseph E; Calkins, Hugh; Berger, Ronald

2013-10-01

Phrenic nerve injury (PNI) is a well-known, although uncommon, complication of pulmonary vein isolation (PVI) using radiofrequency energy. Currently, there is no consensus about how to avoid or minimize this injury. The purpose of this study was to determine how often the phrenic nerve, as identified using a high-output pacing, lies along the ablation trajectory of a wide-area circumferential lesion set. We also sought to determine if PVI can be achieved without phrenic nerve injury by modifying the ablation lesion set so as to avoid those areas where phrenic nerve capture (PNC) is observed. We prospectively enrolled 100 consecutive patients (age 61.7 ± 9.2 years old, 75 men) who underwent RF PVI using a wide-area circumferential ablation approach. A high-output (20 mA at 2 milliseconds) endocardial pacing protocol was performed around the right pulmonary veins and the carina where a usual ablation lesion set would be made. A total of 30% of patients had PNC and required modification of ablation lines. In the group of patients with PNC, the carina was the most common site of capture (85%) followed by anterior right superior pulmonary vein (RSPV) (70%) and anterior right inferior pulmonary vein (RIPV) (30%). A total of 25% of PNC group had capture in all 3 (RSPV, RIPV, and carina) regions. There was no difference in the clinical characteristics between the groups with and without PNC. RF PVI caused no PNI in either group. High output pacing around the right pulmonary veins and the carina reveals that the phrenic nerve lies along a wide-area circumferential ablation trajectory in 30% of patients. Modification of ablation lines to avoid these sites may prevent phrenic nerve injury during RF PVI. © 2013 Wiley Periodicals, Inc.

The phrenic nerve as a donor for brachial plexus injuries: is it safe and effective? Case series and literature analysis.

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Socolovsky, Mariano; di Masi, Gilda; Bonilla, Gonzalo; Domínguez Paez, Miguel; Robla, Javier; Calvache Cabrera, Camilo

2015-06-01

Controversy exists surrounding the use of the phrenic nerve for transfer in severe brachial plexus injuries. The objectives of this study are: (1) to present the experience of the authors using the phrenic nerve in a single institution; and (2) to thoroughly review the existing literature to date. Adult patients with C5-D1 and C5-C8 lesions and a phrenic nerve transfer were retrospectively included. Patients with follow-up shorter than 18 months were excluded. The MRC muscle strength grading system was used to rate the outcome. Clinical repercussions relating to sectioning of the phrenic nerve were studied. An intense rehabilitation program was started after surgery, and compliance to this program was monitored using a previously described scale. Statistical analysis was performed with the obtained data. Fifty-one patients were included. The mean time between trauma and surgery was 5.7 months. Three-quarters of the patients had C5-D1, with the remainder C5-C8. Mean post-operative follow-up was 32.5 months A MRC of M4 was achieved in 62.7% patients, M3 21.6%, M2 in 3.9%, and M1 in 11.8%. The only significant differences between the two groups were in graft length (9.8 vs. 15.1 cm, p = 0.01); and in the rehabilitation compliance score (2.86 vs. 2.00, p = 0.01). Results of phrenic nerve transfer are predictable and good, especially if the grafts are short and the rehabilitation is adequate. It may adversely affect respiratory function tests, but this rarely correlates clinically. Contraindications to the use of the phrenic nerve exist and should be respected.

Occurrence of phrenic nerve stimulation in cardiac resynchronization therapy patients: the role of left ventricular lead type and placement site.

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Biffi, Mauro; Exner, Derek V; Crossley, George H; Ramza, Brian; Coutu, Benoit; Tomassoni, Gery; Kranig, Wolfgang; Li, Shelby; Kristiansen, Nina; Voss, Frederik

2013-01-01

Unwanted phrenic nerve stimulation (PNS) has been reported in ∼1 in 4 patients undergoing left ventricular (LV) pacing. The occurrence of PNS over mid-term follow-up and the significance of PNS are less certain. Data from 1307 patients enrolled in pre-market studies of LV leads manufactured by Medtronic (models 4193 and 4195 unipolar, 4194, 4196, 4296, and 4396 bipolar) were pooled. Left ventricular lead location was recorded at implant using a common classification scheme. Phrenic nerve stimulation symptoms were either spontaneously reported or identified at scheduled follow-up visits. A PNS-related complication was defined as PNS resulting in invasive intervention or the termination of LV pacing. Average follow-up was 14.9 months (range 0.0-46.6). Phrenic nerve stimulation symptoms occurred in 169 patients (12.9%). Phrenic nerve stimulation-related complications occurred in 21 of 1307 patients (1.6%); 16 of 738 (2.2%) in the unipolar lead studies, and 5 of 569 (0.9%) in the bipolar lead studies (P = 0.08). Phrenic nerve stimulation was more frequent at middle-lateral/posterior, and apical LV sites (139/1010) vs. basal-posterior/lateral/anterior, and middle-anterior sites (20/297; P= 0.01). As compared with an anterior LV lead position, a lateral LV pacing site was associated with over a four-fold higher risk of PNS (P= 0.005) and an apical LV pacing site was associated with over six-fold higher risk of PNS (P= 0.001). Phrenic nerve stimulation occurred in 13% of patients undergoing LV lead placement and was more common at mid-lateral/posterior, and LV apical sites. Most cases (123/139; 88%) of PNS were mitigated via electrical reprogramming, without the need for invasive intervention.

The novelty-seeking phenotype modulates the long-lasting effects of intermittent ethanol administration during adolescence.

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Sandra Montagud-Romero

Full Text Available The aim of the present study was to investigate if a novelty-seeking phenotype mediates the long-lasting consequences of intermittent EtOH intoxication during adolescence. The hole board test was employed to classify adolescent mice as High- or Low-Novelty Seekers. Subsequently, animals were administered ethanol (1.25 or 2.5 g/kg on two consecutive days at 48-h intervals over a 14-day period. Anxiety levels--measured using the elevated plus maze- spontaneous motor activity and social interaction test were studied 3 weeks later. A different set of mice underwent the same procedure, but received only the 2.5 g/kg dose of ethanol. Three weeks later, in order to induce CPP, the same animals were administered 1 or 6 mg/kg of cocaine or 1 or 2.5 mg/kg MDMA. The results revealed a decrease in aggressive behaviors and an anxiolytic profile in HNS mice and longer latency to explore the novel object by LNS mice. Ethanol exposure enhanced the reinforcing effects of cocaine and MDMA in both groups when CPP was induced with a sub-threshold dose of the drugs. The extinguished cocaine-induced CPP (1 and 6 mg/kg was reinstated after a priming dose in HNS animals only. Our results confirm that intermittent EtOH administration during adolescence induces long-lasting effects that are manifested in adult life, and that there is an association between these effects and the novelty-seeking phenotype.

Phrenic nerve block caused by interscalene brachial plexus block: breathing effects of different sites of injection.

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Bergmann, Lars; Martini, Stefan; Kesselmeier, Miriam; Armbruster, Wolf; Notheisen, Thomas; Adamzik, Michael; Eichholz, Rϋdiger

2016-07-29

Interscalene brachial plexus (ISB) block is often associated with phrenic nerve block and diaphragmatic paresis. The goal of our study was to test if the anterior or the posterior ultrasound guided approach of the ISB is associated with a lower incidence of phrenic nerve blocks and impaired lung function. This was a prospective, randomized and single-blinded study of 84 patients scheduled for elective shoulder surgery who fullfilled the inclusion and exclusion critereria. Patients were randomized in two groups to receive either the anterior (n = 42) or the posterior (n = 42) approach for ISB. Clinical data were recorded. In both groups patients received ISB with a total injection volume of 15 ml of ropivacaine 1 %. Spirometry was conducted at baseline (T0) and 30 min (T30) after accomplishing the block. Changes in spirometrical variables between T0 and T30 were investigated by Wilcoxon signed-rank test for each puncture approach. The temporal difference between the posterior and the anterior puncture approach groups were again analyzed by the Wilcoxon-Mann-Whitney test. The spirometric results showed a significant decrease in vital capacity, forced expiratory volume per second, and maximum nasal inspiratory breathing after the Interscalene brachial plexus block; indicating a phrenic nerve block (p Wilcoxon signed-rank). A significant difference in the development of the spirometric parameters between the anterior and the posterior group could not be identified (Wilcoxon-Mann-Whitney test). Despite the changes in spirometry, no cases of dyspnea were reported. A different site of injection (anterior or posterior) did not show an effect in reducing the cervical block spread of the local anesthetic and the incidence of phrenic nerve blocks during during ultrasound guided Interscalene brachial plexus block. Clinical breathing effects of phrenic nerve blocks are, however, usually well compensated, and subjective dyspnea did not occur in our patients. German

The phrenic nerve transfer in the treatment of a septuagenarian with brachial plexus avulsion injury: a case report.

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Jiang, Ye; Lao, Jie

2018-05-01

Phrenic nerve transfer has been a well-established procedure for restoring elbow flexion function in patients with brachial plexus avulsion injury. Concerning about probably detrimental respiratory effects brought by the operation, however, stirred up quite a bit of controversy. We present a case report of the successful application of phrenic nerve as donor to reinnervate the biceps in a septuagenarian with brachial plexus avulsion injury, not accompanied with significant clinical respiratory problem.

Phrenic nerve decompression for the management of unilateral diaphragmatic paralysis – preoperative evaluation and operative technique

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Hoshide, Reid; Brown, Justin

2017-01-01

Background: Unilateral diaphragmatic paralysis (UDP) can be a very disabling, typically causing shortness of breath and reduced exercise tolerance. We present a case of a surgical decompression of the phrenic nerve of a patient who presented with UDP, which occurred following cervical spine surgery. Methods: The workup for the etiology of UDP demonstrated paradoxical movement on “sniff test” and notably impaired pulmonary function tests. Seven months following the onset of the UDP, he underwent a surgical decompression of the phrenic nerve at the level of the anterior scalene. Results: He noted rapid symptomatic improvement following surgery and reversal of the above noted objective findings was documented. At his 4-year follow-up, he had complete resolution of his clinical symptoms. Repeated physiologic testing of his respiratory function had shown a complete reversal of his UDP. Conclusions: Anatomical compression of the phrenic nerve by redundant neck vasculature should be considered in the differential diagnosis of UDP. Here we demonstrated the techniques in workup and surgical management, with both subjective and objective evidence of success. PMID:29184705

[Treatment of bilateral vocal cord paralysis by hemi-phrenic nerve transfer].

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Song, W; Li, M; Zheng, H L; Sun, L; Chen, S C; Chen, D H; Liu, F; Zhu, M H; Zhang, C Y; Wang, W

2017-04-07

Objective: To investigate the surgical effect of reinnervation of bilateral posterior cricoarytenoid muscles(PCA) with left hemi-phrenic nerve and endoscopic laser arytenoid resection in bilateral vocal cord fold paralysis(BVFP) and to analyze the pros and cons of the two methods. Methods: One hundred and seventeen BVFP patients who underwent reinnervation of bilateral PCA using the left hemi-phrenic nerve approach (nerve group, n =52) or laser arytenoidectomy(laser group, n =65) were enrolled in this study from Jan.2009 to Dec.2015.Vocal perception evaluation, video stroboscopy, pulmonary function test and laryngeal electromyography were preformed in all patients both preoperatively and postoperative1y.Extubution rate was calculated postoperative1y. Results: Most of the vocal function parameters in nerve group were improved postoperatively compared with preoperative parameters, albeit without a significant difference( P >0.05), while laser group showed a significant deterioration in voice quality postoperative1y( P nerve group was larger than that in laser group ( P nerve group were inhale physiological vocal cord abductions. Postoperative glottal closure showed no significant difference in nerve group ( P >0.05), while showed various increment in laser group( P nerve group and laser group respectively. In both groups, patients presented aspiration symptoms postoperatively, and rdieved soon, except 2 patients in laser group suffered repeated aspiration. Conclusions: Reinnervation of bilateral PCA muscles using left hemi-phrenic nerve can restore inspiratory vocal fold abduction to a satisfactory extent while preserving phonatory function at the preoperative level without evident morbidity, and do not affect swallowing function, greatly improving the quality of life of the patients.

Stimulation of Respiratory Motor Output and Ventilation in a Murine Model of Pompe Disease by Ampakines.

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ElMallah, Mai K; Pagliardini, Silvia; Turner, Sara M; Cerreta, Anthony J; Falk, Darin J; Byrne, Barry J; Greer, John J; Fuller, David D

2015-09-01

Pompe disease results from a mutation in the acid α-glucosidase gene leading to lysosomal glycogen accumulation. Respiratory insufficiency is common, and the current U.S. Food and Drug Administration-approved treatment, enzyme replacement, has limited effectiveness. Ampakines are drugs that enhance α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor responses and can increase respiratory motor drive. Recent work indicates that respiratory motor drive can be blunted in Pompe disease, and thus pharmacologic stimulation of breathing may be beneficial. Using a murine Pompe model with the most severe clinical genotype (the Gaa(-/-) mouse), our primary objective was to test the hypothesis that ampakines can stimulate respiratory motor output and increase ventilation. Our second objective was to confirm that neuropathology was present in Pompe mouse medullary respiratory control neurons. The impact of ampakine CX717 on breathing was determined via phrenic and hypoglossal nerve recordings in anesthetized mice and whole-body plethysmography in unanesthetized mice. The medulla was examined using standard histological methods coupled with immunochemical markers of respiratory control neurons. Ampakine CX717 robustly increased phrenic and hypoglossal inspiratory bursting and reduced respiratory cycle variability in anesthetized Pompe mice, and it increased inspiratory tidal volume in unanesthetized Pompe mice. CX717 did not significantly alter these variables in wild-type mice. Medullary respiratory neurons showed extensive histopathology in Pompe mice. Ampakines stimulate respiratory neuromotor output and ventilation in Pompe mice, and therefore they have potential as an adjunctive therapy in Pompe disease.

Long lasting protein synthesis- and activity-dependent spine shrinkage and elimination after synaptic depression.

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Yazmín Ramiro-Cortés

Full Text Available Neuronal circuits modify their response to synaptic inputs in an experience-dependent fashion. Increases in synaptic weights are accompanied by structural modifications, and activity dependent, long lasting growth of dendritic spines requires new protein synthesis. When multiple spines are potentiated within a dendritic domain, they show dynamic structural plasticity changes, indicating that spines can undergo bidirectional physical modifications. However, it is unclear whether protein synthesis dependent synaptic depression leads to long lasting structural changes. Here, we investigate the structural correlates of protein synthesis dependent long-term depression (LTD mediated by metabotropic glutamate receptors (mGluRs through two-photon imaging of dendritic spines on hippocampal pyramidal neurons. We find that induction of mGluR-LTD leads to robust and long lasting spine shrinkage and elimination that lasts for up to 24 hours. These effects depend on signaling through group I mGluRs, require protein synthesis, and activity. These data reveal a mechanism for long lasting remodeling of synaptic inputs, and offer potential insights into mental retardation.

Spatially dynamic recurrent information flow across long-range dorsal motor network encodes selective motor goals.

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Yoo, Peter E; Hagan, Maureen A; John, Sam E; Opie, Nicholas L; Ordidge, Roger J; O'Brien, Terence J; Oxley, Thomas J; Moffat, Bradford A; Wong, Yan T

2018-03-08

Performing voluntary movements involves many regions of the brain, but it is unknown how they work together to plan and execute specific movements. We recorded high-resolution ultra-high-field blood-oxygen-level-dependent signal during a cued ankle-dorsiflexion task. The spatiotemporal dynamics and the patterns of task-relevant information flow across the dorsal motor network were investigated. We show that task-relevant information appears and decays earlier in the higher order areas of the dorsal motor network then in the primary motor cortex. Furthermore, the results show that task-relevant information is encoded in general initially, and then selective goals are subsequently encoded in specifics subregions across the network. Importantly, the patterns of recurrent information flow across the network vary across different subregions depending on the goal. Recurrent information flow was observed across all higher order areas of the dorsal motor network in the subregions encoding for the current goal. In contrast, only the top-down information flow from the supplementary motor cortex to the frontoparietal regions, with weakened recurrent information flow between the frontoparietal regions and bottom-up information flow from the frontoparietal regions to the supplementary cortex were observed in the subregions encoding for the opposing goal. We conclude that selective motor goal encoding and execution rely on goal-dependent differences in subregional recurrent information flow patterns across the long-range dorsal motor network areas that exhibit graded functional specialization. © 2018 Wiley Periodicals, Inc.

Early hemi-diaphragmatic plication following intraoperative phrenic nerve transection during complete AV canal repair

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Hamad Alowayshiq

2018-04-01

Full Text Available Unilateral diaphragmatic palsy reduces pulmonary function by about 25% in older children and usually it is well tolerated; however, it causes severe respiratory distress in infants and young children. Diaphragmatic plication performed later than 10 days after cardiac surgery for patients under 1 year of age was associated with higher incidence of pneumonia and mortality. The management of the diaphragmatic paralysis due to phrenic nerve injury aiming mainly to preserve the respiratory function. Until now, the optimal management of diaphragmatic palsy in children who have undergone cardiac surgery remains controversial and consists of prolonged ventilation or diaphragmatic plication. In our case, many factors supported early diaphragmatic plication, the age of the patient, post-operative AV canal repair with severe pulmonary hypertension, and clear transection of the left phrenic nerve diagnosed intraoperatively.

Reduced phrenic motoneuron recruitment during sustained inspiratory threshold loading compared to single-breath loading: a twitch interpolation study

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Mathieu Raux

2016-11-01

Full Text Available In humans, inspiratory constraints engage cortical networks involving the supplementary motor area. Functional magnetic resonance imaging (fMRI shows that the spread and intensity of the corresponding respiratory-related cortical activation dramatically decrease when a discrete load becomes sustained. This has been interpreted as reflecting motor cortical reorganisation and automatisation, but could proceed from sensory and/or affective habituation. To corroborate the existence of motor reorganisation between single-breath and sustained inspiratory loading (namely changes in motor neurones recruitment, we conducted a diaphragm twitch interpolation study based on the hypothesis that motor reorganisation should result in changes in the twitch interpolation slope. Fourteen healthy subjects (age: 21 – 40 years were studied. Bilateral phrenic stimulation was delivered at rest, upon prepared and targeted voluntary inspiratory efforts (vol, upon unprepared inspiratory efforts against a single-breath inspiratory threshold load (single-breath, and upon sustained inspiratory efforts against the same type of load (continuous. The slope of the relationship between diaphragm twitch transdiaphragmatic pressure and the underlying transdiaphragmatic pressure was –1.1 ± 0.2 during vol, –1.5 ± 0.7 during single-breath, and -0.6 ± 0.4 during continuous (all slopes expressed in percent of baseline.percent of baseline-1 all comparisons significant at the 5% level. The contribution of the diaphragm to inspiration, as assessed by the gastric pressure to transdiaphragmatic pressure ratio, was 31 ± 17 % during vol, 22 ± 16 % during single-breath (p=0.13, and 19 ± 9 % during continuous (p = 0.0015 vs. vol. This study shows that the relationship between the amplitude of the transdiaphragmatic pressure produced by a diaphragm twitch and its counterpart produced by the underlying diaphragm contraction is not unequivocal. If twitch interpolation is interpreted as

Distribution of serotonin 2A and 2C receptor mRNA expression in the cervical ventral horn and phrenic motoneurons following spinal cord hemisection.

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Basura, G J; Zhou, S Y; Walker, P D; Goshgarian, H G

2001-06-01

Cervical spinal cord injury leads to a disruption of bulbospinal innervation from medullary respiratory centers to phrenic motoneurons. Animal models utilizing cervical hemisection result in inhibition of ipsilateral phrenic nerve activity, leading to paralysis of the hemidiaphragm. We have previously demonstrated a role for serotonin (5-HT) as one potential modulator of respiratory recovery following cervical hemisection, a mechanism that likely occurs via 5-HT2A and/or 5-HT2C receptors. The present study was designed to specifically examine if 5-HT2A and/or 5-HT2C receptors are colocalized with phrenic motoneurons in both intact and spinal-hemisected rats. Adult female rats (250-350 g; n = 6 per group) received a left cervical (C2) hemisection and were injected with the fluorescent retrograde neuronal tracer Fluorogold into the left hemidiaphragm. Twenty-four hours later, animals were killed and spinal cords processed for in situ hybridization and immunohistochemistry. Using (35)S-labeled cRNA probes, cervical spinal cords were probed for 5-HT2A and 5-HT2C receptor mRNA expression and double-labeled using an antibody to Fluorogold to detect phrenic motoneurons. Expression of both 5-HT2A and 5-HT2C receptor mRNA was detected in motoneurons of the cervical ventral horn. Despite positive expression of both 5-HT2A and 5-HT2C receptor mRNA-hybridization signal over phrenic motoneurons, only 5-HT2A silver grains achieved a signal-to-noise ratio representative of colocalization. 5-HT2A mRNA levels in identified phrenic motoneurons were not significantly altered following cervical hemisection compared to sham-operated controls. Selective colocalization of 5-HT2A receptor mRNA with phrenic motoneurons may have implications for recently observed 5-HT2A receptor-mediated regulation of respiratory activity and/or recovery in both intact and injury-compromised states. Copyright 2001 Academic Press.

Long-Lasting Cranial Nerve III Palsy as a Presenting Feature of Chronic Inflammatory Demyelinating Polyneuropathy

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Rossella Spataro

2015-01-01

Full Text Available We describe a patient with chronic inflammatory demyelinating polyneuropathy (CIDP in which an adduction deficit and ptosis in the left eye presented several years before the polyneuropathy. A 52-year-old man presented with a 14-year history of unremitting diplopia, adduction deficit, and ptosis in the left eye. At the age of 45 a mild bilateral foot drop and impaired sensation in the four limbs appeared, with these symptoms showing a progressive course. The diagnostic workup included EMG/ENG which demonstrated reduced conduction velocity with bilateral and symmetrical sensory and motor involvement. Cerebrospinal fluid studies revealed a cytoalbuminologic dissociation. A prolonged treatment with corticosteroids allowed a significant improvement of the limb weakness. Diplopia and ptosis remained unchanged. This unusual form of CIDP presented as a long-lasting isolated cranial nerve palsy. A diagnostic workup for CIDP should therefore be performed in those patients in which an isolated and unremitting cranial nerve palsy cannot be explained by common causes.

Ramification and distribution of the phrenic nerves in diaphragm of horses

Directory of Open Access Journals (Sweden)

Wilson Santiago

1990-12-01

Full Text Available The phrenic nerve distribution in 50 diaphragmas from mixed breeding adult horses (25 males and 25 females obtained from a slaughter house ("Avante", located in Araguari, State of Minas Gerais, was studied. The results indicated the following characteristics: 1 the ventral branch and laterodorsal trunk were extended 42 times (84% to the right side, 5 times (10% to the left, while the dorsal and the lateroventral trunk were 40 times (80% to the left and 2 times (4% to the right. The common origin of the dorsal, lateral and ventral branch were 6 times (12% to the right and 5 times (10% to the left. 2 The right and left bifurcation of the phrenic nerve were symmetrically arranged in: laterodorsal trunk and ventral branch 9 times (18%; lateroventral trunk and dorsal branch 5 times (10% and simultaneously in lateral and ventral dorsal branches 2 times (4%. 3 The right and left dorsal branches of the phrenic nerve were always distributed on the limbar portion (medial and lateral pillar in relation to their origins. The distribution of the nervous fillets from the right dorsal branch to the dorsal foliolo was: one fillet 10 times (20% and 2 fillets 1 time (2% respectively. To the tendinous center one fillet (2% was observed. From the left dorsal branch in 50 times (100% there was one fillet going to the right medial pillar. In relation to the left dorsal foliolo there was: one fillet 3 times (6% and 2 fillets 3 times (6% and in relation to the tendinous center there was: one fillet 3 times (6%; 2 fillets 2 times (4% and 4 fillets just once (2%. 4 From the right and left lateral branches of the phrenic nerve in all observations (100% there were fillets going to the lateral dorsal region in both sides. The distribution of the emerging fibers from the right lateral branch to the do sal foliolo was 1  fillet 6 times (12%; 2 fillets 3 times (6%; 3 fillets 1 time (2% and to the right lateral pillar 1 fillet 2 times (4%. The distribution of the emerging

Effective utilization period of long-lasting insecticide treated nets ...

African Journals Online (AJOL)

The study was conducted to evaluate the bioefficacy of long-lasting insecticide treated nets (LLITNs) (PermaNet®2.0) over time and the species composition of Anopheles mosquitoes around Bahir Dar. The space spray collection method was used to determine the species composition of indoor resting Anopheles ...

Dual Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varix Draining into the Left Adrenal Vein and Left Inferior Phrenic Vein

International Nuclear Information System (INIS)

Nishida, Norifumi; Ninoi, Teruhisa; Kitayama, Toshiaki; Yamamoto, Akira; Sakai, Yukimasa; Sato, Kimihiko; Hamuro, Masao; Nakamura, Kenji; Inoue, Yuichi; Yamada, Ryusaku

2004-01-01

A 66-year-old woman with a gastric varix, draining into a dilated left adrenal vein and a left inferior phrenic vein, was treated with dual balloon-occluded retrograde transvenous obliteration (B-RTO). Under balloon occlusion of the left adrenal vein and the left inferior phrenic vein, retrograde injection of a sclerosant (5% ethanolamine oleate) into the gastric varix was performed. Two weeks later, disappearance of flow in the gastric varix was confirmed on endoscopic ultrasound examination

Long-range cargo transport on crowded microtubules: The motor jamming mechanism

Science.gov (United States)

Rossi, Lucas W.; Radtke, Paul K.; Goldman, Carla

2014-05-01

The hopping model for cargo transport by molecular motors introduced in Goldman and Sena (2009), Goldman (2010) is extended here in order to incorporate the movement of cargo-motor complexes (C-MC). Hopping processes in this context express the possibility for cargo to be exchanged between neighboring motors at a microtubule where the transport takes place. Jamming of motors is essential for cargos to execute long-range movement in this way. Results from computer simulations accompanied by a mean-field analysis of the extended model confirm our previous analytical results and suggests that an interplay between cargo hopping and the movement of the C-MC’s would control the efficiency of cargo transfer and cargo delivery in these model systems.

Preventing phrenic nerve stimulation by a patch insulation in an intact swine heart model.

Directory of Open Access Journals (Sweden)

Jin-Long Huang

Full Text Available Phrenic nerve stimulation (PNS could be prevented by a silastic patch over the epicardial lead. We studied the effects in preventing PNS by placing a silastic patch directly over an epicardial lead or placing a graft around the phrenic nerve (PN.Fourteen Lanyu swine were enrolled. A bipolar lead was placed epicardially on the left ventricle (LV inferior to the PN. An implantable cardioverter-defibrillator (ICD lead was placed into the right ventricle (RV. The maximal influential distance (MID was measured under 3 pacing configurations to express the influential electrical field on the PN. The threshold of the LV and PN were evaluated epicardially. Then, PTFE patches of different sizes (10×10 mm, 20×20 mm and 30×30 mm were placed between the LV lead and PN to study the rise in PN threshold in 7 swine. On the other hand, the PN were surrounded by a PTFE graft of different lengths (10 mm, 20 mm, and 30 mm in the remaining 7 swine. LV-bipolar pacing showed the shortest MID when compared to the other 2 unipolar pacing configurations at pacing voltage of 10 V. The patch was most effective in preventing PNS during LV-bipolar pacing. PNS was prevented under all circumstances with a larger PTFE patch (30×30 mm or long graft (30 mm.PNS was avoided by placing a PTFE patch over the LV lead or a graft around the PN despite pacing configurations. Hence if PNS persisted during CRT implantation, a PTFE patch on the LV lead or a graft around the PN could be considered.

Variations in the origin of inferior phrenic arteries and their relationship to celiac axis variations on CT angiography

Energy Technology Data Exchange (ETDEWEB)

Aslaner, Ramazan; Pekcevik, Yeliz; Sahin, Hilal [Dept. of Radiology, Tepecik Training and Research Hospital, Izmir (Turkmenistan); Toka, Onur [Dept. of Statistics, Hacettepe University, Ankara (Turkmenistan)

2017-04-15

Knowing the origin of the inferior phrenic artery (IPA) is important prior to surgical interventions and interventional radiological procedures related to IPA. We aimed to identify variations in the origin of IPA and to investigate the relationship between the origin of IPA and celiac axis variations using computed tomography angiography (CTA). The CTA images of 1000 patients (737 male and 263 female, the mean age 60, range 18–94 years) were reviewed in an analysis of IPA and celiac axis variations. The origin of IPA was divided into two groups, those originating as a common trunk and those originating independently without a truncus. The relationship between the origin of IPA and celiac axis variation was analyzed using Pearson's chi-square test. Both IPAs originated from a common trunk in 295 (29.5%) patients. From which the majority of the common trunk originated from the aorta. Contrastingly, the inferior phrenic arteries originated from different origins in 705 (70.5%) patients. The majority of the right inferior phrenic artery (RIPA) and the left inferior phrenic artery (LIPA) originated independently from the celiac axis. Variation in the celiac axis were detected in 110 (11%) patients. The origin of IPA was found to be significantly different in the presence of celiac axis variation. The majority of IPA originated from the aorta in patients with a common IPA trunk, while the majority of RIPA and LIPA originating from the celiac axis in patients without a common IPA trunk. Thus, the origin of IPA may widely differ in the presence of celiac axis variation.

Variations in the origin of inferior phrenic arteries and their relationship to celiac axis variations on CT angiography

International Nuclear Information System (INIS)

Aslaner, Ramazan; Pekcevik, Yeliz; Sahin, Hilal; Toka, Onur

2017-01-01

Knowing the origin of the inferior phrenic artery (IPA) is important prior to surgical interventions and interventional radiological procedures related to IPA. We aimed to identify variations in the origin of IPA and to investigate the relationship between the origin of IPA and celiac axis variations using computed tomography angiography (CTA). The CTA images of 1000 patients (737 male and 263 female, the mean age 60, range 18–94 years) were reviewed in an analysis of IPA and celiac axis variations. The origin of IPA was divided into two groups, those originating as a common trunk and those originating independently without a truncus. The relationship between the origin of IPA and celiac axis variation was analyzed using Pearson's chi-square test. Both IPAs originated from a common trunk in 295 (29.5%) patients. From which the majority of the common trunk originated from the aorta. Contrastingly, the inferior phrenic arteries originated from different origins in 705 (70.5%) patients. The majority of the right inferior phrenic artery (RIPA) and the left inferior phrenic artery (LIPA) originated independently from the celiac axis. Variation in the celiac axis were detected in 110 (11%) patients. The origin of IPA was found to be significantly different in the presence of celiac axis variation. The majority of IPA originated from the aorta in patients with a common IPA trunk, while the majority of RIPA and LIPA originating from the celiac axis in patients without a common IPA trunk. Thus, the origin of IPA may widely differ in the presence of celiac axis variation

Variations in the Origin of Inferior Phrenic Arteries and Their Relationship to Celiac Axis Variations on CT Angiography.

Science.gov (United States)

Aslaner, Ramazan; Pekcevik, Yeliz; Sahin, Hilal; Toka, Onur

2017-01-01

Knowing the origin of the inferior phrenic artery (IPA) is important prior to surgical interventions and interventional radiological procedures related to IPA. We aimed to identify variations in the origin of IPA and to investigate the relationship between the origin of IPA and celiac axis variations using computed tomography angiography (CTA). The CTA images of 1000 patients (737 male and 263 female, the mean age 60, range 18-94 years) were reviewed in an analysis of IPA and celiac axis variations. The origin of IPA was divided into two groups, those originating as a common trunk and those originating independently without a truncus. The relationship between the origin of IPA and celiac axis variation was analyzed using Pearson's chi-square test. Both IPAs originated from a common trunk in 295 (29.5%) patients. From which the majority of the common trunk originated from the aorta. Contrastingly, the inferior phrenic arteries originated from different origins in 705 (70.5%) patients. The majority of the right inferior phrenic artery (RIPA) and the left inferior phrenic artery (LIPA) originated independently from the celiac axis. Variation in the celiac axis were detected in 110 (11%) patients. The origin of IPA was found to be significantly different in the presence of celiac axis variation. The majority of IPA originated from the aorta in patients with a common IPA trunk, while the majority of RIPA and LIPA originating from the celiac axis in patients without a common IPA trunk. Thus, the origin of IPA may widely differ in the presence of celiac axis variation.

Balloon-occluded retrograde transvenous obliteration of gastric varix draining via the left inferior phrenic vein into the left hepatic vein

International Nuclear Information System (INIS)

Ibukuro, Kenji; Mori, Koichi; Tsukiyama, Toshitaka; Inoue, Yoshihiro; Iwamoto, Yukako; Tagawa, Kazumi

1999-01-01

We encountered a patient with gastric varix draining not via the usual left suprarenal vein but via the left inferior phrenic vein joining the left hepatic vein. Transfemoral balloon-occluded retrograde transvenous obliteration (BRTO) of the varix was performed under balloon occlusion of the left inferior phrenic vein via the left hepatic vein and retrograde injection of the sclerosing agent (5% of ethanolamine oleate) into the gastric varix. Disappearance of the gastric varix was confirmed on endoscopic examination 2 months later.

Risk of long-lasting negative cognitive consequences after electroconvulsive therapy

DEFF Research Database (Denmark)

Svendsen, Anne Marie; Miskowiak, Kamilla; Vinberg, Maj

2013-01-01

This case study describes a patient who had a unipolar depression and experienced long-lasting cognitive problems after electroconvulsive therapy (ECT). Neuropsychological testing revealed lower scores on measures of learning, memory and sustained attention. These results stress the importance...

SELECTIVE LARYNGEAL ABDUCTOR REINNERVATION IN CATS USING A PHRENIC-NERVE TRANSFER AND ORG-2766

NARCIS (Netherlands)

MAHIEU, HF; VANLITHBIJL, JT; GROENHOUT, C; TONNAER, JADM; DEWILDE, P

Reinnervation of the recurrent laryngeal nerve following nerve injury often leads to laryngeal synkinesis. Selective reinnervation of adductor and abductor muscles might be able to avoid synkinesis. This study presents the results of selective abductor reinnervation in cats, using a phrenic nerve

Evaluating the evidence: is phrenic nerve stimulation a safe and effective tool for decreasing ventilator dependence in patients with high cervical spinal cord injuries and central hypoventilation?

Science.gov (United States)

Sieg, Emily P; Payne, Russell A; Hazard, Sprague; Rizk, Elias

2016-06-01

Case reports, case series and case control studies have looked at the use of phrenic nerve stimulators in the setting of high spinal cord injuries and central hypoventilation syndromes dating back to the 1980s. We evaluated the evidence related to this topic by performing a systematic review of the published literature. Search terms "phrenic nerve stimulation," "phrenic nerve and spinal cord injury," and "phrenic nerve and central hypoventilation" were entered into standard search engines in a systematic fashion. Articles were reviewed by two study authors and graded independently for class of evidence according to published guidelines. The published evidence was reviewed, and the overall body of evidence was evaluated using the grading of recommendations, assesment, development and evaluations (GRADE) criteria Balshem et al. (J Clin Epidemiol 64:401-406, 2011). Our initial search yielded 420 articles. There were no class I, II, or III studies. There were 18 relevant class IV articles. There were no discrepancies among article ratings (i.e., kappa = 1). A meta-analysis could not be performed due to the low quality of the available evidence. The overall quality of the body of evidence was evaluated using GRADE criteria and fell within the "very poor" category. The quality of the published literature for phrenic nerve stimulation is poor. Our review of the literature suggests that phrenic nerve stimulation is a safe and effective option for decreasing ventilator dependence in high spinal cord injuries and central hypoventilation; however, we are left with critical questions that provide crucial directions for future studies.

Spatiotemporal characteristics of motor actions by blind long jump athletes.

Science.gov (United States)

Torralba, Miguel Angel; Padullés, José María; Losada, Jose Luis; López, Jose Luis

2017-01-01

Blind people depend on spatial and temporal representations to perform activities of daily living and compete in sport. The aim of this study is to determine the spatiotemporal characteristics of long jumps performed by blind athletes and compare findings with those reported for sighted athletes. We analysed a sample of 12 male athletes competing in the F11 Long Jump Finals at the Paralympic Games in London 2012. Performances were recorded using four high-speed cameras, and speeds were measured using a radar speed gun. The images were processed using validated image analysis software. The long jump run-up is shorter in blind athletes than in sighted athletes. We observed statistically significant differences for body centre of mass velocity and an increase in speed over the last three strides prior to take-off, contrasting with reports for sighted athletes and athletes with less severe visual impairment, who maintain or reduce their speed during the last stride. Stride length for the last three strides was the only spatial characteristic that was not significantly associated with effective jump distance. Blind long jumpers extend rather than shorten their last stride. Contact time with the take-off board is longer than that reported for sighted athletes. The actions of blind long jumpers, unlike those without disabilities, do not vary their leg actions during the final runway approach for optimal placement on the take-off board.

Ultrasound-Guided Interscalene Catheter Complicated by Persistent Phrenic Nerve Palsy

Directory of Open Access Journals (Sweden)

Andrew T. Koogler

2018-01-01

Full Text Available A 76-year-old male presented for reverse total shoulder arthroplasty (TSA in the beach chair position. A preoperative interscalene nerve catheter was placed under direct ultrasound-guidance utilizing a posterior in-plane approach. On POD 2, the catheter was removed. Three weeks postoperatively, the patient reported worsening dyspnea with a subsequent chest X-ray demonstrating an elevated right hemidiaphragm. Pulmonary function testing revealed worsening deficit from presurgical values consistent with phrenic nerve palsy. The patient decided to continue conservative management and declined further invasive testing or treatment. He was followed for one year postoperatively with moderate improvement of his exertional dyspnea over that period of time. The close proximity of the phrenic nerve to the brachial plexus in combination with its frequent anatomical variation can lead to unintentional mechanical trauma, intraneural injection, or chemical injury during performance of ISB. The only previously identified risk factor for PPNP is cervical degenerative disc disease. Although PPNP has been reported following TSA in the beach chair position without the presence of a nerve block, it is typically presumed as a complication of the interscalene block. Previously published case reports and case series of PPNP complicating ISBs all describe nerve blocks performed with either paresthesia technique or localization with nerve stimulation. We report a case of a patient experiencing PPNP following an ultrasound-guided placement of an interscalene nerve catheter.

Properties of 13HMF steel welded joints after long-lasting service

International Nuclear Information System (INIS)

Zeman, M.

2002-01-01

Results are presented of research conducted on the 13HMF steel in the as-received condition after long-lasting service over 100000 hours. Simulation tests have been performed by means of modern research methods. The influence of thermal cycles on the microstructure (continuous cooling TTT diagrams), plastic properties (notch toughness and hardness) of simulated heat affected zones and reheat cracking resistance has been evaluated by using the thermal and strain cycle simulator. Susceptibility to thermal fatigue has been determined, the creep strength estimated and welding heat input was given, as well as the post weld heat treatment conditions of the 13HMF steel after service. properties of the welded joints made of 13HMF steel after long-lasting service are given. (author)

Long-Stroke Nanopositioning Stage Driven by Piezoelectric Motor

Directory of Open Access Journals (Sweden)

Yong Wang

2014-01-01

Full Text Available This paper reported a biaxial nanopositioning stage single-driven by piezoelectric motor. The employed piezoelectric motor can perform two different driving modes, namely, AC drive mode to drive in long-stroke and at high-speed and DC scanning mode with the high-resolution of several nanometers, which satisfies the requirements of both long-stroke and nanoresolution. To compensate for the effects of the variable friction force and some unpredictable disturbances, a novel backward error compensation (BEC positioning control method integrated of the two driving modes and a double closed-loop PID controller system are proposed to obtain a high-accuracy positional motion. The experiment results demonstrate that the nanopositioning stage with large travel range of 300 mm × 300 mm has a fine speed characteristic and resolution is 5 nm. In the experiments of different travels up to 15 mm, calibrated by a commercial laser vibrometer, the positioning accuracy is proved within 55 nm in x-axis and 40 nm in y-axis with standard deviation less than 40 nm in x-axis and 30 nm in y-axis and the final position locking can be limited to 10 nm, meeting the requirements of micromanipulation technology.

miR-191 and miR-135 are required for long-lasting spine remodelling associated with synaptic long-term depression

Science.gov (United States)

Hu, Zhonghua; Yu, Danni; Gu, Qin-Hua; Yang, Yanqin; Tu, Kang; Zhu, Jun; Li, Zheng

2014-02-01

Activity-dependent modification of dendritic spines, subcellular compartments accommodating postsynaptic specializations in the brain, is an important cellular mechanism for brain development, cognition and synaptic pathology of brain disorders. NMDA receptor-dependent long-term depression (NMDAR-LTD), a prototypic form of synaptic plasticity, is accompanied by prolonged remodelling of spines. The mechanisms underlying long-lasting spine remodelling in NMDAR-LTD, however, are largely unclear. Here we show that LTD induction causes global changes in miRNA transcriptomes affecting many cellular activities. Specifically, we show that expression changes of miR-191 and miR-135 are required for maintenance but not induction of spine restructuring. Moreover, we find that actin depolymerization and AMPA receptor exocytosis are regulated for extended periods of time by miRNAs to support long-lasting spine plasticity. These findings reveal a miRNA-mediated mechanism and a role for AMPA receptor exocytosis in long-lasting spine plasticity, and identify a number of candidate miRNAs involved in LTD.

Long-lasting effects of perinatal asphyxia on exploration, memory and incentive downshift.

Science.gov (United States)

Galeano, Pablo; Blanco Calvo, Eduardo; Madureira de Oliveira, Diêgo; Cuenya, Lucas; Kamenetzky, Giselle Vanesa; Mustaca, Alba Elisabeth; Barreto, George Emilio; Giraldez-Alvarez, Lisandro Diego; Milei, José; Capani, Francisco

2011-10-01

Perinatal asphyxia remains as one of the most important causes of death and disability in children, without an effective treatment. Moreover, little is known about the long-lasting behavioral consequences of asphyxia at birth. Therefore, the main aim of the present study was to investigate the motor, emotional and cognitive functions of adult asphyctic rats. Experimental subjects consisted of rats born vaginally (CTL), by cesarean section (C+), or by cesarean section following 19 min of asphyxia (PA). At three months of age, animals were examined in a behavioral test battery including elevated plus maze, open field, Morris water maze, and an incentive downshift procedure. Results indicated that groups did not differ in anxiety-related behaviors, although a large variability was observed in the asphyctic group and therefore, the results are not completely conclusive. In addition, PA and C+ rats showed a deficit in exploration of new environments, but to a much lesser extent in the latter group. Spatial reference and working memory impairments were also found in PA rats. Finally, when animals were downshifted from a 32% to a 4% sucrose solution, an attenuated suppression of consummatory behavior was observed in PA rats. These results confirmed and extended those reported previously about the behavioral alterations associated with acute asphyxia around birth. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

Spatiotemporal characteristics of motor actions by blind long jump athletes

Science.gov (United States)

Torralba, Miguel Angel; Padullés, José María; Losada, Jose Luis; López, Jose Luis

2017-01-01

Background Blind people depend on spatial and temporal representations to perform activities of daily living and compete in sport. Objective The aim of this study is to determine the spatiotemporal characteristics of long jumps performed by blind athletes and compare findings with those reported for sighted athletes. Methods We analysed a sample of 12 male athletes competing in the F11 Long Jump Finals at the Paralympic Games in London 2012. Performances were recorded using four high-speed cameras, and speeds were measured using a radar speed gun. The images were processed using validated image analysis software. Results The long jump run-up is shorter in blind athletes than in sighted athletes. We observed statistically significant differences for body centre of mass velocity and an increase in speed over the last three strides prior to take-off, contrasting with reports for sighted athletes and athletes with less severe visual impairment, who maintain or reduce their speed during the last stride. Stride length for the last three strides was the only spatial characteristic that was not significantly associated with effective jump distance. Blind long jumpers extend rather than shorten their last stride. Contact time with the take-off board is longer than that reported for sighted athletes. Conclusion The actions of blind long jumpers, unlike those without disabilities, do not vary their leg actions during the final runway approach for optimal placement on the take-off board. PMID:29018542

Long-lasting changes in brain activation induced by a single REAC technology pulse in Wi-Fi bands. Randomized double-blind fMRI qualitative study.

Science.gov (United States)

Rinaldi, Salvatore; Mura, Marco; Castagna, Alessandro; Fontani, Vania

2014-07-11

The aim of this randomized double-blind study was to evaluate in healthy adult subjects, with functional magnetic resonance imaging (fMRI), long lasting changes in brain activation patterns following administration of a single, 250 milliseconds pulse emitted with radio-electric asymmetric conveyer (REAC) technology in the Wi-Fi bands. The REAC impulse was not administered during the scan, but after this, according to a protocol that has previously been demonstrated to be effective in improving motor control and postural balance, in healthy subjects and patients. The study was conducted on 33 healthy volunteers, performed with a 1.5 T unit while operating a motor block task involving cyclical and alternating flexion and extension of one leg. Subsequently subjects were randomly divided into a treatment and a sham treatment control group. Repeated fMRI examinations were performed following the administration of the REAC pulse or sham treatment. The Treated group showed cerebellar and ponto-mesencephalic activation components that disappeared in the second scan, while these activation components persisted in the Sham group. This study shows that a very weak signal, such as 250 milliseconds Wi-Fi pulse, administered with REAC technology, could lead to lasting effects on brain activity modification.

Long-term performance of motor-operated valves

Energy Technology Data Exchange (ETDEWEB)

Scarbrough, T.G.

1996-12-01

The U.S. Nuclear Regulatory Commission (NRC) requires that motor-operated valves (MOVs) important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Despite these requirements, operating experience and research revealed problems with the performance of MOVs in operating nuclear power plants. In response to the concerns about MOV performance, the NRC issued Generic Letter (GL) 89-10, {open_quotes}Safety-Related Motor-Operated Valve Testing and Surveillance,{close_quotes} and its supplements. Most licensees have completed the aspects of their GL 89-10 programs associated with the review of MOV design bases, verification of MOV switch settings initially, testing of MOVs under design-basis conditions where practicable, and improvement of evaluations of MOV failures and necessary corrective action. Licensees are establishing processes to ensure that the long-term aspects of their MOV programs, such as periodic verification of MOV capability and the trending of MOV problems, are maintained. The NRC staff is developing a generic letter to address periodic verification of MOV design-basis capability.

Long-term performance of motor-operated valves

International Nuclear Information System (INIS)

Scarbrough, T.G.

1996-01-01

The U.S. Nuclear Regulatory Commission (NRC) requires that motor-operated valves (MOVs) important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Despite these requirements, operating experience and research revealed problems with the performance of MOVs in operating nuclear power plants. In response to the concerns about MOV performance, the NRC issued Generic Letter (GL) 89-10, open-quotes Safety-Related Motor-Operated Valve Testing and Surveillance,close quotes and its supplements. Most licensees have completed the aspects of their GL 89-10 programs associated with the review of MOV design bases, verification of MOV switch settings initially, testing of MOVs under design-basis conditions where practicable, and improvement of evaluations of MOV failures and necessary corrective action. Licensees are establishing processes to ensure that the long-term aspects of their MOV programs, such as periodic verification of MOV capability and the trending of MOV problems, are maintained. The NRC staff is developing a generic letter to address periodic verification of MOV design-basis capability

Phrenic nerve block with ultrasound-guidance for treatment of hiccups: a case report

Directory of Open Access Journals (Sweden)

Pyylampi Ville

2011-10-01

Full Text Available Abstract Introduction Persistent hiccups can be more than a simple and short-lived nuisance and therefore sometimes call for serious consideration. Hiccupping episodes that last only a few minutes may be annoying, but persistent hiccups may initiate many major complications. Case presentation A 72-year-old Caucasian man with spinal stenosis presented for L4-5 laminectomy under spinal anesthesia. The surgery and anesthesia, as well as the perioperative period, passed without any incident, except for persistent postoperative hiccups not responding to conservative and pharmacological treatment. Hiccups resulted in a prolonged hospital stay as they lasted until the seventh postoperative day. On that day, a right-sided ultrasound-guided phrenic nerve block with 5 ml of bupivacaine 5 mg/ml with epinephrine was performed successfully with a single-injection technique. Ten minutes after the procedure the hiccups vanished and a partial sensomotoric block of his right shoulder developed. No adverse effect occurred; our patient could be discharged on the same day and the hiccups did not return. Conclusion Ultrasound provides us with non-invasive information regarding anatomy and allows anesthesiologists to visualize needle insertion, to identify the exact location of the injected solution and to avoid such structures as arteries or veins. As such, this method should be actively utilized. In cases where both pharmacological and non-pharmacological treatments prove to be ineffective when treating persistent hiccups, a single-shot ultrasound-guided technique should be considered before the patient becomes exhausted.

Demonstration of the right inferior phrenic artery by using multislice helical CT

International Nuclear Information System (INIS)

Zhao Shaohong; Liu Xin; Cai Zulong; Zhao Hong; Yang Li

2006-01-01

Objective: To demonstrate the origin of the right inferior phrenic artery (RIPA) in normal and hepatocellular carcinoma (HCC) patients and provide valuable anatomical information for angiographers before and after transcatheter arterial chemoembolization (TACE). Methods: Four hundred and forty consecutive patients including 133 HCC cases who had biphase abdominal CT were assessed in this study. The routine abdominal enhanced CT scan (GE, LightSpeed16) was performed with 120 kV, 200-240 mAs, 10 mm collimation, 1.375 pitch, and 10 mm reconstruction interval at 22-25 seconds for arterial phase triggered by timing bolus, 60 seconds for portal venous phase after injection of 100 ml contrast material (300 mg I/ml) at a rate of 3.5 ml/s. Multiplanar reconstruction (MPR) and maximum intensity projection (MIP) images were generated using 1.25 mm images reconstructed with 1 mm interval in arterial phase and reviewed by two radiologists. An enhanced artery medial-posterior to the IVC, originated from aorta or its branches to the diaphragmatic dome was interpreted as the RIPA. Results: The RIPA was showed in all 440 patients (100%). Among 218 (49.5%) RIPAs originated from the aorta, 140 were from the fight side of the aorta, 22 from the left side of the aorta, 56 from the anterior wall of the aorta, 36 RIPAs had the same origin with the left inferior phrenic artery. Among 138 (31.4%) RIPAs from the celiac artery, 10 RIPAs had the same origin with the left gastric artery, and 33 RIPAs had the same origin with the left inferior phrenic artery. 78 (17.7%) were from the fight renal artery, 6 (1.4%) were from the left gastric artery (the left gastric artery from aorta). The dilatation of the RIPA was demonstrated in 16 of 133 hepatocellular carcinoma patients. Conclusion: Multislice helical CT could demonstrate the origin of the RIPA in arterial phase and provide useful anatomical information for angiographer before and after TACE. (authors)

Efficacy of topical mosquito repellent (picaridin) plus long-lasting insecticidal nets versus long-lasting insecticidal nets alone for control of malaria : A cluster randomised controlled trial

NARCIS (Netherlands)

Sluydts, V.; Durnez, L.; Heng, S.; Gryseels, C.; Canier, L.; Kim, S.; Van Roey, K.; Kerkhof, K.; Khim, N.; Mao, S.; Menard, D.; Coosemans, M.

2016-01-01

Background Although effective topical repellents provide personal protection against malaria, whether mass use of topical repellents in addition to long-lasting insecticidal nets can contribute to a further decline of malaria is not known, particularly in areas where outdoor transmission occurs. We

Catecholaminergic consolidation of motor cortical neuroplasticity in humans.

Science.gov (United States)

Nitsche, Michael A; Grundey, Jessica; Liebetanz, David; Lang, Nicolas; Tergau, Frithjof; Paulus, Walter

2004-11-01

Amphetamine, a catecholaminergic re-uptake-blocker, is able to improve neuroplastic mechanisms in humans. However, so far not much is known about the underlying physiological mechanisms. Here, we study the impact of amphetamine on NMDA receptor-dependent long-lasting excitability modifications in the human motor cortex elicited by weak transcranial direct current stimulation (tDCS). Amphetamine significantly enhanced and prolonged increases in anodal, tDCS-induced, long-lasting excitability. Under amphetamine premedication, anodal tDCS resulted in an enhancement of excitability which lasted until the morning after tDCS, compared to approximately 1 h in the placebo condition. Prolongation of the excitability enhancement was most pronounced for long-term effects; the duration of short-term excitability enhancement was only slightly increased. Since the additional application of the NMDA receptor antagonist dextromethorphane blocked any enhancement of tDCS-driven excitability under amphetamine, we conclude that amphetamine consolidates the tDCS-induced neuroplastic effects, but does not initiate them. The fact that propanolol, a beta-adrenergic antagonist, diminished the duration of the tDCS-generated after-effects suggests that adrenergic receptors play a certain role in the consolidation of NMDA receptor-dependent motor cortical excitability modifications in humans. This result may enable researchers to optimize neuroplastic processes in the human brain on the rational basis of purpose-designed pharmacological interventions.

Dual-tDCS Enhances Online Motor Skill Learning and Long-Term Retention in Chronic Stroke Patients

Science.gov (United States)

Lefebvre, S.; Laloux, P.; Peeters, A.; Desfontaines, P.; Jamart, J.; Vandermeeren, Y.

2013-01-01

Background: Since motor learning is a key component for stroke recovery, enhancing motor skill learning is a crucial challenge for neurorehabilitation. Transcranial direct current stimulation (tDCS) is a promising approach for improving motor learning. The aim of this trial was to test the hypothesis that dual-tDCS applied bilaterally over the primary motor cortices (M1) improves online motor skill learning with the paretic hand and its long-term retention. Methods: Eighteen chronic stroke patients participated in a randomized, cross-over, placebo-controlled, double bind trial. During separate sessions, dual-tDCS or sham dual-tDCS was applied over 30 min while stroke patients learned a complex visuomotor skill with the paretic hand: using a computer mouse to move a pointer along a complex circuit as quickly and accurately as possible. A learning index involving the evolution of the speed/accuracy trade-off was calculated. Performance of the motor skill was measured at baseline, after intervention and 1 week later. Results: After sham dual-tDCS, eight patients showed performance worsening. In contrast, dual-tDCS enhanced the amount and speed of online motor skill learning compared to sham (p dual-tDCS (n = 10) than after sham (n = 3). More importantly, 1 week later, online enhancement under dual-tDCS had translated into superior long-term retention (+44%) compared to sham (+4%). The improvement generalized to a new untrained circuit and to digital dexterity. Conclusion: A single-session of dual-tDCS, applied while stroke patients trained with the paretic hand significantly enhanced online motor skill learning both quantitatively and qualitatively, leading to successful long-term retention and generalization. The combination of motor skill learning and dual-tDCS is promising for improving post-stroke neurorehabilitation. PMID:23316151

Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

Directory of Open Access Journals (Sweden)

Wan-Tsun Tseng

2013-01-01

Full Text Available The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of operation, namely premature commutation, simultaneous commutation, and late commutation. Each type of operation has a different thrust drop which can be affected by several parameters such as jerk, running speed, motor section length, and vehicle data. This paper focuses on determining the thrust drop of the change-step mode. The study results of this paper can be used to improve the operation system of high-speed maglev trains.

Management of Pleural Space After Lung Resection by Cryoneuroablation of Phrenic Nerve: A Randomized Study.

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Pan, Xiao-Jie; Ou, De-Bin; Lin, Xing; Ye, Ming-Fang

2017-06-01

Residual air space problems after pulmonary lobectomy are an important concern in thoracic surgical practice, and various procedures have been applied to manage them. This study describes a novel technique using controllable paralysis of the diaphragm by localized freezing of the phrenic nerve, and assesses the effectiveness of this procedure to reduce air space after pulmonary lobectomy. In this prospective randomized study, 207 patients who underwent lobectomy or bilobectomy and systematic mediastinal node dissection in our department between January 2009 and November 2013 were randomly allocated to a cryoneuroablation group or a conventional group. Patients in the cryoneuroablation group (n = 104) received phrenic nerve cryoneuroablation after lung procedures, and patients in the conventional group (n = 103) did not receive cryoneuroablation after the procedure. Data regarding preoperative clinical and surgical characteristics in both groups were collected. Both groups were compared with regard to postoperative parameters such as total amount of pleural drainage, duration of chest tube placement, length of hospital stay, requirement for repeat chest drain insertion, prolonged air leak, and residual space. Perioperative lung function was also compared in both groups. Recovery of diaphragmatic movement in the cryoneuroablation group was checked by fluoroscopy on the 15th, 30th, and 60th day after surgery. There was no statistically significant difference in patient characteristics between the 2 groups; nor was there a difference in terms of hospital stay, new drain requirement, and incidence of empyema. In comparison with the conventional group, the cryoneuroablation group had less total drainage (1024 ± 562 vs 1520 ± 631 mL, P phrenic nerve offers a reasonable option for prevention of residual air space following major pulmonary resection.

MDCT Anatomic Assessment of Right Inferior Phrenic Artery Origin Related to Potential Supply to Hepatocellular Carcinoma and its Embolization

International Nuclear Information System (INIS)

Basile, Antonio; Tsetis, Dimitrios; Montineri, Arturo; Puleo, Stefano; Massa Saluzzo, Cesare; Runza, Giuseppe; Coppolino, Francesco; Ettorre, Giovanni Carlo; Patti, Maria Teresa

2008-01-01

Purpose. To prospectively assess the anatomic variation of the right inferior phrenic artery (RIPA) origin with multidetector computed tomography (MDCT) scans in relation to the technical and angiographic findings during transcatheter arterial embolization of hepatocellular carcinoma (HCC). Methods. Two hundred patients with hepatocellular carcinomas were examined with 16-section CT during the arterial phase. The anatomy of the inferior phrenic arteries was recorded, with particular reference to their origin. All patients with subcapsular HCC located at segments VII and VIII underwent arteriography of the RIPA with subsequent embolization if neoplastic supply was detected. Results. The RIPA origin was detected in all cases (sensitivity 100%), while the left inferior phrenic artery origin was detected in 187 cases (sensitivity 93.5%). RIPAs originated from the aorta (49%), celiac trunk (41%), right renal artery (5.5%), left gastric artery (4%), and proper hepatic artery (0.5%), with 13 types of combinations with the left IPA. Twenty-nine patients showed subcapsular HCCs in segments VII and VIII and all but one underwent RIPA selective angiography, followed by embolization in 7 cases. Conclusion. MDCT assesses well the anatomy of RIPAs, which is fundamental for planning subsequent cannulation and embolization of extrahepatic RIPA supply to HCC

Distributional learning has immediate and long-lasting effects.

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Escudero, Paola; Williams, Daniel

2014-11-01

Evidence of distributional learning, a statistical learning mechanism centered on relative frequency of exposure to different tokens, has mainly come from short-term learning and therefore does not ostensibly address the development of important learning processes. The present longitudinal study examines both short- and long-term effects of distributional learning of phonetic categories on non-native sound discrimination over a 12-month period. Two groups of listeners were exposed to a two-minute distribution of auditory stimuli in which the most frequently presented tokens either approximated or exaggerated the natural production of the speech sounds, whereas a control group listened to a piece of classical music for the same length of time. Discrimination by listeners in the two distribution groups improved immediately after the short exposure, replicating previous results. Crucially, this improvement was maintained after six and 12 months, demonstrating that distributional learning has long-lasting effects. Copyright © 2014 Elsevier B.V. All rights reserved.

Rehabilitation, Using Guided Cerebral Plasticity, of a Brachial Plexus Injury Treated with Intercostal and Phrenic Nerve Transfers.

Science.gov (United States)

Dahlin, Lars B; Andersson, Gert; Backman, Clas; Svensson, Hampus; Björkman, Anders

2017-01-01

Recovery after surgical reconstruction of a brachial plexus injury using nerve grafting and nerve transfer procedures is a function of peripheral nerve regeneration and cerebral reorganization. A 15-year-old boy, with traumatic avulsion of nerve roots C5-C7 and a non-rupture of C8-T1, was operated 3 weeks after the injury with nerve transfers: (a) terminal part of the accessory nerve to the suprascapular nerve, (b) the second and third intercostal nerves to the axillary nerve, and (c) the fourth to sixth intercostal nerves to the musculocutaneous nerve. A second operation-free contralateral gracilis muscle transfer directly innervated by the phrenic nerve-was done after 2 years due to insufficient recovery of the biceps muscle function. One year later, electromyography showed activation of the biceps muscle essentially with coughing through the intercostal nerves, and of the transferred gracilis muscle by deep breathing through the phrenic nerve. Voluntary flexion of the elbow elicited clear activity in the biceps/gracilis muscles with decreasing activity in intercostal muscles distal to the transferred intercostal nerves (i.e., corresponding to eighth intercostal), indicating cerebral plasticity, where neural control of elbow flexion is gradually separated from control of breathing. To restore voluntary elbow function after nerve transfers, the rehabilitation of patients operated with intercostal nerve transfers should concentrate on transferring coughing function, while patients with phrenic nerve transfers should focus on transferring deep breathing function.

Long-Term Experience with First-Generation Implantable Neurostimulation Device in Central Sleep Apnea Treatment.

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Fox, Henrik; Bitter, Thomas; Horstkotte, Dieter; Oldenburg, Olaf; Gutleben, Klaus-Jürgen

2017-05-01

Sleep-disordered breathing (SDB) and Cheyne-Stokes respiration (CSR) are associated with shorter survival in patients with heart failure. A novel treatment method for this patient group is unilateral phrenic nerve stimulation by the remedē® system (Respicardia Inc., Minnetonka, MN, USA), a transvenously implantable neurostimulation device, which has recently been studied in a large randomized, controlled trial. Previous literature has shown efficacy and safety of the treatment with this first-generation device, but hardly any data are available on long-term clinical parameters, the remedē® device's battery lifetime, device exchangeability, lead position stability, surgical accessibility, and manageability. We performed remedē® device replacements in consecutive patients for battery depletion, and documented clinical parameters, longevity, operation procedure, complications, and difficulties. All patients were on neurostimulation treatment by phrenic nerve neurostimulation when device replacement became necessary. Apnea-hypopnea index (from 45 ± 4/h to 9 ± 4/h), oxygen-desaturation index (from 35 ± 7/h to 7 ± 6/h), and time spent with oxygen saturation of ray documentation of stable lead positions in a long-term setting, no radiation or contrast dye usage was needed and no major complications occurred. In addition, clinical exercise capacity and sleepiness symptoms improved. Novel remedē® device shows sustained therapy efficacy and safety in terms of stable lead positions over 4 years. Long-term phrenic nerve neurostimulation therapy for central SDB/CSR appears feasible in a clinical routine setting. © 2017 Wiley Periodicals, Inc.

An enigmatic long-lasting gamma-ray burst not accompanied by a bright supernova.

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Della Valle, M; Chincarini, G; Panagia, N; Tagliaferri, G; Malesani, D; Testa, V; Fugazza, D; Campana, S; Covino, S; Mangano, V; Antonelli, L A; D'Avanzo, P; Hurley, K; Mirabel, I F; Pellizza, L J; Piranomonte, S; Stella, L

2006-12-21

Gamma-ray bursts (GRBs) are short, intense flashes of soft gamma-rays coming from the distant Universe. Long-duration GRBs (those lasting more than approximately 2 s) are believed to originate from the deaths of massive stars, mainly on the basis of a handful of solid associations between GRBs and supernovae. GRB 060614, one of the closest GRBs discovered, consisted of a 5-s hard spike followed by softer, brighter emission that lasted for approximately 100 s (refs 8, 9). Here we report deep optical observations of GRB 060614 showing no emerging supernova with absolute visual magnitude brighter than M(V) = -13.7. Any supernova associated with GRB 060614 was therefore at least 100 times fainter, at optical wavelengths, than the other supernovae associated with GRBs. This demonstrates that some long-lasting GRBs can either be associated with a very faint supernova or produced by different phenomena.

Drive equipment of the TRANSRAPID 06 with an iron bearing synchronous long stator motor

Energy Technology Data Exchange (ETDEWEB)

Parsch, C P; Ciessow, G

1981-01-01

For the testing of an application orientated Maglev the TRANSRAPID test center Emsland is being installed by the joint venture TRANSRAPID. The drive of the vehicle TRANSRAPID 06 is realized by an iron bearing synchronous long stator motor. A description is given of the principle of this drive, the output of traction motor and substation and of the dynamics of vehicle movement's calculations.

"Long life" DC brush motor for use on the Mars surveyor program

Science.gov (United States)

Braun, David; Noon, Don

1998-01-01

DC brush motors have several qualities which make them very attractive for space flight applications. Their mechanical commutation is simple and lightweight, requiring no external sensing and control in order to function properly. They are extremely efficient in converting electrical energy into mechanical energy. Efficiencies over 80% are not uncommon, resulting in high power throughput to weight ratios. However, the inherent unreliability and short life of sliding electrical contacts, especially in vacuum, have driven previous programs to utilize complex brushless DC or the less efficient stepper motors. The Mars Surveyor Program (MSP'98) and the Shuttle Radar Topography Mission (SRTM) have developed a reliable "long life" brush type DC motor for operation in low temperature, low pressure CO2 and N2, utilizing silver-graphite brushes. The original intent was to utilize this same motor for SRTM's space operation, but the results thus far have been unsatisfactory in vacuum. This paper describes the design, test, and results of this development.

Fascicular Phrenic Nerve Neurotization for Restoring Physiological Motion in a Congenital Diaphragmatic Hernia Reconstruction With a Reverse Innervated Latissimus Dorsi Muscle Flap.

Science.gov (United States)

Horta, Ricardo; Henriques-Coelho, Tiago; Costa, Joana; Estevão-Costa, José; Monteiro, Diana; Dias, Mariana; Braga, José; Silva, Alvaro; Azevedo, Inês; Amarante, José Manuel

2015-08-01

Congenital diaphragmatic hernia is a severe developmental anomaly characterized by the malformation of the diaphragm. An innervated reversed latissimus dorsi flap reconstruction for recurrent congenital diaphragmatic hernia has been described as an alternative to prosthetic patch repair to achieve pleuroperitoneal separation. However, there is very little supporting scientific data; therefore, there is no real basic understanding of the condition of the phrenic nerve in the absence of diaphragmatic muscle or even the neurotization options for restoring neodiaphragmatic muscle motion. We have reviewed the literature regarding phrenic nerve anatomy and neurotization options, and to our knowledge, this is the first time that the application of a fascicular repair is being described where the continuity of one remaining fascicle of the diaphragm has been preserved close to the phrenic nerve distal division. The procedure was undertaken in a 3 year-old boy, with the diagnosis of congenital large posteromedial diaphragmatic hernia and dependence of mechanical ventilation in consequence of severe bronchopulmonary dysplasia.The phrenic nerve divides itself into several terminal branches, usually three, at the diaphragm level, or just above it. This allows the selective coaptation of separate fascicular branches. In the case described, videofluoroscopy evaluation showed no evidence of paradoxical neodiaphragmatic motion, with synchronous contraction movements and intact pleura-peritoneal separation. The child is now asymptomatic and shows improvement of his previous restrictive pulmonary disease.We believe that fascicular repair can achieve some reinnervation of the flap without jeopardizing the potential of diaphragmatic function by contraction of reminiscent native diaphragm.

The Effects of Phrenic Nerve Degeneration by Axotomy and Crush on the Electrical Activities of Diaphragm Muscles of Rats.

Science.gov (United States)

Alkiş, Mehmet Eşref; Kavak, Servet; Sayır, Fuat; Him, Aydin

2016-03-01

The aim of this study was to investigate the effect of axotomy and crush-related degeneration on the electrical activities of diaphragm muscle strips of experimental rats. In the present study, twenty-one male Wistar-albino rats were used and divided into three groups. The animals in the first group were not crushed or axotomized and served as controls. Phrenic nerves of the rats in the second and third groups were crushed or axotomized in the diaphragm muscle. Resting membrane potential (RMP) was decreased significantly in both crush and axotomy of diaphragm muscle strips of experimental rats (p phrenic nerves may produce electrical activities in the diaphragm muscle of the rat by depolarization time and half-repolarization time prolonged in crush and axotomy rats.

Preventing long-lasting fear recovery using bilateral alternating sensory stimulation: A translational study.

Science.gov (United States)

Wurtz, H; El-Khoury-Malhame, M; Wilhelm, F H; Michael, T; Beetz, E M; Roques, J; Reynaud, E; Courtin, J; Khalfa, S; Herry, C

2016-05-03

Posttraumatic stress disorder (PTSD) is a highly debilitating and prevalent psychological disorder. It is characterized by highly distressing intrusive trauma memories that are partly explained by fear conditioning. Despite efficient therapeutic approaches, a subset of PTSD patients displays spontaneous recurrence of traumatic memories after successful treatment. The development of animal behavioral models mimicking the individual variability in treatment outcome for PTSD patients represent therefore an important challenge as it allows for the identification of predicting factors of resilience or susceptibility to relapse. However, to date, only few animal behavioral models of long-lasting fear recovery have been developed and their predictive validity has not been tested directly. The objectives of this study were twofold. First we aimed to develop a simple animal behavioral model of long-lasting fear recovery based on auditory cued fear conditioning and extinction learning, which recapitulates the heterogeneity of fear responses observed in PTSD patients after successful treatment. Second we aimed at testing the predictive validity of our behavioral model and used to this purpose a translational approach based (i) on the demonstration of the efficiency of Eye Movement Desensitization and Reprocessing (EMDR) therapy to reduce conditioned fear responses in PTSD patients and (ii) on the implementation in our behavioral model of an electrical bilateral alternating stimulation of the eyelid which mimics the core feature of EMDR. Our data indicate that electrical bilateral alternating stimulation of the eyelid during extinction learning alleviates long-lasting fear recovery of conditioned fear responses and dramatically reduces inter-individual variability. These results demonstrate the face and predictive validity of our animal behavioral model and provide an interesting tool to understand the neurobiological underpinnings of long-lasting fear recovery. Copyright �

How long do the short-term violent video game effects last?

Science.gov (United States)

Barlett, Christopher; Branch, Omar; Rodeheffer, Christopher; Harris, Richard

2009-01-01

How long do the effects of the initial short-term increase in aggression and physiological arousal last after violent video game play? Study 1 (N=91) had participants complete pre- and postvideo game measures of aggressive thoughts, aggressive feelings, and heart rate. Then, participants completed Time 3 measures after 4 min or 9 min of delay. Study 2 employed a similar procedure, but had participants (N=91) complete the hot sauce paradigm to assess aggressive behavior after a 0, 5, or 10 min delay. First, results indicated that aggressive feelings, aggressive thoughts, aggressive behavior, and heart rate initially increased after violent video game play. Second, results of the delay condition revealed that the increase in aggressive feelings and aggressive thoughts lasted less than 4 min, whereas heart rate and aggressive behavior lasted 4-9 min. Copyright 2009 Wiley-Liss, Inc.

Higher integrity of the motor and visual pathways in long-term video game players.

Science.gov (United States)

Zhang, Yang; Du, Guijin; Yang, Yongxin; Qin, Wen; Li, Xiaodong; Zhang, Quan

2015-01-01

Long term video game players (VGPs) exhibit superior visual and motor skills compared with non-video game control subjects (NVGCs). However, the neural basis underlying the enhanced behavioral performance remains largely unknown. To clarify this issue, the present study compared the whiter matter integrity within the corticospinal tracts (CST), the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the inferior fronto-occipital fasciculus (IFOF) between the VGPs and the NVGCs using diffusion tensor imaging. Compared with the NVGCs, voxel-wise comparisons revealed significantly higher fractional anisotropy (FA) values in some regions within the left CST, left SLF, bilateral ILF, and IFOF in VGPs. Furthermore, higher FA values in the left CST at the level of cerebral peduncle predicted a faster response in visual attention tasks. These results suggest that higher white matter integrity in the motor and higher-tier visual pathways is associated with long-term video game playing, which may contribute to the understanding on how video game play influences motor and visual performance.

Intermediate Leg SBLOCA - Long Lasting Pressure Transient

International Nuclear Information System (INIS)

Konjarek, D.; Bajs, T.; Vukovic, J.

2010-01-01

The basic phenomenology of Small Break Loss of Coolant Accident (SBLOCA) for PWR plant is described with focus on analysis of scenario in which reactor coolant pressure decreases below secondary system pressure. Best estimate light water reactor transient analysis code RELAP5/mod3.3 was used in calculation. Rather detailed model of the plant was used. The break occurs in intermediate leg on lowest elevation near pump suction. The size of the break is chosen to be small enough to cause cycling of safety valves (SVs) on steam generators (SGs) for some time, but, afterwards, it is large enough to remove decay heat through the break, causing cooling the secondary side. In this case of SBLOCA, when primary pressure decreases below secondary pressure, long lasting pressure transients with significant amplitude occur. Reasons for such behavior are explained.(author).

Reinnervation of bilateral posterior cricoarytenoid muscles using the left phrenic nerve in patients with bilateral vocal fold paralysis.

Directory of Open Access Journals (Sweden)

Meng Li

Full Text Available OBJECTIVE: To evaluate the feasibility, effectiveness, and safety of reinnervation of the bilateral posterior cricoarytenoid (PCA muscles using the left phrenic nerve in patients with bilateral vocal fold paralysis. METHODS: Forty-four patients with bilateral vocal fold paralysis who underwent reinnervation of the bilateral PCA muscles using the left phrenic nerve were enrolled in this study. Videostroboscopy, perceptual evaluation, acoustic analysis, maximum phonation time, pulmonary function testing, and laryngeal electromyography were performed preoperatively and postoperatively. Patients were followed-up for at least 1 year after surgery. RESULTS: Videostroboscopy showed that within 1 year after reinnervation, abductive movement could be observed in the left vocal folds of 87% of patients and the right vocal folds of 72% of patients. Abductive excursion on the left side was significantly larger than that on the right side (P 0.05. No patients developed immediate dyspnea after surgery, and the pulmonary function parameters recovered to normal reference value levels within 1 year. Postoperative laryngeal electromyography confirmed successful reinnervation of the bilateral PCA muscles. Eighty-seven percent of patients in this series were decannulated and did not show obvious dyspnea after physical activity. Those who were decannulated after subsequent arytenoidectomy were not included in calculating the success rate of decannulation. CONCLUSIONS: Reinnervation of the bilateral PCA muscles using the left phrenic nerve can restore inspiratory vocal fold abduction to a physiologically satisfactory extent while preserving phonatory function at the preoperative level without evident morbidity.

Reinnervation of Bilateral Posterior Cricoarytenoid Muscles Using the Left Phrenic Nerve in Patients with Bilateral Vocal Fold Paralysis

Science.gov (United States)

Zheng, Hongliang; Chen, Donghui; Zhu, Minhui; Wang, Wei; Liu, Fei; Zhang, Caiyun

2013-01-01

Objective To evaluate the feasibility, effectiveness, and safety of reinnervation of the bilateral posterior cricoarytenoid (PCA) muscles using the left phrenic nerve in patients with bilateral vocal fold paralysis. Methods Forty-four patients with bilateral vocal fold paralysis who underwent reinnervation of the bilateral PCA muscles using the left phrenic nerve were enrolled in this study. Videostroboscopy, perceptual evaluation, acoustic analysis, maximum phonation time, pulmonary function testing, and laryngeal electromyography were performed preoperatively and postoperatively. Patients were followed-up for at least 1 year after surgery. Results Videostroboscopy showed that within 1 year after reinnervation, abductive movement could be observed in the left vocal folds of 87% of patients and the right vocal folds of 72% of patients. Abductive excursion on the left side was significantly larger than that on the right side (P 0.05). No patients developed immediate dyspnea after surgery, and the pulmonary function parameters recovered to normal reference value levels within 1 year. Postoperative laryngeal electromyography confirmed successful reinnervation of the bilateral PCA muscles. Eighty-seven percent of patients in this series were decannulated and did not show obvious dyspnea after physical activity. Those who were decannulated after subsequent arytenoidectomy were not included in calculating the success rate of decannulation. Conclusions Reinnervation of the bilateral PCA muscles using the left phrenic nerve can restore inspiratory vocal fold abduction to a physiologically satisfactory extent while preserving phonatory function at the preoperative level without evident morbidity. PMID:24098581

Long-term progressive motor skill training enhances corticospinal excitability for the ipsilateral hemisphere and motor performance of the untrained hand

DEFF Research Database (Denmark)

Christiansen, Lasse; Larsen, Malte Nejst; Grey, Michael James

2017-01-01

It is well-established that unilateral motor practice can lead to increased performance in the opposite non-trained hand. Here, we test the hypothesis that progressively increasing task difficulty during long-term skill training with the dominant right hand increase performance and corticomotor...... and accuracy to individual proficiency promotes motor skill learning and drives the iM1-CSE resulting in enhanced performance of the non-trained hand. The results underline the importance of increasing task difficulty progressively and individually in skill learning and rehabilitation training. This article...... excitability of the left non-trained hand. Subjects practiced a visuomotor tracking task engaging right digit V for 6 weeks with either progressively increasing task difficulty (PT) or no progression (NPT). Corticospinal excitability(CSE) was evaluated from the resting motor threshold(rMT) and recruitment...

Long-term progressive motor skill training enhances corticospinal excitability for the ipsilateral hemisphere and motor performance of the untrained hand

DEFF Research Database (Denmark)

Christiansen, Lasse; Larsen, Malte Nejst; Grey, Michael James

2017-01-01

It is well established that unilateral motor practice can lead to increased performance in the opposite non-trained hand. Here, we test the hypothesis that progressively increasing task difficulty during long-term skill training with the dominant right hand increase performance and corticomotor...... demands for timing and accuracy to individual proficiency promotes motor skill learning and drives the iM1-CSE resulting in enhanced performance of the non-trained hand. The results underline the importance of increasing task difficulty progressively and individually in skill learning and rehabilitation...... excitability of the left non-trained hand. Subjects practiced a visuomotor tracking task engaging right digit V for 6 weeks with either progressively increasing task difficulty (PT) or no progression (NPT). Corticospinal excitability (CSE) was evaluated from the resting motor threshold (rMT) and recruitment...

ANABOLIC STEROIDS HAVE LONG-LASTING EFFECTS ON MALE SOCIAL BEHAVIORS

Science.gov (United States)

Salas-Ramirez, Kaliris Y.; Montalto, Pamela R.; Sisk, Cheryl L.

2010-01-01

Anabolic androgenic steroids (AAS) use by adolescents is steadily increasing. Adolescence involves remodeling of steroid-sensitive neural circuits that mediate social behaviors, and previous studies using animal models document effects of AAS on male social behaviors. The present experiments tested whether AAS have persistent and more pronounced behavioral consequences when drug exposure occurs during adolescence as compared to exposure in adulthood. Male Syrian hamsters were injected daily for 14 days with either vehicle or an AAS cocktail containing testosterone cypionate (2 mg/kg), nandrolone decanoate (2 mg/kg), and boldenone undecylenate (1 mg/kg), either during adolescence (27-41 days of age) or adulthood (63-77 days of age). As adults, subjects were tested two or four weeks after the last injection for either sexual behavior with a receptive female or male-male agonistic behavior in a resident-intruder test. Compared with vehicle-treated males, AAS-treated males, regardless of age of treatment, displayed fewer long intromissions and a significant increase in latency to the first long intromission, indicative of reduced potential to reach sexual satiety. Increased aggression was observed in males exposed to AAS compared with males treated with vehicle, independently of age of AAS treatment. However, unlike hamsters exposed to AAS in adulthood, hamsters exposed to AAS during adolescence did not display any submissive or risk-assessment behaviors up to 4 weeks after discontinuation of AAS treatment. Thus, AAS have long-lasting effects on male sexual and agonistic behaviors, with AAS exposure during adolescence resulting in a more pronounced reduction in submissive behavior compared to AAS exposure in adulthood. PMID:20036695

Mapping for Acute Transvenous Phrenic Nerve Stimulation Study (MAPS Study).

Science.gov (United States)

Dekker, Lukas R C; Gerritse, Bart; Scheiner, Avram; Kornet, Lilian

2017-03-01

Central sleep apnea syndrome, correlated with the occurrence of heart failure, is characterized by periods of insufficient ventilation during sleep. This acute study in 15 patients aims to map the venous system and determine if diaphragmatic movement can be achieved by phrenic nerve stimulation at various locations within the venous system. Subjects underwent a scheduled catheter ablation procedure. During the procedural waiting time, one multielectrode electrophysiology catheter was subsequently placed at the superior and inferior vena cava and the junctions of the left jugular and left brachiocephalic vein and right jugular and right brachiocephalic vein, for phrenic nerve stimulation (1-2 seconds ON/2-3 seconds OFF, 40 Hz, pulse width 210 μs). Diaphragmatic movement was assessed manually and by a breathing mask. During a follow-up assessment between 2 and 4 weeks postprocedure, occurrence of adverse events was assessed. In all patients diaphragmatic movement was induced at one or more locations using a median threshold of at least 2 V and maximally 7.5 V (i.e., e 3.3 mA, 14.2 mA). The lowest median current to obtain diaphragmatic stimulation without discomfort was found for the right brachiocephalic vein (4.7 mA). In 12/15 patients diaphragmatic movement could be induced without any discomfort, but in three patients hiccups occurred. Diaphragmatic stimulation from the brachiocephalic and caval veins is feasible. Potential side effects should be eliminated by adapting the stimulation pattern. This information could be used to design a catheter, combining cardiac pacing with enhancing diaphragm movement during a sleep apnea episode. © 2017 Wiley Periodicals, Inc.

Phrenic nerve paralysis during cryoballoon ablation for atrial fibrillation: a comparison between the first- and second-generation balloon

NARCIS (Netherlands)

Casado-Arroyo, R.; Chierchia, G.B.; Conte, G.; Levinstein, M.; Sieira, J.; Rodriguez-Manero, M.; Giovanni, G.; Baltogiannis, Y.; Wauters, K.; Asmundis, C. de; Sarkozy, A.; Brugada, P.

2013-01-01

BACKGROUND: Phrenic nerve palsy (PNP) is the most frequently observed complication during cryoballoon ablation (CB; Arctic Front, Medtronic, MN) occurring in roughly 7%-9% of the cases. The new second-generation cryoballoon ablation Arctic Front Advance (CB-A) (Arctic Front) has recently been

Characteristics of long-lasting haze episodes observed in Seoul, South Korea, for 2009-2014

Science.gov (United States)

Lee, Hae-Jung; Kim, Jeong Eun; Cha, Joo Wan; Song, Seungjoo; Ryoo, Sang-Boom; Kim, Yong Pyo

2018-03-01

The meteorological, physical, chemical, and optical characteristics of long-lasting haze in Seoul were studied. Four episodes were observed between 2009 and 2014, all in winter. PM10 mass concentration (PM10), chemical species, and aerosol optical depth (AOD) were analyzed along with the synoptic meteorological conditions. During the episodes, the temporal variations of the PM10 generally proceeded from the west along the Yellow Sea. The ground-based AOD was also high in Seoul and other sites. High AOD (MODIS) distributions were observed to move from China to Korea. The high sulfate concentration, along with the high sulfur oxidation ratio value of the third and fourth episodes (Eps. 3 and 4), respectively, corroborated the possible long-range transport of air pollutants. Stagnant meteorological conditions were a reason for the occurrence of long-lasting hazes. An anticyclone system had a dominant influence on the Korean peninsula during all episodes. The air mass over China was able to rise, and that over Korea was more stagnant in terms of climatology except Ep. 2. In addition to transport from outside, locally emitted air pollutants contributed to the PM10 partly due to the stagnant conditions, during which diurnal variations in NO2 and nitrates showed similar peak times during Eps. 3 and 4. Analysis of the episodes consistently showed that the long-lasting haze episodes were influenced by both the long-range transport of air pollutants from outside Seoul, mostly from China, and the accumulation of air pollutants that were locally emitted and transformed.

Application of stepping motor

International Nuclear Information System (INIS)

1980-10-01

This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

Long-term outcome of neurosurgical untethering on neurosegmental motor and ambulation levels

NARCIS (Netherlands)

Schoenmakers, M. A. G. C.; Gooskens, R. H. J. M.; Gulmans, V. A. M.; Hanlo, P. W.; Vandertop, W. P.; Uiterwaal, C. S. P. M.; Helders, P. J. M.

2003-01-01

The aim of this study was to determine the long-term outcome of neurosurgical untethering on neurosegmental motor level and ambulation level in children with tethered spinal cord syndrome. Forty-four children were operated on (17 males, 27 females; mean age at operation 6 years 2 months, SD 5

Complete reorganization of the motor cortex of adult rats following long-term spinal cord injuries.

Science.gov (United States)

Tandon, Shashank; Kambi, Niranjan; Mohammed, Hisham; Jain, Neeraj

2013-07-01

Understanding brain reorganization following long-term spinal cord injuries is important for optimizing recoveries based on residual function as well as developing brain-controlled assistive devices. Although it has been shown that the motor cortex undergoes partial reorganization within a few weeks after peripheral and spinal cord injuries, it is not known if the motor cortex of rats is capable of large-scale reorganization after longer recovery periods. Here we determined the organization of the rat (Rattus norvegicus) motor cortex at 5 or more months after chronic lesions of the spinal cord at cervical levels using intracortical microstimulation. The results show that, in the rats with the lesions, stimulation of neurons in the de-efferented forelimb motor cortex no longer evokes movements of the forelimb. Instead, movements of the body parts in the adjacent representations, namely the whiskers and neck were evoked. In addition, at many sites, movements of the ipsilateral forelimb were observed at threshold currents. The extent of representations of the eye, jaw and tongue movements was unaltered by the lesion. Thus, large-scale reorganization of the motor cortex leads to complete filling-in of the de-efferented cortex by neighboring representations following long-term partial spinal cord injuries at cervical levels in adult rats. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance.

Science.gov (United States)

Molero-Chamizo, Andrés; Alameda Bailén, José R; Garrido Béjar, Tamara; García López, Macarena; Jaén Rodríguez, Inmaculada; Gutiérrez Lérida, Carolina; Pérez Panal, Silvia; González Ángel, Gloria; Lemus Corchero, Laura; Ruiz Vega, María J; Nitsche, Michael A; Rivera-Urbina, Guadalupe N

2018-02-01

Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS-namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

Protective effects of long-term lithium administration in a slowly progressive SMA mouse model.

Science.gov (United States)

Biagioni, Francesca; Ferrucci, Michela; Ryskalin, Larisa; Fulceri, Federica; Lazzeri, Gloria; Calierno, Maria Teresa; Busceti, Carla L; Ruffoli, Riccardo; Fornai, Francesco

2017-12-01

In the present study we evaluated the long-term effects of lithium administration to a knock-out double transgenic mouse model (Smn-/-; SMN1A2G+/-; SMN2+/+) of Spinal Muscle Atrophy type III (SMA-III). This model is characterized by very low levels of the survival motor neuron protein, slow disease progression and motor neuron loss, which enables to detect disease-modifying effects at delayed time intervals. Lithium administration attenuates the decrease in motor activity and provides full protection from motor neuron loss occurring in SMA-III mice, throughout the disease course. In addition, lithium prevents motor neuron enlargement and motor neuron heterotopy and suppresses the occurrence of radial-like glial fibrillary acidic protein immunostaining in the ventral white matter of SMA-III mice. In SMA-III mice long-term lithium administration determines a dramatic increase of survival motor neuron protein levels in the spinal cord. These data demonstrate that long-term lithium administration during a long-lasting motor neuron disorder attenuates behavioural deficit and neuropathology. Since low level of survival motor neuron protein is bound to disease severity in SMA, the robust increase in protein level produced by lithium provides solid evidence which calls for further investigations considering lithium in the long-term treatment of spinal muscle atrophy.

Dearomatized white spirit inhalation exposure causes long-lasting neurophysiological changes in rats

DEFF Research Database (Denmark)

Lund, S. P.; Simonsen, L.; Hass, Ulla

1996-01-01

Dearomatized white spirit inhalation exposure causes long-lasting neurophysioloical changes in rats. NEUROTOXICOL TERATOL 18(1), 67-76, 1996. -Exposure for 6 h per day, 5 days per week, during a period of 6 months to the organic solvent dearomatized white spirit (0, 400, and 800 ppm) was studied ...

Motor unit activity after eccentric exercise and muscle damage in humans.

Science.gov (United States)

Semmler, J G

2014-04-01

It is well known that unaccustomed eccentric exercise leads to muscle damage and soreness, which can produce long-lasting effects on muscle function. How this muscle damage influences muscle activation is poorly understood. The purpose of this brief review is to highlight the effect of eccentric exercise on the activation of muscle by the nervous system, by examining the change in motor unit activity obtained from surface electromyography (EMG) and intramuscular recordings. Previous research shows that eccentric exercise produces unusual changes in the EMG–force relation that influences motor performance during isometric, shortening and lengthening muscle contractions and during fatiguing tasks. When examining the effect of eccentric exercise at the single motor unit level, there are substantial changes in recruitment thresholds, discharge rates, motor unit conduction velocities and synchronization, which can last for up to 1 week after eccentric exercise. Examining the time course of these changes suggests that the increased submaximal EMG after eccentric exercise most likely occurs through a decrease in motor unit conduction velocity and an increase in motor unit activity related to antagonist muscle coactivation and low-frequency fatigue. Furthermore, there is a commonly held view that eccentric exercise produces preferential damage to high-threshold motor units, but the evidence for this in humans is limited. Further research is needed to establish whether there is preferential damage to high-threshold motor units after eccentric exercise in humans, preferably by linking changes in motor unit activity with estimates of motor unit size using selective intramuscular recording techniques.

A comparison of pneumotorax and phrenic nerve pulsy complications using the methods: supraclavicular nerve block, routine and ten degree cephalic route

Directory of Open Access Journals (Sweden)

hasan Teimori

2004-08-01

Conclusions: Therefore in this method, incidence of pneumothorax and phrenic never pulsy is decreased. Suggested that this method and the other methods compare and use this method with more confidence.

A long-memory model of motor learning in the saccadic system: a regime-switching approach.

Science.gov (United States)

Wong, Aaron L; Shelhamer, Mark

2013-08-01

Maintenance of movement accuracy relies on motor learning, by which prior errors guide future behavior. One aspect of this learning process involves the accurate generation of predictions of movement outcome. These predictions can, for example, drive anticipatory movements during a predictive-saccade task. Predictive saccades are rapid eye movements made to anticipated future targets based on error information from prior movements. This predictive process exhibits long-memory (fractal) behavior, as suggested by inter-trial fluctuations. Here, we model this learning process using a regime-switching approach, which avoids the computational complexities associated with true long-memory processes. The resulting model demonstrates two fundamental characteristics. First, long-memory behavior can be mimicked by a system possessing no true long-term memory, producing model outputs consistent with human-subjects performance. In contrast, the popular two-state model, which is frequently used in motor learning, cannot replicate these findings. Second, our model suggests that apparent long-term memory arises from the trade-off between correcting for the most recent movement error and maintaining consistent long-term behavior. Thus, the model surprisingly predicts that stronger long-memory behavior correlates to faster learning during adaptation (in which systematic errors drive large behavioral changes); greater apparent long-term memory indicates more effective incorporation of error from the cumulative history across trials.

TACTILE STIMULATION EVOKES LONG-LASTING POTENTIATION OF PURKINJE CELL DISCHARGE IN VIVO

Directory of Open Access Journals (Sweden)

Ramakrishnan eKanchipuram

2016-02-01

Full Text Available In the cerebellar network, a precise relationship between plasticity and neuronal discharge has been predicted. However, the potential generation of persistent changes in PC spike discharge as a consequence of plasticity following natural stimulation patterns has not been clearly determined. Here we show that facial tactile stimuli organized in theta-patterns can induce stereotyped NMDA and GABA-A receptor-dependent changes in Purkinje cell (PCs and molecular layer interneuron (MLIs firing: invariably, all PCs showed a long-lasting increase (spike-related potentiation or SR-P and MLIs a long-lasting decrease (spike-related suppression or SR-S in baseline activity and spike response probability. These observations suggests that natural sensory stimulation engages multiple long-term plastic changes that are distributed along the mossy fiber – parallel fiber pathway and operate synergistically to potentiate spike generation in PCs. In contrast, theta-pattern electrical stimulation of PFs indistinctly induced SR-P and SR-S both in PCs and MLIs, suggesting that natural sensory stimulation preordinates plasticity upstream of the PF-PC synapse. All these effects occurred in the absence of complex spike changes, supporting the theoretical prediction that Purkinje cell activity is potentiated when the mossy fiber - parallel fiber system is activated in the absence of conjunctive climbing fiber activity.

Nongenomic Actions of 17-β Estradiol Restore Respiratory Neuroplasticity in Young Ovariectomized Female Rats

Science.gov (United States)

Dougherty, Brendan J.; Kopp, Elizabeth S.

2017-01-01

Gonadal steroids modulate CNS plasticity, including phrenic long-term facilitation (pLTF), a form of spinal respiratory neuroplasticity resulting in increased phrenic nerve motor output following exposure to acute intermittent hypoxia (aIH; three 5 min episodes, 10.5% O2). Despite the importance of respiratory system neuroplasticity, and its dependence on estrogen in males, little is known about pLTF expression or mechanisms of estrogen signaling in females. Here, we tested the hypotheses that (1) pLTF expression in young, gonadally intact female rats would be expressed during estrous cycle stages in which 17β-estradiol (E2) is naturally high (e.g., proestrus vs estrus), (2) pLTF would be absent in ovariectomized (OVX) rats and in physiological conditions in which serum progesterone, but not E2, is elevated (e.g., lactating rats, 3–10 d postpartum), and (3) acute E2 administration would be sufficient to restore pLTF in OVX rats. Recordings of phrenic nerve activity in female Sprague Dawley rats (3–4 months) revealed a direct correlation between serum E2 levels and pLTF expression in cycling female rats. pLTF was abolished with OVX, but was re-established by acute E2 replacement (3 h, intraperitoneal). To identify underlying E2 signaling mechanisms, we intrathecally applied BSA-conjugated E2 over the spinal phrenic motor nucleus and found that pLTF expression was restored within 15 min, suggesting nongenomic E2 effects at membrane estrogen receptors. These data are the first to investigate the role of ovarian E2 in young cycling females, and to identify a role for nongenomic estrogen signaling in any form of respiratory system neuroplasticity. SIGNIFICANCE STATEMENT Exposure to acute intermittent hypoxia induces phrenic long-term facilitation (pLTF), a form of spinal respiratory motor plasticity that improves breathing in models of spinal cord injury. Although pathways leading to pLTF are well studied in males and estradiol (E2) is known to be required, it has

Risk of long-lasting negative cognitive consequences after electroconvulsive therapy

DEFF Research Database (Denmark)

Svendsen, Anne Marie; Miskowiak, Kamilla; Vinberg, Maj

2013-01-01

This case study describes a patient who had a unipolar depression and experienced long-lasting cognitive problems after electroconvulsive therapy (ECT). Neuropsychological testing revealed lower scores on measures of learning, memory and sustained attention. These results stress the importance...... of informing patients who have ECT of the potential cognitive consequences of this treatment as it may influence the patients' functional capabilities. Prospective studies are needed since we do not have sufficient knowledge regarding the 3-5% of these patients who experience sustained cognitive problems....

Developmental neurotoxicity of Propylthiouracil (PTU) in rats: Relationship between transient hypothyroxinemia during development and long-lasting behavioural and functional changes

International Nuclear Information System (INIS)

Axelstad, Marta; Hansen, Pernille Reimar; Boberg, Julie; Bonnichsen, Mia; Nellemann, Christine; Lund, Soren Peter; Hougaard, Karin Sorig; Hass, Ulla

2008-01-01

Markedly lowered thyroid hormone levels during development may influence a child's behaviour, intellect, and auditory function. Recent studies, indicating that even small changes in the mother's thyroid hormone status early in pregnancy may cause adverse effects on her child, have lead to increased concern for thyroid hormone disrupting chemicals in the environment. The overall aim of the study was therefore to provide a detailed knowledge on the relationship between thyroid hormone levels during development and long-lasting effects on behaviour and hearing. Groups of 16-17 pregnant rats (HanTac:WH) were dosed with PTU (0, 0.8, 1.6 or 2.4 mg/kg/day) from gestation day (GD) 7 to postnatal day (PND) 17, and the physiological and behavioural development of rat offspring was assessed. Both dams and pups in the higher dose groups had markedly decreased thyroxine (T 4 ) levels during the dosing period, and the weight and histology of the thyroid glands were severely affected. PTU exposure caused motor activity levels to decrease on PND 14, and to increase on PND 23 and in adulthood. In the adult offspring, learning and memory was impaired in the two highest dose groups when tested in the radial arm maze, and auditory function was impaired in the highest dose group. Generally, the results showed that PTU-induced hypothyroxinemia influenced the developing rat brain, and that all effects on behaviour and loss of hearing in the adult offspring were significantly correlated to reductions in T 4 during development. This supports the hypothesis that decreased T 4 may be a relevant predictor for long-lasting developmental neurotoxicity

Neonatal oxytocin manipulations have long-lasting, sexually dimorphic effects on vasopressin receptors

OpenAIRE

Bales, KL; Plotsky, PM; Young, LJ; Lim, MM; Grotte, N; Ferrer, E; Carter, CS

2007-01-01

Developmental exposure to oxytocin (OT) or oxytocin antagonists (OTAs) has been shown to cause long-lasting and often sexually dimorphic effects on social behaviors in prairie voles (Microtus ochrogaster). Because regulation of social behavior in monogamous mammals involves central receptors for OT, arginine vasopressin (AVP), and dopamine, we examined the hypothesis that the lon...

Bacterial Urease and its Role in Long-Lasting Human Diseases

Science.gov (United States)

Konieczna, Iwona; Żarnowiec, Paulina; Kwinkowski, Marek; Kolesińska, Beata; Frączyk, Justyna; Kamiński, Zbigniew; Kaca, Wiesław

2012-01-01

Urease is a virulence factor found in various pathogenic bacteria. It is essential in colonization of a host organism and in maintenance of bacterial cells in tissues. Due to its enzymatic activity, urease has a toxic effect on human cells. The presence of ureolytic activity is an important marker of a number of bacterial infections. Urease is also an immunogenic protein and is recognized by antibodies present in human sera. The presence of such antibodies is connected with progress of several long-lasting diseases, like rheumatoid arthritis, atherosclerosis or urinary tract infections. In bacterial ureases, motives with a sequence and/or structure similar to human proteins may occur. This phenomenon, known as molecular mimicry, leads to the appearance of autoantibodies, which take part in host molecules destruction. Detection of antibodies-binding motives (epitopes) in bacterial proteins is a complex process. However, organic chemistry tools, such as synthetic peptide libraries, are helpful in both, epitope mapping as well as in serologic investigations. In this review, we present a synthetic report on a molecular organization of bacterial ureases - genetic as well as structural. We characterize methods used in detecting urease and ureolytic activity, including techniques applied in disease diagnostic processes and in chemical synthesis of urease epitopes. The review also provides a summary of knowledge about a toxic effect of bacterial ureases on human body and about occurrence of anti-urease antibodies in long-lasting diseases. PMID:23305365

Contribution of 5-HT2A receptors on diaphragmatic recovery after chronic cervical spinal cord injury.

Science.gov (United States)

Lee, Kun-Ze; Gonzalez-Rothi, Elisa J

2017-10-01

Unilateral C2 spinal cord hemisection (C2Hx) interrupts bulbospinal respiratory pathways innervating ipsilateral phrenic motoneurons, resulting in cessation of ipsilateral diaphragm motor output. Plasticity within the spinal neural circuitry controlling the diaphragm can induce partial recovery of phrenic bursting which correlates with the time-dependent return of spinal serotonin (5-HT) immunoreactivity in the vicinity of phrenic motoneurons. The 5-HT 2A receptor subtype is present on phrenic motoneurons and its expression is up-regulated after cervical spinal cord injury; however the functional role of these receptors following injury has not been clearly defined. The present study evaluated the functional role of 5-HT 2A receptors by testing the hypothesis that pharmacologic blockade would attenuate diaphragm activity in rats with chronic cervical spinal cord injury. Bilateral diaphragm electromyography (EMG) was performed in vagal-intact and spontaneously breathing rats before and after intravenous administration of the 5-HT 2A receptor antagonist Ketanserin (1mg/kg). Intravenous ketanserin significantly attenuated ipsilateral diaphragm EMG activity in C2Hx animals but had no impact on diaphragm output in uninjured animals. We conclude that 5-HT 2A receptor activation contributes to the recovery of ipsilateral phrenic motor output after chronic cervical spinal cord injury. Copyright © 2017 Elsevier B.V. All rights reserved.

Electric Motor Thermal Management

Energy Technology Data Exchange (ETDEWEB)

Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-01

Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

Test of a motor theory of long-term auditory memory.

Science.gov (United States)

Schulze, Katrin; Vargha-Khadem, Faraneh; Mishkin, Mortimer

2012-05-01

Monkeys can easily form lasting central representations of visual and tactile stimuli, yet they seem unable to do the same with sounds. Humans, by contrast, are highly proficient in auditory long-term memory (LTM). These mnemonic differences within and between species raise the question of whether the human ability is supported in some way by speech and language, e.g., through subvocal reproduction of speech sounds and by covert verbal labeling of environmental stimuli. If so, the explanation could be that storing rapidly fluctuating acoustic signals requires assistance from the motor system, which is uniquely organized to chain-link rapid sequences. To test this hypothesis, we compared the ability of normal participants to recognize lists of stimuli that can be easily reproduced, labeled, or both (pseudowords, nonverbal sounds, and words, respectively) versus their ability to recognize a list of stimuli that can be reproduced or labeled only with great difficulty (reversed words, i.e., words played backward). Recognition scores after 5-min delays filled with articulatory-suppression tasks were relatively high (75-80% correct) for all sound types except reversed words; the latter yielded scores that were not far above chance (58% correct), even though these stimuli were discriminated nearly perfectly when presented as reversed-word pairs at short intrapair intervals. The combined results provide preliminary support for the hypothesis that participation of the oromotor system may be essential for laying down the memory of speech sounds and, indeed, that speech and auditory memory may be so critically dependent on each other that they had to coevolve.

Long-latency TMS-evoked potentials during motor execution and inhibition

Directory of Open Access Journals (Sweden)

Kentaro eYamanaka

2013-11-01

Full Text Available Transcranial magnetic stimulation (TMS has often been used in conjunction with electroencephalography (EEG, which is effective for the direct demonstration of cortical reactivity and corticocortical connectivity during cognitive tasks through the spatio-temporal pattern of long-latency TMS-evoked potentials (TEPs. However, it remains unclear what pattern is associated with the inhibition of a planned motor response. Therefore, we performed TMS-EEG recording during a go/stop task, in which participants were instructed to click a computer mouse with a right index finger when an indicator that was moving with a constant velocity reached a target (go trial or to avoid the click when the indicator randomly stopped just before it reached the target (stop trial. Single-pulse TMS to the left (contralateral or right (ipsilateral motor cortex was applied 500 ms before or just at the target time. TEPs related to motor execution and inhibition were obtained by subtractions between averaged EEG waveforms with and without TMS. As a result, in TEPs induced by both contralateral and ipsilateral TMS, small oscillations were followed by a prominent negative deflection around the TMS site peaking at approximately 100 ms post-TMS (N100, and a less pronounced later positive component (LPC over the broad areas that was centered at the midline-central site in both go and stop trials. However, compared to the pattern in go and stop trials with TMS at 500 ms before the target time, N100 and LPC were differently modulated in the go and stop trials with TMS just at the target time. The amplitudes of both N100 and LPC decreased in go trials, while the amplitude of LPC decreased and the latency of LPC was delayed in both go and stop trials. These results suggested that TMS-induced neuronal reactions in the motor cortex and subsequent their propagation to surrounding cortical areas might change functionally according to task demand when executing and inhibiting a motor

Reversal of long-term potentiation-like plasticity processes after motor learning disrupts skill retention.

Science.gov (United States)

Cantarero, Gabriela; Lloyd, Ashley; Celnik, Pablo

2013-07-31

Plasticity of synaptic connections in the primary motor cortex (M1) is thought to play an essential role in learning and memory. Human and animal studies have shown that motor learning results in long-term potentiation (LTP)-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. Moreover, biochemical processes essential for LTP are also crucial for certain types of motor learning and memory. Thus, it has been speculated that the occlusion of LTP-like plasticity after learning, indicative of how much LTP was used to learn, is essential for retention. Here we provide supporting evidence of it in humans. Induction of LTP-like plasticity can be abolished using a depotentiation protocol (DePo) consisting of brief continuous theta burst stimulation. We used transcranial magnetic stimulation to assess whether application of DePo over M1 after motor learning affected (1) occlusion of LTP-like plasticity and (2) retention of motor skill learning. We found that the magnitude of motor memory retention is proportional to the magnitude of occlusion of LTP-like plasticity. Moreover, DePo stimulation over M1, but not over a control site, reversed the occlusion of LTP-like plasticity induced by motor learning and disrupted skill retention relative to control subjects. Altogether, these results provide evidence of a link between occlusion of LTP-like plasticity and retention and that this measure could be used as a biomarker to predict retention. Importantly, attempts to reverse the occlusion of LTP-like plasticity after motor learning comes with the cost of reducing retention of motor learning.

Combined motor disturbances following severe traumatic brain injury: an integrative long-term treatment approach.

Science.gov (United States)

Keren, O; Reznik, J; Groswasser, Z

2001-07-01

Patients surviving severe traumatic brain injury (TBI) often suffer from residual impairments in motor control, communication skills, cognition and social behaviour. These distinctly hamper their capability to return to their 'pre-trauma' activity. Comprehensive and integrated rehabilitation programmes initiate, during the acute phase, a prolonged treatment process which starts at the most sophisticated medical systems. There is no clear end point for the treatment of these patients, since the recovery process and the rehabilitation activity may continue for years, even after patients return home to live with their families. The inherent inability to make a firm early prediction regarding outcome of patients and the late appearance of additional symptoms stress the need for a comprehensive close long-term follow-up. The following presentation concerns the description of the treatment strategy and long-term improvement of a 22-year-old male who suffered from very severe TBI. On admission to the emergency room, he was in the decerebrated position and his Glasgow Coma Scale (GCS) was at the lowest (3). The focus of this presentation is on the recovery of motor function. The initial motor disabilities included weakness in all four limbs, in particular left hemiplegia, and right hemiparesis with severe bilateral ataxic elements and a marked tremor of the right arm. Range of motion was limited in hips, and he suffered from stiff trunk and neck. Goals of physiotherapy were directed towards improving range of motion (ROM) and active movement. Casting, use of orthoses, biofeedback, hydrotherapy, hippotherapy, medication and nerve blocks for reducing spasticity were timely applied during the process. The motor improvement in this very severe TBI patient who is now over 3 years post-injury still continues and has a functional meaning. He has succeeded in being able to stand up by himself from a chair and is able to walk unaided and without orthoses for very short distances

Heavy Chronic Ethanol Exposure From Adolescence to Adulthood Induces Cerebellar Neuronal Loss and Motor Function Damage in Female Rats

Directory of Open Access Journals (Sweden)

Fernando B. R. da Silva

2018-05-01

Full Text Available Over the last years, heavy ethanol consumption by teenagers/younger adults has increased considerably among females. However, few studies have addressed the long-term impact on brain structures’ morphology and function of chronic exposure to high ethanol doses from adolescence to adulthood in females. In line with this idea, in the current study we investigated whether heavy chronic ethanol exposure during adolescence to adulthood may induce motor impairments and morphological and cellular alterations in the cerebellum of female rats. Adolescent female Wistar rats (35 days old were treated with distilled water or ethanol (6.5 g/kg/day, 22.5% w/v during 55 days by gavage. At 90 days of age, motor function of animals was assessed using open field (OF, pole, beam walking and rotarod tests. Following completion of behavioral tests, morphological and immunohistochemical analyses of the cerebellum were performed. Chronic ethanol exposure impaired significantly motor performance of female rats, inducing spontaneous locomotor activity deficits, bradykinesia, incoordination and motor learning disruption. Moreover, histological analysis revealed that ethanol exposure induced atrophy and neuronal loss in the cerebellum. These findings indicate that heavy ethanol exposure during adolescence is associated with long-lasting cerebellar degeneration and motor impairments in female rats.

A Beautician’s Dystonia: Long-Lasting Effect of Botulinum Toxin

Directory of Open Access Journals (Sweden)

Siria Di Martino

2014-01-01

Full Text Available Treatment options for dystonia are not curative but symptomatic; the treatment of choice for focal dystonias is repeated botulinum toxin injections. Here, we present the case of a 46-year-old beautician with focal dystonia in her left hand that affected her ability to work. Pharmacological treatment with clonazepam and gabapentin failed to resolve her symptoms and was discontinued due to side effects (sleepiness, gastrointestinal disorders. Intramuscular injection of botulinum toxin (incobotulinumtoxinA, Xeomin into the extensor digitorum communis (35 U, flexor carpi radialis (35 U, and flexor digitorum superficialis (30 U muscles resulted in complete resolution of symptoms at clinical assessments at 1, 3, 6, and 10 months after the injections, confirmed by the results of surface electromyography 10 months after treatment. The patient was able to work again 1 month after treatment. No reinjection has been necessary at the last evaluation (12 months after treatment. In conclusion, botulinum toxin is an effective treatment for focal dystonia that can have long-lasting effects and can improve patients’ ability to work and quality of life.

Outcome following phrenic nerve transfer to musculocutaneous nerve in patients with traumatic brachial palsy: a qualitative systematic review.

Science.gov (United States)

de Mendonça Cardoso, Marcio; Gepp, Ricardo; Correa, José Fernando Guedes

2016-09-01

The phrenic nerve can be transferred to the musculocutaneous nerve in patients with traumatic brachial plexus palsy in order to recover biceps strength, but the results are controversial. There is also a concern about pulmonary function after phrenic nerve transection. In this paper, we performed a qualitative systematic review, evaluating outcomes after this procedure. A systematic review of published studies was undertaken in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Data were extracted from the selected papers and related to: publication, study design, outcome (biceps strength in accordance with BMRC and pulmonary function) and population. Study quality was assessed using the "strengthening the reporting of observational studies in epidemiology" (STROBE) standard or the CONSORT checklist, depending on the study design. Seven studies were selected for this systematic review after applying inclusion and exclusion criteria. One hundred twenty-four patients completed follow-up, and most of them were graded M3 or M4 (70.1 %) for biceps strength at the final evaluation. Pulmonary function was analyzed in five studies. It was not possible to perform a statistical comparison between studies because the authors used different parameters for evaluation. Most of the patients exhibited a decrease in pulmonary function tests immediately after surgery, with recovery in the following months. Study quality was determined using STROBE in six articles, and the global score varied from 8 to 21. Phrenic nerve transfer to the musculocutaneous nerve can recover biceps strength ≥M3 (BMRC) in most patients with traumatic brachial plexus injury. Early postoperative findings revealed that the development of pulmonary symptoms is rare, but it cannot be concluded that the procedure is safe because there is no study evaluating pulmonary function in old age.

Long-lasting ovulation inhibition with a new injectable progestagen ORG-2154.

Science.gov (United States)

Coutinho, E M; De Souza, J C; Barbosa, I C; Dourado Silva, V

1982-06-01

A new long-acting injectable progestagen was tested in 15 women who volunteered for the study. The occurrence of ovulation was assumed by the elevation of progesterone levels above 2ng/ml following a pre-ovulatory estradiol peak. Following a 200mg injection, ovulation was inhibited in all 15 women for five to ten months. In four subjects the interval between the injection and the first progesterone peak was five months. For eight, the interval was six to eight months. In the other three women, ovulation occurred more than eight months following injection. Bleeding episodes, similar to menstruation, occurred in most patients. Bleeding intervals lasting longer than 45 days occurred in nine subjects but more prolonged amenorrhea lasting longer than 60 days was reported by only five subjects. Blood chemistry which included blood cell counts, cholesterol, glucose, alkaline phosphatase, transaminases, urea nitrogen and creatinine remained within normal limits throughout the treatment.

An Element of Determinism in a Stochastic Flagellar Motor Switch.

Science.gov (United States)

Xie, Li; Altindal, Tuba; Wu, Xiao-Lun

2015-01-01

Marine bacterium Vibrio alginolyticus uses a single polar flagellum to navigate in an aqueous environment. Similar to Escherichia coli cells, the polar flagellar motor has two states; when the motor is counter-clockwise, the cell swims forward and when the motor is clockwise, the cell swims backward. V. alginolyticus also incorporates a direction randomization step at the start of the forward swimming interval by flicking its flagellum. To gain an understanding on how the polar flagellar motor switch is regulated, distributions of the forward Δf and backward Δb intervals are investigated herein. We found that the steady-state probability density functions, P(Δf) and P(Δb), of freely swimming bacteria are strongly peaked at a finite time, suggesting that the motor switch is not Poissonian. The short-time inhibition is sufficiently strong and long lasting, i.e., several hundred milliseconds for both intervals, which is readily observed and characterized. Treating motor reversal dynamics as a first-passage problem, which results from conformation fluctuations of the motor switch, we calculated P(Δf) and P(Δb) and found good agreement with the measurements.

Activity enhances dopaminergic long-duration response in Parkinson disease

Science.gov (United States)

Auinger, Peggy; Fahn, Stanley; Oakes, David; Shoulson, Ira; Kieburtz, Karl; Rudolph, Alice; Marek, Kenneth; Seibyl, John; Lang, Anthony; Olanow, C. Warren; Tanner, Caroline; Schifitto, Giovanni; Zhao, Hongwei; Reyes, Lydia; Shinaman, Aileen; Comella, Cynthia L.; Goetz, Christopher; Blasucci, Lucia M.; Samanta, Johan; Stacy, Mark; Williamson, Kelli; Harrigan, Mary; Greene, Paul; Ford, Blair; Moskowitz, Carol; Truong, Daniel D.; Pathak, Mayank; Jankovic, Joseph; Ondo, William; Atassi, Farah; Hunter, Christine; Jacques, Carol; Friedman, Joseph H.; Lannon, Margaret; Russell, David S.; Jennings, Danna; Fussell, Barbara; Standaert, David; Schwarzschild, Michael A.; Growdon, John H.; Tennis, Marsha; Gauthier, Serge; Panisset, Michel; Hall, Jean; Gancher, Stephen; Hammerstad, John P.; Stone, Claudia; Alexander-Brown, Barbara; Factor, Stewart A.; Molho, Eric; Brown, Diane; Evans, Sharon; Clark, Jeffrey; Manyam, Bala; Simpson, Patricia; Wulbrecht, Brian; Whetteckey, Jacqueline; Martin, Wayne; Roberts, Ted; King, Pamela; Hauser, Robert; Zesiewicz, Theresa; Gauger, Lisa; Trugman, Joel; Wooten, G. Frederick; Rost-Ruffner, Elke; Perlmutter, Joel; Racette, Brad A.; Suchowersky, Oksana; Ranawaya, Ranjit; Wood, Susan; Pantella, Carol; Kurlan, Roger; Richard, Irene; Pearson, Nancy; Caviness, John N.; Adler, Charles; Lind, Marlene; Simuni, Tanya; Siderowf, Andrew; Colcher, Amy; Lloyd, Mary; Weiner, William; Shulman, Lisa; Koller, William; Lyons, Kelly; Feldman, Robert G.; Saint-Hilaire, Marie H.; Ellias, Samuel; Thomas, Cathi-Ann; Juncos, Jorge; Watts, Ray; Partlow, Anna; Tetrud, James; Togasaki, Daniel M.; Stewart, Tracy; Mark, Margery H.; Sage, Jacob I.; Caputo, Debbie; Gould, Harry; Rao, Jayaraman; McKendrick, Ann; Brin, Mitchell; Danisi, Fabio; Benabou, Reina; Hubble, Jean; Paulson, George W.; Reider, Carson; Birnbaum, Alex; Miyasaki, Janis; Johnston, Lisa; So, Julie; Pahwa, Rajesh; Dubinsky, Richard M.; Wszolek, Zbigniew; Uitti, Ryan; Turk, Margaret; Tuite, Paul; Rottenberg, David; Hansen, Joy; Ramos, Serrano; Waters, Cheryl; Lew, Mark; Welsh, Mickie; Kawai, Connie; O'Brien, Christopher; Kumar, Rajeev; Seeberger, Lauren; Judd, Deborah; Barclay, C. Lynn; Grimes, David A.; Sutherland, Laura; Dawson, Ted; Reich, Stephen; Dunlop, Rebecca; Albin, Roger; Frey, Kirk; Wernette, Kristine; Fahn, Stanley; Oakes, David; Shoulson, Ira; Kieburtz, Karl; Rudolph, Alice; Marek, Kenneth; Seibyl, John; Lang, Anthony; Olanow, C. Warren; Tanner, Caroline; Schifitto, Giovanni; Zhao, Hongwei; Reyes, Lydia; Shinaman, Aileen; Comella, Cynthia L.; Goetz, Christopher; Blasucci, Lucia M.; Samanta, Johan; Stacy, Mark; Williamson, Kelli; Harrigan, Mary; Greene, Paul; Ford, Blair; Moskowitz, Carol; Truong, Daniel D.; Pathak, Mayank; Jankovic, Joseph; Ondo, William; Atassi, Farah; Hunter, Christine; Jacques, Carol; Friedman, Joseph H.; Lannon, Margaret; Russell, David S.; Jennings, Danna; Fussell, Barbara; Standaert, David; Schwarzschild, Michael A.; Growdon, John H.; Tennis, Marsha; Gauthier, Serge; Panisset, Michel; Hall, Jean; Gancher, Stephen; Hammerstad, John P.; Stone, Claudia; Alexander-Brown, Barbara; Factor, Stewart A.; Molho, Eric; Brown, Diane; Evans, Sharon; Clark, Jeffrey; Manyam, Bala; Simpson, Patricia; Wulbrecht, Brian; Whetteckey, Jacqueline; Martin, Wayne; Roberts, Ted; King, Pamela; Hauser, Robert; Zesiewicz, Theresa; Gauger, Lisa; Trugman, Joel; Wooten, G. Frederick; Rost-Ruffner, Elke; Perlmutter, Joel; Racette, Brad A.; Suchowersky, Oksana; Ranawaya, Ranjit; Wood, Susan; Pantella, Carol; Kurlan, Roger; Richard, Irene; Pearson, Nancy; Caviness, John N.; Adler, Charles; Lind, Marlene; Simuni, Tanya; Siderowf, Andrew; Colcher, Amy; Lloyd, Mary; Weiner, William; Shulman, Lisa; Koller, William; Lyons, Kelly; Feldman, Robert G.; Saint-Hilaire, Marie H.; Ellias, Samuel; Thomas, Cathi-Ann; Juncos, Jorge; Watts, Ray; Partlow, Anna; Tetrud, James; Togasaki, Daniel M.; Stewart, Tracy; Mark, Margery H.; Sage, Jacob I.; Caputo, Debbie; Gould, Harry; Rao, Jayaraman; McKendrick, Ann; Brin, Mitchell; Danisi, Fabio; Benabou, Reina; Hubble, Jean; Paulson, George W.; Reider, Carson; Birnbaum, Alex; Miyasaki, Janis; Johnston, Lisa; So, Julie; Pahwa, Rajesh; Dubinsky, Richard M.; Wszolek, Zbigniew; Uitti, Ryan; Turk, Margaret; Tuite, Paul; Rottenberg, David; Hansen, Joy; Ramos, Serrano; Waters, Cheryl; Lew, Mark; Welsh, Mickie; Kawai, Connie; O'Brien, Christopher; Kumar, Rajeev; Seeberger, Lauren; Judd, Deborah; Barclay, C. Lynn; Grimes, David A.; Sutherland, Laura; Dawson, Ted; Reich, Stephen; Dunlop, Rebecca; Albin, Roger; Frey, Kirk; Wernette, Kristine; Mendis, Tilak

2012-01-01

Objective: We tested the hypothesis that dopamine-dependent motor learning mechanism underlies the long-duration response to levodopa in Parkinson disease (PD) based on our studies in a mouse model. By data-mining the motor task performance in dominant and nondominant hands of the subjects in a double-blind randomized trial of levodopa therapy, the effects of activity and dopamine therapy were examined. Methods: We data-mined the Earlier versus Later Levodopa Therapy in Parkinson's Disease (ELLDOPA) study published in 2005 and performed statistical analysis comparing the effects of levodopa and dominance of handedness over 42 weeks. Results: The mean change in finger-tapping counts from baseline before the initiation of therapy to predose at 9 weeks and 40 weeks increased more in the dominant compared to nondominant hand in levodopa-treated subjects in a dose-dependent fashion. There was no significant difference in dominant vs nondominant hands in the placebo group. The short-duration response assessed by the difference of postdose performance compared to predose performance at the same visit did not show any significant difference between dominant vs nondominant hands. Conclusions: Active use of the dominant hand and dopamine replacement therapy produces synergistic effect on long-lasting motor task performance during “off” medication state. Such effect was confined to dopamine-responsive symptoms and not seen in dopamine-resistant symptoms such as gait and balance. We propose that long-lasting motor learning facilitated by activity and dopamine is a form of disease modification that is often seen in trials of medications that have symptomatic effects. PMID:22459675

Functional MRI neurofeedback training on connectivity between two regions induces long-lasting changes in intrinsic functional network

Directory of Open Access Journals (Sweden)

Fukuda eMegumi

2015-03-01

Full Text Available Motor or perceptual learning is known to influence functional connectivity between brain regions and induce short-term changes in the intrinsic functional networks revealed as correlations in slow blood-oxygen-level dependent (BOLD signal fluctuations. However, no cause-and-effect relationship has been elucidated between a specific change in connectivity and a long-term change in global networks. Here, we examine the hypothesis that functional connectivity (i.e. temporal correlation between two regions is increased and preserved for a long time when two regions are simultaneously activated or deactivated. Using the connectivity-neurofeedback training paradigm, subjects successfully learned to increase the correlation of activity between the lateral parietal and primary motor areas, regions that belong to different intrinsic networks and negatively correlated before training under the resting conditions. Furthermore, whole-brain hypothesis-free analysis as well as functional network analyses demonstrated that the correlation in the resting state between these areas as well as the correlation between the intrinsic networks that include the areas increased for at least two months. These findings indicate that the connectivity-neurofeedback training can cause long-term changes in intrinsic connectivity and that intrinsic networks can be shaped by experience-driven modulation of regional correlation.

Functional restoration of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization utilizing the functional spinal accessory nerve.

Science.gov (United States)

Yang, Ming-liang; Li, Jian-jun; Zhang, Shao-cheng; Du, Liang-jie; Gao, Feng; Li, Jun; Wang, Yu-ming; Gong, Hui-ming; Cheng, Liang

2011-08-01

The authors report a case of functional improvement of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization using a functional spinal accessory nerve. Complete spinal cord injury at the C-2 level was diagnosed in a 44-year-old man. Left diaphragm activity was decreased, and the right diaphragm was completely paralyzed. When the level of metabolism or activity (for example, fever, sitting, or speech) slightly increased, dyspnea occurred. The patient underwent neurotization of the right phrenic nerve with the trapezius branch of the right spinal accessory nerve at 11 months postinjury. Four weeks after surgery, training of the synchronous activities of the trapezius muscle and inspiration was conducted. Six months after surgery, motion was observed in the previously paralyzed right diaphragm. The lung function evaluation indicated improvements in vital capacity and tidal volume. This patient was able to sit in a wheelchair and conduct outdoor activities without assisted ventilation 12 months after surgery.

Development of Propulsion Inverter Control System for High-Speed Maglev based on Long Stator Linear Synchronous Motor

Directory of Open Access Journals (Sweden)

Jeong-Min Jo

2017-02-01

Full Text Available In the case of a long-stator linear drive, unlike rotative drives for which speed or position sensors are a single unit attached to the shaft, these sensors extend along the guideway. The position signals transmitted from a maglev vehicle cannot meet the need of the real-time propulsion control in the on-ground inverter power substations. In this paper the design of the propulsion inverter control system with a position estimator for driving a long-stator synchronous motor in a high-speed maglev train is proposed. The experiments have been carried out at the 150 m long guideway at the O-song test track. To investigate the performance of the position estimator, the propulsion control system with, and without, the position estimator are compared. The result confirms that the proposed strategy can meet the dynamic property needs of the propulsion inverter control system for driving long-stator linear synchronous motors.

The usefulness of computerized tomography in the evaluation of cardio phrenic angle lesion

International Nuclear Information System (INIS)

Marins, J.L.; Cazerta, N.M.G.; Prando, A.; Pereira, R.M.

1988-01-01

The usefulness of computed tomography (CT) in categorizing lesions of the cardio phrenic angles is showed. Twenty five patients with abnormalities in these sites were studied by CT. These abnormalities included ten cases of lymphomatous adenopathy, two cases of metastatic adenopathy, four cases of pericardial cyst, four cases of loculated pleural effusion, and five cases of prominent epicardial fat. A correct evaluation of all cases was possible by utilizing the CT densities numbers and the topographic characteristics of the lesions. CT showed high sensitivity in detecting paracardiac adenopathy which may affect the staging and treatment of neoplasia. (author)

Diaphragm electromyographic activity following unilateral midcervical contusion injury in rats

Science.gov (United States)

Sieck, Gary C.

2016-01-01

Contusion-type injuries to the spinal cord are characterized by tissue loss and disruption of spinal pathways. Midcervical spinal cord injuries impair the function of respiratory muscles and may contribute to significant respiratory complications. This study systematically assessed the impact of a 100-kDy unilateral C4 contusion injury on diaphragm muscle activity across a range of motor behaviors in rats. Chronic diaphragm electromyography (EMG) was recorded before injury and at 1 and 7 days postinjury (DPI). Histological analyses assessed the extent of perineuronal net formation, white-matter sparing, and phrenic motoneuron loss. At 7 DPI, ∼45% of phrenic motoneurons were lost ipsilaterally. Relative diaphragm root mean square (RMS) EMG activity increased bilaterally across a range of motor behaviors by 7 DPI. The increase in diaphragm RMS EMG activity was associated with an increase in neural drive (RMS value at 75 ms after the onset of diaphragm activity) and was more pronounced during higher force, nonventilatory motor behaviors. Animals in the contusion group displayed a transient decrease in respiratory rate and an increase in burst duration at 1 DPI. By 7 days, following midcervical contusion, there was significant perineuronal net formation and white-matter loss that spanned 1 mm around the injury epicenter. Taken together, these findings are consistent with increased recruitment of remaining motor units, including more fatigable, high-threshold motor units, during higher force, nonventilatory behaviors. Changes in diaphragm EMG activity following midcervical contusion injury reflect complex adaptations in neuromotor control that may increase the risk of motor-unit fatigue and compromise the ability to sustain higher force diaphragm efforts. NEW & NOTEWORTHY The present study shows that unilateral contusion injury at C4 results in substantial loss of phrenic motoneurons but increased diaphragm muscle activity across a range of ventilatory and higher

After-effects of anodal transcranial direct current stimulation on the excitability of the motor cortex in rats.

Science.gov (United States)

Koo, Ho; Kim, Min Sun; Han, Sang Who; Paulus, Walter; Nitche, Michael A; Kim, Yun-Hee; Kim, Hyoung-Ihl; Ko, Sung-Hwa; Shin, Yong-Il

2016-09-21

Transcranial direct current stimulation (tDCS) is increasingly seen as a useful tool for noninvasive cortical neuromodulation. A number of studies in humans have shown that when tDCS is applied to the motor cortex it can modulate cortical excitability. It is especially interesting to note that when applied with sufficient duration and intensity, tDCS can enable long-lasting neuroplastic effects. However, the mechanism by which tDCS exerts its effects on the cortex is not fully understood. We investigated the effects of anodal tDCS under urethane anesthesia on field potentials in in vivo rats. These were measured on the skull over the right motor cortex of rats immediately after stimulating the left corpus callosum. Evoked field potentials in the motor cortex were gradually increased for more than one hour after anodal tDCS. To induce these long-lasting effects, a sufficient duration of stimulation (20 minutes or more) was found to may be required rather than high stimulation intensity. We propose that anodal tDCS with a sufficient duration of stimulation may modulate transcallosal plasticity.

Involvement of TrkB- and p75NTR-signaling pathways in two contrasting forms of long-lasting synaptic plasticity

Science.gov (United States)

Sakuragi, Shigeo; Tominaga-Yoshino, Keiko; Ogura, Akihiko

2013-11-01

The repetition of experience is often necessary to establish long-lasting memory. However, the cellular mechanisms underlying this repetition-dependent consolidation of memory remain unclear. We previously observed in organotypic slice cultures of the rodent hippocampus that repeated inductions of long-term potentiation (LTP) led to a slowly developing long-lasting synaptic enhancement coupled with synaptogenesis. We also reported that repeated inductions of long-term depression (LTD) produced a long-lasting synaptic suppression coupled with synapse elimination. We proposed these phenomena as useful in vitro models for analyzing repetition-dependent consolidation. Here, we hypothesized that the enhancement and suppression are mediated by the brain-derived neurotrophic factor (BDNF)-TrkB signaling pathway and the proBDNF-p75NTR pathway, respectively. When we masked the respective pathways, reversals of the enhancement and suppression resulted. These results suggest the alternative activation of the p75NTR pathway by BDNF under TrkB-masking conditions and of the TrkB pathway by proBDNF under p75NTR-masking conditions, thus supporting the aforementioned hypothesis.

Genetic specification of left–right asymmetry in the diaphragm muscles and their motor innervation

Science.gov (United States)

Charoy, Camille; Dinvaut, Sarah; Chaix, Yohan; Morlé, Laurette; Sanyas, Isabelle; Bozon, Muriel; Kindbeiter, Karine; Durand, Bénédicte; Skidmore, Jennifer M; De Groef, Lies; Seki, Motoaki; Moons, Lieve; Ruhrberg, Christiana; Martin, James F; Martin, Donna M; Falk, Julien; Castellani, Valerie

2017-01-01

The diaphragm muscle is essential for breathing in mammals. Its asymmetric elevation during contraction correlates with morphological features suggestive of inherent left–right (L/R) asymmetry. Whether this asymmetry is due to L versus R differences in the muscle or in the phrenic nerve activity is unknown. Here, we have combined the analysis of genetically modified mouse models with transcriptomic analysis to show that both the diaphragm muscle and phrenic nerves have asymmetries, which can be established independently of each other during early embryogenesis in pathway instructed by Nodal, a morphogen that also conveys asymmetry in other organs. We further found that phrenic motoneurons receive an early L/R genetic imprint, with L versus R differences both in Slit/Robo signaling and MMP2 activity and in the contribution of both pathways to establish phrenic nerve asymmetry. Our study therefore demonstrates L–R imprinting of spinal motoneurons and describes how L/R modulation of axon guidance signaling helps to match neural circuit formation to organ asymmetry. DOI: http://dx.doi.org/10.7554/eLife.18481.001 PMID:28639940

Tennessee and Florida: Continuity and Change in Long-Lasting State Performance Funding Systems for Higher Education. CCRC Brief. Number 43

Science.gov (United States)

Dougherty, Kevin J.; Natow, Rebecca S.

2010-01-01

This study analyzes changes over time in long-lasting state performance funding systems for higher education. It addresses two research questions: First, in what ways have long-lasting systems changed over time in funding levels, indicators used to allocate funds, and measures used for those indicators? Second, what political actors, actions, and…

Norepinephrine induces pathway-specific long-lasting potentiation and depression in the hippocampal dentate gyrus.

Science.gov (United States)

Dahl, D; Sarvey, J M

1989-01-01

The study presented here indicates that norepinephrine (NE) selectively induces long-lasting modifications of synaptically mediated responses in the dentate gyrus of the rat hippocampal slice. A low concentration of NE (1.0 microM; in the presence of 50 microM phentolamine, an alpha-adrenergic antagonist) or a 1.0 microM concentration of the specific beta-adrenergic agonist isoproterenol induced long-lasting pathway-specific alterations of granule cell electrophysiological responses. Excitatory postsynaptic potentials and population spikes evoked by stimulation of the medial perforant pathway (PP) were potentiated for more than 45 min. In contrast, responses to lateral PP stimulation were depressed for the same period. Both potentiation and depression were blocked by the beta-adrenergic antagonist propranolol (1.0 microM). These results indicate that NE can act differentially on projections to the dentate gyrus arising in the entorhinal cortex. Such selective persistent modifications of cortical circuits may be involved in processes in the mammalian brain underlying attention, learning, and memory. PMID:2734319

Long-lasting injection of solar energetic electrons into the heliosphere

Science.gov (United States)

Dresing, N.; Gómez-Herrero, R.; Heber, B.; Klassen, A.; Temmer, M.; Veronig, A.

2018-05-01

Context. The main sources of solar energetic particle (SEP) events are solar flares and shocks driven by coronal mass ejections (CMEs). While it is generally accepted that energetic protons can be accelerated by shocks, whether or not these shocks can also efficiently accelerate solar energetic electrons is still debated. In this study we present observations of the extremely widespread SEP event of 26 Dec 2013 To the knowledge of the authors, this is the widest longitudinal SEP distribution ever observed together with unusually long-lasting energetic electron anisotropies at all observer positions. Further striking features of the event are long-lasting SEP intensity increases, two distinct SEP components with the second component mainly consisting of high-energy particles, a complex associated coronal activity including a pronounced signature of a shock in radio type-II observations, and the interaction of two CMEs early in the event. Aims: The observations require a prolonged injection scenario not only for protons but also for electrons. We therefore analyze the data comprehensively to characterize the possible role of the shock for the electron event. Methods: Remote-sensing observations of the complex solar activity are combined with in situ measurements of the particle event. We also apply a graduated cylindrical shell (GCS) model to the coronagraph observations of the two associated CMEs to analyze their interaction. Results: We find that the shock alone is likely not responsible for this extremely wide SEP event. Therefore we propose a scenario of trapped energetic particles inside the CME-CME interaction region which undergo further acceleration due to the shock propagating through this region, stochastic acceleration, or ongoing reconnection processes inside the interaction region. The origin of the second component of the SEP event is likely caused by a sudden opening of the particle trap.

Long lasting behavior of Gd2O2S:Eu3+ phosphor synthesized by hydrothermal routine

International Nuclear Information System (INIS)

Hang Tao; Liu Qun; Mao Dali; Chang Chengkang

2008-01-01

This paper reports the detailed preparation process and afterglow properties of Eu 3+ activated long lasting Gd 2 O 2 S phosphor by hydrothermal routine. Rod-like Gd(OH) 3 were firstly synthesized by hydrothermal method to serve as the precursor. Long lasting Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor was obtained by calcinating the precursor with co-activators and S powder. It was found from the results that the hydrothermally prepared Gd(OH) 3 revealed a rod-like morphology, while the calcinated Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor showed a round granular shape. The morphological change can be explained by the etching effect of the melt that was formed by the carbonate and S powder during the high temperature calcination. The obtained Gd 2 O 2 S:Eu 3+ ,Ti 4+ ,Mg 2+ phosphor produced a red emission upon 243 nm UV excitation, which is a typical emission of Eu 3+ from 5 D j to 7 F j states. Long lasting behavior was observed after the UV source was switched off, due to the formation of electron traps with suitable trap depth within the matrix by the codoped Ti 4+ and Mg 2+ ions

On the control performance of motors driven by long cables for remote handling at ITER

International Nuclear Information System (INIS)

Sol, Enrique del; Meek, Richard; Ruiz Morales, Emilio; Vitelli, Ricardo; Esqué, Salvador

2016-01-01

Highlights: • We show the dangerous effects of reflections on the actuator’s system. • We prove how to solve the reflections issue with a commercial LC filter. • We study the filter influence for short cables on two control modes. • We show the filter performance under a real remote handling operation. • We study the excellent performance of the filter for different cable lengths. - Abstract: Pulse Width Modulation (PWM) is nowadays the most used method for controlling a servo-motor. When combining PWM with motors and long cables, such as the ones that will be found at ITER, the standing waves originated are potentially very harmful for both actuator’s life span and control performance. Several methods have been investigated to cope with this issue, such as the use of chokes, filters, snubbers or active modification of the PWM signal. Of all possible locations where an electrical servo-motor could be used at ITER, the most critical scenario arises when mounting a low power motor, with a low gear ratio, in a dexterous manipulator for bilateral teleoperation. In those circumstances cable lengths of more than 150 m are expected between manipulator and control cubicle. In this paper, the effects of long cables in the system safety are analysed on a custom made test bench. The most common solutions to cope with this issue are analysed and a commercial LC filter is selected for further experimentation. An extensive set of experiments are carried out in order to validate the proposed solution for being used on remote handling equipment at ITER.

On the control performance of motors driven by long cables for remote handling at ITER

Energy Technology Data Exchange (ETDEWEB)

Sol, Enrique del, E-mail: enrique.delsol@oxfordtechnologies.co.uk [Oxford Technologies Ltd., 7 Nuffield Way, Abingdon OX141RL (United Kingdom); Meek, Richard [Oxford Technologies Ltd., 7 Nuffield Way, Abingdon OX141RL (United Kingdom); Ruiz Morales, Emilio; Vitelli, Ricardo; Esqué, Salvador [Fusion for Energy, Josep Pla, 2, Barcelona 08019 (Spain)

2016-06-15

Highlights: • We show the dangerous effects of reflections on the actuator’s system. • We prove how to solve the reflections issue with a commercial LC filter. • We study the filter influence for short cables on two control modes. • We show the filter performance under a real remote handling operation. • We study the excellent performance of the filter for different cable lengths. - Abstract: Pulse Width Modulation (PWM) is nowadays the most used method for controlling a servo-motor. When combining PWM with motors and long cables, such as the ones that will be found at ITER, the standing waves originated are potentially very harmful for both actuator’s life span and control performance. Several methods have been investigated to cope with this issue, such as the use of chokes, filters, snubbers or active modification of the PWM signal. Of all possible locations where an electrical servo-motor could be used at ITER, the most critical scenario arises when mounting a low power motor, with a low gear ratio, in a dexterous manipulator for bilateral teleoperation. In those circumstances cable lengths of more than 150 m are expected between manipulator and control cubicle. In this paper, the effects of long cables in the system safety are analysed on a custom made test bench. The most common solutions to cope with this issue are analysed and a commercial LC filter is selected for further experimentation. An extensive set of experiments are carried out in order to validate the proposed solution for being used on remote handling equipment at ITER.

Intraspinal cell transplantation for targeting cervical ventral horn in amyotrophic lateral sclerosis and traumatic spinal cord injury.

Science.gov (United States)

Lepore, Angelo C

2011-09-18

Respiratory compromise due to phrenic motor neuron loss is a debilitating consequence of a large proportion of human traumatic spinal cord injury (SCI) cases (1) and is the ultimate cause of death in patients with the motor neuron disorder, amyotrophic laterals sclerosis (ALS) (2). ALS is a devastating neurological disorder that is characterized by relatively rapid degeneration of upper and lower motor neurons. Patients ultimately succumb to the disease on average 2-5 years following diagnosis because of respiratory paralysis due to loss of phrenic motor neuron innnervation of the diaphragm (3). The vast majority of cases are sporadic, while 10% are of the familial form. Approximately twenty percent of familial cases are linked to various point mutations in the Cu/Zn superoxide dismutase 1 (SOD1) gene on chromosome 21 (4). Transgenic mice (4,5) and rats (6) carrying mutant human SOD1 genes ((G93A, G37R, G86R, G85R)) have been generated, and, despite the existence of other animal models of motor neuron loss, are currently the most highly used models of the disease. Spinal cord injury (SCI) is a heterogeneous set of conditions resulting from physical trauma to the spinal cord, with functional outcome varying according to the type, location and severity of the injury (7). Nevertheless, approximately half of human SCI cases affect cervical regions, resulting in debilitating respiratory dysfunction due to phrenic motor neuron loss and injury to descending bulbospinal respiratory axons (1). A number of animal models of SCI have been developed, with the most commonly used and clinically-relevant being the contusion (8). Transplantation of various classes of neural precursor cells (NPCs) is a promising therapeutic strategy for treatment of traumatic CNS injuries and neurodegeneration, including ALS and SCI, because of the ability to replace lost or dysfunctional CNS cell types, provide neuroprotection, and deliver gene factors of interest (9). Animal models of both ALS and

Understanding the relationship between brain and upper limb function in children with unilateral motor impairments: A multimodal approach

NARCIS (Netherlands)

Weinstein, M.; Green, D.; Rudisch, J.; Zielinski, I.M.; Benthem-Muñiz, M.; Jongsma, M.L.A.; McLellend, V.; Steenbergen, B.; Shiran, S.I.; Ben Bashat, D.; Barker, G.J.

2018-01-01

Atypical brain development and early brain injury have profound and long lasting impact on the development, skill acquisition, and subsequent independence of a child. Heterogeneity is present at the brain level and at the motor level; particularly with respect to phenomena of bilateral activation

Ganzfeld stimulation or sleep enhance long term motor memory consolidation compared to normal viewing in saccadic adaptation paradigm.

Directory of Open Access Journals (Sweden)

Caroline Voges

Full Text Available Adaptation of saccade amplitude in response to intra-saccadic target displacement is a type of implicit motor learning which is required to compensate for physiological changes in saccade performance. Once established trials without intra-saccadic target displacement lead to de-adaptation or extinction, which has been attributed either to extra-retinal mechanisms of spatial constancy or to the influence of the stable visual surroundings. Therefore we investigated whether visual deprivation ("Ganzfeld"-stimulation or sleep can partially maintain this motor learning compared to free viewing of the natural surroundings. Thirty-five healthy volunteers performed two adaptation blocks of 100 inward adaptation trials - interspersed by an extinction block - which were followed by a two-hour break with or without visual deprivation (VD. Using additional adaptation and extinction blocks short and long (4 weeks term memory of this implicit motor learning were tested. In the short term, motor memory tested immediately after free viewing was superior to adaptation performance after VD. In the long run, however, effects were opposite: motor memory and relearning of adaptation was superior in the VD conditions. This could imply independent mechanisms that underlie the short-term ability of retrieving learned saccadic gain and its long term consolidation. We suggest that subjects mainly rely on visual cues (i.e., retinal error in the free viewing condition which makes them prone to changes of the visual stimulus in the extinction block. This indicates the role of a stable visual array for resetting adapted saccade amplitudes. In contrast, visual deprivation (GS and sleep, might train subjects to rely on extra-retinal cues, e.g., efference copy or prediction to remap their internal representations of saccade targets, thus leading to better consolidation of saccadic adaptation.

Electric Motor Thermal Management R&D

Energy Technology Data Exchange (ETDEWEB)

Bennion, Kevin

2016-06-07

Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

Neuroimaging in pre-motor Parkinson's disease

Directory of Open Access Journals (Sweden)

Thomas R. Barber

2017-01-01

Full Text Available The process of neurodegeneration in Parkinson's disease begins long before the onset of clinical motor symptoms, resulting in substantial cell loss by the time a diagnosis can be made. The period between the onset of neurodegeneration and the development of motoric disease would be the ideal time to intervene with disease modifying therapies. This pre-motor phase can last many years, but the lack of a specific clinical phenotype means that objective biomarkers are needed to reliably detect prodromal disease. In recent years, recognition that patients with REM sleep behaviour disorder (RBD are at particularly high risk of future parkinsonism has enabled the development of large prodromal cohorts in which to investigate novel biomarkers, and neuroimaging has generated some of the most promising results to date. Here we review investigations undertaken in RBD and other pre-clinical cohorts, including modalities that are well established in clinical Parkinson's as well as novel imaging methods. Techniques such as high resolution MRI of the substantia nigra and functional imaging of Parkinsonian brain networks have great potential to facilitate early diagnosis. Further longitudinal studies will establish their true value in quantifying prodromal neurodegeneration and predicting future Parkinson's.

Midcervical neuronal discharge patterns during and following hypoxia

Science.gov (United States)

Sandhu, M. S.; Baekey, D. M.; Maling, N. G.; Sanchez, J. C.; Reier, P. J.

2014-01-01

Anatomical evidence indicates that midcervical interneurons can be synaptically coupled with phrenic motoneurons. Accordingly, we hypothesized that interneurons in the C3–C4 spinal cord can display discharge patterns temporally linked with inspiratory phrenic motor output. Anesthetized adult rats were studied before, during, and after a 4-min bout of moderate hypoxia. Neuronal discharge in C3–C4 lamina I–IX was monitored using a multielectrode array while phrenic nerve activity was extracellularly recorded. For the majority of cells, spike-triggered averaging (STA) of ipsilateral inspiratory phrenic nerve activity based on neuronal discharge provided no evidence of discharge synchrony. However, a distinct STA phrenic peak with a 6.83 ± 1.1 ms lag was present for 5% of neurons, a result that indicates a monosynaptic connection with phrenic motoneurons. The majority (93%) of neurons changed discharge rate during hypoxia, and the diverse responses included both increased and decreased firing. Hypoxia did not change the incidence of STA peaks in the phrenic nerve signal. Following hypoxia, 40% of neurons continued to discharge at rates above prehypoxia values (i.e., short-term potentiation, STP), and cells with initially low discharge rates were more likely to show STP (P phrenic motoneuron pool, and these cells can modulate inspiratory phrenic output. In addition, the C3–C4 propriospinal network shows a robust and complex pattern of activation both during and following an acute bout of hypoxia. PMID:25552641

Monitoring long-lasting insecticidal net (LLIN) durability to validate net serviceable life assumptions, in Rwanda

NARCIS (Netherlands)

Hakizimana, E.; Cyubahiro, B.; Rukundo, A.; Kabayiza, A.; Mutabazi, A.; Beach, R.; Patel, R.; Tongren, J.E.; Karema, C.

2014-01-01

Background To validate assumptions about the length of the distribution–replacement cycle for long-lasting insecticidal nets (LLINs) in Rwanda, the Malaria and other Parasitic Diseases Division, Rwanda Ministry of Health, used World Health Organization methods to independently confirm the three-year

submitter Estimation of stepping motor current from long distances through cable-length-adaptive piecewise affine virtual sensor

CERN Document Server

Oliveri, Alberto; Masi, Alessandro; Storace, Marco

2015-01-01

In this paper a piecewise affine virtual sensor is used for the estimation of the motor-side current of hybrid stepper motors, which actuate the LHC (Large Hadron Collider) collimators at CERN. The estimation is performed starting from measurements of the current in the driver, which is connected to the motor by a long cable (up to 720 m). The measured current is therefore affected by noise and ringing phenomena. The proposed method does not require a model of the cable, since it is only based on measured data and can be used with cables of different length. A circuit architecture suitable for FPGA implementation has been designed and the effects of fixed point representation of data are analyzed.

Detecting the transport of materials with axoplasm along the axon at the early stage after phrenic nerve neurotization via SPECT on a rabbit model

International Nuclear Information System (INIS)

Xu Wendong; Xu Jianguang; Gu Yudong; Jin Shaojin; Lin Xiangtong

2003-01-01

Objective: To study the feasibility of estimating the regenerative quality of transferred phrenic nerve by SPECT. Methods: Two tracers, 131 I-tyrosine and 99 Tc m -methylene diphosphonic acid (MDP) were selected. SPECT compounded with high-energy collimation implement (for 131 I) and low-energy collimation implement (for 99 Tc m ) was used. A rabbit model was set up. 131 I-tyrosine was injected into the normal sciatic nerve and transferred phrenic nerve by micro-syringe. The SPECT scanning was carried out at different intervals. The tracing image of 131 I was used for detecting the material migration along the axon and bone image of 99 Tc m -MDP was used for the bone orientation, these two images were interinfiltrated then. Results: The radioactivity of 131 I-tyrosine could be detected by SPECT, the transportation speed was about 30 mm/d in rabbit's normal sciatic nerve. For phrenic nerve transfer group, the 131 I-tyrosine was transported distally to the anastomotic site along with axoplasm in good regeneration group one month after anastomosis, the transportation speed was 40 mm/d. In scar group, the 131 I-tyrosine was accumulated approximately at the anastomotic site and could not be transported distally. Conclusions: The image of 131 I-tyrosine transported with nerve axoplasm could be displayed by SPECT in vivo. The method could be used to detect the circulation of regenerated axoplasm passing through the anastomotic site at the early stage after nerve transferring operation

The benefits of cholinergic enhancement during perceptual learning are long-lasting

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Ariel eRokem

2013-05-01

Full Text Available The neurotransmitter acetylcholine (ACh regulates many aspects of cognition, including attention and memory. Previous research in animal models has shown that plasticity in sensory systems often depends on the behavioral relevance of a stimulus and/or task. However, experimentally increasing ACh release in the cortex can result in experience-dependent plasticity, even in the absence of behavioral relevance. In humans, the pharmacological enhancement of ACh transmission by administration of the cholinesterase inhibitor donepezil during performance of a perceptual task increases the magnitude of perceptual learning (PL and its specificity to physical parameters of the stimuli used for training. Behavioral effects of PL have previously been shown to persist for many months. In the present study, we tested whether enhancement of PL by donepezil is also long-lasting. Healthy human subjects were trained on a motion direction discrimination task during cholinergic enhancement, and follow-up testing was performed 5-15 months after the end of training and without additional drug administration. Increases in performance associated with training under donepezil were evident in follow-up retesting, indicating that cholinergic enhancement has beneficial long-term effects on PL. These findings suggest that cholinergic enhancement of training procedures used to treat clinical disorders should improve long-term outcomes of these procedures.

Diaphragmatic reinnervation in ventilator-dependent patients with cervical spinal cord injury and concomitant phrenic nerve lesions using simultaneous nerve transfers and implantable neurostimulators.

Science.gov (United States)

Kaufman, Matthew R; Elkwood, Andrew I; Aboharb, Farid; Cece, John; Brown, David; Rezzadeh, Kameron; Jarrahy, Reza

2015-06-01

Patients who are ventilator dependent as a result of combined cervical spinal cord injury and phrenic nerve lesions are generally considered to be unsuitable candidates for diaphragmatic pacing due to loss of phrenic nerve integrity and denervation of the diaphragm. There is limited data regarding efficacy of simultaneous nerve transfers and diaphragmatic pacemakers in the treatment of this patient population. A retrospective review was conducted of 14 consecutive patients with combined lesions of the cervical spinal cord and phrenic nerves, and with complete ventilator dependence, who were treated with simultaneous microsurgical nerve transfer and implantation of diaphragmatic pacemakers. Parameters of interest included time to recovery of diaphragm electromyographic activity, average time pacing without the ventilator, and percent reduction in ventilator dependence. Recovery of diaphragm electromyographic activity was demonstrated in 13 of 14 (93%) patients. Eight of these 13 (62%) patients achieved sustainable periods (> 1 h/d) of ventilator weaning (mean = 10 h/d [n = 8]). Two patients recovered voluntary control of diaphragmatic activity and regained the capacity for spontaneous respiration. The one patient who did not exhibit diaphragmatic reinnervation remains within 12 months of initial treatment. Surgical intervention resulted in a 25% reduction (p nerve transfers and pacemaker implantation can result in reinnervation of the diaphragm and lead to successful ventilator weaning. Our favorable outcomes support consideration of this surgical method for appropriate patients who would otherwise have no alternative therapy to achieve sustained periods of ventilator independence. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Surgical outcomes following nerve transfers in upper brachial plexus injuries

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Bhandari P

2009-01-01

Full Text Available Background: Brachial plexus injuries represent devastating injuries with a poor prognosis. Neurolysis, nerve repair, nerve grafts, nerve transfer, functioning free-muscle transfer and pedicle muscle transfer are the main surgical procedures for treating these injuries. Among these, nerve transfer or neurotization is mainly indicated in root avulsion injury. Materials and Methods: We analysed the results of various neurotization techniques in 20 patients (age group 20-41 years, mean 25.7 years in terms of denervation time, recovery time and functional results. The inclusion criteria for the study included irreparable injuries to the upper roots of brachial plexus (C5, C6 and C7 roots in various combinations, surgery within 10 months of injury and a minimum follow-up period of 18 months. The average denervation period was 4.2 months. Shoulder functions were restored by transfer of spinal accessory nerve to suprascapular nerve (19 patients, and phrenic nerve to suprascapular nerve (1 patient. In 11 patients, axillary nerve was also neurotized using different donors - radial nerve branch to the long head triceps (7 patients, intercostal nerves (2 patients, and phrenic nerve with nerve graft (2 patients. Elbow flexion was restored by transfer of ulnar nerve motor fascicle to the motor branch of biceps (4 patients, both ulnar and median nerve motor fascicles to the biceps and brachialis motor nerves (10 patients, spinal accessory nerve to musculocutaneous nerve with an intervening sural nerve graft (1 patient, intercostal nerves (3rd, 4th and 5th to musculocutaneous nerve (4 patients and phrenic nerve to musculocutaneous nerve with an intervening graft (1 patient. Results: Motor and sensory recovery was assessed according to Medical Research Council (MRC Scoring system. In shoulder abduction, five patients scored M4 and three patients M3+. Fair results were obtained in remaining 12 patients. The achieved abduction averaged 95 degrees (range, 50 - 170

Ipilimumab in advanced melanoma: reports of long-lasting responses.

Science.gov (United States)

Farolfi, Alberto; Ridolfi, Laura; Guidoboni, Massimo; Nicoletti, Stefania Vittoria Luisa; Piciucchi, Sara; Valmorri, Linda; Costantini, Matteo; Scarpi, Emanuela; Amadori, Dino; Ridolfi, Ruggero

2012-06-01

Patients with metastatic melanoma have a poor prognosis; the results of chemotherapy remain unsatisfactory. Ipilimumab, an anticytotoxic T lymphocyte-associated antigen-4 antibody, has shown promising results in several clinical trials. In this report, advanced melanoma patients receiving ipilimumab were scored according to novel immune-related response criteria (irRC) in an attempt to capture additional response patterns and to avoid premature treatment cessation. Thirty-six heavily pretreated metastatic melanoma patients recieved ipilimumab within five international clinical trials at our Institution from May 2006 to August 2008. Disease progression was defined as an increase in tumor burden by at least 25% compared with the nadir, irrespective of any initial increase in baseline lesions or the appearance of new lesions. We report unusually long-lasting responses in patients treated with ipilimumab 10 mg/kg. An overall response was observed in six out of 30 patients (20%), a complete response in three (10%), and disease control in 11 (37%), which seemed to be of a long duration (median of 16 months; complete response 36+, 34+, and 41+ months). All irRC patterns seemed to be strongly associated with an improvement in overall survival. Interestingly, we found a correlation between the presence of a grade 3/4 immune-related adverse event and responses, time to progression, and overall survival. Ipilimumab therapy resulted in clinically meaningful responses in advanced melanoma patients, supporting the need for further irRC validation.

Unique Phrenic Nerve-Sparing Regional Anesthetic Technique for Pain Management after Shoulder Surgery

Directory of Open Access Journals (Sweden)

Jason K. Panchamia

2017-01-01

Full Text Available Background. Ipsilateral phrenic nerve blockade is a common adverse event after an interscalene brachial plexus block, which can result in respiratory deterioration in patients with preexisting pulmonary conditions. Diaphragm-sparing nerve block techniques are continuing to evolve, with the intention of providing satisfactory postoperative analgesia while minimizing hemidiaphragmatic paralysis after shoulder surgery. Case Report. We report the successful application of a combined ultrasound-guided infraclavicular brachial plexus block and suprascapular nerve block in a patient with a complicated pulmonary history undergoing a total shoulder replacement. Conclusion. This case report briefly reviews the important innervations to the shoulder joint and examines the utility of the infraclavicular brachial plexus block for postoperative pain management.

Long lasting clinical response to chemotherapy for advanced uterine leiomyosarcoma: a case report.

Science.gov (United States)

Ridolfi, Claudio; Pasini, Giuseppe; Drudi, Fabrizio; Barzotti, Eleonora; Santelmo, Carlotta; Polselli, Antonio; Ravaioli, Alberto

2013-01-24

Uterine leiomyosarcoma is one of the most frequent uterine sarcomas. In the metastatic setting it is sensitive to doxorubicin, ifosfamide, gemcitabine, docetaxel and a few other drugs, but time to progression is generally short. For this reason prognosis is often poor and there are few reports in the literature of long responders. We report a case of a 40-year-old Caucasian woman with metastatic uterine leiomyosarcoma who began treatment six years before the presentation of this case report and for the following six years underwent ten lines of chemotherapy, achieving excellent results and a good quality of life. Among the treatments administered we observed a long response to temolozomide, an unconventional drug for this kind of disease. Although there are few chemotherapeutic options for the management of metastatic uterine leiomyosarcoma, a small number of patients have an unexpected long lasting response to treatment. For this reason further research is needed to identify new therapeutic agents and the predictive factors for the achievement of response.

Long-lasting pathological consequences of overexpression-induced α-synuclein spreading in the rat brain.

Science.gov (United States)

Rusconi, Raffaella; Ulusoy, Ayse; Aboutalebi, Helia; Di Monte, Donato A

2018-04-01

Increased expression of α-synuclein can initiate its long-distance brain transfer, representing a potential mechanism for pathology spreading in age-related synucleinopathies, such as Parkinson's disease. In this study, the effects of overexpression-induced α-synuclein transfer were assessed over a 1-year period after injection of viral vectors carrying human α-synuclein DNA into the rat vagus nerve. This treatment causes targeted overexpression within neurons in the dorsal medulla oblongata and subsequent diffusion of the exogenous protein toward more rostral brain regions. Protein advancement and accumulation in pontine, midbrain, and forebrain areas were contingent upon continuous overexpression, because death of transduced medullary neurons resulted in cessation of spreading. Lack of sustained spreading did not prevent the development of long-lasting pathological changes. Particularly remarkable were findings in the locus coeruleus, a pontine nucleus with direct connections to the dorsal medulla oblongata and greatly affected by overexpression-induced transfer in this model. Data revealed progressive degeneration of catecholaminergic neurons that proceeded long beyond the time of spreading cessation. Neuronal pathology in the locus coeruleus was accompanied by pronounced microglial activation and, at later times, astrocytosis. Interestingly, microglial activation was also featured in another region reached by α-synuclein transfer, the central amygdala, even in the absence of frank neurodegeneration. Thus, overexpression-induced spreading, even if temporary, causes long-lasting pathological consequences in brain regions distant from the site of overexpression but anatomically connected to it. Neurodegeneration may be a consequence of severe protein burden, whereas even a milder α-synuclein accumulation in tissues affected by protein transfer could induce sustained microglial activation. © 2018 The Authors. Aging Cell published by the Anatomical Society and

A Case of Death Secondary to Phrenic Nerve Palsy after Huge Mediastinal Teratoma 
Resection in Newborn

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Yuanda CHENG

2015-08-01

Full Text Available Neonatal teratomas, not common in clinical, are often some case reports, female more than male, most are benign. It can occur anywhere of body midline; sacrococcygeal teratoma is the most common and the second most frequent site of extragonadal teratomas is mediastinum. Benign is more commom and malignant is very rarely seen. Completely surgical resection is the main and effective treatment. This review reports a case of neonatal teratoma, which is complicated with a fatal phrenic nerve palsy after surgery.

Short-Term, Intermittent Fasting Induces Long-Lasting Gut Health and TOR-Independent Lifespan Extension.

Science.gov (United States)

Catterson, James H; Khericha, Mobina; Dyson, Miranda C; Vincent, Alec J; Callard, Rebecca; Haveron, Steven M; Rajasingam, Arjunan; Ahmad, Mumtaz; Partridge, Linda

2018-06-04

Intermittent fasting (IF) can improve function and health during aging in laboratory model organisms, but the mechanisms at work await elucidation. We subjected fruit flies (Drosophila melanogaster) to varying degrees of IF and found that just one month of a 2-day fed:5-day fasted IF regime at the beginning of adulthood was sufficient to extend lifespan. This long-lasting, beneficial effect of early IF was not due to reduced fecundity. Starvation resistance and resistance to oxidative and xenobiotic stress were increased after IF. Early-life IF also led to higher lipid content in 60-day-old flies, a potential explanation for increased longevity. Guts of flies 40 days post-IF showed a significant reduction in age-related pathologies and improved gut barrier function. Improved gut health was also associated with reduced relative bacterial abundance. Early IF thus induced profound long-term changes. Pharmacological and genetic epistasis analysis showed that IF acted independently of the TOR pathway because rapamycin and IF acted additively to extend lifespan, and global expression of a constitutively active S6K did not attenuate the IF-induced lifespan extension. We conclude that short-term IF during early life can induce long-lasting beneficial effects, with robust increase in lifespan in a TOR-independent manner, probably at least in part by preserving gut health. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Piezoelectric Motors, an Overview

OpenAIRE

Karl Spanner; Burhanettin Koc

2016-01-01

Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ult...

Estimating the relevance of world disturbances to explain savings, interference and long-term motor adaptation effects.

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Max Berniker

2011-10-01

Full Text Available Recent studies suggest that motor adaptation is the result of multiple, perhaps linear processes each with distinct time scales. While these models are consistent with some motor phenomena, they can neither explain the relatively fast re-adaptation after a long washout period, nor savings on a subsequent day. Here we examined if these effects can be explained if we assume that the CNS stores and retrieves movement parameters based on their possible relevance. We formalize this idea with a model that infers not only the sources of potential motor errors, but also their relevance to the current motor circumstances. In our model adaptation is the process of re-estimating parameters that represent the body and the world. The likelihood of a world parameter being relevant is then based on the mismatch between an observed movement and that predicted when not compensating for the estimated world disturbance. As such, adapting to large motor errors in a laboratory setting should alert subjects that disturbances are being imposed on them, even after motor performance has returned to baseline. Estimates of this external disturbance should be relevant both now and in future laboratory settings. Estimated properties of our bodies on the other hand should always be relevant. Our model demonstrates savings, interference, spontaneous rebound and differences between adaptation to sudden and gradual disturbances. We suggest that many issues concerning savings and interference can be understood when adaptation is conditioned on the relevance of parameters.

Neonatal oxytocin manipulations have long-lasting, sexually dimorphic effects on vasopressin receptors.

Science.gov (United States)

Bales, K L; Plotsky, P M; Young, L J; Lim, M M; Grotte, N; Ferrer, E; Carter, C S

2007-01-05

Developmental exposure to oxytocin (OT) or oxytocin antagonists (OTAs) has been shown to cause long-lasting and often sexually dimorphic effects on social behaviors in prairie voles (Microtus ochrogaster). Because regulation of social behavior in monogamous mammals involves central receptors for OT, arginine vasopressin (AVP), and dopamine, we examined the hypothesis that the long-lasting, developmental effects of exposure to neonatal OT or OTA might reflect changes in the expression of receptors for these peptides. On postnatal day 1, prairie voles were injected intraperitoneally with either OT (1 mg/kg), an OTA (0.1 mg/kg), saline vehicle, or were handled only. At approximately 60 days of age, vasopressin V1a receptors, OT receptors (OTR) and dopamine D2 receptor binding were quantified using receptor autoradiography in brain tissue taken from males and females. Significant treatment effects on V1a binding were found in the bed nucleus of the stria terminalis (BNST), cingulate cortex (CgCtx), mediodorsal thalamus (MdThal), medial preoptic area of the hypothalamus (MPOA), and lateral septum (LS). The CgCtx, MPOA, ventral pallidum, and LS also showed significant sex by treatment interactions on V1a binding. No significant treatment or sex differences were observed for D2 receptor binding. No significant treatment difference was observed for OTR receptor binding, and only a marginal sex difference. Changes in the neuropeptide receptor expression, especially the V1a receptor, may help to explain sexually dimorphic changes in behavior that follow comparable neonatal manipulations.

Relationship between diffusion tensor fractional anisotropy and long-term motor outcome in patients with hemiparesis after middle cerebral artery infarction.

Science.gov (United States)

Koyama, Tetsuo; Marumoto, Kohei; Miyake, Hiroji; Domen, Kazuhisa

2014-10-01

Magnetic resonance diffusion tensor fractional anisotropy (DTI-FA) is often used to characterize neural damage after stroke. Here we assessed the relationship between DTI-FA and long-term motor outcome in patients after middle cerebral artery (MCA) infarction. Fractional anisotropy (FA) maps were generated from diffusion tensor brain images obtained from 16 patients 14-18 days postinfarction, and tract-based spatial statistics (TBSS) analysis was applied. Regions of interest were set within the right and left corticospinal tracts, and mean FA values were extracted from individual TBSS data. Hemiparesis motor outcome was evaluated according to Brunnstrom stage (BRS: 1-6, severe-normal) for separate shoulder/elbow/forearm, hand, and lower extremity functions, as well as the motor component score of the Functional Independence Measure (FIM-motor: 13-91, null-full) 5-7 months after onset. Ratios between FA values in the affected and unaffected hemispheres (rFA) were assessed by BRS and FIM-motor scores. rFA values were .636-.984 (median, .883) and BRS scores were 1-6 (median, 3) for shoulder/elbow/forearm, 2-6 (median, 3) for hand, and 3-6 (median, 5) for the lower extremities. FIM-motor scores were 51-90 (median, 75). Analysis revealed significant relationships between rFA and BRS data (correlation coefficient: .687 for shoulder/elbow/forearm, .579 for hand, and .623 for lower extremities) but no significance relationship between rFA and FIM-motor scores. The results suggest that DTI-FA is applicable for predicting the long-term outcome of extremity functions after MCA infarction. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Short and long-lasting behavioral consequences of agonistic encounters between male Drosophila melanogaster.

Science.gov (United States)

Trannoy, Séverine; Penn, Jill; Lucey, Kenia; Popovic, David; Kravitz, Edward A

2016-04-26

In many animal species, learning and memory have been found to play important roles in regulating intra- and interspecific behavioral interactions in varying environments. In such contexts, aggression is commonly used to obtain desired resources. Previous defeats or victories during aggressive interactions have been shown to influence the outcome of later contests, revealing loser and winner effects. In this study, we asked whether short- and/or long-term behavioral consequences accompany victories and defeats in dyadic pairings between male Drosophila melanogaster and how long those effects remain. The results demonstrated that single fights induced important behavioral changes in both combatants and resulted in the formation of short-term loser and winner effects. These decayed over several hours, with the duration depending on the level of familiarity of the opponents. Repeated defeats induced a long-lasting loser effect that was dependent on de novo protein synthesis, whereas repeated victories had no long-term behavioral consequences. This suggests that separate mechanisms govern the formation of loser and winner effects. These studies aim to lay a foundation for future investigations exploring the molecular mechanisms and circuitry underlying the nervous system changes induced by winning and losing bouts during agonistic encounters.

Modulation of motor performance and motor learning by transcranial direct current stimulation.

Science.gov (United States)

Reis, Janine; Fritsch, Brita

2011-12-01

Transcranial direct current stimulation (tDCS) has shown preliminary success in improving motor performance and motor learning in healthy individuals, and restitution of motor deficits in stroke patients. This brief review highlights some recent work. Within the past years, behavioural studies have confirmed and specified the timing and polarity specific effects of tDCS on motor skill learning and motor adaptation. There is strong evidence that timely co-application of (hand/arm) training and anodal tDCS to the contralateral M1 can improve motor learning. Improvements in motor function as measured by clinical scores have been described for combined tDCS and training in stroke patients. For this purpose, electrode montages have been modified with respect to interhemispheric imbalance after brain injury. Cathodal tDCS applied to the unlesioned M1 or bihemispheric M1 stimulation appears to be well tolerated and useful to induce improvements in motor function. Mechanistic studies in humans and animals are discussed with regard to physiological motor learning. tDCS is well tolerated, easy to use and capable of inducing lasting improvements in motor function. This method holds promise for the rehabilitation of motor disabilities, although acute studies in patients with brain injury are so far lacking.

The role of Sema3–Npn-1 signaling during diaphragm innervation and muscle development

Science.gov (United States)

Huettl, Rosa-Eva; Hanuschick, Philipp; Amend, Anna-Lena; Alberton, Paolo; Aszodi, Attila; Huber, Andrea B.

2016-01-01

ABSTRACT Correct innervation of the main respiratory muscle in mammals, namely the thoracic diaphragm, is a crucial pre-requisite for the functionality of this muscle and the viability of the entire organism. Systemic impairment of Sema3A–Npn-1 (Npn-1 is also known as NRP1) signaling causes excessive branching of phrenic nerves in the diaphragm and into the central tendon region, where the majority of misguided axons innervate ectopic musculature. To elucidate whether these ectopic muscles are a result of misguidance of myoblast precursors due to the loss of Sema3A–Npn-1 signaling, we conditionally ablated Npn-1 in somatic motor neurons, which led to a similar phenotype of phrenic nerve defasciculation and, intriguingly, also formation of innervated ectopic muscles. We therefore hypothesize that ectopic myocyte fusion is caused by additional factors released by misprojecting growth cones. Slit2 and its Robo receptors are expressed by phrenic motor axons and migrating myoblasts, respectively, during innervation of the diaphragm. In vitro analyses revealed a chemoattractant effect of Slit2 on primary diaphragm myoblasts. Thus, we postulate that factors released by motor neuron growth cones have an influence on the migration properties of myoblasts during establishment of the diaphragm. PMID:27466379

Long-lasting antifog plasma modification of transparent plastics.

Science.gov (United States)

Di Mundo, Rosa; d'Agostino, Riccardo; Palumbo, Fabio

2014-10-08

Antifog surfaces are necessary for any application requiring optical efficiency of transparent materials. Surface modification methods aimed toward increasing solid surface energy, even when supposed to be permanent, in fact result in a nondurable effect due to the instability in air of highly hydrophilic surfaces. We propose the strategy of combining a hydrophilic chemistry with a nanotextured topography, to tailor a long-lasting antifog modification on commercial transparent plastics. In particular, we investigated a two-step process consisting of self-masked plasma etching followed by plasma deposition of a silicon-based film. We show that the deposition of the silicon-based coatings on the flat (pristine) substrates allows a continuous variation of wettability from hydrophobic to superhydrophilic, due to a continuous reduction of carbon-containing groups, as assessed by Fourier transform infrared and X-ray photoelectron spectroscopies. By depositing these different coatings on previously nanotextured substrates, the surface wettability behavior is changed consistently, as well as the condensation phenomenon in terms of microdroplets/liquid film appearance. This variation is correlated with advancing and receding water contact angle features of the surfaces. More importantly, in the case of the superhydrophilic coating, though its surface energy decreases with time, when a nanotextured surface underlies it, the wetting behavior is maintained durably superhydrophilic, thus durably antifog.

[Long-term clinical course of sequelae in patients with neonatal anoxic encephalopathy resulting in profound mental retardation and motor disturbance].

Science.gov (United States)

Ishizaki, A; Kubota, M; Fueki, N; Shinozaki, M; Kurata, K; Takei, M; Sakamoto, K

1993-01-01

A long-term observation has been made in 58 patients (30 males and 28 females) with severe sequelae of neonatal anoxic encephalopathy. They aged from 8 months to 65 years. All of them had motor disturbances and profound mental retardation. Motor function was improved in 4 patients with aging. In contrast, motor activity deteriorated in 11 cases, of which 4 showed a mental regression. Among them, patients who had originally better motor ability than sitting were likely to deteriorate by uncontrollable epilepsy and/or excessive administration of anticonvulsants. Regression of the patients with worse motor ability like bedridden appeared to attributable hypertonia of muscles and bodily deformation. Fifteen cases showed an exacerbation of general condition which originated predominantly to respiratory distress. Twelve patients died including 6 exacerbated cases. Exacerbation or death may have occurred frequently in specific periods of infancy, adolescence and youth with the patients who showed very low motor function such as bedridden and no locomotion.

Blue photoluminescence and long lasting phosphorescence properties of a novel chloride phosphate phosphor: Sr5(PO4)3Cl:Eu2+

International Nuclear Information System (INIS)

Wu, Chuanqiang; Zhang, Jiachi; Feng, Pengfei; Duan, Yiming; Zhang, Zhiya; Wang, Yuhua

2014-01-01

A novel blue emitting long lasting phosphorescence phosphor Sr 5 (PO 4 ) 3 Cl:Eu 2+ is synthesized by solid state method at 1223 K in reducing atmosphere. The afterglow emission spectrum shows one broad band centered at 441 nm due to the 5d–4f transition of Eu 2+ at six coordinated Sr(II) sites and the color coordinates are calculated to be (0.149, 0.095) which is close to the light blue region. The excitation band is in 240–430 nm and partly overlaps the solar irradiation on Earth's surface. The long lasting phosphorescence of the optimal sample doping by 0.1 mol%Eu 2+ can be recorded for about 1040 s (0.32 mcd/m 2 ). Thermoluminescence shows that there are at least three types of traps corresponding to peaks at 340 K, 382 K, 500 K, respectively. The filling and fading experiments reveal that the traps in Sr 5 (PO 4 ) 3 Cl:Eu 2+ are independent. The shallow traps (340 K) essentially contribute to the visible long lasting phosphorescence, while the deep traps (382 K and 500 K) are proved to be very stable. Thus, the Sr 5 (PO 4 ) 3 Cl:Eu 2+ material shows potential applications as not only a long lasting phosphorescence phosphor, but also an optical storage material. -- Highlights: • The blue long lasting phosphorescence of Sr 5 (PO 4 ) 3 Cl:Eu 2+ is first reported. • Filling and fading experiments are carried out for revealing natures of traps. • The afterglow mechanism for independent traps of Sr 5 (PO 4 ) 3 Cl:Eu 2+ is proposed

A randomised, controlled, double-blind trial of ultrasound-guided phrenic nerve block to prevent shoulder pain after thoracic surgery.

Science.gov (United States)

Blichfeldt-Eckhardt, M R; Laursen, C B; Berg, H; Holm, J H; Hansen, L N; Ørding, H; Andersen, C; Licht, P B; Toft, P

2016-12-01

Moderate to severe ipsilateral shoulder pain is a common complaint following thoracic surgery. In this prospective, parallel-group study at Odense University Hospital, 76 patients (aged > 18 years) scheduled for lobectomy or pneumonectomy were randomised 1:1 using a computer-generated list to receive an ultrasound-guided supraclavicular phrenic nerve block with 10 ml ropivacaine or 10 ml saline (placebo) immediately following surgery. A nerve catheter was subsequently inserted and treatment continued for 3 days. The study drug was pharmaceutically pre-packed in sequentially numbered identical vials assuring that all participants, healthcare providers and data collectors were blinded. The primary outcome was the incidence of unilateral shoulder pain within the first 6 h after surgery. Pain was evaluated using a numeric rating scale. Nine of 38 patients in the ropivacaine group and 26 of 38 patients in the placebo group experienced shoulder pain during the first 6 h after surgery (absolute risk reduction 44% (95% CI 22-67%), relative risk reduction 65% (95% CI 41-80%); p = 0.00009). No major complications, including respiratory compromise or nerve injury, were observed. We conclude that ultrasound-guided supraclavicular phrenic nerve block is an effective technique for reducing the incidence of ipsilateral shoulder pain after thoracic surgery. © 2016 The Association of Anaesthetists of Great Britain and Ireland.

Involvement of high plasma corticosterone status and activation of brain regional serotonin metabolism in long-term erythrosine-induced rearing motor hyper activity in young adult male rats.

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Dalal, Arindam; Poddar, Mrinal K

2010-07-01

Long-term consumption of artificial food color(s) can induce behavioral hyperactivity in human and experimental animals, but no neurobiochemical mechanism is defined. This study investigates the role of brain regional serotonin metabolism including its turnover, MAO-A activity, and plasma corticosterone status in relation to behavioral disturbances due to an artificial food color, erythrosine. Long-term (15 or 30 consecutive days) erythrosine administration with higher dosage (10 or 100 mg/kg/day, p.o.) produced optimal hyperactive state in exploratory behavior (rearing motor activity) after 2 h of last erythrosine administration, in young adult male albino rats. Erythrosine-induced stimulation in brain regional (medulla-pons, hypothalamus, hippocampus, and corpus striatum) serotonin metabolism (measuring steady state levels of 5-HT and 5-HIAA, MAO-A activity), including its turnover (pargyline-induced 5-HT accumulation and 5-HIAA declination rate), as well as plasma corticosterone were also observed depending on dosage(s) and duration(s) of erythrosine administration under similar experimental conditions. The lower dosage of erythrosine (1 mg/kg/day, p.o.) under similar conditions did not affect either of the above. These findings suggests (a) the induction as well as optimal effect of long-term erythrosine (artificial food color) on behavioral hyperactivity in parallel with increase in 5-HT level in brain regions, (b) the activation of brain regional serotonin biosynthesis in accordance with plasma corticosterone status under such behavioral hyperactivity, and (c) a possible inhibitory influence of the enhanced glucocorticoids-serotonin interaction on erythrosine-induced rearing motor hyperactivity in young adult mammals.

Using non-invasive brain stimulation to augment motor training-induced plasticity

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Pascual-Leone Alvaro

2009-03-01

Full Text Available Abstract Therapies for motor recovery after stroke or traumatic brain injury are still not satisfactory. To date the best approach seems to be the intensive physical therapy. However the results are limited and functional gains are often minimal. The goal of motor training is to minimize functional disability and optimize functional motor recovery. This is thought to be achieved by modulation of plastic changes in the brain. Therefore, adjunct interventions that can augment the response of the motor system to the behavioural training might be useful to enhance the therapy-induced recovery in neurological populations. In this context, noninvasive brain stimulation appears to be an interesting option as an add-on intervention to standard physical therapies. Two non-invasive methods of inducing electrical currents into the brain have proved to be promising for inducing long-lasting plastic changes in motor systems: transcranial magnetic stimulation (TMS and transcranial direct current stimulation (tDCS. These techniques represent powerful methods for priming cortical excitability for a subsequent motor task, demand, or stimulation. Thus, their mutual use can optimize the plastic changes induced by motor practice, leading to more remarkable and outlasting clinical gains in rehabilitation. In this review we discuss how these techniques can enhance the effects of a behavioural intervention and the clinical evidence to date.

Alcohol hangover: type and time-extension of motor function impairments.

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Karadayian, Analía G; Cutrera, Rodolfo A

2013-06-15

Alcohol hangover is defined as the unpleasant next-day state following an evening of excessive alcohol consumption. Hangover begins when ethanol is absent in plasma and is characterized by physical and psychological symptoms. During hangover cognitive functions and subjective capacities are affected along with inefficiency, reduced productivity, absenteeism, driving impairments, poor academic achievement and reductions in motor coordination. The aim of this work was to study the type and length of motor and exploratory functions from the beginning to the end of the alcohol hangover. Male Swiss mice were injected i.p. either with saline (control group) or with ethanol (3.8 g/kg BW) (hangover group). Motor performance, walking deficiency, motor strength, locomotion and exploratory activity were evaluated at a basal point (ZT0) and every 2 h up to 20 h after blood alcohol levels were close to zero (hangover onset). Motor performance was 80% decreased at the onset of hangover (pwalking deficiencies from the beginning to 16 h after hangover onset (popen field test and the exploratory activity on T-maze and hole board tests were reduced during 16 h after hangover onset (ptime-extension between 16 to 20 h for hangover motor and exploratory impairments. As a whole, this study shows the long lasting effects of alcohol hangover. Copyright © 2013 Elsevier B.V. All rights reserved.

Low-frequency stimulation cancels the high-frequency-induced long-lasting effects in the rat medial vestibular nuclei.

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Grassi, S; Pettorossi, V E; Zampolini, M

1996-05-15

In rat brainstem slices, we investigated the effects of low-frequency stimulation (LFS) of the primary vestibular afferents on the amplitude of the field potentials evoked in the medial vestibular nuclei (MVN). LFS induced long-term effects, the sign of which depended on whether the vestibular neurons were previously conditioned by HFS. In unconditioned slices, LFS evoked modifications of the responses that were similar to those observed after HFS but had a smaller extension. In fact, LFS caused long-lasting potentiation of the N1 wave in the MVN ventral portion (Vp) and long-lasting depression of the N2 wave in the MVN dorsal portion (Dp), whereas it provoked small and variable effects on the N1 wave. By contrast, when the synaptic transmission was already conditioned, LFS influenced the synaptic responses oppositely, reducing or annulling the HFS long-term effects. This phenomenon was specifically induced by LFS, because HFS was not able to cause it. The involvement of NMDA receptors in mediating the LFS long-term effects was supported by the fact that AP-5 prevented their induction. In addition, the annulment of HFS long-term effects by LFS was also demonstrated by the shift in the latency of the evoked unitary potentials after LFS. In conclusion, we suggest that the reduction of the previously induced conditioning could represent a cancellation mechanism, useful to quickly adapt the vestibular system to continuous different needs and to avoid saturation.

Ventilator waveforms on anesthesia machine: a simple tool for intraoperative mapping of phrenic nerve and mid-cervical roots.

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Georgoulis, George; Papagrigoriou, Eirini; Sindou, Marc

2015-12-01

A crucial aspect of surgery on the supraclavicular region, lateral neck, and mid-cervical vertebral region is the identification and sparing of the phrenic nerve and cervical (C4) root that are responsible for diaphragmatic innervation. Therefore intraoperative mapping of these nerve structures can be useful for difficult cases. Electrical stimulation with simultaneous observation of the ventilator waveforms of the anesthesia machine provides an effective method for the precise intraoperative mapping of these structures. In the literature, there is only one publication reporting the use of one of the waveforms (capnography) for this purpose. Capnography and pressure-time waveforms, two mandatory curves in anesthesiological monitoring, were studied under electrical stimulation of the phrenic nerve (one patient) and the C4 root (eight patients). The aim was to detect changes that would verify diaphragmatic contraction. No modifications in anesthesia or surgery and no additional maneuvers were required. In all patients, stimulation was followed by identifiable changes in the two waveforms, compatible with diaphragmatic contraction: acute reduction in amplitude on capnography and repetitive saw-like elevations on pressure-time curve. Frequency of patterns on pressure-time curve coincided with the frequency of stimulation; therefore the two recordings were complementary. This simple method proved effective in identifying the neural structures responsible for diaphragmatic function. We therefore suggest that it should be employed in the various types of surgery where these structures are at risk.

Comparative study on the analgesic effect of acute ipsilateral shoulder pain after open thoracotomy between preoperative ultrasound guided suprascapular nerve block (SNB) and intraoperative phrenic nerve infiltration (PNI) in cancer lung patients.

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Elfokery, Bassel M; Tawfic, Sahar A; Abdelrahman, Abdelrahman M; Abbas, Dina N; Abdelghaffar, Ikramy M

2018-03-01

Acute ipsilateral shoulder pain (ISP) is a common complaint in patients after thoracotomy. The incidence ranges from 21% to 97%. Unfortunately, clinical studies did not put enough focus on ISP post thoracic surgery. This study was designed to compare the effectiveness of suprascapular nerve block (SNB) and phrenic nerve infiltration (PNI) for controlling ISP. One hundred and thirty-five lung cancer patients (135) scheduled for open-lung surgery were randomly allocated into three equal groups; control group: received thoracic epidural with general anesthesia, suprascapular group: (SNB) one hour before the operation with 10 ml bupivacaine plus thoracic epidural with general anesthesia and phrenic nerve group: (PNI) was performed by the operating surgeon with 10 ml bupivacaine plus thoracic epidural with general anesthesia. The visual analogue score (VAS) of ISP, rescue of ketorolac for break through shoulder pain, peak expiratory flow rate (PEFR) and arterial blood gases were measured every 6 h postoperatively for 48 h. The VAS, rescue doses of ketorolc and PEFR were significantly lower in the phrenic nerve group (P-value 0.05). PNI is more effective than SNB for ISP. Production and hosting by Elsevier B.V.

Long lasting clinical response to chemotherapy for advanced uterine leiomyosarcoma: a case report

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Ridolfi Claudio

2013-01-01

Full Text Available Abstract Introduction Uterine leiomyosarcoma is one of the most frequent uterine sarcomas. In the metastatic setting it is sensitive to doxorubicin, ifosfamide, gemcitabine, docetaxel and a few other drugs, but time to progression is generally short. For this reason prognosis is often poor and there are few reports in the literature of long responders. Case presentation We report a case of a 40-year-old Caucasian woman with metastatic uterine leiomyosarcoma who began treatment six years before the presentation of this case report and for the following six years underwent ten lines of chemotherapy, achieving excellent results and a good quality of life. Among the treatments administered we observed a long response to temolozomide, an unconventional drug for this kind of disease. Conclusion Although there are few chemotherapeutic options for the management of metastatic uterine leiomyosarcoma, a small number of patients have an unexpected long lasting response to treatment. For this reason further research is needed to identify new therapeutic agents and the predictive factors for the achievement of response.

Phrenic palsy and analgesic quality of continuous supraclavicular vs. interscalene plexus blocks after shoulder surgery.

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Wiesmann, T; Feldmann, C; Müller, H H; Nentwig, L; Beermann, A; El-Zayat, B F; Zoremba, M; Wulf, H; Steinfeldt, T

2016-09-01

Hemidiaphragmatic palsy is a common consequence of the interscalene brachial plexus block. It occurs less commonly with the supraclavicular approach. Register data suggest that the analgesic quality of a supraclavicular blockade is sufficient for arthroscopic shoulder surgery, although data on the post-operative analgesic effect are lacking. After approval by the ethics committee, patients having arthroscopic shoulder surgery under general anaesthesia were randomized to receive a continuous interscalene or supraclavicular blockade. Phrenic nerve function was evaluated through ultrasound examination of the diaphragm in combination with spirometry. Pain scores at rest and activity etc. were determined before catheter insertion, during observation in the post- anaesthesia care unit (PACU) and on post-operative day 1 (POD1). The initial application of 10 ml of ropivacaine 0.2% was followed by continuous application of 4 ml of ropivacaine 0.2%, plus a patient controlled analgesia (PCA) bolus of 4 ml/h. One hundred and twenty patients were randomized, of which 114 data sets were analysed. Complete hemidiaphragmatic paresis occurred in 43% of the interscalene group vs. 24% in the supraclavicular group during PACU stay. Rates of dyspnoea and hoarseness were similar. Horner's syndrome occurred in 21% of the interscalene but only 3% of the supraclavicular group on POD1. Pain scores were comparable for pain at rest and during stress at each time point. This trial showed a significantly greater incidence of phrenic nerve palsy of the interscalene group in PACU, but not on POD1. Post-operative analgesic quality was similar in both groups. Continuous supraclavicular blockade is a suitable alternative to the continuous interscalene technique. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Recent developments in esophageal motor disorders.

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Beaumont, Hanneke; Boeckxstaens, Guy

2007-07-01

Every year more insight into the pathogenesis and treatment of esophageal motor disorders is obtained. This review highlights some interesting literature published in this area during the last year. Longitudinal and circular muscle contractions act in a well coordinated fashion to allow normal peristalsis. Techniques such as intraluminal impedance, high-resolution manometry and intraluminal ultrasound provide useful additional information on esophageal function both in the normal and abnormal situation. The dynamics of the gastroesophageal junction can be studied with a newly developed probe, and the mechanism behind transient lower esophageal sphincter relaxations is still being unravelled. New manometric criteria for nutcracker esophagus have been proposed, whereas further evidence is reported supporting an association between diabetes mellitus and cardiovascular disease and esophageal dysmotility and spasm, respectively. Finally, several long-term follow-up results of surgical myotomy and pneumodilatation have been reported. Due to the perfection of esophageal measuring techniques, our knowledge of esophageal function continues to increase. The studies reviewed here provide interesting information on the pathogenesis and treatment of several esophageal motor disorders.

Epicardial phrenic nerve displacement during catheter ablation of atrial and ventricular arrhythmias: procedural experience and outcomes.

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Kumar, Saurabh; Barbhaiya, Chirag R; Baldinger, Samuel H; Koplan, Bruce A; Maytin, Melanie; Epstein, Laurence M; John, Roy M; Michaud, Gregory F; Tedrow, Usha B; Stevenson, William G

2015-08-01

Arrhythmia origin in close proximity to the phrenic nerve (PN) can hinder successful catheter ablation. We describe our approach with epicardial PN displacement in such instances. PN displacement via percutaneous pericardial access was attempted in 13 patients (age 49±16 years, 9 females) with either atrial tachycardia (6 patients) or atrial fibrillation triggered from a superior vena cava focus (1 patient) adjacent to the right PN or epicardial ventricular tachycardia origin adjacent to the left PN (6 patients). An epicardially placed steerable sheath/4 mm-catheter combination (5 patients) or a vascular or an esophageal balloon (8 patients) was ultimately successful. Balloon placement was often difficult requiring manipulation via a steerable sheath. In 2 ventricular tachycardia cases, absence of PN capture was achieved only once the balloon was directly over the ablation catheter. In 3 atrial tachycardia patients, PN displacement was not possible with a balloon; however, a steerable sheath/catheter combination was ultimately successful. PN displacement allowed acute abolishment of all targeted arrhythmias. No PN injury occurred acutely or in follow up. Two patients developed acute complications (pleuro-pericardial fistula 1 and pericardial bleeding 1). Survival free of target arrhythmia was achieved in all atrial tachycardia patients; however, a nontargeted ventricular tachycardia recurred in 1 patient at a median of 13 months' follow up. Arrhythmias originating in close proximity to the PN can be targeted successfully with PN displacement with an epicardially placed steerable sheath/catheter combination, or balloon, but this strategy can be difficult to implement. Better tools for phrenic nerve protection are desirable. © 2015 American Heart Association, Inc.

Effects of rocuronium and vecuronium on initial rundown of endplate potentials in the isolated phrenic nerve diaphragm preparation of rats

OpenAIRE

Li, Jun; Liu, Yong-Qin; Zhang, Han-Ting

2013-01-01

Rocuronium and vecuronium, two non-depolarizing neuromuscular blockers, have been widely used in surgery procedures. However, their electrophysiological properties need to be more widely explored. We examined the effects of rocuronium and vecuronium on initial rundown of endplate potential amplitudes in the non-uniform stretched muscle preparation of the rat isolated phrenic nerve diaphragm. More specifically, the endplate potentials were recorded with one microelectrode from a single endplat...

Long-lasting effects of maternal condition in free-ranging cervids.

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Eric D Freeman

Full Text Available Causes of phenotypic variation are fundamental to evolutionary ecology because they influence the traits acted upon by natural selection. One such cause of phenotypic variation is a maternal effect, which is the influence of the environment experienced by a female (and her corresponding phenotype on the phenotype of her offspring (independent of the offspring's genotype. While maternal effects are well documented, the longevity and fitness impact of these effects remains unclear because it is difficult to follow free-living individuals through their reproductive lifetimes. For long-lived species, it has been suggested that maternal effects are masked by environmental variables acting on offspring in years following the period of dependence. Our objective was to use indirect measures of maternal condition to determine if maternal effects have long-lasting influences on male offspring in two species of cervid. Because antlers are sexually selected, we used measures of antler size at time of death, 1.5-21.5 years after gestation to investigate maternal effects. We quantified antler size of 11,000 male elk and mule deer born throughout the intermountain western US (6 states over nearly 30 years. Maternal condition during development was estimated indirectly using a suite of abiotic variables known to influence condition of cervids (i.e., winter severity, spring and summer temperature, and spring and summer precipitation. Antler size of male cervids was significantly associated with our indirect measure of maternal condition during gestation and lactation. Assuming the correctness of our indirect measure, our findings demonstrate that antler size is a sexually selected trait that is influenced-into adulthood-by maternal condition. This link emphasizes the importance of considering inherited environmental effects when interpreting population dynamics or examining reproductive success of long-lived organisms.

Esophageal motor disorders: recent advances.

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Dogan, Ibrahim; Mittal, Ravinder K

2006-07-01

The aim of this article is to highlight literature published during the last year in the context of previous knowledge. A number of novel techniques - high-resolution manometry, esophageal electrical impedance and intra-luminal ultrasound imaging - have improved our understanding of esophageal function in health and disease. Several studies address the function of longitudinal muscle layer of the esophagus in normal subjects and patients with motor disorders of the esophagus. Esophageal electrical impedance recordings reveal abnormal transit in patients with diffuse esophageal spasm, achalasia and patients with normal manometry. Loss of the mammalian Sprouty2 gene leads to enteric neuronal hyperplasia and esophageal achalasia. Several studies showed excellent long-term results of medical and surgical treatment of achalasia of the esophagus. For the first time, mechanisms of gastroesophageal reflux in critically ill mechanically ventilated patients are reported. Novel pharmacologic strategies in the treatment of reflux disease are highlighted. Several novel techniques, perfected during recent years, have improved our understanding of esophageal function and dysfunction. A number of important observations, reviewed here, provide important insight into the pathogenesis of esophageal motor disorders and treatment of gastroesophageal reflux disease.

Sleep and Neurofunctions Throughout Child Development: Lasting Effects of Early Iron Deficiency

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Peirano, Patricio D.; Algarín, Cecilia R.; Chamorro, Rodrigo; Garrido, Marcelo I.; Lozoff, Betsy

2013-01-01

Iron-deficiency anemia (IDA) continues to be the most common single nutrient deficiency in the world. Infants are at particular risk due to rapid growth and limited dietary sources of iron. An estimated 20–25% of the world’s infants have IDA, with at least as many having iron deficiency without anemia. High prevalence is found primarily in developing countries, but also among poor, minority, and immigrant groups in developed ones. Infants with IDA test lower in mental and motor development assessments and show affective differences. After iron therapy, follow-up studies point to long-lasting differences in several domains. Neurofunctional studies showed slower neural transmission in the auditory system despite 1 year of iron therapy in IDA infants; they still had slower transmission in both the auditory and visual systems at preschool age. Different motor activity patterning in all sleep-waking states and several differences in sleep states organization were reported. Persistant sleep and neurofunctional effects could contribute to reduced potential for optimal behavioral and cognitive outcomes in children with a history of IDA. PMID:19214058

Prediction of performance in Vasaloppet through long lasting ski- ergometer and rollerski tests in cross-country skiers

DEFF Research Database (Denmark)

Mygind, Erik; Wulff, Kristian; Jensen, Mads Rosenkilde

2015-01-01

-ergometer and Rollerski field tests correlate strongly with performance in Vasaloppet and therefore might be useful test tools for recreational skiers who wish to participate in long lasting c-c competitions. Keywords: Cross-country ski training, Upper body, Exercise intensity, Field test, Body composition blood lactate......The main purpose was to investigate if long lasting cross-country (c-c) test procedures could predict performance time in ‘Vasaloppet’ and secondly the effect of a 16 weeks training period on a 90 min double poling performance test. 24 moderate trained c-c skiers participated in the study...... and completed Vasaloppet. All skiers carried out pre and post training tests in a 90 minutes ski-ergometer double poling test and a 120 minutes rollerski field test on a closed paved circuit. 19 skiers provided detailed training logs that could sufficiently establish their training preparation for Vasaloppet...

Cdk7 Is Required for Activity-Dependent Neuronal Gene Expression, Long-Lasting Synaptic Plasticity and Long-Term Memory

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Guiqin He

2017-11-01

Full Text Available In the brain, de novo gene expression driven by learning-associated neuronal activities is critical for the formation of long-term memories. However, the signaling machinery mediating neuronal activity-induced gene expression, especially the rapid transcription of immediate-early genes (IEGs remains unclear. Cyclin-dependent kinases (Cdks are a family of serine/threonine kinases that have been firmly established as key regulators of transcription processes underling coordinated cell cycle entry and sequential progression in nearly all types of proliferative cells. Cdk7 is a subunit of transcriptional initiation factor II-H (TFIIH and the only known Cdk-activating kinase (CAK in metazoans. Recent studies using a novel Cdk7 specific covalent inhibitor, THZ1, revealed important roles of Cdk7 in transcription regulation in cancer cells. However, whether Cdk7 plays a role in the regulation of transcription in neurons remains unknown. In this study, we present evidence demonstrating that, in post-mitotic neurons, Cdk7 activity is positively correlated with neuronal activities in cultured primary neurons, acute hippocampal slices and in the brain. Cdk7 inhibition by THZ1 significantly suppressed mRNA levels of IEGs, selectively impaired long-lasting synaptic plasticity induced by 4 trains of high frequency stimulation (HFS and prevented the formation of long-term memories.

Piezoelectric Motors, an Overview

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Karl Spanner

2016-02-01

Full Text Available Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ultrasonic motors, inertia-drive, and piezo-walk-drive. In this review, a comprehensive summary of piezoelectric motors, with their classification from initial idea to recent progress, is presented. This review also includes some of the industrial and commercial applications of piezoelectric motors that are presently available in the market as actuators.

Transvenous stimulation of the phrenic nerve for the treatment of central sleep apnoea: 12 months' experience with the remedē® System.

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Jagielski, Dariusz; Ponikowski, Piotr; Augostini, Ralph; Kolodziej, Adam; Khayat, Rami; Abraham, William T

2016-11-01

Patients with central sleep apnoea (CSA) often have poor quality of life and are at increased risk of morbidity and mortality. This study sought to evaluate the 12-month clinical outcomes of patients with CSA treated with unilateral transvenous phrenic nerve stimulation in the prospective, multicentre, non-randomized remedē ® System pilot study. Forty-seven patients with CSA were treated with the remedē ® System (Respicardia Inc., Minnetonka, MN, USA) for a minimum of 3 months. Sleep-disordered breathing parameters were evaluated by polysomnography (PSG) at 3, 6, and 12-month follow-up. Sleep symptoms and quality of life were also evaluated. Forty-one patients completed all follow-up PSGs and were included in the analysis. At 12 months, there was sustained improvement compared with baseline in the apnoea-hypopnoea index (49.9 ± 15.1 vs. 27.5 ± 18.3 events/h, P phrenic nerve stimulation is associated with sustained improvement in key sleep parameters, sleep symptoms, and quality of life over 12 months of follow-up. © 2016 The Authors. European Journal of Heart Failure © 2016 European Society of Cardiology.

Mild Concussion, but Not Moderate Traumatic Brain Injury, Is Associated with Long-Term Depression-Like Phenotype in Mice.

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Nikita M Bajwa

Full Text Available Mild traumatic brain injuries can lead to long-lasting cognitive and motor deficits, increasing the risk of future behavioral, neurological, and affective disorders. Our study focused on long-term behavioral deficits after repeated injury in which mice received either a single mild CHI (mCHI, a repeated mild CHI (rmCHI consisting of one impact to each hemisphere separated by 3 days, or a moderate controlled cortical impact injury (CCI. Shams received only anesthesia. Behavioral tests were administered at 1, 3, 5, 7, and 90 days post-injury (dpi. CCI animals showed significant motor and sensory deficits in the early (1-7 dpi and long-term (90 dpi stages of testing. Interestingly, sensory and subtle motor deficits in rmCHI animals were found at 90 dpi. Most importantly, depression-like behaviors and social passiveness were observed in rmCHI animals at 90 dpi. These data suggest that mild concussive injuries lead to motor and sensory deficits and affective disorders that are not observed after moderate TBI.

Action Observation and Motor Imagery: Innovative Cognitive Tools in the Rehabilitation of Parkinson’s Disease

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Giovanni Abbruzzese

2015-01-01

Full Text Available Parkinson’s disease (PD is characterized by a progressive impairment of motor skills with deterioration of autonomy in daily living activities. Physiotherapy is regarded as an adjuvant to pharmacological and neurosurgical treatment and may provide small and short-lasting clinical benefits in PD patients. However, the development of innovative rehabilitation approaches with greater long-term efficacy is a major unmet need. Motor imagery (MI and action observation (AO have been recently proposed as a promising rehabilitation tool. MI is the ability to imagine a movement without actual performance (or muscle activation. The same cortical-subcortical network active during motor execution is engaged in MI. The physiological basis of AO is represented by the activation of the “mirror neuron system.” Both MI and AO are involved in motor learning and can induce improvements of motor performance, possibly mediated by the development of plastic changes in the motor cortex. The review of available evidences indicated that MI ability and AO feasibility are substantially preserved in PD subjects. A few preliminary studies suggested the possibility of using MI and AO as parts of rehabilitation protocols for PD patients.

Retrospective attention in short-term memory has a lasting effect on long-term memory across age.

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Strunk, Jonathan; Morgan, Lauren; Reaves, Sarah; Verhaeghen, Paul; Duarte, Audrey

2018-04-13

Declines in both short- and long-term memory are typical of healthy aging. Recent findings suggest that retrodictive attentional cues ("retro-cues") that indicate the location of to-be-probed items in short-term memory (STM) have a lasting impact on long-term memory (LTM) performance in young adults. Whether older adults can also use retro-cues to facilitate both STM and LTM is unknown. Young and older adults performed a visual STM task in which spatially informative retro-cues or non-informative neutral-cues were presented during STM maintenance of real-world objects. We tested participants' memory at both STM and LTM delays for objects that were previously cued with retrodictive or neutral cues during STM order to measure the lasting impact of retrospective attention on LTM. Older adults showed reduced STM and LTM capacity compared to young adults. However, they showed similar magnitude retro-cue memory benefits as young adults at both STM and LTM delays. To the best of our knowledge, this is the first study to investigate whether retro-cues in STM facilitate the encoding of objects into LTM such that they are more likely to be subsequently retrieved by older adults. Our results support the idea that retrospective attention can be an effective means by which older adults can improve their short and long-term memory performance, even in the context of reduced memory capacity.

Electrical stimulation and motor recovery.

Science.gov (United States)

Young, Wise

2015-01-01

In recent years, several investigators have successfully regenerated axons in animal spinal cords without locomotor recovery. One explanation is that the animals were not trained to use the regenerated connections. Intensive locomotor training improves walking recovery after spinal cord injury (SCI) in people, and >90% of people with incomplete SCI recover walking with training. Although the optimal timing, duration, intensity, and type of locomotor training are still controversial, many investigators have reported beneficial effects of training on locomotor function. The mechanisms by which training improves recovery are not clear, but an attractive theory is available. In 1949, Donald Hebb proposed a famous rule that has been paraphrased as "neurons that fire together, wire together." This rule provided a theoretical basis for a widely accepted theory that homosynaptic and heterosynaptic activity facilitate synaptic formation and consolidation. In addition, the lumbar spinal cord has a locomotor center, called the central pattern generator (CPG), which can be activated nonspecifically with electrical stimulation or neurotransmitters to produce walking. The CPG is an obvious target to reconnect after SCI. Stimulating motor cortex, spinal cord, or peripheral nerves can modulate lumbar spinal cord excitability. Motor cortex stimulation causes long-term changes in spinal reflexes and synapses, increases sprouting of the corticospinal tract, and restores skilled forelimb function in rats. Long used to treat chronic pain, motor cortex stimuli modify lumbar spinal network excitability and improve lower extremity motor scores in humans. Similarly, epidural spinal cord stimulation has long been used to treat pain and spasticity. Subthreshold epidural stimulation reduces the threshold for locomotor activity. In 2011, Harkema et al. reported lumbosacral epidural stimulation restores motor control in chronic motor complete patients. Peripheral nerve or functional electrical

Fabrication of flower-like tin/carbon composite microspheres as long-lasting anode materials for lithium ion batteries

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Kang, Tae-Woo [Department of Chemical Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Lim, Hyung-Seok [Department of WCU Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Park, Seong-Jin [Department of Chemical Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Sun, Yang-Kook [Department of WCU Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Suh, Kyung-Do, E-mail: kdsuh@hanyang.ac.kr [Department of Chemical Engineering, College of Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of)

2017-01-01

In this work, we report the fabrication of the flower-like tin/carbon (Sn/C) composite microspheres using sulfonated semi-interpenetrating polystyrene (SPS) microspheres as a carbon precursor. The sulfonation degree of SPS has great effects on the resulting particle size, morphology, amount of introduced Sn, and the carbonization yield of the microspheres after heat treatment. The obtained Sn/C composite microspheres were characterized by scanning electron microscopy (SEM), focused-ion beam SEM, and X-ray diffraction. The flower-like Sn/C composite electrodes exhibited higher charge-discharge capacities than those of graphite as an anode material for a lithium ion battery. In addition, they show a long lasting cyclability, even through 400 cycles. - Highlights: • Tin nanocrystals are introduced in flower-like carbon spheres with many ripples. • Long lasting cyclability is exhibited at 1 C rate up to 400 cycles. • Tin content of composite spheres depends on chemical treatment of polymer microspheres.

Mechatronical Design Studies on Small Brushless Motors

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W. Amrhein

2003-01-01

Full Text Available Brushless DC- and AC-permanent-magnet motors controlled by powerful micro-controller electronics have opened up a significant share of the small motor market in the last years. Based on the mechanical low cost construction of single-phase motor the paper presents electronic drive concepts to improve the performance and for special applications also the lifetime of brushless motors. The tangential and radial forces acting on the rotor are controlled by special phase current curves to reduce the torque ripple and to avoid expendable machinery parts like ball or sliding bearings.

Statistically rigorous calculations do not support common input and long-term synchronization of motor-unit firings

Science.gov (United States)

Kline, Joshua C.

2014-01-01

Over the past four decades, various methods have been implemented to measure synchronization of motor-unit firings. In this work, we provide evidence that prior reports of the existence of universal common inputs to all motoneurons and the presence of long-term synchronization are misleading, because they did not use sufficiently rigorous statistical tests to detect synchronization. We developed a statistically based method (SigMax) for computing synchronization and tested it with data from 17,736 motor-unit pairs containing 1,035,225 firing instances from the first dorsal interosseous and vastus lateralis muscles—a data set one order of magnitude greater than that reported in previous studies. Only firing data, obtained from surface electromyographic signal decomposition with >95% accuracy, were used in the study. The data were not subjectively selected in any manner. Because of the size of our data set and the statistical rigor inherent to SigMax, we have confidence that the synchronization values that we calculated provide an improved estimate of physiologically driven synchronization. Compared with three other commonly used techniques, ours revealed three types of discrepancies that result from failing to use sufficient statistical tests necessary to detect synchronization. 1) On average, the z-score method falsely detected synchronization at 16 separate latencies in each motor-unit pair. 2) The cumulative sum method missed one out of every four synchronization identifications found by SigMax. 3) The common input assumption method identified synchronization from 100% of motor-unit pairs studied. SigMax revealed that only 50% of motor-unit pairs actually manifested synchronization. PMID:25210152

Strength and fine dexterity recovery profiles after a primary motor cortex insult and effect of a neuronal cell graft.

Science.gov (United States)

Vaysse, Laurence; Conchou, Fabrice; Demain, Boris; Davoust, Carole; Plas, Benjamin; Ruggieri, Cyrielle; Benkaddour, Mehdi; Simonetta-Moreau, Marion; Loubinoux, Isabelle

2015-08-01

The aim of this study was to set up (a) a large primary motor cortex (M1) lesion in rodent and (b) the conditions for evaluating a long-lasting motor deficit in order to propose a valid model to test neuronal replacement therapies aimed at improving motor deficit recovery. A mitochondrial toxin, malonate, was injected to induce extensive destruction of the forelimb M1 cortex. Three key motor functions that are usually evaluated following cerebral lesion in the clinic-strength, target reaching, and fine dexterity-were assessed in rats by 2 tests, a forelimb grip strength test and a skilled reaching task (staircase) for reaching and dexterity. The potential enhancement of postlesion recovery induced by a neuronal cell transplantation was then explored and confirmed by histological analyses. Both tests showed a severe functional impairment 2 days post lesion, however, reaching remained intact. Deficits in forelimb strength were long lasting (up to 3 months) but spontaneously recovered despite the extensive lesion size. This natural grip strength recovery could be enhanced by cell therapy. Histological analyses confirmed the presence of grafted cells 3 months postgraft and showed partial tissue reconstruction with some living neuronal cells in the graft. In contrast, fine dexterity never recovered in the staircase test even after grafting. These results suggest that cell replacement was only partially effective and that the forelimb M1 area may be a node of the sensorimotor network, where compensation from secondary pathways could account for strength recovery but recovery of forelimb fine dexterity requires extensive tissue reconstruction. (c) 2015 APA, all rights reserved).

Advanced AC Motor Control

Energy Technology Data Exchange (ETDEWEB)

Kazmierkowski, M.P. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warszawa (Poland)

1997-12-31

In this paper a review of control methods for high performance PWM inverter-fed induction motor drives is presented. Starting from the description of an induction motor by the help of the space vectors, three basic control strategic are discussed. As first, the most popular Field Oriented Control (FOC) is described. Secondly, the Direct Torque and Flux vector Control (DTFC) method, which - in contrast to FOC - depart from idea of coordinate transformation and analogy with DC motor, is briefly characterized. The last group is based on Feedback Linearization Control (FLC) and can be easy combined with sliding mode control. The simulation and experimental oscillograms that illustrate the performance of the discussed control strategies are shown. (orig.) 35 refs.

Chronic grouped social restriction triggers long-lasting immune system adaptations.

Science.gov (United States)

Tian, Rui; Hou, Gonglin; Song, Liuwei; Zhang, Jianming; Yuan, Ti-Fei

2017-05-16

Chronic stress triggers rigorous psychological and physiological changes, including immunological system adaptations. However, the effects of long-term social restriction on human immune system have not been investigated. The present study is to investigate the effect of chronic stress on immune changes in human blood, with the stress stimuli controlled.10 male volunteers were group isolated from the modern society in a 50-meter-square room for 150 days, with enriched nutrition and good living conditions provided. Serum examination of immune system markers demonstrated numerous changes in different aspects of the immune functions. The changes were observed as early as 30 days and could last for another 150 days after the termination of the restriction period (300 days' time point). The results strongly argued for the adaptation of immunological system under chronic social restriction stress in adult human, preceding a clear change in psychological conditions. The changes of these immune system factors could as well act as the serum biomarkers in clinical early-diagnosis of stress-related disorders.

What is happening to motor neuron disease in Nigeria? | Imam ...

African Journals Online (AJOL)

Background: Systematic studies of motor neuron disease were last reported from Ibadan, Nigeria, more than two decades ago. Since then, information about motor neuron disease has become limited making it necessary to review the current status of the disease. Methods: The clinical records of all cases of motor neuron ...

CT arteriography via the right inferior phrenic artery developed parasitic perfusion into the liver

International Nuclear Information System (INIS)

Inaba, Yoshitaka; Arai, Yasuaki; Sueyoshi, Satoshi; Yamagami, Takuji; Aramaki, Takeshi; Yamaura, Hidekazu; Matsueda, Kiyoshi; Sasaki, Fumio; Takeuchi, Yoshihito.

1998-01-01

The distribution of arterial blood flow via the right inferior phrenic artery (rt-IPA) developing parasitic perfusion into the liver was evaluated by CT arteriography (CTA) in 50 cases with hepatic tumors. In all cases, CTA via rt-IPA showed hyperperfusion area including hepatic tumors in the posterior segment and the caudate lobe of the liver, and adding the left hepatic lobe in cases with hepatic arterial occlusion. In 82% of 33 cases obtained both CTA via rt-IPA and CTA via hepatic artery, the hyperperfusion area on CTA via rt-IPA exactly corresponded to perfusion defect area on CTA via hepatic artery. CTA was much useful for understanding hemodynamics in cases with parasitic perfusion into the liver and it could make transcatheter arterial therapy more effective. (author)

CT arteriography via the right inferior phrenic artery developed parasitic perfusion into the liver

Energy Technology Data Exchange (ETDEWEB)

Inaba, Yoshitaka; Arai, Yasuaki; Sueyoshi, Satoshi; Yamagami, Takuji; Aramaki, Takeshi; Yamaura, Hidekazu; Matsueda, Kiyoshi; Sasaki, Fumio [Aichi Cancer Center, Nagoya (Japan); Takeuchi, Yoshihito

1998-02-01

The distribution of arterial blood flow via the right inferior phrenic artery (rt-IPA) developing parasitic perfusion into the liver was evaluated by CT arteriography (CTA) in 50 cases with hepatic tumors. In all cases, CTA via rt-IPA showed hyperperfusion area including hepatic tumors in the posterior segment and the caudate lobe of the liver, and adding the left hepatic lobe in cases with hepatic arterial occlusion. In 82% of 33 cases obtained both CTA via rt-IPA and CTA via hepatic artery, the hyperperfusion area on CTA via rt-IPA exactly corresponded to perfusion defect area on CTA via hepatic artery. CTA was much useful for understanding hemodynamics in cases with parasitic perfusion into the liver and it could make transcatheter arterial therapy more effective. (author)

The optimal timing of stimulation to induce long-lasting positive effects on episodic memory in physiological aging.

Science.gov (United States)

Manenti, Rosa; Sandrini, Marco; Brambilla, Michela; Cotelli, Maria

2016-09-15

Episodic memory displays the largest degree of age-related decline. A noninvasive brain stimulation technique that can be used to modulate memory in physiological aging is transcranial Direct Current Stimulation (tDCS). However, an aspect that has not been adequately investigated in previous studies is the optimal timing of stimulation to induce long-lasting positive effects on episodic memory function. Our previous studies showed episodic memory enhancement in older adults when anodal tDCS was applied over the left lateral prefrontal cortex during encoding or after memory consolidation with or without a contextual reminder. Here we directly compared the two studies to explore which of the tDCS protocols would induce longer-lasting positive effects on episodic memory function in older adults. In addition, we aimed to determine whether subjective memory complaints would be related to the changes in memory performance (forgetting) induced by tDCS, a relevant issue in aging research since individuals with subjective memory complaints seem to be at higher risk of later memory decline. The results showed that anodal tDCS applied after consolidation with a contextual reminder induced longer-lasting positive effects on episodic memory, conceivably through reconsolidation, than anodal tDCS during encoding. Furthermore, we reported, providing new data, a moderate negative correlation between subjective memory complaints and forgetting when anodal tDCS was applied after consolidation with a contextual reminder. This study sheds light on the best-suited timing of stimulation to induce long-lasting positive effects on memory function and might help the clinicians to select the most effective tDCS protocol to prevent memory decline. Copyright © 2016 Elsevier B.V. All rights reserved.

Severe and long-lasting diarrhea not recognized as adverse effect of metformin : A description of three elderly patients

NARCIS (Netherlands)

Lefeber, G.; Jansen, P.; Van Puijenbroek, E.

Background.- As a result of the United Kingdom Prospective Diabetes Study (UKPDS), metformin became the first choice drug for patients with diabetes. In 2009 three patients were admitted to our geriatric department for analysis of disabling long-lasting diarrhea. Metformin as causative agent was

NOVAE WITH LONG-LASTING SUPERSOFT EMISSION THAT DRIVE A HIGH ACCRETION RATE

International Nuclear Information System (INIS)

Schaefer, Bradley E.; Collazzi, Andrew C.

2010-01-01

We identify a new class of novae characterized by the post-eruption quiescent light curve being more than roughly a factor of 10 brighter than the pre-eruption light curve. Eight novae (V723 Cas, V1500 Cyg, V1974 Cyg, GQ Mus, CP Pup, T Pyx, V4633 Sgr, and RW UMi) are separated out as being significantly distinct from other novae. This group shares a suite of uncommon properties, characterized by the post-eruption magnitude being much brighter than before eruption, short orbital periods, long-lasting supersoft emission following the eruption, a highly magnetized white dwarf (WD), and secular declines during the post-eruption quiescence. We present a basic physical picture which shows why all five uncommon properties are causally connected. In general, novae show supersoft emission due to hydrogen burning on the WD in the final portion of the eruption, and this hydrogen burning will be long-lasting if new hydrogen is poured onto the surface at a sufficient rate. Most novae do not have adequate accretion for continuous hydrogen burning, but some can achieve this if the companion star is nearby (with short orbital period) and a magnetic field channels the matter onto a small area on the WD so as to produce a locally high accretion rate. The resultant supersoft flux irradiates the companion star and drives a higher accretion rate (with a brighter post-eruption phase), which serves to keep the hydrogen burning and the supersoft flux going. The feedback loop cannot be perfectly self-sustaining, so the supersoft flux will decline over time, forcing a decline in the accretion rate and the system brightness. We name this new group after the prototype, V1500 Cyg. V1500 Cyg stars are definitely not progenitors of Type Ia supernovae. The V1500 Cyg stars have similar physical mechanisms and appearances as predicted for nova by the hibernation model, but with this group accounting for only 14% of novae.

Risk Factors of Developing Long-Lasting Breast Pain After Breast Cancer Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Lundstedt, Dan, E-mail: dan.lundstedt@vgregion.se [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden); Gustafsson, Magnus [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Steineck, Gunnar [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Division of Clinical Cancer Epidemiology, Department of Oncology-Pathology, the Karolinska Institute, Stockholm (Sweden); Malmstroem, Per [Skane Department of Oncology, Skane University Hospital, Lund (Sweden); Alsadius, David [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden); Sundberg, Agnetha [Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Wilderaeng, Ulrica [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Holmberg, Erik [Oncologic Centre, Sahlgrenska University Hospital, Gothenburg (Sweden); Johansson, Karl-Axel [Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Karlsson, Per [Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden)

2012-05-01

Purpose: Postoperative radiotherapy decreases breast cancer mortality. However, studies have revealed a long-lasting breast pain among some women after radiotherapy. The purpose of this study was to identify risk factors that contribute to breast pain after breast cancer radiotherapy. Methods and Materials: We identified 1,027 recurrence-free women in two cohorts of Swedish women treated for breast cancer. The women had breast-conserving surgery and postoperative radiotherapy, the breast was treated to 48 Gy in 2.4-Gy fractions or to 50 Gy in 2.0-Gy fractions. Young women received a boost of up to 16 Gy. Women with more than three lymph node metastases had locoregional radiotherapy. Systemic treatments were given according to health-care guidelines. Three to 17 years after radiotherapy, we collected data using a study-specific questionnaire. We investigated the relation between breast pain and potential risk modifiers: age at treatment, time since treatment, chemotherapy, photon energy, fractionation size, boost, loco-regional radiotherapy, axillary surgery, overweight, and smoking. Results: Eight hundred seventy-seven women (85%) returned the questionnaires. Among women up to 39 years of age at treatment, 23.1% had breast pain, compared with 8.7% among women older than 60 years (RR 2.66; 95% CI 1.33-5.36). Higher age at treatment (RR 0.96; 95% CI 0.94-0.98, annual decrease) and longer time since treatment (RR 0.93; 95% CI 0.88-0.98, annual decrease) were related to a lower occurrence of breast pain. Chemotherapy increased the occurrence of breast pain (RR 1.72; 95% CI 1.19-2.47). In the multivariable model only age and time since treatment were statistically significantly related to the occurrence of breast pain. We found no statistically significant relation between breast pain and the other potential risk modifiers. Conclusions: Younger women having undergone breast-conserving surgery with postoperative radiotherapy report a higher occurrence of long-lasting

Phrenic nerve paralysis during cryoballoon ablation for atrial fibrillation: a comparison between the first- and second-generation balloon.

Science.gov (United States)

Casado-Arroyo, Ruben; Chierchia, Gian-Battista; Conte, Giulio; Levinstein, Moisés; Sieira, Juan; Rodriguez-Mañero, Moises; di Giovanni, Giacomo; Baltogiannis, Yannis; Wauters, Kristel; de Asmundis, Carlo; Sarkozy, Andrea; Brugada, Pedro

2013-09-01

Phrenic nerve palsy (PNP) is the most frequently observed complication during cryoballoon ablation (CB; Arctic Front, Medtronic, MN) occurring in roughly 7%-9% of the cases. The new second-generation cryoballoon ablation Arctic Front Advance (CB-A) (Arctic Front) has recently been launched in the market. To evaluate the incidence of right PNP with the new CB-A in comparison with the first-generation balloon in a series of consecutive patients that underwent pulmonary vein isolation with this modality. The study was designed as an observational study with a prospective follow-up. In total, 121 consecutive patients were included: 80 patients with the CB (group 1) and 41 with the CB-A (group 2). Mean procedural times, fluoroscopic times, and time to pulmonary vein isolation documented by real-time recordings were significantly lower in group 2 (P ≤ .05). The occurrence of PNP was significantly higher in group 2 (6.25% [5 of 80] in group 1 vs 19.5% [8 of 41] in group 2; P = .033). At 7 months, PNP persisted in 1 (2.5%) patient in the CB-A group. Right PNP seems to occur in a significantly larger number of patients with the second-generation CB-A. However, this complication is reversible in nearly all cases on short-term follow-up. More refined phrenic nerve monitoring during right-sided pulmonary vein ablation and less vigorous wedging maneuvers in the pulmonary vein ostia might significantly reduce the occurrence of this complication. © 2013 Heart Rhythm Society. All rights reserved.

Energetic ion excited long-lasting ``sword'' modes in tokamak plasmas with low magnetic shear

Science.gov (United States)

Wang, Xiaogang; Zhang, Ruibin; Deng, Wei; Liu, Yi

2013-10-01

An m/ n = 1 mode driven by trapped fast ions with a sword-shape envelope of long-lasting (for hundreds of milliseconds) magnetic perturbation signals, other than conventional fishbones, is studied in this paper. The mode is usually observed in low shear plasmas. Frequency and growth rate of the mode and its harmonics are calculated and in good agreements with observations. The radial mode structure is also obtained and compared with that of fishbones. It is found that due to fast ion driven the mode differs from magnetohydrodynamic long lived modes (LLMs) observed in MAST and NSTX. On the other hand, due to the feature of weak magnetic shear, the mode is also significantly different from fishbones. The nonlinear evolution of the mode and its comparison with fishbones are further investigated to analyze the effect of the mode on energetic particle transport and confinement.

Culminating anti-malaria efforts at long lasting insecticidal net?

Directory of Open Access Journals (Sweden)

Sunil Dhiman

2014-11-01

Full Text Available Summary: Background: Long-lasting insecticidal nets (LLINs are a primary method in malaria control efforts. However, a decline in the biological efficacy and physical integrity over a period of comparatively lesser time than claimed, waning of naturally acquired immunity among regular users and misuse of LLINs are serious concerns. Search and selection of literature: The literature for the current review was searched in PubMed, SCOPUS Database and Google using combined search strings of related key-words. Literature with sufficient data and information on the current subject was selected to reach a valid conclusion. Findings: The World Health Organization (WHO has emphasized that LLINs should be considered a public good for people inhabiting malaria endemic settings. LLINs exhibited a cumulative effect on the vector density and may force anthropophilic mosquito vectors to find alternative animal hosts for blood meal. However, the physical integrity and biological activity of LLINs declines faster than the anticipated time due to different operational conditions and the spread of insecticide resistance. LLINs have been successful in reducing malaria incidences by either reducing or not allowing human exposure to the vector mosquitoes, but at the same time, LLINs debilitate the natural protective immunity against malaria parasite. Misuse of LLINs for deviant purposes is common and is a serious environmental concern, as people believe that traditional methods of prevention against malaria that have enabled them to survive through a long time are effective and sufficient. Moreover, people are often ill-informed regarding the toxic effects of LLINs. Conclusions: Specific criteria for determining the serviceable life and guidelines on the safe washing and disposal of LLINs need to be developed, kept well-informed and closely monitored. Malaria case management, environment management and community awareness to reduce the misuse of LLINs are crucial

Protein Synthesis Inhibition in the Peri-Infarct Cortex Slows Motor Recovery in Rats.

Science.gov (United States)

Schubring-Giese, Maximilian; Leemburg, Susan; Luft, Andreas Rüdiger; Hosp, Jonas Aurel

2016-01-01

Neuroplasticity and reorganization of brain motor networks are thought to enable recovery of motor function after ischemic stroke. Especially in the cortex surrounding the ischemic scar (i.e., peri-infarct cortex), evidence for lasting reorganization has been found at the level of neurons and networks. This reorganization depends on expression of specific genes and subsequent protein synthesis. To test the functional relevance of the peri-infarct cortex for recovery we assessed the effect of protein synthesis inhibition within this region after experimental stroke. Long-Evans rats were trained to perform a skilled-reaching task (SRT) until they reached plateau performance. A photothrombotic stroke was induced in the forelimb representation of the primary motor cortex (M1) contralateral to the trained paw. The SRT was re-trained after stroke while the protein synthesis inhibitor anisomycin (ANI) or saline were injected into the peri-infarct cortex through implanted cannulas. ANI injections reduced protein synthesis within the peri-infarct cortex by 69% and significantly impaired recovery of reaching performance through re-training. Improvement of motor performance within a single training session remained intact, while improvement between training sessions was impaired. ANI injections did not affect infarct size. Thus, protein synthesis inhibition within the peri-infarct cortex impairs recovery of motor deficits after ischemic stroke by interfering with consolidation of motor memory between training sessions but not short-term improvements within one session.

A randomised, controlled, double-blind trial of ultrasound-guided phrenic nerve block to prevent shoulder pain after thoracic surgery

DEFF Research Database (Denmark)

Blichfeldt-Eckhardt, M R; Laursen, C B; Berg, H

2016-01-01

to receive an ultrasound-guided supraclavicular phrenic nerve block with 10 ml ropivacaine or 10 ml saline (placebo) immediately following surgery. A nerve catheter was subsequently inserted and treatment continued for 3 days. The study drug was pharmaceutically pre-packed in sequentially numbered identical...... vials assuring that all participants, healthcare providers and data collectors were blinded. The primary outcome was the incidence of unilateral shoulder pain within the first 6 h after surgery. Pain was evaluated using a numeric rating scale. Nine of 38 patients in the ropivacaine group and 26 of 38...

Basal Ganglia Activity Mirrors a Benefit of Action and Reward on Long-Lasting Event Memory.

Science.gov (United States)

Koster, Raphael; Guitart-Masip, Marc; Dolan, Raymond J; Düzel, Emrah

2015-12-01

The expectation of reward is known to enhance a consolidation of long-term memory for events. We tested whether this effect is driven by positive valence or action requirements tied to expected reward. Using a functional magnetic resonance imaging (fMRI) paradigm in young adults, novel images predicted gain or loss outcomes, which in turn were either obtained or avoided by action or inaction. After 24 h, memory for these images reflected a benefit of action as well as a congruence of action requirements and valence, namely, action for reward and inaction for avoidance. fMRI responses in the hippocampus, a region known to be critical for long-term memory function, reflected the anticipation of inaction. In contrast, activity in the putamen mirrored the congruence of action requirement and valence, whereas other basal ganglia regions mirrored overall action benefits on long-lasting memory. The findings indicate a novel type of functional division between the hippocampus and the basal ganglia in the motivational regulation of long-term memory consolidation, which favors remembering events that are worth acting for. © The Author 2015. Published by Oxford University Press.

Effects of acute sleep deprivation on motor and reversal learning in mice.

Science.gov (United States)

Varga, Andrew W; Kang, Mihwa; Ramesh, Priyanka V; Klann, Eric

2014-10-01

Sleep supports the formation of a variety of declarative and non-declarative memories, and sleep deprivation often impairs these types of memories. In human subjects, natural sleep either during a nap or overnight leads to long-lasting improvements in visuomotor and fine motor tasks, but rodent models recapitulating these findings have been scarce. Here we present evidence that 5h of acute sleep deprivation impairs mouse skilled reach learning compared to a matched period of ad libitum sleep. In sleeping mice, the duration of total sleep time during the 5h of sleep opportunity or during the first bout of sleep did not correlate with ultimate gain in motor performance. In addition, we observed that reversal learning during the skilled reaching task was also affected by sleep deprivation. Consistent with this observation, 5h of sleep deprivation also impaired reversal learning in the water-based Y-maze. In conclusion, acute sleep deprivation negatively impacts subsequent motor and reversal learning and memory. Copyright © 2014 Elsevier Inc. All rights reserved.

Long-Term Resolution of Severe Ankle Contractures Using Botulinum Toxin, Serial Casting, Splinting, and Motor Retraining.

Science.gov (United States)

Leung, Joan; Stroud, Katarina

2018-01-01

Purpose: Serial casting for ankle contractures is traditionally performed in prone, a position that patients may not easily tolerate. Also, although serial casting is effective in correcting contracture, its effect dissipates quickly. This case report describes a procedure for performing casting for ankle contractures in a supine or sitting position. It also describes a process that enables the effect of serial casting to be maintained long term. Client Description: The client was an adult who had suffered traumatic brain injury and severe bilateral ankle contractures. Intervention: He received botulinum toxin and serial casting for his bilateral ankle contractures, one ankle at 8 months and the other at 13 months after the injury. He then underwent a programme of splinting and motor training. Measures and Outcome: The client gained more than 40° dorsiflexion for both ankles after receiving botulinum toxin injections and serial casting. The improvement in ankle range enabled him to progress to walking practice. Ankle splinting was gradually reduced. On discharge at 25 months post-injury, the ankle joint range was maintained. Implications: The use of botulinum toxin and serial casting, followed by an intensive programme of splinting and motor training, may be an option to consider for effective long-term resolution of severe contractures after acquired brain injury.

Effects of transcranial direct current stimulation on motor learning in healthy individuals: a systematic review

Directory of Open Access Journals (Sweden)

Águida Foerster

Full Text Available Introduction Transcranial direct current stimulation (tDCS has been used to modify cortical excitability and promote motor learning. Objective To systematically review published data to investigate the effects of transcranial direct current stimulation on motor learning in healthy individuals. Methods Randomized or quasi-randomized studies that evaluated the tDCS effects on motor learning were included and the risk of bias was examined by Cochrane Collaboration’s tool. The following electronic databases were used: PubMed, Scopus, Web of Science, LILACS, CINAHL with no language restriction. Results It was found 160 studies; after reading the title and abstract, 17 of those were selected, but just 4 were included. All studies involved healthy, right-handed adults. All studies assessed motor learning by the Jebsen Taylor Test or by the Serial Finger Tapping Task (SFTT. Almost all studies were randomized and all were blinding for participants. Some studies presented differences at SFTT protocol. Conclusion The result is insufficient to draw conclusions if tDCS influences the motor learning. Furthermore, there was significant heterogeneity of the stimulation parameters used. Further researches are needed to investigate the parameters that are more important for motor learning improvement and measure whether the effects are long-lasting or limited in time.

Restraint training for awake functional brain scanning of rodents can cause long-lasting changes in pain and stress responses.

Science.gov (United States)

Low, Lucie A; Bauer, Lucy C; Pitcher, Mark H; Bushnell, M Catherine

2016-08-01

With the increased interest in longitudinal brain imaging of awake rodents, it is important to understand both the short-term and long-term effects of restraint on sensory and emotional processing in the brain. To understand the effects of repeated restraint on pain behaviors and stress responses, we modeled a restraint protocol similar to those used to habituate rodents for magnetic resonance imaging scanning, and studied sensory sensitivity and stress hormone responses over 5 days. To uncover lasting effects of training, we also looked at responses to the formalin pain test 2 weeks later. We found that while restraint causes acute increases in the stress hormone corticosterone, it can also cause lasting reductions in nociceptive behavior in the formalin test, coupled with heightened corticosterone levels and increased activation of the "nociceptive" central nucleus of the amygdala, as seen by Fos protein expression. These results suggest that short-term repeated restraint, similar to that used to habituate rats for awake functional brain scanning, could potentially cause long-lasting changes in physiological and brain responses to pain stimuli that are stress-related, and therefore could potentially confound the functional activation patterns seen in awake rodents in response to pain stimuli.

Repeated Transient Jets from a Warped Disk in the Symbiotic Prototype Z And: A Link to the Long-lasting Active Phase

Science.gov (United States)

Skopal, Augustin; Tarasova, Taya. N.; Wolf, Marek; Dubovský, Pavol A.; Kudzej, Igor

2018-05-01

Active phases of some symbiotic binaries survive for a long time, from years to decades. The accretion process onto a white dwarf (WD) sustaining long-lasting activity, and sometimes leading to collimated ejection, is not well understood. We present the repeated emergence of highly collimated outflows (jets) from the symbiotic prototype Z And during its 2008 and 2009–10 outbursts and suggest their link to the current long-lasting (from 2000) active phase. We monitored Z And with high-resolution spectroscopy, multicolor UBVR C—and high time resolution—photometry. The well-pronounced bipolar jets were ejected again during the 2009–10 outburst together with the simultaneous emergence of the rapid photometric variability (Δm ≈ 0.06 mag) on the timescale of hours, showing similar properties as those during the 2006 outburst. These phenomena and the measured disk–jets connection could be caused by the radiation-induced warping of the inner disk due to a significant increase of the burning WD luminosity. Ejection of transient jets by Z And around outburst maxima signals a transient accretion at rates above the upper limit of the stable hydrogen burning on the WD surface, and thus proves the nature of Z And-type outbursts. The enhanced accretion through the disk warping, supplemented by the accretion from the giant’s wind, can keep a high luminosity of the WD for a long time, until depletion of the disk. In this way, the jets provide a link to long-lasting active phases of Z And.

Exposure to severe stressors causes long-lasting dysregulation of resting and stress-induced activation of the hypothalamic-pituitary-adrenal axis.

Science.gov (United States)

Belda, Xavier; Rotllant, David; Fuentes, Silvia; Delgado, Raúl; Nadal, Roser; Armario, Antonio

2008-12-01

Exposure to some predominantly emotional (electric shock) and systemic (interleukin-1beta) stressors has been found to induce long-term sensitization of the hypothalamic-pituitary-adrenal (HPA) responsiveness to further superimposed stressors. Since exposure to immobilization on wooden boards (IMO) is a severe stressor and may have interest regarding putative animal models of post-traumatic stress disorders (PTSD), we have characterized long-lasting effects of a single exposure to IMO and other stressors on the HPA response to the same (homotypic) and to novel (heterotypic) stressors and the putative mechanisms involved. A single exposure to IMO caused a long-lasting reduction of peripheral and central responses of the HPA axis, likely to be mediated by some brain areas, such as the lateral septum and the medial amygdala. This desensitization is not explained by changes in negative glucocorticoid feedback, and, surprisingly, it is positively related to the intensity of the stressors. In contrast, the HPA response to heterotypic stressors (novel environments) was enhanced, with maximal sensitization on the day after IMO. Sensitization progressively vanished over the course of 1-2 weeks and was not modulated by IMO-induced corticosterone release. Moreover, it could not be explained by changes in the sensitivity of the HPA axis to fast or intermediate/delayed negative feedback, as evaluated 1 week after exposure to IMO, using shock as the heterotypic stressor. Long-lasting stress-induced behavioral changes reminiscent of enhanced anxiety and HPA sensitization are likely to be parallel but partially independent phenomena, the former being apparently not related to the intensity of stressors.

Acute exercise improves motor memory

DEFF Research Database (Denmark)

Skriver, Kasper Christen; Roig, Marc; Lundbye-Jensen, Jesper

2014-01-01

We have recently shown that a single bout of acute cardiovascular exercise improves motor skill learning through an optimization of long-term motor memory. Here we expand this previous finding, to explore potential exercise-related biomarkers and their association with measures of motor memory...... practice whereas lactate correlated with better retention 1 hour as well as 24 hours and 7 days after practice. Thus, improvements in motor skill acquisition and retention induced by acute cardiovascular exercise are associated with increased concentrations of biomarkers involved in memory and learning...... processes. More mechanistic studies are required to elucidate the specific role of each biomarker in the formation of motor memory....

Long-lasting effects of performance-contingent unconscious and conscious reward incentives during cued task-switching.

Science.gov (United States)

Capa, Rémi L; Bouquet, Cédric A; Dreher, Jean-Claude; Dufour, André

2013-01-01

Motivation is often thought to interact consciously with executive control, although recent studies have indicated that motivation can also be unconscious. To date, however, the effects of unconscious motivation on high-order executive control functions have not been explored. Only a few studies using subliminal stimuli (i.e., those not related to motivation, such as an arrow to prime a response) have reported short-lived effects on high-order executive control functions. Here, building on research on unconscious motivation, in which a behavior of perseverance is induced to attain a goal, we hypothesized that subliminal motivation can have long-lasting effects on executive control processes. We investigated the impact of unconscious/conscious monetary reward incentives on evoked potentials and neural activity dynamics during cued task-switching performance. Participants performed long runs of task-switching. At the beginning of each run, a reward (50 cents or 1 cent) was displayed, either subliminally or supraliminally. Participants earned the reward contingent upon their correct responses to each trial of the run. A higher percentage of runs was achieved with higher (conscious and unconscious) than lower rewards, indicating that unconscious high rewards have long-lasting behavioral effects. Event-related potential (ERP) results indicated that unconscious and conscious rewards influenced preparatory effort in task preparation, as suggested by a greater fronto-central contingent negative variation (CNV) starting at cue-onset. However, a greater parietal P3 associated with better reaction times (RTs) was observed only under conditions of conscious high reward, suggesting a larger amount of working memory invested during task performance. Together, these results indicate that unconscious and conscious motivations are similar at early stages of task-switching preparation but differ during task performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Control of permanent magnet synchronous motors

CERN Document Server

Vaez-Zadeh, Sadegh

2018-01-01

This is the first comprehensive, coherent, and up-to-date book devoted solely to the control of permanent magnet synchronous (PMS) motors, as the fastest growing AC motor. It covers a deep and detailed presentation of major PMS motor modeling and control methods. The readers can find rich materials on the fundamentals of PMS motor control in addition to new motor control methods, which have mainly been developed in the last two decades, including recent advancements in the field in a systematic manner. These include extensive modeling of PMS motors and a full range of vector control and direct torque control schemes, in addition to predictive control, deadbeat control, and combined control methods. All major sensorless control and parameter estimation methods are also studied. The book covers about 10 machine models in various reference frames and 70 control and estimation schemes with sufficient analytical and implementation details including about 200 original figures. A great emphasis is placed on energy-s...

Long lasting attentional-context dependent visuomotor memory

OpenAIRE

Im, Hee Yeon; Bédard, Patrick; Song, Joo-Hyun

2016-01-01

Using a dual-task paradigm, we recently reported that visuomotor adaptation acquired under distraction of a secondary attention-demanding discrimination task could be remembered only when a similar distraction was present. In contrast, when tested without the distracting task, performance reverted to untrained levels (Song & Bédard, 2015). Here, we demonstrated that this newfound paradoxical benefits of consistent dual-task context lasts over one day, such that visuomotor memory retrieval is ...

Mobility of adult Tribolium castaneum (Coleoptera: Tenebrionidae) and Rhyzopertha dominica (Coleoptera: Bostrichidae) after exposure to long-lasting insecticide netting

Science.gov (United States)

Stored products represent an enormous economic output, but insects regularly immigrate into stored products from the surrounding landscape throughout the post-harvest supply chain. Long-lasting insecticide netting (LLIN), which usually contains an impregnated pyrethroid, has been used as part of a s...

A single bout of exercise improves motor memory

DEFF Research Database (Denmark)

Roig, Marc; Skriver, Kasper Christen; Lundbye-Jensen, Jesper

2012-01-01

Regular physical activity has a positive impact on cognition and brain function. Here we investigated if a single bout of exercise can improve motor memory and motor skill learning. We also explored if the timing of the exercise bout in relation to the timing of practice has any impact on the acq...... exercise on long-term motor memory....... that exercised before practice, the subjects that exercised after practice showed a better retention of the motor skill 7 days after practice. These findings indicate that one bout of intense exercise performed immediately before or after practicing a motor task is sufficient to improve the long-term retention......Regular physical activity has a positive impact on cognition and brain function. Here we investigated if a single bout of exercise can improve motor memory and motor skill learning. We also explored if the timing of the exercise bout in relation to the timing of practice has any impact...

Motor cortex stimulation does not lead to functional recovery after experimental cortical injury in rats.

Science.gov (United States)

Schönfeld, Lisa-Maria; Jahanshahi, Ali; Lemmens, Evi; Bauwens, Matthias; Hescham, Sarah-Anna; Schipper, Sandra; Lagiere, Melanie; Hendrix, Sven; Temel, Yasin

2017-01-01

Motor impairments are among the major complications that develop after cortical damage caused by either stroke or traumatic brain injury. Motor cortex stimulation (MCS) can improve motor functions in animal models of stroke by inducing neuroplasticity. In the current study, the therapeutic effect of chronic MCS was assessed in a rat model of severe cortical damage. A controlled cortical impact (CCI) was applied to the forelimb area of the motor cortex followed by implantation of a flat electrode covering the lesioned area. Forelimb function was assessed using the Montoya staircase test and the cylinder test before and after a period of chronic MCS. Furthermore, the effect of MCS on tissue metabolism and lesion size was measured using [18F]-fluorodesoxyglucose (FDG) μPET scanning. CCI caused a considerable lesion at the level of the motor cortex and dorsal striatum together with a long-lasting behavioral phenotype of forelimb impairment. However, MCS applied to the CCI lesion did not lead to any improvement in limb functioning when compared to non-stimulated control rats. Also, MCS neither changed lesion size nor distribution of FDG. The use of MCS as a standalone treatment did not improve motor impairments in a rat model of severe cortical damage using our specific treatment modalities.

Vascular impairment as a pathological mechanism underlying long-lasting cognitive dysfunction after pediatric traumatic brain injury.

Science.gov (United States)

Ichkova, Aleksandra; Rodriguez-Grande, Beatriz; Bar, Claire; Villega, Frederic; Konsman, Jan Pieter; Badaut, Jerome

2017-12-01

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Indeed, the acute mechanical injury often evolves to a chronic brain disorder with long-term cognitive, emotional and social dysfunction even in the case of mild TBI. Contrary to the commonly held idea that children show better recovery from injuries than adults, pediatric TBI patients actually have worse outcome than adults for the same injury severity. Acute trauma to the young brain likely interferes with the fine-tuned developmental processes and may give rise to long-lasting consequences on brain's function. This review will focus on cerebrovascular dysfunction as an important early event that may lead to long-term phenotypic changes in the brain after pediatric TBI. These, in turn may be associated with accelerated brain aging and cognitive dysfunction. Finally, since no effective treatments are currently available, understanding the unique pathophysiological mechanisms of pediatric TBI is crucial for the development of new therapeutic options. Copyright © 2017 Elsevier Ltd. All rights reserved.

A long-lasting wireless stimulator for small mammals

Directory of Open Access Journals (Sweden)

Ian D Hentall

2013-10-01

Full Text Available The chronic effects of electrical stimulation in unrestrained awake rodents are best studied with a wireless neural stimulator that can operate unsupervised for several weeks or more. A robust, inexpensive, easily built, cranially implantable stimulator was developed to explore the restorative effects of brainstem stimulation after neurotrauma. Its connectorless electrodes directly protrude from a cuboid epoxy capsule containing all circuitry and power sources. This physical arrangement prevents fluid leaks or wire breakage and also simplifies and speeds implantation. Constant-current pulses of high compliance (34 volts are delivered from a step-up voltage regulator under microprocessor control. A slowly pulsed magnetic field controls activation state and stimulation parameters. Program status is signaled to a remote reader by interval-modulated infrared pulses. Capsule size is limited by the two batteries. Silver oxide batteries rated at 8 milliamp-hours were used routinely in 8 mm wide, 15 mm long and 4 mm high capsules. Devices of smaller contact area (5 by 12 mm but taller (6 mm were created for mice. Microstimulation of the rat’s raphe nuclei with intermittent 5-minute (50% duty cycle trains of 30 µA, 1 ms pulses at 8 or 24 Hz frequency during 12 daylight hours lasted 21.1 days ±0.8 (mean ± standard error, Kaplan-Meir censored estimate, n=128. Extended lifetimes (>6 weeks, no failures, n=16 were achieved with larger batteries (44 milliamp-hours in longer (18 mm, taller (6 mm capsules. The circuit and electrode design are versatile; simple modifications allowed durable constant-voltage stimulation of the rat’s sciatic nerve through a cylindrical cathode from a subcutaneous pelvic capsule. Devices with these general features can address in small mammals many of the biological and technical questions arising neurosurgically with prolonged peripheral or deep brain stimulation.

Effect of the long-term care prevention project on the motor functions and daily life activities of the elderly.

Science.gov (United States)

Wada, Yoshihiro; Sakuraba, Keisyoku; Kubota, Atsushi

2015-01-01

[Purpose] The purpose of this study was to verify the effects of the long-term care prevention project and develop an effective program. [Subjects] A total of 81 elderly people (age, 79 ± 5.1 years; height, 149.2 ± 9.2 cm; weight, 54.2 ± 11.4 kg). [Methods] Grip, knee extension muscular strength, 10 m walking speed, and Timed Up and Go time were measured for evaluation of motor functions, and the "Locomo 25", a 25-question risk assessment questionnaire, was used as the judgment criterion for evaluation of daily life activities, with measurements being taken at the beginning of the project and after three months. [Results] In the motor functions evaluation, significant differences were observed in 10 m walking speed, Timed Up and Go time, and knee extension strength. In the daily life activities evaluation, scores for pain, rising movement, standing movement, indoor walking, outdoor walking, and fear of falling were significantly reduced. In addition, a significant correlation was also observed between motor functions and daily life activities. [Conclusion] The result of this study indicated that the long-term care prevention project is effective in maintaining or improving muscular strength and mitigating pain in the elderly and that it is an effective program for maintaining daily life activities. We were also able to show that it would be effective to develop programs with a low exercise intensity that can be performed on a continuing by the elderly.

[Phrenic nerve stimulation protects against mechanical ventilation-induced diaphragmatic dysfunction through myogenic regulatory factors].

Science.gov (United States)

An, G H; Chen, M; Zhan, W F; Hu, B; Zhang, H X

2018-02-12

Objective: To explore the protective effect of electrical stimulation of phrenic nerve on diaphragmatic function during mechanical ventilation. Methods: Forty healthy adult SD rats were randomly divided into 5 groups: blank control group (BC), spontaneous breathing group (SB), electrical stimulation group (ES), mechanical ventilation group (MV), and electrical stimulation and mechanical ventilation group (MS). The rats in each group were treated for 18 h except for the BC group. After treatment, the diaphragm muscle tissue was obtained and the diaphragm contractility including peak-to-peak value(Vpp) and maximum rate of contraction(+ dT/dt max) were measured. Expression of MyoD and myogenin were detected. Results: Except for the ES and the MS groups, there was a significant difference for peak-to-peak value (Vpp) between each 2 groups ( P mechanical ventilation induced diaphragmatic function damage, and therefore plays a protective effect on the diaphragm.

Effect of intermittent glutamine supplementation on skeletal muscle is not long-lasting in very old rats.

Science.gov (United States)

Meynial-Denis, D; Beaufrère, A-M; Mignon, M; Patureau Mirand, P

2013-01-01

Muscle is the major site for glutamine synthesis via glutamine synthetase (GS). This enzyme is increased 1.5-2 fold in 25-27-mo rats and may be a consequence of aging-induced stress. This stimulation is similar to the induction observed following a catabolic state such as glucocorticoid treatment (6 to 24 months). Although oral glutamine supply regulates the plasma glutamine level, nothing is known if this supplementation is interrupted before the experiment. Adult (8-mo) and very old (27-mo) female rats were exposed to intermittent glutamine supplementation for 50 % of their age lifetime. Treated rats received glutamine added to their drinking water and control rats water alone but the effect of glutamine supplementation was only studied 15 days after the last supplementation. Glutamine pretreatment discontinued 15 days before the experiment increased plasma glutamine to ~ 0.6 mM, a normal value in very old rats. However, it failed to decrease the up-regulated GS activity in skeletal muscle from very old rats. Our results suggest that long-term treatment with glutamine started before advanced age but discontinued 15 days before rat sacrifice is effective in increasing plasma glutamine to recover basal adult value and in maintaining plasma glutamine in very old rats, but has no long-lasting effect on the GS activity of skeletal muscle with advanced age.

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

International Nuclear Information System (INIS)

Alba, Martha P.; Suarez, Carlos F.; Varela, Yahson; Patarroyo, Manuel A.; Bermudez, Adriana; Patarroyo, Manuel E.

2016-01-01

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged 60 days later with a lethal Aotus monkey-adapted P. falciparum strain was found to be associated with preferential high binding capacity to HLA-DRβ1* allelic molecules of the major histocompatibility class II (MHC-II), rather than HLA-DRβ3*, β4*, β5* alleles. Complete PPII L 3D structure, a longer distance (26.5 Å ± 1.5 Å) between residues perfectly fitting into HLA-DRβ1*PBR pockets 1 and 9, a gauche − rotamer orientation in p8 TCR-contacting polar residue and a larger volume of polar p2 residues was also found. This data, in association with previously-described p3 and p7 apolar residues having gauche + orientation to form a perfect MHC-II-peptide-TCR complex, determines the stereo-electronic and topochemical characteristics associated with FPLLI immunological memory. - Highlights: • Stereo-electronic and topochemical rules associated with FPLLI immunological memory. • Presence of very high long-lasting antibody titres against Plasmodium falciparum Spz. • Protective memory induction associated with a binding capacity to HLA-DRβ1*. • gauche − rotamer orientation in p8 polar residue is related to is related to immunological memory.

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

Energy Technology Data Exchange (ETDEWEB)

Alba, Martha P.; Suarez, Carlos F. [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Universidad del Rosario, Bogotá D. C. (Colombia); Universidad de Ciencias Aplicadas y Ambientales (UDCA), Bogotá (Colombia); Varela, Yahson [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Patarroyo, Manuel A.; Bermudez, Adriana [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Universidad del Rosario, Bogotá D. C. (Colombia); Patarroyo, Manuel E., E-mail: mepatarr@gmail.com [Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá D. C. (Colombia); Universidad Nacional de Colombia, Bogotá D. C. (Colombia)

2016-09-02

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged 60 days later with a lethal Aotus monkey-adapted P. falciparum strain was found to be associated with preferential high binding capacity to HLA-DRβ1* allelic molecules of the major histocompatibility class II (MHC-II), rather than HLA-DRβ3*, β4*, β5* alleles. Complete PPII{sub L} 3D structure, a longer distance (26.5 Å ± 1.5 Å) between residues perfectly fitting into HLA-DRβ1*PBR pockets 1 and 9, a gauche{sup −} rotamer orientation in p8 TCR-contacting polar residue and a larger volume of polar p2 residues was also found. This data, in association with previously-described p3 and p7 apolar residues having gauche{sup +} orientation to form a perfect MHC-II-peptide-TCR complex, determines the stereo-electronic and topochemical characteristics associated with FPLLI immunological memory. - Highlights: • Stereo-electronic and topochemical rules associated with FPLLI immunological memory. • Presence of very high long-lasting antibody titres against Plasmodium falciparum Spz. • Protective memory induction associated with a binding capacity to HLA-DRβ1*. • gauche{sup −} rotamer orientation in p8 polar residue is related to is related to immunological memory.

Long-lasting solar energetic electron injection during the 26 Dec 2013 widespread SEP event

Science.gov (United States)

Dresing, N.; Klassen, A.; Temmer, M.; Gomez-Herrero, R.; Heber, B.; Veronig, A.

2017-12-01

The solar energetic particle (SEP) event on 26 Dec 2013 was detected all around the Sun by the two STEREO spacecraft and close-to-Earth observers. While the two STEREOs were separated by 59 degrees and situated at the front side of the associated large coronal event, it was a backside-event for Earth. Nevertheless, significant and long-lasting solar energetic electron anisotropies together with long rise times were observed at all three viewpoints, pointing to an extended electron injection. Although the CME-driven shock appears to account for the SEP event at a first glance a more detailed view reveals a more complex scenario: A CME-CME interaction takes place during the very early phase of the SEP event. Furthermore, four hours after the onset of the event, a second component is measured at all three viewpoints on top of the first SEP increase, mainly consisting of high energy particles. We find that the CME-driven shock alone can hardly account for the observed SEP event in total but a trapping scenario together with ongoing particle acceleration is more likely.

Anodal tDCS over the Primary Motor Cortex Facilitates Long-Term Memory Formation Reflecting Use-Dependent Plasticity.

Directory of Open Access Journals (Sweden)

Orjon Rroji

Full Text Available Previous research suggests that anodal transcranial direct current stimulation (tDCS over the primary motor cortex (M1 modulates NMDA receptor dependent processes that mediate synaptic plasticity. Here we test this proposal by applying anodal versus sham tDCS while subjects practiced to flex the thumb as fast as possible (ballistic movements. Repetitive practice of this task has been shown to result in performance improvements that reflect use-dependent plasticity resulting from NMDA receptor mediated, long-term potentiation (LTP-like processes. Using a double-blind within-subject cross-over design, subjects (n=14 participated either in an anodal or a sham tDCS session which were at least 3 months apart. Sham or anodal tDCS (1 mA was applied for 20 min during motor practice and retention was tested 30 min, 24 hours and one week later. All subjects improved performance during each of the two sessions (p < 0.001 and learning gains were similar. Our main result is that long term retention performance (i.e. 1 week after practice was significantly better when practice was performed with anodal tDCS than with sham tDCS (p < 0.001. This effect was large (Cohen's d=1.01 and all but one subject followed the group trend. Our data strongly suggest that anodal tDCS facilitates long-term memory formation reflecting use-dependent plasticity. Our results support the notion that anodal tDCS facilitates synaptic plasticity mediated by an LTP-like mechanism, which is in accordance with previous research.

Patterns of motor activity in the isolated nerve cord of the octopus arm.

Science.gov (United States)

Gutfreund, Yoram; Matzner, Henry; Flash, Tamar; Hochner, Binyamin

2006-12-01

The extremely flexible octopus arm provides a unique opportunity for studying movement control in a highly redundant motor system. We describe a novel preparation that allows analysis of the peripheral nervous system of the octopus arm and its interaction with the muscular and mechanosensory elements of the arm's intrinsic muscular system. First we examined the synaptic responses in muscle fibers to identify the motor pathways from the axial nerve cord of the arm to the surrounding musculature. We show that the motor axons project to the muscles via nerve roots originating laterally from the arm nerve cord. The motor field of each nerve is limited to the region where the nerve enters the arm musculature. The same roots also carry afferent mechanosensory information from the intrinsic muscle to the axial nerve cord. Next, we characterized the pattern of activity generated in the dorsal roots by electrically stimulating the axial nerve cord. The evoked activity, although far reaching and long lasting, cannot alone account for the arm extension movements generated by similar electrical stimulation. The mismatch between patterns of activity in the isolated cord and in an intact arm may stem from the involvement of mechanosensory feedback in natural arm extension.

Human dignity as a component of a long-lasting and widespread conceptual construct.

Science.gov (United States)

Baertschi, Bernard

2014-06-01

For some decades, the concept of human dignity has been widely discussed in bioethical literature. Some authors think that this concept is central to questions of respect for human beings, whereas others are very critical of it. It should be noted that, in these debates, dignity is one component of a long-lasting and widespread conceptual construct used to support a stance on the ethical question of the moral status of an action or being. This construct has been used from Modernity onward to condemn slavery and torture as violations of human dignity. In spelling it out, we can come to a better understanding of what "dignity" means and become aware that there exists a quite useful place for this notion in our ethical thought, albeit a modest one.

DC Motor Drive with PFC Rectifier

Directory of Open Access Journals (Sweden)

Lascu Mihaela

2008-05-01

Full Text Available The goal of this work is to study theperformances of a hybrid controller used to controlDC Motor drive with a single-phase power factorcorrection rectifier. This study is made usingcomputer simulation (Simulink. The first part isdevoted to the control system of the DC Motors. Inthe second part, the design of the hybrid controllerwill be presented. The third part is the design ofthe fast response single-phase boost power factorcorrection rectifier. The last parts are devoted tosimulation and experimental results.

Chronic sleep restriction induces long-lasting changes in adenosine and noradrenaline receptor density in the rat brain.

Science.gov (United States)

Kim, Youngsoo; Elmenhorst, David; Weisshaupt, Angela; Wedekind, Franziska; Kroll, Tina; McCarley, Robert W; Strecker, Robert E; Bauer, Andreas

2015-10-01

Although chronic sleep restriction frequently produces long-lasting behavioural and physiological impairments in humans, the underlying neural mechanisms are unknown. Here we used a rat model of chronic sleep restriction to investigate the role of brain adenosine and noradrenaline systems, known to regulate sleep and wakefulness, respectively. The density of adenosine A1 and A2a receptors and β-adrenergic receptors before, during and following 5 days of sleep restriction was assessed with autoradiography. Rats (n = 48) were sleep-deprived for 18 h day(-1) for 5 consecutive days (SR1-SR5), followed by 3 unrestricted recovery sleep days (R1-R3). Brains were collected at the beginning of the light period, which was immediately after the end of sleep deprivation on sleep restriction days. Chronic sleep restriction increased adenosine A1 receptor density significantly in nine of the 13 brain areas analysed with elevations also observed on R3 (+18 to +32%). In contrast, chronic sleep restriction reduced adenosine A2a receptor density significantly in one of the three brain areas analysed (olfactory tubercle which declined 26-31% from SR1 to R1). A decrease in β-adrenergic receptors density was seen in substantia innominata and ventral pallidum which remained reduced on R3, but no changes were found in the anterior cingulate cortex. These data suggest that chronic sleep restriction can induce long-term changes in the brain adenosine and noradrenaline receptors, which may underlie the long-lasting neurocognitive impairments observed in chronic sleep restriction. © 2015 European Sleep Research Society.

Using anatomical landmark to avoid phrenic nerve injury during balloon-based procedures in atrial fibrillation patients.

Science.gov (United States)

Smith, Nicolina M; Segars, Larry; Kauffman, Travis; Olinger, Anthony B

2017-12-01

Atrial fibrillation (AF) is an arrhythmia which affects as many as 2.7 million Americans. AF should be treated, because it can lead to a four-to-fivefold increased risk of experiencing a stroke. The American College of Cardiology/American Heart Association guidelines for the treatment of drug refractory and symptomatic paroxysmal AF denote catheter ablation as the standard of care. The newest ablation treatment, cryoballoon, uses a cold balloon tip. The biggest risk factor associated with the cryoballoon ablation is phrenic nerve injury (PNI). The purpose of this study is to measure relevant distances from specific landmarks to the right phrenic nerve (RPN) to create a safe zone for physicians. Using 30 cadaveric specimens, we measured laterally from the right superior pulmonary vein orifice (RSPV) to the RPN at the level of the sixth thoracic vertebra and laterally from the lateral border of the sixth thoracic vertebral body (T6) to the RPN. The depth and width of the left atrium (LA) were also measured to establish a cross-sectional area of the LA. The cross-sectional area of the LA was then correlated with the averaged measurements to see if the area of the LA could be a predictor of the location of the RPN. The average distance from the RPN-RSPV was 9.6 mm (range 4.3-18.8 mm). The average RPN-T6 distance was 30.6 mm (range 13.7-49.9 mm). There was a non-significant trend that suggests as the size of the LA increases, the measured distances also increased. Using the lateral border of the sixth thoracic vertebra as a landmark, which can be viewed under fluoroscopy during the procedure, physicians can triangulate the distance to the RSPV and determine the approximate position of the RPN. Furthermore, physicians can perform a preoperative echocardiogram to determine the size of the LA to assist in determining the position of the RPN with the hopes of avoiding injury to the RPN.

Toward an Effective Long-Term Strategy for Preventing Motor Vehicle Crashes and Injuries

Directory of Open Access Journals (Sweden)

Anthony R. Mawson

2014-08-01

Full Text Available Casualties due to motor vehicle crashes (MVCs include some 40,000 deaths each year in the United States and one million deaths worldwide. One strategy that has been recommended for improving automobile safety is to lower speed limits and enforce them with speed cameras. However, motor vehicles can be hazardous even at low speeds whereas properly protected human beings can survive high-speed crashes without injury. Emphasis on changing driver behavior as the focus for road safety improvements has been largely unsuccessful; moreover, drivers today are increasingly distracted by secondary tasks such as cell phone use and texting. Indeed, the true limiting factor in vehicular safety is the capacity of human beings to sense and process information and to make rapid decisions. Given that dramatic reductions in injuries and deaths from MVCs have occurred over the past century due to improvements in safety technology, despite increases in the number of vehicles on the road and miles driven per vehicle, we propose that an effective long-term strategy for reducing MVC-related injury would be continued technological innovation in vehicle design, aimed at progressively removing the driver from routine operational decision-making. Once this is achieved, high rates of speed could be achieved on open highways, with minimal risk of crashes and injury to occupants and pedestrians.

Toward an effective long-term strategy for preventing motor vehicle crashes and injuries.

Science.gov (United States)

Mawson, Anthony R; Walley, E Kenneth

2014-08-11

Casualties due to motor vehicle crashes (MVCs) include some 40,000 deaths each year in the United States and one million deaths worldwide. One strategy that has been recommended for improving automobile safety is to lower speed limits and enforce them with speed cameras. However, motor vehicles can be hazardous even at low speeds whereas properly protected human beings can survive high-speed crashes without injury. Emphasis on changing driver behavior as the focus for road safety improvements has been largely unsuccessful; moreover, drivers today are increasingly distracted by secondary tasks such as cell phone use and texting. Indeed, the true limiting factor in vehicular safety is the capacity of human beings to sense and process information and to make rapid decisions. Given that dramatic reductions in injuries and deaths from MVCs have occurred over the past century due to improvements in safety technology, despite increases in the number of vehicles on the road and miles driven per vehicle, we propose that an effective long-term strategy for reducing MVC-related injury would be continued technological innovation in vehicle design, aimed at progressively removing the driver from routine operational decision-making. Once this is achieved, high rates of speed could be achieved on open highways, with minimal risk of crashes and injury to occupants and pedestrians.

Electrical stimulation of transplanted motoneurons improves motor unit formation

Science.gov (United States)

Liu, Yang; Grumbles, Robert M.

2014-01-01

Motoneurons die following spinal cord trauma and with neurological disease. Intact axons reinnervate nearby muscle fibers to compensate for the death of motoneurons, but when an entire motoneuron pool dies, there is complete denervation. To reduce denervation atrophy, we have reinnervated muscles in Fisher rats from local transplants of embryonic motoneurons in peripheral nerve. Since growth of axons from embryonic neurons is activity dependent, our aim was to test whether brief electrical stimulation of the neurons immediately after transplantation altered motor unit numbers and muscle properties 10 wk later. All surgical procedures and recordings were done in anesthetized animals. The muscle consequences of motoneuron death were mimicked by unilateral sciatic nerve section. One week later, 200,000 embryonic day 14 and 15 ventral spinal cord cells, purified for motoneurons, were injected into the tibial nerve 10–15 mm from the gastrocnemii muscles as the only neuron source for muscle reinnervation. The cells were stimulated immediately after transplantation for up to 1 h using protocols designed to examine differential effects due to pulse number, stimulation frequency, pattern, and duration. Electrical stimulation that included short rests and lasted for 1 h resulted in higher motor unit counts. Muscles with higher motor unit counts had more reinnervated fibers and were stronger. Denervated muscles had to be stimulated directly to evoke contractions. These results show that brief electrical stimulation of embryonic neurons, in vivo, has long-term effects on motor unit formation and muscle force. This muscle reinnervation provides the opportunity to use patterned electrical stimulation to produce functional movements. PMID:24848463

Dopaminergic mesocortical projections to M1: role in motor learning and motor cortex plasticity

Directory of Open Access Journals (Sweden)

Jonas Aurel Hosp

2013-10-01

Full Text Available Although the architecture of a dopaminergic (DA system within the primary motorcortex (M1 was well characterized anatomically, its functional significance remainedobscure for a long time. Recent studies in rats revealed that the integrity ofdopaminergic fibers in M1 is a prerequisite for successful acquisition of motor skills.This essential contribution of DA for motor learning is plausible as it modulates M1circuitry at multiple levels thereby promoting plastic changes that are required forinformation storage: at the network level, DA increases cortical excitability andenhances the stability of motor maps. At the cellular level, DA induces the expressionof learning related genes via the transcription factor c-fos. At the level of synapses,DA is required for the formation of long-term potentiation (LTP, a mechanism thatlikely is a fingerprint of a motor memory trace within M1. Dopaminergic fibersinnervating M1 originate within the midbrain, precisely the ventral tegmental area(VTA and the medial portion of substantia nigra (SN. Thus, they could be part of themeso-cortico-limibic pathway – a network that provides information about saliencyand motivational value of an external stimulus and is commonly referred as

Short- and long-term effects of selective dorsal rhizotomy on gross motor function in ambulatory children with spastic diplegia Clinical article

NARCIS (Netherlands)

van Schie, P.E.M.; Schothorst, M.; Dallmeijer, A.J.; Vermeulen, R.J.; van Ouwerkerk, W.J.R.; Strijers, R.L.M.; Becher, J.G.

2011-01-01

Object. The primary aim of this prospective cohort study was to evaluate the short-term (1 year) and long-term (mean 6 years) effects of selective dorsal rhizotomy (SDR) on gross motor function and spasticity in ambulatory children with spastic diplegia. Secondary aims were to investigate side

Left is right and right is wrong: fluorodeoxyglucose uptake in left hemi-diaphragm due to right phrenic nerve palsy

International Nuclear Information System (INIS)

Joshi, Prathamesh; Lele, Vikram

2013-01-01

A 36-year-old Indian man, a recently diagnosed case of the right lung carcinoma underwent fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) for staging of the malignancy. PET/CT showed increased FDG uptake in the right lung mass, consistent with the known primary tumor. Right hemidiaphragm was found to be elevated on CT, suggesting right diaphragmatic paresis. The PET scan demonstrated asymmetric, intense FDG uptake in the left hemidiaphragm and accessory muscles of respiration, which was possibly due to compensatory increased workload related to contralateral right diaphragmatic paresis. The right diaphragmatic paresis was hypothesized to be caused by phrenic nerve palsy by right lung neoplasm. (author)

Left is right and right is wrong: Fluorodeoxyglucose uptake in left hemi-diaphragm due to right phrenic nerve palsy.

Science.gov (United States)

Joshi, Prathamesh; Lele, Vikram

2013-01-01

A 36-year-old Indian man, a recently diagnosed case of the right lung carcinoma underwent fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) for staging of the malignancy. PET/CT showed increased FDG uptake in the right lung mass, consistent with the known primary tumor. Right hemidiaphragm was found to be elevated on CT, suggesting right diaphragmatic paresis. The PET scan demonstrated asymmetric, intense FDG uptake in the left hemidiaphragm and accessory muscles of respiration, which was possibly due to compensatory increased workload related to contralateral right diaphragmatic paresis. The right diaphragmatic paresis was hypothesized to be caused by phrenic nerve palsy by right lung neoplasm.

Acute exercise improves motor memory consolidation in preadolescent children

DEFF Research Database (Denmark)

Lundbye-Jensen, Jesper; Skriver, Kasper Christen; Nielsen, Jens Bo

2017-01-01

protocols following motor skill practice in a school setting can also improve long-term retention of motor memory in preadolescent children. Methods: Seventy-seven pre-adolescent children (age 10.5 ± 0.75 (SD)) participated in the study. Prior to the main experiment age, BMI, fitness status and general...... immediately after motor skill acquisition facilitates long-term motor memory in pre-adolescent children, presumably by promoting memory consolidation. The results also demonstrate that the effects can be accomplished in a school setting. The positive effect of both a team game (i.e., FLB) and running......Objective: The ability to acquire new motor skills is essential both during childhood and later in life. Recent studies have demonstrated that an acute bout of exercise can improve motor memory consolidation in adults. The objective of the present study was to investigate whether acute exercise...

Behavior of high efficiency electric motors; Comportamiento de motores electricos de alta eficiencia

Energy Technology Data Exchange (ETDEWEB)

Bonett, Austin H. [IEEE, (United States)

2001-09-01

The energy efficiency is one of the main parameters in the design of the industrial motors of general purpose; nevertheless, it is avoided that it is at the cost of the reliability or to the global performance of the motor. Exist user groups of this equipment that consider that, in the search of a greater efficiency, the useful life period is diminished and the characteristics of operation of the motor are affected. During the past last years, the author has studied the aspects of quality and reliability, as well as the operative advantages of the high efficiency motors and written down the increasing interest for these aspects. Also he has detected that a great number of users has realized that, additionally to the obvious energy saving, the efficient motor offers a greater reliability and a longer useful life in most of the industrial applications. The objective of this article is to present the differences in the quality levels, reliability and operation parameters of high efficiency squirrel cage type electrical motors with those of the motors of standard manufacture. [Spanish] La eficiencia energetica es uno de los principales parametros en el diseno de los motores industriales de proposito general; sin embargo, se evita que sea a costa de la confiabilidad o del desempeno global del motor. Existen grupos de usuarios de estos equipos que consideran que, en la busqueda de una mayor eficiencia, se disminuye el periodo de vida util y se afectan las caracteristicas de operacion del motor. Durante los ultimos anos, el autor ha estudiado los aspectos de calidad y confiabilidad, asi como las ventajas operativas de los motores de alta eficiencia y anotado el incremento del interes por estos aspectos. Tambien ha detectado que un gran numero de usuarios se ha dado cuenta que, adicionalmente a los obvios ahorros de energia, el motor eficiente ofrece una mayor confiabilidad y una vida util mas larga en la mayoria de las aplicaciones industriales. El objetivo de este

θ-burst stimulation of the cerebellum interferes with internal representations of sensory-motor information related to eye movements in humans.

Science.gov (United States)

Colnaghi, Silvia; Ramat, Stefano; D'Angelo, Egidio; Cortese, Andrea; Beltrami, Giorgio; Moglia, Arrigo; Versino, Maurizio

2011-12-01

Continuous theta-burst stimulation (cTBS) applied over the cerebellum exerts long-lasting effects by modulating long-term synaptic plasticity, which is thought to be the basis of learning and behavioral adaptation. To investigate the impact of cTBS over the cerebellum on short-term sensory-motor memory, we recorded in two groups of eight healthy subject each the visually guided saccades (VGSs), the memory-guided saccades (MGSs), and the multiple memory-guided saccades (MMGSs), before and after cTBS (cTBS group) or simulated cTBS (control group). In the cTBS group, cTBS determined hypometria of contralateral centrifugal VGSs and worsened the accuracy of MMGS bilaterally. In the control group, no significant differences were found between the two recording sessions. These results indicate that cTBS over the cerebellum causes eye movement effects that last longer than the stimulus duration. The VGS contralateral hypometria suggested that we eventually inhibited the fastigial nucleus on the stimulated side. MMGSs in normal subjects have a better final accuracy with respect to MGSs. Such improvement is due to the availability in MMGSs of the efference copy of the initial reflexive saccade directed toward the same peripheral target, which provides a sensory-motor information that is memorized and then used to improve the accuracy of the subsequent volitional memory-guided saccade. Thus, we hypothesize that cTBS disrupted the capability of the cerebellum to make an internal representation of the memorized sensory-motor information to be used after a short interval for forward control of saccades.

High Working Memory Load Increases Intracortical Inhibition in Primary Motor Cortex and Diminishes the Motor Affordance Effect.

Science.gov (United States)

Freeman, Scott M; Itthipuripat, Sirawaj; Aron, Adam R

2016-05-18

Motor affordances occur when the visual properties of an object elicit behaviorally relevant motor representations. Typically, motor affordances only produce subtle effects on response time or on motor activity indexed by neuroimaging/neuroelectrophysiology, but sometimes they can trigger action itself. This is apparent in "utilization behavior," where individuals with frontal cortex damage inappropriately grasp affording objects. This raises the possibility that, in healthy-functioning individuals, frontal cortex helps ensure that irrelevant affordance provocations remain below the threshold for actual movement. In Experiment 1, we tested this "frontal control" hypothesis by "loading" the frontal cortex with an effortful working memory (WM) task (which ostensibly consumes frontal resources) and examined whether this increased EEG measures of motor affordances to irrelevant affording objects. Under low WM load, there were typical motor affordance signatures: an event-related desynchronization in the mu frequency and an increased P300 amplitude for affording (vs nonaffording) objects over centroparietal electrodes. Contrary to our prediction, however, these affordance measures were diminished under high WM load. In Experiment 2, we tested competing mechanisms responsible for the diminished affordance in Experiment 1. We used paired-pulse transcranial magnetic stimulation over primary motor cortex to measure long-interval cortical inhibition. We found greater long-interval cortical inhibition for high versus low load both before and after the affording object, suggesting that a tonic inhibition state in primary motor cortex could prevent the affordance from provoking the motor system. Overall, our results suggest that a high WM load "sets" the motor system into a suppressed state that mitigates motor affordances. Is an irrelevant motor affordance more likely to be triggered when you are under low or high cognitive load? We examined this using physiological measures

Design and characterization of piezoelectric ultrasonic motors

Science.gov (United States)

Yener, Serra

This thesis presents modeling and prototype fabrication and characterization of new types of piezoelectric ultrasonic micromotors. Our approach in designing these piezoelectric motors was: (i) to simplify the structure including the poling configuration of piezoelectric elements used in the stator and (ii) to reduce the number of components in order to decrease the cost and enhance the driving reliability. There are two different types of piezoelectric motors designed throughout this research. The first of these designs consists of a metal tube, on which two piezoelectric ceramic plates poled in thickness direction, were bonded. Two orthogonal bending modes of the hollow cylinder were superimposed resulting in a rotational vibration. Since the structure and poling configuration of the active piezoelectric elements used in the stator are simple, this motor structure is very suitable for miniaturization. Moreover, a single driving source can excite two bending modes at the same time, thus generate a wobble motion. Three types of prototypes are included in this design. The piezoelectric stator structure is the same for all. However, the dimensions of the motors are reduced by almost 50 percent. Starting with a 10 mm long stator, we reached to 4 mm in the last prototype. The initial diameter was 2.4 mm, which was reduced to 1.6 mm. In the final design, the rotor part of the motor was changed resulting in the reduction in the number of components. In terms of driving circuit, a single driving source was enough to run the motors and a conventional switching power supply type resonant L-C circuit was used. A simple motor structure with a simple driving circuit were combined successfully and fabricated inexpensively. The second design is a shear type piezoelectric linear motor. The behavior of a single rectangular piezoelectric shear plate was analyzed and after optimizing the dimensions and the mode characteristics, a prototype was fabricated. The prototype consists of

Recent developments in esophageal motor disorders

NARCIS (Netherlands)

Beaumont, Hanneke; Boeckxstaens, Guy

2007-01-01

PURPOSE OF REVIEW: Every year more insight into the pathogenesis and treatment of esophageal motor disorders is obtained. This review highlights some interesting literature published in this area during the last year. RECENT FINDINGS: Longitudinal and circular muscle contractions act in a well

A single footshock causes long-lasting hypoactivity in unknown environments that is dependent on the development of contextual fear conditioning.

Science.gov (United States)

Daviu, Núria; Fuentes, Silvia; Nadal, Roser; Armario, Antonio

2010-09-01

Exposure to a single session of footshocks induces long-lasting inhibition of activity in unknown environments that markedly differ from the shock context. Interestingly, these effects are not necessarily associated to an enhanced anxiety and interpretation of this hypoactivity remains unclear. In the present experiment we further studied this phenomenon in male Sprague-Dawley rats. In a first experiment, a session of three shocks resulted in hypoactivity during exposure, 6-12days later, to three different unknown environments. This altered behaviour was not accompanied by a greater hypothalamic-pituitary-adrenal (HPA) activation, although greater HPA activation paralleling higher levels of freezing was observed in the shock context. In a second experiment we used a single shock and two procedures, one with pre-exposure to the context before the shock and another with immediate shock that did not induce contextual fear conditioning. Hypoactivity and a certain level of generalization of fear (freezing) to the unknown environments only appeared in the group that developed fear conditioning, but no evidence for enhanced anxiety in the elevated plus-maze was found in any group. The results suggest that if animals are able to associate an aversive experience with a distinct unknown environment, they would display more cautious behaviour in any unknown environment and such strategy persists despite repeated experience with different environments. This long-lasting cautious behaviour was not associated to greater HPA response to the unknown environment that was however observed in the shock context. The present findings raised some concerns about interpretation of long-lasting behavioural changes caused by brief stressors. Copyright 2010 Elsevier Inc. All rights reserved.

Correspondence in relation to the case report "Capnography as an aid in localizing the phrenic nerve in brachial plexus surgery. Technical note." published in May issue of Journal of Brachial Plexus and Peripheral Nerve Injury

Directory of Open Access Journals (Sweden)

Bhakta Pradipta

2008-10-01

Full Text Available Abstract Comment on 'Capnography as an aid in localizing the phrenic nerve in brachial plexus surgery. Technical note' Bhagat H, Agarwal A, Sharma MS Journal of Brachial Plexus and Peripheral Nerve Injury 2008, 3:14 (22 May 2008

Motor Skill Learning and Corticospinal Excitability

DEFF Research Database (Denmark)

Christiansen, Lasse

Background Motor skill learning (MSL) is the persistent increase in performance of a skill obtained through practice. This process is associated with changes throughout the central nervous system. One of these is a change in corticospinal excitability (CSE) assessable with Transcranial Magnetic...... a novel visuomotor skill. I hypothesized that changes in CSE accompanying long-term motor practice relate to the process of learning rather than repetitive practice on an acquired skill and investigated this by incrementally increasing task difficulty and thus postponing saturation of learning....... Furthermore, we aimed to investigate the feasibility of applying paired associative stimulation to the investigation of learning-dependent motor cortical plasticity by comparing the transient increase in CSE accompanying motor skill learning to the associative plasticity induced by pairing electrical motor...

The effectiveness of robotic training depends on motor task characteristics.

Science.gov (United States)

Marchal-Crespo, Laura; Rappo, Nicole; Riener, Robert

2017-12-01

Previous research suggests that the effectiveness of robotic training depends on the motor task to be learned. However, it is still an open question which specific task's characteristics influence the efficacy of error-modulating training strategies. Motor tasks can be classified based on the time characteristics of the task, in particular the task's duration (discrete vs. continuous). Continuous tasks require movements without distinct beginning or end. Discrete tasks require fast movements that include well-defined postures at the beginning and the end. We developed two games, one that requires a continuous movement-a tracking task-and one that requires discrete movements-a fast reaching task. We conducted an experiment with thirty healthy subjects to evaluate the effectiveness of three error-modulating training strategies-no guidance, error amplification (i.e., repulsive forces proportional to errors) and haptic guidance-on self-reported motivation and learning of the continuous and discrete games. Training with error amplification resulted in better motor learning than haptic guidance, besides the fact that error amplification reduced subjects' interest/enjoyment and perceived competence during training. Only subjects trained with error amplification improved their performance after training the discrete game. In fact, subjects trained without guidance improved the performance in the continuous game significantly more than in the discrete game, probably because the continuous task required greater attentional levels. Error-amplifying training strategies have a great potential to provoke better motor learning in continuous and discrete tasks. However, their long-lasting negative effects on motivation might limit their applicability in intense neurorehabilitation programs.

Visualization of Sensory Neurons and Their Projections in an Upper Motor Neuron Reporter Line.

Science.gov (United States)

Genç, Barış; Lagrimas, Amiko Krisa Bunag; Kuru, Pınar; Hess, Robert; Tu, Michael William; Menichella, Daniela Maria; Miller, Richard J; Paller, Amy S; Özdinler, P Hande

2015-01-01

Visualization of peripheral nervous system axons and cell bodies is important to understand their development, target recognition, and integration into complex circuitries. Numerous studies have used protein gene product (PGP) 9.5 [a.k.a. ubiquitin carboxy-terminal hydrolase L1 (UCHL1)] expression as a marker to label sensory neurons and their axons. Enhanced green fluorescent protein (eGFP) expression, under the control of UCHL1 promoter, is stable and long lasting in the UCHL1-eGFP reporter line. In addition to the genetic labeling of corticospinal motor neurons in the motor cortex and degeneration-resistant spinal motor neurons in the spinal cord, here we report that neurons of the peripheral nervous system are also fluorescently labeled in the UCHL1-eGFP reporter line. eGFP expression is turned on at embryonic ages and lasts through adulthood, allowing detailed studies of cell bodies, axons and target innervation patterns of all sensory neurons in vivo. In addition, visualization of both the sensory and the motor neurons in the same animal offers many advantages. In this report, we used UCHL1-eGFP reporter line in two different disease paradigms: diabetes and motor neuron disease. eGFP expression in sensory axons helped determine changes in epidermal nerve fiber density in a high-fat diet induced diabetes model. Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation. Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage. Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

Cat odor causes long-lasting contextual fear conditioning and increased pituitary-adrenal activation, without modifying anxiety.

Science.gov (United States)

Muñoz-Abellán, Cristina; Daviu, Nuria; Rabasa, Cristina; Nadal, Roser; Armario, Antonio

2009-10-01

A single exposure to a cat or cat odors has been reported by some groups to induce contextual and auditory fear conditioning and long-lasting changes in anxiety-like behaviour, but there is no evidence for parallel changes in biological stress markers. In the present study we demonstrated in male rats that exposure to a novel environment containing a cloth impregnated with cat fur odor resulted in avoidance of the odor, lower levels of activity and higher pituitary-adrenal (PA) response as compared to those exposed to the novel environment containing a clean cloth, suggesting increased levels of stress in the former animals. When re-exposed 9 days later to the same environment with a clean cloth, previously cat fur exposed rats again showed avoidance of the cloth area and lower levels of activity, suggesting development of contextual fear conditioning, which again was associated with a higher PA activation. In contrast, unaltered both anxiety-like behaviour and PA responsiveness to an elevated plus-maze were found 7 days after cat odor exposure. It is concluded that: (i) PA activation is able to reflect both the stressful properties of cat fur odor and odor-induced contextual fear conditioning; (ii) development of cat odor-induced contextual fear conditioning is independent of the induction of long-lasting changes in anxiety-like behaviour; and (iii) greater PA activation during exposure to the odor context is not explained by non-specific sensitization of the PA axis caused by previous exposure to cat fur odor.

Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?

Science.gov (United States)

Watson, Charles; Tvrdik, Petr

2018-04-16

The spinal accessory nerve arises from motor neurons in the upper cervical spinal cord. The axons of these motor neurons exit dorsal to the ligamentum denticulatum and form the spinal accessory nerve. The nerve ascends in the spinal subarachnoid space to enter the posterior cranial fossa through the foramen magnum. The spinal accessory nerve then turns caudally to exit through the jugular foramen alongside the vagus and glossopharyngeal nerves, and then travels to supply the sternomastoid and trapezius muscles in the neck. The unusual course of the spinal accessory nerve has long prompted speculation that it is not a typical spinal motor nerve and that it might represent a caudal remnant of the branchial motor system. Our cell lineage tracing data, combined with images from public databases, show that the spinal accessory motor neurons in the mouse transiently express Phox2b, a transcription factor that is required for development of brain stem branchial motor nuclei. While this is strong prima facie evidence that the spinal accessory motor neurons should be classified as branchial motor, the evolutionary history of these motor neurons in anamniote vertebrates suggests that they may be considered to be an atypical branchial group that possesses both branchial and somatic characteristics. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

On line protection systems for induction motors

International Nuclear Information System (INIS)

Colak, I.; Celik, H.; Sefa, I.; Demirbas, S.

2005-01-01

Protection of induction motors is very important since they are widely used in industry for many applications due to their high robustness, reliability, low cost and maintenance, high efficiency and long service life. So, protecting these motors is crucial for operations. This paper presents a combined protection approach for induction motors. To achieve this, the electrical values of the induction motor were measured with sensitivity ±1% through a data acquisition card and processed with software developed in Visual C++. An on line protection system for induction motors was achieved easily and effectively. The experimental results have shown that the induction motor was protected against the possible problems faced during the operation. The software developed for this protection provides flexible and reliable media for operators and their motors. It is expected that the motor protection achieved in this study might be faster than the classical techniques and also may be applied to larger motors easily after small modifications of the software

Short-Term Dosage Regimen for Stimulation-Induced Long-Lasting Desynchronization

Directory of Open Access Journals (Sweden)

Thanos Manos

2018-04-01

Full Text Available In this paper, we computationally generate hypotheses for dose-finding studies in the context of desynchronizing neuromodulation techniques. Abnormally strong neuronal synchronization is a hallmark of several brain disorders. Coordinated Reset (CR stimulation is a spatio-temporally patterned stimulation technique that specifically aims at disrupting abnormal neuronal synchrony. In networks with spike-timing-dependent plasticity CR stimulation may ultimately cause an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and neuronal synchrony. This long-lasting desynchronization was theoretically predicted and verified in several pre-clinical and clinical studies. We have shown that CR stimulation with rapidly varying sequences (RVS robustly induces an anti-kindling at low intensities e.g., if the CR stimulation frequency (i.e., stimulus pattern repetition rate is in the range of the frequency of the neuronal oscillation. In contrast, CR stimulation with slowly varying sequences (SVS turned out to induce an anti-kindling more strongly, but less robustly with respect to variations of the CR stimulation frequency. Motivated by clinical constraints and inspired by the spacing principle of learning theory, in this computational study we propose a short-term dosage regimen that enables a robust anti-kindling effect of both RVS and SVS CR stimulation, also for those parameter values where RVS and SVS CR stimulation previously turned out to be ineffective. Intriguingly, for the vast majority of parameter values tested, spaced multishot CR stimulation with demand-controlled variation of stimulation frequency and intensity caused a robust and pronounced anti-kindling. In contrast, spaced CR stimulation with fixed stimulation parameters as well as singleshot CR stimulation of equal integral duration failed to improve the stimulation outcome. In the model network under consideration, our short-term dosage regimen enables to robustly induce

Short-Term Dosage Regimen for Stimulation-Induced Long-Lasting Desynchronization.

Science.gov (United States)

Manos, Thanos; Zeitler, Magteld; Tass, Peter A

2018-01-01

In this paper, we computationally generate hypotheses for dose-finding studies in the context of desynchronizing neuromodulation techniques. Abnormally strong neuronal synchronization is a hallmark of several brain disorders. Coordinated Reset (CR) stimulation is a spatio-temporally patterned stimulation technique that specifically aims at disrupting abnormal neuronal synchrony. In networks with spike-timing-dependent plasticity CR stimulation may ultimately cause an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and neuronal synchrony. This long-lasting desynchronization was theoretically predicted and verified in several pre-clinical and clinical studies. We have shown that CR stimulation with rapidly varying sequences (RVS) robustly induces an anti-kindling at low intensities e.g., if the CR stimulation frequency (i.e., stimulus pattern repetition rate) is in the range of the frequency of the neuronal oscillation. In contrast, CR stimulation with slowly varying sequences (SVS) turned out to induce an anti-kindling more strongly, but less robustly with respect to variations of the CR stimulation frequency. Motivated by clinical constraints and inspired by the spacing principle of learning theory, in this computational study we propose a short-term dosage regimen that enables a robust anti-kindling effect of both RVS and SVS CR stimulation, also for those parameter values where RVS and SVS CR stimulation previously turned out to be ineffective. Intriguingly, for the vast majority of parameter values tested, spaced multishot CR stimulation with demand-controlled variation of stimulation frequency and intensity caused a robust and pronounced anti-kindling. In contrast, spaced CR stimulation with fixed stimulation parameters as well as singleshot CR stimulation of equal integral duration failed to improve the stimulation outcome. In the model network under consideration, our short-term dosage regimen enables to robustly induce long

The detectability of the origin of the inferior phrenic artery by paging method on multidetector-row CT angiography

International Nuclear Information System (INIS)

Terayama, Koshi

2005-01-01

We evaluated the ability to detect the origin of the inferior phrenic artery (IPA) by paging method on multidetector-row computed tomography (CT) angiography. In 104 patients who underwent multidetector-row CT, detectability of the origin of the IPA was assessed. In addition, in 30 patients in whom arteriographic study was performed, the IPA findings on multidetector-row CT were compared with those on arteriography. In 100 patients (96%) the origin of the right IPA was demonstrated with multidetector-row CT and in 93 patients (89%) the origin of the left IPA was demonstrated. CT angiographic findings concurred with arteriographic findings in all 30 patients (100%) who underwent arteriographic study. In conclusion, paging method on multidetector-row CT angiography provides valuable anatomical information regarding IPA. (author)

Training Lymnaea in the presence of a predator scent results in a long-lasting ability to form enhanced long-term memory.

Science.gov (United States)

Forest, Jeremy; Sunada, Hiroshi; Dodd, Shawn; Lukowiak, Ken

2016-06-01

Lymnaea exposed to crayfish effluent (CE) gain an enhanced ability to form long-term memory (LTM). We test the hypothesis that a single CE exposure and operant conditioning training leads to long lasting changes in the capability of snails to form LTM when tested in pond water four weeks later. We trained both juvenile and adult snails with a single 0.5 h training session in CE and show that LTM was present 24 h later. Snails trained in a similar manner in just pond water show no LTM. We then asked if such training in CE conferred enhanced memory forming capabilities on these snails four weeks later. That is, would LTM be formed in these snails four weeks later following a single 0.5 h training session in pond water? We found that both adult and juvenile snails previously trained in CE one month previously had enhanced LTM formation abilities. The injection of a DNA methylation blocker, 5-AZA, prior to training in adult snails blocked enhanced LTM formation four weeks later. Finally, this enhanced LTM forming ability was not passed on to the next generation of snails.

Comparing Recalibration Strategies for Electroencephalography-Based Decoders of Movement Intention in Neurological Patients with Motor Disability.

Science.gov (United States)

López-Larraz, Eduardo; Ibáñez, Jaime; Trincado-Alonso, Fernando; Monge-Pereira, Esther; Pons, José Luis; Montesano, Luis

2017-12-17

Motor rehabilitation based on the association of electroencephalographic (EEG) activity and proprioceptive feedback has been demonstrated as a feasible therapy for patients with paralysis. To promote long-lasting motor recovery, these interventions have to be carried out across several weeks or even months. The success of these therapies partly relies on the performance of the system decoding movement intentions, which normally has to be recalibrated to deal with the nonstationarities of the cortical activity. Minimizing the recalibration times is important to reduce the setup preparation and maximize the effective therapy time. To date, a systematic analysis of the effect of recalibration strategies in EEG-driven interfaces for motor rehabilitation has not yet been performed. Data from patients with stroke (4 patients, 8 sessions) and spinal cord injury (SCI) (4 patients, 5 sessions) undergoing two different paradigms (self-paced and cue-guided, respectively) are used to study the performance of the EEG-based classification of motor intentions. Four calibration schemes are compared, considering different combinations of training datasets from previous and/or the validated session. The results show significant differences in classifier performances in terms of the true and false positives (TPs) and (FPs). Combining training data from previous sessions with data from the validation session provides the best compromise between the amount of data needed for calibration and the classifier performance. With this scheme, the average true (false) positive rates obtained are 85.3% (17.3%) and 72.9% (30.3%) for the self-paced and the cue-guided protocols, respectively. These results suggest that the use of optimal recalibration schemes for EEG-based classifiers of motor intentions leads to enhanced performances of these technologies, while not requiring long calibration phases prior to starting the intervention.

Maternal-pup interaction disturbances induce long-lasting changes in the newborn rat pulmonary vasculature.

Science.gov (United States)

Shifrin, Yulia; Sadeghi, Sina; Pan, Jingyi; Jain, Amish; Fajardo, Andres F; McNamara, Patrick J; Belik, Jaques

2015-11-15

The factors accounting for the pathological maintenance of a high pulmonary vascular (PV) resistance postnatally remain elusive, but neonatal stressors may play a role in this process. Cross-fostering in the immediate neonatal period is associated with adult-onset vascular and behavioral changes, likely triggered by early-in-life stressors. In hypothesizing that fostering newborn rats induces long-lasting PV changes, we evaluated them at 14 days of age during adulthood and compared the findings with animals raised by their biological mothers. Fostering resulted in reduced maternal-pup contact time when compared with control newborns. At 2 wk of age, fostered rats exhibited reduced pulmonary arterial endothelium-dependent relaxation secondary to downregulation of tissue endothelial nitric oxide synthase expression and tetrahydrobiopterin deficiency-induced uncoupling. These changes were associated with neonatal onset-increased ANG II receptor type 1 expression, PV remodeling, and right ventricular hypertrophy that persisted into adulthood. The pulmonary arteries of adult-fostered rats exhibited a higher contraction dose response to ANG II and thromboxane A2, the latter of which was abrogated by the oxidant scavenger Tempol. In conclusion, fostering-induced neonatal stress induces long-standing PV changes modulated via the renin-angiotensin system. Copyright © 2015 the American Physiological Society.

Rasagiline as an adjunct to levodopa in patients with Parkinson's disease and motor fluctuations (LARGO, Lasting effect in Adjunct therapy with Rasagiline Given Once daily, study): a randomised, double-blind, parallel-group trial.

OpenAIRE

Rascol, O.; Brooks, D.J.; Melamed, E.; Oertel, W.; Poewe, W.; Stocchi, F.; Tolosa, E.; LARGO study group

2005-01-01

Lancet. 2005 Mar 12-18;365(9463):947-54. Rasagiline as an adjunct to levodopa in patients with Parkinson's disease and motor fluctuations (LARGO, Lasting effect in Adjunct therapy with Rasagiline Given Once daily, study): a randomised, double-blind, parallel-group trial. Rascol O, Brooks DJ, Melamed E, Oertel W, Poewe W, Stocchi F, Tolosa E; LARGO study group. Clinical Investigation Centre, Department of Clinical Pharmacology, University Hospital, Toulouse, France. ...

Altered synaptic plasticity in Tourette's syndrome and its relationship to motor skill learning.

Directory of Open Access Journals (Sweden)

Valerie Cathérine Brandt

Full Text Available Gilles de la Tourette syndrome is a neuropsychiatric disorder characterized by motor and phonic tics that can be considered motor responses to preceding inner urges. It has been shown that Tourette patients have inferior performance in some motor learning tasks and reduced synaptic plasticity induced by transcranial magnetic stimulation. However, it has not been investigated whether altered synaptic plasticity is directly linked to impaired motor skill acquisition in Tourette patients. In this study, cortical plasticity was assessed by measuring motor-evoked potentials before and after paired associative stimulation in 14 Tourette patients (13 male; age 18-39 and 15 healthy controls (12 male; age 18-33. Tic and urge severity were assessed using the Yale Global Tic Severity Scale and the Premonitory Urges for Tics Scale. Motor learning was assessed 45 minutes after inducing synaptic plasticity and 9 months later, using the rotary pursuit task. On average, long-term potentiation-like effects in response to the paired associative stimulation were present in healthy controls but not in patients. In Tourette patients, long-term potentiation-like effects were associated with more and long-term depression-like effects with less severe urges and tics. While motor learning did not differ between patients and healthy controls 45 minutes after inducing synaptic plasticity, the learning curve of the healthy controls started at a significantly higher level than the Tourette patients' 9 months later. Induced synaptic plasticity correlated positively with motor skills in healthy controls 9 months later. The present study confirms previously found long-term improvement in motor performance after paired associative stimulation in healthy controls but not in Tourette patients. Tourette patients did not show long-term potentiation in response to PAS and also showed reduced levels of motor skill consolidation after 9 months compared to healthy controls. Moreover

Combined Use of an Occlusion Balloon Catheter and a Microcatheter for Embolization of the Unselectable Right Inferior Phrenic Artery Supplying Hepatocellular Carcinoma

International Nuclear Information System (INIS)

Miyayama, Shiro; Matsui, Osamu; Taki, Keiichi; Minami, Tetsuya; Ito, Chiharu; Shinmura, Rieko; Takamatsu, Shigeyuki; Kobayashi, Miki; Notsumata, Kazuo

2004-01-01

We report the combined use of an occlusion balloon catheter and a microcatheter for transcatheter arterial embolization (TAE) of hepatocellular carcinoma (HCC) fed by the unselectable right inferior phrenic artery (IPA). In one case, HCC was fed by the reconstructed right IPA via a small branch arising from the proximate portion of the celiac artery. In another, the tumor was fed by the right IPA that had been previously embolized with coils. TAE was successfully performed through a microcatheter placed in the celiac artery immediately proximal to the occluding balloon catheter of the celiac trunk and coil embolization of the left gastric artery

Motor current signature analysis for determining operational readiness of motor-operated valves (MOVs)

International Nuclear Information System (INIS)

Kryter, R.C.; Haynes, H.D.

1987-01-01

Motor current signature analysis (MCSA) is a novel diagnostic process for condition monitoring of electric-motor-driven mechanical equipment (e.g., pumps, motor-operated valves, compressors, and processing machinery). The MCSA process identifies, characterizes, and trends over time the instantaneous load variations of mechanical equipment in order to diagnose changes in the condition of the equipment (e.g., due to degradation or service wear), which, if allowed to continue, may lead to failure. It monitors the instantaneous variations (noise content) in the electric current flowing through the power leads to the electric motor that drives the equipment. The motor itself thereby acts as a transducer, sensing both large and small, long-term and rapid, mechanical load variations and converting them to variations in the induced current generated in the motor windings. This motor current noise signature is detected, amplified, and further processed as needed to examine its time domain and frequency domain (spectral) characteristics. The operational principles of MCSA and the nonintrusive data collection apparatus and procedure used with MOVs will be described. Data collected from MOVs in both laboratory and in-plant environments will also be shown to illustrate the ability of MCSA to ''see'' the detailed inner workings of the valve and operator and thus to detect degraded performance at an incipient stage. (Set of 18 vugraphs)

Intrasurgical mapping of complex motor function in the superior frontal gyrus.

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Martino, J; Gabarrós, A; Deus, J; Juncadella, M; Acebes, J J; Torres, A; Pujol, J

2011-04-14

A lesion to the superior frontal gyrus (SFG) has been associated with long-lasting deficits in complex motor functions. The aim of this study was to analyze the functional role of the SFG by means of electrical cortical stimulation. Direct intraoperative electrical stimulation was used in a group of 21 subjects with lesions within or close to the SFG while they performed three motor tasks that require high skills or bimanual synergy. The results were compared to functional magnetic resonance imaging (fMRI). Ninety-four of the 98 (94.9%) labels identified were located on the convexity surface of the SFG and only four (4.1%) labels were located on the middle surface of the SFG. Areas of blockage of the three tasks were identified in six of the 12 (50%) hemispheres with lesions that had infiltrated the SFG, compared to all 10 of the 10 hemispheres (100%) with lesions that spared the SFG. The difference between these two proportions was statistically significant (P=0.015). fMRI activation was mainly located on the medial aspect of the SFG. We show that the convexity surface of the SFG has an important role in bilateral control of complex movements and in bimanual coordination. The infiltration of the posterior part of the SFG by a lesion disturbs some of the complex hand motor functions, which may be assumed by the contralesional homologous area. Finally, the current study emphasizes the discrepancies between fMRI and intraoperative electrical stimulation maps in complex hand motor function. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Short and long term outcome of bilateral pallidal stimulation in chorea-acanthocytosis.

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Marie Miquel

Full Text Available Chorea-acanthocytosis (ChAc is a neuroacanthocytosis syndrome presenting with severe movement disorders poorly responsive to drug therapy. Case reports suggest that bilateral deep brain stimulation (DBS of the ventro-postero-lateral internal globus pallidus (GPi may benefit these patients. To explore this issue, the present multicentre (n=12 retrospective study collected the short and long term outcome of 15 patients who underwent DBS.Data were collected in a standardized way 2-6 months preoperatively, 1-5 months (early and 6 months or more (late after surgery at the last follow-up visit (mean follow-up: 29.5 months.Motor severity, assessed by the Unified Huntington's Disease Rating Scale-Motor Score, UHDRS-MS, was significantly reduced at both early and late post-surgery time points (mean improvement 54.3% and 44.1%, respectively. Functional capacity (UHDRS-Functional Capacity Score was also significantly improved at both post-surgery time points (mean 75.5% and 73.3%, respectively, whereas incapacity (UHDRS-Independence Score improvement reached significance at early post-surgery only (mean 37.3%. Long term significant improvement of motor symptom severity (≥ 20 % from baseline was observed in 61.5 % of the patients. Chorea and dystonia improved, whereas effects on dysarthria and swallowing were variable. Parkinsonism did not improve. Linear regression analysis showed that preoperative motor severity predicted motor improvement at both post-surgery time points. The most serious adverse event was device infection and cerebral abscess, and one patient died suddenly of unclear cause, 4 years after surgery.This study shows that bilateral DBS of the GPi effectively reduces the severity of drug-resistant hyperkinetic movement disorders such as present in ChAc.

Cocaine Self-Administration Produces Long-Lasting Alterations in Dopamine Transporter Responses to Cocaine

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Siciliano, Cody A.; Fordahl, Steve C.

2016-01-01

Cocaine addiction is a debilitating neuropsychiatric disorder characterized by uncontrolled cocaine intake, which is thought to be driven, at least in part, by cocaine-induced deficits in dopamine system function. A decreased ability of cocaine to elevate dopamine levels has been repeatedly observed as a consequence of cocaine use in humans, and preclinical work has highlighted tolerance to cocaine's effects as a primary determinant in the development of aberrant cocaine taking behaviors. Here we determined that cocaine self-administration in rats produced tolerance to the dopamine transporter-inhibiting effects of cocaine in the nucleus accumbens core, which was normalized following a 14 or 60 d abstinence period; however, although these rats appeared to be similar to controls, a single self-administered infusion of cocaine at the end of abstinence, even after 60 d, fully reinstated tolerance to cocaine's effects. A single cocaine infusion in a naive rat had no effect on cocaine potency, demonstrating that cocaine self-administration leaves the dopamine transporter in a “primed” state, which allows for cocaine-induced plasticity to be reinstated by a subthreshold cocaine exposure. Further, reinstatement of cocaine tolerance was accompanied by decreased cocaine-induced locomotion and escalated cocaine intake despite extended abstinence from cocaine. These data demonstrate that cocaine leaves a long-lasting imprint on the dopamine system that is activated by re-exposure to cocaine. Further, these results provide a potential mechanism for severe cocaine binge episodes, which occur even after sustained abstinence from cocaine, and suggest that treatments aimed at transporter sites may be efficacious in promoting binge termination following relapse. SIGNIFICANCE STATEMENT Tolerance is a DSM-V criterion for substance abuse disorders. Abusers consistently show reduced subjective effects of cocaine concomitant with reduced effects of cocaine at its main site of action