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Sample records for reversible thalamic ischemia

  1. Ophthalmoplegic migraine with reversible thalamic ischemia by Tc-99m ethylcysteinate dimer brain SPECT

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    Kim, Jong Ho; Shin, Dong Jin; Kang, Sung Soo [Gachon Medical School, Gil Medical Center, Inchon (Korea, Republic of)

    1999-07-01

    Two patients presented with ophthalmoplegic migraine (OM) underwent EEG, Brain-MRI, cerebral angiography, and Tc-99m ECD SPECT during an attack. Follow-up SPECT was performed after neurologic symptoms resolved. In both cases, SPECT during an attack of ophthalmoplegia and headache demonstrated a significantly decreased regional cerebral blood flow in the thalamus to the side of ophthalmoplegia, which was normalized on the follow-up SPECT during a symptom free recovery phase (Lesion to Non-lesion thalamic ratio=1.19 to 0.96 and 1.16 to 0.98, respectively). The other roentgenographic and laboratory findings were normal. These findings are suggestive the ischemia in the perforators of PCA results in third nerve palsy because the portion of oculomotor nerve behind the cavernous sinus derives its blood supply from small perforating branches of the basilar and PCA. Matched ictal hypoperfusion of the thalamus to the site of ophthalmoplegic migraine is suggestive of the ischemic neuropathy as an etiology of OM.

  2. CT perfusion during delayed cerebral ischemia after subarachnoid hemorrhage: distinction between reversible ischemia and ischemia progressing to infarction

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    Cremers, Charlotte H.P. [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, PO Box 85500, Utrecht, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vos, Pieter C. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Schaaf, Irene C. van der; Velthuis, Birgitta K.; Dankbaar, Jan Willem [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vergouwen, Mervyn D.I.; Rinkel, Gabriel J.E. [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, PO Box 85500, Utrecht, Utrecht (Netherlands)

    2015-09-15

    Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) can be reversible or progress to cerebral infarction. In patients with a deterioration clinically diagnosed as DCI, we investigated whether CT perfusion (CTP) can distinguish between reversible ischemia and ischemia progressing to cerebral infarction. From a prospectively collected series of aSAH patients, we included those with DCI, CTP on the day of clinical deterioration, and follow-up imaging. In qualitative CTP analyses (visual assessment), we calculated positive and negative predictive value (PPV and NPV) with 95 % confidence intervals (95%CI) of a perfusion deficit for infarction on follow-up imaging. In quantitative analyses, we compared perfusion values of the least perfused brain tissue between patients with and without infarction by using receiver-operator characteristic curves and calculated a threshold value with PPV and NPV for the perfusion parameter with the highest area under the curve. In qualitative analyses of 33 included patients, 15 of 17 patients (88 %) with and 6 of 16 patients (38 %) without infarction on follow-up imaging had a perfusion deficit during clinical deterioration (p = 0.002). Presence of a perfusion deficit had a PPV of 71 % (95%CI: 48-89 %) and NPV of 83 % (95%CI: 52-98 %) for infarction on follow-up. Quantitative analyses showed that an absolute minimal cerebral blood flow (CBF) threshold of 17.7 mL/100 g/min had a PPV of 63 % (95%CI: 41-81 %) and a NPV of 78 % (95%CI: 40-97 %) for infarction. CTP may differ between patients with DCI who develop infarction and those who do not. For this purpose, qualitative evaluation may perform marginally better than quantitative evaluation. (orig.)

  3. Curcumin reverses neurochemical, histological and immuno-histochemical alterations in the model of global brain ischemia

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    Glaura Fernandes Teixeira de Alcântara

    2017-01-01

    Full Text Available Curcumin, a curcuminoid from Curcuma longa, presents antioxidant and anti-inflammatory actions and, among pathological changes of cerebral ischemic injury, inflammation is an important one. The objectives were to study the neuroprotective action of curcumin, in a model of global ischemia. Male Wistar rats (sham-operated, ischemic untreated and ischemic treated with curcumin, 25 or 50 mg/kg, p.o. were anesthesized and their carotid arteries occluded, for 30 min. The SO group had the same procedure, except for carotid occlusion. In the 1st protocol, animals were treated 1 h before ischemia and 24 h later; and in the 2nd protocol, treatments began 1 h before ischemia, continuing for 7 days. Twenty four hours after the last administration, animals were euthanized and measurements for striatal monoamines were performed, at the 1st and 7th days after ischemia, as well as histological and immunohistochemical assays in hippocampi. We showed in both protocols, depletions of DA and its metabolites (DOPAC and HVA, in the ischemic group, but these effects were reversed by curcumin. Additionally, a decrease seen in 5-HT contents, 1 day after ischemia, was also reversed by curcumin. This reversion was not seen 7 days later. On the other hand, a decrease observed in NE levels, at the 7th day, was totally reversed by curcumin. Furthermore, curcumin treatments increased neuronal viability and attenuated the immunoreactivity for COX-2 and TNF-alpha, in the hippocampus in both protocols. We showed that curcumin exerts neuroprotective actions, in a model of brain ischemia that are probably related to its anti-inflammatory activity.

  4. Intravenous digital subtraction angiography investigation of reversible cerebral ischemia

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    Pistolesi, G.F.; Maso, R.; Filosto, L.; Piovan, E.; Morgante, D.; Taddei, G.; Tonegutti, M.; Portuese, A.

    1986-01-01

    The brachio-cephalic, carotid, vertebral and intra-cranial vessels of 497 patients presenting reversible ischemic attacks (R.I.A) were evaluated with venous digital subtraction angiography (V.D.S.A.). Alterations of the vascular wall were observed in 289/497 (58.2%) patients, of whom 60% presented multiple locations (539 lesions): obstruction (12%), stenosis >50% (29%), stenosis 50%. The incidence of vascular lesions was higher (p [fr

  5. Augmentation of limb perfusion and reversal of tissue ischemia produced by ultrasound-mediated microbubble cavitation.

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    Belcik, J Todd; Mott, Brian H; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J; Ammi, Azzdine; Linden, Joel M; Lindner, Jonathan R

    2015-04-01

    Ultrasound can increase tissue blood flow, in part, through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation and sought to characterize the biological mediators. Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in nonischemic mice after unilateral 10-minute exposure to intermittent ultrasound alone (mechanical index, 0.6 or 1.3) or ultrasound with lipid microbubbles (2×10(8) IV). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (Pultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3- and 10-fold higher than control for mechanical index 0.6 and 1.3, respectively; Pultrasound and microbubbles by 70% (Pultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40%-50% reduction in flow), ultrasound (mechanical index, 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control nonischemic limb. Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of endothelial nitric oxide synthase. © 2015 American Heart Association, Inc.

  6. Thalamic VPM nucleus in the behaving monkey. III. Effects of reversible inactivation by lidocaine on thermal and mechanical discrimination.

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    Duncan, G H; Bushnell, M C; Oliveras, J L; Bastrash, N; Tremblay, N

    1993-11-01

    1. The present study evaluates the necessity of the ventroposterior medial thalamic nucleus (VPM) for discrimination of the intensity of noxious heating, innocuous cooling, and innocuous tactile (airpuff) stimulation of the maxillary skin. 2. Two rhesus monkeys were trained to detect small differences (Lidocaine hydrochloride (2%) was microinjected into regions of thalamus where single-unit recordings had identified neuronal responses to the noxious heating and/or cooling stimuli. The effectiveness of the anesthetic blockade was monitored by multiunit recordings using microelectrodes positioned 1-3 mm from the orifice of the injection cannula. The monkey's ability to detect near-threshold changes in stimulus intensity was compared before and after each injection. 3. During six experimental sessions, single injections of 1-4 microliters lidocaine near the dorsomedial border of VPM did not significantly alter the monkey's ability to detect small changes in the intensity of noxious heat, cool, airpuff, or visual stimuli despite neurophysiological evidence that spontaneous neuronal activity was blocked within parts of VPM. 4. During three experiments, dual simultaneous microinjections of lidocaine (delivered through 2 microcannulae separated by approximately 1 mm) resulted in profound deficits in noxious heat discrimination, with lesser deficits in cool and airpuff discrimination; visual discrimination was never altered. Monitoring of adjacent microelectrodes revealed that although activity ventral to the injection sites was blocked, activity in medial thalamic nuclei, implicated in nociceptive processing, was probably not altered by these injections. 5. These data suggest that VPM is important for the perception of noxious and innocuous thermal stimuli as well as for the perception of tactile stimuli. However, considering the ineffectiveness of small single microinjections of lidocaine, it appears that some critical proportion of VPM must be inactivated to disrupt

  7. Identification of Reversible Disruption of the Human Blood-Brain Barrier Following Acute Ischemia.

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    Simpkins, Alexis N; Dias, Christian; Leigh, Richard

    2016-09-01

    Animal models of acute cerebral ischemia have demonstrated that diffuse blood-brain barrier (BBB) disruption can be reversible after early reperfusion. However, irreversible, focal BBB disruption in humans is associated with hemorrhagic transformation in patients receiving intravenous thrombolytic therapy. The goal of this study was to use a magnetic resonance imaging biomarker of BBB permeability to differentiate these 2 forms of BBB disruption. Acute stroke patients imaged with magnetic resonance imaging before, 2 hours after, and 24 hours after treatment with intravenous tissue-type plasminogen activator were included. The average BBB permeability of the acute ischemic region before and 2 hours after treatment was calculated using a T2* perfusion-weighted source images. Change in average permeability was compared with percent reperfusion using linear regression. Focal regions of maximal BBB permeability from the pretreatment magnetic resonance imaging were compared with the occurrence of parenchymal hematoma (PH) formation on the 24-hour magnetic resonance imaging scan using logistic regression. Signals indicating reversible BBB permeability were detected in 18/36 patients. Change in average BBB permeability correlated inversely with percent reperfusion (P=0.006), indicating that early reperfusion is associated with decreased BBB permeability, whereas sustained ischemia is associated with increased BBB disruption. Focal regions of maximal BBB permeability were significantly associated with subsequent formation of PH (P=0.013). This study demonstrates that diffuse, mild BBB disruption in the acutely ischemic human brain is reversible with reperfusion. This study also confirms prior findings that focal severe BBB disruption confers an increased risk of hemorrhagic transformation in patients treated with intravenous tissue-type plasminogen activator. © 2016 American Heart Association, Inc.

  8. Reversibility of retinal ischemia due to central retinal artery occlusion by hyperbaric oxygen

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    Hadanny A

    2016-12-01

    Full Text Available Amir Hadanny,1,2 Amit Maliar,1 Gregory Fishlev,1 Yair Bechor,1 Jacob Bergan,1 Mony Friedman,1 Isaac Avni,2,3 Shai Efrati1,2,4,5 1Sagol Center for Hyperbaric Medicine and Research, Assaf Harofeh Medical Center, Zerifin, Israel; 2Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel; 3Opthalmology Department, Assaf Harofeh Medical Center, Zeirifin, Israel; 4Research and Development Unit, Assaf Harofeh Medical Center, Zerifin, Israel; 5Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel Purpose: Ischemic retinal damage can be reversed by hyperbaric oxygen therapy (HBOT as long as irreversible infarction damage has not developed. However, the time window till irreversible damage develops is still unknown. The study aim was to evaluate the effect of HBOT and determine possible markers for irreversible retinal damage.Materials and methods: Retrospective analysis of 225 patients treated with HBOT for central retinal artery occlusion (CRAO in 1999–2015. One hundred and twenty-eight patients fulfilled inclusion/exclusion criteria: age >18 years, symptoms <20 hours, and best-corrected visual acuity (BCVA <0.5 logMAR.Results: Time delay from symptoms to treatment was 7.8±3.8 hours. The BCVA was significantly improved after HBOT, from 2.14±0.50 to 1.61±0.78 (P<0.0001. The proportion of patients with clinically meaningful visual improvement was significantly higher in patients without cherry-red spot (CRS compared to patients with CRS at presentation (86.0% vs 57.6%, P<0.0001. The percentage of patients with final BCVA better than 1.0 was also significantly higher in patients without CRS vs patients with CRS at presentation (61.0% vs 7.1%, P<0.0001. There was no correlation between CRS and the time from symptoms. HBOT was found to be safe, and only 5.5% of patients had minor, reversible, adverse events.Conclusion: HBOT is an effective treatment for non-arteritic CRAO as long as CRS has not formed. The fundus findings, rather

  9. Reversal of retinal and optic disc ischemia in a patient with sickle cell trait and glaucoma secondary to traumatic hyphema.

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    Wax, M B; Ridley, M E; Magargal, L E

    1982-07-01

    A 14-year-old black boy with sickle cell trait, who sustained a traumatic hyphema, developed moderately elevated intraocular pressure that failed to respond to carbonic anhydrase inhibitors and osmotic agents. On the tenth postinjury day, a sudden increased cupping of the optic disc and partial central retinal artery obstruction caused painless loss of vision. Reversal of the cupping, the retinal ischemia, and the intraocular pressure was documented following anterior chamber paracentesis, and visual acuity returned to 6/6. Pathophysiology of the posterior ischemia is discussed. This case documents the potentially debilitating course of traumatic hyphema in "benign" sickle cell trait and its avoidance with proper management. The authors endorse recent suggestions for careful observation of any sickle cell patient with traumatic hyphema, and recommend anterior chamber paracentesis, supplemental oxygen, and avoidance of osmotic agents, if secondary glaucoma develops following the initial trauma.

  10. Reversible blockade of complex I or inhibition of PKCβ reduces activation and mitochondria translocation of p66Shc to preserve cardiac function after ischemia.

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    Meiying Yang

    Full Text Available Excess mitochondrial reactive oxygen species (mROS play a vital role in cardiac ischemia reperfusion (IR injury. P66Shc, a splice variant of the ShcA adaptor protein family, enhances mROS production by oxidizing reduced cytochrome c to yield H2O2. Ablation of p66Shc protects against IR injury, but it is unknown if and when p66Shc is activated during cardiac ischemia and/or reperfusion and if attenuating complex I electron transfer or deactivating PKCβ alters p66Shc activation during IR is associated with cardioprotection.Isolated guinea pig hearts were perfused and subjected to increasing periods of ischemia and reperfusion with or without amobarbital, a complex I blocker, or hispidin, a PKCβ inhibitor. Phosphorylation of p66Shc at serine 36 and levels of p66Shc in mitochondria and cytosol were measured. Cardiac functional variables and redox states were monitored online before, during and after ischemia. Infarct size was assessed in some hearts after 120 min reperfusion.Phosphorylation of p66Shc and its translocation into mitochondria increased during reperfusion after 20 and 30 min ischemia, but not during ischemia only, or during 5 or 10 min ischemia followed by 20 min reperfusion. Correspondingly, cytosolic p66Shc levels decreased during these ischemia and reperfusion periods. Amobarbital or hispidin reduced phosphorylation of p66Shc and its mitochondrial translocation induced by 30 min ischemia and 20 min reperfusion. Decreased phosphorylation of p66Shc by amobarbital or hispidin led to better functional recovery and less infarction during reperfusion.Our results show that IR activates p66Shc and that reversible blockade of electron transfer from complex I, or inhibition of PKCβ activation, decreases p66Shc activation and translocation and reduces IR damage. These observations support a novel potential therapeutic intervention against cardiac IR injury.

  11. Hypertensive thalamic hemorrhage

    International Nuclear Information System (INIS)

    Munaka, Masahiro; Nishikawa, Michio; Hirai, Osamu; Kaneko, Takaaki; Watanabe, Syu; Fukuma, Jun; Handa, Hajime

    1988-01-01

    In the past six years, we have had experience with 40 patients with hypertensive thalamic hemorrhages, as verified by CT scan at our hospital within 24 hours. These patients were classified into the following three groups according to the location of the bleeding point and the size of the hematoma: (1) anteromedial (4 cases), (2) posterolateral (16 cases), and (3) massive (20 cases). The (1) and (2) hematomas were small (less than 3 cm in diameter), while those in (3) were large (more than 3 cm in diameter). Twenty cases (50% of all the thalamic hematomas) were small hematomas. The characteristic clinical symptoms of the anteromedial type were a mild disturbance of consciousness and thalamic dementia, while those of the posterolateral type were motor and sensory disturbance, and thalamic aphasia, respectively. Twenty cases (50%) were large hematomas. The clinical symptoms of these cases were mainly consciousness disturbance; 7 of them expired. Based on this experience, it may be considered that the patients whose hematoma size was larger than 3 cm had a poor prognosis and that the patients with the posterolateral type had a poor functional diagnosis. (author)

  12. Local fibrinolytic therapy for patients with cerebral embolism and reversibility of cerebral ischemia in ultra-acute stage

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    Koizumi, Takayuki

    1993-01-01

    The present study was undertaken to determine candidates for fibrinolytic therapy in cerebral embolism. Forty-three patients were examined by single photon emission computed tomography (SPECT) using 99m c-d, hexamethyl-propylene-amine oxime (HM-PAO) or N-isopropyl p[ 123 I]-iodoamphetamine ( 123 I-IMP) just before and after intra-arterial local fibrinolytic therapy. Regional cerebellar ratio (R/Ce) and asymmetry index (AI) were calculated just before the treatment (n=9). Quantitative analysis was performed after the treatment (n=all). SPECT images taken within 24 hours after the treatment fell into three patters: normal perfusion, hypoperfusion, and hyperperfusion. Patients showing normal perfusion pattern after complete recanalization developed no or smaller infarction on CT scans. However, patients showing either hypoperfusion or hyperperfusion developed large infarction. Regions with R/Ce ratio of 0.3 or smaller and/or AI of 1.5 or greater were irreversible, which was associated with cerebral infarction regardless of the duration of ischemia. On the other hand, regions with R/Ce of 0.5 or greater or AI of 1.2 or smaller were reversible with no association of infarction. Intra-arterial local fibrinolytic therapy seems to be helpful for patients with slight reduction of regional cerebral blood flow (i.e., R/Ce>0.5, AI 1.5). These findings indicate that SPECT is capable of determining reversibility of ischemic region, thereby contributing to better management of patients with acute cerebral embolism. (N.K.)

  13. Increased Regional Epicardial Fat Volume Associated with Reversible Myocardial Ischemia in Patients with Suspected Coronary Artery Disease

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    Khawaja, Tuba; Greer, Christine; Thadani, Samir R.; Kato, Tomoko S.; Bhatia, Ketan; Shimbo, Daichi; Konkak, Andrew; Bokhari, Sabahat; Einstein, Andrew J.; Schulze, P. Christian

    2015-01-01

    Epicardial adipose tissue is a source of pro-inflammatory cytokines and has been linked to the development of coronary artery disease. No study has systematically assessed the relationship between local epicardial fat volume (EFV) and myocardial perfusion defects. We analyzed EFV in patients undergoing SPECT myocardial perfusion imaging combined with computed tomography (CT) for attenuation correction. Low-dose CT without contrast was performed in 396 consecutive patients undergoing SPECT imaging for evaluation of coronary artery disease. Regional thickness, cross-sectional areas, and total EFV were assessed. 295 patients had normal myocardial perfusion scans and 101 had abnormal perfusion scans. Mean EFVs in normal, ischemic, and infarcted hearts were 99.8 ± 82.3 cm3, 156.4 ± 121.9 cm3, and 96.3 ± 102.1 cm3, respectively (P < 0.001). Reversible perfusion defects were associated with increased local EFV compared to normal perfusion in the distribution of the right (69.2 ± 51.5 vs 46.6 ± 32.0 cm3; P = 0.03) and left anterior descending coronary artery (87.1 ± 76.4 vs 46.7 ± 40.6 cm3; P = 0.005). Our results demonstrate increased regional epicardial fat in patients with active myocardial ischemia compared to patients with myocardial scar or normal perfusion on nuclear perfusion scans. Our results suggest a potential role for cardiac CT to improve risk stratification in patients with suspected coronary artery disease. PMID:25339129

  14. Midline thalamic reuniens lesions improve executive behaviors.

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    Prasad, J A; Abela, A R; Chudasama, Y

    2017-03-14

    The role of the thalamus in complex cognitive behavior is a topic of increasing interest. Here we demonstrate that lesions of the nucleus reuniens (NRe), a midline thalamic nucleus interconnected with both hippocampal and prefrontal circuitry, lead to enhancement of executive behaviors typically associated with the prefrontal cortex. Rats were tested on four behavioral tasks: (1) the combined attention-memory (CAM) task, which simultaneously assessed attention to a visual target and memory for that target over a variable delay; (2) spatial memory using a radial arm maze, (3) discrimination and reversal learning using a touchscreen operant platform, and (4) decision-making with delayed outcomes. Following NRe lesions, the animals became more efficient in their performance, responding with shorter reaction times but also less impulsively than controls. This change, combined with a decrease in perseverative responses, led to focused attention in the CAM task and accelerated learning in the visual discrimination task. There were no observed changes in tasks involving either spatial memory or value-based decision making. These data complement ongoing efforts to understand the role of midline thalamic structures in human cognition, including the development of thalamic stimulation as a therapeutic strategy for acquired cognitive disabilities (Schiff, 2008; Mair et al., 2011), and point to the NRe as a potential target for clinical intervention. Published by Elsevier Ltd.

  15. Rapid reversal of human intestinal ischemia-reperfusion induced damage by shedding of injured enterocytes and reepithelialisation.

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    Joep P M Derikx

    Full Text Available BACKGROUND: Intestinal ischemia-reperfusion (IR is a phenomenon related to physiological conditions (e.g. exercise, stress and to pathophysiological events (e.g. acute mesenteric ischemia, aortic surgery. Although intestinal IR has been studied extensively in animals, results remain inconclusive and data on human intestinal IR are scarce. Therefore, an experimental harmless model for human intestinal IR was developed, enabling us to clarify the sequelae of human intestinal IR for the first time. METHODS AND FINDINGS: In 30 patients undergoing pancreatico-duodenectomy we took advantage of the fact that in this procedure a variable length of jejunum is removed. Isolated jejunum (5 cm was subjected to 30 minutes ischemia followed by reperfusion. Intestinal Fatty Acid Binding Protein (I-FABP arteriovenous concentration differences across the bowel segment were measured before and after ischemia to assess epithelial cell damage. Tissue sections were collected after ischemia and at 25, 60 and 120 minutes reperfusion and stained with H&E, and for I-FABP and the apoptosis marker M30. Bonferroni's test was used to compare I-FABP differences. Mean (SEM arteriovenous concentration gradients of I-FABP across the jejunum revealed rapidly developing epithelial cell damage. I-FABP release significantly increased from 290 (46 pg/ml before ischemia towards 3,997 (554 pg/ml immediately after ischemia (p<0.001 and declined gradually to 1,143 (237 pg/ml within 1 hour reperfusion (p<0.001. Directly after ischemia the intestinal epithelial lining was microscopically normal, while subepithelial spaces appeared at the villus tip. However, after 25 minutes reperfusion, enterocyte M30 immunostaining was observed at the villus tip accompanied by shedding of mature enterocytes into the lumen and loss of I-FABP staining. Interestingly, within 60 minutes reperfusion the epithelial barrier resealed, while debris of apoptotic, shedded epithelial cells was observed in the lumen

  16. Dexmedetomidine improves neurologic outcome from incomplete ischemia in the rat. Reversal by the alpha 2-adrenergic antagonist atipamezole.

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    Hoffman, W E; Kochs, E; Werner, C; Thomas, C; Albrecht, R F

    1991-08-01

    Dexmedetomidine is an alpha 2-adrenergic agonist that decreases central sympathetic activity and reduces the anesthetic requirement for halothane. We evaluated the effect of dexmedetomidine on neurologic and histopathologic outcome from incomplete cerebral ischemia in the rat. Anesthesia was maintained with a 25-micrograms.kg-1.h-1 fentanyl infusion combined with 70% nitrous oxide. Incomplete ischemia was produced by unilateral carotid artery ligation combined with hemorrhagic hypotension to 35 mmHg for 30 min. Arterial blood gas tensions, pH, and head temperature were maintained at normal levels during the experiment. Four ischemic groups were tested: group 1 (n = 15) received an intraperitoneal (ip) saline injection (control); group 2 (n = 10) received an ip injection of 10 micrograms/kg dexmedetomidine 30 min before ischemia; group 3 (n = 10) received 100 micrograms/kg dexmedetomidine; and group 4 (n = 10) received 100 micrograms/kg dexmedetomidine plus 1 mg/kg atipamezole (an alpha 2-adrenergic antagonist). Neurologic outcome was evaluated for 3 days using a graded deficit score. Histopathology was evaluated in coronal section in caudate and hippocampal tissue segments. Dexmedetomidine (10 and 100 micrograms/kg) significantly decreased plasma catecholamines and improved neurologic and histopathologic outcome in a dose-dependent manner compared to control rats (P less than 0.05). Atipamezole abolished the decrease in catecholamines and the improvement in outcome seen with dexmedetomidine, confirming that these effects were mediated by alpha 2-adrenergic receptors. It is concluded that alpha 2-adrenoreceptor stimulation decreases sympathetic activity and decreases ischemic injury in a model of incomplete cerebral ischemia.

  17. New developments in secondary stroke prevention: impact of the European/Australasian Stroke Prevention in Reversible Ischemia Trial (ESPRIT) on clinical management.

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    Lutsep, Helmi L

    2007-01-01

    Secondary stroke prevention is an important goal of poststroke patient treatment. Various pharmacologic approaches have been advocated, but the relative efficacy and safety of these regimens has remained the subject of much debate. Recently released data from the European/Australasian Stroke Prevention in Reversible Ischemia Trial (ESPRIT) indicated that combination therapy with aspirin and extended-release dipyridamole was more effective than aspirin monotherapy, and probably more effective than anticoagulants, for the prevention of cerebrovascular events after a stroke or transient ischemic attack. When viewed in light of results of earlier trials, these findings confirmed that combination aspirin plus extended-release dipyridamole therapy improved outcomes in these patients and is a recommended option for poststroke patient treatment.

  18. CF findings of bowel infarction in 56 surgical patients, 5 of whom with reversible ischemia; Aspetti alla tomografia computerizzata dell'infarto intestinale. 56 pazienti sottoposti a interventi chirurgico di cui 5 con ischemia mesenterica reversibile.

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    Salzano, A.; De Rosa, A.; Carbone, M.; Ginolfi, F.; Rossi, E.; Amodio, F. [Naples Univ. Federico 2. (Italy). Ist. di Scienze Radiologiche; Muto, M.; Tuccillo, M. [Azienda Sanitaria di Rilievo Nazionale A. Cardarelli, Naples (Italy). Servizio di Neuroradiologia

    1999-04-01

    Bowel infarction is a rare and typical condition of the elderly; despite improvements in diagnostic imaging and vascular surgery, bowel infarction remains a major cause of acute abdomen, with mortality rates ranging 70-80%. Diagnosis on often late because clinical signs, laboratory data and radiologic findings are a specific. The authors investigated radiographic and particular CT patterns of intestinal infraction in 56 patients submitted to surgery within 12 hours of admission. We also report the CT findings of 5 of these patients who had reversible mesenteric ischemia. CT is more sensitive than radiography and does not exhibit the limitations of angiography (i.e., invasiveness, radiation exposure and complex organization). Therefore CT can presently be considered the method of choice in patients with suspected bowel infarction. [Italian] L'infarto intestinale rappresenta una malattia rara e tipica del soggeto anziano; nonostante il notevole perfezionamento delle tecniche di diagnostica per immagini e il progresso della chirurgia vascolare, rimane ancora oggi una delle piu' temibili condizioni di addome acuto, con mortalita' superiore al 70-80%. Il riconoscimento diagnostico e' tardivo per l'aspecificita' dei dati di laboratorio, dei segni clinici e degli esami radiologici. La TC presenta maggiore afficacia diagnostica rispetto all'esame radiografico diretto e non ha limiti che caratterizzano l'angiografia, quali l'invasivita', radioesposizione e complessita' organizzativa: attualmente la metodica TC puo' essere indicata come indagine di scelta in pazienti con sospetto infarto intestinale.

  19. Altered thalamic functional connectivity in multiple sclerosis

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    Liu, Yaou; Liang, Peipeng; Duan, Yunyun; Huang, Jing; Ren, Zhuoqiong; Jia, Xiuqin [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Dong, Huiqing; Ye, Jing [Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Shi, Fu-Dong [Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052 (China); Butzkueven, Helmut [Department of Medicine, University of Melbourne, Parkville 3010 (Australia); Li, Kuncheng, E-mail: kunchengli55@gmail.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China)

    2015-04-15

    Highlights: •We demonstrated decreased connectivity between thalamus and cortical regions in MS. •Increased intra- and inter-thalamic connectivity was also observed in MS. •The increased functional connectivity is attenuated by increasing disease duration. -- Abstract: Objective: To compare thalamic functional connectivity (FC) in patients with multiple sclerosis (MS) and healthy controls (HC), and correlate these connectivity measures with other MRI and clinical variables. Methods: We employed resting-state functional MRI (fMRI) to examine changes in thalamic connectivity by comparing thirty-five patients with MS and 35 age- and sex-matched HC. Thalamic FC was investigated by correlating low frequency fMRI signal fluctuations in thalamic voxels with voxels in all other brain regions. Additionally thalamic volume fraction (TF), T2 lesion volume (T2LV), EDSS and disease duration were recorded and correlated with the FC changes. Results: MS patients were found to have a significantly lower TF than HC in bilateral thalami. Compared to HC, the MS group showed significantly decreased FC between thalamus and several brain regions including right middle frontal and parahippocampal gyri, and the left inferior parietal lobule. Increased intra- and inter-thalamic FC was observed in the MS group compared to HC. These FC alterations were not correlated with T2LV, thalamic volume or lesions. In the MS group, however, there was a negative correlation between disease duration and inter-thalamic connectivity (r = −0.59, p < 0.001). Conclusion: We demonstrated decreased FC between thalamus and several cortical regions, while increased intra- and inter-thalamic connectivity in MS patients. These complex functional changes reflect impairments and/or adaptations that are independent of T2LV, thalamic volume or presence of thalamic lesions. The negative correlation between disease duration and inter-thalamic connectivity could indicate an adaptive role of thalamus that is

  20. Pulmonary Venous Diastolic Flow Reversal and Flash Pulmonary Edema During Management of Ongoing Myocardial Ischemia with Intraaortic Balloon Pump.

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    Murray, Davoy; Peng, Yong G

    2015-10-15

    A 65-year-old man was admitted for acute coronary syndrome with depressed left ventricular function and moderate aortic regurgitation. He was managed with an intraaortic balloon pump for circulatory support before coronary artery bypass grafting and subsequently developed flash pulmonary edema with an associated rare finding of diastolic pulmonary venous flow reversal. In this report, we provide a review of intraaortic balloon pump use in current clinical practice and elaborate on the pathophysiology of an uncommon pulmonary venous flow pattern found in our patient.

  1. Mesenteric Ischemia

    Directory of Open Access Journals (Sweden)

    Shannon Toohey

    2016-07-01

    Full Text Available Audience: This simulation session is appropriate for emergency medicine residents at any level or medical students. Introduction: Mesenteric ischemia is a rare, but serious cause of abdominal pain. Practitioners must recognize the diagnosis quickly. The clinical course rapidly advances from bowel ischemia to infarction, sepsis, and frequently death. Mesenteric ischemia accounts for approximately 1% of all ED cases of abdominal pain in the elderly, but the mortality is as high as 93%. Objectives: At the end of this simulation session, the learner will: 1 Recognize signs and symptoms of mesenteric ischemia; 2 order appropriately imaging and labs in the workup of an elderly patient with abdominal pain; 3 manage a patient with mesenteric ischemia, a rare, but serious cause of abdominal pain in the elderly; 4 discuss anchoring bias, specifically related to patients referred to the ED with an established diagnosis by outside specialists. Methods: This educational session is a high-fidelity simulation.

  2. Language disturbances from mesencephalo-thalamic infarcts

    International Nuclear Information System (INIS)

    Lazzarino, L.G.; Nicolai, A.; Valassi, F.; Biasizzo, E.

    1991-01-01

    The authors report the cases of two patients with CT-documented paramedian mesencephalo-thalamic infarcts, showing language disturbances. The first patient showed a non fluent, transcortical motor-like aphasia, the other had a fluent but severely paraphasic language disorder. The CT study disclosed that it was the dorso-median thalamic nucleus that was mostly involved in both cases. These findings agree with a few previous pathological studies suggesting that the paramedian thalamic nuclei, particlularly the dorso-median nucleus may play some role in language disturbances. However the anatomical basis for thalamic aphasia remains speculative, taking into account the importantce of cortical connections in the origin of subcortical neuropsychological disturbances. (orig.)

  3. Pathogenesis and prognosis of bilateral thalamic infarction

    International Nuclear Information System (INIS)

    Nakase, Taizen; Ogura, Naoko; Maeda, Tetsuya; Yamazaki, Takashi; Kameda, Tomoaki; Sato, Yuichi; Nagata, Ken

    2008-01-01

    Only a few reports have discussed the detailed clinical symptoms and pathogenesis of bilateral thalamic infarction. The thalamus is composed of different functional nuclei and supplied by vessels containing several variations from the main arteries, leading to difficulty in the precise evaluation of bilateral thalamic infarction. In the present study, we assessed the prognosis of bilateral thalamic infarction based on the distribution of stroke lesions. From among the consecutive ischemic stroke patients admitted to hospital between April 2001 and March 2005, cases of acute bilateral thalamic infarction were selected for this study (n=9; 65.1±13.6 y.o.). The stroke lesions and vascular abnormalities were investigated by magnetic resonance imaging and magnetic resonance angiography on admission. Outcome was evaluated from the modified Rankin scale (mRS) at discharge. Good outcome patients (mRS 0-2; n=5) showed memory disturbance, cognitive impairment and hypersomnia. On the other hand, quadriplegia, oculomotor disturbance and bulbar palsy were observed in the poor outcome patients (mRS≥4; n=4). The critical features of a poor outcome were the age at onset (72.0±15.3 vs. 58.2±11.9 y.o.), inclusion of brainstem lesions and total occlusion of the basilar artery. In conclusion, older age at onset and/or basilar artery occlusion may be critical factors for predicting a poor outcome in bilateral thalamic infarction cases. (author)

  4. Aphasia following left thalamic hemorrhage

    International Nuclear Information System (INIS)

    Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro.

    1984-01-01

    We reported 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months), and described language disorders examined by Western Aphasia Battery (WAB) and measured cerebral blood flow by single photon emission CT. Examination of language by WAB revealed 4 aphasics out of 7 cases, and 3 patients had no language deficit. The patient with Wernicke's aphasia showed low density area only in the left posterior thalamus in X-ray CT, and revealed severe low blood flow area extending to left temporal lobe in emission CT. In the case with transcortical sensory aphasia, although X-ray CT showed no obvious low density area, emission CT revealed moderate low flow area in watershed area that involved the territory between posterior cerebral and middle cerebral arteries in the left temporooccipital region in addition to low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, whose score of repetition (8.4) was higher than that of comprehension (7.4), emission CT showed slight low flow area at the temporo-occipital region similarly as the case with transcortical sensory aphasia. In another case with anomic aphasia, scored 9 on both fluensy and comprehension subtests and 10 on repetition, there was wide low density area all over the left thalamus and midline shift to the right in X-ray CT, and emission CT showed severe low blood flow in the same region spreading widely toward the cerebral surface. On the other hand, in all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus. (J.P.N.)

  5. Thalamic changes with mesial temporal sclerosis: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Deasy, N.P.; Jarosz, J.M.; Cox, T.C.S. [Department of Neuroradiology, King' s College Hospital, London (United Kingdom); Elwes, R.C.D. [Department of Neurology, King' s College Hospital, London (United Kingdom); Polkey, C.E. [Department of Neurosurgery, King' s College and Maudsley Hospitals, London (United Kingdom)

    2000-05-01

    We reviewed the preoperative images of 28 patients with pathologically proven mesial temporal sclerosis, to assess thalamic asymmetry and signal change. A further 25 nonsurgical patients with temporal lobe epilepsy and unequivocal, unilateral changes of mesial temporal sclerosis, and 20 controls, were also reviewed. None of the control group had unequivocal asymmetry of the thalamus. There was an ipsilateral asymmetrically small thalamus in five (18 %) of the surgical group and in three (12 %) of the nonsurgical patients. In four cases there was thalamic signal change. In three patients with thalamic volume loss there was ipsilateral hemiatrophy. All patients with an asymmetrically small thalamus had an asymmetrically small fornix and all but one a small ipsilateral mamillary body. (orig.)

  6. Right thalamic infarction after closed head injury

    International Nuclear Information System (INIS)

    Nagaya, Takashi; Doi, Terushige; Katsumata, Tsuguo; Kuwayama, Naoto

    1986-01-01

    We reported a case of right thalamic infarction after a closed head injury. A 12-year-old boy was hit by an autotruck. He was semi-comatose, with left temporal scalp swelling and excoriation in the left lower limb. Three days after the accident, he exhibited left hemiparesis. CT scans on the day of the accident showed no abnormality, but on the following day, right thalamic infarction appeared. Right carotid angiography showed only an irregular vascular shadow in the cisternal segment of the right internal carotid artery. Vascular obstruction after closed head injury is rare, especially in the intracranial vessels, and several pathogeneses may be postulated. The right thalamic infarction in this case was supposed to be due to the damage of the perforators from the right posterior communicating artery and the right posterior cerebral artery, which were struck as a contre-coup by the force from the left side. (author)

  7. Dissociable Contributions of Thalamic Nuclei to Recognition Memory: Novel Evidence from a Case of Medial Dorsal Thalamic Damage

    Science.gov (United States)

    Newsome, Rachel N.; Trelle, Alexandra N.; Fidalgo, Celia; Hong, Bryan; Smith, Victoria M.; Jacob, Alexander; Ryan, Jennifer D.; Rosenbaum, R. Shayna; Cowell, Rosemary A.; Barense, Morgan D.

    2018-01-01

    The thalamic nuclei are thought to play a critical role in recognition memory. Specifically, the anterior thalamic nuclei and medial dorsal nuclei may serve as critical output structures in distinct hippocampal and perirhinal cortex systems, respectively. Existing evidence indicates that damage to the anterior thalamic nuclei leads to impairments…

  8. Language disturbances from mesencephalo-thalamic infarcts. Identification of thalamic nuclei by CT-reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarino, L G; Nicolai, A; Valassi, F [Ospedale Civile di Gorizia (Italy). Div. di Neurologia; Biasizzo, E [Ospedale di Udine (Italy). Servizio di Neuroradiologia

    1991-08-01

    The authors report the cases of two patients with CT-documented paramedian mesencephalo-thalamic infarcts, showing language disturbances. The first patient showed a non fluent, transcortical motor-like aphasia, the other had a fluent but severely paraphasic language disorder. The CT study disclosed that it was the dorso-median thalamic nucleus that was mostly involved in both cases. These findings agree with a few previous pathological studies suggesting that the paramedian thalamic nuclei, particlularly the dorso-median nucleus may play some role in language disturbances. However the anatomical basis for thalamic aphasia remains speculative, taking into account the importantce of cortical connections in the origin of subcortical neuropsychological disturbances. (orig.).

  9. Unilateral Thalamic Infarct Presenting as a Convulsive Seizure.

    Science.gov (United States)

    Kumar, Rajesh; Brohi, Hazim; Mughul, Afshan

    2017-09-01

    Lesions of the thalamus and those extending into midbrain can cause various types of movement disorders such as dystonia, asterixis and ballism-chorea. Seizures are rare manifestation of thalamic disorder. Occurrence of seizures in bilateral thalamic infarct has been reported; but seizures in unilateral thalamic infarct have been reported very rarely. Literature review showed only single case of perinatal unilateral thalamic infarct presenting with seizures. We are reporting a unique case of convulsive seizure at the onset of unilateral thalamic infarct in an adult male, which has never been reported to the best of our knowledge.

  10. Thalamic morphology in schizophrenia and schizoaffective disorder.

    Science.gov (United States)

    Smith, Matthew J; Wang, Lei; Cronenwett, Will; Mamah, Daniel; Barch, Deanna M; Csernansky, John G

    2011-03-01

    Biomarkers are needed that can distinguish between schizophrenia and schizoaffective disorder to inform the ongoing debate over the diagnostic boundary between these two disorders. Neuromorphometric abnormalities of the thalamus have been reported in individuals with schizophrenia and linked to core features of the disorder, but have not been similarly investigated in individuals with schizoaffective disorder. In this study, we examine whether individuals with schizoaffective disorder have a pattern of thalamic deformation that is similar or different to the pattern found in individuals with schizophrenia. T1-weighted magnetic resonance images were collected from individuals with schizophrenia (n = 47), individuals with schizoaffective disorder (n = 15), and controls (n = 42). Large-deformation, high-dimensional brain mapping was used to obtain three-dimensional surfaces of the thalamus. Multiple analyses of variance were used to test for group differences in volume and measures of surface shape. Individuals with schizophrenia or schizoaffective disorder have similar thalamic volumes. Thalamic surface shape deformation associated with schizophrenia suggests selective involvement of the anterior and posterior thalamus, while deformations in mediodorsal and ventrolateral regions were observed in both groups. Schizoaffective disorder had distinct deformations in medial and lateral thalamic regions. Abnormalities distinct to schizoaffective disorder suggest involvement of the central and ventroposterior medial thalamus which may be involved in mood circuitry, dorsolateral nucleus which is involved in recall processing, and the lateral geniculate nucleus which is involved in visual processing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. The relation between persistent coma and brain ischemia after severe brain injury.

    Science.gov (United States)

    Cheng, Quan; Jiang, Bing; Xi, Jian; Li, Zhen Yan; Liu, Jin Fang; Wang, Jun Yu

    2013-12-01

    To investigate the relation between brain ischemia and persistent vegetative state after severe traumatic brain injury. The 66 patients with severe brain injury were divided into two groups: The persistent coma group (coma duration ≥10 d) included 51 patients who had an admission Glasgow Coma Scale (GCS) of 5-8 and were unconscious for more than 10 d. There were 15 patients in the control group, their admission GCS was 5-8, and were unconscious for less than 10 d. The brain areas, including frontal, parietal, temporal, occipital lobes and thalamus, were measured by Single Photon Emission Computed Tomography (SPECT). In the first SPECT scan, multiple areas of cerebral ischemia were documented in all patients in both groups, whereas bilateral thalamic ischemia were presented in all patients in the persistent coma group and were absented in the control group. In the second SPECT scan taken during the period of analepsia, with an indication that unilateral thalamic ischemia were persisted in 28 of 41 patients in persistent coma group(28/41,68.29%). Persistent coma after severe brain injury is associated with bilateral thalamic ischemia.

  12. Thalamic neuron models encode stimulus information by burst-size modulation

    Directory of Open Access Journals (Sweden)

    Daniel Henry Elijah

    2015-09-01

    Full Text Available Thalamic neurons have been long assumed to fire in tonic mode during perceptive states, and in burst mode during sleep and unconsciousness. However, recent evidence suggests that bursts may also be relevant in the encoding of sensory information. Here we explore the neural code of such thalamic bursts. In order to assess whether the burst code is generic or whether it depends on the detailed properties of each bursting neuron, we analyzed two neuron models incorporating different levels of biological detail. One of the models contained no information of the biophysical processes entailed in spike generation, and described neuron activity at a phenomenological level. The second model represented the evolution of the individual ionic conductances involved in spiking and bursting, and required a large number of parameters. We analyzed the models' input selectivity using reverse correlation methods and information theory. We found that n-spike bursts from both models transmit information by modulating their spike count in response to changes to instantaneous input features, such as slope, phase, amplitude, etc. The stimulus feature that is most efficiently encoded by bursts, however, need not coincide with one of such classical features. We therefore searched for the optimal feature among all those that could be expressed as a linear transformation of the time-dependent input current. We found that bursting neurons transmitted 6 times more information about such more general features. The relevant events in the stimulus were located in a time window spanning ~100 ms before and ~20 ms after burst onset. Most importantly, the neural code employed by the simple and the biologically realistic models was largely the same, implying that the simple thalamic neuron model contains the essential ingredients that account for the computational properties of the thalamic burst code. Thus, our results suggest the n-spike burst code is a general property of

  13. Thalamic neuron models encode stimulus information by burst-size modulation.

    Science.gov (United States)

    Elijah, Daniel H; Samengo, Inés; Montemurro, Marcelo A

    2015-01-01

    Thalamic neurons have been long assumed to fire in tonic mode during perceptive states, and in burst mode during sleep and unconsciousness. However, recent evidence suggests that bursts may also be relevant in the encoding of sensory information. Here, we explore the neural code of such thalamic bursts. In order to assess whether the burst code is generic or whether it depends on the detailed properties of each bursting neuron, we analyzed two neuron models incorporating different levels of biological detail. One of the models contained no information of the biophysical processes entailed in spike generation, and described neuron activity at a phenomenological level. The second model represented the evolution of the individual ionic conductances involved in spiking and bursting, and required a large number of parameters. We analyzed the models' input selectivity using reverse correlation methods and information theory. We found that n-spike bursts from both models transmit information by modulating their spike count in response to changes to instantaneous input features, such as slope, phase, amplitude, etc. The stimulus feature that is most efficiently encoded by bursts, however, need not coincide with one of such classical features. We therefore searched for the optimal feature among all those that could be expressed as a linear transformation of the time-dependent input current. We found that bursting neurons transmitted 6 times more information about such more general features. The relevant events in the stimulus were located in a time window spanning ~100 ms before and ~20 ms after burst onset. Most importantly, the neural code employed by the simple and the biologically realistic models was largely the same, implying that the simple thalamic neuron model contains the essential ingredients that account for the computational properties of the thalamic burst code. Thus, our results suggest the n-spike burst code is a general property of thalamic neurons.

  14. Morphological Abnormalities of Thalamic Subnuclei in Migraine

    DEFF Research Database (Denmark)

    Magon, Stefano; May, Arne; Stankewitz, Anne

    2015-01-01

    UNLABELLED: The thalamus contains third-order relay neurons of the trigeminal system, and animal models as well as preliminary imaging studies in small cohorts of migraine patients have suggested a role of the thalamus in headache pathophysiology. However, larger studies using advanced imaging te...... is a disorder of the CNS in which not only is brain function abnormal, but also brain structure is undergoing significant remodeling....... a fully automated multiatlas approach. Deformation-based shape analysis was performed to localize surface abnormalities. Differences between patients with migraine and healthy subjects were assessed using an ANCOVA model. After correction for multiple comparisons, performed using the false discovery rate.......9) was observed in patients. This large-scale study indicates structural thalamic abnormalities in patients with migraine. The thalamic nuclei with abnormal volumes are densely connected to the limbic system. The data hence lend support to the view that higher-order integration systems are altered in migraine...

  15. Enlarged thalamic volumes and increased fractional anisotropy in the thalamic radiations in Veterans with suicide behaviors

    Directory of Open Access Journals (Sweden)

    Melissa eLopez-Larson

    2013-08-01

    Full Text Available Post-mortem studies have suggested a link between the thalamus, psychiatric disorders, and suicide. We evaluated the thalamus and anterior thalamic radiations (ATR in a group of Veterans with and without a history of suicidal behavior (SB to determine if thalamic abnormalities were associated with an increased risk of SB. Forty Veterans with mild traumatic brain injury (TBI and no SB (TBI-SB, 19 Veterans with mild TBI and a history of SB (TB+SB and 15 healthy controls (HC underwent MRI scanning including a structural and diffusion tensor imaging scan. Suicidal behaviors were evaluated utilizing the Columbia Suicide Rating Scale and impulsivity was measured using the Barratt Impulsiveness Scale (BIS. Differences in thalamic volumes and ATR fractional anisotropy (FA were examined between 1 TBI+SB versus HC and 2 TBI+SB versus combined HC and TBI-SB and 2 between TBI+SB and TBI-SB. Left and right thalamic volumes were significantly increased in those with TBI+SB compared to the HC, TBI-SB and the combined group. Veterans with TBI+SB had increased FA bilaterally compared to the HC, HC and TBI-SB group, and the TBI-SB only group. Significant positive associations were found for bilateral ATR and BIS in the TBI+SB group. Our findings of thalamic enlargement and increased FA in individuals with TBI+SB suggest that this region may be a biomarker for suicide risk. Our findings are consistent with previous evidence indicating that suicide may be associated with behavioral disinhibition and frontal-thalamic-limbic dysfunction and suggest a neurobiologic mechanism that may increase vulnerability to suicide.

  16. Neurological manifestations and PET studies of the thalamic vascular lesions

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Shinji; Kawamura, Mitsuru; Hirayama, Keizo [Chiba Univ. (Japan). School of Medicine

    1995-02-01

    We divided 38 patients with cerebrovascular disease of the thalamus into 5 groups according to the site of the thalamic lesions as confirmed by X-ray CT and/or MRI. In 16 patients, we examined the cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET). In the anteromedial thalamic lesion group, patients displayed disturbances of spontaneity, memory, reading and writing. CBF and CMRO{sub 2} were decreased in the frontal, parietal and temporal lobes on the side of the lesion. In the dorsolateral thalamic lesion group, ataxic hemiparesis was a characteristic symptom. CBF and CMRO{sub 2} were decreased in frontoparietal lobes on the side of the lesion. In the group with lesions confined to the nucleus ventralis posterioris thalami, the main symptoms were sensory disturbance, with cheiro-oral sensory syndrome being particularly evident. CBF and CMRO{sub 2} were decreased in the parietal lobe on the side of the lesion. In the group with posterolateral thalamic lesions without pulvinar involvement, patients exhibited thalamic syndrome without thalamic pain. CBF and CMRO{sub 2} were decreased in the frontoparietal and temporal lobes on the side of the lesion. In contrast, in the group with posterolateral thalamic lesions with pulvinar involvement, all patients showed thalamic pain. The decrease in CBF and CMRO{sub 2} extended to the inferomedial region of the temporal lobe in addition to the area of decreased CBF and CMRO{sub 2} observed in the group with posterolateral thalamic lesions without pulvinar involvement. Based on these results, we speculate that the neurological manifestations of thalamic vascular disease are associated with a decrease in cortical CBF and CMRO{sub 2} secondary to the thalamic lesions. (author).

  17. Neurological manifestations and PET studies of the thalamic vascular lesions

    International Nuclear Information System (INIS)

    Matsuda, Shinji; Kawamura, Mitsuru; Hirayama, Keizo

    1995-01-01

    We divided 38 patients with cerebrovascular disease of the thalamus into 5 groups according to the site of the thalamic lesions as confirmed by X-ray CT and/or MRI. In 16 patients, we examined the cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO 2 ) by positron emission tomography (PET). In the anteromedial thalamic lesion group, patients displayed disturbances of spontaneity, memory, reading and writing. CBF and CMRO 2 were decreased in the frontal, parietal and temporal lobes on the side of the lesion. In the dorsolateral thalamic lesion group, ataxic hemiparesis was a characteristic symptom. CBF and CMRO 2 were decreased in frontoparietal lobes on the side of the lesion. In the group with lesions confined to the nucleus ventralis posterioris thalami, the main symptoms were sensory disturbance, with cheiro-oral sensory syndrome being particularly evident. CBF and CMRO 2 were decreased in the parietal lobe on the side of the lesion. In the group with posterolateral thalamic lesions without pulvinar involvement, patients exhibited thalamic syndrome without thalamic pain. CBF and CMRO 2 were decreased in the frontoparietal and temporal lobes on the side of the lesion. In contrast, in the group with posterolateral thalamic lesions with pulvinar involvement, all patients showed thalamic pain. The decrease in CBF and CMRO 2 extended to the inferomedial region of the temporal lobe in addition to the area of decreased CBF and CMRO 2 observed in the group with posterolateral thalamic lesions without pulvinar involvement. Based on these results, we speculate that the neurological manifestations of thalamic vascular disease are associated with a decrease in cortical CBF and CMRO 2 secondary to the thalamic lesions. (author)

  18. [Thalamic Stroke and Associated Behavior Disorders. Possibilities for Integral Management: Case Report].

    Science.gov (United States)

    Camargo, Loida Camargo; Sánchez, Katherine Parra

    2012-06-01

    Since ancient Greece, cerebrovascular accidents have been described with no variation. Even today, they are still a catastrophic event in the lives of patients with a high risk of disabling sequelae. Case report of a 56-year male patient with thalamic ischemia. The intervention with integral strategies involving pharmacological management and cognitive interventions was decisive for the satisfactory evolution of the patient. The management of patients with cerebrovascular accidents cannot be limited to the emergency room. Pharmacological advances in programs and cognitive intervention methods provide intervention tools from the very beginning of the stroke thus reducing the impact of long-term sequelae, and consequently enabling a better reintegration of the patient to his family. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  19. Thalamic hemorrhage following carotid angioplasty and stenting

    International Nuclear Information System (INIS)

    Friedman, Jonathan A.; Kallmes, David F.; Wijdicks, Eelco F.M.

    2004-01-01

    Carotid angioplasty and stenting (CAS) has emerged as an alternative treatment of carotid stenosis for patients poorly suited for endarterectomy. Intracerebral hemorrhage following carotid revascularization is rare and thought to be related to hyperperfusion injury in most cases. Early experience suggests an increased incidence of hemorrhage following CAS as compared to endarterectomy. We describe a patient who suffered a thalamic hemorrhage following CAS. Because this hemorrhage occurred in a vascular territory unlikely to have been supplied by the treated artery, this case suggests that the mechanism of intracerebral hemorrhage following CAS may in some cases be different from the hyperperfusion hemorrhage classically described following endarterectomy. (orig.)

  20. A distinct boundary between the higher brain's susceptibility to ischemia and the lower brain's resistance.

    Directory of Open Access Journals (Sweden)

    C Devin Brisson

    Full Text Available Higher brain regions are more susceptible to global ischemia than the brainstem, but is there a gradual increase in vulnerability in the caudal-rostral direction or is there a discrete boundary? We examined the interface between `higher` thalamus and the hypothalamus the using live brain slices where variation in blood flow is not a factor. Whole-cell current clamp recording of 18 thalamic neurons in response to 10 min O2/glucose deprivation (OGD revealed a rapid anoxic depolarization (AD from which thalamic neurons do not recover. Newly acquired neurons could not be patched following AD, confirming significant regional thalamic injury. Coinciding with AD, light transmittance (LT imaging during whole-cell recording showed an elevated LT front that initiated in midline thalamus and that propagated into adjacent hypothalamus. However, hypothalamic neurons patched in paraventricular nucleus (PVN, n= 8 magnocellular and 12 parvocellular neurons and suprachiasmatic nucleus (SCN, n= 18 only slowly depolarized as AD passed through these regions. And with return to control aCSF, hypothalamic neurons repolarized and recovered their input resistance and action potential amplitude. Moreover, newly acquired hypothalamic neurons could be readily patched following exposure to OGD, with resting parameters similar to neurons not previously exposed to OGD. Thalamic susceptibility and hypothalamic resilience were also observed following ouabain exposure which blocks the Na(+/K(+ pump, evoking depolarization similar to OGD in all neuronal types tested. Finally, brief exposure to elevated [K(+]o caused spreading depression (SD, a milder, AD-like event only in thalamic neurons so SD generation is regionally correlated with strong AD. Therefore the thalamus-hypothalamus interface represents a discrete boundary where neuronal vulnerability to ischemia is high in thalamus (like more rostral neocortex, striatum, hippocampus. In contrast hypothalamic neurons are

  1. Generation of thalamic neurons from mouse embryonic stem cells.

    Science.gov (United States)

    Shiraishi, Atsushi; Muguruma, Keiko; Sasai, Yoshiki

    2017-04-01

    The thalamus is a diencephalic structure that plays crucial roles in relaying and modulating sensory and motor information to the neocortex. The thalamus develops in the dorsal part of the neural tube at the level of the caudal forebrain. However, the molecular mechanisms that are essential for thalamic differentiation are still unknown. Here, we have succeeded in generating thalamic neurons from mouse embryonic stem cells (mESCs) by modifying the default method that induces the most-anterior neural type in self-organizing culture. A low concentration of the caudalizing factor insulin and a MAPK/ERK kinase inhibitor enhanced the expression of the caudal forebrain markers Otx2 and Pax6. BMP7 promoted an increase in thalamic precursors such as Tcf7l2 + /Gbx2 + and Tcf7l2 + /Olig3 + cells. mESC thalamic precursors began to express the glutamate transporter vGlut2 and the axon-specific marker VGF, similar to mature projection neurons. The mESC thalamic neurons extended their axons to cortical layers in both organotypic culture and subcortical transplantation. Thus, we have identified the minimum elements sufficient for in vitro generation of thalamic neurons. These findings expand our knowledge of thalamic development. © 2017. Published by The Company of Biologists Ltd.

  2. Fatal thalamic abscess secondary to dental infection.

    Science.gov (United States)

    Basyuni, Shadi; Sharma, Valmiki; Santhanam, Vijay; Ferro, Ashley

    2015-12-17

    We present the case of poor neurological recovery and subsequent death secondary to a thalamic abscess in a 53-year-old man. This patient initially presented with sudden dysarthria and left hemiparesis while driving. Neuroimaging showed a multilobular abscess involving the right thalamus with oedema extending to the basal ganglionic region and brainstem. The source of the abscess was initially unknown and it required draining multiple times while the different causes were being explored. The patient's neurological state along with intubation made for a difficult and inconclusive oral examination. It was only after neuroimaging included tooth-bearing areas that it became evident that this patient had extensive periodontal disease with multiple areas of periapical radiolucencies. The patient underwent complete dental clearance alongside repeated drainage of the abscess. Despite initial postoperative improvement, the patient never recovered from the neurological damage and died 3 weeks later. 2015 BMJ Publishing Group Ltd.

  3. Isolated thalamic tuberculoma presenting as ataxic hemiparesis

    Science.gov (United States)

    Sahu, Ritesh; Patil, Tushar B; Kori, Prakash; Shukla, Rakesh

    2013-01-01

    Lacunar syndrome is a neurodeficit secondary to a deep cerebral lesion, usually because of microatheroma of small arteries. Ataxic hemiparesis (AH) is a lacunar syndrome with unilateral pyramidal weakness and ipsilateral ataxia. Thalamic tuberculoma, as a cause of AH, has not been previously described in the literature. We describe an elderly man who presented with left hemiparesis and ipsilateral ataxia. Clinical examination revealed upper motor neuron left facial paresis and left-sided hemiparesis. The patient had incoordination in left upper and lower limbs. Mantoux test was positive and erythrocyte sedimentation rate was elevated. MRI of brain showed a conglomerated hypointense lesion in the right thalamus with a peripheral hyperintensity on T1-weighted imaging and a hyperintense lesion in T2-weighted imaging with significant perilesional oedema, suggesting a tuberculoma. The patient was treated with antitubercular therapy and was symptomatically better at the 9 months follow-up. PMID:23580686

  4. CT classification of small thalamic hemorrhages

    International Nuclear Information System (INIS)

    Kawahara, Nobutaka; Kaneko, Mitsuo; Tanaka, Keisei; Muraki, Masaaki; Sato, Kengo

    1984-01-01

    The thalamus is located deep in the cerebral hemispheres, and most of its nuclei have reciprocal fiber connections with specific areas over the cerebral cortex. Localized lesions in the thalamus, therefore, can cause specific neurological deficits, depending on their locations. From this point of view, we reviewed 110 cases, admitted over the past 7 years, with thalamic hemorrhages 37 (34%) of which were small hematomas less than 2 cm in diameter. These small hematomas could be divided into 4 types depending on their locations as follows: antero-lateral type, postero-lateral type, medial type, and dorsal type. Each type had the peculiar clinical features described below: 1) Postero-lateral Type (PL type, 28 cases, 76%): The original symptom was a sudden onset of moderate to severe sensori-motor deficits in most cases. The patients were mostly alert or only slightly confused. 2) Antero-lateral Type (AL type, 4 cases, 11%): The patients of this type first presented with sensori-motor disturbance and prefrontal signs. Both were generally mild and often disappeared early. 3) Medial Type (M type, 3 cases, 8%): The main symptom at onset was either a disturbance of consciousness or dementia. 4) Dorsal Type (D type, 2 cases, 5%): One patient with a right thalamic hematoma of this type showed geographical agnosia and visuo-constructive apraxia. The other patient, with a left-sided hematoma, exhibited transient clumsiness of the right hand and mild dysphasia. In our experience, the above classification of small hematomas clearly delineated the clinical symptoms and neurological signs of the different types; therefore, the symptoms and signs in larger hematoma could be explained by a combination of those of each type. (J.P.N.)

  5. Thalamic gap junctions control local neuronal synchrony and influence macroscopic oscillation amplitude during EEG alpha rhythms

    Directory of Open Access Journals (Sweden)

    Stuart eHughes

    2011-08-01

    Full Text Available Although EEG alpha ( (8-13 Hz rhythms are often considered to reflect an ‘idling’ brain state, numerous studies indicate that they are also related to many aspects of perception. Recently, we outlined a potential cellular substrate by which such aspects of perception might be linked to basic  rhythm mechanisms. This scheme relies on a specialized subset of rhythmically bursting thalamocortical (TC neurons (high-threshold bursting cells in the lateral geniculate nucleus (LGN which are interconnected by gap junctions (GJs. By engaging GABAergic interneurons, that in turn inhibit conventional relay-mode TC neurons, these cells can lead to an effective temporal framing of thalamic relay-mode output. Although the role of GJs is pivotal in this scheme, evidence for their involvement in thalamic  rhythms has thus far mainly derived from experiments in in vitro slice preparations. In addition, direct anatomical evidence of neuronal GJs in the LGN is currently lacking. To address the first of these issues we tested the effects of the GJ inhibitors, carbenoxolone (CBX and 18-glycyrrhetinic acid (18-GA, given directly to the LGN via reverse microdialysis, on spontaneous LGN and EEG  rhythms in behaving cats. We also examined the effect of CBX on  rhythm-related LGN unit activity. Indicative of a role for thalamic GJs in these activities, 18-GA and CBX reversibly suppressed both LGN and EEG  rhythms, with CBX also decreasing neuronal synchrony. To address the second point, we used electron microscopy to obtain definitive ultrastructural evidence for the presence of GJs between neurons in the cat LGN. As interneurons show no phenotypic evidence of GJ coupling (i.e. dye-coupling and spikelets we conclude that these GJs must belong to TC neurons. The potential significance of these findings for relating macroscopic changes in  rhythms to basic cellular processes is discussed.

  6. MRI of paramedian thalamic stroke with sleep disturbance

    International Nuclear Information System (INIS)

    Loevblad, K.O.; Bassetti, C.; Mathis, J.; Schroth, G.

    1997-01-01

    The paramedian thalamus is believed to play an important role in the regulation of sleep, and disturbances of sleep regulation are known to occur in paramedian thalamic stroke (PTS). We examined 12 consecutive patients with PTS and sleep disturbance by MRI. Two distinct groups of patients could be defined: six presenting with severe hypersomnia (group 1) and six with slight sleepiness (group 2). On MRI, all patients had ischaemic lesions involving the paramedian thalamic nuclei, the centre of the lesions being the dorsomedial and centromedial thalamic nuclei. In group 1 the lesions were bilateral, butterfly-shaped infarcts involving the paramedian nuclei (three cases), or unilateral with an extension into the subthalamic nuclei. In group 2 the lesions were unilateral and limited to the paramedian nuclei, mainly the dorsomedial nucleus. Bilateral lesions can be attributed to a common origin in some cases for both paramedian thalamic arteries and the mesencephalic arteries. (orig.). With 5 figs

  7. Severity of exercise-induced ischemia with chest pain and recovery from ischemia after the disappearance of chest pain

    International Nuclear Information System (INIS)

    Akutsu, Yasushi; Shinozuka, Akira; Kodama, Yusuke; Li, Hui-Ling; Yamanaka, Hideyuki; Katagiri, Takashi

    2004-01-01

    The severity of exercise-induced painful ischemia and its recovery after the disappearance of pain are unknown. The aim of this study was to investigate the difference in severity of ischemia at both exercise and postexercise between painful ischemia and painless ischemia. After injections of technetium-99m tetrofosmin at peak ergometer exercise and thallium-201 at 3 minutes postexercise, dual-isotope single photon emission tomography was performed in 78 patients with angiographically proven ischemic heart disease. The extent of ischemic areas (the number of areas), the depth of ischemia in the ischemic area (the severity score of ischemia) and the extension of ischemia toward long axis of the left ventricle (the number of left ventricular levels with ischemic areas in apical, middle, and basal levels) at both exercise and postexercise were compared on the basis of the presence of pain and a history of diabetes mellitus (DM). The symptoms improved within 3 minutes postexercise in all painful ischemia patients. Of 59 patients with reversible ischemia, except for 4 painful ischemia patients with DM, the extent and depth of ischemia at postexercise were more severe in 14 painful ischemia patients without DM and 13 painless ischemia patients with DM than 28 painless ischemia patients without DM (extent; 2.9±1.7 areas, 3.5±2.8 areas versus 1.4±1.8 areas, P=0.005, depth; 3.8±3.1 scores, 5.8±5.4 scores versus 1.9±3.0 scores, P=0.0084, respectively) despite a comparable severity of ischemia at peak exercise (extent; 5.4±2.6 areas, 6.0±2.4 areas versus 4.3±3.3 areas, depth; 9.3±5.7 scores, 10.7±7.3 scores and 7.5±8.1 scores, all NS). The extension of ischemia toward long-axis of the left ventricle at both peak exercise and postexercise was more severe in the former 2 groups than the latter group (peak exercise; 2.4±0.6 levels, 2.5±0.7 levels versus 1.9 ±0.8 levels, P=0.0263, postexercise: 1.8±0.7 levels, 1.5±0.9 levels versus 0.8±0.8 levels, P=0

  8. Global suppression of electrocortical activity in unilateral perinatal thalamic stroke.

    LENUS (Irish Health Repository)

    Kharoshankaya, Liudmila

    2014-07-01

    We present an unusual case of persistent generalized electroencephalography (EEG) suppression and right-sided clonic seizures in a male infant born at 40(+2) weeks\\' gestation, birthweight 3240g, with an isolated unilateral thalamic stroke. The EEG at 13 hours after birth showed a generalized very low amplitude background pattern, which progressed to frequent electrographic seizures over the left hemisphere. The interictal background EEG pattern remained grossly abnormal over the next 48 hours, showing very low background amplitudes (<10μV). Magnetic resonance imaging revealed an isolated acute left-sided thalamic infarction. This is the first description of severe global EEG suppression caused by an isolated unilateral thalamic stroke and supports the role of the thalamus as the control centre for cortical electrical activity.

  9. Response sensitivity of barrel neuron subpopulations to simulated thalamic input.

    Science.gov (United States)

    Pesavento, Michael J; Rittenhouse, Cynthia D; Pinto, David J

    2010-06-01

    Our goal is to examine the relationship between neuron- and network-level processing in the context of a well-studied cortical function, the processing of thalamic input by whisker-barrel circuits in rodent neocortex. Here we focus on neuron-level processing and investigate the responses of excitatory and inhibitory barrel neurons to simulated thalamic inputs applied using the dynamic clamp method in brain slices. Simulated inputs are modeled after real thalamic inputs recorded in vivo in response to brief whisker deflections. Our results suggest that inhibitory neurons require more input to reach firing threshold, but then fire earlier, with less variability, and respond to a broader range of inputs than do excitatory neurons. Differences in the responses of barrel neuron subtypes depend on their intrinsic membrane properties. Neurons with a low input resistance require more input to reach threshold but then fire earlier than neurons with a higher input resistance, regardless of the neuron's classification. Our results also suggest that the response properties of excitatory versus inhibitory barrel neurons are consistent with the response sensitivities of the ensemble barrel network. The short response latency of inhibitory neurons may serve to suppress ensemble barrel responses to asynchronous thalamic input. Correspondingly, whereas neurons acting as part of the barrel circuit in vivo are highly selective for temporally correlated thalamic input, excitatory barrel neurons acting alone in vitro are less so. These data suggest that network-level processing of thalamic input in barrel cortex depends on neuron-level processing of the same input by excitatory and inhibitory barrel neurons.

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  18. Global brain ischemia and reperfusion.

    Science.gov (United States)

    White, B C; Grossman, L I; O'Neil, B J; DeGracia, D J; Neumar, R W; Rafols, J A; Krause, G S

    1996-05-01

    Brain damage accompanying cardiac arrest and resuscitation is frequent and devastating. Neurons in the hippocampus CA1 and CA4 zones and cortical layers III and V are selectively vulnerable to death after injury by ischemia and reperfusion. Ultrastructural evidence indicates that most of the structural damage is associated with reperfusion, during which the vulnerable neurons develop disaggregation of polyribosomes, peroxidative damage to unsaturated fatty acids in the plasma membrane, and prominent alterations in the structure of the Golgi apparatus that is responsible for membrane assembly. Reperfusion is also associated with vulnerable neurons with prominent production of messenger RNAs for stress proteins and for the proteins of the activator protein-1 complex, but these vulnerable neurons fail to efficiently translate these messages into the proteins. The inhibition of protein synthesis during reperfusion involves alteration of translation initiation factors, specifically serine phosphorylation of the alpha-subunit of eukaryotic initiation factor-2 (elF-2 alpha). Growth factors--in particular, insulin--have the potential to reverse phosphorylation of elF-2 alpha, promote effective translation of the mRNA transcripts generated in response to ischemia and reperfusion, enhance neuronal defenses against radicals, and stimulate lipid synthesis and membrane repair. There is now substantial evidence that the insulin-class growth factors have neuron-sparing effects against damage by radicals and ischemia and reperfusion. This new knowledge may provide a fundamental basis for a rational approach to "cerebral resuscitation" that will allow substantial amelioration of the often dismal neurologic outcome now associated with resuscitation from cardiac arrest.

  19. Connectivity derived thalamic segmentation in deep brain stimulation for tremor

    Directory of Open Access Journals (Sweden)

    Harith Akram

    Full Text Available The ventral intermediate nucleus (VIM of the thalamus is an established surgical target for stereotactic ablation and deep brain stimulation (DBS in the treatment of tremor in Parkinson's disease (PD and essential tremor (ET. It is centrally placed on a cerebello-thalamo-cortical network connecting the primary motor cortex, to the dentate nucleus of the contralateral cerebellum through the dentato-rubro-thalamic tract (DRT. The VIM is not readily visible on conventional MR imaging, so identifying the surgical target traditionally involved indirect targeting that relies on atlas-defined coordinates. Unfortunately, this approach does not fully account for individual variability and requires surgery to be performed with the patient awake to allow for intraoperative targeting confirmation. The aim of this study is to identify the VIM and the DRT using probabilistic tractography in patients that will undergo thalamic DBS for tremor. Four male patients with tremor dominant PD and five patients (three female with ET underwent high angular resolution diffusion imaging (HARDI (128 diffusion directions, 1.5 mm isotropic voxels and b value = 1500 preoperatively. Patients received VIM-DBS using an MR image guided and MR image verified approach with indirect targeting. Postoperatively, using parallel Graphical Processing Unit (GPU processing, thalamic areas with the highest diffusion connectivity to the primary motor area (M1, supplementary motor area (SMA, primary sensory area (S1 and contralateral dentate nucleus were identified. Additionally, volume of tissue activation (VTA corresponding to active DBS contacts were modelled. Response to treatment was defined as 40% reduction in the total Fahn-Tolosa-Martin Tremor Rating Score (FTMTRS with DBS-ON, one year from surgery. Three out of nine patients had a suboptimal, long-term response to treatment. The segmented thalamic areas corresponded well to anatomically known counterparts in the ventrolateral

  20. Communication skills and thalamic lesion: Strategies of rehabilitation.

    Science.gov (United States)

    Amaddii, Luisa; Centorrino, Santi; Cambi, Jacopo; Passali, Desiderio

    2014-01-01

    To describe the speech rehabilitation history of patients with thalamic lesions. Thalamic lesions can affect speech and language according to diverse thalamic nuclei involved. Because of the strategic functional position of the thalamus within the cognitive networks, its lesion can also interfere with other cognitive processes, such as attention, memory and executive functions. Alterations of these cognitive domains contribute significantly to language deficits, leading to communicative inefficacy. This fact must be considered in the rehabilitation efforts. Whereas evaluation of cognitive functions and communicative efficiency is different from that of aphasic disorder, treatment should also be different. The treatment must be focused on specific cognitive deficits with belief in the regaining of communicative ability, as well as it occurs in therapy of pragmatic disorder in traumatic brain injury: attention process training, mnemotechnics and prospective memory training. According to our experience: (a) there is a close correlation between cognitive processes and communication skills; (b) alterations of attention, memory and executive functions cause a loss of efficiency in the language use; and (c) appropriate cognitive treatment improves pragmatic competence and therefore the linguistic disorder. For planning a speech-therapy it is important to consider the relationship between cognitive functions and communication. The cognitive/behavioral treatment confirms its therapeutic efficiency for thalamic lesions. Copyright © 2014 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  1. Hypertensive thalamic hemorrhage. Clinical symptoms and outcomes in 40 cases

    Energy Technology Data Exchange (ETDEWEB)

    Munaka, Masahiro; Nishikawa, Michio; Hirai, Osamu; Kaneko, Takaaki; Watanabe, Syu; Fukuma, Jun; Handa, Hajime

    1988-12-01

    In the past six years, we have had experience with 40 patients with hypertensive thalamic hemorrhages, as verified by CT scan at our hospital within 24 hours. These patients were classified into the following three groups according to the location of the bleeding point and the size of the hematoma: (1) anteromedial (4 cases), (2) posterolateral (16 cases), and (3) massive (20 cases). The (1) and (2) hematomas were small (less than 3 cm in diameter), while those in (3) were large (more than 3 cm in diameter). Twenty cases (50% of all the thalamic hematomas) were small hematomas. The characteristic clinical symptoms of the anteromedial type were a mild disturbance of consciousness and thalamic dementia, while those of the posterolateral type were motor and sensory disturbance, and thalamic aphasia, respectively. Twenty cases (50%) were large hematomas. The clinical symptoms of these cases were mainly consciousness disturbance; 7 of them expired. Based on this experience, it may be considered that the patients whose hematoma size was larger than 3 cm had a poor prognosis and that the patients with the posterolateral type had a poor functional diagnosis.

  2. Thalamic control of sensory selection in divided attention.

    Science.gov (United States)

    Wimmer, Ralf D; Schmitt, L Ian; Davidson, Thomas J; Nakajima, Miho; Deisseroth, Karl; Halassa, Michael M

    2015-10-29

    How the brain selects appropriate sensory inputs and suppresses distractors is unknown. Given the well-established role of the prefrontal cortex (PFC) in executive function, its interactions with sensory cortical areas during attention have been hypothesized to control sensory selection. To test this idea and, more generally, dissect the circuits underlying sensory selection, we developed a cross-modal divided-attention task in mice that allowed genetic access to this cognitive process. By optogenetically perturbing PFC function in a temporally precise window, the ability of mice to select appropriately between conflicting visual and auditory stimuli was diminished. Equivalent sensory thalamocortical manipulations showed that behaviour was causally dependent on PFC interactions with the sensory thalamus, not sensory cortex. Consistent with this notion, we found neurons of the visual thalamic reticular nucleus (visTRN) to exhibit PFC-dependent changes in firing rate predictive of the modality selected. visTRN activity was causal to performance as confirmed by bidirectional optogenetic manipulations of this subnetwork. Using a combination of electrophysiology and intracellular chloride photometry, we demonstrated that visTRN dynamically controls visual thalamic gain through feedforward inhibition. Our experiments introduce a new subcortical model of sensory selection, in which the PFC biases thalamic reticular subnetworks to control thalamic sensory gain, selecting appropriate inputs for further processing.

  3. Outcome After Pituitary Radiosurgery for Thalamic Pain Syndrome

    International Nuclear Information System (INIS)

    Hayashi, Motohiro; Chernov, Mikhail F.; Taira, Takaomi; Ochiai, Taku; Nakaya, Kotaro; Tamura, Noriko; Goto, Shinichi; Yomo, Shoji; Kouyama, Nobuo; Katayama, Yoko; Kawakami, Yoriko; Izawa, Masahiro; Muragaki, Yoshihiro

    2007-01-01

    Purpose: To evaluate outcomes after pituitary radiosurgery in patients with post-stroke thalamic pain syndrome. Methods and Materials: From 2002 to 2006, 24 patients with thalamic pain syndrome underwent pituitary radiosurgery at Tokyo Women's Medical University and were followed at least 12 months thereafter. The radiosurgical target was defined as the pituitary gland and its connection with the pituitary stalk. The maximum dose varied from 140 to 180 Gy. Mean follow-up after treatment was 35 months (range, 12-48 months). Results: Initial pain reduction, usually within 48 h after radiosurgery, was marked in 17 patients (71%). However, in the majority of cases the pain recurred within 6 months after treatment, and at the time of the last follow-up examination durable pain control was marked in only 5 patients (21%). Ten patients (42%) had treatment-associated side effects. Anterior pituitary abnormalities were marked in 8 cases and required hormonal replacement therapy in 3; transient diabetes insipidus was observed in 2 cases, transient hyponatremia in 1, and clinical deterioration due to increase of the numbness severity despite significant reduction of pain was seen once. Conclusions: Pituitary radiosurgery for thalamic pain results in a high rate of initial efficacy and is accompanied by acceptable morbidity. It can be used as a primary minimally invasive management option for patients with post-stroke thalamic pain resistant to medical therapy. However, in the majority of cases pain recurrence occurs within 1 year after treatment

  4. Neuroanatomical considerations of isolated hearing loss in thalamic hemorrhage

    Directory of Open Access Journals (Sweden)

    Nitin Agarwal, M.D.

    2016-12-01

    Conclusion: Presumably, this neurological deficit was caused by a hypertensive hemorrhage in the posterior right thalamus. The following case and discussion will review the potential neuroanatomical pathways that we suggest could make isolated hearing loss be part of a “thalamic syndrome.”

  5. Lateral and Anterior Thalamic Lesions Impair Independent Memory Systems

    Science.gov (United States)

    Mitchell, Anna S.; Dalrymple-Alford, John C.

    2006-01-01

    Damage to the medial region of the thalamus, both in clinical cases (e.g., patients with infarcts or the Korsakoff's syndrome) and animal lesion models, is associated with variable amnesic deficits. Some studies suggest that many of these memory deficits rely on the presence of lateral thalamic lesions (LT) that include the intralaminar nuclei,…

  6. Visual Orientation and Directional Selectivity through Thalamic Synchrony

    Science.gov (United States)

    Stanley, Garrett B.; Jin, Jianzhong; Wang, Yushi; Desbordes, Gaëlle; Wang, Qi; Black, Michael J.; Alonso, Jose-Manuel

    2012-01-01

    Thalamic neurons respond to visual scenes by generating synchronous spike trains on the timescale of 10 – 20 ms that are very effective at driving cortical targets. Here we demonstrate that this synchronous activity contains unexpectedly rich information about fundamental properties of visual stimuli. We report that the occurrence of synchronous firing of cat thalamic cells with highly overlapping receptive fields is strongly sensitive to the orientation and the direction of motion of the visual stimulus. We show that this stimulus selectivity is robust, remaining relatively unchanged under different contrasts and temporal frequencies (stimulus velocities). A computational analysis based on an integrate-and-fire model of the direct thalamic input to a layer 4 cortical cell reveals a strong correlation between the degree of thalamic synchrony and the nonlinear relationship between cortical membrane potential and the resultant firing rate. Together, these findings suggest a novel population code in the synchronous firing of neurons in the early visual pathway that could serve as the substrate for establishing cortical representations of the visual scene. PMID:22745507

  7. Disrupted thalamic prefrontal pathways in patients with idiopathic dystonia

    NARCIS (Netherlands)

    Bonilha, Leonardo; de Vries, Paulien M.; Hurd, Mark W.; Rorden, Chris; Morgan, Paul S.; Besenski, Nada; Bergmann, Kenneth J.; Hinson, Vanessa K.

    There are quantifiable abnormalities in water diffusion properties of the white matter in thalamic and prefrontal areas in patients with idiopathic dystonia (ID). However, it is unclear which pathways are disrupted in these patients. Using probabilistic tractography of high resolution DTI, we

  8. Sleep onset uncovers thalamic abnormalities in patients with idiopathic generalised epilepsy

    Directory of Open Access Journals (Sweden)

    Andrew P. Bagshaw

    Full Text Available The thalamus is crucial for sleep regulation and the pathophysiology of idiopathic generalised epilepsy (IGE, and may serve as the underlying basis for the links between the two. We investigated this using EEG-fMRI and a specific emphasis on the role and functional connectivity (FC of the thalamus. We defined three types of thalamic FC: thalamocortical, inter-hemispheric thalamic, and intra-hemispheric thalamic. Patients and controls differed in all three measures, and during wakefulness and sleep, indicating disorder-dependent and state-dependent modification of thalamic FC. Inter-hemispheric thalamic FC differed between patients and controls in somatosensory regions during wakefulness, and occipital regions during sleep. Intra-hemispheric thalamic FC was significantly higher in patients than controls following sleep onset, and disorder-dependent alterations to FC were seen in several thalamic regions always involving somatomotor and occipital regions. As interactions between thalamic sub-regions are indirect and mediated by the inhibitory thalamic reticular nucleus (TRN, the results suggest abnormal TRN function in patients with IGE, with a regional distribution which could suggest a link with the thalamocortical networks involved in the generation of alpha rhythms. Intra-thalamic FC could be a more widely applicable marker beyond patients with IGE. Keywords: Functional connectivity, Generalised epilepsy, Sleep, Thalamic reticular nucleus thalamus

  9. Connectivity derived thalamic segmentation in deep brain stimulation for tremor.

    Science.gov (United States)

    Akram, Harith; Dayal, Viswas; Mahlknecht, Philipp; Georgiev, Dejan; Hyam, Jonathan; Foltynie, Thomas; Limousin, Patricia; De Vita, Enrico; Jahanshahi, Marjan; Ashburner, John; Behrens, Tim; Hariz, Marwan; Zrinzo, Ludvic

    2018-01-01

    The ventral intermediate nucleus (VIM) of the thalamus is an established surgical target for stereotactic ablation and deep brain stimulation (DBS) in the treatment of tremor in Parkinson's disease (PD) and essential tremor (ET). It is centrally placed on a cerebello-thalamo-cortical network connecting the primary motor cortex, to the dentate nucleus of the contralateral cerebellum through the dentato-rubro-thalamic tract (DRT). The VIM is not readily visible on conventional MR imaging, so identifying the surgical target traditionally involved indirect targeting that relies on atlas-defined coordinates. Unfortunately, this approach does not fully account for individual variability and requires surgery to be performed with the patient awake to allow for intraoperative targeting confirmation. The aim of this study is to identify the VIM and the DRT using probabilistic tractography in patients that will undergo thalamic DBS for tremor. Four male patients with tremor dominant PD and five patients (three female) with ET underwent high angular resolution diffusion imaging (HARDI) (128 diffusion directions, 1.5 mm isotropic voxels and b value = 1500) preoperatively. Patients received VIM-DBS using an MR image guided and MR image verified approach with indirect targeting. Postoperatively, using parallel Graphical Processing Unit (GPU) processing, thalamic areas with the highest diffusion connectivity to the primary motor area (M1), supplementary motor area (SMA), primary sensory area (S1) and contralateral dentate nucleus were identified. Additionally, volume of tissue activation (VTA) corresponding to active DBS contacts were modelled. Response to treatment was defined as 40% reduction in the total Fahn-Tolosa-Martin Tremor Rating Score (FTMTRS) with DBS-ON, one year from surgery. Three out of nine patients had a suboptimal, long-term response to treatment. The segmented thalamic areas corresponded well to anatomically known counterparts in the ventrolateral (VL

  10. Pathophysiology of brain ischemia as it relates to the therapy of acute ischemic stroke

    DEFF Research Database (Denmark)

    Lassen, N A

    1990-01-01

    Current knowledge of the pathophysiology of cerebral ischemia, summarized in the present study, predicts that neurological deficits caused by moderate ischemia (flows in the penumbral range between 23 and 10 ml/100 g/min) are reversible provided flow is restored within 3-4 h of onset. It also...

  11. Remote effect in patients with thalamic stroke. A study using positron emission tomography

    International Nuclear Information System (INIS)

    Komaba, Yuichi; Kitamura, Shin; Terashi, Akiro

    1998-01-01

    The purpose of this study was to investigate the functional relation between the thalamus and other cortical regions in patients with thalamic stroke from the view of cerebral blood flow (CBF) and the cerebral metabolic rate of oxygen (CMRO 2 ) using positron emission tomography (PET). Twenty patients with thalamic stroke (right lesion=8, left lesion=12) and 7 normal controls were studied. Five patients were diagnosed as having thalamic infarction, and 15 (patients were diagnosed) as having thalamic hemorrhage by X-CT and/or MRI scan. Regional cerebral blood flow and cerebral metabolic rate of oxygen were measured by PET using C 15 O 2 and 15 O 2 steady state inhalation technique. In the left thalamic stroke group, CMRO 2 was significantly decreased in the left cingulate, superior frontal, superior temporal, middle temporal, medial occipital, and thalamic regions, compared with the normal control group. In the right thalamic stroke group, CMRO 2 was decreased in the left cingulate, medial occipital, right hippocampal, thalamic, and the bilateral cerebellar regions, compared with the normal control group. In the left thalamic stroke group, CBF was decreased significantly in the left cingulate, middle temporal, hippocampal, thalamic, and right cerebellar regions, compared with the normal control group. In the right thalamic stroke group, CBF was significantly decreased in the right hippocampal, thalamic and left cerebellar regions compared with the normal control group. These results indicate that CBF and CMRO 2 decrease in some distant regions from thalamic lesions, perhaps due to a disconnection of neuronal fiber. Especially in the left thalamic stroke group, CMRO 2 was decreased in the ipsilateral temporal regions. This result suggests that there are more intimate functional fiber connections between the thalamus and temporal cortex in the left hemisphere than in the right hemisphere. (author)

  12. Caffeine reduces dipyridamole-induced myocardial ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Smits, P.; Aengevaeren, W.R.; Corstens, F.H.; Thien, T. (Univ. of Nijmegen (Netherlands))

    1989-10-01

    The mechanism of action of coronary vasodilation after dipyridamole may be based on inhibition of cellular uptake of circulating endogenous adenosine. Since caffeine has been reported to be a competitive antagonist of adenosine we studied the effect of caffeine on the outcome of dipiridamole-{sup 201}Tl cardiac imaging in one patient. During caffeine abstinence dipyridamole induced myocardial ischemia with down-slope ST depressions on the ECG, and reversible perfusion defects on the scintigrams. When the test was repeated 1 wk later on similar conditions, but now shortly after infusion of caffeine (4 mg/kg), the ECG showed nodepressions, and the scintigrams only slight signs of ischemia. We conclude that when caffeine abstinence is not sufficient, the widespread use of coffee and related products may be responsible for false-negative findings in dipyridamole-201Tl cardiac imaging.

  13. Caffeine reduces dipyridamole-induced myocardial ischemia

    International Nuclear Information System (INIS)

    Smits, P.; Aengevaeren, W.R.; Corstens, F.H.; Thien, T.

    1989-01-01

    The mechanism of action of coronary vasodilation after dipyridamole may be based on inhibition of cellular uptake of circulating endogenous adenosine. Since caffeine has been reported to be a competitive antagonist of adenosine we studied the effect of caffeine on the outcome of dipiridamole- 201 Tl cardiac imaging in one patient. During caffeine abstinence dipyridamole induced myocardial ischemia with down-slope ST depressions on the ECG, and reversible perfusion defects on the scintigrams. When the test was repeated 1 wk later on similar conditions, but now shortly after infusion of caffeine (4 mg/kg), the ECG showed nodepressions, and the scintigrams only slight signs of ischemia. We conclude that when caffeine abstinence is not sufficient, the widespread use of coffee and related products may be responsible for false-negative findings in dipyridamole-201Tl cardiac imaging

  14. Experimental Focal Cerebral Ischemia

    DEFF Research Database (Denmark)

    Christensen, Thomas

    2007-01-01

    Focal cerebral ischemia due to occlusion of a major cerebral artery is the cause of ischemic stroke which is a major reason of mortality, morbidity and disability in the populations of the developed countries. In the seven studies summarized in the thesis focal ischemia in rats induced by occlusion...... in the penumbra is recruited in the infarction process leading to a progressive growth of the infarct. The penumbra hence constitutes an important target for pharmacological treatment because of the existence of a therapeutic time window during which treatment with neuroprotective compounds may prevent...

  15. Serotonin gating of cortical and thalamic glutamate inputs onto principal neurons of the basolateral amygdala.

    Science.gov (United States)

    Guo, Ji-Dong; O'Flaherty, Brendan M; Rainnie, Donald G

    2017-11-01

    The basolateral amygdala (BLA) is a key site for crossmodal association of sensory stimuli and an important relay in the neural circuitry of emotion. Indeed, the BLA receives substantial glutamatergic inputs from multiple brain regions including the prefrontal cortex and thalamic nuclei. Modulation of glutamatergic transmission in the BLA regulates stress- and anxiety-related behaviors. Serotonin (5-HT) also plays an important role in regulating stress-related behavior through activation of both pre- and postsynaptic 5-HT receptors. Multiple 5-HT receptors are expressed in the BLA, where 5-HT has been reported to modulate glutamatergic transmission. However, the 5-HT receptor subtype mediating this effect is not yet clear. The aim of this study was to use patch-clamp recordings from BLA neurons in an ex vivo slice preparation to examine 1) the effect of 5-HT on extrinsic sensory inputs, and 2) to determine if any pathway specificity exists in 5-HT regulation of glutamatergic transmission. Two independent input pathways into the BLA were stimulated: the external capsule to mimic cortical input, and the internal capsule to mimic thalamic input. Bath application of 5-HT reversibly reduced the amplitude of evoked excitatory postsynaptic currents (eEPSCs) induced by stimulation of both pathways. The decrease was associated with an increase in the paired-pulse ratio and coefficient of variation of eEPSC amplitude, suggesting 5-HT acts presynaptically. Moreover, the effect of 5-HT in both pathways was mimicked by the selective 5-HT 1B receptor agonist CP93129, but not by the 5-HT 1A receptor agonist 8-OH DPAT. Similarly the effect of exogenous 5-HT was blocked by the 5-HT 1B receptor antagonist GR55562, but not affected by the 5-HT 1A receptor antagonist WAY 100635 or the 5-HT 2 receptor antagonists pirenperone and MDL 100907. Together these data suggest 5-HT gates cortical and thalamic glutamatergic inputs into the BLA by activating presynaptic 5-HT 1B receptors

  16. Decoding thalamic afferent input using microcircuit spiking activity.

    Science.gov (United States)

    Sederberg, Audrey J; Palmer, Stephanie E; MacLean, Jason N

    2015-04-01

    A behavioral response appropriate to a sensory stimulus depends on the collective activity of thousands of interconnected neurons. The majority of cortical connections arise from neighboring neurons, and thus understanding the cortical code requires characterizing information representation at the scale of the cortical microcircuit. Using two-photon calcium imaging, we densely sampled the thalamically evoked response of hundreds of neurons spanning multiple layers and columns in thalamocortical slices of mouse somatosensory cortex. We then used a biologically plausible decoder to characterize the representation of two distinct thalamic inputs, at the level of the microcircuit, to reveal those aspects of the activity pattern that are likely relevant to downstream neurons. Our data suggest a sparse code, distributed across lamina, in which a small population of cells carries stimulus-relevant information. Furthermore, we find that, within this subset of neurons, decoder performance improves when noise correlations are taken into account. Copyright © 2015 the American Physiological Society.

  17. Dopamine, fronto-striato-thalamic circuits and risk for psychosis.

    Science.gov (United States)

    Dandash, Orwa; Pantelis, Christos; Fornito, Alex

    2017-02-01

    A series of parallel, integrated circuits link distinct regions of prefrontal cortex with specific nuclei of the striatum and thalamus. Dysfunction of these fronto-striato-thalamic systems is thought to play a major role in the pathogenesis of psychosis. In this review, we examine evidence from human and animal investigations that dysfunction of a specific dorsal fronto-striato-thalamic circuit, linking the dorsolateral prefrontal cortex, dorsal (associative) striatum, and mediodorsal nucleus of the thalamus, is apparent across different stages of psychosis, including prior to the onset of a first episode, suggesting that it represents a candidate risk biomarker. We consider how abnormalities at distinct points in the circuit may give rise to the pattern of findings seen in patient populations, and how these changes relate to disruptions in dopamine, glutamate and GABA signaling. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Holmes' tremor as a delayed complication of thalamic stroke.

    Science.gov (United States)

    Martins, William Alves; Marrone, Luiz Carlos Porcello; Fussiger, Helena; Vedana, Viviane Maria; Cristovam, Rafael do Amaral; Taietti, Marjorye Z; Marrone, Antonio Carlos Huf

    2016-04-01

    Movement disorders are not commonly associated with stroke. Accordingly, thalamic strokes have rarely been associated with tremor, pseudo-athetosis and dystonic postures. We present a 75-year-old man who developed a disabling tremor 1 year after a posterolateral thalamic stroke. This tremor had low frequency (3-4 Hz), did not disappear on focus and was exacerbated by maintaining a static posture and on target pursuit, which made it very difficult to perform basic functions. MRI demonstrated an old ischemic lesion at the left posterolateral thalamus. Treatment with levodopa led to symptom control. Lesions in the midbrain, cerebellum and thalamus may cause Holmes' tremor. Delayed onset of symptoms is usually seen, sometimes appearing 2 years after the original injury. This may be due to maturation of a complex neuronal network, leading to slow dopaminergic denervation. Further studies are needed to improve our understanding of this unique disconnection syndrome. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Migraine and ischemia

    NARCIS (Netherlands)

    van der Wammes-van der Heijden, E.A.

    2009-01-01

    An association between migraine and ischemic events, especially ischemic stroke, has been debated for many years. Whether migraine is a risk factor for ischemic events or ischemia triggers migraine, or both, is still unclear. This thesis explores different relationships between migraine and

  20. What does a comparison of the alcoholic Korsakoff syndrome and thalamic infarction tell us about thalamic amnesia?

    Science.gov (United States)

    Kopelman, Michael D

    2015-07-01

    In this review, the clinical, neuropsychological, and neuroimaging findings in the alcoholic Korsakoff syndrome and in thalamic amnesia, resulting from focal infarction, are compared. In both disorders, there is controversy over what is the critical site for anterograde amnesia to occur-damage to the anterior thalamus/mammillo-thalamic tract has most commonly been cited, but damage to the medio-dorsal nuclei has also been advocated. Both syndromes show 'core' features of an anterograde amnesic syndrome; but retrograde amnesia is generally much more extensive (going back many years or decades) in the Korsakoff syndrome. Likewise, spontaneous confabulation occurs more commonly in the Korsakoff syndrome, although seen in only a minority of chronic cases. These differences are attributed to the greater prevalence of frontal atrophy and frontal damage in Korsakoff cases. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.

  1. Hypertensive thalamic hematoma treated by CT stereotactic evacuation (with two cases reports)

    International Nuclear Information System (INIS)

    Wang Hongsheng; Zhu Fengqing

    2002-01-01

    Objective: To investigate new surgical method to treat hypertensive thalamic hematoma. Methods: Two medial-degree coma patients with hypertensive thalamic hematoma were treated by CT stereotactic evacuation. Results: One week after operation the two patients regained consciousness. The function of paraplegic appendage restored partly, and one patient could take care of himself. Conclusion: CT stereotactic evacuation to treat hypertensive thalamic hematoma has the advantages of small trauma, little complication and good clinical results. The authors suggest that it be selected firstly in treating hypertensive thalamic hematoma

  2. Pre-stimulus thalamic theta power predicts human memory formation.

    Science.gov (United States)

    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    Pre-stimulus theta (4-8Hz) power in the hippocampus and neocortex predicts whether a memory for a subsequent event will be formed. Anatomical studies reveal thalamus-hippocampal connectivity, and lesion, neuroimaging, and electrophysiological studies show that memory processing involves the dorsomedial (DMTN) and anterior thalamic nuclei (ATN). The small size and deep location of these nuclei have limited real-time study of their activity, however, and it is unknown whether pre-stimulus theta power predictive of successful memory formation is also found in these subcortical structures. We recorded human electrophysiological data from the DMTN and ATN of 7 patients receiving deep brain stimulation for refractory epilepsy. We found that greater pre-stimulus theta power in the right DMTN was associated with successful memory encoding, predicting both behavioral outcome and post-stimulus correlates of successful memory formation. In particular, significant correlations were observed between right DMTN theta power and both frontal theta and right ATN gamma (32-50Hz) phase alignment, and frontal-ATN theta-gamma cross-frequency coupling. We draw the following primary conclusions. Our results provide direct electrophysiological evidence in humans of a role for the DMTN as well as the ATN in memory formation. Furthermore, prediction of subsequent memory performance by pre-stimulus thalamic oscillations provides evidence that post-stimulus differences in thalamic activity that index successful and unsuccessful encoding reflect brain processes specifically underpinning memory formation. Finally, the findings broaden the understanding of brain states that facilitate memory encoding to include subcortical as well as cortical structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Multicentre European study of thalamic stimulation in parkinsonian and essential tremor

    NARCIS (Netherlands)

    Limousin, P.; Speelman, J. D.; Gielen, F.; Janssens, M.

    1999-01-01

    Thalamic stimulation has been proposed to treat disabling tremor. The aims of this multicentre study were to evaluate the efficacy and the morbidity of thalamic stimulation in a large number of patients with parkinsonian or essential tremor. One hundred and eleven patients were included in the study

  4. Prognosis of thalamic hemorrhage evaluated by computed tomography

    International Nuclear Information System (INIS)

    Takahashi, Shinichiro; Sonobe, Makoto; Sugita, Kyoichi; Kuwayama, Naoya

    1984-01-01

    The present authors have analyzed the correlation between the clinical features and the CT findings in 66 cases of thalamic hemorrhage. Hitachi CT-H and CT-HF apparatuses (256 x 256 matrix) were used at an angle parallel to the OM line. Of the 48 patients with hematoma less than 20 ml, only four died; however, of the 18 patients with hematoma larger than 20 ml, five died. An analysis has been made of the correlation between the occurrence of brain edema in the acute stage and high density in the subthalamic area. The hematoma extending to the subthalamic area was diagnosed by means of high density at the level of 35 mm above the OM line. Of the 13 cases with hematoma in the subthalamic area, acute brain edema occurred in 9 cases. On the other hand, of the 53 cases without hematoma at the subthalamic area, brain edema occurred in only one case. It was concluded that high density in the subthalamic area is a significant index for the occurrence of acute brain edema in a thalamic hemorrhage. (author)

  5. Cerebral blood flow and cerebral oxygen metabolism in thalamic hemorrhage

    International Nuclear Information System (INIS)

    Yasui, Nobuyuki; Asakura, Ken

    1987-01-01

    Cerebral blood flow (CBF), cerebral oxygen consumption (CMRO 2 ), oxygen extraction fraction (OEF) and cerebral blood volume (CBV) were studied in 20 cases of thalamic hemorrhage using positron CT and 15 O labeled gas steady-state inhalation method. CBF reduction was limited around the thalamus in the small sized hematoma. CBF were significantly diminished in the mean cortical, parietal, temporal, basal ganglia and thalamic area ipsilateral and cerebellar cortex contralateral to the medium sized hematoma. There was bilateral and diffuse CBF reduction in the large sized hematoma which was caused by increased intracranial pressure. CMRO 2 value were similary changed as CBF. OEF change showed within normal limit. Diffuse CBV reduction was observed in the large sized hematoma. This reduction was the result of decreased vascular bed caused by mass effect of the hematoma and hydrocephalus. Effect of surgical treatment such as ventricular drainage and hematoma evacuation were also discussed in correlation to CBF in some case using positron and single photon ECT. (author)

  6. Thalamic, brainstem, and cerebellar glucose metabolism in the hemiplegic monkey

    Energy Technology Data Exchange (ETDEWEB)

    Shimoyama, I.; Dauth, G.W.; Gilman, S.; Frey, K.A.; Penney, J.B. Jr.

    1988-12-01

    Unilateral ablation of cerebral cortical areas 4 and 6 of Brodmann in the macaque monkey results in a contralateral hemiplegia that resolves partially with time. During the phase of dense hemiplegia, local cerebral metabolic rate for glucose (1CMRG1c) is decreased significantly in most of the thalamic nuclei ipsilateral to the ablation, and there are slight contralateral decreases. The lCMRGlc is reduced bilaterally in most of the brainstem nuclei and bilaterally in the deep cerebellar nuclei, but only in the contralateral cerebellar cortex. During the phase of partial motor recovery, lCMRGlc is incompletely restored in many of the thalamic nuclei ipsilateral to the ablation and completely restored in the contralateral nuclei. In the brainstem and deep cerebellar nuclei, poor to moderate recovery occurs bilaterally. Moderate recovery occurs in the contralateral cerebellar cortex. The findings demonstrate that a unilateral cerebral cortical lesion strongly affects lCMRGlc in the thalamus ipsilaterally and in the cerebellar cortex contralaterally, but in the brainstem bilaterally. Partial recovery of lCMRGlc accompanies the progressive motor recovery. The structures affected include those with direct, and also those with indirect, connections to the areas ablated.

  7. From Parkinsonian thalamic activity to restoring thalamic relay using deep brain stimulation: new insights from computational modeling

    Science.gov (United States)

    Meijer, H. G. E.; Krupa, M.; Cagnan, H.; Lourens, M. A. J.; Heida, T.; Martens, H. C. F.; Bour, L. J.; van Gils, S. A.

    2011-10-01

    We present a computational model of a thalamocortical relay neuron for exploring basal ganglia thalamocortical loop behavior in relation to Parkinson's disease and deep brain stimulation (DBS). Previous microelectrode, single-unit recording studies demonstrated that oscillatory interaction within and between basal ganglia nuclei is very often accompanied by synchronization at Parkinsonian rest tremor frequencies (3-10 Hz). These oscillations have a profound influence on thalamic projections and impair the thalamic relaying of cortical input by generating rebound action potentials. Our model describes convergent inhibitory input received from basal ganglia by the thalamocortical cells based on characteristics of normal activity, and/or low-frequency oscillations (activity associated with Parkinson's disease). In addition to simulated input, we also used microelectrode recordings as inputs for the model. In the resting state, and without additional sensorimotor input, pathological rebound activity is generated for even mild Parkinsonian input. We have found a specific stimulation window of amplitudes and frequencies for periodic input, which corresponds to high-frequency DBS, and which also suppresses rebound activity for mild and even more prominent Parkinsonian input. When low-frequency pathological rebound activity disables the thalamocortical cell's ability to relay excitatory cortical input, a stimulation signal with parameter settings corresponding to our stimulation window can restore the thalamocortical cell's relay functionality.

  8. [Multiple coronary fistulas to the left ventricle. An unusual cause of myocardial ischemia].

    Science.gov (United States)

    Piovaccari, G; Melandri, G; Marzocchi, A; Scarfoglio, D; Sanguinetti, M; Magnani, B

    1989-04-01

    Diffuse communications between the left coronary artery and the left ventricular cavity were found in a 54-years-old man presenting with angina pectoris and reversible ischemia documented on stress Thallium scintigraphy. During atrial pacing the patient experienced chest pain which was accompanied by lactate production. Atenolol, but not nifedipine, did ameliorate the symptoms. The anatomical types and the embriogenesis of coronary microfistulas along with possible mechanisms of ischemia are discussed.

  9. Unified thalamic model generates multiple distinct oscillations with state-dependent entrainment by stimulation.

    Directory of Open Access Journals (Sweden)

    Guoshi Li

    2017-10-01

    Full Text Available The thalamus plays a critical role in the genesis of thalamocortical oscillations, yet the underlying mechanisms remain elusive. To understand whether the isolated thalamus can generate multiple distinct oscillations, we developed a biophysical thalamic model to test the hypothesis that generation of and transition between distinct thalamic oscillations can be explained as a function of neuromodulation by acetylcholine (ACh and norepinephrine (NE and afferent synaptic excitation. Indeed, the model exhibited four distinct thalamic rhythms (delta, sleep spindle, alpha and gamma oscillations that span the physiological states corresponding to different arousal levels from deep sleep to focused attention. Our simulation results indicate that generation of these distinct thalamic oscillations is a result of both intrinsic oscillatory cellular properties and specific network connectivity patterns. We then systematically varied the ACh/NE and input levels to generate a complete map of the different oscillatory states and their transitions. Lastly, we applied periodic stimulation to the thalamic network and found that entrainment of thalamic oscillations is highly state-dependent. Our results support the hypothesis that ACh/NE modulation and afferent excitation define thalamic oscillatory states and their response to brain stimulation. Our model proposes a broader and more central role of the thalamus in the genesis of multiple distinct thalamo-cortical rhythms than previously assumed.

  10. Effects of donepezil on behavioural manifestations of thalamic infarction: a single case observation

    Directory of Open Access Journals (Sweden)

    Rodrigo eRiveros

    2011-03-01

    Full Text Available Objective: To examine the effect of donepezil for the treatment of cognitive and behavioural disorders associated with thalamic lesions in a 45 years old male who suffered an infarct in the left thalamus. Background: Recent studies suggest that donepezil may improve executive functions impairments due to subcortical ischemic lesionsMethod: The crossover effects of donepezil were analyzed in a single case of thalamic infarction with cognitive and behavioural alterations. Results: Significant behavioural modifications related to improved performances in executive functions were observed with the treatment. Conclusions: The results suggest that donepezil may have significant effect on executive functions that can alter behavioural outcomes after thalamic infarctions

  11. Thalamic Ventral Intermediate Nucleus Deep Brain Stimulation for Orthostatic Tremor

    Directory of Open Access Journals (Sweden)

    Alexander C. Lehn

    2017-07-01

    Full Text Available Background: Orthostatic tremor (OT was first described in 1977. It is characterized by rapid tremor of 13–18 Hz and can be recorded in the lower limbs and trunk muscles. OT remains difficult to treat, although some success has been reported with deep brain stimulation (DBS.Case Report: We report a 68-year-old male with OT who did not improve significantly after bilateral thalamic stimulation.Discussion: Although some patients were described who improved after DBS surgery, more information is needed about the effect of these treatment modalities on OT, ideally in the form of randomized trial data. 

  12. Thalamic Volume Is Reduced in Cervical and Laryngeal Dystonias.

    Science.gov (United States)

    Waugh, Jeff L; Kuster, John K; Levenstein, Jacob M; Makris, Nikos; Multhaupt-Buell, Trisha J; Sudarsky, Lewis R; Breiter, Hans C; Sharma, Nutan; Blood, Anne J

    2016-01-01

    Dystonia, a debilitating movement disorder characterized by abnormal fixed positions and/or twisting postures, is associated with dysfunction of motor control networks. While gross brain lesions can produce secondary dystonias, advanced neuroimaging techniques have been required to identify network abnormalities in primary dystonias. Prior neuroimaging studies have provided valuable insights into the pathophysiology of dystonia, but few directly assessed the gross volume of motor control regions, and to our knowledge, none identified abnormalities common to multiple types of idiopathic focal dystonia. We used two gross volumetric segmentation techniques and one voxelwise volumetric technique (voxel based morphometry, VBM) to compare regional volume between matched healthy controls and patients with idiopathic primary focal dystonia (cervical, n = 17, laryngeal, n = 7). We used (1) automated gross volume measures of eight motor control regions using the FreeSurfer analysis package; (2) blinded, anatomist-supervised manual segmentation of the whole thalamus (also gross volume); and (3) voxel based morphometry, which measures local T1-weighted signal intensity and estimates gray matter density or volume at the level of single voxels, for both whole-brain and thalamus. Using both automated and manual gross volumetry, we found a significant volume decrease only in the thalamus in two focal dystonias. Decreases in whole-thalamic volume were independent of head and brain size, laterality of symptoms, and duration. VBM measures did not differ between dystonia and control groups in any motor control region. Reduced thalamic gross volume, detected in two independent analyses, suggests a common anatomical abnormality in cervical dystonia and spasmodic dysphonia. Defining the structural underpinnings of dystonia may require such complementary approaches.

  13. Thalamic Volume Is Reduced in Cervical and Laryngeal Dystonias.

    Directory of Open Access Journals (Sweden)

    Jeff L Waugh

    Full Text Available Dystonia, a debilitating movement disorder characterized by abnormal fixed positions and/or twisting postures, is associated with dysfunction of motor control networks. While gross brain lesions can produce secondary dystonias, advanced neuroimaging techniques have been required to identify network abnormalities in primary dystonias. Prior neuroimaging studies have provided valuable insights into the pathophysiology of dystonia, but few directly assessed the gross volume of motor control regions, and to our knowledge, none identified abnormalities common to multiple types of idiopathic focal dystonia.We used two gross volumetric segmentation techniques and one voxelwise volumetric technique (voxel based morphometry, VBM to compare regional volume between matched healthy controls and patients with idiopathic primary focal dystonia (cervical, n = 17, laryngeal, n = 7. We used (1 automated gross volume measures of eight motor control regions using the FreeSurfer analysis package; (2 blinded, anatomist-supervised manual segmentation of the whole thalamus (also gross volume; and (3 voxel based morphometry, which measures local T1-weighted signal intensity and estimates gray matter density or volume at the level of single voxels, for both whole-brain and thalamus.Using both automated and manual gross volumetry, we found a significant volume decrease only in the thalamus in two focal dystonias. Decreases in whole-thalamic volume were independent of head and brain size, laterality of symptoms, and duration. VBM measures did not differ between dystonia and control groups in any motor control region.Reduced thalamic gross volume, detected in two independent analyses, suggests a common anatomical abnormality in cervical dystonia and spasmodic dysphonia. Defining the structural underpinnings of dystonia may require such complementary approaches.

  14. Thalamic Volume Is Reduced in Cervical and Laryngeal Dystonias

    Science.gov (United States)

    Waugh, Jeff L.; Kuster, John K.; Levenstein, Jacob M.; Makris, Nikos; Multhaupt-Buell, Trisha J.; Sudarsky, Lewis R.; Breiter, Hans C.; Sharma, Nutan; Blood, Anne J.

    2016-01-01

    Background Dystonia, a debilitating movement disorder characterized by abnormal fixed positions and/or twisting postures, is associated with dysfunction of motor control networks. While gross brain lesions can produce secondary dystonias, advanced neuroimaging techniques have been required to identify network abnormalities in primary dystonias. Prior neuroimaging studies have provided valuable insights into the pathophysiology of dystonia, but few directly assessed the gross volume of motor control regions, and to our knowledge, none identified abnormalities common to multiple types of idiopathic focal dystonia. Methods We used two gross volumetric segmentation techniques and one voxelwise volumetric technique (voxel based morphometry, VBM) to compare regional volume between matched healthy controls and patients with idiopathic primary focal dystonia (cervical, n = 17, laryngeal, n = 7). We used (1) automated gross volume measures of eight motor control regions using the FreeSurfer analysis package; (2) blinded, anatomist-supervised manual segmentation of the whole thalamus (also gross volume); and (3) voxel based morphometry, which measures local T1-weighted signal intensity and estimates gray matter density or volume at the level of single voxels, for both whole-brain and thalamus. Results Using both automated and manual gross volumetry, we found a significant volume decrease only in the thalamus in two focal dystonias. Decreases in whole-thalamic volume were independent of head and brain size, laterality of symptoms, and duration. VBM measures did not differ between dystonia and control groups in any motor control region. Conclusions Reduced thalamic gross volume, detected in two independent analyses, suggests a common anatomical abnormality in cervical dystonia and spasmodic dysphonia. Defining the structural underpinnings of dystonia may require such complementary approaches. PMID:27171035

  15. Sensory disturbance, CT, and somatosensory evoked potentials in thalamic hemorrhages

    International Nuclear Information System (INIS)

    Koga, Hisanobu; Miyazaki, Takayoshi; Miyazaki, Hisaya

    1985-01-01

    Thalamic hemorrhages often lead to sensory disturbances. However, no effective method for the evaluation of their prognoses has yet been clinically utilized. The somatosensory evoked potential (SEP) has been reported as an effective method, but it remains controversial. A CT scan is eminently suitable for determining the size and position of the hemorrhage. However, the correlation between the localization of the hematoma on the CT scan and the sensory distrubance has not been investigated fully. The authors selected 20 cases with the chronic stage of a thalamic hemorrhage. Each one was clinically evaluated as to sensory disturbance; they were then classified into the following five groups: Group 1: no sensory deficit (3 cases); Group 2: complete recovery from initial deficit (2 cases); Group 3: mild hypesthesia (5 cases); Group 4: severe hypesthesia (5 cases), and Group 5: paresthesia or dysesthesia (5 cases). Also, the CT scan was investigated with regard to the localization of the hematoma and the SEP. We could thus find a characteristic pattern in each group. The results may be summarized as follows. 1. The correlation between the degree of the sensory disturbance and the size and expansion of the hematoma was clearly detected. Especially, the most severe sensory disturbance was found in the hematoma extending to the lateral nuclear and ventral nuclear regions. 2. In Group 1 and 2, each SEP component (N 1 N 2 N 3 ) was shown to be normal. In Group 3, SEP components could be detected, but not completely. In Group 4, no components at all could be found. 3. In Group 5, all cases were small hematoma localized in the lateral nuclear region of the thalamus, while the N 3 components were prolonged on the SEP findings. The authors demonstrate the results and discuss the correlation between the sensory disturbance and the CT or SEP findings. (author)

  16. Myocardial ischemia in hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Lima Filho, Moyses de Oliveira; Figueiredo, Geraldo L.; Simoes, Marcus V.; Pyntia, Antonio O.; Marin Neto, Jose Antonio

    2000-01-01

    Myocardial ischemia in hypertrophic cardiomyopathy is multifactorial and explains the occurrence of angina, in about 50% of patients. The pathophysiology of myocardial ischemia may be explained by the increase of the ventricular mass and relative paucity of the coronary microcirculation; the elevated ventricular filling pressures and myocardial stiffness causing a compression of the coronary microvessels; the impaired coronary vasodilator flow reserve caused by anatomic and functional abnormalities; and the systolic compression of epicardial vessel (myocardial bridges). Myocardial ischemia must be investigated by perfusion scintigraphic methods since its presence influences the prognosis and has relevant clinical implications for management of patients. Patients with hypertrophic cardiomyopathy and documented myocardial ischemia usually need to undergo invasive coronary angiography to exclude the presence of concomitant atherosclerotic coronary disease. (author)

  17. Multivoxel proton magnetic resonance spectroscopy detects thalamic neurochemical metabolic changes in patients with major depressive disorder

    Directory of Open Access Journals (Sweden)

    Rania E. Mohamed

    2017-06-01

    Conclusion: The multi-voxel 1H-MRS can provide an insight to the neurochemical metabolic changes occurring in both thalami in patients with MDD. Increased severity of depression is significantly related to these thalamic neurochemical changes.

  18. Cerebellar Ataxia from Multiple Potential Causes: Hypothyroidism, Hashimoto's Thyroiditis, Thalamic Stimulation, and Essential Tremor

    OpenAIRE

    Shneyder, Natalya; Lyons, Mark K.; Driver-dunckley, Erika; Evidente, Virgilio Gerald H.

    2012-01-01

    Background: Both hypothyroidism and Hashimoto's thyroiditis (HT) can rarely be associated with cerebellar ataxia. Severe essential tremor (ET) as well as bilateral thalamic deep brain stimulation (DBS) may lead to subtle cerebellar signs. Case Report: We report a 74-year-old male with hypothyroidism and a 20-year history of ET who developed cerebellar ataxia after bilateral thalamic DBS. Extensive workup revealed elevated thyroid stimulating hormone and thyroperoxidase antibody titers c...

  19. Grey matter volume patterns in thalamic nuclei are associated with familial risk for schizophrenia.

    Science.gov (United States)

    Pergola, Giulio; Trizio, Silvestro; Di Carlo, Pasquale; Taurisano, Paolo; Mancini, Marina; Amoroso, Nicola; Nettis, Maria Antonietta; Andriola, Ileana; Caforio, Grazia; Popolizio, Teresa; Rampino, Antonio; Di Giorgio, Annabella; Bertolino, Alessandro; Blasi, Giuseppe

    2017-02-01

    Previous evidence suggests reduced thalamic grey matter volume (GMV) in patients with schizophrenia (SCZ). However, it is not considered an intermediate phenotype for schizophrenia, possibly because previous studies did not assess the contribution of individual thalamic nuclei and employed univariate statistics. Here, we hypothesized that multivariate statistics would reveal an association of GMV in different thalamic nuclei with familial risk for schizophrenia. We also hypothesized that accounting for the heterogeneity of thalamic GMV in healthy controls would improve the detection of subjects at familial risk for the disorder. We acquired MRI scans for 96 clinically stable SCZ, 55 non-affected siblings of patients with schizophrenia (SIB), and 249 HC. The thalamus was parceled into seven regions of interest (ROIs). After a canonical univariate analysis, we used GMV estimates of thalamic ROIs, together with total thalamic GMV and premorbid intelligence, as features in Random Forests to classify HC, SIB, and SCZ. Then, we computed a Misclassification Index for each individual and tested the improvement in SIB detection after excluding a subsample of HC misclassified as patients. Random Forests discriminated SCZ from HC (accuracy=81%) and SIB from HC (accuracy=75%). Left anteromedial thalamic volumes were significantly associated with both multivariate classifications (p<0.05). Excluding HC misclassified as SCZ improved greatly HC vs. SIB classification (Cohen's d=1.39). These findings suggest that multivariate statistics identify a familial background associated with thalamic GMV reduction in SCZ. They also suggest the relevance of inter-individual variability of GMV patterns for the discrimination of individuals at familial risk for the disorder. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Thalamic physiology of intentional essential tremor is more like cerebellar tremor than postural essential tremor

    OpenAIRE

    Zakaria, R; Lenz, FA; Hua, S; Avin, BH; Liu, CC; Mari, Z

    2013-01-01

    The neuronal physiological correlates of clinical heterogeneity in human essential tremor are unknown. We now test the hypothesis that thalamic neuronal and EMG activities during intention essential tremor are similar to those of the intention tremor which is characteristic of cerebellar lesions. Thalamic neuronal firing was studied in a cerebellar relay nucleus (ventral intermediate, Vim) and in a pallidal relay nucleus (ventral oral posterior, Vop) during stereotactic surgery for the treatm...

  1. Thalamic lesions in multiple sclerosis by 7T MRI: Clinical implications and relationship to cortical pathology.

    Science.gov (United States)

    Harrison, Daniel M; Oh, Jiwon; Roy, Snehashis; Wood, Emily T; Whetstone, Anna; Seigo, Michaela A; Jones, Craig K; Pham, Dzung; van Zijl, Peter; Reich, Daniel S; Calabresi, Peter A

    2015-08-01

    Pathology in both cortex and deep gray matter contribute to disability in multiple sclerosis (MS). We used the increased signal-to-noise ratio of 7-tesla (7T) MRI to visualize small lesions within the thalamus and to relate this to clinical information and cortical lesions. We obtained 7T MRI scans on 34 MS cases and 15 healthy volunteers. Thalamic lesion number and volume were related to demographic data, clinical disability measures, and lesions in cortical gray matter. Thalamic lesions were found in 24/34 of MS cases. Two lesion subtypes were noted: discrete, ovoid lesions, and more diffuse lesional areas lining the periventricular surface. The number of thalamic lesions was greater in progressive MS compared to relapsing-remitting (mean ±SD, 10.7 ±0.7 vs. 3.0 ±0.7, respectively, p < 0.001). Thalamic lesion burden (count and volume) correlated with EDSS score and measures of cortical lesion burden, but not with white matter lesion burden or white matter volume. Using 7T MRI allows identification of thalamic lesions in MS, which are associated with disability, progressive disease, and cortical lesions. Thalamic lesion analysis may be a simpler, more rapid estimate of overall gray matter lesion burden in MS. © The Author(s), 2015.

  2. Neuronal network disturbance after focal ischemia in rats

    International Nuclear Information System (INIS)

    Kataoka, K.; Hayakawa, T.; Yamada, K.; Mushiroi, T.; Kuroda, R.; Mogami, H.

    1989-01-01

    We studied functional disturbances following left middle cerebral artery occlusion in rats. Neuronal function was evaluated by [14C]2-deoxyglucose autoradiography 1 day after occlusion. We analyzed the mechanisms of change in glucose utilization outside the infarct using Fink-Heimer silver impregnation, axonal transport of wheat germ agglutinin-conjugated-horseradish peroxidase, and succinate dehydrogenase histochemistry. One day after occlusion, glucose utilization was remarkably reduced in the areas surrounding the infarct. There were many silver grains indicating degeneration of the synaptic terminals in the cortical areas surrounding the infarct and the ipsilateral cingulate cortex. Moreover, in the left thalamus where the left middle cerebral artery supplied no blood, glucose utilization significantly decreased compared with sham-operated rats. In the left thalamus, massive silver staining of degenerated synaptic terminals and decreases in succinate dehydrogenase activity were observed 4 and 5 days after occlusion. The absence of succinate dehydrogenase staining may reflect early changes in retrograde degeneration of thalamic neurons after ischemic injury of the thalamocortical pathway. Terminal degeneration even affected areas remote from the infarct: there were silver grains in the contralateral hemisphere transcallosally connected to the infarct and in the ipsilateral substantia nigra. Axonal transport study showed disruption of the corticospinal tract by subcortical ischemia; the transcallosal pathways in the cortex surrounding the infarct were preserved. The relation between neural function and the neuronal network in the area surrounding the focal cerebral infarct is discussed with regard to ischemic penumbra and diaschisis

  3. Sequential changes in ischemic edema following transient focal cerebral ischemia in rats; Magnetic resonance imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Nagahiro, Shinji; Goto, Satoshi; Kogo, Kasei; Sumi, Minako; Takahashi, Mutsumasa; Ushio, Yukitaka [Kumamoto Univ. (Japan). School of Medicine

    1994-07-01

    Sequential and regional changes in ischemic edema following various durations of focal cerebral ischemia were studied by magnetic resonance (MR) imaging in a rat unilateral intraluminal middle cerebral artery occlusion model. Occlusion was performed from 5 minutes to 5 hours. T[sub 2]-weighted images were obtained chronologically 6 hours after onset of ischemia, on day 1 and day 7. An immunohistochemical study using antibodies to calcineurin and glial fibrillary acidic protein was performed to observe histological changes in the ischemic brain. The T[sub 2] high-signal-intensity areas representing ischemic edema were observed in the lateral striatum and/or the cerebral cortex by day 1 in all rats with 1- to 5-hour ischemia, and the areas were larger and detected earlier with longer durations of ischemia. In three of six rats with 15-minute ischemia and five of six rats with 30-minute ischemia, the T[sub 2] high-signal-intensity areas appeared transiently on day 1 in the dorsolateral striatum where loss of neurons expressing calcineurin immunoreactivity and associated gliosis were found. MR imaging in animal models of reversible focal ischemia can achieve sequential and noninvasive evaluation of dynamic regional changes in ischemic edema. (author).

  4. Reverse Algols

    Science.gov (United States)

    Leung, K. C.

    1989-01-01

    Reverse Algols, binary systems with a semidetached configuration in which the more massive component is in contact with the critical equipotential surface, are examined. Observational evidence for reverse Algols is presented and the parameters of seven reverse Algols are listed. The evolution of Algols and reverse Algols is discussed. It is suggested that, because reverse Algols represent the premass-reversal semidetached phase of close binary evolution, the evolutionary time scale between regular and reverse Algols is the ratio of the number of confirmed systems of these two Algol types.

  5. Reverse Logistics

    OpenAIRE

    Kulikova, Olga

    2016-01-01

    This thesis was focused on the analysis of the concept of reverse logistics and actual reverse processes which are implemented in mining industry and finding solutions for the optimization of reverse logistics in this sphere. The objective of this paper was the assessment of the development of reverse logistics in mining industry on the example of potash production. The theoretical part was based on reverse logistics and mining waste related literature and provided foundations for further...

  6. Reduced thalamic and pontine connectivity in Kleine-Levin syndrome

    Directory of Open Access Journals (Sweden)

    Maria eEngström

    2014-04-01

    Full Text Available The Kleine-Levin syndrome is a rare sleep disorder, characterized by exceptionally long sleep episodes. The neuropathology of the syndrome is unknown and treatment is often inadequate. The aim of the study was to improve understanding of the underlying neuropathology, related to cerebral networks, in Kleine-Levin syndrome during sleep episodes. One patient with Kleine-Levin syndrome and congenital nystagmus, was investigated by resting state functional Magnetic Resonance Imaging during both asymptomatic and hypersomnic periods. Fourteen healthy subjects were also investigated as control samples. Functional connectivity was assessed from seed regions of interest in the thalamus and the dorsal pons. Thalamic connectivity was normal in the asymptomatic patient whereas the connectivity between the brain stem, including dorsal pons, and the thalamus was diminished during hypersomnia. These results suggest that the patient’s nystagmus and hypersomnia might have their pathological origin in adjacent dorsal pontine regions. This finding provides additional knowledge of the cerebral networks involved in the neuropathology of this disabling disorder. Furthermore, these findings regarding a rare syndrome have broad implications and results could be of interest to researchers and clinicians in the whole field of sleep medicine.

  7. Thalamic and parietal brain morphology predicts auditory category learning.

    Science.gov (United States)

    Scharinger, Mathias; Henry, Molly J; Erb, Julia; Meyer, Lars; Obleser, Jonas

    2014-01-01

    Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties. © 2013 Published by Elsevier Ltd.

  8. The thalamic reticular nucleus: structure, function and concept.

    Science.gov (United States)

    Pinault, Didier

    2004-08-01

    On the basis of theoretical, anatomical, psychological and physiological considerations, Francis Crick (1984) proposed that, during selective attention, the thalamic reticular nucleus (TRN) controls the internal attentional searchlight that simultaneously highlights all the neural circuits called on by the object of attention. In other words, he submitted that during either perception, or the preparation and execution of any cognitive and/or motor task, the TRN sets all the corresponding thalamocortical (TC) circuits in motion. Over the last two decades, behavioural, electrophysiological, anatomical and neurochemical findings have been accumulating, supporting the complex nature of the TRN and raising questions about the validity of this speculative hypothesis. Indeed, our knowledge of the actual functioning of the TRN is still sprinkled with unresolved questions. Therefore, the time has come to join forces and discuss some recent cellular and network findings concerning this diencephalic GABAergic structure, which plays important roles during various states of consciousness. On the whole, the present critical survey emphasizes the TRN's complexity, and provides arguments combining anatomy, physiology and cognitive psychology.

  9. Cerebral blood flow in patients with thalamic hemorrhage, 2

    International Nuclear Information System (INIS)

    Ueda, Mikiya; Matsumoto, Yukihiro; Omiya, Nobuyuki; Mikami, Junichi; Sato, Hiroyuki; Inoue, Yoshitoshi; Okawara, Shuji; Matsuoka, Takahiro; Takeda, Satoshi.

    1989-01-01

    In twenty-nine patients with thalamic hemorrhage, single photon emission CT (SPECT) and CT were performed in the acute stage. Measurement of cerebral blood flow (CBF) was performed by the 133-Xe inhalation method using SPECT (Tomomatic 64). CT findings such as hematoma volume, involvement of internal capsule, ventricular hematoma and topographical localization of hematoma were investigated. We studied etiological analysis of decreased CBF in the acute stage. CBF values in the group of large-volume hematoma (≥10 ml) decreased moderately on the hematoma side and mildly on the nonhematoma side. CBF values in the group of small-volume hematoma (<10 ml) decreased mildly on the hematoma side but didn't decrease on the nonhematoma side. CBF values of the former on the hematoma side decreased significantly compared with the latter. Linear correlation between hematoma volume and CBF was significant. As to topographical localization, CBF values of the group which involved medial thalamus decreased significantly compared with the other group. Factors of involvement of internal capsule and ventricular hematoma didn't affect CBF values. In conclusion, major factors which affected decreased CBF in the acute stage were hematoma volume and tomographical localization. (author)

  10. Getting signals into the brain: visual prosthetics through thalamic microstimulation.

    Science.gov (United States)

    Pezaris, John S; Eskandar, Emad N

    2009-07-01

    Common causes of blindness are diseases that affect the ocular structures, such as glaucoma, retinitis pigmentosa, and macular degeneration, rendering the eyes no longer sensitive to light. The visual pathway, however, as a predominantly central structure, is largely spared in these cases. It is thus widely thought that a device-based prosthetic approach to restoration of visual function will be effective and will enjoy similar success as cochlear implants have for restoration of auditory function. In this article the authors review the potential locations for stimulation electrode placement for visual prostheses, assessing the anatomical and functional advantages and disadvantages of each. Of particular interest to the neurosurgical community is placement of deep brain stimulating electrodes in thalamic structures that has shown substantial promise in an animal model. The theory of operation of visual prostheses is discussed, along with a review of the current state of knowledge. Finally, the visual prosthesis is proposed as a model for a general high-fidelity machine-brain interface.

  11. Prefrontal-Thalamic Anatomical Connectivity and Executive Cognitive Function in Schizophrenia.

    Science.gov (United States)

    Giraldo-Chica, Monica; Rogers, Baxter P; Damon, Stephen M; Landman, Bennett A; Woodward, Neil D

    2018-03-15

    Executive cognitive functions, including working memory, cognitive flexibility, and inhibition, are impaired in schizophrenia. Executive functions rely on coordinated information processing between the prefrontal cortex (PFC) and thalamus, particularly the mediodorsal nucleus. This raises the possibility that anatomical connectivity between the PFC and mediodorsal thalamus may be 1) reduced in schizophrenia and 2) related to deficits in executive function. The current investigation tested these hypotheses. Forty-five healthy subjects and 62 patients with a schizophrenia spectrum disorder completed a battery of tests of executive function and underwent diffusion-weighted imaging. Probabilistic tractography was used to quantify anatomical connectivity between six cortical regions, including PFC, and the thalamus. Thalamocortical anatomical connectivity was compared between healthy subjects and patients with schizophrenia using region-of-interest and voxelwise approaches, and the association between PFC-thalamic anatomical connectivity and severity of executive function impairment was examined in patients. Anatomical connectivity between the thalamus and PFC was reduced in schizophrenia. Voxelwise analysis localized the reduction to areas of the mediodorsal thalamus connected to lateral PFC. Reduced PFC-thalamic connectivity in schizophrenia correlated with impaired working memory but not cognitive flexibility and inhibition. In contrast to reduced PFC-thalamic connectivity, thalamic connectivity with somatosensory and occipital cortices was increased in schizophrenia. The results are consistent with models implicating disrupted PFC-thalamic connectivity in the pathophysiology of schizophrenia and mechanisms of cognitive impairment. PFC-thalamic anatomical connectivity may be an important target for procognitive interventions. Further work is needed to determine the implications of increased thalamic connectivity with sensory cortex. Copyright © 2017 Society of

  12. Animal models of cerebral ischemia

    Science.gov (United States)

    Khodanovich, M. Yu.; Kisel, A. A.

    2015-11-01

    Cerebral ischemia remains one of the most frequent causes of death and disability worldwide. Animal models are necessary to understand complex molecular mechanisms of brain damage as well as for the development of new therapies for stroke. This review considers a certain range of animal models of cerebral ischemia, including several types of focal and global ischemia. Since animal models vary in specificity for the human disease which they reproduce, the complexity of surgery, infarct size, reliability of reproduction for statistical analysis, and adequate models need to be chosen according to the aim of a study. The reproduction of a particular animal model needs to be evaluated using appropriate tools, including the behavioral assessment of injury and non-invasive and post-mortem control of brain damage. These problems also have been summarized in the review.

  13. Acute bowel ischemia: CT findings

    International Nuclear Information System (INIS)

    Angelelli, Giuseppe; Scardapane, Arnaldo; Memeo, Maurizio; Stabile Ianora, Amato Antonio; Rotondo, Antonio

    2004-01-01

    Acute bowel ischemia represents one of the most dramatic abdominal emergencies and, despite the fact it is more and more frequently observed in clinical practice, its mortality rate remains very high. In recent years Computed Tomography (CT) has proved to be a valid diagnostic tool in the evaluation of patients with acute abdominal syndrome and in the visualization of early signs of bowel ischemia. This paper reviews the aetiological and pathophysiological aspects as well as a broad spectrum of CT findings of this clinical condition

  14. Effects of standard ethanolic extract from Erythrina velutina in acute cerebral ischemia in mice.

    Science.gov (United States)

    Rodrigues, Francisca Taciana Sousa; de Sousa, Caren Nádia Soares; Ximenes, Naiara Coelho; Almeida, Anália Barbosa; Cabral, Lucas Moraes; Patrocínio, Cláudio Felipe Vasconcelos; Silva, Aline Holanda; Leal, Luzia Kalyne Almeida Moreira; Honório Júnior, José Eduardo Ribeiro; Macedo, Danielle; Vasconcelos, Silvânia Maria Mendes

    2017-12-01

    The objective of this study was to verify a possible neuroprotective effect of the ethanolic extract of Erythrina velutina (EEEV). Male Swiss mice were submitted to transient cerebral ischemia by occlusion of both carotid arteries for 30 min and treated for 5 days with EEEV (200 or 400 mg/kg) or Memantine (MEM) 10 mg/kg, with initiation of treatment 2 or 24 h after Ischemia. On the 6th day after the induction of ischemia, the animals were submitted to evaluation of locomotor activity and memory and then sacrificed. The brains were dissected for the removal of the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) for determination of amino acid concentrations. In the step down and Y-maze tests, ischemia caused damage to the animals and treatment with EEEV or MEM reversed this effect. The animals submitted to ischemia also showed memory deficit in the object recognition test, an effect that was reverted by EEEV400 and MEM10. Amino acid dosage showed an increase in excitatory amino acid concentrations in the PFC of the ischemic animals and this effect was reversed by the treatment with EEEV400/24H. Regarding the inhibitory amino acids, ischemia caused an increase of taurine in the PFC while treatment with MEM10/24H or EEEV400/24H reversed this effect. In HC, an increase in excitatory amino acids was also observed in ischemiated animals having treatment with EEEV200/2H or EEEV400/24H reversed this effect. Similar effect was also observed in the same area in relation to the inhibitory amino acids with treatment with MEM10/24H or EEEV400/24H. In the ST, ischemia was also able to cause an increase in excitatory amino acids that was reversed more efficiently by the treatments with MEM10/24H and EEEV200. Also in this area, an increase of taurine and GABA was observed and only the treatment with EEEV200/2H showed a reversion of this effect. In view of these findings, EEEV presents a neuroprotective effect possibly due to its action on amino acid

  15. Intralaminar and medial thalamic influence on cortical synchrony, information transmission and cognition

    Directory of Open Access Journals (Sweden)

    Yuri B Saalmann

    2014-05-01

    Full Text Available The intralaminar and medial thalamic nuclei are part of the higher-order thalamus, which receives little sensory input, and instead forms extensive cortico-thalamo-cortical pathways. The large mediodorsal thalamic nucleus predominantly connects with the prefrontal cortex, the adjacent intralaminar nuclei connect with fronto-parietal cortex, and the midline thalamic nuclei connect with medial prefrontal cortex and medial temporal lobe. Taking into account this connectivity pattern, it is not surprising that the intralaminar and medial thalamus has been implicated in a variety of cognitive functions, including memory processing, attention and orienting, as well as reward-based behavior. This review addresses how the intralaminar and medial thalamus may regulate information transmission in cortical circuits. A key neural mechanism may involve intralaminar and medial thalamic neurons modulating the degree of synchrony between different groups of cortical neurons according to behavioral demands. Such a thalamic-mediated synchronization mechanism may give rise to large-scale integration of information across multiple cortical circuits, consequently influencing the level of arousal and consciousness. Overall, the growing evidence supports a general role for the higher-order thalamus in the control of cortical information transmission and cognitive processing.

  16. Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury

    International Nuclear Information System (INIS)

    Wisnowski, Jessica L.; Ceschin, Rafael C.; Choi, So Young; Schmithorst, Vincent J.; Painter, Michael J.; Nelson, Marvin D.; Blueml, Stefan; Panigrahy, Ashok

    2015-01-01

    Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study. Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. (orig.)

  17. Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury

    Energy Technology Data Exchange (ETDEWEB)

    Wisnowski, Jessica L. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Ceschin, Rafael C. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Pittsburgh, Department of Biomedical Informatics, Pittsburgh, PA (United States); Choi, So Young [University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Schmithorst, Vincent J. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Painter, Michael J. [University of Pittsburgh, Department of Pediatrics, Division of Neurology, Childrens Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Nelson, Marvin D. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Blueml, Stefan [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Rudi Schulte Research Institute, Santa Barbara, CA (United States); Panigrahy, Ashok [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States)

    2015-05-01

    Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study. Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. (orig.)

  18. Thalamic diffusion differences related to cognitive function in white matter lesions.

    Science.gov (United States)

    Fernández-Andújar, Marina; Soriano-Raya, Juan José; Miralbell, Júlia; López-Cancio, Elena; Cáceres, Cynthia; Bargalló, Núria; Barrios, Maite; Arenillas, Juan Francisco; Toran, Pere; Alzamora, Maite; Clemente, Imma; Dávalos, Antoni; Mataró, Maria

    2014-05-01

    Cerebral white matter lesions (WMLs) are related to cognitive deficits, probably due to a disruption of frontal-subcortical circuits. We explored thalamic diffusion differences related to white matter lesions (WMLs) and their association with cognitive function in middle-aged individuals. Ninety-six participants from the Barcelona-AsIA Neuropsychology Study were included. Participants were classified into groups based on low grade and high grade of periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs). Tract-Based Spatial Statistics was used to study thalamic diffusion differences between groups. Mean fractional anisotropy (FA) values in significant areas were calculated for each subject and correlated with cognitive performance. Participants with high-grade PVHs and DWMHs showed lower FA thalamic values compared to those with low-grade PVHs and DWMHs, respectively. Decreased FA thalamic values in high-grade DWMHs, but not high-grade PVH, were related to lower levels of performance in psychomotor speed, verbal fluency, and visuospatial skills. Thalamic diffusion differences are related to lower cognitive function only in participants with high-grade DWMHs. These results support the hypothesis that fronto-subcortical disruption is associated with cognitive function only in DWMHs. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Characterization of in vivo MRI detectable thalamic amyloid plaques from APP/PS1 mice

    Energy Technology Data Exchange (ETDEWEB)

    Dhenain, M. [URA CEA CNRS 2210, I2BM, SHFJ, 4 Place du General Leclerc, 91401 Orsay Cedex (France); Dhenain, M.; El Tannir El Tayara, N.; Wu, T.D.; Volk, A.; Quintana, C. [U759 INSERM, Centre Universitaire, Laboratoire 112, 91405 Orsay Cedex (France); Dhenain, M.; El Tannir El Tayara, N.; Wu, T.D.; Volk, A.; Quintana, C. [Institut Curie, Centre Universitaire, Laboratoire 112, 91405 Orsay Cedex (France); Guegan, M.; Delatour, B. [Instituto de Microelectronica de Madrid-CSIC, 8, Isaac Newton, 28760 Tres Cantos, Madrid (Spain)

    2009-07-01

    Amyloid deposits are one of the hallmarks of Alzheimer's disease. Recent studies, in transgenic mice modeling Alzheimer's disease showed that, using in vivo, contrast agent-free, MRI, thalamic amyloid plaques are more easily detected than other plaques of the brain. Our study evaluated the characteristics of these thalamic plaques in a large population of APP/PS1, PS1 and C57BL/6 mice. Thalamic spots were detected in all mice but with different frequency and magnitude. Hence, the prevalence and size of the lesions were higher in APP/PS1 mice. However, even in APP/PS1 mice, thalamic spots did not occur in all the old animals. In APP/PS1 mice, spots detection was related to high iron and calcium load within amyloid plaques and thus reflects the ability of such plaque to capture large amounts of minerals. Interestingly, calcium and iron was also detected in extra-thalamic plaques but with a lower intensity. Hypointense lesions in the thalamus were not associated with the iron load in the tissue surrounding the plaques, nor with micro-hemorrhages, inflammation, or a neuro-degenerative context. (authors)

  20. Effect of Spinal Cord Stimulation on Gait in a Patient with Thalamic Pain

    Directory of Open Access Journals (Sweden)

    Arito Yozu

    2016-01-01

    Full Text Available Thalamic pain is a central neuropathic pain disorder which occurs after stroke. Its severe chronic pain is often intractable to pharmacotherapies and affects the patients’ activities of daily living (ADL and quality of life (QOL. Recently, spinal cord stimulation (SCS has been reported to be effective in relieving the pain of thalamic pain; however, the effect of SCS on gait performance in patients is unknown. Therefore, we evaluated the gait performance before and after SCS in a case with thalamic pain. A 73-year-old male with thalamic pain participated in this study. We evaluated the gait of the patient two times: before SCS insertion and after 6 days of SCS. At the second evaluation, we measured the gait in three conditions: stimulation off, comfortable stimulation, and strong stimulation. SCS succeeded in improving the pain from 7 to 2 on an 11-point numerical rating scale. Step frequency and the velocity of gait tended to increase between pre- and poststimulation periods. There were no apparent differences in gait among the three stimulation conditions (off, comfortable, and strong at the poststimulation period. SCS may be effective on gait in patients with thalamic pain.

  1. Differential impact of thalamic versus subthalamic deep brain stimulation on lexical processing.

    Science.gov (United States)

    Krugel, Lea K; Ehlen, Felicitas; Tiedt, Hannes O; Kühn, Andrea A; Klostermann, Fabian

    2014-10-01

    Roles of subcortical structures in language processing are vague, but, interestingly, basal ganglia and thalamic Deep Brain Stimulation can go along with reduced lexical capacities. To deepen the understanding of this impact, we assessed word processing as a function of thalamic versus subthalamic Deep Brain Stimulation. Ten essential tremor patients treated with thalamic and 14 Parkinson׳s disease patients with subthalamic Deep Brain Stimulation performed an acoustic Lexical Decision Task ON and OFF stimulation. Combined analysis of task performance and event-related potentials allowed the determination of processing speed, priming effects, and N400 as neurophysiological correlate of lexical stimulus processing. 12 age-matched healthy participants acted as control subjects. Thalamic Deep Brain Stimulation prolonged word decisions and reduced N400 potentials. No comparable ON-OFF effects were present in patients with subthalamic Deep Brain Stimulation. In the latter group of patients with Parkinson' disease, N400 amplitudes were, however, abnormally low, whether under active or inactive Deep Brain Stimulation. In conclusion, performance speed and N400 appear to be influenced by state functions, modulated by thalamic, but not subthalamic Deep Brain Stimulation, compatible with concepts of thalamo-cortical engagement in word processing. Clinically, these findings specify cognitive sequels of Deep Brain Stimulation in a target-specific way. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. IMAGE ANALYSIS IN GOMORI´S TRICHROME STAIN OF SKELETAL MUSCLES SUBJECTED TO ISCHEMIA AND REPERFUSION INJURY

    OpenAIRE

    Doris Haydee Rosero Salazar; Liliana Janeth Flórez Elvira

    2016-01-01

    Conditions that produce ischemia and reperfusion injury include orthopedic surgeries, vascular diseases and accidents in remote places in which use of a manual tourniquet is required. Tissues under such stress suffer the consequences of evidenced by changes in their normal microscopic organization that can be reversible or irreversible according to the time and severity of lesion. An experimental model of ischemia has been designed taking into account the characteristics similar to a surgical...

  3. Reverse Osmosis

    Indian Academy of Sciences (India)

    many applications, one of which is desalination of seawater. The inaugural Nobel Prize in Chemistry was awarded in 1901 to van 't Hoff for his seminal work in this area. The present article explains the principle of osmosis and reverse osmosis. Osmosis and Reverse Osmosis. As the name suggests, reverse osmosis is the ...

  4. Thalamic control of human attention driven by memory and learning.

    Science.gov (United States)

    de Bourbon-Teles, José; Bentley, Paul; Koshino, Saori; Shah, Kushal; Dutta, Agneish; Malhotra, Paresh; Egner, Tobias; Husain, Masud; Soto, David

    2014-05-05

    The role of the thalamus in high-level cognition-attention, working memory (WM), rule-based learning, and decision making-remains poorly understood, especially in comparison to that of cortical frontoparietal networks [1-3]. Studies of visual thalamus have revealed important roles for pulvinar and lateral geniculate nucleus in visuospatial perception and attention [4-10] and for mediodorsal thalamus in oculomotor control [11]. Ventrolateral thalamus contains subdivisions devoted to action control as part of a circuit involving the basal ganglia [12, 13] and motor, premotor, and prefrontal cortices [14], whereas anterior thalamus forms a memory network in connection with the hippocampus [15]. This connectivity profile suggests that ventrolateral and anterior thalamus may represent a nexus between mnemonic and control functions, such as action or attentional selection. Here, we characterize the role of thalamus in the interplay between memory and visual attention. We show that ventrolateral lesions impair the influence of WM representations on attentional deployment. A subsequent fMRI study in healthy volunteers demonstrates involvement of ventrolateral and, notably, anterior thalamus in biasing attention through WM contents. To further characterize the memory types used by the thalamus to bias attention, we performed a second fMRI study that involved learning of stimulus-stimulus associations and their retrieval from long-term memory to optimize attention in search. Responses in ventrolateral and anterior thalamic nuclei tracked learning of the predictiveness of these abstract associations and their use in directing attention. These findings demonstrate a key role for human thalamus in higher-level cognition, notably, in mnemonic biasing of attention. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Experimental mesenteric ischemia. Radioisotopic diagnosis

    International Nuclear Information System (INIS)

    Alberti, Carlos; Dallaglio, Juan; Sarra, Luis; Obiols, Eugenio; Rodriguez Santos, Emilio; Delgado, Eduardo; Castelleti, Luis

    1995-01-01

    A non-invasive radionuclide technique with 99-Tc-DMP for the early diagnosis of small bowel infarction due to mesenteric artery compression, was evaluated. The usefulness of 99-Tc-DMP and critical pressure of mesenteric artery were demonstrated. The diagnosis was performed before one hour had passed from the beginning of the ischemia

  6. Accelerated forgetting of contextual details due to focal medio-dorsal thalamic lesion

    Directory of Open Access Journals (Sweden)

    Sicong eTu

    2014-09-01

    Full Text Available Effects of thalamic nuclei damage and related white matter tracts on memory performance are still debated. This is particularly evident for the medio-dorsal thalamus which has been less clear in predicting amnesia than anterior thalamus changes. The current study addresses this issue by assessing 7 thalamic stroke patients with consistent unilateral lesions focal to the left medio-dorsal nuclei for immediate and delayed memory performance on standard visual and verbal tests of anterograde memory, and over the long-term (> 24 hrs on an object-location associative memory task. Thalamic patients showed selective impairment to delayed recall, but intact recognition memory. Patients also showed accelerated forgetting of contextual information after a 24 hour delay, compared to controls. Importantly, the mammillothalamic tract was intact in all patients, which suggests a role for the medio-dorsal nuclei in recall and early consolidation memory processes.

  7. Cerebellar Ataxia from Multiple Potential Causes: Hypothyroidism, Hashimoto's Thyroiditis, Thalamic Stimulation, and Essential Tremor

    Directory of Open Access Journals (Sweden)

    Natalya V. Shneyder

    2012-04-01

    Full Text Available Background: Both hypothyroidism and Hashimoto's thyroiditis (HT can rarely be associated with cerebellar ataxia. Severe essential tremor (ET as well as bilateral thalamic deep brain stimulation (DBS may lead to subtle cerebellar signs. Case Report: We report a 74-year-old male with hypothyroidism and a 20-year history of ET who developed cerebellar ataxia after bilateral thalamic DBS. Extensive workup revealed elevated thyroid stimulating hormone and thyroperoxidase antibody titers confirming the diagnosis of HT. Discussion: Our case demonstrates multiple possible causes of cerebellar ataxia in a patient, including hypothyroidism, HT, chronic ET, and bilateral thalamic DBS. Counseling of patients may be appropriate when multiple risk factors for cerebellar ataxia coexist in one individual.

  8. Frontotemporal dementia with severe thalamic involvement : a clinical and neuropathological study

    Directory of Open Access Journals (Sweden)

    Radanovic Márcia

    2003-01-01

    Full Text Available Frontotemporal dementia (FTD is the third-leading cause of cortical dementia after Alzheimer's disease and Lewy body dementia, and is characterized by a dementia where behavioral disturbances are prominent and appear early in the course of the disease. We report the case of a 58 year-old man affected by dementia with behavioral disturbances, in addition to rigid-hypokinetic and a lower motor neuron syndrome that were present at later stages of the illness. Neuroimaging studies showed frontotemporal atrophy. Neuropathological studies revealed intense thalamic neuronal loss and astrocytic gliosis, as well as moderate frontotemporal neuronal loss, astrocytosis and spongiform degeneration. Thalamic degeneration has previously been described among the wide group of neuropathological features of FTD. The aim of the present study is to show the clinical and neuropathological aspects of thalamic degeneration in FTD, along with its role in behavioral disturbances, a common finding in this condition.

  9. The Effect of Thalamic Stimulation on Memory and Language Processing in Parkinsonian Patients

    Directory of Open Access Journals (Sweden)

    Zahrasadat Ghoreishi

    2006-01-01

    Full Text Available Objective: Thalamic Deep Brain Stimulation (DBS is reported to be successful in Parkinson patients with motor symptoms resistant to medication as a treatment procedure. Despite evidence of cortico-subcortico-cortical circuit involvement in motor control, the role of this neural circuitry on higher cognitive functions such as language is still controversial. In particular, research evidence pertaining to the impact of ventrolateral thalamic stimulation on linguistic processing is scarce. This paper investigates the effect of right and left thalamus-DBS on memory and language processing in Parkinson patients. Materials & Methods: In this paper as a case series research we measured memory and language processing in six Parkinson patients (2 left, 2right, 2 bilateral underwent implantation of deep brain stimulating electrode in ventrolateral thalamic nucleus. The data were collected in two “on” and “off” positions, with at least 40 days time interval in between. The patients were assessed using Wechsler memory test, verbal fluency and some sub-tests of Farsi version of Bilingual Aphasia Test (BAT. Results: The findings of this research are suggesting an improvement on grammar comprehension and a decline in sentence production and verbal fluency in “on” position versus “off” position, in both groups. The Wechsler memory scores in left thalamus group improved but declined in right thalamus group. Conclusion: The results indicate that thalamic DBS did not cause any deficit on grammar comprehension and even improved the level of comprehension. On the contrary a decrease in verbal fluency and sentence production, as two high level linguistic processing tasks, was observed. The results confirmed contemporary theories of thalamic participation on language processing and did not confirm a laterality effect on language skills. Although observed difference after thalamic DBS between right and left group on memory score can confirm laterality

  10. Impairments of thalamic resting-state functional connectivity in patients with chronic tinnitus

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    Zhang, Jian [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Chen, Yu-Chen [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Center for Hearing and Deafness, University at Buffalo, State University of New York, Buffalo, NY (United States); Feng, Xu [Department of Otolaryngology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Yang, Ming; Liu, Bin; Qian, Cheng [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China); Wang, Jian [Department of Physiology, Southeast University, Nanjing (China); School of Human Communication Disorders, Dalhousie University, Halifax, NS (Canada); Salvi, Richard [Center for Hearing and Deafness, University at Buffalo, State University of New York, Buffalo, NY (United States); Teng, Gao-Jun, E-mail: gjteng@vip.sina.com [Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing (China)

    2015-07-15

    Highlights: • Tinnitus patients have aberrant thalamic connectivity to many brain regions. • Decreased thalamic connectivity is linked with tinnitus characteristics. • Thalamocortical connectivity disturbances can reflect tinnitus-related networks. - Abstract: Purpose: The phantom sound of tinnitus is believed to arise from abnormal functional coupling between the thalamus and cerebral cortex. To explore this hypothesis, we used resting-state functional magnetic resonance imaging (fMRI) to compare the degree of thalamocortical functional connectivity in chronic tinnitus patients and controls. Materials and methods: Resting-state fMRI scans were obtained from 31 chronic tinnitus patients and 33 well-matched healthy controls. Thalamocortical functional connectivity was characterized using a seed-based whole-brain correlation method. The resulting thalamic functional connectivity measures were correlated with other clinical data. Results: We found decreased functional connectivity between the seed region in left thalamus and right middle temporal gyrus (MTG), right middle orbitofrontal cortex, left middle frontal gyrus, right precentral gyrus, and bilateral calcarine cortex. Decreased functional connectivity was detected between the seed in the right thalamus and the left superior temporal gyrus (STG), left amygdala, right superior frontal gyrus, left precentral gyrus, and left middle occipital gyrus. Tinnitus distress correlated negatively with thalamic functional connectivity in right MTG; tinnitus duration correlated negatively with thalamic functional connectivity in left STG. Increased functional connectivity between the bilateral thalamus and a set of regions were also observed. Conclusions: Chronic tinnitus patients have disrupted thalamocortical functional connectivity to selected brain regions which is associated with specific tinnitus characteristics. Resting-state thalamic functional connectivity disturbances may play an important role in

  11. Dissociation of Recognition and Recency Memory Judgments After Anterior Thalamic Nuclei Lesions in Rats

    Science.gov (United States)

    Dumont, Julie R.; Aggleton, John P.

    2013-01-01

    The anterior thalamic nuclei form part of a network for episodic memory in humans. The importance of these nuclei for recognition and recency judgments remains, however, unclear. Rats with anterior thalamic nuclei lesions and their controls were tested on object recognition, along with two types of recency judgment. The spontaneous discrimination of a novel object or a novel odor from a familiar counterpart (recognition memory) was not affected by anterior thalamic lesions when tested after retention delays of 1 and 60 min. To measure recency memory, rats were shown two familiar objects, one of which had been explored more recently. In one condition, rats were presented with two lists (List A, List B) of objects separated by a delay, thereby creating two distinct blocks of stimuli. After an additional delay, rats were presented with pairs of objects, one from List A and one from List B (between-block recency). No lesion-induced deficit was apparent for recency discriminations between objects from different lists, despite using three different levels of task difficulty. In contrast, rats with anterior thalamic lesions were significantly impaired when presented with a continuous list of objects and then tested on their ability to distinguish between those items early and late in the same list (within-block recency). The contrasting effects on recognition and recency support the notion that interlinked hippocampal–anterior thalamic interconnections support aspects of both spatial and nonspatial learning, although the role of the anterior thalamic nuclei may be restricted to a subclass of recency judgments (within-block). PMID:23731076

  12. Neonatal thalamic hemorrhage is strongly associated with electrical status epilepticus in slow wave sleep.

    Science.gov (United States)

    Kersbergen, Karina J; de Vries, Linda S; Leijten, Frans S S; Braun, Kees P J; Nievelstein, Rutger A J; Groenendaal, Floris; Benders, Manon J N L; Jansen, Floor E

    2013-04-01

    Thalamic hemorrhage has been associated with neonatal cerebral sinovenous thrombosis (CSVT), especially when the straight sinus is involved, and often presents with neonatal seizures. Early thalamic injury has previously been shown to predispose to epilepsy and electrical status epilepticus in slow wave sleep (ESES). The objective of this study was to assess the prevalence of sleep-induced epileptic electroencephalography (EEG) abnormalities and postneonatal epilepsy after neonatal thalamic hemorrhage associated with CSVT, in the absence of more widespread cerebral damage. Between 2003 and 2008 15 neonates were diagnosed with a thalamic hemorrhage due to suspected or proven CSVT. Neurodevelopment and the history of seizures were assessed at follow-up in the outpatient clinic in all 14 survivors (age 2-9 years). Whole-night or sleep-deprived EEG recordings were obtained to assess the prevalence of interictal epileptiform activity (EA) and calculate a sleep-induced spike and wave index (SWI). Three children were diagnosed with classic ESES (SWI >85%). Two children had ESES spectrum disorder (SWI between 50% and 85%), and in two children significant sleep-induced epileptiform activity (SIEA) was noted (SWI between 25% and 50%). Two other children were diagnosed with focal epilepsy, in the absence of sleep-induced epileptiform EEG abnormalities. Five children (age 2-7 years) had normal EEG recordings at follow-up. Deficits in neurodevelopment were seen significantly more often in children with ESES, ESES spectrum, or SIEA. Neonates with thalamic hemorrhage associated with straight sinus thrombosis, without evidence of more widespread cerebral damage, are at high risk of developing ESES (spectrum) disorder (35%), SIEA (14%), or focal epilepsy (14%). Electrographic abnormalities may already be present prior to recognition of cognitive deficits. Early diagnosis may guide parents and caregivers, and subsequent treatment may improve neurodevelopmental outcome. Routine

  13. Impairments of thalamic resting-state functional connectivity in patients with chronic tinnitus

    International Nuclear Information System (INIS)

    Zhang, Jian; Chen, Yu-Chen; Feng, Xu; Yang, Ming; Liu, Bin; Qian, Cheng; Wang, Jian; Salvi, Richard; Teng, Gao-Jun

    2015-01-01

    Highlights: • Tinnitus patients have aberrant thalamic connectivity to many brain regions. • Decreased thalamic connectivity is linked with tinnitus characteristics. • Thalamocortical connectivity disturbances can reflect tinnitus-related networks. - Abstract: Purpose: The phantom sound of tinnitus is believed to arise from abnormal functional coupling between the thalamus and cerebral cortex. To explore this hypothesis, we used resting-state functional magnetic resonance imaging (fMRI) to compare the degree of thalamocortical functional connectivity in chronic tinnitus patients and controls. Materials and methods: Resting-state fMRI scans were obtained from 31 chronic tinnitus patients and 33 well-matched healthy controls. Thalamocortical functional connectivity was characterized using a seed-based whole-brain correlation method. The resulting thalamic functional connectivity measures were correlated with other clinical data. Results: We found decreased functional connectivity between the seed region in left thalamus and right middle temporal gyrus (MTG), right middle orbitofrontal cortex, left middle frontal gyrus, right precentral gyrus, and bilateral calcarine cortex. Decreased functional connectivity was detected between the seed in the right thalamus and the left superior temporal gyrus (STG), left amygdala, right superior frontal gyrus, left precentral gyrus, and left middle occipital gyrus. Tinnitus distress correlated negatively with thalamic functional connectivity in right MTG; tinnitus duration correlated negatively with thalamic functional connectivity in left STG. Increased functional connectivity between the bilateral thalamus and a set of regions were also observed. Conclusions: Chronic tinnitus patients have disrupted thalamocortical functional connectivity to selected brain regions which is associated with specific tinnitus characteristics. Resting-state thalamic functional connectivity disturbances may play an important role in

  14. Lucid dreams, an atypical sleep disturbance in anterior and mediodorsal thalamic strokes.

    Science.gov (United States)

    Sagnier, S; Coulon, P; Chaufton, C; Poli, M; Debruxelles, S; Renou, P; Rouanet, F; Olindo, S; Sibon, I

    2015-11-01

    Cognitive, affective, and behavioural disturbances are commonly reported following thalamic strokes. Conversely, sleep disorders are rarely reported in this context. Herein, we report the cases of two young patients admitted for an ischemic stroke located in the territories of the left pre-mammillary and paramedian arteries. Together with aphasia, memory complaint, impaired attention and executive functions, they reported lucid dreams with catastrophic content or conflicting situations. Lucid dreams are an atypical presentation in thalamic strokes. These cases enlarge the clinical spectrum of sleep-wake disturbances potentially observed after an acute cerebrovascular event. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. The administration of renoprotective agents extends warm ischemia in a rat model.

    Science.gov (United States)

    Cohen, Jacob; Dorai, Thambi; Ding, Cheng; Batinic-Haberle, Ines; Grasso, Michael

    2013-03-01

    Extended warm ischemia time during partial nephrectomy leads to considerable renal injury. Using a rat model of renal ischemia, we examined the ability of a unique renoprotective cocktail to ameliorate warm ischemia-reperfusion injury and extend warm ischemia time. A warm renal ischemia model was developed using Sprague-Dawley rats, clamping the left renal artery for 40, 50, 60, and 70 minutes, followed by 48 hours of reperfusion. An improved renoprotective cocktail referred to as I-GPM (a mixture of specific renoprotective growth factors, porphyrins, and mitochondria-protecting amino acids) was administered -24 hours, 0 hours, and +24 hours after surgery. At 48 hours, both kidneys were harvested and examined with hematoxylin and eosin and periodic acid-Schiff stains for the analysis of renal tubular necrosis. Creatinine, protein, and gene expression levels were also analyzed to evaluate several ischemia-specific and antioxidant response markers. I-GPM treated kidneys showed significant reversal of morphologic changes and a significant reduction in specific ischemic markers lipocalin-2, galectin-3, GRP-78, and HMGB1 compared with ischemic controls. These experiments also showed an upregulation of the stress response protein, heat shock protein (HSP)-70, as well as the phosphorylated active form of the transcription factor, heat shock factor (HSF)-1. In addition, quantitative RT-PCR analyses revealed a robust upregulation of several antioxidant pathway response genes in I-GPM treated animals. By histopathologic and several molecular measures, our unique renoprotective cocktail mitigated ischemia-reperfusion injury. Our cocktail minimized oxidative stress in an ischemic kidney rat model while at the same time protecting the global parenchymal function during extended periods of ischemia.

  16. Evaluation of the Efficacy of Treatment of Newborns with Transient Myocardial Ischemia

    Directory of Open Access Journals (Sweden)

    Yulia N. Dovnar

    2018-01-01

    Full Text Available The purpose of the study: a comprehensive assessment of the effectiveness of the treatment of newborns with transient myocardial ischemia in the intensive care unit.Materials and methods. 102 newborns with transient myocardial ischemia, with a history of ante- and/or intranatal hypoxia, at the age of 1 to 7 days, with a gestational age from 29 to 42 weeks, underwent a clinical and instrumental examination of the heart before and during the treatment. The Group 1 consisted of 30 infants with 1 degree circulatory failure (CF; the Group 2 was comprised of 39 infants with 2A degree of CF, and the Group 3 included 33 infants with the 2B degree of CF. All children received cardiotropic drugs; infants from Groups 2 and 3 received cardiotonic drugs.Results. The study demonstrated an increase in biochemical parameters of blood (myocardial CPK, lactate dehydrogenase, aspartate aminotransferase, de Ritis ratio, manifestations of subendocardial ischemia in the electrocardiogram (depression of ST segment in one or more leads in combination with a T-wave defect, changes in systolic cardiac function during echocardiography (stroke volume, ejection and shortening factions, left ventricular TEI index, cardiac output, and cardiac index that correlated with the severity of myocardial ischemia and circulatory failure and their reverse development during the treatment. Various correlative links between parameters of left ventricular systolic function and blood biochemistry before and during the treatment reflecting the myocardial dysfunction with a gradual reverse development have been found.Conclusion. Infants with transient myocardial ischemia suffered from disorders of the clinical and functional state of the heart depending on the degree of ischemia and circulatory failure. Most infants exebited gradual reverse development during a complex intensive therapy. 

  17. Functional tests for myocardial ischemia

    International Nuclear Information System (INIS)

    Levinson, J.R.; Guiney, T.E.; Boucher, C.A.

    1991-01-01

    Functional tests for myocardial ischemia are numerous. Most depend upon a combination of either exercise or pharmacologic intervention with analysis of the electrocardiogram, of regional perfusion with radionuclide imaging, or of regional wall motion with radionuclide imaging or echocardiography. While each test has unique features, especially at the research level, they are generally quite similar in clinical practice, so the clinician is advised to concentrate on one or two in which local expertise is high.22 references

  18. Myocardial ischemia in Kawasaki disease

    International Nuclear Information System (INIS)

    Fukuda, Tsuyoshi

    1993-01-01

    The detection of myocardial ischemia is essential for evaluation of patients with Kawasaki disease, especially who have had coronary artery lesions. To evaluate the clinical efficacy of Tl-201 single photon emission computed tomography (SPECT) after dipyridamole infusion (maximum dose 0.70 mg/kg) for detecting myocardial ischemia, 44 patients with Kawasaki disease aged 7.7±4.8 years at the study and 10 age matched controls were observed. In the Kawasaki disease group, significant coronary artery stenosis was observed in 14, coronary aneurysm without stenosis in 18, the regression of the coronary aneurysms in 2 and without coronary lesions in 10 patients. In 24 of 44 patients, treadmill exercise stress test was also performed at the same period. Myocardial ischemic changes were observed in 11 patients, all combined with significant coronary artery stenosis. The sensitivity of SPECT for detection of overall coronary stenosis was 79%, coronary that of treadmill exercise test was only 33% (p<0.001). Furthermore, among the patients having significant coronary stenosis, the severity score was significantly elevated in patients who had electrocardiographic abnormal Q wave compared to those without abnormal Q wave (51.0±38.8 versus 20.0±12.1, p<0.05). These data suggest that the pharmacological stress scintigraphy using dipyridamole injection provides not only the accurate detection but quantitative evaluation of myocardial ischemia in these patients. This noninvasive technique may become one of the most useful index for detection and follow-up of myocardial ischemia in Kawasaki disease. (author)

  19. Multicentre European study of thalamic stimulation for parkinsonian tremor: a 6 year follow-up

    NARCIS (Netherlands)

    Hariz, M. I.; Krack, P.; Alesch, F.; Augustinsson, L.-E.; Bosch, A.; Ekberg, R.; Johansson, F.; Johnels, B.; Meyerson, B. A.; N'Guyen, J.-P.; Pinter, M.; Pollak, P.; von Raison, F.; Rehncrona, S.; Speelman, J. D.; Sydow, O.; Benabid, A.-L.

    2008-01-01

    To evaluate the results of ventral intermediate (Vim) thalamic deep brain stimulation (DBS) in patients with tremor predominant Parkinson's disease (PD) at 6 years post surgery. This was a prolonged follow-up study of 38 patients from eight centres who participated in a multicentre study, the 1 year

  20. A case of thalamic hemorrhage presenting high density on CT in a long time

    International Nuclear Information System (INIS)

    Hosoya, Takaaki; Takeda, Yoshio; Sugai, Yukio; Umetsu, Akemi; Yamaguchi, Koichi

    1988-01-01

    We presented a thalamic hemorrhage in a 29-year-old woman with idiopathic thrombocytopenic purpura during pregnancy showing a high density lesion at least for 50 days on CT. From beginning of the illness, this condition was considered to continue for 3 months by chronic bleeding or recurrent hemorrhage. (author)

  1. Aphasia and unilateral spatial neglect due to acute thalamic hemorrhage: clinical correlations and outcomes.

    Science.gov (United States)

    Osawa, Aiko; Maeshima, Shinichiro

    2016-04-01

    Thalamic hemorrhages are associated with a variety of cognitive dysfunctions, and it is well known that such cognitive changes constitute a limiting factor of recovery of the activities of daily living (ADL). The relationship between cognitive dysfunction and hematomas is unclear. In this study, we investigated the relationship between aphasia/neglect and hematoma volume, hematoma type, and the ADL. One hundred fifteen patients with thalamic hemorrhage (70 men and 45 women) were studied. Their mean age was 68.9 ± 10.3 years, and patients with both left and right lesions were included. We calculated hematoma volume and examined the presence or absence of aphasia/neglect and the relationships between these dysfunctions and hematoma volume, hematoma type, and the ADL. Fifty-nine patients were found to have aphasia and 35 were found to have neglect. Although there was no relationship between hematoma type and cognitive dysfunction, hematoma volume showed a correlation with the severity of cognitive dysfunction. The ADL score and ratio of patient discharge for patients with aphasia/neglect were lower than those for patients without aphasia/neglect. We observed a correlation between the hematoma volume in thalamic hemorrhage and cognitive dysfunction. Aphasia/neglect is found frequently in patients with acute thalamic hemorrhage and may influence the ADL.

  2. Distinct molecular components for thalamic- and cortical-dependent plasticity in the lateral amygdala.

    Science.gov (United States)

    Mirante, Osvaldo; Brandalise, Federico; Bohacek, Johannes; Mansuy, Isabelle M

    2014-01-01

    N-methyl-D-aspartate receptor (NMDAR)-dependent long-term depression (LTD) in the lateral nucleus of the amygdala (LA) is a form of synaptic plasticity thought to be a cellular substrate for the extinction of fear memory. The LA receives converging inputs from the sensory thalamus and neocortex that are weakened following fear extinction. Combining field and patch-clamp electrophysiological recordings in mice, we show that paired-pulse low-frequency stimulation can induce a robust LTD at thalamic and cortical inputs to LA, and we identify different underlying molecular components at these pathways. We show that while LTD depends on NMDARs and activation of the protein phosphatases PP2B and PP1 at both pathways, it requires NR2B-containing NMDARs at the thalamic pathway, but NR2C/D-containing NMDARs at the cortical pathway. LTD appears to be induced post-synaptically at the thalamic input but presynaptically at the cortical input, since post-synaptic calcium chelation and NMDAR blockade prevent thalamic but not cortical LTD. These results highlight distinct molecular features of LTD in LA that may be relevant for traumatic memory and its erasure, and for pathologies such as post-traumatic stress disorder (PTSD).

  3. Schizophrenia; from structure to function with special focus on the mediodorsal thalamic prefrontal loop

    DEFF Research Database (Denmark)

    Pakkenberg, B.; Scheel-Kruger, J.; Kristiansen, L.V.

    2009-01-01

    studies in postmortem brain from patients with schizophrenia have reported divergent and often opposing findings in the total number of neurons and volume of the mediodorsal (MD) thalamic nucleus, and to a lesser degree in its reciprocally associated areas of the prefrontal cortex. Similarly, quantitative...

  4. Distinct molecular components for thalamic- and cortical-dependent plasticity in the lateral amygdala

    Directory of Open Access Journals (Sweden)

    Osvaldo eMirante

    2014-07-01

    Full Text Available N-methyl-D-aspartate receptor (NMDAR-dependent long-term depression (LTD in the lateral nucleus of the amygdala (LA is a form of synaptic plasticity thought to be a cellular substrate for the extinction of fear memory. The LA receives converging inputs from the sensory thalamus and neocortex that are weakened following fear extinction. Combining field and patch-clamp electrophysiological recordings in mice, we show that a paired-pulse low-frequency stimulation can induce a robust LTD at thalamic and cortical inputs to LA, and we identify different underlying molecular components at these pathways. We show that while LTD depends on NMDARs and activation of the protein phosphatases PP2B and PP1 at both pathways, it requires NR2B-containing NMDARs at the thalamic pathway, but NR2C/D-containing NMDARs at the cortical pathway. LTD appears to be induced postsynaptically at the thalamic input but presynaptically at the cortical input, since postsynaptic calcium chelation and NMDAR blockade prevent thalamic but not cortical LTD. These results highlight distinct molecular features of LTD in LA that may be relevant for traumatic memory and its erasure, and for pathologies such as post-traumatic stress disorder (PTSD.

  5. Acute Korsakoff-like amnestic syndrome resulting from left thalamic infarction following a right hippocampal hemorrhage.

    Science.gov (United States)

    Rahme, R; Moussa, R; Awada, A; Ibrahim, I; Ali, Y; Maarrawi, J; Rizk, T; Nohra, G; Okais, N; Samaha, E

    2007-04-01

    Korsakoff-like amnestic syndromes have been rarely described following structural lesions of the central nervous system. In this report, we describe a case of acute Korsakoff-like syndrome resulting from the combination of a left anteromedian thalamic infarct and a right hippocampal hemorrhage. We also review the literature relevant to the neuropathology and pathophysiology of Korsakoff syndrome and anterograde amnesia.

  6. Complex neurological symptoms in bilateral thalamic stroke due to Percheron artery occlusion.

    Science.gov (United States)

    Caruso, Paola; Manganotti, Paolo; Moretti, Rita

    2017-01-01

    The artery of Percheron is a rare anatomical variant where a single thalamic perforating artery arises from the proximal posterior cerebral artery (P1 segment) between the basilar artery and the posterior communicating artery and supplies the rostral mesencephalon and both paramedian territories of the thalami. Almost one-third of human brains present this variant. Occlusion of the artery of Percheron mostly results in a bilateral medial thalamic infarction, which usually manifests with altered consciousness (including coma), vertical gaze paresis, and cognitive disturbance. The presentation is similar to the "top of the basilar syndrome", and early recognition should be prompted. We describe the case of a young female with this vessel variant who experienced a bilateral thalamic stroke. Magnetic resonance angiography demonstrated bilateral thalamic infarcts and a truncated artery of Percheron. Occlusion of the vessel was presumably due to embolism from a patent foramen ovale. Thrombolysis was performed, with incomplete symptom remission, cognitive impairment, and persistence of speech disorders. Early recognition and treatment of posterior circulation strokes is mandatory, and further investigation for underlying stroke etiologies is needed.

  7. A stereological study of the mediodorsal thalamic nucleus in Down syndrome

    DEFF Research Database (Denmark)

    Karlsen, A S; Korbo, S; Uylings, H B M

    2014-01-01

    The total number of neurons and glial cells in the mediodorsal thalamic (MDT) nucleus of four aged females with Down syndrome (DS; mean age 69years) was estimated and compared to six age- and sex-matched controls. The MDT nucleus was delineated on coronal sections, and cell numbers (large and small...

  8. Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

    International Nuclear Information System (INIS)

    Qi, Rongfeng; Zhang, Long Jiang; Zhong, Jianhui; Zhang, Zhiqiang; Ni, Ling; Zheng, Gang; Lu, Guang Ming

    2013-01-01

    Background and purpose: Little is known about the role of thalamus in the pathophysiology of minimal hepatic encephalopathy (MHE). The purpose of this study was to investigate whether the thalamic functional connectivity was disrupted in cirrhotic patients with MHE by using resting-state functional magnetic resonance imaging (rs-fMRI). Materials and Methods: Twenty seven MHE patients and twenty seven age- and gender- matched healthy controls participated in the rs-fMRI scans. The functional connectivity of 11 thalamic nuclei were characterized by using a standard seed-based whole-brain correlation method and compared between MHE patients and healthy controls. Pearson correlation analysis was performed between the thalamic functional connectivity and venous blood ammonia levels/neuropsychological tests scores of patients. Results: The ventral anterior nucleus (VAN) and the ventral posterior medial nucleus (VPMN) in each side of thalamus showed abnormal functional connectivities in MHE. Compared with healthy controls, MHE patients demonstrated significant decreased functional connectivity between the right/left VAN and the bilateral putamen/pallidum, inferior frontal gyri, insula, supplementary motor area, right middle frontal gyrus, medial frontal gyrus. In addition, MHE patients showed significantly decreased functional connectivity with the right/left VPMN in the bilateral middle temporal gyri (MTG), temporal lobe, and right superior temporal gyrus. The venous blood ammonia levels of MHE patients negatively correlated with the functional connectivity between the VAN and the insula. Number connecting test scores showed negative correlation with the functional connectivity between the VAN and the insula, and between the VPMN and the MTG. Conclusion: MHE patients had disrupted thalamic functional connectivity, which mainly located in the bilateral ventral anterior nuclei and ventral posterior medial nuclei. The decreased connectivity between thalamus and many

  9. Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Rongfeng [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Zhang, Long Jiang, E-mail: kevinzhanglongjiang@yahoo.com.cn [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Zhong, Jianhui [Department of Biomedical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, Zhiqiang; Ni, Ling; Zheng, Gang [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Lu, Guang Ming, E-mail: cjr.luguangming@vip.163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China)

    2013-05-15

    Background and purpose: Little is known about the role of thalamus in the pathophysiology of minimal hepatic encephalopathy (MHE). The purpose of this study was to investigate whether the thalamic functional connectivity was disrupted in cirrhotic patients with MHE by using resting-state functional magnetic resonance imaging (rs-fMRI). Materials and Methods: Twenty seven MHE patients and twenty seven age- and gender- matched healthy controls participated in the rs-fMRI scans. The functional connectivity of 11 thalamic nuclei were characterized by using a standard seed-based whole-brain correlation method and compared between MHE patients and healthy controls. Pearson correlation analysis was performed between the thalamic functional connectivity and venous blood ammonia levels/neuropsychological tests scores of patients. Results: The ventral anterior nucleus (VAN) and the ventral posterior medial nucleus (VPMN) in each side of thalamus showed abnormal functional connectivities in MHE. Compared with healthy controls, MHE patients demonstrated significant decreased functional connectivity between the right/left VAN and the bilateral putamen/pallidum, inferior frontal gyri, insula, supplementary motor area, right middle frontal gyrus, medial frontal gyrus. In addition, MHE patients showed significantly decreased functional connectivity with the right/left VPMN in the bilateral middle temporal gyri (MTG), temporal lobe, and right superior temporal gyrus. The venous blood ammonia levels of MHE patients negatively correlated with the functional connectivity between the VAN and the insula. Number connecting test scores showed negative correlation with the functional connectivity between the VAN and the insula, and between the VPMN and the MTG. Conclusion: MHE patients had disrupted thalamic functional connectivity, which mainly located in the bilateral ventral anterior nuclei and ventral posterior medial nuclei. The decreased connectivity between thalamus and many

  10. Flexible Use of Predictive Cues beyond the Orbitofrontal Cortex: Role of the Submedius Thalamic Nucleus.

    Science.gov (United States)

    Alcaraz, Fabien; Marchand, Alain R; Vidal, Elisa; Guillou, Alexandre; Faugère, Angélique; Coutureau, Etienne; Wolff, Mathieu

    2015-09-23

    The orbitofrontal cortex (OFC) is known to play a crucial role in learning the consequences of specific events. However, the contribution of OFC thalamic inputs to these processes is largely unknown. Using a tract-tracing approach, we first demonstrated that the submedius nucleus (Sub) shares extensive reciprocal connections with the OFC. We then compared the effects of excitotoxic lesions of the Sub or the OFC on the ability of rats to use outcome identity to direct responding. We found that neither OFC nor Sub lesions interfered with the basic differential outcomes effect. However, more specific tests revealed that OFC rats, but not Sub rats, were disproportionally relying on the outcome, rather than on the discriminative stimulus, to guide behavior, which is consistent with the view that the OFC integrates information about predictive cues. In subsequent experiments using a Pavlovian contingency degradation procedure, we found that both OFC and Sub lesions produced a severe deficit in the ability to update Pavlovian associations. Altogether, the submedius therefore appears as a functionally relevant thalamic component in a circuit dedicated to the integration of predictive cues to guide behavior, previously conceived as essentially dependent on orbitofrontal functions. Significance statement: In the present study, we identify a largely unknown thalamic region, the submedius nucleus, as a new functionally relevant component in a circuit supporting the flexible use of predictive cues. Such abilities were previously conceived as largely dependent on the orbitofrontal cortex. Interestingly, this echoes recent findings in the field showing, in research involving an instrumental setup, an additional involvement of another thalamic nuclei, the parafascicular nucleus, when correct responding requires an element of flexibility (Bradfield et al., 2013a). Therefore, the present contribution supports the emerging view that limbic thalamic nuclei may contribute critically to

  11. Transient mitral regurgitation: An adjunctive sign of myocardial ischemia during dipyridamole-thallium imaging

    International Nuclear Information System (INIS)

    Lette, J.; Gagnon, A.; Lapointe, J.; Cerino, M.

    1989-01-01

    A patient developed transient exacerbation of a mitral insufficiency murmur and a reversible posterior wall perfusion defect during dipyridamole-thallium imaging. Coronary angiography showed significant stenoses of both the right and the circumflex coronary arteries that supply the posterior papillary muscle. Cardiac auscultation for transient mitral incompetence, a sign of reversible papillary muscle dysfunction, is a simple and practical adjunctive test for myocardial ischemia during dipyridamole-thallium imaging. It may confirm that an isolated reversible posterior wall myocardial perfusion defect is truly ischemic in nature as opposed to an artifact resulting from attenuation by the diaphragm

  12. [Effects of the of renal warm ischemia time on the recovery of filtration function in the experiment].

    Science.gov (United States)

    Guseinov, R G; Popov, S V; Gorshkov, A N; Sivak, K V; Martov, A G

    2017-12-01

    To investigate experimentally ultrastructural and biochemical signs of acute injury to the renal parenchyma after warm renal ischemia of various duration and subsequent reperfusion. The experiments were performed on 44 healthy conventional female rabbits of the "Chinchilla" breed weighted 2.6-2.7 kg, which were divided into four groups. In the first, control, group included pseudo-operated animals. In the remaining three groups, an experimental model of warm ischemia of renal tissue was created, followed by a 60-minute reperfusion. The renal warm ischemia time was 30, 60 and 90 minutes in the 2nd, 3rd and 4th groups, respectively. Electron microscopy was used to study ultrastructural disturbances of the renal parenchyma. Biochemical signs of acute kidney damage were detected by measuring the following blood serum and/or urine analytes: NGAL, cystatin C, KIM-1, L-FABP, interleukin-18. The glomerular filtration was evaluated by creatinine clearance, which was determined on days 1, 5, 7, 14, 21 and 35 of follow-up. A 30-minute renal warm ischemia followed by a 60-minute reperfusion induced swelling and edema of the brush membrane, vacuolation of the cytoplasm of the endothelial cells of the proximal tubules, and microvilli restructuring. The observed disorders were reversible, and the epithelial cells retained their viability. After 60 minutes of ischemia and 60 minutes of reperfusion, the observed changes in the ultrastructure of the epithelial cells were much more pronounced, some of the epithelial cells were in a state of apoptosis. 90 min of ischemia and 60 min of reperfusion resulted in electron-microscopic signs of the mass cellular death of the tubular epithelium. Concentration in serum and/or biochemical urine markers of acute renal damage increased sharply after ischemic-reperfusion injury. Restoration of indicators was observed only in cases when the renal warm ischemia time did not exceed 60 minutes. The decrease in creatinine clearance occurred in the

  13. Myocardial ischemia and angina pectoris

    International Nuclear Information System (INIS)

    Selwyn, A.P.; Fox, K.M.; Jonathan, A.; Lavender, P.; Watson, I.

    1981-01-01

    Ambulatory monitoring of ST segment changes was performed in 60 patients presenting with angina, positive ECG stress tests and coronary artery disease, 85% of ischemic ECG events were asymptomatic, 37% occurred with no increase in heart rate and 15% of episodes either lasted 20 minutes or more or fluctuated in severity. A controlled pilot study in ten patients showed depression. Radionuclide studies in 50 patients with angina and coronary artery disease have shown that stress (i.e., atrial pacing) produced different patterns of disturbed regional myocardial perfusion related to the patient's exercise capacity and eventually leading to a decrease in regional myocardial perfusion during the ischemic episode. ST segment depression appeared only after the decrease in regional myocardial perfusion. These findings combined with past research suggest that patients with angina and coronary artery disease can suffer frequent asymptomatic disturbances of the regional myocardial perfusion. The frequency of these episodes and the time course for the recovery of the metabolic consequences mean that segments of ventricular myocardium may be constantly abnormal. The relative importance of changes in coronary tone and malfunction of platelets in the diseased coronary tree needs to be examined in clinical research. Pilot studies of antiplatelet agents have shown a significant beneficial effect on episodes of ischemia occurring at night and those occurring without any increase in heart rate. The techniques and observations in these patients with coronary artery disease all suggest that acute transient regional myocardial ischemia is caused by a variety of mechnisms. Further research using objective methods is required to discover the causes of ischemia and to rationalize treatment. (orig./MG) [de

  14. Dynamic Contrast-Enhanced MR Imaging of Renal Ischemia-Reperfusion Injury

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Jun Hyun; Ahn, Myeong Im; Park, Young Ha; Chung, Soo Kyo [Catholic University, Seoul (Korea, Republic of)

    2010-02-15

    To evaluate the usefulness of magnetic resonance imaging (MRI) in a renal ischemia-reperfusion injury. Twenty-four rabbits were randomly divided into four groups, including a sham operated group (n=3). Renal ischemia was induced for 30 minutes (group 1), 60 minutes (group 2) and 120 minutes (group 3). MR imaging was performed before ischemia as well as one hour, 24 hours, and 72 hours after reperfusion. A 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy was performed before ischemia, as well as 24 hours and 72 hours after reperfusion. The signal-to-noise ratio (SNR) on the T2WI, time-relative signal intensity (%RSI) curve on dynamic enhanced images, and relative left renal uptake (%) on DMSA scan were obtained and compared to the histologic findings. The SNR of the cortex on the T2WI changed significantly over the course of the reperfusion time (p<0.001), but was not significantly different among the ischemia groups. The area under the time-%RSI curve gradually decreased from cortex to inner medulla before ischemia, which was reversed and gradually increased after reperfusion. The areas under the time-%RSI curve of outer and inner medulla were significantly different among the ischemia groups (p=0.04, p=0.008). The relative renal uptake (%) of left kidney decreased significantly over the reperfusion time (p=0.03), and was also significantly different among the ischemia groups (p=0.005). Tubular cell necrosis was observed in 16 rabbits (76.2%). The histologic grades of group 3 were higher than those of group 1 and group 2 (p=0.002). Even in rabbits without tubular cell necrosis, the areas under the time-%RSI curves of the cortex, outer, and inner medulla after a 72 hour reperfusion time were significantly lower than those before ischemia (p=0.007, p=0.005, p=0.004). The results of this study suggest that dynamic enhanced MR imaging could be a useful tool for the evaluation of renal ischemia and reperfusion injury.

  15. Revascularization for acute mesenteric ischemia.

    Science.gov (United States)

    Ryer, Evan J; Kalra, Manju; Oderich, Gustavo S; Duncan, Audra A; Gloviczki, Peter; Cha, Stephen; Bower, Thomas C

    2012-06-01

    Acute mesenteric ischemia (AMI) remains difficult to diagnose, carries a high rate of complications, and is associated with significant mortality. We evaluated our experience with AMI over the last 2 decades to evaluate changes in management and assess current outcomes. Data from consecutive patients who underwent arterial revascularization for AMI over a 20-year period (January 1990-January 2010) were retrospectively reviewed. Patient demographics, treatment modalities, and outcomes over the last decade (2000-2010) were compared with those of the preceding decade (1990-1999) previously reported. Over the last 2 decades, 93 patients with AMI underwent emergency arterial revascularization. Forty-five patients were treated during the 1990s and 48 during the 2000s. The majority of these patients were transferred from outside facilities. Patient demographics and risk factors were similar between the 2 decades with the exception that the more contemporary patients were significantly older (65.1 ± 14 vs 71.3 ± 14; P = .04). Etiology remained constant between the groups with in situ thrombosis being the most common followed by arterial embolus. The majority of patients were treated with open revascularization. Endovascular therapy alone or as a hybrid procedure was used in 11 total patients, eight of which were treated in the last 10 years. The use of second-look laparotomy was much more liberal in the last decade (80% vs 48%; P = .003) Thirty-day mortality was 27% in the 1990s and 17% during the 2000s (P = 0.28). Major adverse events occurred in 47% of patients with no difference between decades. There was no significant difference in outcomes between open and endovascular revascularization. On univariate analysis, elevated SVS comorbidity score, congestive heart failure, and chronic kidney disease predicted early death, while a history of chronic mesenteric ischemia appeared protective. On multivariate analysis, no factor independently predicted perioperative

  16. Study on pretreatment of FPS-1 in rats with hepatic ischemia-reperfusion injury.

    Science.gov (United States)

    Lin, Shiqing; Liu, Kexuan; Wu, Weikang; Chen, Chao; Wang, Zhi; Zhang, Xuanhong

    2009-01-01

    This study was designed to determine whether FPS-1, the water-soluble polysaccharide isolated from fuzi, protected against hepatic damage in hepatic ischemia-reperfusion injury in rats, and its mechanism. SD rats were subjected to 60 min of hepatic ischemia, followed by 120 min reperfusion. FPS-1 (160 mg/kg/day) was administered orally for 5 days before ischemia-reperfusion injury in treatment group. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and albumin (ALB) were assayed to evaluate liver functions. Liver samples were taken for histological examination and determination of malondialdehyde (MDA), superoxide dismutase (SOD), that catalase (CAT) in liver. Na(+)-K(+)-ATPase and Ca(2+)-ATPase in mitochondria were measured with colorimetry method. Morphological changes were also investigated by using both light microscopy and electron microscopy (EM). In addition, apoptosis and oncosis were detected by Annexin V-FITC/PI immunofluorescent flow cytometry analysis. Serum AST and ALT levels were elevated in groups exposed to ischemia-reperfusion (p FPS-1 reversed all these biochemical parameters as well as histological alterations, evidently by increased SOD, CAT, reduced MDA and histological scores compared to the model group (p FPS-1 could attenuate the necrotic states by the detection of immunofluorescent flow cytometry analysis. Pretreatment with FPS-1 reduced hepatic ischemia-reperfusion injury through its potent antioxidative effects and attenuation of necrotic states.

  17. Dynamics of epileptic activity in a peculiar case of childhood absence epilepsy and correlation with thalamic levels of GABA

    Directory of Open Access Journals (Sweden)

    Alberto Leal

    2016-01-01

    Significance: In a clinical case of CAE with EEG and fMRI-BOLD manifestations restricted to one hemisphere, we found an associated increase in thalamic GABA concentration consistent with a role for this abnormality in human CAE.

  18. Chick embryo partial ischemia model: a new approach to study ischemia ex vivo.

    Directory of Open Access Journals (Sweden)

    Syamantak Majumder

    Full Text Available BACKGROUND: Ischemia is a pathophysiological condition due to blockade in blood supply to a specific tissue thus damaging the physiological activity of the tissue. Different in vivo models are presently available to study ischemia in heart and other tissues. However, no ex vivo ischemia model has been available to date for routine ischemia research and for faster screening of anti-ischemia drugs. In the present study, we took the opportunity to develop an ex vivo model of partial ischemia using the vascular bed of 4(th day incubated chick embryo. METHODOLOGY/PRINCIPAL FINDINGS: Ischemia was created in chick embryo by ligating the right vitelline artery using sterile surgical suture. Hypoxia inducible factor- 1 alpha (HIF-1alpha, creatine phospho kinase-MB and reactive oxygen species in animal tissues and cells were measured to confirm ischemia in chick embryo. Additionally, ranolazine, N-acetyl cysteine and trimetazidine were administered as an anti-ischemic drug to validate the present model. Results from the present study depicted that blocking blood flow elevates HIF-1alpha, lipid peroxidation, peroxynitrite level in ischemic vessels while ranolazine administration partially attenuates ischemia driven HIF-1alpha expression. Endothelial cell incubated on ischemic blood vessels elucidated a higher level of HIF-1alpha expression with time while ranolazine treatment reduced HIF-1alpha in ischemic cells. Incubation of caprine heart strip on chick embryo ischemia model depicted an elevated creatine phospho kinase-MB activity under ischemic condition while histology of the treated heart sections evoked edema and disruption of myofibril structures. CONCLUSIONS/SIGNIFICANCE: The present study concluded that chick embryo partial ischemia model can be used as a novel ex vivo model of ischemia. Therefore, the present model can be used parallel with the known in vivo ischemia models in understanding the mechanistic insight of ischemia development and in

  19. The effect of mitochondrial calcium uniporter on mitochondrial fission in hippocampus cells ischemia/reperfusion injury

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lantao; Li, Shuhong; Wang, Shilei, E-mail: wshlei@aliyun.com; Yu, Ning; Liu, Jia

    2015-06-05

    The mitochondrial calcium uniporter (MCU) transports free Ca{sup 2+} into the mitochondrial matrix, maintaining Ca{sup 2+} homeostasis, thus regulates the mitochondrial morphology. Previous studies have indicated that there was closely crosstalk between MCU and mitochondrial fission during the process of ischemia/reperfusion injury. This study constructed a hypoxia reoxygenation model using primary hippocampus neurons to mimic the cerebral ischemia/reperfusion injury and aims to explore the exactly effect of MCU on the mitochondrial fission during the process of ischemia/reperfusion injury and so as the mechanisms. Our results found that the inhibitor of the MCU, Ru360, decreased mitochondrial Ca{sup 2+} concentration, suppressed the expression of mitochondrial fission protein Drp1, MIEF1 and Fis1, and thus improved mitochondrial morphology significantly. Whereas spermine, the agonist of the MCU, had no significant impact compared to the I/R group. This study demonstrated that the MCU regulates the process of mitochondrial fission by controlling the Ca{sup 2+} transport, directly upregulating mitochondrial fission proteins Drp1, Fis1 and indirectly reversing the MIEF1-induced mitochondrial fusion. It also provides new targets for brain protection during ischemia/reperfusion injury. - Highlights: • We study MCU with primary neuron culture. • MCU induces mitochondrial fission. • MCU reverses MIEF1 effect.

  20. An Automatic Occlusion Device for Remote Control of Tumor Tissue Ischemia

    Science.gov (United States)

    El-Dahdah, Hamid; Wang, Bei; He, Guanglong; Xu, Ronald X.

    2015-01-01

    We developed an automatic occlusion device for remote control of tumor tissue ischemia. The device consists of a flexible cannula encasing a shape memory alloy wire with its distal end connected to surgical suture. Regional tissue occlusion was tested on both the benchtop and the animal models. In the benchtop test, the occlusion device introduced quantitative and reproducible changes of blood flow in a tissue simulating phantom embedding a vessel simulator. In the animal test, the device generated a cyclic pattern of reversible ischemia in the right hinder leg tissue of a black male C57BL/6 mouse. We also developed a multimodal detector that integrates near infrared spectroscopy and electron paramagnetic resonance spectroscopy for continuous monitoring of tumor tissue oxygenation, blood content, and oxygen tension changes. The multimodal detector was tested on a cancer xenograft nude mouse undergoing reversible tumor ischemia. The automatic occlusion device and the multi-modal detector can be potentially integrated for closed-loop feedback control of tumor tissue ischemia. Such an integrated occlusion device may be used in multiple clinical applications such as regional hypoperfusion control in tumor resection surgeries and thermal ablation processes. In addition, the proposed occlusion device can also be used as a research tool to understand tumor oxygen transport and hemodynamic characteristics. PMID:20082532

  1. Metabolic Adaptation to Muscle Ischemia

    Science.gov (United States)

    Cabrera, Marco E.; Coon, Jennifer E.; Kalhan, Satish C.; Radhakrishnan, Krishnan; Saidel, Gerald M.; Stanley, William C.

    2000-01-01

    Although all tissues in the body can adapt to varying physiological/pathological conditions, muscle is the most adaptable. To understand the significance of cellular events and their role in controlling metabolic adaptations in complex physiological systems, it is necessary to link cellular and system levels by means of mechanistic computational models. The main objective of this work is to improve understanding of the regulation of energy metabolism during skeletal/cardiac muscle ischemia by combining in vivo experiments and quantitative models of metabolism. Our main focus is to investigate factors affecting lactate metabolism (e.g., NADH/NAD) and the inter-regulation between carbohydrate and fatty acid metabolism during a reduction in regional blood flow. A mechanistic mathematical model of energy metabolism has been developed to link cellular metabolic processes and their control mechanisms to tissue (skeletal muscle) and organ (heart) physiological responses. We applied this model to simulate the relationship between tissue oxygenation, redox state, and lactate metabolism in skeletal muscle. The model was validated using human data from published occlusion studies. Currently, we are investigating the difference in the responses to sudden vs. gradual onset ischemia in swine by combining in vivo experimental studies with computational models of myocardial energy metabolism during normal and ischemic conditions.

  2. [Brain protection against cerebral ischemia].

    Science.gov (United States)

    Kitagawa, Kazuo

    2013-01-01

    Previous clinical trials failed to show the benefit of several potentially protective drugs in acute ischemic stroke. However, there would be three main approaches for brain protection against stroke. The first is to develop a novel thrombolytic agent which is more efficient and safer than alteplase. Tenecteplase and desmoteplase are in progress as a new thrombolytic drug. The second strategy is to augment collateral circulation through leptomeningeal anastomosis. Administration of G-CSF could enhance arteriogenesis, but it takes several days to develop functional collateral. For this purpose, partial aortic balloon clumping or stimulation of pterygopalatine ganglion may be promising. The third one is to protect neurovascular unit against reperfusion injury. Brain hypothermia is the most effective strategy in experimental ischemia, and the clinical trial for hypothermia combined with thrombolysis therapy is in progress. Activation of endogenous protective response, as presented by ischemic tolerance, has focused on remote ischemic conditioning. Although the precise mechanisms of remote preconditioning remain unclear, intermittent limb ischemia is a safe approach. Remote ischemic conditioning is now investigated in acute patients with thrombolysis therapy.

  3. Hypofractionated Stereotactic Radiosurgery in a Large Bilateral Thalamic and Basal Ganglia Arteriovenous Malformation

    Directory of Open Access Journals (Sweden)

    Janet Lee

    2013-01-01

    Full Text Available Purpose. Arteriovenous malformations (AVMs in the basal ganglia and thalamus have a more aggressive natural history with a higher morbidity and mortality than AVMs in other locations. Optimal treatment—complete obliteration without new neurological deficits—is often challenging. We present a patient with a large bilateral basal ganglia and thalamic AVM successfully treated with hypofractionated stereotactic radiosurgery (HFSRS with intensity modulated radiotherapy (IMRT. Methods. The patient was treated with hypofractionated stereotactic radiosurgery to 30 Gy at margin in 5 fractions of 9 static fields with a minimultileaf collimator and intensity modulated radiotherapy. Results. At 10 months following treatment, digital subtraction angiography showed complete obliteration of the AVM. Conclusions. Large bilateral thalamic and basal ganglia AVMs can be successfully treated with complete obliteration by HFSRS with IMRT with relatively limited toxicity. Appropriate caution is recommended.

  4. Interactions between thalamic and cortical rhythms during semantic memory recall in human

    Science.gov (United States)

    Slotnick, Scott D.; Moo, Lauren R.; Kraut, Michael A.; Lesser, Ronald P.; Hart, John, Jr.

    2002-04-01

    Human scalp electroencephalographic rhythms, indicative of cortical population synchrony, have long been posited to reflect cognitive processing. Although numerous studies employing simultaneous thalamic and cortical electrode recording in nonhuman animals have explored the role of the thalamus in the modulation of cortical rhythms, direct evidence for thalamocortical modulation in human has not, to our knowledge, been obtained. We simultaneously recorded from thalamic and scalp electrodes in one human during performance of a cognitive task and found a spatially widespread, phase-locked, low-frequency rhythm (7-8 Hz) power decrease at thalamus and scalp during semantic memory recall. This low-frequency rhythm power decrease was followed by a spatially specific, phase-locked, fast-rhythm (21-34 Hz) power increase at thalamus and occipital scalp. Such a pattern of thalamocortical activity reflects a plausible neural mechanism underlying semantic memory recall that may underlie other cognitive processes as well.

  5. A Case of Midbrain and Thalamic Infarction Involving Artery of Percheron

    Directory of Open Access Journals (Sweden)

    Muhammad Almamun

    2015-03-01

    Full Text Available Blood supply to the thalamus and brainstem have frequent anatomic variations. One of these is where all the perforators to the above areas arise from a single branch of the posterior cerebral artery commonly known as the artery of Percheron. Infarction involving this artery leading to bilateral thalamic and midbrain lesions is not uncommon, but can cause diagnostic difficulties due to the varying clinical presentations possible and the wide differentials. Early brain imaging and diagnosis is important for initiating appropriate treatment. In this case report, we discuss a patient who presented with an artery of Percheron related stroke affecting the mid brain and paramedian thalamic areas. We also discuss the differentials of presentations with similar symptoms.

  6. Thalamic structures and associated cognitive functions: Relations with age and aging

    Science.gov (United States)

    Fama, Rosemary; Sullivan, Edith V.

    2015-01-01

    The thalamus, with its cortical, subcortical, and cerebellar connections, is a critical node in networks supporting cognitive functions known to decline in normal aging, including component processes of memory and executive functions of attention and information processing. The macrostructure, microstructure, and neural connectivity of the thalamus changes across the adult lifespan. Structural and functional magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) have demonstrated, regional thalamic volume shrinkage and microstructural degradation, with anterior regions generally more compromised than posterior regions. The integrity of selective thalamic nuclei and projections decline with advancing age, particularly those in thalamofrontal, thalamoparietal, and thalamolimbic networks. This review presents studies that assess the relations between age and aging and the structure, function, and connectivity of the thalamus and associated neural networks and focuses on their relations with processes of attention, speed of information processing, and working and episodic memory. PMID:25862940

  7. COMMUNICATION Designing a somatosensory neural prosthesis: percepts evoked by different patterns of thalamic stimulation

    Science.gov (United States)

    Heming, Ethan; Sanden, Andrew; Kiss, Zelma H. T.

    2010-12-01

    Although major advances have been made in the development of motor prostheses, fine motor control requires intuitive somatosensory feedback. Here we explored whether a thalamic site for a somatosensory neural prosthetic could provide natural somatic sensation to humans. Different patterns of electrical stimulation (obtained from thalamic spike trains) were applied in patients undergoing deep brain stimulation surgery. Changes in pattern produced different sensations, while preserving somatotopic representation. While most percepts were reported as 'unnatural', some stimulations produced more 'natural' sensations than others. However, the additional patterns did not elicit more 'natural' percepts than high-frequency (333 Hz) electrical stimulation. These features suggest that despite some limitations, the thalamus may be a feasible site for a somatosensory neural prosthesis and different stimulation patterns may be useful in its development.

  8. Thalamic deactivation at sleep onset precedes that of the cerebral cortex in humans

    Science.gov (United States)

    Magnin, Michel; Rey, Marc; Bastuji, Hélène; Guillemant, Philippe; Mauguière, François; Garcia-Larrea, Luis

    2010-01-01

    Thalamic and cortical activities are assumed to be time-locked throughout all vigilance states. Using simultaneous intracortical and intrathalamic recordings, we demonstrate here that the thalamic deactivation occurring at sleep onset most often precedes that of the cortex by several minutes, whereas reactivation of both structures during awakening is synchronized. Delays between thalamus and cortex deactivations can vary from one subject to another when a similar cortical region is considered. In addition, heterogeneity in activity levels throughout the cortical mantle is larger than previously thought during the descent into sleep. Thus, asynchronous thalamo-cortical deactivation while falling asleep probably explains the production of hypnagogic hallucinations by a still-activated cortex and the common self-overestimation of the time needed to fall asleep. PMID:20142493

  9. Crossed cerebellar and uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease

    International Nuclear Information System (INIS)

    Akiyama, H.; Harrop, R.; McGeer, P.L.; Peppard, R.; McGeer, E.G.

    1989-01-01

    We detected crossed cerebellar as well as uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease by positron emission tomography (PET) using 18 F-fluorodeoxyglucose. We studied a series of 26 consecutive, clinically diagnosed Alzheimer cases, including 6 proven by later autopsy, and compared them with 9 age-matched controls. We calculated asymmetry indices (AIs) of cerebral metabolic rate for matched left-right regions of interest (ROIs) and determined the extent of diaschisis by correlative analyses. For the Alzheimer group, we found cerebellar AIs correlated negatively, and thalamic AIs positively, with those of the cerebral hemisphere and frontal, temporal, parietal, and angular cortices, while basal ganglia AIs correlated positively with frontal cortical AIs. The only significant correlation of AIs for normal subjects was between the thalamus and cerebral hemisphere. These data indicate that PET is a sensitive technique for detecting diaschisis

  10. [Motor neglect of thalamic origin: report on two cases (author's transl)].

    Science.gov (United States)

    Laplane, D; Escourolle, R; Degos, J D; Sauron, B; Massiou, H

    1982-01-01

    Two cases of thalamic lesions with motor neglect are presented. The syndrome of motor neglect was complete in those cases with a) underutilization of left limbs, but good utilization upon verbal orders, b) loss of placement reaction, c) weakness of movement when hand was approaching the target, d) weakness of motor reaction to nociceptive stimuli. Those cases confirm that motor neglect exists after thalamic lesions and bring pathologic clues for topographic discussion. Motor neglect seems to be a particular case of partial unilateral neglect throwing some doubt on the hypothesis of a global trouble of hemispheric activation. Prevalence of left motor neglects suggests some linkage between propositional motility and language. One may suppose that in the right hemisphere language is able to have a vicarious action when spontaneous activation is lost; at the opposite, in the left hemisphere language and motility would be too linked to let this dissociation be generally possible.

  11. Surgical management of thalamic gliomas: case selection, technical considerations, and review of literature.

    Science.gov (United States)

    Sai Kiran, Narayanam Anantha; Thakar, Sumit; Dadlani, Ravi; Mohan, Dilip; Furtado, Sunil Valentine; Ghosal, Nandita; Aryan, Saritha; Hegde, Alangar S

    2013-07-01

    This study aimed to identify (1) the thalamic gliomas suitable for surgical resection and (2) the appropriate surgical approach based on their location and the displacement of the posterior limb of the internal capsule (PLIC). A retrospective study over a 5-year period (from 2006 to 2010) was performed in 41 patients with thalamic gliomas. The mean age of these patients was 20.4 years (range, 2-65 years). Twenty (49 %) tumors were thalamic, 19 (46 %) were thalamopeduncular, and 2 (5 %) were bilateral. The PLIC, based on T2-weighted magnetic resonance axial sections, was displaced anterolaterally in 23 (56 %) cases and laterally in 6 (14 %) cases. It was involved by lesion in eight (20 %) cases and could not be identified in four (10 %) cases. Resection, favored in patients with well-defined, contrast-enhancing lesions, was performed in 34 (83 %) cases, while a biopsy was resorted to in 7 (17 %) cases. A gross total resection or near total resection (>90 %) could be achieved in 26 (63 %) cases. The middle temporal gyrus approach, used when the PLIC was displaced anterolaterally, was the commonly used approach (63.5 %). Common pathologies were pilocytic astrocytoma (58 %) in children and grade III/IV astrocytomas (86 %) in adults. Preoperative motor deficits improved in 64 % of the patients with pilocytic lesions as compared to 0 % in patients with grade III/IV lesions (P value, 0.001). Postoperatively, two patients (5 %) had marginal worsening of motor power, two patients developed visual field defects, and one patient developed a third nerve paresis. Radical resection of thalamic gliomas is a useful treatment modality in a select subset of patients and is the treatment of choice for pilocytic astrocytomas. Tailoring the surgical approach, depending on the relative position of the PLIC, has an important bearing on outcome.

  12. Passive accessory joint mobilization in the multimodal management of chronic dysesthesia following thalamic stroke.

    Science.gov (United States)

    Griffin, Kristina; O'Hearn, Michael; Franck, Carla C; Courtney, Carol A

    2018-03-20

    Case Report. Stroke is the most common cause of long-term disability. Dysesthesia, an unpleasant sensory disturbance, is common following thalamic stroke and evidence-based interventions for this impairment are limited. The purpose of this case report was to describe a decrease in dysesthesia following manual therapy intervention in a patient with history of right lacunar thalamic stroke. A 66-year-old female presented with tingling and dysesthesia in left hemisensory distribution including left trunk and upper/lower extremities, limiting function. Decreased left shoulder active range of motion, positive sensory symptoms but no sensory loss in light touch was found. She denied pain and moderate shoulder muscular weakness was demonstrated. Laterality testing revealed right/left limb discrimination deficits and neglect-like symptoms were reported. Passive accessory joint motion assessment of glenohumeral and thoracic spine revealed hypomobility and provoked dysesthesia. Interventions included passive oscillatory joint mobilization of glenohumeral joint, thoracic spine, ribs and shoulder strengthening. After six sessions, shoulder function, active range of motion, strength improved and dysesthesia decreased. Global Rating of Change Scale was +5 and QuickDASH score decreased from 45% to 22% disability. Laterality testing was unchanged. Manual therapy may be a beneficial intervention in management of thalamic stroke-related dysesthesia. Implications for Rehabilitation While pain is common following thalamic stroke, patients may present with chronic paresthesia or dysesthesia, often in a hemisensory distribution. Passive movement may promote inhibition of hyperexcitable cortical pathways, which may diminish aberrant sensations. Passive oscillatory manual therapy may be an effective way to treat sensory disturbances such as paresthesias or dysesthesia.

  13. Sensory processing of deep tissue nociception in the rat spinal cord and thalamic ventrobasal complex.

    Science.gov (United States)

    Sikandar, Shafaq; West, Steven J; McMahon, Stephen B; Bennett, David L; Dickenson, Anthony H

    2017-07-01

    Sensory processing of deep somatic tissue constitutes an important component of the nociceptive system, yet associated central processing pathways remain poorly understood. Here, we provide a novel electrophysiological characterization and immunohistochemical analysis of neural activation in the lateral spinal nucleus (LSN). These neurons show evoked activity to deep, but not cutaneous, stimulation. The evoked responses of neurons in the LSN can be sensitized to somatosensory stimulation following intramuscular hypertonic saline, an acute model of muscle pain, suggesting this is an important spinal relay site for the processing of deep tissue nociceptive inputs. Neurons of the thalamic ventrobasal complex (VBC) mediate both cutaneous and deep tissue sensory processing, but in contrast to the lateral spinal nucleus our electrophysiological studies do not suggest the existence of a subgroup of cells that selectively process deep tissue inputs. The sensitization of polymodal and thermospecific VBC neurons to mechanical somatosensory stimulation following acute muscle stimulation with hypertonic saline suggests differential roles of thalamic subpopulations in mediating cutaneous and deep tissue nociception in pathological states. Overall, our studies at both the spinal (lateral spinal nucleus) and supraspinal (thalamic ventrobasal complex) levels suggest a convergence of cutaneous and deep somatosensory inputs onto spinothalamic pathways, which are unmasked by activation of muscle nociceptive afferents to produce consequent phenotypic alterations in spinal and thalamic neural coding of somatosensory stimulation. A better understanding of the sensory pathways involved in deep tissue nociception, as well as the degree of labeled line and convergent pathways for cutaneous and deep somatosensory inputs, is fundamental to developing targeted analgesic therapies for deep pain syndromes. © 2017 University College London. Physiological Reports published by Wiley Periodicals

  14. Increased thalamic resting-state connectivity as a core driver of LSD-induced hallucinations.

    Science.gov (United States)

    Müller, F; Lenz, C; Dolder, P; Lang, U; Schmidt, A; Liechti, M; Borgwardt, S

    2017-12-01

    It has been proposed that the thalamocortical system is an important site of action of hallucinogenic drugs and an essential component of the neural correlates of consciousness. Hallucinogenic drugs such as LSD can be used to induce profoundly altered states of consciousness, and it is thus of interest to test the effects of these drugs on this system. 100 μg LSD was administrated orally to 20 healthy participants prior to fMRI assessment. Whole brain thalamic functional connectivity was measured using ROI-to-ROI and ROI-to-voxel approaches. Correlation analyses were used to explore relationships between thalamic connectivity to regions involved in auditory and visual hallucinations and subjective ratings on auditory and visual drug effects. LSD caused significant alterations in all dimensions of the 5D-ASC scale and significantly increased thalamic functional connectivity to various cortical regions. Furthermore, LSD-induced functional connectivity measures between the thalamus and the right fusiform gyrus and insula correlated significantly with subjective auditory and visual drug effects. Hallucinogenic drug effects might be provoked by facilitations of cortical excitability via thalamocortical interactions. Our findings have implications for the understanding of the mechanism of action of hallucinogenic drugs and provide further insight into the role of the 5-HT 2A -receptor in altered states of consciousness. © 2017 The Authors Acta Psychiatrica Scandinavica Published by John Wiley & Sons Ltd.

  15. Assessment of paramedian thalamic infarcts: MR imaging, clinical features and prognosis

    International Nuclear Information System (INIS)

    Weidauer, Stefan; Zanella, Friedhelm E.; Lanfermann, Heinrich; Nichtweiss, Michael

    2004-01-01

    Considering the highly variable vascular supply of the thalamic nuclei, MRI and clinical syndromes can be heterogeneous in ischemic diseases. We attempt to determine MRI pattern and to analyse neurological features and prognosis of paramedian infarcts. In a prospective case series within 5 years from 1999 to 2003, MRI, MRA and clinical symptoms of 38 consecutive patients were analysed. The inferomedial (posterior thalamoperforating artery) territory was affected in 89%, and lesions in the anterolateral (tuberothalamic artery) territory occurred in 42%. However, definite attribution to anterolateral or inferomedial territories was not possible in 13%. Neurological manifestations were somnolence (87%), hemisyndromes (79%), cognitive deficits (58%), oculomotor nerve palsies (53%) and vertical gaze palsies (39%). The most common aetiologies were cardiac embolism (42%), intraarterial embolism (16%), small vessel disease (13%) and large artery arteriosclerosis (13%). Pathological MRA findings were encountered in 55%, and in 18%, lesions were only visible on diffusion-weighted imaging. Correlation of MRI pattern and neurological symptoms points out anterolateral thalamic lesions as the cause of amnestic deficits. Intracranial MRA allows a non-invasive prediction of basilar tip occlusion. Our results underline the necessity of additional diffusion-weighted imaging in detecting small thalamic and midbrain lesions. (orig.)

  16. Model-based iterative learning control of Parkinsonian state in thalamic relay neuron

    Science.gov (United States)

    Liu, Chen; Wang, Jiang; Li, Huiyan; Xue, Zhiqin; Deng, Bin; Wei, Xile

    2014-09-01

    Although the beneficial effects of chronic deep brain stimulation on Parkinson's disease motor symptoms are now largely confirmed, the underlying mechanisms behind deep brain stimulation remain unclear and under debate. Hence, the selection of stimulation parameters is full of challenges. Additionally, due to the complexity of neural system, together with omnipresent noises, the accurate model of thalamic relay neuron is unknown. Thus, the iterative learning control of the thalamic relay neuron's Parkinsonian state based on various variables is presented. Combining the iterative learning control with typical proportional-integral control algorithm, a novel and efficient control strategy is proposed, which does not require any particular knowledge on the detailed physiological characteristics of cortico-basal ganglia-thalamocortical loop and can automatically adjust the stimulation parameters. Simulation results demonstrate the feasibility of the proposed control strategy to restore the fidelity of thalamic relay in the Parkinsonian condition. Furthermore, through changing the important parameter—the maximum ionic conductance densities of low-threshold calcium current, the dominant characteristic of the proposed method which is independent of the accurate model can be further verified.

  17. Clinical, neuropsychological, and pre-stimulus dorsomedial thalamic nucleus electrophysiological data in deep brain stimulation patients

    Directory of Open Access Journals (Sweden)

    Catherine M. Sweeney-Reed

    2016-09-01

    Full Text Available The data presented here comprise clinical, neuropsychological, and intrathalamic electrophysiological data from 7 patients with pharmacoresistant focal epilepsy and are related to the article “Pre-stimulus thalamic theta power predicts human memory formation” C.M. Sweeney-Reed, T. Zaehle, J. Voges, F.C. Schmitt, L. Buentjen, K. Kopitzki, et al. (2016 [1]. The patients participated in a memory paradigm after receiving electrodes implanted in the DMTN due to the surgical approach taken in electrode insertion for deep brain stimulation of the anterior thalamic nucleus. Epilepsy duration and pre-operative neuropsychological tests provide an indication of the profile of patients receiving intrathalamic electrode implantation and the memory capabilities in such a patient group. The electrophysiological data were recorded from the right DMTN preceding stimulus presentation during intentional memory encoding. The patients viewed a series of photographic scenes, which they judged as indoors or outdoors. The 900 ms epochs prior to stimulus presentation were labeled as preceding successful or unsuccessful subsequent memory formation according to a subsequent memory test for the items. The difference between theta power preceding successful versus unsuccessful subsequent memory formation is shown against time for each patient individually. Keywords: Memory encoding, Dorsomedial thalamic nucleus, Pre-stimulus theta

  18. The neurobiology of thalamic amnesia: Contributions of medial thalamus and prefrontal cortex to delayed conditional discrimination.

    Science.gov (United States)

    Mair, Robert G; Miller, Rikki L A; Wormwood, Benjamin A; Francoeur, Miranda J; Onos, Kristen D; Gibson, Brett M

    2015-07-01

    Although medial thalamus is well established as a site of pathology associated with global amnesia, there is uncertainty about which structures are critical and how they affect memory function. Evidence from human and animal research suggests that damage to the mammillothalamic tract and the anterior, mediodorsal (MD), midline (M), and intralaminar (IL) nuclei contribute to different signs of thalamic amnesia. Here we focus on MD and the adjacent M and IL nuclei, structures identified in animal studies as critical nodes in prefrontal cortex (PFC)-related pathways that are necessary for delayed conditional discrimination. Recordings of PFC neurons in rats performing a dynamic delayed non-matching-to position (DNMTP) task revealed discrete populations encoding information related to planning, execution, and outcome of DNMTP-related actions and delay-related activity signaling previous reinforcement. Parallel studies recording the activity of MD and IL neurons and examining the effects of unilateral thalamic inactivation on the responses of PFC neurons demonstrated a close coupling of central thalamic and PFC neurons responding to diverse aspects of DNMTP and provide evidence that thalamus interacts with PFC neurons to give rise to complex goal-directed behavior exemplified by the DNMTP task. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Contralateral Supracerebellar-Infratentorial Approach for Resection of Thalamic Cavernous Malformations.

    Science.gov (United States)

    Mascitelli, Justin; Burkhardt, Jan-Karl; Gandhi, Sirin; Lawton, Michael T

    2018-02-26

    Surgical resection of cavernous malformations (CM) in the posterior thalamus, pineal region, and midbrain tectum is technically challenging owing to the presence of adjacent eloquent cortex and critical neurovascular structures. Various supracerebellar infratentorial (SCIT) approaches have been used in the surgical armamentarium targeting lesions in this region, including the median, paramedian, and extreme lateral variants. Surgical view of a posterior thalamic CM from the traditional ipsilateral vantage point may be obscured by occipital lobe and tentorium. To describe a novel surgical approach via a contralateral SCIT (cSCIT) trajectory for resecting posterior thalamic CMs. From 1997 to 2017, 75 patients underwent the SCIT approach for cerebrovascular/oncologic pathology by the senior author. Of these, 30 patients underwent the SCIT approach for CM resection, and 3 patients underwent the cSCIT approach. Historical patient data, radiographic features, surgical technique, and postoperative neurological outcomes were evaluated in each patient. All 3 patients presented with symptomatic CMs within the right posterior thalamus with radiographic evidence of hemorrhage. All surgeries were performed in the sitting position. There were no intraoperative complications. Neuroimaging demonstrated complete CM resection in all cases. There were no new or worsening neurological deficits or evidence of rebleeding/recurrence noted postoperatively. This study establishes the surgical feasibility of a contralateral SCIT approach in resection of symptomatic thalamic CMs It demonstrates the application for this procedure in extending the surgical trajectory superiorly and laterally and maximizing safe resectability of these deep CMs with gravity-assisted brain retraction.

  20. Long-term outcome of thalamic deep brain stimulation in two patients with Tourette syndrome.

    Science.gov (United States)

    Ackermans, Linda; Duits, Annelien; Temel, Yasin; Winogrodzka, Ania; Peeters, Frenk; Beuls, Emile A M; Visser-Vandewalle, Veerle

    2010-10-01

    Thalamic deep brain stimulation for intractable Tourette Syndrome was introduced in 1999 by Vandewalle et al. In this follow-up study, the authors report on the long-term (6 and 10 years) outcome in terms of tic reduction, cognition, mood and side effects of medial thalamic deep brain stimulation in two previously described Tourette patients. The authors compared the outcome of two patients at 6 and 10 years after surgery with their preoperative status and after 8 months and 5 years of treatment, respectively. Standardised video recordings were scored by three independent investigators. Both patients underwent (neuro)psychological assessment at all time points of follow-up. Tic improvement observed at 5 years in patient 1 (90.1%) was maintained at 10 years (92.6%). In patient 2, the tic improvement at 8 months (82%) was slightly decreased at 6 years (78%). During follow-up, case 1 revealed no changes in cognition, but case 2 showed a decrease in verbal fluency and learning which was in line with his subjective reports. Case 2 showed a slight decrease in depression, but overall psychopathology was still high at 6 years after surgery with an increase in anger and aggression together with difficulties in social adaptation. Besides temporary hardware-related complications, no distressing adverse effects were observed. Bilateral thalamic stimulation may provide sustained tic benefit after at least 6 years, but to maximise overall outcome, attention is needed for postoperative psychosocial adaptation, already prior to surgery.

  1. Subset of Cortical Layer 6b Neurons Selectively Innervates Higher Order Thalamic Nuclei in Mice.

    Science.gov (United States)

    Hoerder-Suabedissen, Anna; Hayashi, Shuichi; Upton, Louise; Nolan, Zachary; Casas-Torremocha, Diana; Grant, Eleanor; Viswanathan, Sarada; Kanold, Patrick O; Clasca, Francisco; Kim, Yongsoo; Molnár, Zoltán

    2018-05-01

    The thalamus receives input from 3 distinct cortical layers, but input from only 2 of these has been well characterized. We therefore investigated whether the third input, derived from layer 6b, is more similar to the projections from layer 6a or layer 5. We studied the projections of a restricted population of deep layer 6 cells ("layer 6b cells") taking advantage of the transgenic mouse Tg(Drd1a-cre)FK164Gsat/Mmucd (Drd1a-Cre), that selectively expresses Cre-recombinase in a subpopulation of layer 6b neurons across the entire cortical mantle. At P8, 18% of layer 6b neurons are labeled with Drd1a-Cre::tdTomato in somatosensory cortex (SS), and some co-express known layer 6b markers. Using Cre-dependent viral tracing, we identified topographical projections to higher order thalamic nuclei. VGluT1+ synapses formed by labeled layer 6b projections were found in posterior thalamic nucleus (Po) but not in the (pre)thalamic reticular nucleus (TRN). The lack of TRN collaterals was confirmed with single-cell tracing from SS. Transmission electron microscopy comparison of terminal varicosities from layer 5 and layer 6b axons in Po showed that L6b varicosities are markedly smaller and simpler than the majority from L5. Our results suggest that L6b projections to the thalamus are distinct from both L5 and L6a projections.

  2. Disrupted Auto-Activation, Dysexecutive and Confabulating Syndrome Following Bilateral Thalamic and Right Putaminal Stroke

    Directory of Open Access Journals (Sweden)

    Lieve De Witte

    2008-01-01

    Full Text Available Objective: Clinical, neuropsychological, structural and functional neuroimaging results are reported in a patient who developed a unique combination of symptoms after a bi-thalamic and right putaminal stroke. The symptoms consisted of dysexecutive disturbances associated with confabulating behavior and auto-activation deficits. Background: Basal ganglia and thalamic lesions may result in a variety of motor, sensory, neuropsychological and behavioral syndromes. However, the combination of a dysexecutive syndrome complicated at the behavioral level with an auto-activation and confabulatory syndrome has never been reported. Methods: Besides clinical and neuroradiological investigations, an extensive set of standardized neuropsychological tests was carried out. Results: In the post-acute phase of the stroke, a dysexecutive syndrome was found in association with confabulating behavior and auto-activation deficits. MRI showed focal destruction of both thalami and the right putamen. Quantified ECD SPECT revealed bilateral hypoperfusions in the basal ganglia and thalamus but no perfusion deficits were found at the cortical level. Conclusion: The combination of disrupted auto-activation, dysexecutive and confabulating syndrome in a single patient following isolated subcortical damage renders this case exceptional. Although these findings do not reveal a functional disruption of the striato-ventral pallidal-thalamic-frontomesial limbic circuitry, they add to the understanding of the functional role of the basal ganglia in cognitive and behavioral syndromes.

  3. Myocardial perfusion in silent myocardial ischemia

    International Nuclear Information System (INIS)

    Narita, Michihiro; Kurihara, Tadashi; Murano, Kenichi; Usami, Masahisa

    1989-01-01

    To investigate myocardial perfusion in silent myocardial ischemia, we performed exercise stress myocardial tomography with thallium-201 (Tl) in 85 patients with coronary artery disease (CAD). Exercise stress myocardial tomography was obtained both immediately after exercise and three hours later. Patients were classified into two groups according to the presence (Symptomatic Group, n=36) or absence (Silent Group, n=49) of chest pain during exercise stress. Clinical features (age, gender and history of myocardial infarction) and arteriographically determined severity of CAD were the same in both groups. The extent of myocardial ischemia (% Ischemia) estimated by exercise stress myocardial tomography was the same in each group (30±10 % in Silent Group, 28±12 % in Symptomatic Group, NS). The severity of exercise-induced myocardial ischemia was expressed as a minimal value of myocardial Tl washout rate (minimal WOR) of each patient. Although exercise heart rate was identical in both groups, minimal WOR in Silent Group was significantly higher than that of Symptomatic Group (4±10% vs -16±14%, p<0.001). The study in patients who exhibited both silent and symptomatic ischemia showed the same results. These findings suggest that the severity of ischemia is a fundamental factor in determining the presence or absence of pain during exercise induced ischemia. (author)

  4. MR of experimental cerebral ischemia

    International Nuclear Information System (INIS)

    DeLaPaz, R.; Steinberg, G.; Rocklage, S.; Glover, G.H.

    1990-01-01

    This paper reports on MR imaging of cerebral ischemia and treatment with N-methyl-D-aspartate (NMDA) antagonists in an animal model. Forty-four New Zealand white rabbits underwent 1-hour transorbital ICA-MCA-ACA occlusion and pretreatment or immediate posttreatment with systemic dextromethorphan (DM, n = 14), dextrorphan (DX, n = 14), or normal saline (NS, n = 16). Serial MR studies (1.5 T) were performed 1--6 hours after occlusion with T1- and T2-weighted spinecho, IVIM (b = 1,352), gradient recalled acquisition in a steady-state, and chemical shift sequences (for magnetic susceptibility, T2* and T2') and DyDTPA-BMA intravenous contrast material (Salutar). Spatial correlation between MR findings, histologic findings (ischemic neuronal damage), and regional cerebral blood flow (microspheres) was done

  5. Leg ischemia post-varicocelectomy

    Directory of Open Access Journals (Sweden)

    Al-Wahbi AM

    2016-03-01

    Full Text Available Abdullah M Al-Wahbi1, Shaza Elmoukaied2 1Division of Vascular Surgery, Department of Surgery, King Abdulaziz Medical City, Riyadh, Saudi Arabia; 2Department of Surgery, Dr Sulaiman Al Habib Hospital, Riyadh, Saudi Arabia Abstract: Varicocelectomy is the most commonly performed operation for the treatment of male infertility. Many surgical approaches are used as each of them has advantages over the other and is preferred by surgeons. Vascular injury has never been reported as a complication of varicocelectomy apart from testicular artery injury. We present a 36-year-old male who developed leg ischemia post-varicocelectomy due to common femoral artery injury. He was successfully treated by using a vein graft. Keywords: varicocele, varicocelectomy, complications, vascular injuries

  6. Thalamic involvement in the regulation of alpha EEG activity in psychiatric patients

    International Nuclear Information System (INIS)

    Shirazi, S.P.; Pakula, J.; Young, I.J.; Crayton, J.W.; Konopka, L.M.; Rybak, M.

    2002-01-01

    Aim: The thalamus is considered to be an important sub-cortical system involved in modulation of cortical activities. A relationship between thalamic activity and surface EEG was recently reported. In this study we evaluated a group of patients with psychiatric disorders who presented with asymmetric perfusion of the thalamus based on brain SPECT HMPAO studies. We predicted that asymmetrical activity of the thalamus would have asymmetrically distributed surface qEEG activity patterns. Materials and Methods: Twenty-three male psychiatric patients (age 54±14) with a primary diagnosis of depression and co-morbid substance abuse (83%) were studied with qEEG and HMPAO brain SPECT. The HMPAO ligand was administered while the EEG activity was being recorded. The SPECT analysis was conducted by means of ROI and SPM. ROI regions were determined based on the Talairach atlas coordinate system. ROI locations were verified by the automated utility, Talairach Demon. QEEG data was analyzed by a standardized protocol involving the NxLink database. Correlations between SPECT findings and qEEG absolute power were calculated. Results: Patients were divided into two groups based on thalamic perfusion patterns. Group 1 (Gr 1) had decreased perfusion to the right thalamus whereas Group 2 (Gr 2) had decreased perfusion to the left thalamus. SPM comparison of the patient groups to normal control subjects indicated significant findings. Comparison of Gr 1 to controls showed increased activity in the left temporal lobe and vermis. Decreased activity was observed in the left and right medial frontal lobes (right Brodmann 9;left Brodmann 6) as well as the left (Brodmann 30) and right (Brodmann 24) cingulate. Gr 2 comparison showed increased activity in the right middle frontal gyrus (Brodmann 10) and left inferior parietal lobe. Decreased activity was found in the left inferior frontal lobe (Brodmann 47). A positive correlation between alpha power and thalamic perfusion was identified in Gr

  7. Cortically-controlled population stochastic facilitation as a plausible substrate for guiding sensory transfer across the thalamic gateway.

    Directory of Open Access Journals (Sweden)

    Sébastien Béhuret

    Full Text Available The thalamus is the primary gateway that relays sensory information to the cerebral cortex. While a single recipient cortical cell receives the convergence of many principal relay cells of the thalamus, each thalamic cell in turn integrates a dense and distributed synaptic feedback from the cortex. During sensory processing, the influence of this functional loop remains largely ignored. Using dynamic-clamp techniques in thalamic slices in vitro, we combined theoretical and experimental approaches to implement a realistic hybrid retino-thalamo-cortical pathway mixing biological cells and simulated circuits. The synaptic bombardment of cortical origin was mimicked through the injection of a stochastic mixture of excitatory and inhibitory conductances, resulting in a gradable correlation level of afferent activity shared by thalamic cells. The study of the impact of the simulated cortical input on the global retinocortical signal transfer efficiency revealed a novel control mechanism resulting from the collective resonance of all thalamic relay neurons. We show here that the transfer efficiency of sensory input transmission depends on three key features: i the number of thalamocortical cells involved in the many-to-one convergence from thalamus to cortex, ii the statistics of the corticothalamic synaptic bombardment and iii the level of correlation imposed between converging thalamic relay cells. In particular, our results demonstrate counterintuitively that the retinocortical signal transfer efficiency increases when the level of correlation across thalamic cells decreases. This suggests that the transfer efficiency of relay cells could be selectively amplified when they become simultaneously desynchronized by the cortical feedback. When applied to the intact brain, this network regulation mechanism could direct an attentional focus to specific thalamic subassemblies and select the appropriate input lines to the cortex according to the descending

  8. Therapeutic hypothermia reduces intestinal ischemia/reperfusion ...

    African Journals Online (AJOL)

    The detached intestinal epithelial cells in hypothermia group showed ... of apoptosis than those in normothermia group at 4 h (17.30 ± 2.56 vs. ... intestinal ischemia/reperfusion (IR) injury, which could be attenuated by therapeutic hypothermia.

  9. Motor and cortico-striatal-thalamic connectivity alterations in intrauterine growth restriction.

    Science.gov (United States)

    Eixarch, Elisenda; Muñoz-Moreno, Emma; Bargallo, Nuria; Batalle, Dafnis; Gratacos, Eduard

    2016-06-01

    Intrauterine growth restriction is associated with short- and long-term neurodevelopmental problems. Structural brain changes underlying these alterations have been described with the use of different magnetic resonance-based methods that include changes in whole structural brain networks. However, evaluation of specific brain circuits and its correlation with related functions has not been investigated in intrauterine growth restriction. In this study, we aimed to investigate differences in tractography-related metrics in cortico-striatal-thalamic and motor networks in intrauterine growth restricted children and whether these parameters were related with their specific function in order to explore its potential use as an imaging biomarker of altered neurodevelopment. We included a group of 24 intrauterine growth restriction subjects and 27 control subjects that were scanned at 1 year old; we acquired T1-weighted and 30 directions diffusion magnetic resonance images. Each subject brain was segmented in 93 regions with the use of anatomical automatic labeling atlas, and deterministic tractography was performed. Brain regions included in motor and cortico-striatal-thalamic networks were defined based in functional and anatomic criteria. Within the streamlines that resulted from the whole brain tractography, those belonging to each specific circuit were selected and tractography-related metrics that included number of streamlines, fractional anisotropy, and integrity were calculated for each network. We evaluated differences between both groups and further explored the correlation of these parameters with the results of socioemotional, cognitive, and motor scales from Bayley Scale at 2 years of age. Reduced fractional anisotropy (cortico-striatal-thalamic, 0.319 ± 0.018 vs 0.315 ± 0.015; P = .010; motor, 0.322 ± 0.019 vs 0.319 ± 0.020; P = .019) and integrity cortico-striatal-thalamic (0.407 ± 0.040 vs 0.399 ± 0.034; P = .018; motor, 0.417 ± 0.044 vs 0

  10. 201Tl myocardial SPECT and β-endorphin levels in patients with suspected silent ischemia

    International Nuclear Information System (INIS)

    Lind, P.; Binter, G.; Koeltringer, P.; Eber, O.; Eber, B.; Klein, W.; Brandt, D.

    1990-01-01

    Today silent myocardial ischemia (SMI) is a well-recognized phenomenon. Treadmill exercise according to the Bruce protocol, 201 Tl myocardial SPECT and coronary angiography were performed in a total of 106 patients with suspected SMI. In group I (high probability of ischemia; n=46), reversible defects detected by SPECT correlated well with significant stenoses and irreversible defects with subtotal stenoses or complete occlusions. SPECT sensitivity in the detection of ischemia was 91%, its specificity 96%. In group II (low probability of ischemia; n=60), SPECT sensitivity was as high as in group I (94%) but due to a high number of false-positive results (e.g. cardiomyopathy) specificity was only 75%. However, SPECT was superior to exercise ECG (sensitivity 70%; specificity 56%) in the detection of SMI. In addition, β-endorphin levels were determined in 180 healthy subjects, 37 patients with symptomatic CAD and in 34 patients with SMI before and during maximum exercise. Exercise values in patients with SMI were significantly higher than in healthy subjects or in patients with symptomatic CAD. (orig./MG) [de

  11. A computational relationship between thalamic sensory neural responses and contrast perception.

    Science.gov (United States)

    Jiang, Yaoguang; Purushothaman, Gopathy; Casagrande, Vivien A

    2015-01-01

    Uncovering the relationship between sensory neural responses and perceptual decisions remains a fundamental problem in neuroscience. Decades of experimental and modeling work in the sensory cortex have demonstrated that a perceptual decision pool is usually composed of tens to hundreds of neurons, the responses of which are significantly correlated not only with each other, but also with the behavioral choices of an animal. Few studies, however, have measured neural activity in the sensory thalamus of awake, behaving animals. Therefore, it remains unclear how many thalamic neurons are recruited and how the information from these neurons is pooled at subsequent cortical stages to form a perceptual decision. In a previous study we measured neural activity in the macaque lateral geniculate nucleus (LGN) during a two alternative forced choice (2AFC) contrast detection task, and found that single LGN neurons were significantly correlated with the monkeys' behavioral choices, despite their relatively poor contrast sensitivity and a lack of overall interneuronal correlations. We have now computationally tested a number of specific hypotheses relating these measured LGN neural responses to the contrast detection behavior of the animals. We modeled the perceptual decisions with different numbers of neurons and using a variety of pooling/readout strategies, and found that the most successful model consisted of about 50-200 LGN neurons, with individual neurons weighted differentially according to their signal-to-noise ratios (quantified as d-primes). These results supported the hypothesis that in contrast detection the perceptual decision pool consists of multiple thalamic neurons, and that the response fluctuations in these neurons can influence contrast perception, with the more sensitive thalamic neurons likely to exert a greater influence.

  12. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: application of a biomarker development strategy.

    Science.gov (United States)

    Barron, Daniel S; Fox, Peter T; Pardoe, Heath; Lancaster, Jack; Price, Larry R; Blackmon, Karen; Berry, Kristen; Cavazos, Jose E; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas

    2015-01-01

    Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.

  13. Thalamic metabolic alterations with cognitive dysfunction in idiopathic trigeminal neuralgia: a multivoxel spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuan; Bao, Faxiu; Ma, Shaohui; Guo, Chenguang; Jin, Chenwang; Zhang, Ming [First Affiliated Hospital of Xi' an Jiaotong University, Department of Medical Imaging, Xi' an, Shaanxi (China); Li, Dan [First Affiliated Hospital of Xi' an Jiaotong University, Department of Respiratory and Critical Care Medicine, Xi' an, Shaanxi (China)

    2014-08-15

    Although abnormalities in metabolite compositions in the thalamus are well described in patients with idiopathic trigeminal neuralgia (ITN), differences in distinct thalamic subregions have not been measured with proton magnetic resonance spectroscopy ({sup 1}H-MRS), and whether there are correlations between thalamic metabolites and cognitive function still remain unknown. Multivoxel MRS was recorded to investigate the metabolic alterations in the thalamic subregions of patients with ITN. The regions of interest were localized in the anterior thalamus (A-Th), intralaminar portion of the thalamus (IL-Th), posterior lateral thalamus (PL-Th), posterior medial thalamus (PM-Th), and medial and lateral pulvinar of the thalamus (PuM-Th and PuL-Th). The N-acetylaspartate to creatine (NAA/Cr) and choline to creatine (Cho/Cr) ratios were measured in the ITN and control groups. Scores of the visual analogue scale (VAS) and the Montreal Cognitive Assessment (MoCA) were analyzed to correlate with the neuroradiological findings. The NAA/Cr ratio in the affected side of PM-Th and PL-Th in ITN patients was statistically lower than that in the corresponding regions of the thalamus in controls. The NAA/Cr ratio in the affected PM-Th was negatively associated with VAS and disease duration. Furthermore, decreases of NAA/Cr and Cho/Cr were detected in the affected side of IL-Th, and lower Cho/Cr was positively correlated with MoCA values in the ITN group. Our result of low level of NAA/Cr in the affected PM-Th probably serves as a marker of the pain-rating index, and decreased Cho/Cr in IL-Th may be an indicator of cognitive disorder in patients with ITN. (orig.)

  14. Practical CT classification for thalamic hemorrhage. Relationship between localization of hematoma and prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Hiroki; Furuya, Kazuhide; Segawa, Hiromu; Taniguchi, Tamiki; Sano, Keiji [Fuji Brain Inst. and Hospital, Shizuoka (Japan); Shiokawa, Yoshiaki

    1994-06-01

    The study was designed to establish CT classification for predicting prognosis of thalamic hemorrhage. A retrospective analysis was made on CT scans from 100 patients with hypertensive thalamic hemorrhage less than 4 cm. Four lines were drawn on axial CT scans at the level of the pineal body: (A) line between the lateral edge of the anterior horn and the midpoint of the third ventricle; (B) vertebral line to the sagittal line from the midpoint of the third ventricle; (C) line between the lateral edge of the trigone and the midpoint of the third ventricle; and (D) line between the lateral edge of the anterior horn and the lateral edge of the trigone. According to the lateral extension, the location of hematoma fell into three types: anterior type in which the center of hematoma was located between lines A and B (type A); posterior type in which the center of hematoma was located between lines B and C and external margin of hematoma was localized medial to line D (type P); postero-lateral type in which the center of hematoma was located between lines B and C and showed lateral extension beyond line D (type PL). Severe hemiparesis was observed in 15.3% for type A, 21.8% for type P, and 59.3% for type PL. Good prognosis was seen in 84.7% for type A, 70.9% for type P, and 12.5% for type PL. Acute disturbance of consciousness was significantly observed in patients with medial extension of hematoma (86.4%) as compared with those without it (21.4%). These results indicated that CT classification is a simple means for predicting functional outcome of motor paresis and consciousness disturbance in patients with thalamic hemorrhage. (N.K.).

  15. Practical CT classification for thalamic hemorrhage. Relationship between localization of hematoma and prognosis

    International Nuclear Information System (INIS)

    Kurita, Hiroki; Furuya, Kazuhide; Segawa, Hiromu; Taniguchi, Tamiki; Sano, Keiji; Shiokawa, Yoshiaki.

    1994-01-01

    The study was designed to establish CT classification for predicting prognosis of thalamic hemorrhage. A retrospective analysis was made on CT scans from 100 patients with hypertensive thalamic hemorrhage less than 4 cm. Four lines were drawn on axial CT scans at the level of the pineal body: (A) line between the lateral edge of the anterior horn and the midpoint of the third ventricle; (B) vertebral line to the sagittal line from the midpoint of the third ventricle; (C) line between the lateral edge of the trigone and the midpoint of the third ventricle; and (D) line between the lateral edge of the anterior horn and the lateral edge of the trigone. According to the lateral extension, the location of hematoma fell into three types: anterior type in which the center of hematoma was located between lines A and B (type A); posterior type in which the center of hematoma was located between lines B and C and external margin of hematoma was localized medial to line D (type P); postero-lateral type in which the center of hematoma was located between lines B and C and showed lateral extension beyond line D (type PL). Severe hemiparesis was observed in 15.3% for type A, 21.8% for type P, and 59.3% for type PL. Good prognosis was seen in 84.7% for type A, 70.9% for type P, and 12.5% for type PL. Acute disturbance of consciousness was significantly observed in patients with medial extension of hematoma (86.4%) as compared with those without it (21.4%). These results indicated that CT classification is a simple means for predicting functional outcome of motor paresis and consciousness disturbance in patients with thalamic hemorrhage. (N.K.)

  16. Clinical Features and Outcomes of Gastric Ischemia.

    Science.gov (United States)

    Sharma, Ayush; Mukewar, Saurabh; Chari, Suresh T; Wong Kee Song, Louis M

    2017-12-01

    Gastric ischemia is a rare condition associated with poor prognosis. Our study aim was to highlight the clinical features and outcomes of patients with gastric ischemia. A retrospective review of patients diagnosed with isolated gastric ischemia at our institution from January 1, 2000, to May 5, 2016, was performed. Demographic, clinical, endoscopic, radiologic, and outcome variables were abstracted for analysis. Seventeen patients (65% men) with mean age of 69.3 ± 11.3 years and body mass index of 28.8 ± 11.1 were identified. The etiologies for gastric ischemia included local vascular causes (n = 8), systemic hypoperfusion (n = 4), and mechanical obstruction (n = 5). The most common presenting symptoms were abdominal pain (65%), gastrointestinal bleeding (47%), and altered mental status (23%). The typical endoscopic appearance was mucosal congestion and erythema with or without ulceration. Gastric pneumatosis and portal venous air were more commonly seen on CT imaging. Radiologic and/or surgical intervention was needed in 9 patients, while the remaining 8 patients were managed conservatively with acid suppression, antibiotics, and nasogastric tube decompression. The median duration of hospital stay was 15 days (range 1-36 days). There were no cases of rebleeding and the mortality rate as a direct result of gastric ischemia was 24% within 6 months of diagnosis. Although uncommon, gastric ischemia is associated with significant mortality. Endoscopy and CT imaging play an important role in its diagnosis. The management of gastric ischemia is dictated by its severity and associated comorbidities.

  17. Regional thalamic neuropathology in patients with hippocampal sclerosis and epilepsy: A postmortem study

    Science.gov (United States)

    Sinjab, Barah; Martinian, Lillian; Sisodiya, Sanjay M; Thom, Maria

    2013-01-01

    Purpose Clinical, experimental, and neuroimaging data all indicate that the thalamus is involved in the network of changes associated with temporal lobe epilepsy (TLE), particularly in association with hippocampal sclerosis (HS), with potential roles in seizure initiation and propagation. Pathologic changes in the thalamus may be a result of an initial insult, ongoing seizures, or retrograde degeneration through reciprocal connections between thalamic and limbic regions. Our aim was to carry out a neuropathologic analysis of the thalamus in a postmortem (PM) epilepsy series, to assess the distribution, severity, and nature of pathologic changes and its association with HS. Methods Twenty-four epilepsy PM cases (age range 25–87 years) and eight controls (age range 38–85 years) were studied. HS was classified as unilateral (UHS, 11 cases), bilateral (BHS, 4 cases) or absent (No-HS, 9 cases). Samples from the left and right sides of the thalamus were stained with cresyl violet (CV), and for glial firbillary acidic protein (GFAP) and synaptophysin. Using image analysis, neuronal densities (NDs) or field fraction staining values (GFAP, synaptophysin) were measured in four thalamic nuclei: anteroventral nucleus (AV), lateral dorsal nucleus (LD), mediodorsal nucleus (MD), and ventrolateral nucleus (VL). The results were compared within and between cases. Key Findings The severity, nature, and distribution of thalamic pathology varied between cases. A pattern that emerged was a preferential involvement of the MD in UHS cases with a reduction in mean ND ipsilateral to the side of HS (p = 0.05). In UHS cases, greater field fraction values for GFAP and lower values for synaptophysin and ND were seen in the majority of cases in the MD ipsilateral to the side of sclerosis compared to other thalamic nuclei. In addition, differences in the mean ND between classical HS, atypical HS, and No-HS cases were noted in the ipsilateral MD (p < 0.05), with lower values observed in

  18. Capsular and thalamic infarction caused by tentorial herniation subsequent to head trauma

    International Nuclear Information System (INIS)

    Endo, M.; Ichikawa, F.; Miyasaka, Y.; Yada, K.; Ohwada, T.

    1991-01-01

    Five patients (4 male and 1 female) were observed to have capsular and thalamic infarction ascribed to descending transtentorial herniation (DTH) caused by head injury. A lucid interval immediately after the trauma and the presence of an epidural hematoma (EDH) characterized all five case. The low attenuation implicated the perforating arteries, that is the anterior thalamoperforating and anterior choroidal arteries, suggesting infarcted regions caused by occlusion of these arteries. Findings in the present study suggest that arterial occlusion in closed head injury may result from DTH. Moreover, infarction may be attributed to the delayed effects of injury. (orig./GDG)

  19. Thalamic Massa Intermedia Duplication in a Dysmorphic 14 month-old Toddler.

    Science.gov (United States)

    Whitehead, Matthew T

    2015-06-01

    The massa intermedia is an inconstant parenchymal band connecting the medial thalami. It may be thickened in various disease processes such as Chiari II malformation or absent in other disease states. However, the massa intermedia may also be absent in up to 30% of normal human brains. To the best of my knowledge, detailed imaging findings of massa intermedia duplication have only been described in a single case report. An additional case of thalamic massa intermedia duplication discovered on a routine brain MR performed for dysmorphic facial features is reported herein.

  20. Reversible Statistics

    DEFF Research Database (Denmark)

    Tryggestad, Kjell

    2004-01-01

    The study aims is to describe how the inclusion and exclusion of materials and calculative devices construct the boundaries and distinctions between statistical facts and artifacts in economics. My methodological approach is inspired by John Graunt's (1667) Political arithmetic and more recent work...... within constructivism and the field of Science and Technology Studies (STS). The result of this approach is here termed reversible statistics, reconstructing the findings of a statistical study within economics in three different ways. It is argued that all three accounts are quite normal, albeit...... in different ways. The presence and absence of diverse materials, both natural and political, is what distinguishes them from each other. Arguments are presented for a more symmetric relation between the scientific statistical text and the reader. I will argue that a more symmetric relation can be achieved...

  1. Diagnostic value of exercise induced 18F-FDG myocardial metabolism scintigraphy in myocardial ischemia

    International Nuclear Information System (INIS)

    Shen Rui; He Zuoxiang; Shi Rongfang; Liu Xiujie; Tian Yueqin; Guo Feng; Wei Hongxing; Wu Yongjian; Qin Xuewen; Gao Runlin

    2006-01-01

    Objective: To evaluate the feasibility and diagnostic accuracy of exercise induced myocardial imaging with 18 F-fluorodeoxyglucose (FDG) in myocardial ischemia. Methods: Twenty-six patients with known or suspected coronary artery, disease (CAD) and with no prior myocardial infarction underwent simultaneous myocardial perfusion and metabolism imaging following intravenous injection of 99 Tc m -methoxy-isobutylisonitrile ( 99 Tc m -sestamibi) and 18 F-FDG at peak exercise. Subsequently rest perfusion imaging and coronary angiography (CAG) were performed in all patients. Exercise 18 F-FDG myocardial imaging was compared with 99 Tc m -sestamibi imaging and CAG. Results: In 22 patients with ≥50% narrowing over l coronary artery, 18 had perfusion abnormalities (sensitivity 82%), whereas 20 had abnormal myocardial 18 F-FDG uptake (sensitivity 91%, P>0.05). Patients with reversible (12 cases) or partial reversible (3 cases) perfusion abnormalities had increased myocardial 18 F-FDG uptake in abnormal perfusion segments. Compared with CAG, perfusion defect was seen in myocardial segments corresponding to 25 vascular territories of 51 vessels with ≥50% narrowing in 22 patients in 99 Tc m -sestamibi imaging (sensitivity 49%), whereas increased 18 F-FDG uptake was seen in 34 vascular territories (sensitivity 67%, P=0.008). Conclusions: Exercise induced myocardial ischemia can be imaged directly with 18 F-FDG. Combined exercise 18 F-FDG and 99 Tc m -sestamibi imaging provides a better assessment of exercise-induced myocardial ischemia as compared with exercise-rest perfusion imaging. (authors)

  2. Omega-3 Fatty Acids: Possible Neuroprotective Mechanisms in the Model of Global Ischemia in Rats

    Directory of Open Access Journals (Sweden)

    Maria Elizabeth Pereira Nobre

    2016-01-01

    Full Text Available Background. Omega-3 (ω3 administration was shown to protect against hypoxic-ischemic injury. The objectives were to study the neuroprotective effects of ω3, in a model of global ischemia. Methods. Male Wistar rats were subjected to carotid occlusion (30 min, followed by reperfusion. The groups were SO, untreated ischemic and ischemic treated rats with ω3 (5 and 10 mg/kg, 7 days. The SO and untreated ischemic animals were orally treated with 1% cremophor and, 1 h after the last administration, they were behaviorally tested and euthanized for neurochemical (DA, DOPAC, and NE determinations, histological (Fluoro jade staining, and immunohistochemical (TNF-alpha, COX-2 and iNOS evaluations. The data were analyzed by ANOVA and Newman-Keuls as the post hoc test. Results. Ischemia increased the locomotor activity and rearing behavior that were partly reversed by ω3. Ischemia decreased striatal DA and DOPAC contents and increased NE contents, effects reversed by ω3. This drug protected hippocampal neuron degeneration, as observed by Fluoro-Jade staining, and the increased immunostainings for TNF-alpha, COX-2, and iNOS were partly or totally blocked by ω3. Conclusion. This study showed a neuroprotective effect of ω3, in great part due to its anti-inflammatory properties, stimulating translational studies focusing on its use in clinic for stroke managing.

  3. Anterior Thalamic High Frequency Band Activity Is Coupled with Theta Oscillations at Rest

    Directory of Open Access Journals (Sweden)

    Catherine M. Sweeney-Reed

    2017-07-01

    Full Text Available Cross-frequency coupling (CFC between slow and fast brain rhythms, in the form of phase–amplitude coupling (PAC, is proposed to enable the coordination of neural oscillatory activity required for cognitive processing. PAC has been identified in the neocortex and mesial temporal regions, varying according to the cognitive task being performed and also at rest. PAC has also been observed in the anterior thalamic nucleus (ATN during memory processing. The thalamus is active during the resting state and has been proposed to be involved in switching between task-free cognitive states such as rest, in which attention is internally-focused, and externally-focused cognitive states, in which an individual engages with environmental stimuli. It is unknown whether PAC is an ongoing phenomenon during the resting state in the ATN, which is modulated during different cognitive states, or whether it only arises during the performance of specific tasks. We analyzed electrophysiological recordings of ATN activity during rest from seven patients who received thalamic electrodes implanted for treatment of pharmacoresistant focal epilepsy. PAC was identified between theta (4–6 Hz phase and high frequency band (80–150 Hz amplitude during rest in all seven patients, which diminished during engagement in tasks involving an external focus of attention. The findings are consistent with the proposal that theta–gamma coupling in the ATN is an ongoing phenomenon, which is modulated by task performance.

  4. Feedforward inhibitory control of sensory information in higher-order thalamic nuclei.

    Science.gov (United States)

    Lavallée, Philippe; Urbain, Nadia; Dufresne, Caroline; Bokor, Hajnalka; Acsády, László; Deschênes, Martin

    2005-08-17

    Sensory stimuli evoke strong responses in thalamic relay cells, which ensure a faithful relay of information to the neocortex. However, relay cells of the posterior thalamic nuclear group in rodents, despite receiving significant trigeminal input, respond poorly to vibrissa deflection. Here we show that sensory transmission in this nucleus is impeded by fast feedforward inhibition mediated by GABAergic neurons of the zona incerta. Intracellular recordings of posterior group neurons revealed that the first synaptic event after whisker deflection is a prominent inhibition. Whisker-evoked EPSPs with fast rise time and longer onset latency are unveiled only after lesioning the zona incerta. Excitation survives barrel cortex lesion, demonstrating its peripheral origin. Electron microscopic data confirm that trigeminal axons make large synaptic terminals on the proximal dendrites of posterior group cells and on the somata of incertal neurons. Thus, the connectivity of the system allows an unusual situation in which inhibition precedes ascending excitation resulting in efficient shunting of the responses. The dominance of inhibition over excitation strongly suggests that the paralemniscal pathway is not designed to relay inputs triggered by passive whisker deflection. Instead, we propose that this pathway operates through disinhibition, and that the posterior group forwards to the cerebral cortex sensory information that is contingent on motor instructions.

  5. Deafferentation in thalamic and pontine areas in severe traumatic brain injury.

    Science.gov (United States)

    Laouchedi, M; Galanaud, D; Delmaire, C; Fernandez-Vidal, S; Messé, A; Mesmoudi, S; Oulebsir Boumghar, F; Pélégrini-Issac, M; Puybasset, L; Benali, H; Perlbarg, V

    2015-07-01

    Severe traumatic brain injury (TBI) is characterized mainly by diffuse axonal injuries (DAI). The cortico-subcortical disconnections induced by such fiber disruption play a central role in consciousness recovery. We hypothesized that these cortico-subcortical deafferentations inferred from diffusion MRI data could differentiate between TBI patients with favorable or unfavorable (death, vegetative state, or minimally conscious state) outcome one year after injury. Cortico-subcortical fiber density maps were derived by using probabilistic tractography from diffusion tensor imaging data acquired in 24 severe TBI patients and 9 healthy controls. These maps were compared between patients and controls as well as between patients with favorable (FO) and unfavorable (UFO) 1-year outcome to identify the thalamo-cortical and ponto-thalamo-cortical pathways involved in the maintenance of consciousness. Thalamo-cortical and ponto-thalamo-cortical fiber density was significantly lower in TBI patients than in healthy controls. Comparing FO and UFO TBI patients showed thalamo-cortical deafferentation associated with unfavorable outcome for projections from ventral posterior and intermediate thalamic nuclei to the associative frontal, sensorimotor and associative temporal cortices. Specific ponto-thalamic deafferentation in projections from the upper dorsal pons (including the reticular formation) was also associated with unfavorable outcome. Fiber density of cortico-subcortical pathways as measured from diffusion MRI tractography is a relevant candidate biomarker for early prediction of one-year favorable outcome in severe TBI. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. Sleep spindles are related to schizotypal personality traits and thalamic glutamine/glutamate in healthy subjects.

    Science.gov (United States)

    Lustenberger, Caroline; O'Gorman, Ruth L; Pugin, Fiona; Tüshaus, Laura; Wehrle, Flavia; Achermann, Peter; Huber, Reto

    2015-03-01

    Schizophrenia is a severe mental disorder affecting approximately 1% of the worldwide population. Yet, schizophrenia-like experiences (schizotypy) are very common in the healthy population, indicating a continuum between normal mental functioning and the psychosis found in schizophrenic patients. A continuum between schizotypy and schizophrenia would be supported if they share the same neurobiological origin. Two such neurobiological markers of schizophrenia are: (1) a reduction of sleep spindles (12-15 Hz oscillations during nonrapid eye movement sleep), likely reflecting deficits in thalamo-cortical circuits and (2) increased glutamine and glutamate (Glx) levels in the thalamus. Thus, this study aimed to investigate whether sleep spindles and Glx levels are related to schizotypal personality traits in healthy subjects. Twenty young male subjects underwent 2 all-night sleep electroencephalography recordings (128 electrodes). Sleep spindles were detected automatically. After those 2 nights, thalamic Glx levels were measured by magnetic resonance spectroscopy. Subjects completed a magical ideation scale to assess schizotypy. Sleep spindle density was negatively correlated with magical ideation (r = -.64, P .1). The common relationship of sleep spindle density with schizotypy and thalamic Glx levels indicates a neurobiological overlap between nonclinical schizotypy and schizophrenia. Thus, sleep spindle density and magical ideation may reflect the anatomy and efficiency of the thalamo-cortical system that shows pronounced impairment in patients with schizophrenia. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Central thalamic deep brain stimulation for support of forebrain arousal regulation in the minimally conscious state.

    Science.gov (United States)

    Schiff, Nicholas D

    2013-01-01

    This chapter considers the use of central thalamic deep brain stimulation (CT/DBS) to support arousal regulation mechanisms in the minimally conscious state (MCS). CT/DBS for selected patients in a MCS is first placed in the historical context of prior efforts to use thalamic electrical brain stimulation to treat the unconscious clinical conditions of coma and vegetative state. These previous studies and a proof of concept result from a single-subject study of a patient in a MCS are reviewed against the background of new population data providing benchmarks of the natural history of vegetative and MCSs. The conceptual foundations for CT/DBS in selected patients in a MCS are then presented with consideration of both circuit and cellular mechanisms underlying recovery of consciousness identified from empirical studies. Directions for developing future generalizable criteria for CT/DBS that focus on the integrity of necessary brain systems and behavioral profiles in patients in a MCS that may optimally response to support of arousal regulation mechanisms are proposed. © 2013 Elsevier B.V. All rights reserved.

  8. Clinical appraisal of stereotactic hematoma aspiration surgery for hypertensive thalamic hemorrhage

    International Nuclear Information System (INIS)

    Sasaki, Koji; Matsumoto, Keizo

    1992-01-01

    Three hundred and four patients with hypertensive thalamic hemorrhage were managed by medical treatment, ventricular drainage, or CT-controlled stereotactic aspiration surgery (AS). The therapeutic results of the 6-month outcome were analyzed and correlated with the volume of the hematoma. A hematoma volume of 20 ml was thought to be the critical size in determining whether the outcome would be favorable or unfavorable. Indications for AS are suggested as follows. In patients with a small-sized hematoma having a volume of less than 10 ml use of AS should be restricted to patients with severe paralysis or other neurological complications and the elderly (aged 70 years or older). For patients with a medium-sized hematoma having a volume between 10 ml and 20 ml, AS is indicated for patients having severe paralysis and disturbances of consciousness. For patients with a large-sized hematoma having a volume of 20 ml or more, AS increases not only the survival rate of patients but also reduces the number of bedridden patients. We conclude that AS opens up a new avenue of surgical treatment for hypertensive thalamic hemorrhage, which has been no indication for hematoma evacuation by conventional craniotomy. (author)

  9. Human Thalamic-Prefrontal Peduncle Connectivity Revealed by Diffusion Spectrum Imaging Fiber Tracking

    Directory of Open Access Journals (Sweden)

    Chuanqi Sun

    2018-04-01

    Full Text Available The thalamic-prefrontal peduncle (TPP is a large bundle connecting the thalamus and prefrontal cortex. The definitive structure and function of the TPP are still controversial. To investigate the connectivity and segmentation patterns of the TPP, we employed diffusion spectrum imaging with generalized q-sampling reconstruction to perform both subject-specific and template-based analyses. Our results confirmed the trajectory and spatial relationship of the TPP in the human brain and identified the connection areas in the prefrontal cortex. The TPP-connecting areas identified based on Brodmann areas (BAs were BAs 8–11 and 45–47. Based on the automated anatomical atlas, these areas were the medial superior frontal gyrus, superior frontal gyrus, middle frontal gyrus, pars triangularis, pars orbitalis, anterior orbital gyrus, and lateral orbital gyrus. In addition, we identified the TPP connection areas in the thalamus, including the anterior and medial nuclei, and the lateral dorsal/lateral posterior nuclei. TPP fibers connected the thalamus with the ipsilateral prefrontal BAs 11, 47, 10, 46, 45, 9, and 8 seriatim from medial to lateral, layer by layer. Our results provide further details of the thalamic-prefrontal peduncle structure, and may aid future studies and a better understanding of the functional roles of the TPP in the human brain.

  10. Case of herpes simplex encephalitis(HSE) with a thalamic lesion

    Energy Technology Data Exchange (ETDEWEB)

    Fujimori, K; Koike, R; Yuasa, T; Miyatake, T; Ito, J

    1987-02-01

    A case of herpes simplex encephalitis (HSE) with thalamic involvement was reported. The patient, a 27-year-old man, was admitted because of abnormal behavior and fever. He exhibited a disturbance of consciousness, meningial signs, and hyperreflexia. A CT scan of the head revealed diffuse brain edema. Acute encephalitis, especially HSE, was suspected, and so the intravenous administration of acyclovir and steroid therapy were started. The titer of herpes simplex Type 1 virus, as measured by CF and ELISA, was found to have increased amounts of serum and cerebrospinal fluid. 5 days after the onset, his consciousness worsened. He could not tell his name and scarely opened his eyes upon pain stimulation. A CT scan at this time showed low-density lesions in the left thalamus, cingulate gyrus, and the posterior portion of the putamen. About 5 days later, his consciousness level was increased, but he was mute. This symptom was thought to be thalamic aphasia, which might be correlative with the low-density lesions shown in the left thalamus by the CT scan. About 30 days after the onset of the disease, his speech became normal, and a CT scan at 51 hospital days showed no abnormality. The etiology of low-density lesions of the left thalamus in the CT scan is speculated to be as follows: firstly, vascular damage of circulation disturbance, and secondly a special affinity of herpes simplex Type 1 virus to the thalamus.

  11. Persistence of disturbed thalamic glucose metabolism in a case of Wernicke-Korsakoff syndrome.

    Science.gov (United States)

    Fellgiebel, Andreas; Scheurich, Armin; Siessmeier, Thomas; Schmidt, Lutz G; Bartenstein, Peter

    2003-10-30

    We report the case of a 40-year-old alcoholic male patient, hospitalized with an acute ataxia of stance and gait, ocular muscle weakness with nystagmus and a global apathetic-confusional state. After admission, an amnestic syndrome with confabulation was also observed and diagnosis of Wernicke-Korsakoff syndrome was made. Under treatment with intravenous thiamine, the patient recovered completely from gaze weakness and ataxia, whereas a severe amnestic syndrome persisted. Fluorodeoxyglucose (FDG) positron emission tomography (PET) showed bilateral thalamic and severe bilateral temporal-parietal hypometabolism resembling a pattern typical for Alzheimer's disease. Longitudinal assessment of the alcohol-abstinent and thiamine-substituted patient revealed improvements of clinical state and neuropsychological performance that were paralleled by recovered cerebral glucose metabolism. In contrast to metabolic rates that increased between 7.1% (anterior cingulate, left) and 23.5% (parietal, left) in cortical areas during a 9-month remission period, thalamic glucose metabolism remained severely disturbed over time (change: left +0.2%, right +0.3%).

  12. Thalamic synaptic transmission of sensory information modulated by synergistic interaction of adenosine and serotonin.

    Science.gov (United States)

    Yang, Ya-Chin; Hu, Chun-Chang; Huang, Chen-Syuan; Chou, Pei-Yu

    2014-03-01

    The thalamic synapses relay peripheral sensory information to the cortex, and constitute an important part of the thalamocortical network that generates oscillatory activities responsible for different vigilance (sleep and wakefulness) states. However, the modulation of thalamic synaptic transmission by potential sleep regulators, especially by combination of regulators in physiological scenarios, is not fully characterized. We found that somnogen adenosine itself acts similar to wake-promoting serotonin, both decreasing synaptic strength as well as short-term depression, at the retinothalamic synapse. We then combined the two modulators considering the coexistence of them in the hypnagogic (sleep-onset) state. Adenosine plus serotonin results in robust synergistic inhibition of synaptic strength and dramatic transformation of short-term synaptic depression to facilitation. These synaptic effects are not achievable with a single modulator, and are consistent with a high signal-to-noise ratio but a low level of signal transmission through the thalamus appropriate for slow-wave sleep. This study for the first time demonstrates that the sleep-regulatory modulators may work differently when present in combination than present singly in terms of shaping information flow in the thalamocortical network. The major synaptic characters such as the strength and short-term plasticity can be profoundly altered by combination of modulators based on physiological considerations. © 2013 International Society for Neurochemistry.

  13. A case of herpes simplex encephalitis(HSE) with a thalamic lesion

    International Nuclear Information System (INIS)

    Fujimori, Katsuya; Koike, Ryoko; Yuasa, Tatsuhiko; Miyatake, Tadashi; Ito, Jusuke.

    1987-01-01

    A case of herpes simplex encephalitis (HSE) with thalamic involvement was reported. The patient, a 27-year-old man, was admitted because of abnormal behavior and fever. He exhibited a disturbance of consciousness, meningial signs, and hyperreflexia. A CT scan of the head revealed diffuse brain edema. Acute encephalitis, especially HSE, was suspected, and so the intravenous administration of acyclovir and steroid therapy were started. The titer of herpes simplex Type 1 virus, as measured by CF and ELISA, was found to have increased amounts of serum and cerebrospinal fluid. 5 days after the onset, his consciousness worsened. He could not tell his name and scarely opened his eyes upon pain stimulation. A CT scan at this time showed low-density lesions in the left thalamus, cingulate gyrus, and the posterior portion of the putamen. About 5 days later, his consciousness level was increased, but he was mute. This symptom was thought to be thalamic aphasia, which might be correlative with the low-density lesions shown in the left thalamus by the CT scan. About 30 days after the onset of the disease, his speech became normal, and a CT scan at 51 hospital days showed no abnormality. The etiology of low-density lesions of the left thalamus in the CT scan is speculated to be as follows: firstly, vascular damage of circulation disturbance, and secondly a special affinity of herpes simplex Type 1 virus to the thalamus. (author)

  14. Dynamics of action potential initiation in the GABAergic thalamic reticular nucleus in vivo.

    Science.gov (United States)

    Muñoz, Fabián; Fuentealba, Pablo

    2012-01-01

    Understanding the neural mechanisms of action potential generation is critical to establish the way neural circuits generate and coordinate activity. Accordingly, we investigated the dynamics of action potential initiation in the GABAergic thalamic reticular nucleus (TRN) using in vivo intracellular recordings in cats in order to preserve anatomically-intact axo-dendritic distributions and naturally-occurring spatiotemporal patterns of synaptic activity in this structure that regulates the thalamic relay to neocortex. We found a wide operational range of voltage thresholds for action potentials, mostly due to intrinsic voltage-gated conductances and not synaptic activity driven by network oscillations. Varying levels of synchronous synaptic inputs produced fast rates of membrane potential depolarization preceding the action potential onset that were associated with lower thresholds and increased excitability, consistent with TRN neurons performing as coincidence detectors. On the other hand the presence of action potentials preceding any given spike was associated with more depolarized thresholds. The phase-plane trajectory of the action potential showed somato-dendritic propagation, but no obvious axon initial segment component, prominent in other neuronal classes and allegedly responsible for the high onset speed. Overall, our results suggest that TRN neurons could flexibly integrate synaptic inputs to discharge action potentials over wide voltage ranges, and perform as coincidence detectors and temporal integrators, supported by a dynamic action potential threshold.

  15. Magnetic resonance spectroscopy and imaging in cerebral ischemia

    International Nuclear Information System (INIS)

    Rijen, P.C. van.

    1991-01-01

    In-vivo proton and phosphorus magnetic resonance spectroscopy was used to detect changes in cerebral metabolism during ischemia and other types of metabolic stress. Magnetic resonance imaging was performed in an animal model to observe morphological alterations during focal cerebral ischemia. Spectroscopy was performed in animal models with global ischemia, in volunteers during hyperventilation and pharmaco-logically altered cerebral perfusion, and in patients with acute and prolonged focal cerebral ischemia. (author). 396 refs.; 44 figs.; 14 tabs

  16. Postcircumcisional Ischemia of the Glans Penis Treated with Pentoxifylline

    Directory of Open Access Journals (Sweden)

    Ersagun Karaguzel

    2013-01-01

    Full Text Available Ischemia of the glans penis is a rare postcircumcision complication. We describe a four-year-old boy developing ischemia of the glans penis 48 h after circumcision. The ischemia completely resolved following treatment with iv pentoxifylline (PTX for six days, and the patient was discharged without any problems. PTX treatment should be kept in mind as an alternative treatment modality in ischemia of the glans penis which is a serious potential post-circumcision complication.

  17. Role of phosphoinositide 3-kinase in ischemic postconditioning-induced attenuation of cerebral ischemia-evoked behavioral deficits in mice.

    Science.gov (United States)

    Rehni, Ashish K; Singh, Nirmal

    2007-01-01

    The present study has been designed to pharmacologically investigate the role of phosphoinositide 3-kinase in ischemic postconditioning-induced reversal of global cerebral ischemia and reperfusion-induced behavioral dysfunction in mice. Bilateral carotid artery occlusion for 10 min followed by reperfusion for 24 h was employed in the present study to produce ischemia and reperfusion-induced cerebral injury in mice. Short-term memory was evaluated using the elevated plus maze test. The inclined beam walking test was employed to assess motor incoordination. Bilateral carotid artery occlusion followed by reperfusion produced impaired short-term memory, motor co-ordination and lateral push response. Three episodes of carotid artery occlusion for a period of 10 s and reperfusion of 10 s (ischemic postconditioning) significantly prevented ischemia-reperfusion-induced behavioral deficit measured in terms of loss of short-term memory, motor coordination and lateral push response. Wortmannin (2 mg/kg, iv), a phosphoinositide 3-kinase inhibitor given 10 min before ischemia attenuated the beneficial effects of ischemic postconditioning. It may be concluded that beneficial effects of ischemic postconditioning on global cerebral ischemia and reperfusion-induced behavioral deficits may involve activation of phosphoinositide 3-kinase-linked pathway.

  18. Metallothionein-II Inhibits Lipid Peroxidation and Improves Functional Recovery after Transient Brain Ischemia and Reperfusion in Rats

    Directory of Open Access Journals (Sweden)

    Araceli Diaz-Ruiz

    2014-01-01

    Full Text Available After transient cerebral ischemia and reperfusion (I/R, damaging mechanisms, such as excitotoxicity and oxidative stress, lead to irreversible neurological deficits. The induction of metallothionein-II (MT-II protein is an endogenous mechanism after I/R. Our aim was to evaluate the neuroprotective effect of MT-II after I/R in rats. Male Wistar rats were transiently occluded at the middle cerebral artery for 2 h, followed by reperfusion. Rats received either MT (10 μg per rat i.p. or vehicle after ischemia. Lipid peroxidation (LP was measured 22 h after reperfusion in frontal cortex and hippocampus; also, neurological deficit was evaluated after ischemia, using the Longa scoring scale. Infarction area was analyzed 72 hours after ischemia. Results showed increased LP in frontal cortex (30.7% and hippocampus (26.4%, as compared to control group; this effect was fully reversed by MT treatment. Likewise, we also observed a diminished neurological deficit assessed by the Longa scale in those animals treated with MT compared to control group values. The MT-treated group showed a significant (P<0.05 reduction of 39.9% in the infarction area, only at the level of hippocampus, as compared to control group. Results suggest that MT-II may be a novel neuroprotective treatment to prevent ischemia injury.

  19. Intraoperative neurophysiological responses in epileptic patients submitted to hippocampal and thalamic deep brain stimulation.

    Science.gov (United States)

    Cukiert, Arthur; Cukiert, Cristine Mella; Argentoni-Baldochi, Meire; Baise, Carla; Forster, Cássio Roberto; Mello, Valeria Antakli; Burattini, José Augusto; Lima, Alessandra Moura

    2011-12-01

    Deep brain stimulation (DBS) has been used in an increasing frequency for treatment of refractory epilepsy. Acute deep brain macrostimulation intraoperative findings were sparsely published in the literature. We report on our intraoperative macrostimulation findings during thalamic and hippocampal DBS implantation. Eighteen patients were studied. All patients underwent routine pre-operative evaluation that included clinical history, neurological examination, interictal and ictal EEG, high resolution 1.5T MRI and neuropsychological testing. Six patients with temporal lobe epilepsy were submitted to hippocampal DBS (Hip-DBS); 6 patients with focal epilepsy were submitted to anterior thalamic nucleus DBS (AN-DBS) and 6 patients with generalized epilepsy were submitted to centro-median thalamic nucleus DBS (CM-DBS). Age ranged from 9 to 40 years (11 males). All patients were submitted to bilateral quadripolar DBS electrode implantation in a single procedure, under general anesthesia, and intraoperative scalp EEG monitoring. Final electrode's position was checked postoperatively using volumetric CT scanning. Bipolar stimulation using the more proximal and distal electrodes was performed. Final standard stimulation parameters were 6Hz, 4V, 300μs (low frequency range: LF) or 130Hz, 4V, 300μs (high frequency range: HF). Bilateral recruiting response (RR) was obtained after unilateral stimulation in all patients submitted to AN and CM-DBS using LF stimulation. RR was widespread but prevailed over the fronto-temporal region bilaterally, and over the stimulated hemisphere. HF stimulation led to background slowing and a DC shift. The mean voltage for the appearance of RR was 4V (CM) and 3V (AN). CM and AN-DBS did not alter inter-ictal spiking frequency or morphology. RR obtained after LF Hip-DBS was restricted to the stimulated temporal lobe and no contralateral activation was noted. HF stimulation yielded no visually recognizable EEG modification. Mean intensity for initial

  20. Endogenous developmental endothelial locus-1 limits ischemia-related angiogenesis by blocking inflammation

    Science.gov (United States)

    Klotzsche - von Ameln, Anne; Cremer, Sebastian; Hoffmann, Jedrzej; Schuster, Peggy; Khedr, Sherif; Korovina, Irina; Troulinaki, Maria; Neuwirth, Ales; Sprott, David; Chatzigeorgiou, Antonios; Economopoulou, Matina; Orlandi, Alessia; Hain, Andreas; Zeiher, Andreas M.; Deussen, Andreas; Hajishengallis, George; Dimmeler, Stefanie; Chavakis, Triantafyllos; Chavakis, Emmanouil

    2017-01-01

    We have recently identified endothelial cell-secreted developmental endothelial locus-1 (Del-1) as an endogenous inhibitor of β2-integrin–dependent leukocyte infiltration. Del-1 was previously also implicated in angiogenesis. Here, we addressed the role of endogenously produced Del-1 in ischemia-related angiogenesis. Intriguingly, Del-1–deficient mice displayed increased neovascularization in two independent ischemic models (retinopathy of prematurity and hind-limb ischemia), as compared to Del-1–proficient mice. On the contrary, angiogenic sprouting in vitro or ex vivo (aortic ring assay) and physiological developmental retina angiogenesis were not affected by Del-1 deficiency. Mechanistically, the enhanced ischemic neovascularization in Del-1-deficiency was linked to higher infiltration of the ischemic tissue by CD45+ hematopoietic and immune cells. Moreover, Del-1-deficiency promoted β2-integrin–dependent adhesion of hematopoietic cells to endothelial cells in vitro, and the homing of hematopoietic progenitor cells and of immune cell populations to ischemic muscles in vivo. Consistently, the increased hind limb ischemia-related angiogenesis in Del-1 deficiency was completely reversed in mice lacking both Del-1 and the β2-integrin LFA-1. Additionally, enhanced retinopathy-associated neovascularization in Del-deficient mice was reversed by LFA-1 blockade. Our data reveal a hitherto unrecognized function of endogenous Del-1 as a local inhibitor of ischemia-induced angiogenesis by restraining LFA-1–dependent homing of pro-angiogenic hematopoietic cells to ischemic tissues. Our findings are relevant for the optimization of therapeutic approaches in the context of ischemic diseases. PMID:28447099

  1. Recall deficits in stroke patients with thalamic lesions covary with damage to the parvocellular mediodorsal nucleus of the thalamus.

    Science.gov (United States)

    Pergola, Giulio; Güntürkün, Onur; Koch, Benno; Schwarz, Michael; Daum, Irene; Suchan, Boris

    2012-08-01

    The functional role of the mediodorsal thalamic nucleus (MD) and its cortical network in memory processes is discussed controversially. While Aggleton and Brown (1999) suggested a role for recognition and not recall, Van der Werf et al. (2003) suggested that this nucleus is functionally related to executive function and strategic retrieval, based on its connections to the prefrontal cortices (PFC). The present study used a lesion approach including patients with focal thalamic lesions to examine the functions of the MD, the intralaminar nuclei and the midline nuclei in memory processing. A newly designed pair association task was used, which allowed the assessment of recognition and cued recall performance. Volume loss in thalamic nuclei was estimated as a predictor for alterations in memory performance. Patients performed poorer than healthy controls on recognition accuracy and cued recall. Furthermore, patients responded slower than controls specifically on recognition trials followed by successful cued recall of the paired associate. Reduced recall of picture pairs and increased response times during recognition followed by cued recall covaried with the volume loss in the parvocellular MD. This pattern suggests a role of this thalamic region in recall and thus recollection, which does not fit the framework proposed by Aggleton and Brown (1999). The functional specialization of the parvocellular MD accords with its connectivity to the dorsolateral PFC, highlighting the role of this thalamocortical network in explicit memory (Van der Werf et al., 2003). Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Functional characterization and expression of thalamic GABA(B) receptors in a rodent model of Parkinson's disease

    NARCIS (Netherlands)

    de Groote, C; Wullner, U; Loschmann, PA; Luiten, PGM; Klockgether, T

    1999-01-01

    Increased GABAergic neurotransmission of the basal ganglia output nuclei projecting to the motor thalamus is thought to contribute to the pathophysiology of Parkinson's disease. We investigated the functional role of thalamic GABA(B) receptors in a rodent model of Parkinson's disease. First, we

  3. Thalamic glucose metabolism in temporal lobe epilepsy measured with 18F-FDG positron emission tomography (PET)

    NARCIS (Netherlands)

    Khan, N; Leenders, KL; Hajek, M; Maguire, P; Missimer, J; Wieser, HG

    1997-01-01

    Thalamic glucose metabolism has been studied in 24 patients suffering from temporal lobe epilepsy (TLE) using interictal F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET). A total of 17 patients had a unilateral TL seizure onset, 11 of these patients had a mesial temporal lobe

  4. MM2-thalamic Creutzfeldt-Jakob disease: neuropathological, biochemical and transmission studies identify a distinctive prion strain.

    Science.gov (United States)

    Moda, Fabio; Suardi, Silvia; Di Fede, Giuseppe; Indaco, Antonio; Limido, Lucia; Vimercati, Chiara; Ruggerone, Margherita; Campagnani, Ilaria; Langeveld, Jan; Terruzzi, Alessandro; Brambilla, Antonio; Zerbi, Pietro; Fociani, Paolo; Bishop, Matthew T; Will, Robert G; Manson, Jean C; Giaccone, Giorgio; Tagliavini, Fabrizio

    2012-09-01

    In Creutzfeldt-Jakob disease (CJD), molecular typing based on the size of the protease resistant core of the disease-associated prion protein (PrP(Sc) ) and the M/V polymorphism at codon 129 of the PRNP gene correlates with the clinico-pathologic subtypes. Approximately 95% of the sporadic 129MM CJD patients are characterized by cerebral deposition of type 1 PrP(Sc) and correspond to the classic clinical CJD phenotype. The rare 129MM CJD patients with type 2 PrP(Sc) are further subdivided in a cortical and a thalamic form also indicated as sporadic fatal insomnia. We observed two young patients with MM2-thalamic CJD. Main neuropathological features were diffuse, synaptic PrP immunoreactivity in the cerebral cortex and severe neuronal loss and gliosis in the thalamus and olivary nucleus. Western blot analysis showed the presence of type 2A PrP(Sc) . Challenge of transgenic mice expressing 129MM human PrP showed that MM2-thalamic sporadic CJD (sCJD) was able to transmit the disease, at variance with MM2-cortical sCJD. The affected mice showed deposition of type 2A PrP(Sc) , a scenario that is unprecedented in this mouse line. These data indicate that MM2-thalamic sCJD is caused by a prion strain distinct from the other sCJD subtypes including the MM2-cortical form. © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology.

  5. Mesenteric ischemia: Pathogenesis and challenging diagnostic and therapeutic modalities.

    Science.gov (United States)

    Mastoraki, Aikaterini; Mastoraki, Sotiria; Tziava, Evgenia; Touloumi, Stavroula; Krinos, Nikolaos; Danias, Nikolaos; Lazaris, Andreas; Arkadopoulos, Nikolaos

    2016-02-15

    Mesenteric ischemia (MI) is an uncommon medical condition with high mortality rates. ΜΙ includes inadequate blood supply, inflammatory injury and eventually necrosis of the bowel wall. The disease can be divided into acute and chronic MI (CMI), with the first being subdivided into four categories. Therefore, acute MI (AMI) can occur as a result of arterial embolism, arterial thrombosis, mesenteric venous thrombosis and non-occlusive causes. Bowel damage is in proportion to the mesenteric blood flow decrease and may vary from minimum lesions, due to reversible ischemia, to transmural injury, with subsequent necrosis and perforation. CMI is associated to diffuse atherosclerotic disease in more than 95% of cases, with all major mesenteric arteries presenting stenosis or occlusion. Because of a lack of specific signs or due to its sometime quiet presentation, this condition is frequently diagnosed only at an advanced stage. Computed tomography (CT) imaging and CT angiography contribute to differential diagnosis and management of AMI. Angiography is also the criterion standard for CMI, with mesenteric duplex ultrasonography and magnetic resonance angiography also being of great importance. Therapeutic approach of MI includes both medical and surgical treatment. Surgical procedures include restoration of the blood flow with arteriotomy, endarterectomy or anterograde bypass, while resection of necrotic bowel is always implemented. The aim of this review was to evaluate the results of surgical treatment for MI and to present the recent literature in order to provide an update on the current concepts of surgical management of the disease. Mesh words selected include MI, diagnostic approach and therapeutic management.

  6. Medial thalamic 18-FDG uptake following inescapable shock correlates with subsequent learned helpless behavior

    International Nuclear Information System (INIS)

    Mirrione, M.M.; Schulz, D.; Dewey, S.L.; Henn, F.A.

    2009-01-01

    The learned helplessness paradigm has been repeatedly shown to correlate with neurobiological aspects of depression in humans. In this model, rodents are exposed inescapable foot-shock in order to reveal susceptibility to escape deficit, defined as 'learned helplessness' (LH). Few methods are available to probe the neurobiological aspects underlying the differences in susceptibility in the living animal, thus far being limited to studies examining regional neurochemical changes with microdialysis. With the widespread implementation of small animal neuroimaging methods, including positron emission tomography (PET), it is now possible to explore the living brain on a systems level to define regional changes that may correlate with vulnerability to stress. In this study, 12 wild type Sprague-Dawley rats were exposed to 40 minutes of inescapable foot-shock followed by metabolic imaging using 2-deoxy-2[ 18 F]fluoro-D-glucose (18-FDG) 1 hour later. The escape test was performed on these rats 48 hours later (to accommodate radiotracer decay), where they were given the opportunity to press a lever to shut off the shock. A region of interest (ROI) analysis was used to investigate potential correlations (Pearson Regression Coefficients) between regional 18-FDG uptake following inescapable shock and subsequent learned helpless behavior (time to finish the test; number of successful lever presses within 20 seconds of shock onset). ROI analysis revealed a significant positive correlation between time to finish and 18-FDG uptake, and a negative correlation between lever presses and uptake, in the medial thalamic area (p=0.033, p=0.036). This ROI included the paraventricular thalamus, mediodorsal thalamus, and the habenula. In an effort to account for possible spillover artifact, the posterior thalamic area (including ventral medial and lateral portions) was also evaluated but did not reveal significant correlations (p=0.870, p=0.897). No other significant correlations were found

  7. Renal ischemia reperfusion causes brain hippocampus oxidative ...

    African Journals Online (AJOL)

    Background: The acute kidney injury (AKI) may do damage to remote organs. Objective of the study is to investigate effect of seaweed extract (SE) on brain oxidative damage in kidney ischemia/reperfusion rats. Material and Methods: Animals were randomly divided into five groups. SE pre-fed to rats. Results: Kidney I/R ...

  8. The findings of Tc-99m ECD brain perfusion SPECT in the patients with left anterior thalamic infarction

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y. A.; Kim, S. H.; Sohn, H. S.; Jeong, S. G. [The Catholic University of Korea, Seoul (Korea, Republic of)

    2005-07-01

    The thalamus has multiple connections with areas of the cerebral cortex involved in arousal and cognition. Thalamic damage has been reported to be associated with variable neuropsychological dysfunctions and dementia. This study evaluates the changes of regional cerebral blood flow (rCBF) by using SPM analysis of brain perfusion SPECT and examining the neuropsychological abnormalities of 4 patients with anterior thalamic infarctions. Four patients with left anterior thalamic infarctions and eleven normal controls were evaluated. K-MMSE and the Seoul Neuropsychological Screening Battery were performed within 2 days after stroke. The normalized SPECT data of 4 patients were compared to those of 11 controls for the detection of areas with decreased rCBF by SPM analysis. All 4 patients showed anterograde amnesia in their verbal memory, which was not improved by recognition. Dysexecutive features were occasionally present, such as decreased word fluency and impaired Stroop test results. SPM analysis revealed decreased rCBF in the left supra marginal gyrus, the superior temporal gyrus, the middle and inferior frontal gyrus, the medial dorsal and anterior nucleus of the left thalamus. The changes of rCBF in patients with left anterior thalamic infarctions may be due to the remote suppression on metabolism by the interruption of the cortico-subcortical circuit, which connects the anterior thalamic nucleus and various cortical areas. The executive dysfunction and dysnomia may be caused by the left dorsolateral frontal dysfunction of the thalamo-cortical circuit. Anterograde amnesia with storage deficit may be caused by the disruption of mamillothalamic tract.

  9. The findings of Tc-99m ECD brain perfusion SPECT in the patients with left anterior thalamic infarction

    International Nuclear Information System (INIS)

    Jeong, Y. A.; Kim, S. H.; Sohn, H. S.; Jeong, S. G.

    2005-01-01

    The thalamus has multiple connections with areas of the cerebral cortex involved in arousal and cognition. Thalamic damage has been reported to be associated with variable neuropsychological dysfunctions and dementia. This study evaluates the changes of regional cerebral blood flow (rCBF) by using SPM analysis of brain perfusion SPECT and examining the neuropsychological abnormalities of 4 patients with anterior thalamic infarctions. Four patients with left anterior thalamic infarctions and eleven normal controls were evaluated. K-MMSE and the Seoul Neuropsychological Screening Battery were performed within 2 days after stroke. The normalized SPECT data of 4 patients were compared to those of 11 controls for the detection of areas with decreased rCBF by SPM analysis. All 4 patients showed anterograde amnesia in their verbal memory, which was not improved by recognition. Dysexecutive features were occasionally present, such as decreased word fluency and impaired Stroop test results. SPM analysis revealed decreased rCBF in the left supra marginal gyrus, the superior temporal gyrus, the middle and inferior frontal gyrus, the medial dorsal and anterior nucleus of the left thalamus. The changes of rCBF in patients with left anterior thalamic infarctions may be due to the remote suppression on metabolism by the interruption of the cortico-subcortical circuit, which connects the anterior thalamic nucleus and various cortical areas. The executive dysfunction and dysnomia may be caused by the left dorsolateral frontal dysfunction of the thalamo-cortical circuit. Anterograde amnesia with storage deficit may be caused by the disruption of mamillothalamic tract

  10. Altered cortico-striatal-thalamic connectivity in relation to spatial working memory capacity in children with ADHD

    Directory of Open Access Journals (Sweden)

    Kathryn L. Mills

    2012-01-01

    Full Text Available Introduction: Attention deficit hyperactivity disorder (ADHD captures a heterogeneous group of children, who are characterized by a range of cognitive and behavioral symptoms. Previous resting state functional connectivity (rs-fcMRI studies have sought to understand the neural correlates of ADHD by comparing connectivity measurements between those with and without the disorder, focusing primarily on cortical-striatal circuits mediated by the thalamus. To integrate the multiple phenotypic features associated with ADHD and help resolve its heterogeneity, it is helpful to determine how specific circuits relate to unique cognitive domains of the ADHD syndrome. Spatial working memory has been proposed as a key mechanism in the pathophysiology of ADHD.Methods: We correlated the rs-fcMRI of five thalamic regions of interest with spatial span working memory scores in a sample of 67 children aged 7-11 years (ADHD and typically developing children; TDC. In an independent dataset, we then examined group differences in thalamo-striatal functional connectivity between 70 ADHD and 89 TDC (7-11 years from the ADHD-200 dataset. Thalamic regions of interest were created based on previous methods that utilize known thalamo-cortical loops and rs-fcMRI to identify functional boundaries in the thalamus.Results/Conclusions: Using these thalamic regions, we found atypical rs-fcMRI between specific thalamic groupings with the basal ganglia. To identify the thalamic connections that relate to spatial working memory in ADHD, only connections identified in both the correlational and comparative analyses were considered. Multiple connections between the thalamus and basal ganglia, particularly between medial and anterior dorsal thalamus and the putamen, were related to spatial working memory and also altered in ADHD. These thalamo-striatal disruptions may be one of multiple atypical neural and cognitive mechanisms that relate to the ADHD clinical phenotype.

  11. Acute mesenteric ischemia: a vascular emergency.

    Science.gov (United States)

    Klar, Ernst; Rahmanian, Parwis B; Bücker, Arno; Hauenstein, Karlheinz; Jauch, Karl-Walter; Luther, Bernd

    2012-04-01

    Acute mesenteric ischemia is still fatal in 50% to 70% of cases. This consensus paper was written with the participation of physicians from all of the involved specialties for the purpose of improving outcomes. Mesenteric ischemia must be recognized as a vascular emergency requiring rapid and efficient clinical evaluation and treatment. We reviewed pertinent literature that was retrieved by a PubMed search on the terms "mesenteric ischemia" AND "arterial" OR "venous" OR "clinical presentation" OR "diagnosis" OR "therapy" OR "surgery" OR " interventional radiology." Our review also took account of the existing guidelines of the American College of Cardiology/American Heart Association. Intensive discussions among the participating physicians, representing all of the specialties involved in the management of mesenteric ischemia, led to the creation of this interdisciplinary paper. Biphasic contrast-enhanced computerized tomography is the diagnostic tool of choice for the detection of arterial or venous occlusion. If non-occlusive mesenteric ischemia is suspected, angiography should be performed, with the option of intraarterial pharmacotherapy to induce local vasodilation. Endovascular techniques have become increasingly important in the treatment of arterial occlusion. Embolic central mesenteric artery occlusion requires surgical treatment; surgery is also needed in case of peritonitis. Portal-vein thrombosis can be treated by local thrombolysis through a transhepatically placed catheter. This should be done within 3 to 4 weeks of the event to prevent later complications of portal hypertension. Rapid diagnosis (within 4 to 6 hours of symptom onset) and interdisciplinary cooperation in the provision of treatment are required if the poor outcome of this condition is to be improved.

  12. Bilateral symmetrical basal ganglia and thalamic lesions in children: an update (2015)

    International Nuclear Information System (INIS)

    Zuccoli, Giulio; Yannes, Michael Paul; Nardone, Raffaele; Bailey, Ariel; Goldstein, Amy

    2015-01-01

    In children, many inherited or acquired neurological disorders may cause bilateral symmetrical signal intensity alterations in the basal ganglia and thalami. A literature review was aimed at assisting neuroradiologists, neurologists, infectious diseases specialists, and pediatricians to provide further understanding into the clinical and neuroimaging features in pediatric patients presenting with bilateral symmetrical basal ganglia and thalamic lesions on magnetic resonance imaging (MRI). We discuss hypoxic-ischemic, toxic, infectious, immune-mediated, mitochondrial, metabolic, and neurodegenerative disorders affecting the basal ganglia and thalami. Recognition and correct evaluation of basal ganglia abnormalities, together with a proper neurological examination and laboratory findings, may enable the identification of each of these clinical entities and lead to earlier diagnosis. (orig.)

  13. [Deficit of verbal recall caused by left dorso-lateral thalamic infarction].

    Science.gov (United States)

    Rousseaux, M; Cabaret, M; Benaim, C; Steinling, M

    1995-01-01

    A case of amnesia with preferential disorder of verbal recall, associated to a limited infarct of the left superior, external and anterior thalamus, is reported. This lesion involved the anterior and middle dorso-lateral nuclei and the centrolateral nucleus, sparing most of the structures classically incriminated in diencephalic amnesia. At the initial stage, the patient presented discrete language impairment and severe deficit of semantic processing, which later recovered. At the late stage, the anterograde and retrograde amnesia principally concerned the recall of verbal information used in daily life, verbal learning using short-term and long-term recall, questionnaires evaluating retrograde memory and requiring the evocation of proper names. Verbal priming was also affected. Verbal recognition was preserved. Evocation of the most recent events of the personal life was also impaired. Confrontation of this case with others previously reported suggests that various thalamic amnesias may be described, associated to different cognitive deficits, in relation with the preferential situation of lesions.

  14. Bilateral symmetrical basal ganglia and thalamic lesions in children: an update (2015)

    Energy Technology Data Exchange (ETDEWEB)

    Zuccoli, Giulio [Children' s Hospital of Pittsburgh of UPMC, Section of Neuroradiology, Pittsburgh, PA (United States); Yannes, Michael Paul [University of Pittsburgh School of Medicine, Department of Radiology, Pittsburgh, PA (United States); Nardone, Raffaele [Paracelsus Medical University, Department of Neurology, Christian Doppler Klinik, Salzburg (Austria); Bailey, Ariel [West Virginia University, Department of Radiology, Morgantown, WV (United States); Goldstein, Amy [Children' s Hospital of Pittsburgh of UPMC, Department of Neurology, Section of Metabolic Disorders and Neurogenetics, Pittsburgh, PA (United States)

    2015-10-15

    In children, many inherited or acquired neurological disorders may cause bilateral symmetrical signal intensity alterations in the basal ganglia and thalami. A literature review was aimed at assisting neuroradiologists, neurologists, infectious diseases specialists, and pediatricians to provide further understanding into the clinical and neuroimaging features in pediatric patients presenting with bilateral symmetrical basal ganglia and thalamic lesions on magnetic resonance imaging (MRI). We discuss hypoxic-ischemic, toxic, infectious, immune-mediated, mitochondrial, metabolic, and neurodegenerative disorders affecting the basal ganglia and thalami. Recognition and correct evaluation of basal ganglia abnormalities, together with a proper neurological examination and laboratory findings, may enable the identification of each of these clinical entities and lead to earlier diagnosis. (orig.)

  15. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: Application of a biomarker development strategy

    Directory of Open Access Journals (Sweden)

    Daniel S. Barron

    2015-01-01

    No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons. Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.

  16. Fluctuating drowsiness following cardiac catheterisation: artery of Percheron ischaemic stroke causing bilateral thalamic infarcts.

    Science.gov (United States)

    Hammersley, Daniel; Arora, Ankur; Dissanayake, Madhava; Sengupta, Nabarun

    2017-01-02

    An 81-year-old man underwent cardiac catheterisation to investigate breathlessness and left ventricular impairment of unknown cause. He had unobstructed coronary arteries. Immediately following the procedure, he became suddenly unresponsive with vertical gaze palsy, anisocoria and bilateral upgoing plantar responses. He made a rapid recovery to his premorbid state 25 min later with no residual focal neurological signs. He then had multiple unresponsive episodes, interspaced with complete resolution of symptoms and neurological signs. MRI of the brain identified bilateral medial thalamic infarcts and midbrain infarcts, consistent with an artery of Percheron territory infarction. By the time the diagnosis was reached, the thrombolysis window had elapsed. The unresponsive episodes diminished with time and the patient was discharged to inpatient rehabilitation. At 6-month review after the episode, the patient has a degree of progressive cognitive impairment. 2017 BMJ Publishing Group Ltd.

  17. Thalamic metabolic abnormalities in patients with Huntington's disease measured by magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Casseb, R.F.; Castellano, G., E-mail: gabriela@ifi.unicamp.br [Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil); Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Fisica Gleb Wataghin. Dept. de Raios Cosmicos e Cronologia; D' Abreu, A.; Cendes, F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Dept. de Neurologia. Lab. de Neuroimagem; Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil); Ruocco, H.H. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Ciencias Medicas. Dept. de Neurologia. Lab. de Neuroimagem; Lopes-Cendes, I., E-mail: seixas.fk@gmail.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Ciencias Medicas. Dept. de Genetica Medica; Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil)

    2013-08-15

    Huntington's disease (HD) is a neurologic disorder that is not completely understood; its fundamental physiological mechanisms and chemical effects remain somewhat unclear. Among these uncertainties, we can highlight information about the concentrations of brain metabolites, which have been widely discussed. Concentration differences in affected, compared to healthy, individuals could lead to the development of useful tools for evaluating the progression of disease, or to the advance of investigations of different/alternative treatments. The aim of this study was to compare the thalamic concentration of metabolites in HD patients and healthy individuals using magnetic resonance spectroscopy. We used a 2.0-Tesla magnetic field, repetition time of 1500 ms, and echo time of 135 ms. Spectra from 40 adult HD patients and 26 control subjects were compared. Quantitative analysis was performed using the LCModel method. There were statistically significant differences between HD patients and controls in the concentrations of N-acetylaspartate+N-acetylaspartylglutamate (NAA+NAAG; t-test, P,0.001), and glycerophosphocholine+phosphocholine (GPC+PCh; t-test, P=0.001) relative to creatine+phosphocreatine (Cr+PCr). The NAA+NAAG/Cr+PCr ratio was decreased by 9% and GPC+PCh/Cr+PCr increased by 17% in patients compared with controls. There were no correlations between the concentration ratios and clinical features. Although these results could be caused by T1 and T2 changes, rather than variations in metabolite concentrations given the short repetition time and long echo time values used, our findings point to thalamic dysfunction, corroborating prior evidence. (author)

  18. CT classification of small thalamic hemorrhages. Topographic localization and clinical manifestation

    Energy Technology Data Exchange (ETDEWEB)

    Kawahara, Nobutaka; Kaneko, Mitsuo; Tanaka, Keisei; Muraki, Masaaki; Sato, Kengo (Hamamatsu Medical Center Hospital, Shizuoka (Japan))

    1984-06-01

    The thalamus is located deep in the cerebral hemispheres, and most of its nuclei have reciprocal fiber connections with specific areas over the cerebral cortex. Localized lesions in the thalamus, therefore, can cause specific neurological deficits, depending on their locations. From this point of view, we reviewed 110 cases, admitted over the past 7 years, with thalamic hemorrhages 37 (34%) of which were small hematomas less than 2 cm in diameter. These small hematomas could be divided into 4 types depending on their locations as follows: antero-lateral type, postero-lateral type, medial type, and dorsal type. Each type had the peculiar clinical features described below: 1) Postero-lateral Type (PL type, 28 cases, 76%): The original symptom was a sudden onset of moderate to severe sensori-motor deficits in most cases. The patients were mostly alert or only slightly confused. 2) Antero-lateral Type (AL type, 4 cases, 11%): The patients of this type first presented with sensori-motor disturbance and prefrontal signs. Both were generally mild and often disappeared early. 3) Medial Type (M type, 3 cases, 8%): The main symptom at onset was either a disturbance of consciousness or dementia. 4) Dorsal Type (D type, 2 cases, 5%): One patient with a right thalamic hematoma of this type showed geographical agnosia and visuo-constructive apraxia. The other patient, with a left-sided hematoma, exhibited transient clumsiness of the right hand and mild dysphasia. In our experience, the above classification of small hematomas clearly delineated the clinical symptoms and neurological signs of the different types; therefore, the symptoms and signs in larger hematoma could be explained by a combination of those of each type.

  19. Thalamic connections of the core auditory cortex and rostral supratemporal plane in the macaque monkey.

    Science.gov (United States)

    Scott, Brian H; Saleem, Kadharbatcha S; Kikuchi, Yukiko; Fukushima, Makoto; Mishkin, Mortimer; Saunders, Richard C

    2017-11-01

    In the primate auditory cortex, information flows serially in the mediolateral dimension from core, to belt, to parabelt. In the caudorostral dimension, stepwise serial projections convey information through the primary, rostral, and rostrotemporal (AI, R, and RT) core areas on the supratemporal plane, continuing to the rostrotemporal polar area (RTp) and adjacent auditory-related areas of the rostral superior temporal gyrus (STGr) and temporal pole. In addition to this cascade of corticocortical connections, the auditory cortex receives parallel thalamocortical projections from the medial geniculate nucleus (MGN). Previous studies have examined the projections from MGN to auditory cortex, but most have focused on the caudal core areas AI and R. In this study, we investigated the full extent of connections between MGN and AI, R, RT, RTp, and STGr using retrograde and anterograde anatomical tracers. Both AI and R received nearly 90% of their thalamic inputs from the ventral subdivision of the MGN (MGv; the primary/lemniscal auditory pathway). By contrast, RT received only ∼45% from MGv, and an equal share from the dorsal subdivision (MGd). Area RTp received ∼25% of its inputs from MGv, but received additional inputs from multisensory areas outside the MGN (30% in RTp vs. 1-5% in core areas). The MGN input to RTp distinguished this rostral extension of auditory cortex from the adjacent auditory-related cortex of the STGr, which received 80% of its thalamic input from multisensory nuclei (primarily medial pulvinar). Anterograde tracers identified complementary descending connections by which highly processed auditory information may modulate thalamocortical inputs. © 2017 Wiley Periodicals, Inc.

  20. Astrocytes potentiate GABAergic transmission in the thalamic reticular nucleus via endozepine signaling.

    Science.gov (United States)

    Christian, Catherine A; Huguenard, John R

    2013-12-10

    Emerging evidence indicates that diazepam-binding inhibitor (DBI) mediates an endogenous benzodiazepine-mimicking (endozepine) effect on synaptic inhibition in the thalamic reticular nucleus (nRT). Here we demonstrate that DBI peptide colocalizes with both astrocytic and neuronal markers in mouse nRT, and investigate the role of astrocytic function in endozepine modulation in this nucleus by testing the effects of the gliotoxin fluorocitrate (FC) on synaptic inhibition and endozepine signaling in the nRT using patch-clamp recordings. FC treatment reduced the effective inhibitory charge of GABAA receptor (GABAAR)-mediated spontaneous inhibitory postsynaptic currents in WT mice, indicating that astrocytes enhance GABAAR responses in the nRT. This effect was abolished by both a point mutation that inhibits classical benzodiazepine binding to GABAARs containing the α3 subunit (predominant in the nRT) and a chromosomal deletion that removes the Dbi gene. Thus, astrocytes are required for positive allosteric modulation via the α3 subunit benzodiazepine-binding site by DBI peptide family endozepines. Outside-out sniffer patches pulled from neurons in the adjacent ventrobasal nucleus, which does not contain endozepines, show a potentiated response to laser photostimulation of caged GABA when placed in the nRT. FC treatment blocked the nRT-dependent potentiation of this response, as did the benzodiazepine site antagonist flumazenil. When sniffer patches were placed in the ventrobasal nucleus, however, subsequent treatment with FC led to potentiation of the uncaged GABA response, suggesting nucleus-specific roles for thalamic astrocytes in regulating inhibition. Taken together, these results suggest that astrocytes are required for endozepine actions in the nRT, and as such can be positive modulators of synaptic inhibition.

  1. Thalamic metabolic abnormalities in patients with Huntington's disease measured by magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Casseb, R.F.; Castellano, G.; Ruocco, H.H.

    2013-01-01

    Huntington's disease (HD) is a neurologic disorder that is not completely understood; its fundamental physiological mechanisms and chemical effects remain somewhat unclear. Among these uncertainties, we can highlight information about the concentrations of brain metabolites, which have been widely discussed. Concentration differences in affected, compared to healthy, individuals could lead to the development of useful tools for evaluating the progression of disease, or to the advance of investigations of different/alternative treatments. The aim of this study was to compare the thalamic concentration of metabolites in HD patients and healthy individuals using magnetic resonance spectroscopy. We used a 2.0-Tesla magnetic field, repetition time of 1500 ms, and echo time of 135 ms. Spectra from 40 adult HD patients and 26 control subjects were compared. Quantitative analysis was performed using the LCModel method. There were statistically significant differences between HD patients and controls in the concentrations of N-acetylaspartate+N-acetylaspartylglutamate (NAA+NAAG; t-test, P,0.001), and glycerophosphocholine+phosphocholine (GPC+PCh; t-test, P=0.001) relative to creatine+phosphocreatine (Cr+PCr). The NAA+NAAG/Cr+PCr ratio was decreased by 9% and GPC+PCh/Cr+PCr increased by 17% in patients compared with controls. There were no correlations between the concentration ratios and clinical features. Although these results could be caused by T1 and T2 changes, rather than variations in metabolite concentrations given the short repetition time and long echo time values used, our findings point to thalamic dysfunction, corroborating prior evidence. (author)

  2. Strategic lesions in the anterior thalamic radiation and apathy in early Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Mario Torso

    Full Text Available Behavioural disorders and psychological symptoms of Dementia (BPSD are commonly observed in Alzheimer's disease (AD, and strongly contribute to increasing patients' disability. Using voxel-lesion-symptom mapping (VLSM, we investigated the impact of white matter lesions (WMLs on the severity of BPSD in patients with amnestic mild cognitive impairment (a-MCI.Thirty-one a-MCI patients (with a conversion rate to AD of 32% at 2 year follow-up and 26 healthy controls underwent magnetic resonance imaging (MRI examination at 3T, including T2-weighted and fluid-attenuated-inversion-recovery images, and T1-weighted volumes. In the patient group, BPSD was assessed using the Neuropsychiatric Inventory-12. After quantitative definition of WMLs, their distribution was investigated, without an a priori anatomical hypothesis, against patients' behavioural symptoms. Unbiased regional grey matter volumetrics was also used to assess the contribution of grey matter atrophy to BPSD.Apathy, irritability, depression/dysphoria, anxiety and agitation were shown to be the most common symptoms in the patient sample. Despite a more widespread anatomical distribution, a-MCI patients did not differ from controls in WML volumes. VLSM revealed a strict association between the presence of lesions in the anterior thalamic radiations (ATRs and the severity of apathy. Regional grey matter atrophy did not account for any BPSD.This study indicates that damage to the ATRs is strategic for the occurrence of apathy in patients with a-MCI. Disconnection between the prefrontal cortex and the mediodorsal and anterior thalamic nuclei might represent the pathophysiological substrate for apathy, which is one of the most common psychopathological symptoms observed in dementia.

  3. Positron emission tomography imaging of angiogenesis in a murine hindlimb ischemia model with 64Cu-labeled TRC105.

    Science.gov (United States)

    Orbay, Hakan; Zhang, Yin; Hong, Hao; Hacker, Timothy A; Valdovinos, Hector F; Zagzebski, James A; Theuer, Charles P; Barnhart, Todd E; Cai, Weibo

    2013-07-01

    The goal of this study was to assess ischemia-induced angiogenesis with (64)Cu-NOTA-TRC105 positron emission tomography (PET) in a murine hindlimb ischemia model of peripheral artery disease (PAD). CD105 binding affinity/specificity of NOTA-conjugated TRC105 (an anti-CD105 antibody) was evaluated by flow cytometry, which exhibited no difference from unconjugated TRC105. BALB/c mice were anesthetized, and the right femoral artery was ligated to induce hindlimb ischemia, with the left hindlimb serving as an internal control. Laser Doppler imaging showed that perfusion in the ischemic hindlimb plummeted to ∼ 20% of the normal level after surgery and gradually recovered to near normal level on day 24. Ischemia-induced angiogenesis was noninvasively monitored and quantified with (64)Cu-NOTA-TRC105 PET on postoperative days 1, 3, 10, 17, and 24. (64)Cu-NOTA-TRC105 uptake in the ischemic hindlimb increased significantly from the control level of 1.6 ± 0.2 %ID/g to 14.1 ± 1.9 %ID/g at day 3 (n = 3) and gradually decreased with time (3.4 ± 1.9 %ID/g at day 24), which correlated well with biodistribution studies performed on days 3 and 24. Blocking studies confirmed the CD105 specificity of tracer uptake in the ischemic hindlimb. Increased CD105 expression on days 3 and 10 following ischemia was confirmed by histology and reverse transcription polymerase chain reaction (RT-PCR). This is the first report of PET imaging of CD105 expression during ischemia-induced angiogenesis. (64)Cu-NOTA-TRC105 PET may play multiple roles in future PAD-related research and improve PAD patient management by identifying the optimal timing of treatment and monitoring the efficacy of therapy.

  4. Green tea polyphenols alleviate early BBB damage during experimental focal cerebral ischemia through regulating tight junctions and PKCalpha signaling.

    Science.gov (United States)

    Liu, Xiaobai; Wang, Zhenhua; Wang, Ping; Yu, Bo; Liu, Yunhui; Xue, Yixue

    2013-07-21

    It has been supposed that green tea polyphenols (GTPs) have neuroprotective effects on brain damage after brain ischemia in animal experiments. Little is known regarding GTPs' protective effects against the blood-brain barrier (BBB) disruption after ischemic stroke. We investigated the effects of GTPs on the expression of claudin-5, occludin, and ZO-1, and the corresponding cellular mechanisms involved in the early stage of cerebral ischemia. Male Wistar rats were subjected to a middle cerebral artery occlusion (MCAO) for 0, 30, 60, and 120 min. GTPs (400 mg/kg/day) or vehicle was administered by intragastric gavage twice a day for 30 days prior to MCAO. At different time points, the expression of claudin-5, occludin, ZO-1, and PKCα signaling pathway in microvessel fragments of cerebral ischemic tissue were evaluated. GTPs reduced BBB permeability at 60 min and 120 min after ischemia as compared with the vehicle group. Transmission electron microscopy also revealed that GTPs could reverse the opening of tight junction (TJ) barrier at 60 min and 120 min after MACO. The decreased mRNA and protein expression levels of claudin-5, occludin, and ZO-1 in microvessel fragments of cerebral ischemic tissue were significantly prevented by treatment with GTPs at the same time points after ischemia in rats. Furthermore, GTPs could attenuate the increase in the expression levels of PKCα mRNA and protein caused by cerebral ischemia. These results demonstrate that GTPs may act as a potential neuroprotective agent against BBB damage at the early stage of focal cerebral ischemia through the regulation of TJ and PKCα signaling.

  5. Cycloheximide and actinomycin D delay death and affect bcl-2, bax, and Ice gene expression in astrocytes under in vitro ischemia.

    Science.gov (United States)

    Yu, Albert Cheung Hoi; Yung, Hon Wa; Hui, Michael Hung Kit; Lau, Lok Ting; Chen, Xiao Qian; Collins, Richard A

    2003-10-15

    An in vitro ischemia model was established and the effect of the metabolic inhibitors cycloheximide (CHX) and actinomycin D (ActD) on apoptosis in astrocytes under ischemia studied. CHX decreased by 75% the number of cells dying after 6 hr of ischemia compared with control cultures. TdT-mediated dUTP nick end labelling (TUNEL) staining of comparable cultures was reduced by 40%. ActD decreased cell death by 60% compared with controls. The number of TUNEL-positive cells was reduced by 38%. The nuclear shrinkage in TUNEL-positive astrocytes in control cultures did not occur in ActD-treated astrocytes, indicating that nuclear shrinkage and DNA fragmentation during apoptosis are two unrelated processes. Expression of bcl-2 (alpha and beta), bax, and Ice in astrocytes under similar ischemic conditions, as measured by quantitative reverse transcription-polymerase chain reaction, indicated that ischemia down-regulated bcl-2 (alpha and beta) and bax. Ice was initially down-regulated from 0 to 4 hr, before returning to control levels after 8 hr of ischemia. ActD decreased the expression of these genes. CHX reduced the expression of bcl-2 (alpha and beta) but increased bax and Ice expression. It is hypothesized that the balance of proapoptotic (Bad, Bax) and antiapoptotic (Bcl-2, Bcl-Xl) proteins determines apoptosis. The data suggest that the ratio of Bcl-2/Bad in astrocytes following ActD and CHX treatment does not decrease as much in untreated cells during ischemia. Our data indicate that it is the ratio of Bcl-2 family members that plays a critical role in determining ischemia-induced apoptosis. It is also important to note that ischemia-induced apoptosis involves the regulation of RNA and protein synthesis. Copyright 2003 Wiley-Liss, Inc.

  6. Mesenchymal stem cells increase antioxidant capacity in intestinal ischemia/reperfusion damage.

    Science.gov (United States)

    Inan, M; Bakar, E; Cerkezkayabekir, A; Sanal, F; Ulucam, E; Subaşı, C; Karaöz, E

    2017-07-01

    Mesenchymal stem cells (MSCs) may have beneficial effects in reversing intestinal damage resulting from circulatory disorders. The hypothesis of this study is that MSCs increase antioxidant capacity of small bowel tissue following intestinal ischemia reperfusion (I/R) damage. A total of 100 rats were used for the control group and three experimental groups, as follows: the sham control, local MSC, and systemic MSC groups. Each group consisted of 10 animals on days 1, 4, and 7 of the experiment. Ischemia was established by clamping the superior mesenteric artery (SMA) for 45min; following this, reperfusion was carried out for 1, 4, and 7days in all groups. In the local and systemic groups, MSCs were administered intravenously and locally just after the ischemia, and they were investigated after 1, 4, and 7days. The superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (Gpx) activities, as well as malondialdehyde (MDA) and total protein levels, were measured. Histopathological analysis was performed using light and electron microscopy. The indicators of proliferation from the effects of anti- and pro-inflammatory cytokines were evaluated using immunohistochemistry. MDA was increased (Pcytokines interleukin-1β (IL1β), transforming growth factor-β1 (TGFβ1), tumor necrosis factor-α (TNFα), IL6, MIP2, and MPO decreased (Pcytokines EP3 and IL1ra increased (poxygen radicals, suppression of pro-inflammatory cytokines, and increasing the expression of anti-inflammatory cytokines. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Myocardial fatty acid utilisation during exercise induced ischemia in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Virtanen, K.S.; Nikkinen, P.; Lindroth, L.; Kuikka, J.T.

    2002-01-01

    Aim: Reversible or irreversible myocardial damage due to ischemia correlates with altered membrane functions of the cells. To compare myocardial free fatty acid (FFA) metabolism and flow during exercise induced ischemia we studied ten patients with coronary artery disease but without previous myocardial infarction. Methods: A series of post-exercise single-photon emission computed tomography (SPECT) measurements was performed after injection of 123 I labelled heptadecanoic acid (HDA). Myocardial perfusion was estimated from the separately performed exercise-redistribution thallium study. Fatty acid metabolic rate, thallium uptake and washout were calculated for anterior, lateral, posterior and septal segments. Results: The more reduced post-exercise FFA metabolic rate (-63±18%, mean ±1 SD) compared to flow (-36±16%) was related to the severity of myocardial ischemia and wall motion abnormalities. Conclusion: In this small group of patients, the reduced post-exercise FFA metabolic rate tentatively suggests a parsimonious workload of the exercising myocardium by reducing oxygen consumption in patients with coronary artery disease. (orig.) [de

  8. Vascular access in critical limb ischemia.

    Science.gov (United States)

    Kang, Won Yu; Campia, Umberto; Ota, Hideaki; Didier, Romain J; Negi, Smita I; Kiramijyan, Sarkis; Koifman, Edward; Baker, Nevin C; Magalhaes, Marco A; Lipinski, Michael J; Escarcega, Ricardo O; Torguson, Rebecca; Waksman, Ron; Bernardo, Nelson L

    2016-01-01

    Currently, percutaneous endovascular intervention is considered a first line of therapy for treating patients with critical limb ischemia. As the result of remarkable development of techniques and technologies, percutaneous endovascular intervention has led to rates of limb salvage comparable to those achieved with bypass surgery, with fewer complications, even in the presence of lower rates of long-term patency. Currently, interventionalists have a multiplicity of access routes including smaller arteries, with both antegrade and retrograde approaches. Therefore, the choice of the optimal access site has become an integral part of the success of the percutaneous intervention. By understanding the technical aspects, as well as the advantages and limitations of each approach, the interventionalists can improve clinical outcomes in patients with severe peripheral arterial disease. This article reviews the access routes in critical limb ischemia, their advantages and disadvantages, and the clinical outcomes of each. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Endovascular Management of Acute Limb Ischemia.

    LENUS (Irish Health Repository)

    Hynes, Brian G

    2011-09-14

    Despite major advances in pharmacologic and endovascular therapies, acute limb ischemia (ALI) continues to result in significant morbidity and mortality. The incidence of ALI may be as high as 13-17 cases per 100,000 people per year, with mortality rates approaching 18% in some series. This review will address the contemporary endovascular management of ALI encompassing pharmacologic and percutaneous interventional treatment strategies.

  10. The study of the tolerance to skeletal muscle ischemia

    International Nuclear Information System (INIS)

    Tsubo, Masahiko; Takai, Hiroaki; Ikata, Takaaki; Sogabe, Takayuki; Miura, Iwao.

    1988-01-01

    A model of amputated and replanted legs were used for the study on the energy metabolism during long-period skeletal muscle ischemia. The energy metabolic changes and intracellular pH were measured continuously and non-invasively by 31 P-MRS technique. Immediately following ischemia, phosphocreatine declined and inorganic phosphate rose. However, ATP was maintained for 2 hours. During ischemia, phosphocreatine was not detected after about 3.5 hours and ATP was no longer detectable after about 5 hours. On the other hand, intracellular pH began declining linearly after 30 minutes. All cases of 4-hour ischemia and 57 % of 5-hour ischemia recovered. And all cases of 6-hour ischemia did not recover. (author)

  11. Purine Metabolism in Acute Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Ye. V. Oreshnikov

    2008-01-01

    Full Text Available Objective: to study the specific features of purine metabolism in clinically significant acute cerebral ischemia. Subjects and materials. Three hundred and fifty patients with the acutest cerebral ischemic stroke were examined. The parameters of gas and electrolyte composition, acid-base balance, the levels of malonic dialdehyde, adenine, guanine, hypox-anthine, xanthine, and uric acid, and the activity of xanthine oxidase were determined in arterial and venous bloods and spinal fluid. Results. In ischemic stroke, hyperuricemia reflects the severity of cerebral metabolic disturbances, hemodynamic instability, hypercoagulation susceptiility, and the extent of neurological deficit. In ischemic stroke, hyperuri-corachia is accompanied by the higher spinal fluid levels of adenine, guanine, hypoxanthine, and xanthine and it is an indirect indicator of respiratory disorders of central genesis, systemic acidosis, hypercoagulation susceptibility, free radical oxidation activation, the intensity of a stressor response to cerebral ischemia, cerebral metabolic disturbances, the depth of reduced consciousness, and the severity of neurological deficit. Conclusion. The high venous blood activity of xanthine oxidase in ischemic stroke is associated with the better neurological parameters in all follow-up periods, the better early functional outcome, and lower mortality rates. Key words: hyperuricemia, stroke, xanthine oxidase, uric acid, cerebral ischemia.

  12. Post-Traumatic Late Onset Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Gencer Genc

    2014-03-01

    Full Text Available Artery-to-artery emboli or occlusion of craniocervical arteries mostly due to dissection are the most common causes of ischemia after trauma. A 29 year-old male had been admitted to another hospital with loss of consciousness lasting for about 45 minutes after a hard parachute landing without head trauma three days ago. As his neurological examination and brain CT were normal, he had been discharged after 24 hours of observation. Two days after his discharge, he was admitted to our department with epileptic seizure. His neurological examination revealed left hemianopia. After observing occipital subacute ischemia at right side in brain magnetic resonance imaging (MRI, we performed cerebral angiography and no dissection was observed. Excluding the rheumatologic, cardiologic and vascular events, our final diagnosis was late onset cerebral ischemia. Anti-edema and antiepileptic treatment was initiated. He was discharged with left hemianopia and mild cognitive deficit. We suggest that it will be wise to hospitalize patients for at least 72 hours who has a history of unconsciousness following trauma.

  13. Sex Differences in Mental Stress-Induced Myocardial Ischemia in Patients With Coronary Heart Disease.

    Science.gov (United States)

    Vaccarino, Viola; Wilmot, Kobina; Al Mheid, Ibhar; Ramadan, Ronnie; Pimple, Pratik; Shah, Amit J; Garcia, Ernest V; Nye, Jonathon; Ward, Laura; Hammadah, Muhammad; Kutner, Michael; Long, Qi; Bremner, J Douglas; Esteves, Fabio; Raggi, Paolo; Quyyumi, Arshed A

    2016-08-24

    Emerging data suggest that young women with coronary heart disease (CHD) are disproportionally vulnerable to the adverse cardiovascular effects of psychological stress. We hypothesized that younger, but not older, women with stable CHD are more likely than their male peers to develop mental stress-induced myocardial ischemia (MSIMI). We studied 686 patients (191 women) with stable coronary heart disease (CHD). Patients underwent (99m)Tc-sestamibi myocardial perfusion imaging at rest and with both mental (speech task) and conventional (exercise/pharmacological) stress testing. We compared quantitative (by automated software) and visual parameters of inducible ischemia between women and men and assessed age as an effect modifier. Women had a more-adverse psychosocial profile than men whereas there were few differences in medical history and CHD risk factors. Both quantitative and visual indicators of ischemia with mental stress were disproportionally larger in younger women. For each 10 years of decreasing age, the total reversibility severity score with mental stress was 9.6 incremental points higher (interaction, P<0.001) and the incidence of MSIMI was 82.6% higher (interaction, P=0.004) in women than in men. Incidence of MSIMI in women ≤50 years was almost 4-fold higher than in men of similar age and older patients. These results persisted when adjusting for sociodemographic and medical risk factors, psychosocial factors, and medications. There were no significant sex differences in inducible ischemia with conventional stress. Young women with stable CHD are susceptible to MSIMI, which could play a role in the prognosis of this group. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  14. Holmes’ Tremor with Shoulder Pain Treated by Deep Brain Stimulation of Unilateral Ventral Intermediate Thalamic Nucleus and Globus Pallidus Internus

    Directory of Open Access Journals (Sweden)

    Sabri Aydın

    2017-05-01

    Full Text Available A 21-year-old male was admitted with severe right arm and hand tremors after a thalamic hemorrhage caused by a traffic accident. He was also suffering from agonizing pain in his right shoulder that manifested after the tremor. Neurologic examination revealed a disabling, severe, and irregular kinetic and postural tremor in the right arm during target-directed movements. There was also an irregular ipsilateral rest tremor and dystonic movements in the distal part of the right arm. The amplitude was moderate at rest and extremely high during kinetic and intentional movements. The patient underwent left globus pallidum internus and ventral intermediate thalamic nucleus deep brain stimulation. The patient improved by more than 80% as rated by the Fahn-Tolosa-Marin Tremor Rating Scale and Visual Analog Scale six months after surgery.

  15. Noninvasive evaluation of myocardial ischemia in patients with heart problems

    Directory of Open Access Journals (Sweden)

    Mehdi Nikseresht

    2018-03-01

    Conclusion: It seems that the higher risk of myocardial ischemia in men aged 60-77 years, as compared to men aged 45-59 years, might be related to aging process and imbalance in the risk factors. Promoting physical activity can favorably affect the risk of myocardial ischemia in the middle-aged or elderly men. It is concluded that physical activity effectively decreased the risk of myocardial ischemia.

  16. Managing Reverse Logistics or Reversing Logistics Management?

    OpenAIRE

    Brito, Marisa

    2004-01-01

    textabstractIn the past, supply chains were busy fine-tuning the logistics from raw material to the end customer. Today an increasing flow of products is going back in the chain. Thus, companies have to manage reverse logistics as well.This thesis contributes to a better understanding of reverse logistics. The thesis brings insights on reverse logistics decision-making and it lays down theoretical principles for reverse logistics as a research field.In particular it puts together a framework ...

  17. Role of ultrasound-guided continuous brachial plexus block in the management of neonatal ischemia in upper limb

    Directory of Open Access Journals (Sweden)

    Vrushali C Ponde

    2012-01-01

    Full Text Available Neonatal upper limb ischemia due to accidental arterial damage remains a major concern, which can lead to devastating complications if untreated. The primary objective of this case report is to emphasize the role of continuous infraclavicular brachial plexus block, the issues related with block performance in an ischemic hand, and the importance of ultrasound guidance in this particular case scenario. A 1.1 kg infant suffered from distal forearm ischemia due to accidental arterial damage, which was treated with brachial plexus block. An ultrasound-guided single shot block with 0.5 mL/kg of 0.25% bupivacaine was followed by ultrasound-guided catheter placement in the target area. A continuous infusion of 0.03% of bupivacaine at the rate of 0.5 mL/kg/hr (approx. 0.15 mg/kg/h of bupivacaine was administered for 36 h. This treatment resulted in reversal of ischemia. Permanent ischemic damage was eventually confined to the tips of 4 fingers. We conclude that ultrasound-guided continuous infraclavicular block has a therapeutic role to play in the treatment of hand ischemia due to arterial damage and subsequent arterial spasm in neonates with added benefits.

  18. Coenzyme Q10 Protects Hippocampal Neurons Against Ischemia/Reperfusion Injury via Modulation of BAX/Bcl-2 Expression

    Directory of Open Access Journals (Sweden)

    M Zamani

    2012-12-01

    Full Text Available Introduction : Preliminary studies confirmed reduction in cell death following treatment with antioxidants. According to this finding we study the relationship between consumption of CoQ10 and expression of bax and bcl2 in hippocampus following ischemia/reperfusion as proteins involved in cell programmed death or apoptosis.Material & methods : We studied the protective role of CoQ10 against Ischemia-Reperfusion. Experimental design includes four groups: intact, ischemic control, sham control and treatment groups with CoQ10. The mice treated with CoQ10 as Pre - Treatment for a week. Then, ischemia induced by common carotid artery ligation and following the reduction in inflammation (a week the mice post-treated with CoQ10.Nissl staining applied to counting necrotic cells of hippocampus and the western blotting performed to measurement the bax and bcl2 expression.Results :. Cell death was significantly lower when mice treated with CoQ10. Bax expression was significantly high in ischemic group but in treatment group was less and reversely the bcl2 expression in ischemic group was lower than treatment and vehicle groups.Conclusion : Ischemia for 15 minutes induced cell death in hippocampus with more potent effect on CA1. CoQ10 intake significantly reduced cell death and prevented the expression of bax while inducing an increase in expression of bcl2.

  19. Prevention of subsequent exercise-induced periinfarct ischemia by emergency coronary angioplasty in acute myocardial infarction: comparison with intracoronary streptokinase

    International Nuclear Information System (INIS)

    Fung, A.Y.; Lai, P.; Juni, J.E.; Bourdillon, P.D.; Walton, J.A. Jr.; Laufer, N.; Buda, A.J.; Pitt, B.; O'Neill, W.W.

    1986-01-01

    To compare the efficacy of emergency percutaneous transluminal coronary angioplasty and intracoronary streptokinase in preventing exercise-induced periinfarct ischemia, 28 patients presenting within 12 hours of the onset of symptoms of acute myocardial infarction were prospectively randomized. Of these, 14 patients were treated with emergency angioplasty and 14 patients received intracoronary streptokinase. Recatheterization and submaximal exercise thallium-201 single photon emission computed tomography were performed before hospital discharge. Periinfarct ischemia was defined as a reversible thallium defect adjacent to a fixed defect assessed qualitatively. Successful reperfusion was achieved in 86% of patients treated with emergency angioplasty and 86% of patients treated with intracoronary streptokinase (p = NS). Residual stenosis of the infarct-related coronary artery shown at predischarge angiography was 43.8 +/- 31.4% for the angioplasty group and 75.0 +/- 15.6% for the streptokinase group (p less than 0.05). Of the angioplasty group, 9% developed exercise-induced periinfarct ischemia compared with 60% of the streptokinase group (p less than 0.05). Thus, patients with acute myocardial infarction treated with emergency angioplasty had significantly less severe residual coronary stenosis and exercise-induced periinfarct ischemia than did those treated with intracoronary streptokinase. These results suggest further application of coronary angioplasty in the management of acute myocardial infarction

  20. High Field fMRI Reveals Thalamocortical Integration of Segregated Cognitive and Emotional Processing in Mediodorsal and Intralaminar Thalamic Nuclei

    Science.gov (United States)

    Metzger, C. D.; Eckert, U.; Steiner, J.; Sartorius, A.; Buchmann, J. E.; Stadler, J.; Tempelmann, C.; Speck, O.; Bogerts, B.; Abler, B.; Walter, M.

    2010-01-01

    Thalamocortical loops, connecting functionally segregated, higher order cortical regions, and basal ganglia, have been proposed not only for well described motor and sensory regions, but also for limbic and prefrontal areas relevant for affective and cognitive processes. These functions are, however, more specific to humans, rendering most invasive neuroanatomical approaches impossible and interspecies translations difficult. In contrast, non-invasive imaging of functional neuroanatomy using fMRI allows for the development of elaborate task paradigms capable of testing the specific functionalities proposed for these circuits. Until recently, spatial resolution largely limited the anatomical definition of functional clusters at the level of distinct thalamic nuclei. Since their anatomical distinction seems crucial not only for the segregation of cognitive and limbic loops but also for the detection of their functional interaction during cognitive–emotional integration, we applied high resolution fMRI on 7 Tesla. Using an event-related design, we could isolate thalamic effects for preceding attention as well as experience of erotic stimuli. We could demonstrate specific thalamic effects of general emotional arousal in mediodorsal nucleus and effects specific to preceding attention and expectancy in intralaminar centromedian/parafascicular complex. These thalamic effects were paralleled by specific coactivations in the head of caudate nucleus as well as segregated portions of rostral or caudal cingulate cortex and anterior insula supporting distinct thalamo–striato–cortical loops. In addition to predescribed effects of sexual arousal in hypothalamus and ventral striatum, high resolution fMRI could extent this network to paraventricular thalamus encompassing laterodorsal and parataenial nuclei. We could lend evidence to segregated subcortical loops which integrate cognitive and emotional aspects of basic human behavior such as sexual processing. PMID:21088699

  1. High field fMRI reveals thalamocortical integration of segregated cognitive and emotional processing in mediodorsal and intralaminar thalamic nuclei

    Directory of Open Access Journals (Sweden)

    Coraline Danielle Metzger

    2010-11-01

    Full Text Available Thalamocortical loops, connecting functionally segregated, higher order cortical regions and basal ganglia, have been proposed not only for well described motor and sensory regions, but also for limbic and prefrontal areas relevant for affective and cognitive processes. These functions are, however, more specific to humans, rendering most invasive neuroanatomical approaches impossible and interspecies translations difficult. In contrast, non invasive imaging of functional neuroanatomy using fMRI allows for the development of elaborate task paradigms capable of testing the specific functionalities proposed for these circuits. Until recently, spatial resolution largely limited the anatomical definition of functional clusters at the level of distinct thalamic nuclei. Since their anatomical distinction seems crucial not only for the segregation of cognitive and limbic loops but also for the detection of their functional interaction during cognitive-emotional integration, we applied high resolution fMRI on 7 Tesla.Using an event related design, we could isolate thalamic effects for preceding attention as well as experience of erotic stimuli. We could demonstrate specific thalamic effects of general emotional arousal in mediodorsal nucleus and effects specific to preceding attention and expectancy in intralaminar centromedian/parafascicular complex (CM/PF. These thalamic effects were paralleled by specific coactivations in the head of caudate nucleus as well as segregated portions of rostral or caudal cingulate cortex and anterior insula supporting distinct thalamo-striato-cortical loops. In addition to predescribed effects of sexual arousal in hypothalamus and ventral striatum, high resolution fMRI could extent this network to paraventricular thalamus encompassing laterodorsal and parataenial nuclei. We could lend evidence to segregated subcortical loops which integrate cognitive and emotional aspects of basic human behaviour such as sexual

  2. High field FMRI reveals thalamocortical integration of segregated cognitive and emotional processing in mediodorsal and intralaminar thalamic nuclei.

    Science.gov (United States)

    Metzger, C D; Eckert, U; Steiner, J; Sartorius, A; Buchmann, J E; Stadler, J; Tempelmann, C; Speck, O; Bogerts, B; Abler, B; Walter, M

    2010-01-01

    Thalamocortical loops, connecting functionally segregated, higher order cortical regions, and basal ganglia, have been proposed not only for well described motor and sensory regions, but also for limbic and prefrontal areas relevant for affective and cognitive processes. These functions are, however, more specific to humans, rendering most invasive neuroanatomical approaches impossible and interspecies translations difficult. In contrast, non-invasive imaging of functional neuroanatomy using fMRI allows for the development of elaborate task paradigms capable of testing the specific functionalities proposed for these circuits. Until recently, spatial resolution largely limited the anatomical definition of functional clusters at the level of distinct thalamic nuclei. Since their anatomical distinction seems crucial not only for the segregation of cognitive and limbic loops but also for the detection of their functional interaction during cognitive-emotional integration, we applied high resolution fMRI on 7 Tesla. Using an event-related design, we could isolate thalamic effects for preceding attention as well as experience of erotic stimuli. We could demonstrate specific thalamic effects of general emotional arousal in mediodorsal nucleus and effects specific to preceding attention and expectancy in intralaminar centromedian/parafascicular complex. These thalamic effects were paralleled by specific coactivations in the head of caudate nucleus as well as segregated portions of rostral or caudal cingulate cortex and anterior insula supporting distinct thalamo-striato-cortical loops. In addition to predescribed effects of sexual arousal in hypothalamus and ventral striatum, high resolution fMRI could extent this network to paraventricular thalamus encompassing laterodorsal and parataenial nuclei. We could lend evidence to segregated subcortical loops which integrate cognitive and emotional aspects of basic human behavior such as sexual processing.

  3. Cerebral Vasospasm with Ischemia following a Spontaneous Spinal Subarachnoid Hemorrhage

    Directory of Open Access Journals (Sweden)

    Sophia F. Shakur

    2013-01-01

    Full Text Available Cerebral vasospasm is a well-known consequence of aneurysmal subarachnoid hemorrhage (SAH triggered by blood breakdown products. Here, we present the first case of cerebral vasospasm with ischemia following a spontaneous spinal SAH. A 67-year-old woman, who was on Coumadin for atrial fibrillation, presented with chest pain radiating to the back accompanied by headache and leg paresthesias. The international normalized ratio (INR was 4.5. Ten hours after presentation, she developed loss of movement in both legs and lack of sensation below the umbilicus. Spine MRI showed intradural hemorrhage. Her coagulopathy was reversed, and she underwent T2 to T12 laminectomies. A large subarachnoid hematoma was evacuated. Given her complaint of headache preoperatively and the intraoperative finding of spinal SAH, a head CT was done postoperatively that displayed SAH in peripheral sulci. On postoperative day 5, she became obtunded. Brain MRI demonstrated focal restricted diffusion in the left frontoparietal area. Formal angiography revealed vasospasm in anterior cerebral arteries bilaterally and right middle cerebral artery. Vasospasm was treated, and she returned to baseline within 48 hours. Spontaneous spinal SAH can result in the same sequelae typically associated with aneurysmal SAH, and the clinician must have a degree of suspicion in such patients. The pathophysiological mechanisms underlying cerebral vasospasm may explain this unique case.

  4. Schizophrenia-Related Microdeletion Impairs Emotional Memory through MicroRNA-Dependent Disruption of Thalamic Inputs to the Amygdala

    Directory of Open Access Journals (Sweden)

    Tae-Yeon Eom

    2017-05-01

    Full Text Available Individuals with 22q11.2 deletion syndrome (22q11DS are at high risk of developing psychiatric diseases such as schizophrenia. Individuals with 22q11DS and schizophrenia are impaired in emotional memory, anticipating, recalling, and assigning a correct context to emotions. The neuronal circuits responsible for these emotional memory deficits are unknown. Here, we show that 22q11DS mouse models have disrupted synaptic transmission at thalamic inputs to the lateral amygdala (thalamo-LA projections. This synaptic deficit is caused by haploinsufficiency of the 22q11DS gene Dgcr8, which is involved in microRNA processing, and is mediated by the increased dopamine receptor Drd2 levels in the thalamus and by reduced probability of glutamate release from thalamic inputs. This deficit in thalamo-LA synaptic transmission is sufficient to cause fear memory deficits. Our results suggest that dysregulation of the Dgcr8–Drd2 mechanism at thalamic inputs to the amygdala underlies emotional memory deficits in 22q11DS.

  5. Schizophrenia-Related Microdeletion Impairs Emotional Memory through MicroRNA-Dependent Disruption of Thalamic Inputs to the Amygdala.

    Science.gov (United States)

    Eom, Tae-Yeon; Bayazitov, Ildar T; Anderson, Kara; Yu, Jing; Zakharenko, Stanislav S

    2017-05-23

    Individuals with 22q11.2 deletion syndrome (22q11DS) are at high risk of developing psychiatric diseases such as schizophrenia. Individuals with 22q11DS and schizophrenia are impaired in emotional memory, anticipating, recalling, and assigning a correct context to emotions. The neuronal circuits responsible for these emotional memory deficits are unknown. Here, we show that 22q11DS mouse models have disrupted synaptic transmission at thalamic inputs to the lateral amygdala (thalamo-LA projections). This synaptic deficit is caused by haploinsufficiency of the 22q11DS gene Dgcr8, which is involved in microRNA processing, and is mediated by the increased dopamine receptor Drd2 levels in the thalamus and by reduced probability of glutamate release from thalamic inputs. This deficit in thalamo-LA synaptic transmission is sufficient to cause fear memory deficits. Our results suggest that dysregulation of the Dgcr8-Drd2 mechanism at thalamic inputs to the amygdala underlies emotional memory deficits in 22q11DS. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Evidence for thalamic involvement in the thermal grill illusion: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Fredrik Lindstedt

    Full Text Available BACKGROUND: Perceptual illusions play an important role in untangling neural mechanisms underlying conscious phenomena. The thermal grill illusion (TGI has been suggested as a promising model for exploring percepts involved in neuropathic pain, such as cold-allodynia (pain arising from contact with innocuous cold. The TGI is an unpleasant/painful sensation from touching juxtapositioned bars of cold and warm innocuous temperatures. AIM: To develop an MRI-compatible TGI-unit and explore the supraspinal correlates of the illusion, using fMRI, in a group of healthy volunteers. METHODS: We constructed a TGI-thermode allowing the rapid presentation of warm(41°C, cold(18°C and interleaved(41°C+18°C = TGI temperatures in an fMRI-environment. Twenty volunteers were tested. The affective-motivational ("unpleasantness" and sensory-disciminatory ("pain-intensity" dimensions of each respective stimulus were rated. Functional images were analyzed at a corrected α-level <0.05. RESULTS: The TGI was rated as significantly more unpleasant and painful than stimulation with each of its constituent temperatures. Also, the TGI was rated as significantly more unpleasant than painful. Thermal stimulation versus neutral baseline revealed bilateral activations of the anterior insulae and fronto-parietal regions. Unlike its constituent temperatures the TGI displayed a strong activation of the right (contralateral thalamus. Exploratory contrasts at a slightly more liberal threshold-level also revealed a TGI-activation of the right mid/anterior insula, correlating with ratings of unpleasantness (rho = 0.31. CONCLUSION/SIGNIFICANCE: To the best of our knowledge, this is the first fMRI-study of the TGI. The activation of the anterior insula is consistent with this region's putative role in processing of homeostatically relevant feeling-states. Our results constitute the first neurophysiologic evidence of thalamic involvement in the TGI. Similar thalamic activity

  7. Posterior Thalamic Nucleus Modulation of Tactile Stimuli Processing in Rat Motor and Primary Somatosensory Cortices

    Directory of Open Access Journals (Sweden)

    Diana Casas-Torremocha

    2017-09-01

    Full Text Available Rodents move rhythmically their facial whiskers and compute differences between signals predicted and those resulting from the movement to infer information about objects near their head. These computations are carried out by a large network of forebrain structures that includes the thalamus and the primary somatosensory (S1BF and motor (M1wk cortices. Spatially and temporally precise mechanorreceptive whisker information reaches the S1BF cortex via the ventroposterior medial thalamic nucleus (VPM. Other whisker-related information may reach both M1wk and S1BF via the axons from the posterior thalamic nucleus (Po. However, Po axons may convey, in addition to direct sensory signals, the dynamic output of computations between whisker signals and descending motor commands. It has been proposed that this input may be relevant for adjusting cortical responses to predicted vs. unpredicted whisker signals, but the effects of Po input on M1wk and S1BF function have not been directly tested or compared in vivo. Here, using electrophysiology, optogenetics and pharmacological tools, we compared in adult rats M1wk and S1BF in vivo responses in the whisker areas of the motor and primary somatosensory cortices to passive multi-whisker deflection, their dependence on Po activity, and their changes after a brief intense activation of Po axons. We report that the latencies of the first component of tactile-evoked local field potentials in M1wk and S1BF are similar. The evoked potentials decrease markedly in M1wk, but not in S1BF, by injection in Po of the GABAA agonist muscimol. A brief high-frequency electrical stimulation of Po decreases the responsivity of M1wk and S1BF cells to subsequent whisker stimulation. This effect is prevented by the local application of omega-agatoxin, suggesting that it may in part depend on GABA release by fast-spiking parvalbumin (PV-expressing cortical interneurons. Local optogenetic activation of Po synapses in different

  8. Collateral blood flow in different cerebrovascular hierarchy provides endogenous protection in cerebral ischemia.

    Science.gov (United States)

    Luo, Chuanming; Liang, Fengyin; Ren, Huixia; Yao, Xiaoli; Liu, Qiang; Li, Mingyue; Qin, Dajiang; Yuan, Ti-Fei; Pei, Zhong; Su, Huanxing

    2017-11-01

    Collateral blood flow as vascular adaptions to focal cerebral ischemia is well recognized. However, few studies directly investigate the dynamics of collateral vessel recruitment in vivo and little is known about the effect of collateral blood flow in different cerebrovascular hierarchy on the neuropathology after focal ischemic stroke. Here, we report that collateral blood flow is critically involved in blood vessel compensations following regional ischemia. We occluded a pial arteriole using femtosecond laser ablating under the intact thinned skull and documented the changes of collateral flow around the surface communication network and between the surface communication network and subsurface microcirculation network using in vivo two photon microscopy imaging. Occlusion of the pial arteriole apparently increased the diameter and collateral blood flow of its leptomeningeal anastomoses, which significantly reduced the cortical infarction size. This result suggests that the collateral flow via surface communicating network connected with leptomeningeal anastomoses could greatly impact on the extent of infarction. We then further occluded the target pial arteriole and all of its leptomeningeal anastomoses. Notably, this type of occlusion led to reversals of blood flow in the penetrating arterioles mainly proximal to the occluded pial arteriole in a direction from the subsurface microcirculation network to surface arterioles. Interesting, the cell death in the area of ischemic penumbra was accelerated when we performed occlusion to cease the reversed blood flow in those penetrating arterioles, suggesting that the collateral blood flow from subsurface microcirculation network exerts protective roles in delaying cell death in the ischemic penumbra. In conclusion, we provide the first experimental evidence that collateral blood vessels at different cerebrovascular hierarchy are endogenously compensatory mechanisms in brain ischemia. © 2016 International Society of

  9. Managing Reverse Logistics or Reversing Logistics Management?

    NARCIS (Netherlands)

    M.P. de Brito (Marisa)

    2004-01-01

    textabstractIn the past, supply chains were busy fine-tuning the logistics from raw material to the end customer. Today an increasing flow of products is going back in the chain. Thus, companies have to manage reverse logistics as well.This thesis contributes to a better understanding of reverse

  10. Isoflurane administration before ischemia and during reperfusion attenuates ischemia/reperfusion-induced injury of isolated rabbit lungs.

    Science.gov (United States)

    Liu, R; Ishibe, Y; Ueda, M; Hang, Y

    1999-09-01

    To investigate the effects of isoflurane on ischemia/ reperfusion (IR)-induced lung injury, we administered isoflurane before ischemia or during reperfusion. Isolated rabbit lungs were divided into the following groups: control (n = 6), perfused and ventilated for 120 min without ischemia; ISO-control (n = 6), 1 minimum alveolar anesthetic concentration (MAC) isoflurane was administered for 30 min before 120 min continuous perfusion; IR (n = 6), ischemia for 60 min, followed by 60 min reperfusion; IR-ISO1 and IR-ISO2, ischemia followed by reperfusion and 1 MAC (n = 6) or 2 MAC (n = 6) isoflurane for 60 min; ISO-IR (n = 6), 1 MAC isoflurane was administered for 30 min before ischemia, followed by IR. During these maneuvers, we measured total pulmonary vascular resistance (Rt), coefficient of filtration (Kfc), and lung wet to dry ratio (W/D). The results indicated that administration of isoflurane during reperfusion inhibited an IR-induced increase in Kfc and W/D ratio. Furthermore, isoflurane at 2 MAC, but not 1 MAC, significantly inhibited an IR-induced increase in Rt. The administration of isoflurane before ischemia significantly attenuated the increase in IR-induced Kfc, W/D, and Rt. Our results suggest that the administration of isoflurane before ischemia and during reperfusion protects against ischemia-reperfusion-induced injury in isolated rabbit lungs.

  11. Inhaled nitric oxide pretreatment but not posttreatment attenuates ischemia-reperfusion-induced pulmonary microvascular leak.

    Science.gov (United States)

    Chetham, P M; Sefton, W D; Bridges, J P; Stevens, T; McMurtry, I F

    1997-04-01

    Ischemia-reperfusion (I/R) pulmonary edema probably reflects a leukocyte-dependent, oxidant-mediated mechanism. Nitric oxide (NO) attenuates leukocyte-endothelial cell interactions and I/R-induced microvascular leak. Cyclic adenosine monophosphate (cAMP) agonists reverse and prevent I/R-induced microvascular leak, but reversal by inhaled NO (INO) has not been tested. In addition, the role of soluble guanylyl cyclase (sGC) activation in the NO protection effect is unknown. Rat lungs perfused with salt solution were grouped as either I/R, I/R with INO (10 or 50 ppm) on reperfusion, or time control. Capillary filtration coefficients (Kfc) were estimated 25 min before ischemia (baseline) and after 30 and 75 min of reperfusion. Perfusate cell counts and lung homogenate myeloperoxidase activity were determined in selected groups. Additional groups were treated with either INO (50 ppm) or isoproterenol (ISO-10 microM) after 30 min of reperfusion. Guanylyl cyclase was inhibited with 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ-15 microM), and Kfc was estimated at baseline and after 30 min of reperfusion. (1) Inhaled NO attenuated I/R-induced increases in Kfc. (2) Cell counts were similar at baseline. After 75 min of reperfusion, lung neutrophil retention (myeloperoxidase activity) and decreased perfusate neutrophil counts were similar in all groups. (3) In contrast to ISO, INO did not reverse microvascular leak. (4) 8-bromoguanosine 3',5'-cyclic monophosphate (8-br-cGMP) prevented I/R-induced microvascular leak in ODQ-treated lungs, but INO was no longer effective. Inhaled NO attenuates I/R-induced pulmonary microvascular leak, which requires sGC activation and may involve a mechanism independent of inhibition of leukocyte-endothelial cell interactions. In addition, INO is ineffective in reversing I/R-induced microvascular leak.

  12. Association of Thalamic Dysconnectivity and Conversion to Psychosis in Youth and Young Adults at Elevated Clinical Risk

    Science.gov (United States)

    Anticevic, Alan; Haut, Kristen; Murray, John D.; Repovs, Grega; Yang, Genevieve J.; Diehl, Caroline; McEwen, Sarah C.; Bearden, Carrie E.; Addington, Jean; Goodyear, Bradley; Cadenhead, Kristin S.; Mirzakhanian, Heline; Cornblatt, Barbara A.; Olvet, Doreen; Mathalon, Daniel H.; McGlashan, Thomas H.; Perkins, Diana O.; Belger, Aysenil; Seidman, Larry J.; Tsuang, Ming T.; van Erp, Theo G. M.; Walker, Elaine F; Hamann, Stephan; Woods, Scott W; Qiu, Maolin; Cannon, Tyrone D.

    2016-01-01

    IMPORTANCE Severe neuropsychiatric conditions, such as schizophrenia, affect distributed neural computations. One candidate system profoundly altered in chronic schizophrenia involves the thalamocortical networks. It is widely acknowledged that schizophrenia is a neurodevelopmental disorder that likely affects the brain before onset of clinical symptoms. However, no investigation has tested whether thalamocortical connectivity is altered in individuals at risk for psychosis or whether this pattern is more severe in individuals who later develop full-blown illness. OBJECTIVES To determine whether baseline thalamocortical connectivity differs between individuals at clinical high risk for psychosis and healthy controls, whether this pattern is more severe in those who later convert to full-blown illness, and whether magnitude of thalamocortical dysconnectivity is associated with baseline prodromal symptom severity. DESIGN, SETTING, AND PARTICIPANTS In this multicenter, 2-year follow-up, case-control study, we examined 397 participants aged 12–35 years of age (243 individuals at clinical high risk of psychosis, of whom 21 converted to full-blown illness, and 154 healthy controls). The baseline scan dates were January 15, 2010, to April 30, 2012. MAIN OUTCOMES AND MEASURES Whole-brain thalamic functional connectivity maps were generated using individuals’ anatomically defined thalamic seeds, measured using resting-state functional connectivity magnetic resonance imaging. RESULTS Using baseline magnetic resonance images, we identified thalamocortical dysconnectivity in the 243 individuals at clinical high risk for psychosis, which was particularly pronounced in the 21 participants who converted to full-blown illness. The pattern involved widespread hypoconnectivity between the thalamus and prefrontal and cerebellar areas, which was more prominent in those who converted to full-blown illness (t173 = 3.77, P < .001, Hedge g = 0.88). Conversely, there was marked

  13. Reversible Thermoset Adhesives

    Science.gov (United States)

    Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

    2016-01-01

    Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

  14. 99mTc-HMPAO SPECT thalamic blood flow study in migraine

    International Nuclear Information System (INIS)

    Zhang Zhijian; Steiner, T.J.

    1995-01-01

    The changes of blood flow in the thalamic of migraineurs by 99m Tc-HMPAO SPECT imaging are investigated. 60 cases with migraine were performed by Novo 810 high-resolution SPECT 30 minutes after injection of 99m Tc-HMPAO. The quantitative analysis of SPECT data was based on the irregular ROI% uptake normalized to total slice method. There were significantly increased mean % uptake values in migraine with aura (259.1 +-17.1), and more significantly in those who experienced hemisensory symptoms and hemiparesis during aura (263.8 +- 17.2), compared to that of migraine without aura (249.1 +- 14.9), but there were not statistically significant difference between migraine with only visual disturbance during aura (255.1 +- 16.4) and without aura. The possible explanations for the increased mean % uptake values in migraineurs who experienced hemisensory symptoms and hemiparesis during aura are: (1) the reactive postischemic hyperemia. (2) excepting thalamus, the regional blood flow was decreased. (3) the secondary phenomenon to the various neurogenic and chemical stimuli

  15. Aphasia following left thalamic hemorrhage. A study by Western Aphasia Battery and single photon emission CT

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    Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro

    1984-07-01

    A report is given of 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months) in which language disorders were examined by Western Aphasia Battery (WAB) and cerebral blood flow was measured by single photon emission CT. Examination of language by WAB revealed 4 aphasics out of 7 cases, and 3 patients had no language deficit. The patient with Wernicke's aphasia showed low density area only in the left posterior thalamus in X-ray CT, and revealed severe low blood flow area extending to left temporal lobe in emission CT. In the case with transcortical sensory aphasia, although X-ray CT showed no obvious low density area, emission CT revealed moderate low flow area in the left temporooccipital region and low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, emission CT showed slight low flow area at the temporo-occipital region similar to the case with transcortical sensory aphasia. In another case with anomic aphasia there was a wide low density area all over the left thalamus and midline shift to the right in X-ray CT, and emission CT showed severe low blood flow in the same region spreading widely toward the cerebral surface. In all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus.

  16. Amygdalar, hippocampal, and thalamic volumes in youth at high risk for development of bipolar disorder.

    Science.gov (United States)

    Karchemskiy, Asya; Garrett, Amy; Howe, Meghan; Adleman, Nancy; Simeonova, Diana I; Alegria, Dylan; Reiss, Allan; Chang, Kiki

    2011-12-30

    Children of parents with bipolar disorder (BD), especially those with attention deficit hyperactivity disorder (ADHD) and symptoms of depression or mania, are at significantly high risk for developing BD. As we have previously shown amygdalar reductions in pediatric BD, the current study examined amygdalar volumes in offspring of parents (BD offspring) who have not yet developed a full manic episode. Youth participating in the study included 22 BD offspring and 22 healthy controls of comparable age, gender, handedness, and IQ. Subjects had no history of a manic episode, but met criteria for ADHD and moderate mood symptoms. MRI was performed on a 3T GE scanner, using a 3D volumetric spoiled gradient echo series. Amygdalae were manually traced using BrainImage Java software on positionally normalized brain stacks. Bipolar offspring had similar amygdalar volumes compared to the control group. Exploratory analyses yielded no differences in hippocampal or thalamic volumes. Bipolar offspring do not show decreased amygdalar volume, possibly because these abnormalities occur after more prolonged illness rather than as a preexisting risk factor. Longitudinal studies are needed to determine whether amygdalar volumes change during and after the development of BD. 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Thalamic reticular impairment underlies attention deficit in Ptchd1(Y/-) mice.

    Science.gov (United States)

    Wells, Michael F; Wimmer, Ralf D; Schmitt, L Ian; Feng, Guoping; Halassa, Michael M

    2016-04-07

    Developmental disabilities, including attention-deficit hyperactivity disorder (ADHD), intellectual disability (ID), and autism spectrum disorders (ASD), affect one in six children in the USA. Recently, gene mutations in patched domain containing 1 (PTCHD1) have been found in ~1% of patients with ID and ASD. Individuals with PTCHD1 deletion show symptoms of ADHD, sleep disruption, hypotonia, aggression, ASD, and ID. Although PTCHD1 is probably critical for normal development, the connection between its deletion and the ensuing behavioural defects is poorly understood. Here we report that during early post-natal development, mouse Ptchd1 is selectively expressed in the thalamic reticular nucleus (TRN), a group of GABAergic neurons that regulate thalamocortical transmission, sleep rhythms, and attention. Ptchd1 deletion attenuates TRN activity through mechanisms involving small conductance calcium-dependent potassium currents (SK). TRN-restricted deletion of Ptchd1 leads to attention deficits and hyperactivity, both of which are rescued by pharmacological augmentation of SK channel activity. Global Ptchd1 deletion recapitulates learning impairment, hyper-aggression, and motor defects, all of which are insensitive to SK pharmacological targeting and not found in the TRN-restricted deletion mouse. This study maps clinically relevant behavioural phenotypes onto TRN dysfunction in a human disease model, while also identifying molecular and circuit targets for intervention.

  18. Pontine and Thalamic Influences on Fluid Rewards: I. Operant Responding for Sucrose and Corn Oil

    Science.gov (United States)

    Liang, Nu-Chu; Freet, Christopher S.; Grigson, Patricia S; Norgren, Ralph

    2011-01-01

    The reward strength of orosensory sucrose and corn oil was measured using fixed and progressive ratio operant schedules. Because the orosensory effects of the stimuli were of interest, Experiment 1 compared operant responses for sucrose in sham and real feeding rats. The results demonstrated that rats would work for sucrose solutions without the accompanying postingestive effects. Furthermore, the break points for high concentrations of sucrose (1.0 M or 2.0 M) were significantly higher in sham feeding rats than in real feeding controls. Experiment 2 investigated the role of the parabrachial nucleus (PBN) and of the thalamic orosensory area (TOA) in sucrose and corn oil reward. During free access, rats with PBN lesions (PBNx) licked significantly less sucrose solution than their controls, but both groups ingested a similar volume of corn oil emulsion. When an operant was imposed, these same PBNx rats failed to respond for sucrose and continued only modestly for corn oil. In contrast, the TOA lesioned rats (TOAx) showed no impairment in responding for sucrose or corn oil during either the free access or operant sessions. Furthermore, rats with TOA lesions demonstrated significantly higher break points for sucrose than did their controls. Together, the data imply that the PBN but not the TOA is critical for the perception of, or responding to the reward value of sucrose and corn oil. PMID:21703290

  19. Corticothalamic Synaptic Noise as a Mechanism for Selective Attention in Thalamic Neurons

    Science.gov (United States)

    Béhuret, Sébastien; Deleuze, Charlotte; Bal, Thierry

    2015-01-01

    A reason why the thalamus is more than a passive gateway for sensory signals is that two-third of the synapses of thalamocortical neurons are directly or indirectly related to the activity of corticothalamic axons. While the responses of thalamocortical neurons evoked by sensory stimuli are well characterized, with ON- and OFF-center receptive field structures, the prevalence of synaptic noise resulting from neocortical feedback in intracellularly recorded thalamocortical neurons in vivo has attracted little attention. However, in vitro and modeling experiments point to its critical role for the integration of sensory signals. Here we combine our recent findings in a unified framework suggesting the hypothesis that corticothalamic synaptic activity is adapted to modulate the transfer efficiency of thalamocortical neurons during selective attention at three different levels: First, on ionic channels by interacting with intrinsic membrane properties, second at the neuron level by impacting on the input-output gain, and third even more effectively at the cell assembly level by boosting the information transfer of sensory features encoded in thalamic subnetworks. This top-down population control is achieved by tuning the correlations in subthreshold membrane potential fluctuations and is adapted to modulate the transfer of sensory features encoded by assemblies of thalamocortical relay neurons. We thus propose that cortically-controlled (de-)correlation of subthreshold noise is an efficient and swift dynamic mechanism for selective attention in the thalamus. PMID:26733818

  20. Corticothalamic Synaptic Noise as a Mechanism for Selective Attention in Thalamic Neurons.

    Science.gov (United States)

    Béhuret, Sébastien; Deleuze, Charlotte; Bal, Thierry

    2015-01-01

    A reason why the thalamus is more than a passive gateway for sensory signals is that two-third of the synapses of thalamocortical neurons are directly or indirectly related to the activity of corticothalamic axons. While the responses of thalamocortical neurons evoked by sensory stimuli are well characterized, with ON- and OFF-center receptive field structures, the prevalence of synaptic noise resulting from neocortical feedback in intracellularly recorded thalamocortical neurons in vivo has attracted little attention. However, in vitro and modeling experiments point to its critical role for the integration of sensory signals. Here we combine our recent findings in a unified framework suggesting the hypothesis that corticothalamic synaptic activity is adapted to modulate the transfer efficiency of thalamocortical neurons during selective attention at three different levels: First, on ionic channels by interacting with intrinsic membrane properties, second at the neuron level by impacting on the input-output gain, and third even more effectively at the cell assembly level by boosting the information transfer of sensory features encoded in thalamic subnetworks. This top-down population control is achieved by tuning the correlations in subthreshold membrane potential fluctuations and is adapted to modulate the transfer of sensory features encoded by assemblies of thalamocortical relay neurons. We thus propose that cortically-controlled (de-)correlation of subthreshold noise is an efficient and swift dynamic mechanism for selective attention in the thalamus.

  1. Gait Balance Disorder by Thalamic Infarction with the Disorder of Interstitial Nucleus of Cajal

    Science.gov (United States)

    Kurosu, A.; Hayashi, Y.; Wada, K.; Nagaoka, M.

    2011-01-01

    The interstitial nucleus of Cajal (INC) is thought to play an important role in torsional/vertical eye position and head posture, and disorders of the INC induce abnormal ocular movements and head tilt. Our patients with ocular tilt reactions simultaneously also had disturbances in ambulatory balance, yet no reports address the loss of balance control induced by disorders of the INC. We examined the ambulatory disturbances induced by INC lesion. We experienced three patients with ocular movement disorders and abnormal head tilt due to thalamic infarction. We performed ophthalmic examinations on and checked the balance of them. With funduscopy, abnormal cycloduction was seen in the unaffected side and normal cycloduction was observed in the affected side. Nevertheless, Hess charts showed distortions in the visual image of both eyes. They all had disorders of balance control. We tried to treat them using the Bobath approach for improving their ambulatory balance. With subsequent improvements in balance control it was possible for them to take short walks, but it was difficult to make any improvements in their ocular movement. The INC is related to balance control of ambulation and disorders of the INC induce ambulatory disturbances. Cycloduction was only observed in the unaffected side, but Hess charts showed distortions of the visual image in both eyes. Ambulation was briefly improved, but diplopia persisted in these patients. PMID:21769260

  2. Gait Balance Disorder by Thalamic Infarction with the Disorder of Interstitial Nucleus of Cajal

    Directory of Open Access Journals (Sweden)

    A. Kurosu

    2011-01-01

    Full Text Available The interstitial nucleus of Cajal (INC is thought to play an important role in torsional/vertical eye position and head posture, and disorders of the INC induce abnormal ocular movements and head tilt. Our patients with ocular tilt reactions simultaneously also had disturbances in ambulatory balance, yet no reports address the loss of balance control induced by disorders of the INC. We examined the ambulatory disturbances induced by INC lesion. We experienced three patients with ocular movement disorders and abnormal head tilt due to thalamic infarction. We performed ophthalmic examinations on and checked the balance of them. With funduscopy, abnormal cycloduction was seen in the unaffected side and normal cycloduction was observed in the affected side. Nevertheless, Hess charts showed distortions in the visual image of both eyes. They all had disorders of balance control. We tried to treat them using the Bobath approach for improving their ambulatory balance. With subsequent improvements in balance control it was possible for them to take short walks, but it was difficult to make any improvements in their ocular movement. The INC is related to balance control of ambulation and disorders of the INC induce ambulatory disturbances. Cycloduction was only observed in the unaffected side, but Hess charts showed distortions of the visual image in both eyes. Ambulation was briefly improved, but diplopia persisted in these patients.

  3. Distinct Thalamic Reticular Cell Types Differentially Modulate Normal and Pathological Cortical Rhythms

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    Alexandra Clemente-Perez

    2017-06-01

    Full Text Available Integrative brain functions depend on widely distributed, rhythmically coordinated computations. Through its long-ranging connections with cortex and most senses, the thalamus orchestrates the flow of cognitive and sensory information. Essential in this process, the nucleus reticularis thalami (nRT gates different information streams through its extensive inhibition onto other thalamic nuclei, however, we lack an understanding of how different inhibitory neuron subpopulations in nRT function as gatekeepers. We dissociated the connectivity, physiology, and circuit functions of neurons within rodent nRT, based on parvalbumin (PV and somatostatin (SOM expression, and validated the existence of such populations in human nRT. We found that PV, but not SOM, cells are rhythmogenic, and that PV and SOM neurons are connected to and modulate distinct thalamocortical circuits. Notably, PV, but not SOM, neurons modulate somatosensory behavior and disrupt seizures. These results provide a conceptual framework for how nRT may gate incoming information to modulate brain-wide rhythms.

  4. Neurons in the thalamic reticular nucleus are selective for diverse and complex visual features

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    Vishal eVaingankar

    2012-12-01

    Full Text Available All visual signals the cortex receives are influenced by the perigeniculate sector of the thalamic reticular nucleus, which receives input from relay cells in the lateral geniculate and provides feedback inhibition in return. Relay cells have been studied in quantitative depth; they behave in a roughly linear fashion and have receptive fields with a stereotyped centre-surround structure. We know far less about reticular neurons. Qualitative studies indicate they simply pool ascending input to generate nonselective gain control. Yet the perigeniculate is complicated; local cells are densely interconnected and fire lengthy bursts. Thus, we employed quantitative methods to explore the perigeniculate, using relay cells as controls. By adapting methods of spike-triggered averaging and covariance analysis for bursts, we identified both first and second order features that build reticular receptive fields. The shapes of these spatiotemporal subunits varied widely; no stereotyped pattern emerged. Companion experiments showed that the shape of the first but not second order features could be explained by the overlap of On and Off inputs to a given cell. Moreover, we assessed the predictive power of the receptive field and how much information each component subunit conveyed. Linear-nonlinear models including multiple subunits performed better than those made with just one; further each subunit encoded different visual information. Model performance for reticular cells was always lesser than for relay cells, however, indicating that reticular cells process inputs nonlinearly. All told, our results suggest that the perigeniculate encodes diverse visual features to selectively modulate activity transmitted downstream

  5. Quantitative methods for evaluating the efficacy of thalamic deep brain stimulation in patients with essential tremor.

    Science.gov (United States)

    Wastensson, Gunilla; Holmberg, Björn; Johnels, Bo; Barregard, Lars

    2013-01-01

    Deep brain stimulation (DBS) of the thalamus is a safe and efficient method for treatment of disabling tremor in patient with essential tremor (ET). However, successful tremor suppression after surgery requires careful selection of stimulus parameters. Our aim was to examine the possible use of certain quantitative methods for evaluating the efficacy of thalamic DBS in ET patients in clinical practice, and to compare these methods with traditional clinical tests. We examined 22 patients using the Essential Tremor Rating Scale (ETRS) and quantitative assessment of tremor with the stimulator both activated and deactivated. We used an accelerometer (CATSYS tremor Pen) for quantitative measurement of postural tremor, and a eurythmokinesimeter (EKM) to evaluate kinetic tremor in a rapid pointing task. The efficacy of DBS on tremor suppression was prominent irrespective of the method used. The agreement between clinical rating of postural tremor and tremor intensity as measured by the CATSYS tremor pen was relatively high (rs = 0.74). The agreement between kinetic tremor as assessed by the ETRS and the main outcome variable from the EKM test was low (rs = 0.34). The lack of agreement indicates that the EKM test is not comparable with the clinical test. Quantitative methods, such as the CATSYS tremor pen, could be a useful complement to clinical tremor assessment in evaluating the efficacy of DBS in clinical practice. Future studies should evaluate the precision of these methods and long-term impact on tremor suppression, activities of daily living (ADL) function and quality of life.

  6. Neural signal for counteracting pre-action bias in the centromedian thalamic nucleus

    Directory of Open Access Journals (Sweden)

    Takafumi eMinamimoto

    2014-01-01

    Full Text Available Most of our daily actions are selected and executed involuntarily under familiar situations by the guidance of internal drives, such as motivation. The behavioral tendency or biasing towards one over others reflects the action-selection process in advance of action execution (i.e., pre-action bias. Facing unexpected situations, however, pre-action bias should be withdrawn and replaced by an alternative that is suitable for the situation (i.e., counteracting bias. To understand the neural mechanism for the counteracting process, we studied the neural activity of the thalamic centromedian (CM nucleus in monkeys performing GO-NOGO task with asymmetrical or symmetrical reward conditions. The monkeys reacted to GO signal faster in large-reward condition, indicating behavioral bias toward large reward. In contrast, they responded slowly in small-reward condition, suggesting a conflict between internal drive and external demand. We found that neurons in the CM nucleus exhibited phasic burst discharges after GO and NOGO instructions especially when they were associated with small reward. The small-reward preference was positively correlated with the strength of behavioral bias toward large reward. The small-reward preference disappeared when only NOGO action was requested. The timing of activation predicted the timing of action opposed to bias. These results suggest that CM signals the discrepancy between internal pre-action bias and external demand, and mediates the counteracting process — resetting behavioral bias and leading to execution of opposing action.

  7. Isolated amnesia following a bilateral paramedian thalamic infarct. Possible etiologic role of a whiplash injury.

    Science.gov (United States)

    Barontini, F; Maurri, S

    1992-04-01

    A previously healthy 45 years old carpenter suffered a whiplash injury in a road accident on July, 18th, 1990. He continued to work in spite of occipital headache, episodic sweatening and slight hypersomnia. On August, 8th, 1990 while parking his car into the deck of a ferry-boat he was found slightly confuse and markedly amnestic. A post-traumatic subdural haematoma was suspected. As a CT-scan of the brain was normal, a toxic encephalopathy or an hysterical amnesia were proposed. However, a MRI performed on August, 22th, 1990, apart from a small infarct in the white matter of the left occipital lobe, showed two small bilateral paramedian thalamic infarcts. The last lesions usually follow a thrombotic or embolic occlusion of the "basilar communicating artery" (BCA) belonging to the vertebro-basilar system. The possible etiologic relationship between this syndrome and the previous whiplash injury has been considered. Six months later, while a control MRI showed a reduction of the brain lesions, a neuropsychological examination revealed a slight improvement of memory dysfunction evident also at a distance of further 6 months. This case is interesting because it tests the high sensitivity of MRI in amnestic syndromes and because of the possible role of a whiplash injury in the etiology of BPTI.

  8. The slow oscillation in cortical and thalamic networks: mechanisms and functions

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    Garrett T. Neske

    2016-01-01

    Full Text Available During even the most quiescent behavioral periods, the cortex and thalamus express rich spontaneous activity in the form of slow (<1 Hz, synchronous network state transitions. Throughout this so-called slow oscillation, cortical and thalamic neurons fluctuate between periods of intense synaptic activity (Up states and almost complete silence (Down states. The two decades since the original characterization of the slow oscillation in the cortex and thalamus have seen considerable advances in deciphering the cellular and network mechanisms associated with this pervasive phenomenon. There are, nevertheless, many questions regarding the slow oscillation that await more thorough illumination, particularly the mechanisms by which Up states initiate and terminate, the functional role of the rhythmic activity cycles in unconscious or minimally conscious states, and the precise relation between Up states and the activated states associated with waking behavior. Given the substantial advances in multineuronal recording and imaging methods in both in vivo and in vitro preparations, the time is ripe to take stock of our current understanding of the slow oscillation and pave the way for future investigations of its mechanisms and functions. My aim in this Review is to provide a comprehensive account of the mechanisms and functions of the slow oscillation, and to suggest avenues for further exploration.

  9. Simple cortical and thalamic neuron models for digital arithmetic circuit implementation

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    Takuya eNanami

    2016-05-01

    Full Text Available Trade-off between reproducibility of neuronal activities and computational efficiency is one ofcrucial subjects in computational neuroscience and neuromorphic engineering. A wide variety ofneuronal models have been studied from different viewpoints. The digital spiking silicon neuron(DSSN model is a qualitative model that focuses on efficient implementation by digital arithmeticcircuits. We expanded the DSSN model and found appropriate parameter sets with which itreproduces the dynamical behaviors of the ionic-conductance models of four classes of corticaland thalamic neurons. We first developed a 4-variable model by reducing the number of variablesin the ionic-conductance models and elucidated its mathematical structures using bifurcationanalysis. Then, expanded DSSN models were constructed that reproduce these mathematicalstructures and capture the characteristic behavior of each neuron class. We confirmed thatstatistics of the neuronal spike sequences are similar in the DSSN and the ionic-conductancemodels. Computational cost of the DSSN model is larger than that of the recent sophisticatedIntegrate-and-Fire-based models, but smaller than the ionic-conductance models. This modelis intended to provide another meeting point for above trade-off that satisfies the demand forlarge-scale neuronal network simulation with closer-to-biology models.

  10. Corticothalamic Synaptic Noise as a Mechanism for Selective Attention in Thalamic Neurons

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    Sébastien eBéhuret

    2015-12-01

    Full Text Available A reason why the thalamus is more than a passive gateway for sensory signals is that two-third of the synapses of thalamocortical neurons are directly or indirectly related to the activity of corticothalamic axons. While the responses of thalamocortical neurons evoked by sensory stimuli are well characterized, with ON- and OFF-center receptive field structures, the prevalence of synaptic noise resulting from neocortical feedback in intracellularly recorded thalamocortical neurons in vivo has attracted little attention. However, in vitro and modeling experiments point to its critical role for the integration of sensory signals. Here we combine our recent findings in a unified framework suggesting the hypothesis that corticothalamic synaptic activity is adapted to modulate the transfer efficiency of thalamocortical neurons during selective attention at three different levels: First, on ionic channels by interacting with intrinsic membrane properties, second at the neuron level by impacting on the input-output gain, and third even more effectively at the cell assembly level by boosting the information transfer of sensory features encoded in thalamic subnetworks. This top-down population control is achieved by tuning the correlations in subthreshold membrane potential fluctuations and is adapted to modulate the transfer of sensory features encoded by assemblies of thalamocortical relay neurons. We thus propose that cortically-controlled (de-correlation of subthreshold noise is an efficient and swift dynamic mechanism for selective attention in the thalamus.

  11. Magnetic resonance imaging of experimental cerebral ischemia

    International Nuclear Information System (INIS)

    Kato, Hiroyuki; Kogure, Kyuya; Ohtomo, Hitoshi

    1986-01-01

    In the spectroscopic experiment on excised rat brain (cortex, white matter, hippocampus and thalamus for normal and ischemia-laden brain), T1 and T2 relaxation times and water content were determined. The ischemic insult was induced for 60 min by the method of Pulsinelli followed by 60 min of reperfusion. All of the T1, T2, and water content significantly increased in the ischemic tissue. Gray-white difference was evident in T1 and T1 was linearly correlated with the water content of the tissue. T2 way by far prolonged in the ischemic tissue compared with the increase in the water content, showing greater sensitivity of T2 for detection of ischemia. In the imaging experiment, coronal NMR imaging at 0.5 tesla was performed employing proton density-weighted saturation recovery (TR = 1.6 s, TE = 14 ms), T1-weighted inversion recovery (TR = 1.6 s, TI = 300 ms, TE = 14 ms) and T2-weighted spin echo (TR = 1.6 s, TE = 106 ms) pulse sequences. Spatial resolution of the images was excellent (0.3 - 0.5 mm) and the imaging of a gerbil brain clearly delineated anatomy separating cortex, white matter, hippocampus and thalamus. Hemispheric ischemia of a gerbil brain was detected as early as 30 min after occlusion of the carotid artery in T2-weighted images and the evolution of the lesion was clearly picturized in T1- and T2-weighted images. On the other hand. SR images were far less sensitive. Caluculated T1 and T2 relaxation times by the pixel-to-pixel computation indicated progress of the lesion and excellently correlated with the water content of the tissue (r = 0.892 and 0.744 for T1 and T2, respectively). (J.P.N.)

  12. Anterior Segment Ischemia after Strabismus Surger

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    Emine Seyhan Göçmen

    2017-01-01

    Full Text Available A 46-year-old male patient was referred to our clinic with complaints of diplopia and esotropia in his right eye that developed after a car accident. The patient had right esotropia in primary position and abduction of the right eye was totally limited. Primary deviation was over 40 prism diopters at near and distance. The patient was diagnosed with sixth nerve palsy and 18 months after trauma, he underwent right medial rectus muscle recession. Ten months after the first operation, full-thickness tendon transposition of the superior and inferior rectus muscles (with Foster suture was performed. On the first postoperative day, slit-lamp examination revealed corneal edema, 3+ cells in the anterior chamber and an irregular pupil. According to these findings, the diagnosis was anterior segment ischemia. Treatment with 0.1/5 mL topical dexamethasone drops (16 times/day, cyclopentolate hydrochloride drops (3 times/day and 20 mg oral fluocortolone (3 times/day was initiated. After 1 week of treatment, corneal edema regressed and the anterior chamber was clean. Topical and systemic steroid treatment was gradually discontinued. At postoperative 1 month, the patient was orthophoric and there were no pathologic symptoms besides the irregular pupil. Anterior segment ischemia is one of the most serious complications of strabismus surgery. Despite the fact that in most cases the only remaining sequel is an irregular pupil, serious circulation deficits could lead to phthisis bulbi. Clinical properties of anterior segment ischemia should be well recognized and in especially risky cases, preventative measures should be taken.

  13. Cocaine-associated lower limb ischemia.

    LENUS (Irish Health Repository)

    Collins, Chris G

    2011-07-25

    Cocaine-associated thrombosis has been reported in the literature with reports of vascular injuries to cardiac, pulmonary, intestinal, placental, and musculoskeletal vessels; however, injury of the pedal vessels is rare. We report on a 31-year-old man who presented 2 months following a cocaine binge with limb-threatening ischemia without an otherwise identifiable embolic source. Angiography confirmed extensive occlusive disease of the tibioperoneal vessels. The patient improved following therapy with heparin and a prostacyclin analogue. Cocaine-induced thrombosis should be considered in patients presenting with acute arterial insufficiency in the lower limb without any other identifiable cause.

  14. Silent ischemia and beta-blockade

    DEFF Research Database (Denmark)

    Egstrup, K

    1991-01-01

    and should also be directed at the other coronary artery risk factors of the patients. The effects of beta-blockers, which reduce the duration and frequency of silent ischemic episodes, is well described. The effect is most pronounced in the morning, when the frequency of ischemia is highest......, and the mechanism of action seems mainly mediated through a reduction in myocardial oxygen demand. beta-Blockers have shown effectiveness in both effort-induced angina and mixed angina, and increased anti-ischemic potency may be achieved by combination therapy with a calcium antagonist. Abrupt withdrawal of beta-blockers...

  15. Oxidative stress in ischemia and reperfusion

    DEFF Research Database (Denmark)

    Sinning, Christoph; Westermann, Dirk; Clemmensen, Peter

    2017-01-01

    Oxidative stress remains a major contributor to myocardial injury after ischemia followed by reperfusion (I/R) as the reperfusion of the myocardial infarction (MI) area inevitably leads to a cascade of I/R injury. This review focused on concepts of the antioxidative defense system and elucidates......, the different mechanisms through which myocardial protection can be addressed, like ischemic postconditioning in myocardial infarction or adjunctive measures like targeted temperature management as well as new theories, including the role of iron in I/R injury, will be discussed....

  16. Intracoronary levosimendan during ischemia prevents myocardial apoptosis.

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    Markus eMalmberg

    2012-02-01

    Full Text Available Background. Levosimendan is a calcium-sensitizing inotropic agent that prevents myocardial contractile depression following cardiac surgery. Levosimendan has also anti-apoptotic properties, but the role of this mechanism is not clear. We studied whether levosimendan prevents cardiomyocyte apoptosis and post-operative stunning after either intracoronary administration or intravenous infusion in an experimental model. Methods. Pigs (n=24 were subjected to 40 minutes of global, cardioplegic ischemia under cardiopulmonary bypass and 240 minutes of reperfusion. L-IV group received intravenous infusion of levosimendan (65 μg/kg 40 minutes before ischemia and L-IC group received levosimendan (65 μg/kg during ischemia administered intracoronary. Control group was operated without levosimendan. Echocardiography was performed to all animals. Apoptosis was determined from transmyocardial biopsies taken from left ventricle using TUNEL assay and immunohistochemistry of active caspace-3. Results. Apoptosis was induced after ischemia-reperfusion in all groups (pre L-IV 0.002±0.004 % vs. post L-IV 0.020±0.017 % p=0.02, pre L-IC 0.001±0.004 % vs. post L-IC 0.020±0.017 % p<0.001, pre control 0.007±0.013 % vs. post control 0.062±0.044 % p=0.01. The amount of apoptosis was higher in the controls, compared with the L-IV (p=0.03 and the L-IC (p=0.03 groups. Longitudinal left ventricular contraction was significantly reduced in the L-IC and the control groups when compared to the L-IV group (L-IV 0.75±0.12 mm vs. L-IC 0.53±0.11 mm p=0.003, L-IV vs. control 0.54±0.11 p=0.01. Conclusions. Both intracoronary administration and pre-ischemic intravenous infusion of levosimendan equally prevented apoptosis, but intravenous administration was required for optimal preservation of the post-operative systolic left ventricle function.

  17. Tubal Ligation Reversal

    Science.gov (United States)

    ... seal off the fallopian tubes, such as the Essure or Adiana systems, generally aren't reversible. Why ... electrocautery). Some types of sterilization, such as the Essure or Adiana systems, aren't considered reversible. Risks ...

  18. Review on herbal medicine on brain ischemia and reperfusion简

    Institute of Scientific and Technical Information of China (English)

    Nahid; Jivad; Zahra; Rabiei

    2015-01-01

    Brain ischemia and reperfusion is the leading cause of serious and long-range disability in the world. Clinically significant changes in central nervous system function are observed following brain ischemia and reperfusion. Stroke patients exhibit behavioral, cognitive,emotional, affective and electrophysiological changes during recovery phase. Brain injury by transient complete global brain ischemia or by transient incomplete brain ischemia afflicts a very large number of patients in the world with death or permanent disability. In order to reduce this damage, we must sufficiently understand the mechanisms involved in brain ischemia and reperfusion and repair to design clinically effective therapy.Cerebral ischemia and reperfusion is known to induce the generation of reactive oxygen species that can lead to oxidative damage of proteins, membrane lipids and nucleic acids.A decrease in tissue antioxidant capacity, an increase in lipid peroxidation as well as an increase in lipid peroxidation inhibitors have been demonstrated in several models of brain ischemia. This paper reviews the number of commonly used types of herbal medicines effective for the treatment of stroke. The aim of this paper was to review evidences from controlled studies in order to discuss whether herbal medicine can be helpful in the treatment of brain ischemia and reperfusion.

  19. Influence of prolonged cold ischemia in renal transplantation.

    NARCIS (Netherlands)

    Vliet, J.A. van der; Warle, M.C.; Cheung, C.L.; Teerenstra, S.; Hoitsma, A.J.

    2011-01-01

    van der Vliet JA, Warle MC, Cheung CLS, Teerenstra S, Hoitsma AJ. Influence of prolonged cold ischemia in renal transplantation. Clin Transplant 2011: 25: E612-E616. (c) 2011 John Wiley & Sons A/S. Abstract: Aim: To determine to what extent current cold ischemia times (CITs) affect the results of

  20. CSF transthyretin neuroprotection in a mouse model of brain ischemia

    DEFF Research Database (Denmark)

    Santos, Sofia Duque; Lambertsen, Kate Lykke; Clausen, Bettina Hjelm

    2010-01-01

    Brain injury caused by ischemia is a major cause of human mortality and physical/cognitive disability worldwide. Experimentally, brain ischemia can be induced surgically by permanent middle cerebral artery occlusion. Using this model, we studied the influence of transthyretin in ischemic stroke. ...

  1. Ergotamine-induced upper extremity ischemia: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Man Deuk; Lee, Gun [Bundang CHA General Hospital, Pochon (China); Shin, Sung Wook [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2005-06-15

    Ergotamine-induced limb ischemia is an extremely rare case. We present a case of a 64-year-old man, who developed ischemia on the right upper extremity due to long-term use of Ergot for migraine headache. Angiography revealed diffused, smooth, and tapered narrowing of the brachial artery. The patient was successfully treated with intravenous nitroprusside.

  2. Reverse logistics - a framework

    NARCIS (Netherlands)

    M.P. de Brito (Marisa); R. Dekker (Rommert)

    2002-01-01

    textabstractIn this paper we define and compare Reverse Logistics definitions. We start by giving an understanding framework of Reverse Logistics: the why-what-how. By this means, we put in context the driving forces for Reverse Logistics, a typology of return reasons, a classification of

  3. Bilateral thalamic stroke due to occlusion of the artery of Percheron in a patient with patent foramen ovale: a case report

    Directory of Open Access Journals (Sweden)

    López-Serna Raúl

    2009-09-01

    Full Text Available Abstract Introduction Bilateral thalamic infarcts are rare presentations of stroke. They are the result of a complex combination of risk factors and a predisposing vessel distribution. The artery of Percheron, characterized by a single arterial trunk that irrigates both paramedian thalamic regions, can be occluded as a result of embolic diseases leading to bilateral paramedian thalamic infarcts. Clinical and image findings of this uncommon form of posterior circulation infarct are presented along with their anatomic and pathophysiologic correlates. Case presentation A 27-year-old Mexican man with no relevant medical history was admitted to hospital after he was found deeply stuporous. On admission, an urgent neuroimaging protocol for stroke, including magnetic resonance imaging and magnetic resonance imaging angiography, was performed. The scans revealed symmetric bilateral hyperintense paramedian thalamic lesions consistent with acute ischemic events. The posterior circulation was patent including the tip of the basilar artery and both posterior cerebral arteries, making the case compatible with occlusion of the artery of Percheron. Further evaluation with an aim to define the etiology revealed a patent foramen ovale as the cause of embolism. Conclusion Bilateral thalamic infarcts are unusual presentations of posterior circulation stroke; once they are diagnosed by an adequate neuroimaging protocol, a further evaluation to define the cause is necessary. Cardioembolism should always be considered in relatively young patients. A complete evaluation should be conducted by an interdisciplinary team including neurologists, cardiologists and neurosurgeons.

  4. Neurochemical pathways that converge on thalamic trigeminovascular neurons: potential substrate for modulation of migraine by sleep, food intake, stress and anxiety.

    Directory of Open Access Journals (Sweden)

    Rodrigo Noseda

    Full Text Available Dynamic thalamic regulation of sensory signals allows the cortex to adjust better to rapidly changing behavioral, physiological and environmental demands. To fulfill this role, thalamic neurons must themselves be subjected to constantly changing modulatory inputs that originate in multiple neurochemical pathways involved in autonomic, affective and cognitive functions. Our overall goal is to define an anatomical framework for conceptualizing how a 'decision' is made on whether a trigeminovascular thalamic neuron fires, for how long, and at what frequency. To begin answering this question, we determine which neuropeptides/neurotransmitters are in a position to modulate thalamic trigeminovascular neurons. Using a combination of in-vivo single-unit recording, juxtacellular labeling with tetramethylrhodamine dextran (TMR and in-vitro immunohistochemistry, we found that thalamic trigeminovascular neurons were surrounded by high density of axons containing biomarkers of glutamate, GABA, dopamine and serotonin; moderate density of axons containing noradrenaline and histamine; low density of axons containing orexin and melanin concentrating hormone (MCH; but not axons containing CGRP, serotonin 1D receptor, oxytocin or vasopressin. In the context of migraine, the findings suggest that the transmission of headache-related nociceptive signals from the thalamus to the cortex may be modulated by opposing forces (i.e., facilitatory, inhibitory that are governed by continuous adjustments needed to keep physiological, behavioral, cognitive and emotional homeostasis.

  5. Mixed models in cerebral ischemia study

    Directory of Open Access Journals (Sweden)

    Matheus Henrique Dal Molin Ribeiro

    2016-06-01

    Full Text Available The data modeling from longitudinal studies stands out in the current scientific scenario, especially in the areas of health and biological sciences, which induces a correlation between measurements for the same observed unit. Thus, the modeling of the intra-individual dependency is required through the choice of a covariance structure that is able to receive and accommodate the sample variability. However, the lack of methodology for correlated data analysis may result in an increased occurrence of type I or type II errors and underestimate/overestimate the standard errors of the model estimates. In the present study, a Gaussian mixed model was adopted for the variable response latency of an experiment investigating the memory deficits in animals subjected to cerebral ischemia when treated with fish oil (FO. The model parameters estimation was based on maximum likelihood methods. Based on the restricted likelihood ratio test and information criteria, the autoregressive covariance matrix was adopted for errors. The diagnostic analyses for the model were satisfactory, since basic assumptions and results obtained corroborate with biological evidence; that is, the effectiveness of the FO treatment to alleviate the cognitive effects caused by cerebral ischemia was found.

  6. Autophagy and Liver Ischemia-Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Raffaele Cursio

    2015-01-01

    Full Text Available Liver ischemia-reperfusion (I-R injury occurs during liver resection, liver transplantation, and hemorrhagic shock. The main mode of liver cell death after warm and/or cold liver I-R is necrosis, but other modes of cell death, as apoptosis and autophagy, are also involved. Autophagy is an intracellular self-digesting pathway responsible for removal of long-lived proteins, damaged organelles, and malformed proteins during biosynthesis by lysosomes. Autophagy is found in normal and diseased liver. Although depending on the type of ischemia, warm and/or cold, the dynamic process of liver I-R results mainly in adenosine triphosphate depletion and in production of reactive oxygen species (ROS, leads to both, a local ischemic insult and an acute inflammatory-mediated reperfusion injury, and results finally in cell death. This process can induce liver dysfunction and can increase patient morbidity and mortality after liver surgery and hemorrhagic shock. Whether autophagy protects from or promotes liver injury following warm and/or cold I-R remains to be elucidated. The present review aims to summarize the current knowledge in liver I-R injury focusing on both the beneficial and the detrimental effects of liver autophagy following warm and/or cold liver I-R.

  7. Nonhuman primate models of focal cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Jingjing Fan

    2017-01-01

    Full Text Available Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested clinically. Therefore, nonhuman primates were recommended as the ideal alternatives, owing to their similarities with the human cerebrovascular system, brain metabolism, grey to white matter ratio and even their rich behavioral repertoire. The present review is a thorough summary of ten methods that establish nonhuman primate models of focal cerebral ischemia; electrocoagulation, endothelin-1-induced occlusion, microvascular clip occlusion, autologous blood clot embolization, balloon inflation, microcatheter embolization, coil embolization, surgical suture embolization, suture, and photochemical induction methods. This review addresses the advantages and disadvantages of each method, as well as precautions for each model, compared nonhuman primates with rodents, different species of nonhuman primates and different modeling methods. Finally it discusses various factors that need to be considered when modelling and the method of evaluation after modelling. These are critical for understanding their respective strengths and weaknesses and underlie the selection of the optimum model.

  8. Localization of Basal Ganglia and Thalamic Damage in Dyskinetic Cerebral Palsy.

    Science.gov (United States)

    Aravamuthan, Bhooma R; Waugh, Jeff L

    2016-01-01

    Dyskinetic cerebral palsy affects 15%-20% of patients with cerebral palsy. Basal ganglia injury is associated with dyskinetic cerebral palsy, but the patterns of injury within the basal ganglia predisposing to dyskinetic cerebral palsy are unknown, making treatment difficult. For example, deep brain stimulation of the globus pallidus interna improves dystonia in only 40% of patients with dyskinetic cerebral palsy. Basal ganglia injury heterogeneity may explain this variability. To investigate this, we conducted a qualitative systematic review of basal ganglia and thalamic damage in dyskinetic cerebral palsy. Reviews and articles primarily addressing genetic or toxic causes of cerebral palsy were excluded yielding 22 studies (304 subjects). Thirteen studies specified the involved basal ganglia nuclei (subthalamic nucleus, caudate, putamen, globus pallidus, or lentiform nuclei, comprised by the putamen and globus pallidus). Studies investigating the lentiform nuclei (without distinguishing between the putamen and globus pallidus) showed that all subjects (19 of 19) had lentiform nuclei damage. Studies simultaneously but independently investigating the putamen and globus pallidus also showed that all subjects (35 of 35) had lentiform nuclei damage (i.e., putamen or globus pallidus damage); this was followed in frequency by damage to the putamen alone (70 of 101, 69%), the subthalamic nucleus (17 of 25, 68%), the thalamus (88 of 142, 62%), the globus pallidus (7/35, 20%), and the caudate (6 of 47, 13%). Globus pallidus damage was almost always coincident with putaminal damage. Noting consistent involvement of the lentiform nuclei in dyskinetic cerebral palsy, these results could suggest two groups of patients with dyskinetic cerebral palsy: those with putamen-predominant damage and those with panlenticular damage involving both the putamen and the globus pallidus. Differentiating between these groups could help predict response to therapies such as deep brain

  9. Neurons in the thalamic reticular nucleus are selective for diverse and complex visual features

    Science.gov (United States)

    Vaingankar, Vishal; Soto-Sanchez, Cristina; Wang, Xin; Sommer, Friedrich T.; Hirsch, Judith A.

    2012-01-01

    All visual signals the cortex receives are influenced by the perigeniculate sector (PGN) of the thalamic reticular nucleus, which receives input from relay cells in the lateral geniculate and provides feedback inhibition in return. Relay cells have been studied in quantitative depth; they behave in a roughly linear fashion and have receptive fields with a stereotyped center-surround structure. We know far less about reticular neurons. Qualitative studies indicate they simply pool ascending input to generate non-selective gain control. Yet the perigeniculate is complicated; local cells are densely interconnected and fire lengthy bursts. Thus, we employed quantitative methods to explore the perigeniculate using relay cells as controls. By adapting methods of spike-triggered averaging and covariance analysis for bursts, we identified both first and second order features that build reticular receptive fields. The shapes of these spatiotemporal subunits varied widely; no stereotyped pattern emerged. Companion experiments showed that the shape of the first but not second order features could be explained by the overlap of On and Off inputs to a given cell. Moreover, we assessed the predictive power of the receptive field and how much information each component subunit conveyed. Linear-non-linear (LN) models including multiple subunits performed better than those made with just one; further each subunit encoded different visual information. Model performance for reticular cells was always lesser than for relay cells, however, indicating that reticular cells process inputs non-linearly. All told, our results suggest that the perigeniculate encodes diverse visual features to selectively modulate activity transmitted downstream. PMID:23269915

  10. Lesions of reuniens and rhomboid thalamic nuclei impair radial maze win-shift performance.

    Science.gov (United States)

    Hembrook, Jacqueline R; Mair, Robert G

    2011-08-01

    The reuniens (Re) and rhomboid (Rh) nuclei are major sources of thalamic input to hippocampus and medial prefrontal cortex. We compared effects of lesions in ReRh and other parts of the midline-intralaminar complex on tasks affected by lesions in terminal fields innervated by these nuclei, including: visuospatial reaction time (VSRT), a measure of sensory guided responding; serial VSRT, a measure of action sequence learning; and win/shift radial arm maze (RAM) measures of spatial memory. ReRh lesions affected RAM, but not VSRT or serial VSRT performance. The effects of caudal intralaminar lesions were doubly dissociated from ReRh lesions, affecting VSRT, but not RAM or serial VSRT performance. Rostral intralaminar lesions did not produce significant impairments, other than a subgroup with larger lesions that were impaired performing a delayed RAM task. Combined lesions damaging all three sites produced RAM deficits comparable to ReRh lesions and VSRT deficits comparable to caudal intralaminar lesions. Thus there was no indication that deficits produced by lesions in one site were exacerbated significantly by the cumulative effect of damage in other parts of the midline-intralaminar complex. The effects of ReRh lesions provide evidence that these nuclei affect memory functions of hippocampus and medial prefrontal cortex. The double dissociation observed between the effects of ReRh and caudal intralaminar nuclei provides evidence that different nuclei within the midline-intralaminar complex affect distinct aspects of cognition consistent with the effects of lesions in the terminal fields they innervate. Copyright © 2010 Wiley-Liss, Inc.

  11. Thalamic deep brain stimulation for neuropathic pain after amputation or brachial plexus avulsion.

    Science.gov (United States)

    Pereira, Erlick A C; Boccard, Sandra G; Linhares, Paulo; Chamadoira, Clara; Rosas, Maria José; Abreu, Pedro; Rebelo, Virgínia; Vaz, Rui; Aziz, Tipu Z

    2013-09-01

    Fifteen hundred patients have received deep brain stimulation (DBS) to treat neuropathic pain refractory to pharmacotherapy over the last half-century, but few during the last decade. Deep brain stimulation for neuropathic pain has shown variable outcomes and gained consensus approval in Europe but not the US. This study prospectively evaluated the efficacy at 1 year of DBS for phantom limb pain after amputation, and deafferentation pain after brachial plexus avulsion (BPA), in a single-center case series. Patient-reported outcome measures were collated before and after surgery, using a visual analog scale (VAS) score, 36-Item Short-Form Health Survey (SF-36), Brief Pain Inventory (BPI), and University of Washington Neuropathic Pain Score (UWNPS). Twelve patients were treated over 29 months, receiving contralateral, ventroposterolateral sensory thalamic DBS. Five patients were amputees and 7 had BPAs, all from traumas. A postoperative trial of externalized DBS failed in 1 patient with BPA. Eleven patients proceeded to implantation and gained improvement in pain scores at 12 months. No surgical complications or stimulation side effects were noted. In the amputation group, after 12 months the mean VAS score improved by 90.0% ± 10.0% (p = 0.001), SF-36 by 57.5% ± 97.9% (p = 0.127), UWNPS by 80.4% ± 12.7% (p stimulation demonstrated efficacy at 1 year for chronic neuropathic pain after traumatic amputation and BPA. Clinical trials that retain patients in long-term follow-up are desirable to confirm findings from prospectively assessed case series.

  12. Deep Brain Stimulation of the Dentato-Rubro-Thalamic Tract: Outcomes of Direct Targeting for Tremor.

    Science.gov (United States)

    Fenoy, Albert J; Schiess, Mya C

    2017-07-01

    Targeting the dentato-rubro-thalamic tract (DRTt) has been suggested to be efficacious in deep brain stimulation (DBS) for tremor suppression, both in case reports and post-hoc analyses. This prospective observational study sought to analyze outcomes after directly targeting the DRTt in tremor patients. 20 consecutively enrolled intention tremor patients obtained pre-operative MRI with diffusion tensor (dTi) sequences. Mean baseline tremor amplitude based on The Essential Tremor Rating Assessment Scale was recorded. The DRTt was drawn for each individual on StealthViz software (Medtronic) using the dentate nucleus as the seed region and the ipsilateral pre-central gyrus as the end region and then directly targeted during surgery. Intraoperative testing confirmed successful tremor control. Post-operative analysis of electrode position relative to the DRTt was performed, as was post-operative assessment of tremor improvement. The mean age of patients was 66.8 years; mean duration of tremor was 16 years. Mean voltage for the L electrode = 3.4 V; R = 2.6 V. Mean distance from the center of the active electrode contact to the DRTt was 0.9 mm on the L, and 0.8 mm on the R. Improvement in arm tremor amplitude from baseline after DBS was significant (P tremor suppression. Accounting for hardware, software, and model limitations, depiction of the DRTt allows for placement of electrode contacts directly within the fiber tract for modulation despite any anatomical variation, which reproducibly resulted in good tremor control. © 2017 International Neuromodulation Society.

  13. Chronological changes in the CT appearance of experimental radiofrequency thalamic lesions in dogs

    International Nuclear Information System (INIS)

    Ebisutani, Daizo; Makino, Akira; Matsumoto, Keizo; Ii, Kunio

    1987-01-01

    The location and extent of thalamic lesions following thalamotomy have been determined by the monopolar radiofrequency method. They can sometimes be identified in CT images as low-density areas, but also exceptionally high-density areas. However, this low-density area changes with time from a larger one in the acute stage to a smaller spot in the chronic stage, and sometimes it disappears within three months after the operation. It is the purpose of this study to elucidate the proper timing for the scanning for the anatomical mapping of the lesion in chronologically varying images of the lesions. Stereotactic experimental radiofrequency lesions were created in the thalamus of 35 mongrel dogs at 70 deg C for 120 sec. CT images of the brain were obtained at Days 0, 3, 7, 10, 14, 21 and 60. The lesions of the specimens and CT images tended to grow from Day 0 to Day 3, and then to grow smaller to Day 60. The area of the thalamus was measured in each specimen by means of coronal cutting. The thalamus of the lesion side was swollen from Day 0 to Day 10, but it became almost equal to that of the non-lesion side between Day 14 and Day 21. Then, the thalamus of the lesion side became atrophic. The mass effects with a ventricular deformity and a midline shift on CT images were diminished at Day 14 in most cases. The lesion areas at Day 14 corresponded to the contrast-enhanced area more than to that of the plain CT histologically. These results suggest that a lesion demonstrated by CE-CT scans at Day 14 would be suitable for anatomical mapping. (author)

  14. Thalamic Deep Brain Stimulation for Essential Tremor Also Reduces Voice Tremor.

    Science.gov (United States)

    Kundu, Bornali; Schrock, Lauren; Davis, Tyler; House, Paul A

    2017-12-12

    Voice tremor is a common feature of essential tremor (ET) that is difficult to treat medically and significantly affects quality of life. Deep brain stimulation (DBS) of the ventral intermediate nucleus (Vim) of the thalamus is effective in improving contralateral distal limb tremor and has been shown in limited studies to affect voice tremor. Our objective was to retrospectively evaluate whether Vim-DBS used to treat patients with essential motor tremor also effectively treated underlying concurrent voice tremor and assess whether particular lead locations were favorable for treating vocal tremor. In this retrospective cohort study, patients had unilateral or bilateral lead placement and were monitored for up to 12 months. We used the Fahn-Tolosa-Marin (FTM) subscore to assess vocal tremor. Changes in vocal tremor before and after stimulation and over several sessions were assessed. Of the 77 patients who met the inclusion criteria and were treated for essential tremor, 20 (26%) patients had vocal tremor prior to stimulation. Active Vim-DBS decreased the amplitude of voice tremor by 80% (p centroid of stimulation showed that Vim thalamic stimulation that is more anterior on average yielded better voice tremor control, significantly so on the left side (p < 0.05). Additionally, there was improvement in head, tongue, and face tremor scores (p < 0.05). Unilateral and bilateral Vim-DBS targeted to treat the motor component of essential tremor also dramatically decreased the amplitude of voice tremor in this group of patients, suggesting a potential benefit of this treatment for affected patients. © 2017 International Neuromodulation Society.

  15. Active action potential propagation but not initiation in thalamic interneuron dendrites

    Science.gov (United States)

    Casale, Amanda E.; McCormick, David A.

    2012-01-01

    Inhibitory interneurons of the dorsal lateral geniculate nucleus of the thalamus modulate the activity of thalamocortical cells in response to excitatory input through the release of inhibitory neurotransmitter from both axons and dendrites. The exact mechanisms by which release can occur from dendrites are, however, not well understood. Recent experiments using calcium imaging have suggested that Na/K based action potentials can evoke calcium transients in dendrites via local active conductances, making the back-propagating action potential a candidate for dendritic neurotransmitter release. In this study, we employed high temporal and spatial resolution voltage-sensitive dye imaging to assess the characteristics of dendritic voltage deflections in response to Na/K action potentials in interneurons of the mouse dorsal lateral geniculate nucleus. We found that trains or single action potentials elicited by somatic current injection or local synaptic stimulation led to action potentials that rapidly and actively back-propagated throughout the entire dendritic arbor and into the fine filiform dendritic appendages known to release GABAergic vesicles. Action potentials always appeared first in the soma or proximal dendrite in response to somatic current injection or local synaptic stimulation, and the rapid back-propagation into the dendritic arbor depended upon voltage-gated sodium and TEA-sensitive potassium channels. Our results indicate that thalamic interneuron dendrites integrate synaptic inputs that initiate action potentials, most likely in the axon initial segment, that then back-propagate with high-fidelity into the dendrites, resulting in a nearly synchronous release of GABA from both axonal and dendritic compartments. PMID:22171033

  16. Distonia virtual por infarto talâmico posterolateral ventral: relato de caso Virtual dystonia due to a posteroventrolateral thalamic infarct: case report

    Directory of Open Access Journals (Sweden)

    Ricardo De Oliveira-Souza

    1996-09-01

    dystonia not outwardly expressed through the motor system. There was severe proprioceptive loss in the same toes that harbored the cramp. MRI showed the appropriate lesion in the posteroventrolateral thalamus (VPL and wallerian degeneration of thalamo-cortical projections. SPECT showed hypoperfusion of the overlying ipsilateral parietal cortex as well as of the basal nuclei bilaterally, besides the expected image of thalamic exclusion. We hypothesize that the infarct disconnected the somatic sensory cortex (S-I from critical proprioceptive input with relative sparing of superficial sensibility. Lifting the foot deprived S-I of tonic inputs conveyed by undamaged contact-pressure pathways, a functional effect promptly reversed by placing the foot back against the ground. The case illustrates how a capricious deafferentation of S-I by a discrete VPL thalamic infarct might facilitate the emergence of autochthonous activity in the primary somesthetic cortex and give rise to a purely mental abnormal involuntary movement akin to the unimodal hallucinoses of which the syndrome of Bonnet is the best-known example. Virtual abnormal involuntary movements may be concealed more often than appreciated by complaints such as pains or cramps in patients with nervous system lesions.

  17. Low thalamic NAA-concentration corresponds to strong neural activation in working memory in Kleine-Levin syndrome.

    Science.gov (United States)

    Vigren, Patrick; Tisell, Anders; Engström, Maria; Karlsson, Thomas; Leinhard Dahlqvist, Olof; Lundberg, Peter; Landtblom, Anne-Marie

    2013-01-01

    Kleine Levin Syndrome (KLS) is a rare disorder of periodic hypersomnia and behavioural disturbances in young individuals. It has previously been shown to be associated with disturbances of working memory (WM), which, in turn, was associated with higher activation of the thalamus with increasing WM load, demonstrated with functional magnetic resonance imaging (fMRI). In this study we aimed to further elucidate how these findings are related to the metabolism of the thalamus. fMRI and magnetic resonance spectroscopy were applied while performing a WM task. Standard metabolites were examined: n-acetylaspartate (NAA), myo-inositol, choline, creatine and glutamate-glutamine. Fourteen KLS-patients and 15 healthy controls participated in the study. The patients with active disease were examined in asymptomatic periods. There was a statistically significant negative correlation between thalamic fMRI-activation and thalamic NAA, i.e., high fMRI-activation corresponded to low NAA-levels. This correlation was not seen in healthy controls. Thalamic levels of NAA in patients and controls showed no significant differences between the groups. None of the other metabolites showed any co-variation with fMRI-activation. This study shows negative correlation between NAA-levels and fMRI-activity in the left thalamus of KLS-patients while performing a WM task. This correlation could not be found in healthy control subjects, primarily interpreted as an effect of increased effort in the patient group upon performing the task. It might indicate a disturbance in the neuronal networks responsible for WM in KLS patients, resulting in higher effort at lower WM load, compared with healthy subjects. The general relationship between NAA and BOLD-signal is also discussed in the article.

  18. Two distinct populations of projection neurons in the rat lateral parafascicular thalamic nucleus and their cholinergic responsiveness.

    Science.gov (United States)

    Beatty, J A; Sylwestrak, E L; Cox, C L

    2009-08-04

    The lateral parafascicular nucleus (lPf) is a member of the intralaminar thalamic nuclei, a collection of nuclei that characteristically provides widespread projections to the neocortex and basal ganglia and is associated with arousal, sensory, and motor functions. Recently, lPf neurons have been shown to possess different characteristics than other cortical-projecting thalamic relay neurons. We performed whole cell recordings from lPf neurons using an in vitro rat slice preparation and found two distinct neuronal subtypes that were differentiated by distinct morphological and physiological characteristics: diffuse and bushy. Diffuse neurons, which had been previously described, were the predominant neuronal subtype (66%). These neurons had few, poorly-branching, extended dendrites, and rarely displayed burst-like action potential discharge, a ubiquitous feature of thalamocortical relay neurons. Interestingly, we discovered a smaller population of bushy neurons (34%) that shared similar morphological and physiological characteristics with thalamocortical relay neurons of primary sensory thalamic nuclei. In contrast to other thalamocortical relay neurons, activation of muscarinic cholinergic receptors produced a membrane hyperpolarization via activation of M(2) receptors in most lPf neurons (60%). In a minority of lPf neurons (33%), muscarinic agonists produced a membrane depolarization via activation of predominantly M(3) receptors. The muscarinic receptor-mediated actions were independent of lPf neuronal subtype (i.e. diffuse or bushy neurons); however the cholinergic actions were correlated with lPf neurons with different efferent targets. Retrogradely-labeled lPf neurons from frontal cortical fluorescent bead injections primarily consisted of bushy type lPf neurons (78%), but more importantly, all of these neurons were depolarized by muscarinic agonists. On the other hand, lPf neurons labeled by striatal injections were predominantly hyperpolarized by muscarinic

  19. Visuomotor signals for reaching movements in the rostro-dorsal sector of the monkey thalamic reticular nucleus.

    Science.gov (United States)

    Saga, Yosuke; Nakayama, Yoshihisa; Inoue, Ken-Ichi; Yamagata, Tomoko; Hashimoto, Masashi; Tremblay, Léon; Takada, Masahiko; Hoshi, Eiji

    2017-05-01

    The thalamic reticular nucleus (TRN) collects inputs from the cerebral cortex and thalamus and, in turn, sends inhibitory outputs to the thalamic relay nuclei. This unique connectivity suggests that the TRN plays a pivotal role in regulating information flow through the thalamus. Here, we analyzed the roles of TRN neurons in visually guided reaching movements. We first used retrograde transneuronal labeling with rabies virus, and showed that the rostro-dorsal sector of the TRN (TRNrd) projected disynaptically to the ventral premotor cortex (PMv). In other experiments, we recorded neurons from the TRNrd or PMv while monkeys performed a visuomotor task. We found that neurons in the TRNrd and PMv showed visual-, set-, and movement-related activity modulation. These results indicate that the TRNrd, as well as the PMv, is involved in the reception of visual signals and in the preparation and execution of reaching movements. The fraction of neurons that were non-selective for the location of visual signals or the direction of reaching movements was greater in the TRNrd than in the PMv. Furthermore, the fraction of neurons whose activity increased from the baseline was greater in the TRNrd than in the PMv. The timing of activity modulation of visual-related and movement-related neurons was similar in TRNrd and PMv neurons. Overall, our data suggest that TRNrd neurons provide motor thalamic nuclei with inhibitory inputs that are predominantly devoid of spatial selectivity, and that these signals modulate how these nuclei engage in both sensory processing and motor output during visually guided reaching behavior. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  20. Connectivity-based parcellation of the thalamus explains specific cognitive and behavioural symptoms in patients with bilateral thalamic infarct.

    Directory of Open Access Journals (Sweden)

    Laura Serra

    Full Text Available A novel approach based on diffusion tractography was used here to characterise the cortico-thalamic connectivity in two patients, both presenting with an isolated bilateral infarct in the thalamus, but exhibiting partially different cognitive and behavioural profiles. Both patients (G.P. and R.F. had a pervasive deficit in episodic memory, but only one of them (R.F. suffered also from a dysexecutive syndrome. Both patients had an MRI scan at 3T, including a T1-weighted volume. Their lesions were manually segmented. T1-volumes were normalised to standard space, and the same transformations were applied to the lesion masks. Nineteen healthy controls underwent a diffusion-tensor imaging (DTI scan. Their DTI data were normalised to standard space and averaged. An atlas of Brodmann areas was used to parcellate the prefrontal cortex. Probabilistic tractography was used to assess the probability of connection between each voxel of the thalamus and a set of prefrontal areas. The resulting map of corticothalamic connections was superimposed onto the patients' lesion masks, to assess whether the location of the thalamic lesions in R.F. (but not in G. P. implied connections with prefrontal areas involved in dysexecutive syndromes. In G.P., the lesion fell within areas of the thalamus poorly connected with prefrontal areas, showing only a modest probability of connection with the anterior cingulate cortex (ACC. Conversely, R.F.'s lesion fell within thalamic areas extensively connected with the ACC bilaterally, with the right dorsolateral prefrontal cortex, and with the left supplementary motor area. Despite a similar, bilateral involvement of the thalamus, the use of connectivity-based segmentation clarified that R.F.'s lesions only were located within nuclei highly connected with the prefrontal cortical areas, thus explaining the patient's frontal syndrome. This study confirms that DTI tractography is a useful tool to examine in vivo the effect of focal

  1. Prognosis of thalamic hemorrhage with special reference to the level of consciousness and CT findings on admission

    International Nuclear Information System (INIS)

    Yamamoto, Toshimasa; Tanahashi, Norio; Nara, Masaharu; Takenaka, Nobuo

    1991-01-01

    The prognosis of thalamic hemorrhage was studied on the basis of neurological gradings on admission, mode of extension and hematoma size on brain CT. The subjects were 126 patients with thalamic hemorrhage who were admitted to Ashikaga Red Cross Hospital during the past ten years. Among the subjects, 120 patients (ages 64±10 yr; mean ±SD) were treated with conservative therapy, and 6 patients (ages 59±10 yr) with surgical therapy (ventricular drainage). Brain CT scans were done within 48 hours after onset in all patients. Neurological gradings, brain CT classification and prognosis were investigated according to the criteria of the Japanese Conference on Surgery for Cerebral Stroke. The results of conservative therapy were as follows: (1) In the grade I group on the neurological gradings, 29 of the 39 patients (74%) recovered to full work or an independent life, and none of them died. In the grade IV and V groups, mortality rate was 86%. (2) The prognosis was more unfavorable in type III than in types I and II on the CT classification. Twenty-six of the 36 patients (73%) with type I-a recovered to full work or an independent life. Twenty-five of the 34 patients (74%) with the type III-b died. (3) Only 4 of the 75 patients (5%) with less than 10 ml of hematoma volume died. In contrast, all 14 patients with more than 25 ml of hematoma volume died. (4) The mortality rate among patients with ventricular rupture (47%) was significantly higher than that among patients without ventricular rupture (2%) (p<0.001). (5) The mortality rate of patients with acute hydrocephalus (83%) was significantly higher than that of patients without acute hydrocephalus (20%) (p<0.001). From the above results, it is suggested that neurological grading, brain CT classification, hematoma volume, ventricular rupture and acute hydrocephalus are important prognostic factors for thalamic hemorrhage. (author)

  2. Reversible flowchart languages and the structured reversible program theorem

    DEFF Research Database (Denmark)

    Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

    2008-01-01

    Many irreversible computation models have reversible counterparts, but these are poorly understood at present. We introduce reversible flowcharts with an assertion operator and show that any reversible flowchart can be simulated by a structured reversible flowchart using only three control flow...... operators. Reversible flowcharts are r- Turing-complete, meaning that they can simuluate reversible Turing machines without garbage data. We also demonstrate the injectivization of classical flowcharts into reversible flowcharts. The reversible flowchart computation model provides a theoretical...

  3. Electrocardiographically and symptomatically silent myocardial ischemia during exercise testing

    International Nuclear Information System (INIS)

    Kurata, Chinori; Tawarahara, Kei; Sakata, Kazuyuki; Taguchi, Takahisa; Fukumoto, Yoshihiro; Kobayashi, Akira; Yamazaki, Noboru; Tanaka, Hiroshi

    1991-01-01

    Certain patients with coronary artery disease (CAD) may have neither ST depression nor chest pain during exercise despite the presence of myocardial ischemia. The frequency and characteristics of such electrocardiographically and symptomatically silent ischemia were studied in 171 patients with both angiographically documented CAD and scintigraphically documented ischemia. Fifty-six (33%) of 171 patients had neither ST depression nor chest pain (Group N), and 115 (67%) had ST depression and/or chest pain (Group P). The two groups were similar with respect to age, gender, the prevalence of prior infarction, and peak systolic blood pressure. Group N patients, however, had a higher mean peak heart rate and rate-pressure product, less severe scintigraphic ischemia, a lower lung thallium-201 uptake, and a smaller number of diseased vessels. Stepwise discriminant analysis showed a history of effort angina, lung thallium-201 uptake, and scintigraphic severity of ischemia to be significant discriminators between Groups N and P. In conclusion, electrocardiographically and symptomatically silent ischemia may be common during exercise in patients with CAD, and less severe ischemia may be one of important determinants. (author)

  4. Analysis of correlation between white matter changes and functional responses in thalamic stroke: a DTI & EEG study.

    Science.gov (United States)

    Duru, Adil Deniz; Duru, Dilek Göksel; Yumerhodzha, Sami; Bebek, Nerses

    2016-06-01

    Diffusion tensor imaging (DTI) allows in vivo structural brain mapping and detection of microstructural disruption of white matter (WM). One of the commonly used parameters for grading the anisotropic diffusivity in WM is fractional anisotropy (FA). FA value helps to quantify the directionality of the local tract bundle. Therefore, FA images are being used in voxelwise statistical analyses (VSA). The present study used Tract-Based Spatial Statistics (TBSS) of FA images across subjects, and computes the mean skeleton map to detect voxelwise knowledge of the tracts yielding to groupwise comparison. The skeleton image illustrates WM structure and shows any changes caused by brain damage. The microstructure of WM in thalamic stroke is investigated, and the VSA results of healthy control and thalamic stroke patients are reported. It has been shown that several skeleton regions were affected subject to the presence of thalamic stroke (FWE, p EEG (qEEG) scores and neurophysiological tests with the FA skeleton for the entire test group is also investigated. We compared measurements that are related to the same fibers across subjects, and discussed implications for VSA of WM in thalamic stroke cases, for the relationship between behavioral tests and FA skeletons, and for the correlation between the FA maps and qEEG scores.Results obtained through the regression analyses did not exceed the corrected statistical threshold values for multiple comparisons (uncorrected, p EEG, cingulum bundle and corpus callosum were found to be related. These areas are parts of the Default Mode Network (DMN) where DMN is known to be involved in resting state EEG theta activity. The relation between the EEG alpha band power values and FA values of the skeleton was found to support the cortico-thalamocortical cycles for both subject groups. Further, the neurophysiological tests including Benton Face Recognition (BFR), Digit Span test (DST), Warrington Topographic Memory test (WTMT

  5. Tc-99m ECD brain SPECT in patients with traumatic brain injury: evaluating distribution of hypoperfusion and assessment of cognitive and behavioral impairment in relation to thalamic hypoperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soon Ah; Lim, Seok Tae; Sohn, Myung Hee [College of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

    2000-12-01

    We evaluated the distribution of hypoperfusion in patients with traumatic brain injury (TBI) and the relationship of thalamic hypoperfusion to severity of cognitive and behavioral sequelae. Tc-99m ECD SPECT and MRI were performed in 103 patients (M/F=81/22, mean age 34.7{+-} 15.4 yrs) from 0.5 to 55 months (mean 10.3 months) after TBI. The patients were divided into three groups showing no abnormalities (G1), focal (G2) and diffuse injury (G3) on MRI. Psychometric tests assessed 11 cognitive or behavioral items. In all patients, we evaluated the distribution of hypoperfused areas in SPECT, and in 57/103 patients, neuropsychological (NP) abnormalities in patients with thalamic hypoperfusion were compared with those of patients without thalamic hypoperfusion. The perfusion dificits were most frequently located in the frontal lobe (G1, 42.3%: G2 34.5%: G3 33.3%), temporal lobe (24{approx}26%) thalami (21{approx}22.4%), parietal and occipital lobe ({<=}10%). Numbers of NP abnormalities in the cases of cortical hypoperfusion with or without concomitant thalamic hypoperfusion were following: the former 4.7{+-}1.5 and the latter 3.2{+-}1.4 in G1, 5.0{+-}1.1 and 4.8{+-}1.2 in G2, 6.8{+-}1.8 and 6.3{+-}1.1 in G3, respectively. This difference according to thalamic hypoperfusion was significant in G1 (p=0.002), but was not significant in G2 or G3. SPECT in patients with TBI had demonstrated hypoperfusion mostly involving the frontal, temporal and thalami. In normal group on MRI, frontal hypoperfusion was more prominent than that of any other group, Furthermore in this group, SPECT could predict severity of NP outcome by concomitant thalamic hypoperfusion with cerebral cortical abnormalities.

  6. Tc-99m ECD brain SPECT in patients with traumatic brain injury: evaluating distribution of hypoperfusion and assessment of cognitive and behavioral impairment in relation to thalamic hypoperfusion

    International Nuclear Information System (INIS)

    Park, Soon Ah; Lim, Seok Tae; Sohn, Myung Hee

    2000-01-01

    We evaluated the distribution of hypoperfusion in patients with traumatic brain injury (TBI) and the relationship of thalamic hypoperfusion to severity of cognitive and behavioral sequelae. Tc-99m ECD SPECT and MRI were performed in 103 patients (M/F=81/22, mean age 34.7± 15.4 yrs) from 0.5 to 55 months (mean 10.3 months) after TBI. The patients were divided into three groups showing no abnormalities (G1), focal (G2) and diffuse injury (G3) on MRI. Psychometric tests assessed 11 cognitive or behavioral items. In all patients, we evaluated the distribution of hypoperfused areas in SPECT, and in 57/103 patients, neuropsychological (NP) abnormalities in patients with thalamic hypoperfusion were compared with those of patients without thalamic hypoperfusion. The perfusion dificits were most frequently located in the frontal lobe (G1, 42.3%: G2 34.5%: G3 33.3%), temporal lobe (24∼26%) thalami (21∼22.4%), parietal and occipital lobe (≤10%). Numbers of NP abnormalities in the cases of cortical hypoperfusion with or without concomitant thalamic hypoperfusion were following: the former 4.7±1.5 and the latter 3.2±1.4 in G1, 5.0±1.1 and 4.8±1.2 in G2, 6.8±1.8 and 6.3±1.1 in G3, respectively. This difference according to thalamic hypoperfusion was significant in G1 (p=0.002), but was not significant in G2 or G3. SPECT in patients with TBI had demonstrated hypoperfusion mostly involving the frontal, temporal and thalami. In normal group on MRI, frontal hypoperfusion was more prominent than that of any other group, Furthermore in this group, SPECT could predict severity of NP outcome by concomitant thalamic hypoperfusion with cerebral cortical abnormalities

  7. Review on herbal medicine on brain ischemia and reperfusion

    Directory of Open Access Journals (Sweden)

    Nahid Jivad

    2015-10-01

    Cerebral ischemia and reperfusion is known to induce the generation of reactive oxygen species that can lead to oxidative damage of proteins, membrane lipids and nucleic acids. A decrease in tissue antioxidant capacity, an increase in lipid peroxidation as well as an increase in lipid peroxidation inhibitors have been demonstrated in several models of brain ischemia. This paper reviews the number of commonly used types of herbal medicines effective for the treatment of stroke. The aim of this paper was to review evidences from controlled studies in order to discuss whether herbal medicine can be helpful in the treatment of brain ischemia and reperfusion.

  8. Exertional headache and coronary ischemia despite normal electrocardiographic stress testing.

    Science.gov (United States)

    Cutrer, F Michael; Huerter, Karina

    2006-01-01

    Exertional headaches may under certain conditions reflect coronary ischemia. We report the case of a patient seen in a neurology referral practice whose exertional headaches, even in the face of two normal electrocardiographic stress tests and in the absence of underlying chest pain were the sole symptoms of coronary ischemia as detected by Tc-99m Sestamibi testing SPECT stress testing. Stent placement resulted in complete resolution of headaches. Exertional headache in the absence of chest pain may reflect underlying symptomatic coronary artery disease (CAD) even when conventional electrocardiographic stress testing does not indicate ischemia.

  9. Electrocardiographic markers of ischemia during mental stress testing in postinfarction patients. Role of body surface mapping

    International Nuclear Information System (INIS)

    Bosimini, E.; Galli, M.; Guagliumi, G.; Giubbini, R.; Tavazzi, L.

    1991-01-01

    In patients with coronary artery disease, radionuclide investigations have documented a high incidence of mental stress-induced myocardial ischemia in the absence of significant electrocardiographic changes and/or angina. To investigate the causes of the low electrocardiographic sensitivity, we recorded body surface maps during mental arithmetic in 22 normal volunteers and 37 postinfarction patients with residual exercise ischemia. Myocardial perfusion was studied with thallium-201 or technetium-99 (SESTAMIBI) planar scans. In 14 patients, body surface maps were also recorded during atrial pacing at the heart rate values achieved during mental stress. While taking the body surface maps, the area from J point to 80 msec after this point (ST-80) was analyzed by integral maps, difference maps, and departure maps. The body surface mapping criteria for ischemia were a new negative area on the integral maps, a negative potential of more than 2 SD from mean normal values on the difference maps, and a negative departure index of more than 2. Scintigraphy showed asymptomatic myocardial hypoperfusion in 33 patients. Eight patients had significant ST segment depression. The ST-80 integral and difference maps identified 17 ischemic patients. Twenty-four patients presented abnormal departure maps. One patient presented ST depression and abnormal body surface maps without reversible tracer defect. In 14 of 14 patients, atrial pacing did not reproduce the body surface map abnormalities. The analyses of the other electrocardiographic variables showed that in patients with mental stress-induced perfusion defects, only changes of T apex-T offset (aT-eT) interval in Frank leads and changes of maximum negative potential value of aT-eT integral maps significantly differed from those of normal subjects

  10. Tissue inhibitor of matrix metalloproteinase-1 mediates erythropoietin-induced neuroprotection in hypoxia ischemia.

    Science.gov (United States)

    Souvenir, Rhonda; Fathali, Nancy; Ostrowski, Robert P; Lekic, Tim; Zhang, John H; Tang, Jiping

    2011-10-01

    Previous studies have shown that erythropoietin (EPO) is neuroprotective in both in vivo and in vitro models of hypoxia ischemia. However these studies hold limited clinical translations because the underlying mechanism remains unclear and the key molecules involved in EPO-induced neuroprotection are still to be determined. This study investigated if tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and its upstream regulator signaling molecule Janus kinase-2 (JAK-2) are critical in EPO-induced neuroprotection. Hypoxia ischemia (HI) was modeled in-vitro by oxygen and glucose deprivation (OGD) and in-vivo by a modified version of Rice-Vannucci model of HI in 10-day-old rat pups. EPO treated cells were exposed to AG490, an inhibitor of JAK-2 or TIMP-1 neutralizing antibody for 2h with OGD. Cell death, phosphorylation of JAK-2 and signal transducers and activators of transcription protein-3 (STAT-3), TIMP-1 expression, and matrix metalloproteinase-9 (MMP-9) activity were measured and compared with normoxic group. Hypoxic ischemic animals were treated one hour following HI and evaluated 48 h after. Our data showed that EPO significantly increased cell survival, associated with increased TIMP-1 activity, phosphorylation of JAK-2 and STAT-3, and decreased MMP-9 activity in vivo and in vitro. EPO's protective effects were reversed by inhibition of JAK-2 or TIMP-1 in both models. We concluded that JAK-2, STAT-3 and TIMP-1 are key mediators of EPO-induced neuroprotection during hypoxia ischemia injury. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. [Identification of early irreversible damage area in a rat model of cerebral ischemia and reperfusion].

    Science.gov (United States)

    Liu, S; Guo, Y

    2000-02-01

    To observe the early neuron ischemic damage in focal cerebral ischemia/reperfusion with histostaining methods of argyrophil III (AG III), Toludine blue(TB), and H&E, and to make out the 'separating line' between the areas of reversible and irreversible early ischemic damage. Forty-two male Wistar rats were randomly divided into the following groups: pseudo-surgical, blank-control, O2R0(occluded for 2 hours and reperfused for 0 hour), O2R0.5, O2R2, O2R4, O2R24. There were 6 rats in each group. Rats in experimental groups were suffered focal cerebral ischemia/reperfusion through a nylon suture method. After a special processor for tissue manage, the brain were coronal sectioned and stained with H&E, TB, and AG III. The area where dark neurons dwell in (ischemic core) were calculated with image analysis system. The success rate of ischemic model for this experiment is 90%. After being stained with argyrophil III method, normal neurons appear yellow or pale brown, which is hardly distinguished from the pale brown background. The ischemic neuron stained black, and has collapsed body and "corkscrew-like" axon or dentries, which were broken to some extent. The neuropil in the dark neurons dwelt area appears gray or pale black, which is apparently different from the pale brown neighborhood area. The distribution of dark neurons in cortex varies according to different layers, and has a character of columnar form. The dark neurons present as early as 2 hours ischemia without reperfusion with AG III method. AG III stain could selectively display early ischemic neurons, the area dwelt by dark neurons represent early ischemic core. Dark neuron is possibly the irreversibly damaged neuron. Identification of dark neurons could be helpful in the discrimination between early ischemic center and penumbra.

  12. Myocardial fatty acid utilisation during exercise induced ischemia in patients with coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, K.S. [First Dept. of Medicine, Helsinki Univ. Central Hospital (Finland); Nikkinen, P. [Dept. of Clinical Chemistry, Helsinki Univ. Central Hospital (Finland); Lindroth, L. [Medix Diacor Lab. Services, Ltd., Espoo (Finland); Kuikka, J.T. [Dept. of Clinical Physiology and Nuclear Medicine, Kuopio Univ. Hospital, Univ. of Kuopio and Niuvanniemi Hospital, Kuopio (Finland)

    2002-06-01

    Aim: Reversible or irreversible myocardial damage due to ischemia correlates with altered membrane functions of the cells. To compare myocardial free fatty acid (FFA) metabolism and flow during exercise induced ischemia we studied ten patients with coronary artery disease but without previous myocardial infarction. Methods: A series of post-exercise single-photon emission computed tomography (SPECT) measurements was performed after injection of {sup 123}I labelled heptadecanoic acid (HDA). Myocardial perfusion was estimated from the separately performed exercise-redistribution thallium study. Fatty acid metabolic rate, thallium uptake and washout were calculated for anterior, lateral, posterior and septal segments. Results: The more reduced post-exercise FFA metabolic rate (-63{+-}18%, mean {+-}1 SD) compared to flow (-36{+-}16%) was related to the severity of myocardial ischemia and wall motion abnormalities. Conclusion: In this small group of patients, the reduced post-exercise FFA metabolic rate tentatively suggests a parsimonious workload of the exercising myocardium by reducing oxygen consumption in patients with coronary artery disease. (orig.) [German] Ziel: Bei reversibler und irreversibler Myokardschaedigung infolge Ischaemie sind die Membranfunktionen der Zellen veraendert. Um myokardialen Metabolismus freier Fettsaeuren (FFA) und Durchblutung bei belastungsinduzierter Ischaemie zu vergleichen, untersuchten wir zehn Patienten mit Koronarinsuffizienz, aber ohne vorangegangenen Myokardinfarkt. Methoden: Nach Injektion von {sup 123}I-markierter Heptadekansaeure (HDA) wurde eine Serie von SPECT-Messungen nach Belastung aufgenommen. Die myokardiale Perfusion wurde abgeschaetzt durch die separat durchgefuehrte Thalliumverteilungsstudie nach Belastung. Fettsaeurestoffwechsel, Thallium-Uptake und -Washout wurden fuer die anterioren, posterioren und septalen Segmente berechnet. Ergebnisse: Eine eingeschraenktere FFA-Stoffwechselrate (-63{+-}18%, {+-}1 SD

  13. Mitochondrial events responsible for morphine's cardioprotection against ischemia/reperfusion injury

    International Nuclear Information System (INIS)

    He, Haiyan; Huh, Jin; Wang, Huihua; Kang, Yi; Lou, Jianshi; Xu, Zhelong

    2016-01-01

    Morphine may induce cardioprotection by targeting mitochondria, but little is known about the exact mitochondrial events that mediate morphine's protection. We aimed to address the role of the mitochondrial Src tyrosine kinase in morphine's protection. Isolated rat hearts were subjected to 30 min ischemia and 2 h of reperfusion. Morphine was given before the onset of ischemia. Infarct size and troponin I release were measured to evaluate cardiac injury. Oxidative stress was evaluated by measuring mitochondrial protein carbonylation and mitochondrial ROS generation. HL-1 cells were subjected to simulated ischemia/reperfusion and LDH release and mitochondrial membrane potential (ΔΨm) were measured. Morphine reduced infarct size as well as cardiac troponin I release which were aborted by the selective Src tyrosine kinase inhibitors PP2 and Src-I1. Morphine also attenuated LDH release and prevented a loss of ΔΨm at reperfusion in a Src tyrosine kinase dependent manner in HL-1 cells. However, morphine failed to reduce LDH release in HL-1 cells transfected with Src siRNA. Morphine increased mitochondrial Src phosphorylation at reperfusion and this was abrogated by PP2. Morphine attenuated mitochondrial protein carbonylation and mitochondrial superoxide generation at reperfusion through Src tyrosine kinase. The inhibitory effect of morphine on the mitochondrial complex I activity was reversed by PP2. These data suggest that morphine induces cardioprotection by preventing mitochondrial oxidative stress through mitochondrial Src tyrosine kinase. Inhibition of mitochondrial complex I at reperfusion by Src tyrosine kinase may account for the prevention of mitochondrial oxidative stress by morphine. - Highlights: • Morphine induced mito-Src phosphorylation and reduced infarct size in rat hearts. • Morphine failed to reduce I/R-induced LDH release in Src-silencing HL-1 cells. • Morphine prevented mitochondria damage caused by I/R through Src. • Morphine reduced

  14. Carvacrol, a food-additive, provides neuroprotection on focal cerebral ischemia/reperfusion injury in mice.

    Directory of Open Access Journals (Sweden)

    Hailong Yu

    Full Text Available Carvacrol (CAR, a naturally occurring monoterpenic phenol and food additive, has been shown to have antimicrobials, antitumor, and antidepressant-like activities. A previous study demonstrated that CAR has the ability to protect liver against ischemia/reperfusion injury in rats. In this study, we investigated the protective effects of CAR on cerebral ischemia/reperfusion injury in a middle cerebral artery occlusion mouse model. We found that CAR (50 mg/kg significantly reduced infarct volume and improved neurological deficits after 75 min of ischemia and 24 h of reperfusion. This neuroprotection was in a dose-dependent manner. Post-treatment with CAR still provided protection on infarct volume when it was administered intraperitoneally at 2 h after reperfusion; however, intracerebroventricular post-treatment reduced infarct volume even when the mice were treated with CAR at 6 h after reperfusion. These findings indicated that CAR has an extended therapeutic window, but delivery strategies may affect the protective effects of CAR. Further, we found that CAR significantly decreased the level of cleaved caspase-3, a marker of apoptosis, suggesting the anti-apoptotic activity of CAR. Finally, our data indicated that CAR treatment increased the level of phosphorylated Akt and the neuroprotection of CAR was reversed by a PI3K inhibitor LY-294002, demonstrating the involvement of the PI3K/Akt pathway in the anti-apoptotic mechanisms of CAR. Due to its safety and wide use in the food industry, CAR is a promising agent to be translated into clinical trials.

  15. Effects of Hydroalcoholic Extract of Cynodon Dactylon (L. Pers. on ISchemia/Reperfusion-Induced Arrhythmias

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    A Garjani

    2008-09-01

    Full Text Available Background and purpose of the study: Probable antiarrhythmic effects of Cynodon dactylon (L. pers. (family Poaceae against ischemia/reperfusion (I/R-induced arrhythmias were investigated in isolated rat heart. Methods: The hearts were subjected to 30min regional ischemia followed by 30min reperfusion and perfused with hydroalcoholic extract of rhizome of C. dactylon (25, 50, 100 and 200µg/ml. Results: During ischemia, the extract produced marked reduction in the number, duration and incidences of ventricular tachycardia (VT at 25 and 50µg/ml (p<0.001 and p<0.01, respectively. Total number of ischemic ventricular ectopic beats (VEBs were lowered by 25-100µg/ml (p<0.001, p<0.001 and p<0.05, respectively. At the reperfusion phase, C. dactylon (25 and 50µg/ml decreased incidence of VT from 100% (control to 13 and 33% (p<0.001 and p<0.05 respectively. Duration and number of VT and total VF incidence were also reduced at the same concentration (p<0.05 for all. Perfusion of the extract (25-100µg/ml was markedly lowered reversible VF duration from 218±99sec to 0 sec, 0 sec and 10±5sec (p<0.01, p<0.01 and p<0.05 respectively. Moreover, C. dactylon (25 and 50µg/ml decreased number of total VEBs from 349±73 to 35±17 (p<0.001 and 66±26 (p<0.01. In this study, it was also shown that perfusion of the extract produced a marked and concentration-dependent positive inotropic effect. Conclusion: The findings of this study indicate that C. dactylon produce protective effects against I/R-induced arrhythmias in isolated rat hearts probably by increase in the myocardial contractility and as a result by improvement of hemodynamic factors.

  16. Mitochondrial events responsible for morphine's cardioprotection against ischemia/reperfusion injury

    Energy Technology Data Exchange (ETDEWEB)

    He, Haiyan [Department of Physiology & Pathophysiology, Tianjin Medical University, Tianjin 300070 (China); Department of Pharmacology, Tianjin Medical University, Tianjin 300070 (China); Huh, Jin [Department of Anesthesia and Pain Medicine, Medical College, Kangwon National University, Chuncheon City (Korea, Republic of); Wang, Huihua [Department of Anesthesiology, The Second Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province (China); Kang, Yi; Lou, Jianshi [Department of Pharmacology, Tianjin Medical University, Tianjin 300070 (China); Xu, Zhelong, E-mail: zxu@tmu.edu.cn [Department of Physiology & Pathophysiology, Tianjin Medical University, Tianjin 300070 (China)

    2016-01-01

    Morphine may induce cardioprotection by targeting mitochondria, but little is known about the exact mitochondrial events that mediate morphine's protection. We aimed to address the role of the mitochondrial Src tyrosine kinase in morphine's protection. Isolated rat hearts were subjected to 30 min ischemia and 2 h of reperfusion. Morphine was given before the onset of ischemia. Infarct size and troponin I release were measured to evaluate cardiac injury. Oxidative stress was evaluated by measuring mitochondrial protein carbonylation and mitochondrial ROS generation. HL-1 cells were subjected to simulated ischemia/reperfusion and LDH release and mitochondrial membrane potential (ΔΨm) were measured. Morphine reduced infarct size as well as cardiac troponin I release which were aborted by the selective Src tyrosine kinase inhibitors PP2 and Src-I1. Morphine also attenuated LDH release and prevented a loss of ΔΨm at reperfusion in a Src tyrosine kinase dependent manner in HL-1 cells. However, morphine failed to reduce LDH release in HL-1 cells transfected with Src siRNA. Morphine increased mitochondrial Src phosphorylation at reperfusion and this was abrogated by PP2. Morphine attenuated mitochondrial protein carbonylation and mitochondrial superoxide generation at reperfusion through Src tyrosine kinase. The inhibitory effect of morphine on the mitochondrial complex I activity was reversed by PP2. These data suggest that morphine induces cardioprotection by preventing mitochondrial oxidative stress through mitochondrial Src tyrosine kinase. Inhibition of mitochondrial complex I at reperfusion by Src tyrosine kinase may account for the prevention of mitochondrial oxidative stress by morphine. - Highlights: • Morphine induced mito-Src phosphorylation and reduced infarct size in rat hearts. • Morphine failed to reduce I/R-induced LDH release in Src-silencing HL-1 cells. • Morphine prevented mitochondria damage caused by I/R through Src. • Morphine

  17. Introduction to reversible computing

    CERN Document Server

    Perumalla, Kalyan S

    2013-01-01

    Few books comprehensively cover the software and programming aspects of reversible computing. Filling this gap, Introduction to Reversible Computing offers an expanded view of the field that includes the traditional energy-motivated hardware viewpoint as well as the emerging application-motivated software approach. Collecting scattered knowledge into one coherent account, the book provides a compendium of both classical and recently developed results on reversible computing. It explores up-and-coming theories, techniques, and tools for the application of rever

  18. The treatment of chronic intestinal ischemia.

    Science.gov (United States)

    Illuminati, G; Caliò, F G; D'Urso, A; Papaspyropoulos, V; Mancini, P; Ceccanei, G; Vietri, F

    2004-01-01

    Due to the rarity of the condition, large and prospective series defining the optimal method of digestive arteries revascularization, for the treatment of chronic intestinal ischemia, are lacking. The aim of this consecutive sample clinical study was to test the hypothesis that flexible application of different revascularization methods, according to individual cases, will yield the best results in the management of chronic intestinal ischemia. Eleven patients, of a mean age of 57 years, underwent revascularization of 11 digestive arteries for symptomatic chronic mesenteric occlusive disease. Eleven superior mesenteric arteries and one celiac axis were revascularized. The revascularization techniques included retrograde bypass grafting in 7 cases, antegrade bypass grafting in 2, percutaneous arterial angioplasty in 1, and arterial reimplantation in one case. The donor axis for either reimplantation or bypass grafting was the infrarenal aorta in 4 cases, an infrarenal Dacron graft in 4, and the celiac aorta in one case. Grafting materials included 5 polytetrafluoroethylene (PTFE) and 3 Dacron grafts. Concomitant procedures included 3 aorto-ilio-femoral grafts and one renal artery revascularization. Mean follow-up length was 31 months. There was no operative mortality. Cumulative survival rate was 88.9% at 36 months (SE 12.1%). Primary patency rate was 90% at 36 months (SE 11.6%). The symptom free rate was 90% at 36 months (SE 11.6%). Direct reimplantation, antegrade and retrograde bypass grafting, all allow good mid-term results: the choice of the optimal method depends on the anatomic and general patients status. Associated infrarenal and renal arterial lesions can be safely treated in the same time of digestive revascularization. Angioplasty alone yields poor results and should be limited to patients at poor risk for surgery.

  19. Evaluation of outcome in Mesenteric Ischemia

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    Samad Shams Vahdati

    2017-04-01

    Full Text Available Background: Acute mesenteric ischemia (AMI is an infrequent but a complicated life threatening condition. It is the leading causes of mortality with the rate of 60-100%. The purpose of our study is to investigate demographic outcomes of the patients referred to the emergency department of Imam Reza hospital with the diagnosis of AMI. Methods and materials: All patients with the diagnosis of AMI from March 2014 to March 2016 who were referred to emergency department of Imam Reza hospital, were studied. Demographic characteristics (age, sex, the period from symptom onset till laparotomy, risk factors and the last outcomes of patients were noted in the check lists for each patient. P value less than 0.05 was determined as significant. Results: from 111 patients, 76 cases (68.8% were male, 35 cases (31.5% were female. Chief complaint of all patients was stomachache. Period of arriving to the emergency room in 5 cases (4.5% was 1-6 hours, in 3 cases (2.7% was 6-12 hours, and in 103 cases (92.8% has taken more than 12 hours. In 55 cases (49.5%, there was a significant relationship between clinical signs and physical examination findings, whereas in 56 cases (50.5% there was no relation. In our study 42 cases (37.8% were treated, whereas the morbidity and mortality rate were respectively 7 (6.3% and 62 (55.9%. According to the results of our study the most important finding was pain which was disproportionate to physical examination findings (P value< 0.052. Conclusion: Acute mesenteric ischemia is a severe and progressive disease so early diagnosis and appropriate treatment are very important. One of the main reasons of higher mortality rate in AMI is difficulty in early diagnosis, before necrosis occurrence. Major factor that determines the survival rate is the accurate diagnosis before necrosis and peritonitis happens.

  20. Impaired visual short-term memory capacity is distinctively associated with structural connectivity of the posterior thalamic radiation and the splenium of the corpus callosum in preterm-born adults.

    Science.gov (United States)

    Menegaux, Aurore; Meng, Chun; Neitzel, Julia; Bäuml, Josef G; Müller, Hermann J; Bartmann, Peter; Wolke, Dieter; Wohlschläger, Afra M; Finke, Kathrin; Sorg, Christian

    2017-04-15

    Preterm birth is associated with an increased risk for lasting changes in both the cortico-thalamic system and attention; however, the link between cortico-thalamic and attention changes is as yet little understood. In preterm newborns, cortico-cortical and cortico-thalamic structural connectivity are distinctively altered, with increased local clustering for cortico-cortical and decreased integrity for cortico-thalamic connectivity. In preterm-born adults, among the various attention functions, visual short-term memory (vSTM) capacity is selectively impaired. We hypothesized distinct associations between vSTM capacity and the structural integrity of cortico-thalamic and cortico-cortical connections, respectively, in preterm-born adults. A whole-report paradigm of briefly presented letter arrays based on the computationally formalized Theory of Visual Attention (TVA) was used to quantify parameter vSTM capacity in 26 preterm- and 21 full-term-born adults. Fractional anisotropy (FA) of posterior thalamic radiations and the splenium of the corpus callosum obtained by diffusion tensor imaging were analyzed by tract-based spatial statistics and used as proxies for cortico-thalamic and cortico-cortical structural connectivity. The relationship between vSTM capacity and cortico-thalamic and cortico-cortical connectivity, respectively, was significantly modified by prematurity. In full-term-born adults, the higher FA in the right posterior thalamic radiation the higher vSTM capacity; in preterm-born adults this FA-vSTM-relationship was inversed. In the splenium, higher FA was correlated with higher vSTM capacity in preterm-born adults, whereas no significant relationship was evident in full-term-born adults. These results indicate distinct associations between cortico-thalamic and cortico-cortical integrity and vSTM capacity in preterm-and full-term-born adults. Data suggest compensatory cortico-cortical fiber re-organization for attention deficits after preterm delivery

  1. Cerebro-retinal ischemia after bilateral occlusion of internal carotid artery

    International Nuclear Information System (INIS)

    Bogousslavsky, J.; Regli, F.

    1985-01-01

    Six patients with occlusion of internal carotid arteries (ICAs) were prospectively followed during a mean period of 14 months. Prior to demonstration of occlusions, four patients suffered a mild stroke, and three isolated transient ischemic attacks (TIAs) or amaurosis fugax. All patients remained alive and with an unchanged functional ability. During follow-up, one patient suffered amaurosis fugax and TIAs followed by a mild stroke, three suffered isolated TIAs or amaurosis fugax, two suffered reversible cerebro-retinal ischemia of more than 24 hours, and one remained symptomfree. In three cases, delayed cerebro-retinal ischemia distal to one of the occluded ICAs was systematically triggered by orthostatic, cardiogenic or iatrogenic hypotension, and resolved after adequate medical treatment or restoration of a functional collateral circulation by endarterectomy of a tightly stenosed ipsilateral external carotid artery (ECA), suggesting hemodynamic phenomena. In three cases, micro-emboli originating from a stump or an ulcerated ipsilateral common carotid artery and migrating through well-developed ECA collateral channels explained delayed episodes of ipsilateral TIAs or amaurosis fugax, which disappeared in two cases after adequate anticoagulant therepy was introduced. Bilateral occlusion of ICA may be a relatively benign condition, if the patients are carefully controlled and treated. (orig.)

  2. Reversibility of female sterilization.

    Science.gov (United States)

    Siegler, A M; Hulka, J; Peretz, A

    1985-04-01

    The discussion considers the current status of reversibility of sterilization in the US and describes clinical and experimental efforts for developing techniques designed for reversibility. It focuses on regret following sterilization, reversal potential of current sterilization techniques, patient selection, current reversal techniques, results of sterilization procedures, experimental approaches to reversal of current techniques of sterilization, and sterilization procedures devised for reversibility, in humans and in animals. Request is the 1st stage of reversal, but a request for sterilization reversal (SR) does not always mean regret for a decision made at the time. Frequently it is a wish to restore fertility because life circumstances have changed after a sterilization that was ppropriate at the time it was performed. Schwyhart and Kutner reviewed 22 studies published between 1949-69 in which they found that the percentage of patients regretting the procedure ranged from 1.3-15%. Requests for reversal remain low in most countries, but if sterilization becomes a more popular method of contraception, requests will also increase. The ideal operation considered as a reversaible method of sterilization should include an easy, reliable outpatient method of tubal occlusion with miniml risk or patient discomfort that subsequently could be reversed without the need for a major surgical intervention. Endoscopic methods have progressed toward the 1st objective. A recent search of the literature uncovered few series of SR of more than 50 cases. The 767 operations found were analyzed with regard to pregnancy outcome. The precent of live births varied from 74-78.8%, and the occurance of tubal pregnancies ranged from 1.7-6.5%. All of the confounding variables in patient selection and small numbers of reported procedures preclude any conclusion about the different techniques or the number of operations that give a surgeon a level of expertise. Few authors classify their

  3. Strong, reliable and precise synaptic connections between thalamic relay cells and neurones of the nucleus reticularis in juvenile rats

    Science.gov (United States)

    Gentet, Luc J; Ulrich, Daniel

    2003-01-01

    The thalamic reticular nucleus (nRT) is composed entirely of GABAergic inhibitory neurones that receive input from pyramidal cortical neurones and excitatory relay cells of the ventrobasal complex of the thalamus (VB). It plays a major role in the synchrony of thalamic networks, yet the synaptic connections it receives from VB cells have never been fully physiologically characterised. Here, whole-cell current-clamp recordings were obtained from 22 synaptically connected VB-nRT cell pairs in slices of juvenile (P14–20) rats. At 34–36 °C, single presynaptic APs evoked unitary EPSPs in nRT cells with a peak amplitude of 7.4 ± 1.5 mV (mean ± s.e.m.) and a decay time constant of 15.1 ± 0.9 ms. Only four out of 22 pairs showed transmission failures at a mean rate of 6.8 ± 1.1 %. An NMDA receptor (NMDAR)-mediated component was significant at rest and subsequent EPSPs in a train were depressed. Only one out of 14 pairs tested was reciprocally connected; the observed IPSPs in the VB cell had a peak amplitude of 0.8 mV and were completely abolished in the presence of 10 μm bicuculline. Thus, synaptic connections from VB cells to nRT neurones are mainly ‘drivers’, while a small subset of cells form closed disynaptic loops. PMID:12563005

  4. The effects of Thalamic Deep Brain Stimulation on speech dynamics in patients with Essential Tremor: An articulographic study.

    Directory of Open Access Journals (Sweden)

    Doris Mücke

    Full Text Available Acoustic studies have revealed that patients with Essential Tremor treated with thalamic Deep Brain Stimulation (DBS may suffer from speech deterioration in terms of imprecise oral articulation and reduced voicing control. Based on the acoustic signal one cannot infer, however, whether this deterioration is due to a general slowing down of the speech motor system (e.g., a target undershoot of a desired articulatory goal resulting from being too slow or disturbed coordination (e.g., a target undershoot caused by problems with the relative phasing of articulatory movements. To elucidate this issue further, we here investigated both acoustics and articulatory patterns of the labial and lingual system using Electromagnetic Articulography (EMA in twelve Essential Tremor patients treated with thalamic DBS and twelve age- and sex-matched controls. By comparing patients with activated (DBS-ON and inactivated stimulation (DBS-OFF with control speakers, we show that critical changes in speech dynamics occur on two levels: With inactivated stimulation (DBS-OFF, patients showed coordination problems of the labial and lingual system in terms of articulatory imprecision and slowness. These effects of articulatory discoordination worsened under activated stimulation, accompanied by an additional overall slowing down of the speech motor system. This leads to a poor performance of syllables on the acoustic surface, reflecting an aggravation either of pre-existing cerebellar deficits and/or the affection of the upper motor fibers of the internal capsule.

  5. Nonlinear predictive control for adaptive adjustments of deep brain stimulation parameters in basal ganglia-thalamic network.

    Science.gov (United States)

    Su, Fei; Wang, Jiang; Niu, Shuangxia; Li, Huiyan; Deng, Bin; Liu, Chen; Wei, Xile

    2018-02-01

    The efficacy of deep brain stimulation (DBS) for Parkinson's disease (PD) depends in part on the post-operative programming of stimulation parameters. Closed-loop stimulation is one method to realize the frequent adjustment of stimulation parameters. This paper introduced the nonlinear predictive control method into the online adjustment of DBS amplitude and frequency. This approach was tested in a computational model of basal ganglia-thalamic network. The autoregressive Volterra model was used to identify the process model based on physiological data. Simulation results illustrated the efficiency of closed-loop stimulation methods (amplitude adjustment and frequency adjustment) in improving the relay reliability of thalamic neurons compared with the PD state. Besides, compared with the 130Hz constant DBS the closed-loop stimulation methods can significantly reduce the energy consumption. Through the analysis of inter-spike-intervals (ISIs) distribution of basal ganglia neurons, the evoked network activity by the closed-loop frequency adjustment stimulation was closer to the normal state. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Engineering a thalamo-cortico-thalamic circuit on SpiNNaker: a preliminary study towards modelling sleep and wakefulness

    Directory of Open Access Journals (Sweden)

    Basabdatta Sen Bhattacharya

    2014-05-01

    Full Text Available We present a preliminary study of a thalamo-cortico-thalamic (TCT implementation on SpiNNaker (Spiking Neural Network architecture, a brain inspired hardware platform designed to incorporate the inherent biological properties of parallelism, fault tolerance and energy efficiency. These attributes make SpiNNaker an ideal platform for simulating biologically plausible computational models. Our focus in this work is to design a TCT framework that can be simulated on SpiNNaker to mimic dynamical behaviour similar to Electroencephalogram (EEG time and power-spectra signatures in sleep-wake transition. The scale of the model is minimised for simplicity in this proof-of-concept study; thus the total number of spiking neurons is approximately 1000 and represents a `mini-column' of the thalamocortical tissue. All data on model structure, synaptic layout and parameters is inspired from previous studies and abstracted at a level that is appropriate to the aims of the current study as well as computationally suitable for model simulation on a small 4-chip SpiNNaker system. The initial results from selective deletion of synaptic connectivity parameters in the model show similarity with EEG time series characteristics of sleep and wakefulness. These observations provide a positive perspective and a basis for future implementation of a very large scale biologically plausible model of thalamo-cortico-thalamic interactivity---the essential brain circuit that regulates the biological sleep-wake cycle and associated EEG rhythms.

  7. Discontinuous Galerkin finite element method for solving population density functions of cortical pyramidal and thalamic neuronal populations.

    Science.gov (United States)

    Huang, Chih-Hsu; Lin, Chou-Ching K; Ju, Ming-Shaung

    2015-02-01

    Compared with the Monte Carlo method, the population density method is efficient for modeling collective dynamics of neuronal populations in human brain. In this method, a population density function describes the probabilistic distribution of states of all neurons in the population and it is governed by a hyperbolic partial differential equation. In the past, the problem was mainly solved by using the finite difference method. In a previous study, a continuous Galerkin finite element method was found better than the finite difference method for solving the hyperbolic partial differential equation; however, the population density function often has discontinuity and both methods suffer from a numerical stability problem. The goal of this study is to improve the numerical stability of the solution using discontinuous Galerkin finite element method. To test the performance of the new approach, interaction of a population of cortical pyramidal neurons and a population of thalamic neurons was simulated. The numerical results showed good agreement between results of discontinuous Galerkin finite element and Monte Carlo methods. The convergence and accuracy of the solutions are excellent. The numerical stability problem could be resolved using the discontinuous Galerkin finite element method which has total-variation-diminishing property. The efficient approach will be employed to simulate the electroencephalogram or dynamics of thalamocortical network which involves three populations, namely, thalamic reticular neurons, thalamocortical neurons and cortical pyramidal neurons. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Clinical appraisal of stereotactic hematoma aspiration surgery for hypertensive thalamic hemorrhage; With respect to volume of the hematoma

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Koji; Matsumoto, Keizo (Tokushima Univ. (Japan). School of Medicine)

    1992-06-01

    Three hundred and four patients with hypertensive thalamic hemorrhage were managed by medical treatment, ventricular drainage, or CT-controlled stereotactic aspiration surgery (AS). The therapeutic results of the 6-month outcome were analyzed and correlated with the volume of the hematoma. A hematoma volume of 20 ml was thought to be the critical size in determining whether the outcome would be favorable or unfavorable. Indications for AS are suggested as follows. In patients with a small-sized hematoma having a volume of less than 10 ml use of AS should be restricted to patients with severe paralysis or other neurological complications and the elderly (aged 70 years or older). For patients with a medium-sized hematoma having a volume between 10 ml and 20 ml, AS is indicated for patients having severe paralysis and disturbances of consciousness. For patients with a large-sized hematoma having a volume of 20 ml or more, AS increases not only the survival rate of patients but also reduces the number of bedridden patients. We conclude that AS opens up a new avenue of surgical treatment for hypertensive thalamic hemorrhage, which has been no indication for hematoma evacuation by conventional craniotomy. (author).

  9. The pacemaker role of thalamic reticular nucleus in controlling spike-wave discharges and spindles

    Science.gov (United States)

    Fan, Denggui; Liao, Fucheng; Wang, Qingyun

    2017-07-01

    Absence epilepsy, characterized by 2-4 Hz spike-wave discharges (SWDs), can be caused by pathological interactions within the thalamocortical system. Cortical spindling oscillations are also demonstrated to involve the oscillatory thalamocortical rhythms generated by the synaptic circuitry of the thalamus and cortex. This implies that SWDs and spindling oscillations can share the common thalamocortical mechanism. Additionally, the thalamic reticular nucleus (RE) is hypothesized to regulate the onsets and propagations of both the epileptic SWDs and sleep spindles. Based on the proposed single-compartment thalamocortical neural field model, we firstly investigate the stimulation effect of RE on the initiations, terminations, and transitions of SWDs. It is shown that the activations and deactivations of RE triggered by single-pulse stimuli can drive the cortical subsystem to behave as the experimentally observed onsets and self-abatements of SWDs, as well as the transitions from 2-spike and wave discharges (2-SWDs) to SWDs. In particular, with increasing inhibition from RE to the specific relay nucleus (TC), rich transition behaviors in cortex can be obtained through the upstream projection path, RE → TC → Cortex . Although some of the complex dynamical patterns can be expected from the earlier single compartment thalamocortical model, the effect of brain network topology on the emergence of SWDs and spindles, as well as the transitions between them, has not been fully investigated. We thereby develop a spatially extended 3-compartment coupled network model with open-/closed-end connective configurations, to investigate the spatiotemporal effect of RE on the SWDs and spindles. Results show that the degrees of activations of RE 1 can induce the rich spatiotemporal evolution properties including the propagations from SWDs to spindles within different compartments and the transitions between them, through the RE 1 → TC 1 → Cortex 1 and Cortex 1 → Cortex 2

  10. The pacemaker role of thalamic reticular nucleus in controlling spike-wave discharges and spindles.

    Science.gov (United States)

    Fan, Denggui; Liao, Fucheng; Wang, Qingyun

    2017-07-01

    Absence epilepsy, characterized by 2-4 Hz spike-wave discharges (SWDs), can be caused by pathological interactions within the thalamocortical system. Cortical spindling oscillations are also demonstrated to involve the oscillatory thalamocortical rhythms generated by the synaptic circuitry of the thalamus and cortex. This implies that SWDs and spindling oscillations can share the common thalamocortical mechanism. Additionally, the thalamic reticular nucleus (RE) is hypothesized to regulate the onsets and propagations of both the epileptic SWDs and sleep spindles. Based on the proposed single-compartment thalamocortical neural field model, we firstly investigate the stimulation effect of RE on the initiations, terminations, and transitions of SWDs. It is shown that the activations and deactivations of RE triggered by single-pulse stimuli can drive the cortical subsystem to behave as the experimentally observed onsets and self-abatements of SWDs, as well as the transitions from 2-spike and wave discharges (2-SWDs) to SWDs. In particular, with increasing inhibition from RE to the specific relay nucleus (TC), rich transition behaviors in cortex can be obtained through the upstream projection path, RE→TC→Cortex. Although some of the complex dynamical patterns can be expected from the earlier single compartment thalamocortical model, the effect of brain network topology on the emergence of SWDs and spindles, as well as the transitions between them, has not been fully investigated. We thereby develop a spatially extended 3-compartment coupled network model with open-/closed-end connective configurations, to investigate the spatiotemporal effect of RE on the SWDs and spindles. Results show that the degrees of activations of RE 1 can induce the rich spatiotemporal evolution properties including the propagations from SWDs to spindles within different compartments and the transitions between them, through the RE 1 →TC 1 →Cortex 1 and Cortex 1 →Cortex 2 →Cortex 3

  11. Longitudinal development of thalamic and internal capsule microstructure in autism spectrum disorder.

    Science.gov (United States)

    McLaughlin, Kristine; Travers, Brittany G; Dadalko, Olga I; Dean, Douglas C; Tromp, Do; Adluru, Nagesh; Destiche, Daniel; Freeman, Abigail; Prigge, Molly D; Froehlich, Alyson; Duffield, Tyler C; Zielinski, Brandon A; Bigler, Erin D; Lange, Nicholas; Anderson, Jeff S; Alexander, Andrew L; Lainhart, Janet E

    2018-03-01

    childhood, thalamic microstructure was distinct in the ASD group compared to the typically developing group. However, these group differences appeared to narrow with age, suggesting that the thalamus continues to dynamically change in ASD into adulthood. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

  12. Pathways for Emotions: Specializations in the Amygdalar, Mediodorsal Thalamic, and Posterior Orbitofrontal Network.

    Science.gov (United States)

    Timbie, Clare; Barbas, Helen

    2015-08-26

    The primate amygdala projects to posterior orbitofrontal cortex (pOFC) directly and possibly indirectly through a pathway to the magnocellular mediodorsal thalamic nucleus (MDmc), which may convey signals about the significance of stimuli. However, because MDmc receives input from structures in addition to the amygdala and MDmc projects to areas in addition to pOFC, it is unknown whether amygdalar pathways in MDmc innervate pOFC-bound neurons. We addressed this issue using double- or triple-labeling approaches to identify pathways and key cellular and molecular features in rhesus monkeys. We found that amygdalar terminations innervated labeled neurons in MDmc that project to pOFC. Projection neurons in MDmc directed to pOFC included comparatively fewer "core" parvalbumin neurons that project focally to the middle cortical layers and more "matrix" calbindin neurons that project expansively to the upper cortical layers. In addition, a small and hitherto unknown pathway originated from MDmc calretinin neurons and projected to pOFC. Further, whereas projection neurons directed to MDmc and to pOFC were intermingled in the amygdala, none projected to both structures. Larger amygdalar neurons projected to MDmc and expressed the vesicular glutamate transporter 2 (VGLUT2), which is found in highly efficient "driver" pathways. In contrast, smaller amygdalar neurons directed to pOFC expressed VGLUT1 found in modulatory pathways. The indirect pathway from the amygdala to pOFC via MDmc may provide information about the emotional significance of events and, along with a parallel direct pathway, ensures transfer of signals to all layers of pOFC. The amygdala-the brain's center for emotions-is strongly linked with the orbital cortex, a region associated with social interactions. This study provides evidence that a robust pathway from the amygdala reaches neurons in the thalamus that link directly with the orbital cortex, forming a tight tripartite network. The dual pathways from

  13. Altered structural connectivity of cortico-striato-pallido-thalamic networks in Gilles de la Tourette syndrome.

    Science.gov (United States)

    Worbe, Yulia; Marrakchi-Kacem, Linda; Lecomte, Sophie; Valabregue, Romain; Poupon, Fabrice; Guevara, Pamela; Tucholka, Alan; Mangin, Jean-François; Vidailhet, Marie; Lehericy, Stephane; Hartmann, Andreas; Poupon, Cyril

    2015-02-01

    -frontal cortex, inferior frontal, temporo-parietal junction, medial temporal and frontal pole also had enhanced structural connectivity with the striatum and thalamus in patients with Gilles de la Tourette syndrome. In addition, the cortico-striatal pathways were characterized by elevated fractional anisotropy and diminished radial diffusivity, suggesting microstructural axonal abnormalities of white matter in Gilles de la Tourette syndrome. These changes were more prominent in females with Gilles de la Tourette syndrome compared to males and were not related to the current medication status. Taken together, our data showed widespread structural abnormalities in cortico-striato-pallido-thalamic white matter pathways in patients with Gilles de la Tourette, which likely result from abnormal brain development in this syndrome. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain.

  14. Protective effect of salvianolic acid B against intestinal ischemia ...

    African Journals Online (AJOL)

    transplantation, strangulated hernias due to gastric barrier ... using pentabarbital sodium at the dose of 50 ..... prevents iodinated contrast media-induced acute renal injury in rats via ... mesenchymal stem cells reduce rat intestinal ischemia-.

  15. Myocardial ischemia in hypertrophic cardiomyopathy; Isquemia miocardica na cardiomiopatia hipertrofica

    Energy Technology Data Exchange (ETDEWEB)

    Lima Filho, Moyses de Oliveira; Figueiredo, Geraldo L.; Simoes, Marcus V.; Pyntia, Antonio O.; Marin Neto, Jose Antonio [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Div. de Cardiologia

    2000-08-01

    Myocardial ischemia in hypertrophic cardiomyopathy is multifactorial and explains the occurrence of angina, in about 50% of patients. The pathophysiology of myocardial ischemia may be explained by the increase of the ventricular mass and relative paucity of the coronary microcirculation; the elevated ventricular filling pressures and myocardial stiffness causing a compression of the coronary microvessels; the impaired coronary vasodilator flow reserve caused by anatomic and functional abnormalities; and the systolic compression of epicardial vessel (myocardial bridges). Myocardial ischemia must be investigated by perfusion scintigraphic methods since its presence influences the prognosis and has relevant clinical implications for management of patients. Patients with hypertrophic cardiomyopathy and documented myocardial ischemia usually need to undergo invasive coronary angiography to exclude the presence of concomitant atherosclerotic coronary disease. (author)

  16. Quantitative Ischemia Detection During Cardiac MR Stress Testing

    National Research Council Canada - National Science Library

    Kraitchman, D

    2001-01-01

    .... During a second ischemic episode, conventional cine wall motion images were acquired. The time from occlusion to the detection of ischemia by each MR technique, as well as ECG ischemic alterations, was determined...

  17. Current technology in assessing painless and painful ischemia

    International Nuclear Information System (INIS)

    Selwyn, A.P.

    1990-01-01

    Recent technologic advances have yielded diverse techniques for studying myocardial ischemia, a useful functional expression of coronary artery disease. These techniques have revealed new characteristics and expanded our understanding of myocardial ischemia. In turn this has led to the establishment of more realistic and discriminating criteria on which to base diagnostic and management decisions. Many of the techniques are noninvasive and can be performed in the cardiologist's office. These include treadmill exercise testing; radioisotope techniques, including ejection fraction studies, stress thallium scintigraphy, and tomographic imaging; and ambulatory monitoring. Other, newer techniques include provocative tests that induce ischemia in patients who cannot exercise. These new noninvasive tests should be used to detect transient ischemia, estimate its severity, and thus record a measure of the patient's risk for adverse coronary events

  18. Prognostic importance of silent myocardial ischemia detected by intravenous dipyridamole thallium myocardial imaging in asymptomatic patients with coronary artery disease

    International Nuclear Information System (INIS)

    Younis, L.T.; Byers, S.; Shaw, L.; Barth, G.; Goodgold, H.; Chaitman, B.R.

    1989-01-01

    One hundred seven asymptomatic patients who underwent intravenous dipyridamole thallium imaging were evaluated to determine prognostic indicators of subsequent cardiac events over an average follow-up period of 14 +/- 10 months. Univariate analysis of 18 clinical, scintigraphic and angiographic variables revealed that a reversible thallium defect, a combined fixed and reversible thallium defect, number of segmental thallium defects and extent of coronary artery disease were significant predictors of subsequent cardiac events. Of the 13 patients who died or had a nonfatal infarction, 12 had a reversible thallium defect. Stepwise logistic regression analysis selected a reversible thallium defect as the only significant predictor of cardiac events. When death or myocardial infarction was the outcome variable, a combined fixed and reversible thallium defect was the only predictor of outcome. In patients without previous myocardial infarction, the cardiac event rate was significantly greater in those with an abnormal versus normal thallium scan (55% versus 12%, p less than 0.001). Thus, intravenous dipyridamole thallium scintigraphy is a useful noninvasive test to risk stratify asymptomatic patients with coronary artery disease. A reversible thallium defect most likely indicates silent myocardial ischemia in a sizable fraction of patients in this clinical subset and is associated with an unfavorable prognosis

  19. Chinese herbal formula Tongluo Jiunao injection protects against cerebral ischemia by activating neurotrophin 3/tropomyosin-related kinase C pathway

    Directory of Open Access Journals (Sweden)

    Peiman Alesheikh

    2015-01-01

    Full Text Available The Chinese herbal formula Tongluo Jiunao, containing the active components Panax notoginseng and Gardenia jasminoides, has recently been patented and is in use clinically. It is known to be neuroprotective in cerebral ischemia, but the underlying pathway remains poorly understood. In the present study, we established a rat model of cerebral ischemia by occlusion of the middle cerebral artery, and administered Tongluo Jiunao, a positive control (Xuesai Tong, containing Panax notoginseng or saline intraperitoneally to investigate the pathway involved in the action of Tongluo Jiunao injection. 2,3,5-Triphenyltetrazolium chloride (TTC staining showed that the cerebral infarct area was significantly smaller in model rats that received Tongluo Jiunao than in those that received saline. Enzyme-linked immunosorbent assay revealed significantly greater expression of neurotrophin 3 and growth-associated protein 43 in ischemic cerebral tissue, and serum levels of neurotrophin 3, in the Tongluo Jiunao group than in the saline group. The reverse transcription polymerase chain reaction and immunohistochemical staining showed that after treatment with Tongluo Jiunao or Xuesai Tong, tropomyosin-related kinase C gene expression and immunoreactivity were significantly elevated compared with saline, with the greatest expression observed after Tongluo Jiunao treatment. These findings suggest that Tongluo Jiunao injection exerts a neuroprotective effect in rats with cerebral ischemia by activating the neurotrophin 3/tropomyosin-related kinase C pathway.

  20. Paeoniflorin protects against ischemia-induced brain damages in rats via inhibiting MAPKs/NF-κB-mediated inflammatory responses.

    Directory of Open Access Journals (Sweden)

    Ruo-Bing Guo

    Full Text Available Paeoniflorin (PF, the principal component of Paeoniae Radix prescribed in traditional Chinese medicine, has been reported to exhibit many pharmacological effects including protection against ischemic injury. However, the mechanisms underlying the protective effects of PF on cerebral ischemia are still under investigation. The present study showed that PF treatment for 14 days could significantly inhibit transient middle cerebral artery occlusion (MCAO-induced over-activation of astrocytes and microglia, and prevented up-regulations of pro-inflamamtory mediators (TNFα, IL-1β, iNOS, COX(2 and 5-LOX in plasma and brain. Further study demonstrated that chronic treatment with PF suppressed the activations of JNK and p38 MAPK, but enhanced ERK activation. And PF could reverse ischemia-induced activation of NF-κB signaling pathway. Moreover, our in vitro study revealed that PF treatment protected against TNFα-induced cell apoptosis and neuronal loss. Taken together, the present study demonstrates that PF produces a delayed protection in the ischemia-injured rats via inhibiting MAPKs/NF-κB mediated peripheral and cerebral inflammatory response. Our study reveals that PF might be a potential neuroprotective agent for stroke.

  1. Paeoniflorin protects against ischemia-induced brain damages in rats via inhibiting MAPKs/NF-κB-mediated inflammatory responses.

    Science.gov (United States)

    Guo, Ruo-Bing; Wang, Guo-Feng; Zhao, An-Peng; Gu, Jun; Sun, Xiu-Lan; Hu, Gang

    2012-01-01

    Paeoniflorin (PF), the principal component of Paeoniae Radix prescribed in traditional Chinese medicine, has been reported to exhibit many pharmacological effects including protection against ischemic injury. However, the mechanisms underlying the protective effects of PF on cerebral ischemia are still under investigation. The present study showed that PF treatment for 14 days could significantly inhibit transient middle cerebral artery occlusion (MCAO)-induced over-activation of astrocytes and microglia, and prevented up-regulations of pro-inflamamtory mediators (TNFα, IL-1β, iNOS, COX(2) and 5-LOX) in plasma and brain. Further study demonstrated that chronic treatment with PF suppressed the activations of JNK and p38 MAPK, but enhanced ERK activation. And PF could reverse ischemia-induced activation of NF-κB signaling pathway. Moreover, our in vitro study revealed that PF treatment protected against TNFα-induced cell apoptosis and neuronal loss. Taken together, the present study demonstrates that PF produces a delayed protection in the ischemia-injured rats via inhibiting MAPKs/NF-κB mediated peripheral and cerebral inflammatory response. Our study reveals that PF might be a potential neuroprotective agent for stroke.

  2. IMAGE ANALYSIS IN GOMORI´S TRICHROME STAIN OF SKELETAL MUSCLES SUBJECTED TO ISCHEMIA AND REPERFUSION INJURY

    Directory of Open Access Journals (Sweden)

    Doris Haydee Rosero Salazar

    2016-06-01

    Full Text Available Conditions that produce ischemia and reperfusion injury include orthopedic surgeries, vascular diseases and accidents in remote places in which use of a manual tourniquet is required. Tissues under such stress suffer the consequences of evidenced by changes in their normal microscopic organization that can be reversible or irreversible according to the time and severity of lesion. An experimental model of ischemia has been designed taking into account the characteristics similar to a surgical procedure, from preparation for anesthesia up to the postsurgical follow up of each animal until it finishes the established time of reperfusion. Two muscles, soleus and extensor carpi radialis longus, dissected from Wistar rats that were underwent to short periods of ischemia and short and prolonged periods of reperfusion up to 32 days. There were no significant changes in the macroscopic weight of muscles, but significant differences were found in the area occupied by intramuscular extracellular matrix. During reperfusion, a partial recovery was observed until the last day of study. If we pretend to extrapolate these results to clinical areas, its importance focuses in the recovering of function and the following up of patients after surgical procedures as studied in the present experiment.

  3. [Adipose-derived stem cell transplantation promotes the expression of netrin-1 in the rat cortex after focal cerebral ischemia].

    Science.gov (United States)

    Wang, Jiehua; Hong, Zhuquan; Pan, Ying; Li, Guoqian

    2017-01-01

    Objective To observe the effect of adipose-derived stem cells (ADSCs) transplantation on the expression of netrin-1 in rats after focal cerebral ischemia. Methods Male SD rats were randomly divided into control group, model group and ADSC group. ADSCs were harvested and purified. Focal cerebral ischemia models were established in rats by the suture method. ADSCs were injected into the lateral ventricle of ADSC group rats and the same does of PBS was given to model group rats. At day 4, 7 and 14 after reperfusion, six rats were sacrificed to remove the brain tissues at each time point. The expression of netrin-1 was detected by reverse-transcription PCR, Western blotting and immunohistochemistry. Results Compared with the control group, the expression of netrin-1 in the brain tissues of the model group increased after focal cerebral ischemia, reached the peak at 4 days, and the expression of netrin-1 was significantly higher than that of the control group at each time point. Compared with the model group, the expression of netrin-1 in the ADSC group increased further, reached the peak at 7 days, and the expression of netrin-1 in the ADSC group was significantly higher than that of the model group at each time point. Conclusion ADSC transplantation could up-regulate the expression of netrin-1, and promote axon regeneration and the recovery of neurological functions.

  4. Differential regulation of iPLA2beta splice variants by in vitro ischemia in C2C12 myotubes

    DEFF Research Database (Denmark)

    Poulsen, K. A.; Kolko, M.; Lambert, I. H.

    2006-01-01

    In this study we investigated the activity, expression and regulation of iPLA2 during ischemia in mouse C2C12 myotubes. Here, we show that in vitro ischemia, i.e. oxygen deprivation and glucose starvation, induces an iPLA2 activity that is totally reversed by siRNA knock down of iPLA2£], indicating...... preferential activation of iPLA2£]. The activity of the native iPLA2£] tetramer has in humans been proposed to be negatively regulated by interactions with catalytic inactive splice variants of the full-length protein. These variants, characterized by the presence exon 9a, have however not been identified...... of this transcript would be a C-terminally truncated î50 kDa protein lacking the catalytic site. qPCR indicated that, while the total iPLA2£] mRNA level in C2C12 myotubes increased weakly within 1-2 hours of in vitro ischemia, the transcript containing the mouse exon 9a was rapidly down regulated. In addition...

  5. Social cognitive and neurocognitive deficits in inpatients with unilateral thalamic lesions — pilot study

    Directory of Open Access Journals (Sweden)

    Wilkos E

    2015-04-01

    Full Text Available Ewelina Wilkos,2 Timothy JB Brown,3 Ksenia Slawinska,1 Katarzyna A Kucharska2,3 1Department of Neurology, 2Department of Neuroses, Personality and Eating Disorders Institute of Psychiatry and Neurology, Warsaw, Poland; 3Department of Medical Education, Hull York Medical School, Hull, UK Background: The essential role of the thalamus in neurocognitive processes has been well documented. In contrast, relatively little is known about its involvement in social cognitive processes such as recognition of emotion, mentalizing, or empathy. The aim of the study: This study was designed to compare the performance of eight patients (five males, three females, mean age ± SD: 63.7±7.9 years at early stage of unilateral thalamic lesions and eleven healthy controls (six males, five females, 49.6±12.2 years in neurocognitive tests (CogState Battery: Groton Maze Learning Test, GML; Groton Maze Learning Test-Delayed Recall, GML-DR; Detection Task, DT; Identification Task, IT; One Card Learning Task, OCLT; One Back Task, OBT; Two Back Task, TBT; Set-Shifting Task, S-ST and other well-known tests (Benton Visual Retention Test, BVRT; California Verbal Learning Test, CVLT; The Rey-Osterrieth Complex Figure Test, ROCF; Trail Making Test, TMT part A and B; Color – Word Stroop Task, CWST; Verbal Fluency Test, VFT, and social cognitive tasks (The Penn Emotion Recognition Test, ER40; Penn Emotion Discrimination Task, EmoDiff40; The Penn Emotional Acuity Test, PEAT40; Reading the Mind in the Eyes Test, revised version II; Toronto Alexithymia Scale, TAS-20. Methods: Thalamic-damaged subjects were included if they experienced a single-episode ischemic stroke localized in right or left thalamus. The patients were examined at 3 weeks after the stroke onset. All were right handed. In addition, the following clinical scales were used: the Mini-Mental State Examination (MMSE, Spielberger State-Trait Anxiety Inventory (STAI, Beck Depression Inventory (BDI II. An inclusion

  6. MICROCIRCULATORY ISCHEMIA AND STATINS: LESSONS OF INTERVENTION CARDIOLOGY

    Directory of Open Access Journals (Sweden)

    An. A. Alexandrov

    2015-12-01

    Full Text Available Review is devoted to the pathogenesis of microcirculatory ischemia. Microcirculatory dysfunction has been identified in different groups of patients including syndrome X, diabetes mellitus 2 type, coronary heart disease. In coronary patients after transluminal angioplasty microcirculatory dysfunction is the reason of phenomenon of “non-reflow”. In result the procedure of revascularization is less effective. Therapy by statins can be beneficial for patients with microcirculatory ischemia.

  7. Spinal cord ischemia following thoracotomy without epidural anesthesia.

    Science.gov (United States)

    Raz, Aeyal; Avramovich, Aharon; Saraf-Lavi, Efrat; Saute, Milton; Eidelman, Leonid A

    2006-06-01

    Paraplegia is an uncommon yet devastating complication following thoracotomy, usually caused by compression or ischemia of the spinal cord. Ischemia without compression may be a result of global ischemia, vascular injury and other causes. Epidural anesthesia has been implicated as a major cause. This report highlights the fact that perioperative cord ischemia and paraplegia may be unrelated to epidural intervention. A 71-yr-old woman was admitted for a left upper lobectomy for resection of a non-small cell carcinoma of the lung. The patient refused epidural catheter placement and underwent a left T5-6 thoracotomy under general anesthesia. During surgery, she was hemodynamically stable and good oxygen saturation was maintained. Several hours following surgery the patient complained of loss of sensation in her legs. Neurological examination disclosed a complete motor and sensory block at the T5-6 level. Magnetic resonance imaging (MRI) revealed spinal cord ischemia. The patient received iv steroid treatment, but remained paraplegic. Five months following the surgery there was only partial improvement in her motor symptoms. A follow-up MRI study was consistent with a diagnosis of spinal cord ischemia. In this case of paraplegia following thoracic surgery for lung resection, epidural anesthesia/analgesia was not used. The MRI demonstrated evidence of spinal cord ischemia, and no evidence of cord compression. This case highlights that etiologies other than epidural intervention, such as injury to the spinal segmental arteries during thoracotomy, should be considered as potential causes of cord ischemia and resultant paraplegia in this surgical population.

  8. Cerebral Ischemia Due to Traumatic Carotid Artery Dissection: Case Report

    OpenAIRE

    Deniz Kamacı Şener; Özlem Taşkapılıoğlu; Nermin Kelebek Girgin; Bahattin Hakyemez; Mustafa Bakar; Yakup Tomak

    2012-01-01

    Blunt injury to the neck region may lead to carotid artery dissection and cerebral ischemia. Blunt injury to carotid artery is not frequent but determination of the presence of trauma in the history of stroke patients will provide early diagnosis and treatment of them. In this article, a case with cerebral ischemia resulting from traumatic carotid artery dissection is presented and clinical findings, diagnostic procedures and choice of treatment are discussed in the light of the literature.

  9. Cerebral Ischemia Due to Traumatic Carotid Artery Dissection: Case Report

    Directory of Open Access Journals (Sweden)

    Deniz Kamacı Şener

    2012-12-01

    Full Text Available Blunt injury to the neck region may lead to carotid artery dissection and cerebral ischemia. Blunt injury to carotid artery is not frequent but determination of the presence of trauma in the history of stroke patients will provide early diagnosis and treatment of them. In this article, a case with cerebral ischemia resulting from traumatic carotid artery dissection is presented and clinical findings, diagnostic procedures and choice of treatment are discussed in the light of the literature.

  10. Quantum reverse hypercontractivity

    Energy Technology Data Exchange (ETDEWEB)

    Cubitt, Toby [Department of Computer Science, University College London, London, United Kingdom and Centre for Quantum Information and Foundations, DAMTP, University of Cambridge, Cambridge (United Kingdom); Kastoryano, Michael [NBIA, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Montanaro, Ashley [School of Mathematics, University of Bristol, Bristol (United Kingdom); Temme, Kristan [Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125 (United States)

    2015-10-15

    We develop reverse versions of hypercontractive inequalities for quantum channels. By generalizing classical techniques, we prove a reverse hypercontractive inequality for tensor products of qubit depolarizing channels. We apply this to obtain a rapid mixing result for depolarizing noise applied to large subspaces and to prove bounds on a quantum generalization of non-interactive correlation distillation.

  11. Atrioventricular Pacemaker Lead Reversal

    Directory of Open Access Journals (Sweden)

    Mehmet K Aktas, MD

    2007-01-01

    Full Text Available During cardiac surgery temporary epicardial atrial and ventricular leads are placed in case cardiac pacing is required postoperatively. We present the first reported series of patients with reversal of atrioventricular electrodes in the temporary pacemaker without any consequent deleterious hemodynamic effect. We review the electrocardiographic findings and discuss the findings that lead to the discovery of atrioventricular lead reversal.

  12. Reversible encephalopathy syndrome: report of 12 cases with follow-up

    International Nuclear Information System (INIS)

    Greco Crasto, S.; Sardo, P.; Davini, O.; Rizzo, L.; De Lucchi, R.

    2004-01-01

    We report the clinical and neuroradiological features of reversible encephalopathy syndrome and follow-up results in 12 patients. This syndrome seems to be the result of an acute encephalopathy showing with brain edema mainly in the white matter (vasogenic edema). Diffusion-weighted magnetic resonance images are useful to distinguish this entity from acute ischemia. Early recognition and treatment often lead to complete neurological recovery. If unrecognized, the patient's condition can progress to central nervous system failure. (orig.)

  13. Ischemia modified albumin as laboratory marker of acute

    Directory of Open Access Journals (Sweden)

    Goran Miličević

    2009-02-01

    Full Text Available Daily clinical practice still lacks a marker of acute myocardial ischemia as compared with markers ofmyocardial necrosis. Ischemia modifed albumin (IMA has recently been proposed as a useful biochemicaltool for detection of ischemia – it is a test which determines the inability of N-terminal end ofalbumin to bind cobalt during ischemia. A strong relation between IMA and early myocardial ischemiahas been shown by several studies, in most of which percutaneous coronary intervention was used asa model of myocardial ischemia, where this test showed high sensitivity. IMA values raise during nextfew minutes after the ischemia has occured, and return back to normal levels within next six hours, butthe precise dynamics of its rise and fall are still unknown. Beside defining etiology of acute or sub-acutechest pain in patients with inconclusive electrocardiogram (ECG, in patients with “silent” myocardialischemia with ischemic changes in ECG or in patients with non-ischemic ECG changes during cardiacstress test, this promising marker could also be used as the earliest biochemical indicator of early developmentof myocardial infarction. Relatively low organ-specificity is a limitation of this test, becauseIMA levels are also raised during different ischemic conditions and diseases of other organs. If thisproblem is taken into consideration, IMA test shows good results in diagnosing myocardial ischemiadue to its high sensitivity.

  14. Acute testicular ischemia caused by incarcerated inguinal hernia.

    Science.gov (United States)

    Orth, Robert C; Towbin, Alexander J

    2012-02-01

    Acute testicular ischemia caused by an incarcerated inguinal hernia usually affects infants. There are few reports of diagnosis using US, and the effect of long-standing reducible hernias on testicular growth in infants and children is unknown. The objectives of this study were to determine the incidence of testicular ischemia secondary to an incarcerated inguinal hernia at scrotal sonography and to determine the effect on testicular size at diagnosis. A hospital database was used to locate scrotal sonography examinations documenting an inguinal hernia, and images were reviewed for signs of testicular ischemia. Testicular volumes were compared using the Wilcoxon signed rank test. A total of 147 patients were identified with an inguinal hernia (age 1 day to 23 years, average 6 years). Ten patients (6.8%) had associated testicular ischemia (age 3 weeks to 6 months, average 9 weeks) and showed a statistically significant increase in ipsilateral testicular size compared to the contralateral testicle (P = 0.012). Patients without testicular ischemia did not show a significant difference in testicular size, regardless of patient age. An incarcerated inguinal hernia should be considered as a cause of acute testicular ischemia in infants younger than 6 months of age.

  15. Zinc translocation accelerates infarction after mild transient focal ischemia.

    Science.gov (United States)

    Lee, J-M; Zipfel, G J; Park, K H; He, Y Y; Hsu, C Y; Choi, D W

    2002-01-01

    Excess release of chelatable zinc (Zn(2+)) from central synaptic vesicles may contribute to the pathogenesis of selective neuronal cell death following transient forebrain ischemia, but a role in neurodegeneration after focal ischemia has not been defined. Adult male Long-Evans rats subjected to middle cerebral artery occlusion (MCAO) for 30 min followed by reperfusion developed delayed cerebral infarction reaching completion 3 days after the insult. One day after the insult, many degenerating cerebral neurons exhibited increased intracellular Zn(2+), and some labeled with the antibody against activated caspase-3. I.c.v. administration of the Zn(2+) chelator, EDTA saturated with equimolar Ca(2+) (CaEDTA), 15 min prior to ischemia attenuated subsequent Zn(2+) translocation into cortical neurons, and reduced infarct volume measured 3 days after ischemia. Although the protective effect of CaEDTA at this endpoint was substantial (about 70% infarct reduction), it was lost when insult severity was increased (from 30 to 60 min MCAO), or when infarct volume was measured at a much later time point (14 days instead of 3 days after ischemia). These data suggest that toxic Zn(2+) translocation, from presynaptic terminals to post-synaptic cell bodies, may accelerate the development of cerebral infarction following mild transient focal ischemia.

  16. Quantification of the total Na,K-ATPase concentration in atria and ventricles from mammalian species by measuring 3H-ouabain binding to intact myocardial samples. Stability to short term ischemia reperfusion

    DEFF Research Database (Denmark)

    Schmidt, Thomas A; Svendsen, J H; Haunsø, S

    1990-01-01

    ,K-ATPase may be less than 1% due to loss during purification. A higher Na,K-ATPase concentration is found in small animals than in large animals. A relationship between higher concentration of Na,K-ATPase and larger pressure work in ventricles compared to atria is suggested. Myocardial 3H-ouabain binding sites...... were found to be stable for 20 min of ischemia, followed by 1 h of reperfusion, supporting the concept that myocyte injury induced by short term ischemia may be reversible and that reperfusion may result in normalization....

  17. Quantification of the total Na,K-ATPase concentration in atria and ventricles from mammalian species by measuring 3H-ouabain binding to intact myocardial samples. Stability to short term ischemia reperfusion

    DEFF Research Database (Denmark)

    Schmidt, T A; Svendsen, Jesper Hastrup; Haunsø, S

    2011-01-01

    ,K-ATPase may be less than 1% due to loss during purification. A higher Na,K-ATPase concentration is found in small animals than in large animals. A relationship between higher concentration of Na,K-ATPase and larger pressure work in ventricles compared to atria is suggested. Myocardial 3H-ouabain binding sites...... were found to be stable for 20 min of ischemia, followed by 1 h of reperfusion, supporting the concept that myocyte injury induced by short term ischemia may be reversible and that reperfusion may result in normalization....

  18. Drug-Induced Hypothermia as Beneficial Treatment before and after Cerebral Ischemia

    DEFF Research Database (Denmark)

    Johansen, Flemming F; Hasseldam, Henrik; Rasmussen, Rune Skovgaard

    2014-01-01

    Objectives: Hypothermia is still unproven as beneficial treatment in human stroke, although in animal models, conditioning the brain with hypothermia has induced tolerance to insults. Here, we delineate the feasibility of drug-induced mild hypothermia in reducing ischemic brain damage when...... conditioning before (preconditioning) and after (postconditioning) experimental stroke. Methods: Hypothermia was induced in rats with a bolus of 6 mg/kg talipexole followed by 20 h continuous talipexole infusion of 6 mg/kg in total. Controls received similar treatment with saline. The core body temperature...... was continuously monitored. In preconditioning, hypothermia was terminated before either reversible occlusion of the middle cerebral artery (MCAO) for 60 min or global ischemia for 10 min with 2-vessel occlusion and hypotension. In postconditioning, rats experienced 60 min of MCAO before hypothermia was induced...

  19. Detection of myocardial ischemia of hypertrophic cardiomyopathy with gated 99Tcm-MIBI myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Jia Peng; Guo Wanhua; Du Minghua; Gao Ling

    2010-01-01

    Objective: To evaluate the value of gated 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging in detection of myocardial ischemia in hypertrophic cardiomyopathy. Methods: Sixty-nine patients with clinically proven hypertrophic cardiomyopathy were divided into 2 groups using coronary angiogram as 'gold standard': positive group (n=19, narrowing ≥ 50%) and negative group (n=50, narrowing 99 Tc m -MIBI myocardial perfusion imaging was performed and positive in all 69 patients (41 males, 28 females, aged 35-75 years). Comparative analysis between the two groups was carried out using t-test. Results: In the positive group, reversible and irreversible perfusion defects were detected in 9 and 10 patients, respectively. Left ventricular ejection fraction (LVEF) increased to (69.1 ± 2.8)% in 8 patients and decreased to (42.8 ± 2.1)% in 11 patients. In the negative group, reversible and irreversible perfusion defects were found in 37 and 13 patients, respectively. LVEF increased to (70.8 ± 4.0)% in 38 patients and decreased to (48.9 ± 2.7)% in 12 patients. The values of ischemic area, severity and extent of perfusion defect, and LVEF were significantly different between the two groups (t=9.28, 16.51, 2.65; P 99 Tc m -MIBI myocardial perfusion imaging is valuable in assessing patients with hypertrophic cardiomyopathy. Detection for the presence or absence of coexisting coronary artery disease and myocardial ischemia has an important prognostic indication and management indication for these patients. (authors)

  20. The Medial Dorsal Thalamic Nucleus and the Medial Prefrontal Cortex of the Rat Function Together to Support Associative Recognition and Recency but Not Item Recognition

    Science.gov (United States)

    Cross, Laura; Brown, Malcolm W.; Aggleton, John P.; Warburton, E. Clea

    2013-01-01

    In humans recognition memory deficits, a typical feature of diencephalic amnesia, have been tentatively linked to mediodorsal thalamic nucleus (MD) damage. Animal studies have occasionally investigated the role of the MD in single-item recognition, but have not systematically analyzed its involvement in other recognition memory processes. In…

  1. The Activity of Thalamic Nucleus Reuniens Is Critical for Memory Retrieval, but Not Essential for the Early Phase of "Off-Line" Consolidation

    Science.gov (United States)

    Mei, Hao; Logothetis, Nikos K.; Eschenko, Oxana

    2018-01-01

    Spatial navigation depends on the hippocampal function, but also requires bidirectional interactions between the hippocampus (HPC) and the prefrontal cortex (PFC). The cross-regional communication is typically regulated by critical nodes of a distributed brain network. The thalamic nucleus reuniens (RE) is reciprocally connected to both HPC and…

  2. The role of the nucleus basalis of Meynert and reticular thalamic nucleus in pathogenesis of genetically determined absence epilepsy in rats : A lesion study

    NARCIS (Netherlands)

    Berdiev, R. K.; Chepurnov, S. A.; Veening, J. G.; Chepurnova, N. E.; van Luiftelaar, G.

    2007-01-01

    The role of cholinergic nucleus basalis (of Meynert) and the reticular thalamic nucleus in mechanisms of the generation spontaneous spike-and-wave discharges (SWDs) was investigated in the WAG/Rij rat model of absence epilepsy. Selective lesions were affected by local unilateral intraparenchymal

  3. Different expressions of high voltage-activated Ca2+ channel types in the rostral reticular thalamic nucleus of the absence epileptic WAG/Rij rat.

    NARCIS (Netherlands)

    Bovenkamp-Janssen, M.C. van de; Scheenen, W.J.J.M.; Kuijpers-Kwant, F.J.; Kozicz, L.T.; Veening, J.G.; Luijtelaar, E.L.J.M. van; McEnery, M.W.; Roubos, E.W.

    2004-01-01

    In the WAG/Rij rat, a model for human absence epilepsy, spike-wave discharges (SWD) and absence epileptic behavior develop after the age of 3 months. The rostral part of the reticular thalamic nucleus (rRTN) is involved in SWD. Ca(2+) channels play a central role in the initiation and maintenance of

  4. VEGF attenuated increase of outward delayed-rectifier potassium currents in hippocampal neurons induced by focal ischemia via PI3-K pathway.

    Science.gov (United States)

    Wu, K W; Yang, P; Li, S S; Liu, C W; Sun, F Y

    2015-07-09

    We recently indicated that the vascular endothelial growth factor (VEGF) protects neurons against hypoxic death via enhancement of tyrosine phosphorylation of Kv1.2, an isoform of the delayed-rectifier potassium channels through activation of the phosphatidylinositol 3-kinase (PI3-K) signaling pathway. The present study investigated whether VEGF could attenuate ischemia-induced increase of the potassium currents in the hippocampal pyramidal neurons of rats after ischemic injury. Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion (MCAO) to induce brain ischemia. The whole-cell patch-clamp technique was used to record the potassium currents of hippocampal neurons in brain slices from the ischemically injured brains of the rats 24h after MCAO. We detected that transient MCAO caused a significant increase of voltage-gated potassium currents (Kv) and outward delayed-rectifier potassium currents (IK), but not outward transient potassium currents (IA), in the ipsilateral hippocampus compared with the sham. Moreover, we found that VEGF could acutely, reversibly and voltage-dependently inhibit the ischemia-induced IK increase. This inhibitory effect of VEGF could be completely abolished by wortmannin, an inhibitor of PI3-K. Our data indicate that VEGF attenuates the ischemia-induced increase of IK via activation of the PI3-K signaling pathway. Published by Elsevier Ltd.

  5. An algebra of reversible computation.

    Science.gov (United States)

    Wang, Yong

    2016-01-01

    We design an axiomatization for reversible computation called reversible ACP (RACP). It has four extendible modules: basic reversible processes algebra, algebra of reversible communicating processes, recursion and abstraction. Just like process algebra ACP in classical computing, RACP can be treated as an axiomatization foundation for reversible computation.

  6. Outcomes of lower extremity bypass performed for acute limb ischemia.

    Science.gov (United States)

    Baril, Donald T; Patel, Virendra I; Judelson, Dejah R; Goodney, Philip P; McPhee, James T; Hevelone, Nathanael D; Cronenwett, Jack L; Schanzer, Andres

    2013-10-01

    Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function

  7. Treatment of Digital Ischemia with Liposomal Bupivacaine

    Directory of Open Access Journals (Sweden)

    José Raul Soberón

    2014-01-01

    Full Text Available Objective. This report describes a case in which the off-label use of liposomal bupivacaine (Exparel in a peripheral nerve block resulted in marked improvement of a patient’s vasoocclusive symptoms. The vasodilating and analgesic properties of liposomal bupivacaine in patients with ischemic symptoms are unknown, but our clinical experience suggests a role in the management of patients suffering from vasoocclusive disease. Case Report. A 45-year-old African American female was admitted to the hospital with severe digital ischemic pain. She was not a candidate for any vascular surgical or procedural interventions. Two continuous supraclavicular nerve blocks were placed with modest clinical improvement. These effects were also short-lived, with the benefits resolving after the discontinuation of the peripheral nerve blocks. She continued to report severe pain and was on multiple anticoagulant medications, so a decision was made to perform an axillary nerve block using liposomal bupivacaine (Exparel given the compressibility of the site as well as the superficial nature of the target structures. Conclusions. This case report describes the successful off-label usage of liposomal bupivacaine (Exparel in a patient with digital ischemia. Liposomal bupivacaine (Exparel is currently FDA approved only for wound infiltration use at this time.

  8. Temporary intestinal ischemia for radiation protection

    International Nuclear Information System (INIS)

    Lote, K.

    1983-01-01

    The most important determinant of cellular radiosensivity is the tissue oxygen content at the time of irradiation. The purpose of the present experimental work was to assess a new iscemia-inducing method in order to reduce normal tissue radiation damage during radiotherapy. Temporary ischemia was induced in a cat small intestine by degraded starch microspheres. Regional arterial and tissue blod flow immediately fell by 85% with subsequent normalization within 26 minutes after microsphere injection. No tendency of small vessel thrombosis caused by starch sphere embolization in combination with previous or current intestinal irradiation was detected. Starch sphere remenants were rapidly engulfed by, and persisted within tissue macrophages for 14 days without causing intestinal inflammatory reactions. In vitro studies showed that human platelets neither adhered to nor were aggregated by starch microspheres. The new method, wich occlude arteriolar vessels distal to the mesentric arterial arcades and thus largely excludes collateral blood flow, seems suited to provide effictive and selective feline small intestinal hypoxic radiation protection. This conclusion may also be valid in man

  9. Usefulness of percutaneous transluminal coronary angioplasty in silent myocardial ischemia

    International Nuclear Information System (INIS)

    Hou, Mami

    1996-01-01

    The usefulness of percutaneous transluminal coronary angioplasty (PTCA) was assessed in patients with exercise-induced asymptomatic myocardial ischemia (silent ischemia) and compared with exercise-induced symptomatic myocardial ischemia (symptomatic ischemia). Patients with single vessel coronary artery disease (51 with angina pectoris, 40 with old myocardial infarction) and evidence of stress-induced ischemia on thallium-201 single photon emission computed tomography (SPECT) underwent successful PTCA. Thirty-seven percent of angina patients and 60% of infarction patients showed asymptomatic exercise-induced ischemia. There was no significant difference in population characteristics between silent and symptomatic patients. Patients with silent angina had significantly higher percentage thallium uptake and washout rate than symptomatic patients. After PTCA, both percentage diameter stenosis and percentage thallium uptake were improved in all patients with angina irrespective of the presence or absence of symptoms. There were no significant differences in percentage thallium uptake and washout rate between patients with silent and symptomatic infarction. After PTCA, percentage diameter stenosis, percentage thallium uptake, and washout rate improved in all infarction patients irrespective of the symptoms. Zero percent of silent angina patients, 12% of symptomatic angina patients, 12% of silent infarction patients, 19% of symptomatic infarction patients had cardiac events during about 4.5 years after PTCA. The incidence of cardiac events did not significantly differ in any patient group. PTCA improved myocardial perfusion in all patients, and the incidence of cardiac events did not differ between the silent and symptomatic groups. Revascularization with PTCA is suitable for patients with silent as well as symptomatic ischemia. (author)

  10. Sex reversal in vertebrates

    OpenAIRE

    2016-01-01

    This special topic issue of Sexual Development gives an overview of sex reversal in vertebrates, from fishes naturally changing their sex, to rodents escaping the mammalian SRY-determining system. It offers eight up-to-date reviews on specific subjects in sex reversal, considering fishes, amphibians, reptiles, birds, marsupials, and placental mammals, including humans. The broad scope of represented animals makes this ideal for students and researchers, especially those interested in the...

  11. Prediction of cerebral ischemia due to cerebral vasospasm in SAH using SPECT and 123I-IMP with acetazolamide test

    International Nuclear Information System (INIS)

    Nakagawara, Jyoji; Wada, Keiji; Takeda, Rihei; Usami, Takashi; Hashimoto, Ikuo; Shimazaki, Mitsuteru; Tanaka, Chiharu; Nakamura, Jun-ichi; Suematsu, Katsumi.

    1989-01-01

    To investigate the possibility of predicting cerebral ischemia due to cerebral vasospasm in subarachnoid hemorrhage (SAH), serial evaluation of the cerebral vasodilatory capacity by the acetazolamide test was conducted, using single photon emission computed tomography (SPECT) and N-isopropyl 123 I-p-iodoamphetamine (IMP), in 17 patients with cerebral vasospasm following early surgery for ruptured aneurysms. The degree of vasospasm measured on the angiograms was classified into the following three types; mild degree (25%>stenosis), moderate degree (25∼50% stenosis), and severe degree(50%reversible ischemia, a marked limitation of cerebral vasodilatory capacity was noted between the 7th and 15th day, and a delayed recovery of cerebral vasodilatory capacity was observed. This reversibility of cerebral vasodilatory capacity in patients with cerebral vasospasm suggests that a local decrease of purfusion pressure due to cerebral vasospasm causes compensatory vasodilation of intraparenchymal arteries and the vasodilatory reaction to acetazolamide was limited until the release of the cerebral vasospasm. Therefore, assessment of cerebral vasodilatory capacity in SAH by the acetazolamide test might predict the appearance and continuation of potential ischemia of the brain caused by the reduction of perfusion pressure due to cerebral vasospasm. (J.P.N.)

  12. PARP Inhibition Attenuates Histopathological Lesion in Ischemia/Reperfusion Renal Mouse Model after Cold Prolonged Ischemia

    Directory of Open Access Journals (Sweden)

    Raimundo M. G. del Moral

    2013-01-01

    Full Text Available We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN and other renal lesions related to prolonged cold ischemia/reperfusion (IR in kidneys preserved at 4°C in University of Wisconsin (UW solution. Material and Methods. We used 30 male Parp1+/+ wild-type and 15 male Parp10/0 knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinylbutoxyl]-1(2H-isoquinolinone (DPQ at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ. We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp10/0 knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation.

  13. Exercise-induced silent myocardial ischemia: Evaluation by thallium-201 emission computed tomography

    International Nuclear Information System (INIS)

    Kurata, C.; Sakata, K.; Taguchi, T.; Kobayashi, A.; Yamazaki, N.

    1990-01-01

    Factors associated with silent myocardial ischemia (SMI) during exercise testing were studied by means of thallium-201 emission computed tomography (ECT) in 471 patients. Coronary angiography was done in 290, of whom 167 were found to have significant coronary artery disease (CAD). Exercise-induced ischemia and its severity were defined with ECT. During exercise 108 (62%) of 173 patients with ischemia and 57 (50%) of 115 with ischemia and angiographically documented CAD had no chest pain. One third of the patients showed an inconsistency between scintigraphic ischemia and ischemia ST depression. Age, sex, prior myocardial infarction, and diabetes mellitus were not related to SMI. Patients with SMI had less severe ischemia despite a higher peak double product compared to those with painful ischemia. Among 91 with prior myocardial infarction and exercise-induced ischemia, 51 with periinfarction ischemia had a higher frequency of SMI than did 14 with ischemia remote from the prior infarct zone despite similarities in the severity of ischemia. In conclusion, factors localized within ischemic myocardium such as less severe ischemia or adjacency to a prior infarct made SMI more prevalent

  14. Myocutaneous revascularization following graded ischemia in lean and obese mice

    Directory of Open Access Journals (Sweden)

    Clark RM

    2016-09-01

    Full Text Available Ross M Clark,1 Brittany Coffman,2 Paul G McGuire,3 Thomas R Howdieshell1,3 1Department of Surgery, 2Department of Pathology, 3Department of Cell Biology and Vascular Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA Background: Murine models of diabetes and obesity have provided insight into the pathogenesis of impaired epithelialization of excisional skin wounds. However, knowledge of postischemic myocutaneous revascularization in these models is limited. Materials and methods: A myocutaneous flap was created on the dorsum of wild type (C57BL/6, genetically obese and diabetic (ob/ob, db/db, complementary heterozygous (ob+/ob− , db+/db−, and diet-induced obese (DIO mice (n=48 total; five operative mice per strain and three unoperated mice per strain as controls. Flap perfusion was documented by laser speckle contrast imaging. Local gene expression in control and postoperative flap tissue specimens was determined by quantitative reverse transcription polymerase chain reaction (RT-PCR. Image analysis of immunochemically stained histologic sections confirmed microvascular density and macrophage presence. Results: Day 10 planimetric analysis revealed mean flap surface area necrosis values of 10.8%, 12.9%, 9.9%, 0.4%, 1.4%, and 23.0% for wild type, db+/db−, ob+/ob−, db/db, ob/ob, and DIO flaps, respectively. Over 10 days, laser speckle imaging documented increased perfusion at all time points with revascularization to supranormal perfusion in db/db and ob/ob flaps. In contrast, wild type, heterozygous, and DIO flaps displayed expected graded ischemia with failure of perfusion to return to baseline values. RT-PCR demonstrated statistically significant differences in angiogenic gene expression between lean and obese mice at baseline (unoperated and at day 10. Conclusion: Unexpected increased baseline skin perfusion and augmented myocutaneous revascularization accompanied by a control proangiogenic transcriptional

  15. Bilingual language processing after a lesion in the left thalamic and temporal regions. A case report with early childhood onset

    International Nuclear Information System (INIS)

    van Lieshout, P.; Renier, W.; Eling, P.; de Bot, K.; Slis, I.

    1990-01-01

    This case study concerns an 18-year-old bilingual girl who suffered a radiation lesion in the left (dominant) thalamic and temporal region when she was 4 years old. Language and memory assessment revealed deficits in auditory short-term memory, auditory word comprehension, nonword repetition, syntactic processing, word fluency, and confrontation naming tasks. Both languages (English and Dutch) were found to be affected in a similar manner, despite the fact that one language (English) was acquired before and the other (Dutch) after the period of lesion onset. Most of the deficits appear to be related to verbal (short-term) memory dysfunction. Several hypotheses of subcortical involvement in memory processes are discussed with reference to existing theories in this area

  16. On the genesis of spike-wave oscillations in a mean-field model of human thalamic and corticothalamic dynamics

    International Nuclear Information System (INIS)

    Rodrigues, Serafim; Terry, John R.; Breakspear, Michael

    2006-01-01

    In this Letter, the genesis of spike-wave activity-a hallmark of many generalized epileptic seizures-is investigated in a reduced mean-field model of human neural activity. Drawing upon brain modelling and dynamical systems theory, we demonstrate that the thalamic circuitry of the system is crucial for the generation of these abnormal rhythms, observing that the combination of inhibition from reticular nuclei and excitation from the cortical signal, interplay to generate the spike-wave oscillation. The mechanism revealed provides an explanation of why approaches based on linear stability and Heaviside approximations to the activation function have failed to explain the phenomena of spike-wave behaviour in mean-field models. A mathematical understanding of this transition is a crucial step towards relating spiking network models and mean-field approaches to human brain modelling

  17. An experimental approach towards the development of an in vitro cortical-thalamic co-culture model.

    Science.gov (United States)

    Kanagasabapathi, Thirukumaran T; Massobrio, Paolo; Tedesco, Mariateresa; Martinoia, Sergio; Wadman, Wytse J; Decré, Michel M J

    2011-01-01

    In this paper, we propose an experimental approach to develop an in vitro dissociated cortical-thalamic co-culture model using a dual compartment neurofluidic device. The device has two compartments separated by 10 μm wide and 3 μm high microchannels. The microchannels provide a physical isolation of neurons allowing only neurites to grow between the compartments. Long-term viable co-culture was maintained in the compartmented device, neurite growth through the microchannels was verified using immunofluorescence staining, and electrophysiological recordings from the co-culture system was investigated. Preliminary analysis of spontaneous activities from the co-culture shows a distinctively different firing pattern associated with cultures of individual cell types and further analysis is proposed for a deeper understanding of the dynamics involved in the network connectivity in such a co-culture system.

  18. On thermodynamic and microscopic reversibility

    International Nuclear Information System (INIS)

    Crooks, Gavin E

    2011-01-01

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa

  19. External pallidal stimulation improves parkinsonian motor signs and modulates neuronal activity throughout the basal ganglia thalamic network.

    Science.gov (United States)

    Vitek, Jerrold L; Zhang, Jianyu; Hashimoto, Takao; Russo, Gary S; Baker, Kenneth B

    2012-01-01

    Deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) and the subthalamic nucleus (STN) are effective for the treatment of advanced Parkinson's disease (PD). We have shown previously that DBS of the external segment of the globus pallidus (GPe) is associated with improvements in parkinsonian motor signs; however, the mechanism of this effect is not known. In this study, we extend our findings on the effect of STN and GPi DBS on neuronal activity in the basal ganglia thalamic network to include GPe DBS using the 1-methyl-4-phenyl-1.2.3.6-tetrahydropyridine (MPTP) monkey model. Stimulation parameters that improved bradykinesia were associated with changes in the pattern and mean discharge rate of neuronal activity in the GPi, STN, and the pallidal [ventralis lateralis pars oralis (VLo) and ventralis anterior (VA)] and cerebellar [ventralis lateralis posterior pars oralis (VPLo)] receiving areas of the motor thalamus. Population post-stimulation time histograms revealed a complex pattern of stimulation-related inhibition and excitation for the GPi and VA/VLo, with a more consistent pattern of inhibition in STN and excitation in VPLo. Mean discharge rate was reduced in the GPi and STN and increased in the VPLo. Effective GPe DBS also reduced bursting in the STN and GPi. These data support the hypothesis that therapeutic DBS activates output from the stimulated structure and changes the temporal pattern of neuronal activity throughout the basal ganglia thalamic network and provide further support for GPe as a potential therapeutic target for DBS in the treatment of PD. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Control of Somatosensory Cortical Processing by Thalamic Posterior Medial Nucleus: A New Role of Thalamus in Cortical Function.

    Directory of Open Access Journals (Sweden)

    Carlos Castejon

    Full Text Available Current knowledge of thalamocortical interaction comes mainly from studying lemniscal thalamic systems. Less is known about paralemniscal thalamic nuclei function. In the vibrissae system, the posterior medial nucleus (POm is the corresponding paralemniscal nucleus. POm neurons project to L1 and L5A of the primary somatosensory cortex (S1 in the rat brain. It is known that L1 modifies sensory-evoked responses through control of intracortical excitability suggesting that L1 exerts an influence on whisker responses. Therefore, thalamocortical pathways targeting L1 could modulate cortical firing. Here, using a combination of electrophysiology and pharmacology in vivo, we have sought to determine how POm influences cortical processing. In our experiments, single unit recordings performed in urethane-anesthetized rats showed that POm imposes precise control on the magnitude and duration of supra- and infragranular barrel cortex whisker responses. Our findings demonstrated that L1 inputs from POm imposed a time and intensity dependent regulation on cortical sensory processing. Moreover, we found that blocking L1 GABAergic inhibition or blocking P/Q-type Ca2+ channels in L1 prevents POm adjustment of whisker responses in the barrel cortex. Additionally, we found that POm was also controlling the sensory processing in S2 and this regulation was modulated by corticofugal activity from L5 in S1. Taken together, our data demonstrate the determinant role exerted by the POm in the adjustment of somatosensory cortical processing and in the regulation of cortical processing between S1 and S2. We propose that this adjustment could be a thalamocortical gain regulation mechanism also present in the processing of information between cortical areas.

  1. Fear conditioning leads to alteration in specific genes expression in cortical and thalamic neurons that project to the lateral amygdala.

    Science.gov (United States)

    Katz, Ira K; Lamprecht, Raphael

    2015-02-01

    RNA transcription is needed for memory formation. However, the ability to identify genes whose expression is altered by learning is greatly impaired because of methodological difficulties in profiling gene expression in specific neurons involved in memory formation. Here, we report a novel approach to monitor the expression of genes after learning in neurons in specific brain pathways needed for memory formation. In this study, we aimed to monitor gene expression after fear learning. We retrogradely labeled discrete thalamic neurons that project to the lateral amygdala (LA) of rats. The labeled neurons were dissected, using laser microdissection microscopy, after fear conditioning learning or unpaired training. The RNAs from the dissected neurons were subjected to microarray analysis. The levels of selected RNAs detected by the microarray analysis to be altered by fear conditioning were also assessed by nanostring analysis. We observed that the expression of genes involved in the regulation of translation, maturation and degradation of proteins was increased 6 h after fear conditioning compared to unpaired or naïve trained rats. These genes were not expressed 24 h after training or in cortical neurons that project to the LA. The expression of genes involved in transcription regulation and neuronal development was altered after fear conditioning learning in the cortical-LA pathway. The present study provides key information on the identity of genes expressed in discrete thalamic and cortical neurons that project to the LA after fear conditioning. Such an approach could also serve to identify gene products as targets for the development of a new generation of therapeutic agents that could be aimed to functionally identified brain circuits to treat memory-related disorders. © 2014 International Society for Neurochemistry.

  2. Myocardial metabolic abnormalities in hypertrophic cardiomyopathy assessed by iodine-123-labeled beta-methyl-branched fatty acid myocardial scintigraphy and its relation to exercise-induced ischemia

    International Nuclear Information System (INIS)

    Matsuo, Shinro; Nakamura, Yasuyuki; Takahashi, Masayuki; Mitsunami, Kenichi; Kinoshita, Masahiko

    1998-01-01

    Reversible thallium-201 ( 201 Tl) abnormalities during exercise stress have been used as markers of myocardial ischemia in hypertrophic cardiomyopathy (HCM) and are most likely to identify relatively underperfused myocardium. Although metabolic abnormalities in HCM were reported, the relationship between impaired energy metabolism and exercise-induced ischemia has not been fully elucidated as yet. To assess the relationship between myocardial perfusion abnormalities and fatty acid metabolic abnormalities, 28 patients with HCM underwent exercise 201 Tl and rest 123 I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP) scintigraphy. Perfusion abnormalities were observed by exercise 201 Tl in 19/28 patients with HCM. 123 I-BMIPP uptake was decreased compared with delayed 201 Tl in 106/364 (29%) of the total myocardial segments (p 123 I-BMIPP and 201 Tl was observed more often in the 49/75 (65%) segments with reversible exercise 201 Tl defects (p 123 I-BMIPP and 201 Tl suggests that myocardial ischemia may play an important role in metabolic abnormalities in HCM. (author)

  3. Gene expression in cerebral ischemia: a new approach for neuroprotection.

    Science.gov (United States)

    Millán, Mónica; Arenillas, Juan

    2006-01-01

    Cerebral ischemia is one of the strongest stimuli for gene induction in the brain. Hundreds of genes have been found to be induced by brain ischemia. Many genes are involved in neurodestructive functions such as excitotoxicity, inflammatory response and neuronal apoptosis. However, cerebral ischemia is also a powerful reformatting and reprogramming stimulus for the brain through neuroprotective gene expression. Several genes may participate in both cellular responses. Thus, isolation of candidate genes for neuroprotection strategies and interpretation of expression changes have been proven difficult. Nevertheless, many studies are being carried out to improve the knowledge of the gene activation and protein expression following ischemic stroke, as well as in the development of new therapies that modify biochemical, molecular and genetic changes underlying cerebral ischemia. Owing to the complexity of the process involving numerous critical genes expressed differentially in time, space and concentration, ongoing therapeutic efforts should be based on multiple interventions at different levels. By modification of the acute gene expression induced by ischemia or the apoptotic gene program, gene therapy is a promising treatment but is still in a very experimental phase. Some hurdles will have to be overcome before these therapies can be introduced into human clinical stroke trials. Copyright 2006 S. Karger AG, Basel.

  4. Metabolomic profiling to characterize acute intestinal ischemia/reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Rachel G Khadaroo

    Full Text Available Sepsis and septic shock are the leading causes of death in critically ill patients. Acute intestinal ischemia/reperfusion (AII/R is an adaptive response to shock. The high mortality rate from AII/R is due to the severity of the disease and, more importantly, the failure of timely diagnosis. The objective of this investigation is to use nuclear magnetic resonance (NMR analysis to characterize urine metabolomic profile of AII/R injury in a mouse model. Animals were exposed to sham, early (30 min or late (60 min acute intestinal ischemia by complete occlusion of the superior mesenteric artery, followed by 2 hrs of reperfusion. Urine was collected and analyzed by NMR spectroscopy. Urinary metabolite concentrations demonstrated that different profiles could be delineated based on the duration of the intestinal ischemia. Metabolites such as allantoin, creatinine, proline, and methylamine could be predictive of AII/R injury. Lactate, currently used for clinical diagnosis, was found not to significantly contribute to the classification model for either early or late ischemia. This study demonstrates that patterns of changes in urinary metabolites are effective at distinguishing AII/R progression in an animal model. This is a proof-of-concept study to further support examination of metabolites in the clinical diagnosis of intestinal ischemia reperfusion injury in patients. The discovery of a fingerprint metabolite profile of AII/R will be a major advancement in the diagnosis, treatment, and prevention of systemic injury in critically ill patients.

  5. Normobaric Oxygen Therapy for Scleral Ischemia or Melt

    Directory of Open Access Journals (Sweden)

    Farideh Sharifipour

    2012-01-01

    Full Text Available Purpose: To investigate the efficacy of normobaric oxygen (NBO therapy for treatment of scleral ischemia or melt. Methods: This prospective interventional case series includes 9 eyes of 8 patients with scleral ischemia or melt of diverse etiologies. Following the failure of conventional medical and/or surgical therapy to improve ischemia or upon clinical deterioration, NBO was initiated. All patients received 100% NBO at flow rate of 10 liters/minute by face mask for 1 hour, twice daily until complete vascularization of ischemic areas. Main outcome measures were improvement of scleral ischemia and healing of conjunctival epithelial defects. Results: NBO therapy led to epithelialization and vascularization of the ischemic sclera in all eyes; the repair process began 3-4 days after NBO had been initiated and was completed in 18.1±4.7 (range, 10-25 days. All patients remained stable over a 9-month follow-up period. Conclusion: NBO therapy seems effective for treatment of scleral ischemia or melt, and hence can be considered as a non-invasive alternative to surgical intervention in these conditions.

  6. Mitochondrial Bioenergetics During Ischemia and Reperfusion.

    Science.gov (United States)

    Consolini, Alicia E; Ragone, María I; Bonazzola, Patricia; Colareda, Germán A

    2017-01-01

    During ischemia and reperfusion (I/R) mitochondria suffer a deficiency to supply the cardiomyocyte with chemical energy, but also contribute to the cytosolic ionic alterations especially of Ca 2+ . Their free calcium concentration ([Ca 2+ ]m) mainly depends on mitochondrial entrance through the uniporter (UCam) and extrusion in exchange with Na + (mNCX) driven by the electrochemical gradient (ΔΨm). Cardiac energetic is frequently estimated by the oxygen consumption, which determines metabolism coupled to ATP production and to the maintaining of ΔΨm. Nevertheless, a better estimation of heart energy consumption is the total heat release associated to ATP hydrolysis, metabolism, and binding reactions, which is measurable either in the presence or the absence of oxygenation or perfusion. Consequently, a mechano-calorimetrical approach on isolated hearts gives a tool to evaluate muscle economy. The mitochondrial role during I/R depends on the injury degree. We investigated the role of the mitochondrial Ca 2+ transporters in the energetic of hearts stunned by a model of no-flow I/R in rat hearts. This chapter explores an integrated view of previous and new results which give evidences to the mitochondrial role in cardiac stunning by ischemia o hypoxia, and the influence of thyroid alterations and cardioprotective strategies, such as cardioplegic solutions (high K-low Ca, pyruvate) and the phytoestrogen genistein in both sex. Rat ventricles were perfused in a flow-calorimeter at either 30 °C or 37 °C to continuously measure the left ventricular pressure (LVP) and total heat rate (Ht). A pharmacological treatment was done before exposing to no-flow I and R. The post-ischemic contractile (PICR as %) and energetical (Ht) recovery and muscle economy (Eco: P/Ht) were determined during stunning. The functional interaction between mitochondria (Mit) and sarcoplasmic reticulum (SR) was evaluated with selective mitochondrial inhibitors in hearts reperfused with Krebs-10 m

  7. Local intravascular coagulation and fibrin deposition on intestinal ischemia-reperfusion in rats

    NARCIS (Netherlands)

    Schoots, Ivo G.; Levi, Marcel; Roossink, E. H. Paulina; Bijlsma, Pieter B.; van Gulik, Thomas M.

    2003-01-01

    Background. This study investigates intravascular coagulation and thrombotic obstruction in the splanchnic vasculature after intestinal ischemia in relation to epithelial integrity and function. Methods. Intestinal ischemia was induced in rats by superior mesenteric artery occlusion for 20 or 40

  8. Cellular infiltrates and injury evaluation in a rat model of warm pulmonary ischemia-reperfusion

    NARCIS (Netherlands)

    Van Putte, BP; Kesecioglu, J; Hendriks, JMH; Persy, VP; van Marck, E; Van Schil, PEY; De Broe, ME

    Introduction Beside lung transplantation, cardiopulmonary bypass, isolated lung perfusion and sleeve resection result in serious pulmonary ischemia - reperfusion injury, clinically known as acute respiratory distress syndrome. Very little is known about cells infiltrating the lung during ischemia -

  9. Retrograde Renal Cooling to Minimize Ischemia

    Directory of Open Access Journals (Sweden)

    Janet L. Colli

    2013-01-01

    Full Text Available Objective: During partial nephrectomy, renal hypothermia has been shown to decrease ischemia induced renal damage which occurs from renal hilar clamping. In this study we investigate the infusion rate required to safely cool the entire renal unit in a porcine model using retrograde irrigation of iced saline via dual-lumen ureteral catheter. Materials and Methods: Renal cortical, renal medullary, bowel and rectal temperatures during retrograde cooling in a laparoscopic porcine model were monitored in six renal units. Iced normal saline was infused at 300 cc/hour, 600 cc/hour, 1000 cc/hour and gravity (800 cc/hour for 600 seconds with and without hilar clamping. Results: Retrograde cooling with hilar clamping provided rapid medullary renal cooling and significant hypothermia of the medulla and cortex at infusion rates ≥ 600 cc/hour. With hilar clamping, cortical temperatures decreased at -0.9° C/min. reaching a threshold temperature of 26.9° C, and medullary temperatures decreased at -0.90 C/min. reaching a temperature of 26.1° C over 600 seconds on average for combined data at infusion rates ≥ 600 cc/hour. The lowest renal temperatures were achieved with gravity infusion. Without renal hilum clamping, retrograde cooling was minimal at all infusion rates. Conclusions: Significant renal cooling by gravity infusion of iced cold saline via a duel lumen catheter with a clamped renal hilum was achieved in a porcine model. Continuous retrograde irrigation with iced saline via a two way ureteral catheter may be an effective method to induce renal hypothermia in patients undergoing robotic assisted and/or laparoscopic partial nephrectomy.

  10. DIAGNOSIS AND THERAPY IN TRANSITORY MYOCARDIAL ISCHEMIA

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    Anica Pavlovic

    2008-01-01

    Full Text Available Cardiac dysfunction occurring within subarachnoid hemorrhage named neurogenic stunned myocardium have great impact on intensive care of patients with SAH. Timely diagnosis and treatment of such condition can provide better haemodynamics of damaged brain. The standard follow-up was performed in 30 patients with SAH during two years at the Clinic of Neurosurgery (2005,2006. Serial electrocardiography, echocardiography, as well as laboratory findings of special biomarkers of left ventricular wall motion abnormalities were performed. All patients were treated with Urapidil, Metoprolol, MgSO4 by cheme and ACE inhibitors. Ninety EKG were analyzed in the study, as well as 16 electrocardiographies. The highest levels of CPK, CK-MB and TnI before and after the therapy were also recoded. EKG showed the signs of ischemia in 9 of 30 patients on 1st day and 7 of 30 patients on 3rd day of the therapy. The highest level of CK-MB was present during the 1st day with mean value of 67,80±1,83 IU/L that decreased on 3rd day of therapy with mean value of 66,8±1,83 IU/L, TnI was positive in 16 cases. It showed statistically significant decrease from 0,29 ng/ml till 0,187 ng/ml and p < 0,01. Myocardial ischaemia has been proven to be a very significant complication in SAH. Appropriate treatment of myocardial ischaemia seems to improve systemic haemodynamics, as well as haemodynamics of the damaged brain.

  11. Cerebral hypoxia and ischemia in preterm infants

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    Alberto Ravarino

    2014-06-01

    Full Text Available Premature birth is a major public health issue internationally affecting 13 million babies worldwide. Hypoxia and ischemia is probably the commonest type of acquired brain damage in preterm infants. The clinical manifestations of hypoxic-ischemic injury in survivors of premature birth include a spectrum of cerebral palsy and intellectual disabilities. Until recently, the extensive brain abnormalities in preterm neonates appeared to be related mostly to destructive processes that lead to substantial deletion of neurons, axons, and glia from necrotic lesions in the developing brain. Advances in neonatal care coincide with a growing body of evidence that the preterm gray and white matter frequently sustain less severe insults, where tissue destruction is the minor component. Periventricular leukomalacia (PVL is the major form of white matter injury and consists classically of focal necrotic lesions, with subsequent cyst formation, and a less severe but more diffuse injury to cerebral white mater, with prominent astrogliosis and microgliosis but without overt necrosis. With PVL a concomitant injury occurs to subplate neurons, located in the subcortical white matter. Severe hypoxic-ischemic insults that trigger significant white matter necrosis are accompanied by neuronal degeneration in cerebral gray and white matter. This review aims to illustrate signs of cerebral embryology of the second half of fetal life and correlate hypoxic-ischemic brain injury in the premature infant. This should help us better understand the symptoms early and late and facilitate new therapeutic strategies. Proceedings of the International Course on Perinatal Pathology (part of the 10th International Workshop on Neonatology · October 22nd-25th, 2014 · Cagliari (Italy · October 25th, 2014 · The role of the clinical pathological dialogue in problem solving Guest Editors: Gavino Faa, Vassilios Fanos, Peter Van Eyken

  12. TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN PATIENTS WITH CEREBRAL ISCHEMIA

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    Kavian Ghandehari

    2010-12-01

    Full Text Available Abstract INTRODUCTION: Transesophageal echocardiography (TEE is superior to Transthoracic echocardiography (TTE in detection of atrial septal defects and aneurysm, aortic atheroma, left atrial thrombus and mitral valve abnormalities. TEE is indicated in young adults with cryptogenic ischemic stroke who are suspected of having cardioembolic mechanism despite non-diagnostic TTE. METHODS: A prospective clinical study was conducted in patients with ischemic stroke or TIA who had TTE done in Ghaem hospital, Mashhad during 2006-2007. Ischemic cerebrovascular events were detected by stroke neurologist. TEE was performed with VIPI3/GE device, USA and a 7 MHz transesophageal probe by an echocardiologist. Patients who did not have TTE before TEE were excluded. Comparison of TEE to TTE results was performed by the echocardiologist and stroke neurologist in each patient. Influence of TEE on therapeutic decisions in each patient was evaluated. RESULTS: Forty-seven patients (20 females, 27 males with a mean age of 42.6±7.3 years were studied. Cardiac and aortic abnormalities were detected in TEE of 35 cases (35/47; 74% with ischemic cerebrovascular events. Cardiac abnormalities of 17 cases (36% were only detectable by TEE. These seventeen cases included 7 patients with PFO, 1 case with ASD, 6 cases with aortic atheroma and 2 patients with clot in the left atrium. Comparing the preventive stroke strategies before and after TEE revealed that it was changed only in two cases (2/47; 4.3% due to performing TEE. These included one patient with a small high-risk PFO and another case with dehicense of mechanical mitral valve. CONCLUSION: TEE revealed cardiac or aortic abnormalities in one-third of the patients with cerebral ischemia and has not been detected by TEE previously. The influence of TEE in therapeutic decisions of patients with ischemic cerebrovascular events is very low.         Keywords: Transesophageal echocardiography, Stroke, Transient Ischemic

  13. Gabapentin reverses central pain sensitization following a collagenase-induced intrathalamic hemorrhage in rats

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    Castel A

    2013-12-01

    Full Text Available Aude Castel, Pascal VachonFaculty of Veterinary Medicine, Department of Veterinary Biomedicine, University of Montreal, Saint-Hyacinthe, QC, CanadaPurpose: The treatment of central neuropathic pain remains amongst the biggest challenges for pain specialists. The main objective of this study was to assess gabapentin (GBP, amitriptyline (AMI, and carbamazepine (CARBA for the treatment of a rodent central neuropathic pain model.Methods: Male Sprague Dawley rats were trained on the rotarod, Hargreaves, Von Frey and acetone behavioral tests, and baseline values were obtained prior to surgery. A stereotaxic injection of either a collagenase solution or saline was made in the right ventral posterolateral thalamic nucleus. The rats were tested on days 2, 4, 8, and 11 postsurgery. They were retested at regular intervals from day 15 to day 25 postsurgery, after oral administration of either the vehicle (n=7 and n=8 rats with intracerebral injections of collagenase and saline, respectively or the different drugs (GBP [60 mg/kg], AMI [10 mg/kg], CARBA [100 mg/kg]; n=8 rats/drug.Results: A significant decrease in the mechanical thresholds and no change in heat threshold were observed in both hind limbs in the collagenase group, as we had previously shown elsewhere. Reversal of the mechanical hypersensitivity was achieved only with GBP (P<0.05. AMI and CARBA, at the dosages used, failed to show any effect on mechanical thresholds. Transient cold allodynia was observed in some collagenase-injected rats but failed to be statistically significant.Conclusion: Intrathalamic hemorrhaging in the ventrolateral thalamic nucleus induced a bilateral mechanical allodynia, which was reversed by GBP but not AMI or CARBA.Keywords: central pain, thalamus, amitriptyline, carbamazepine

  14. Reversible Communicating Processes

    Directory of Open Access Journals (Sweden)

    Geoffrey Brown

    2016-02-01

    Full Text Available Reversible distributed programs have the ability to abort unproductive computation paths and backtrack, while unwinding communication that occurred in the aborted paths. While it is natural to assume that reversibility implies full state recovery (as with traditional roll-back recovery protocols, an interesting alternative is to separate backtracking from local state recovery. For example, such a model could be used to create complex transactions out of nested compensable transactions where a programmer-supplied compensation defines the work required to "unwind" a transaction. Reversible distributed computing has received considerable theoretical attention, but little reduction to practice; the few published implementations of languages supporting reversibility depend upon a high degree of central control. The objective of this paper is to demonstrate that a practical reversible distributed language can be efficiently implemented in a fully distributed manner. We discuss such a language, supporting CSP-style synchronous communication, embedded in Scala. While this language provided the motivation for the work described in this paper, our focus is upon the distributed implementation. In particular, we demonstrate that a "high-level" semantic model can be implemented using a simple point-to-point protocol.

  15. Metabolic Crisis in Severely Head-Injured Patients: Is Ischemia Just the Tip of the Iceberg?

    OpenAIRE

    Carre, Emilie; Ogier, Michael; Boret, Henry; Montcriol, Ambroise; Bourdon, Lionel; Jean-Jacques, Risso

    2013-01-01

    Ischemia and metabolic crisis are frequent post-traumatic secondary brain insults that negatively influence outcome. Clinicians commonly mix up these two types of insults, mainly because high lactate/pyruvate ratio (LPR) is the common marker for both ischemia and metabolic crisis. However, LPR elevations during ischemia and metabolic crisis reflect two different energetic imbalances: ischemia (Type 1 LPR elevations with low oxygenation) is characterized by a drastic deprivation of energetic s...

  16. Heart Protection by Combination Therapy with Esmolol and Milrinone at Late-Ischemia and Early Reperfusion

    OpenAIRE

    Huang, Ming-He; Wu, Yewen; Nguyen, Vincent; Rastogi, Saurabh; McConnell, Bradley K.; Wijaya, Cori; Uretsky, Barry F.; Poh, Kian-Keong; Tan, Huay-Cheem; Fujise, Kenichi

    2011-01-01

    Introduction The present study determined whether late-ischemia/early reperfusion therapy with the β1-adrenergic receptor (AR) blocker esmolol and phosphodiesterase III inhibitor milrinone reduced left ventricular (LV) myocardial infarct size (IS). Methods and Results In an ischemia/reperfusion rat model (30-min ischemia/4-hr reperfusion), esmolol, milrinone or esmolol + milrinone were intravenous (IV) infused over 10 min (from the last 5min of ischemia to the first 5min of reperfusion). LV-I...

  17. Induction profile of MANF/ARMET by cerebral ischemia and its implication for neuron protection

    OpenAIRE

    Yu, Yong-Qiang; Liu, Lian-Cheng; Wang, Fa-Cai; Liang, Yan; Cha, Da-Qin; Zhang, Jing-Jing; Shen, Yu-Jun; Wang, Hai-Ping; Fang, Shengyun; Shen, Yu-Xian

    2009-01-01

    Cerebral ischemia-induced accumulation of unfolded proteins in vulnerable neurons triggers endoplasmic reticulum (ER) stress. Arginine-rich, mutated in early stage tumors (ARMET) is an ER stress-inducible protein and upregulated in the early stage of cerebral ischemia. The purposes of this study were to investigate the characteristics and implications of ARMET expression induced by focal cerebral ischemia. Focal cerebral ischemia in rats was induced by right middle cerebral artery occlusion w...

  18. Evaluation of myocardial ischemia by multiple detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Fabio Vieira, E-mail: rccury@me.com [Hospital do Coracao (HCor), Sao Paulo, SP (Brazil); Cury, Roberto Caldeira [Hospital Samaritano, Sao Paulo, SP (Brazil)

    2015-01-15

    For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemia and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study. (author)

  19. Characteristics and significance of ischemia detected by ambulatory electrocardiographic monitoring

    International Nuclear Information System (INIS)

    Nabel, E.G.; Rocco, M.B.; Selwyn, A.B.

    1987-01-01

    Ambulatory electrocardiographic (ECG) monitoring of ischemia in patients with coronary artery disease (CAD) provides a new technique for the assessment of ischemic activity and the evaluation of therapies outside of the hospital. Numerous studies have demonstrated that the majority of patients with CAD have episodes of symptomatic and asymptomatic ST segment depression during routine daily activities. Rubidium-82 positron-emission tomographic studies have provided evidence for decreased myocardial perfusion during these episodes of ST segment depression. The prognostic importance of asymptomatic ischemia has been shown in patients with unstable angina to be a marker for early unfavorable cardiac events. Preliminary results suggest a poorer outcome for those patients with chronic stable angina who show episodes of ischemia as well. Ambulatory monitoring studies suggest that total ischemic activity may be underestimated by conventional testing. Whether all ischemic activity detected by ambulatory monitoring requires treatment awaits further study. 69 references

  20. Myocardial perfusion imaging for detection of silent myocardial ischemia

    International Nuclear Information System (INIS)

    Beller, G.A.

    1988-01-01

    Despite the widespread use of the exercise stress test in diagnosing asymptomatic myocardial ischemia, exercise radionuclide imaging remains useful for detecting silent ischemia in numerous patient populations, including those who are totally asymptomatic, those who have chronic stable angina, those who have recovered from an episode of unstable angina or an uncomplicated myocardial infarction, and those who have undergone angioplasty or received thrombolytic therapy. Studies show that thallium scintigraphy is more sensitive than exercise electrocardiography in detecting ischemia, i.e., in part, because perfusion defects occur more frequently than ST depression and before angina in the ischemic cascade. Thallium-201 scintigraphy can be performed to differentiate a true- from a false-positive exercise electrocardiographic test in patients with exercise-induced ST depression and no angina. The development of technetium-labeled isonitriles may improve the accuracy of myocardial perfusion imaging. 11 references

  1. Effect of electroacupuncture on TRPM7 mRNA expression after cerebral ischemia/reperfusion in rats via TrkA pathway.

    Science.gov (United States)

    Zhao, Li; Shi, Jing; Sun, Ning; Tian, Shunlian; Meng, Xianfang; Liu, Xiaochun; Li, Lingli

    2005-01-01

    The effect of electroacupuncture (EA) on TRPM7 mRNA expression of focal cerebral ischemia in rats and further the role of EA in the relationship between TRPM7 and trkA pathway was investigated. Thirty SD rats were randomly divided into 5 groups : normal group, ischemia/reperfusion group, EA treated group (ischemic rats with EA treatment), TE infusion group (ischemic rats with EA treatment and TE buffer infusion), AS-ODN group (ischemic rats with EA treatment and antisense trkA oligonucleotide infusion). The stroke animal model was established by the modified method of middle cerebral artery occlusion. Antisense trkA oligonucleotide that blocked NGFs effects was injected into cerebroventricle before EA. The TRPM7 mRNA was detected by RT-PCR method. The results showed that there were low TRPM7 mRNA levels in cortex and hippocampus in normal group. Compared with normal group, TRPM7 mRNA expression was increased significantly in ischemia/reperfusion group (PPM7 mRNA was found in EA treated group in contrast to ischemia/reperfusion group (P<0.05). The expression of TRPM7 mRNA in AS-ODN group was remarkably increased compared with EA treated group and TE infusion group (P<0.05). The results indicated that TRPM7 channels in the ischemic cortex and hippocampus in rats might play a key role in ischemic brain injury. EA could reverse the overexpression of TRPM7 in cerebral ischemia/reperfusion rats. And the inhibitory effect of EA on TRPM7 channels might be through trkA pathway.

  2. Erythropoietin inhibits HIF-1α expression via upregulation of PHD-2 transcription and translation in an in-vitro model of hypoxia ischemia

    Science.gov (United States)

    Souvenir, Rhonda; Flores, Jerry J.; Ostrowski, Robert P.; Manaenko, Anatol; Duris, Kamil; Tang, Jiping

    2014-01-01

    Hypoxia inducible factor (HIF)-1α is the central transcriptional factor for the regulation of oxygen-associated genes in response to hypoxia. Erythropoietin (EPO), a hematopoietic growth factor, increases oxygen availability during hypoxia/ischemia and is associated with neuroprotection following hypoxia ischemia in laboratory models of stroke. However, EPO has failed to translate in a clinical setting. Thus it is critical to elucidate the key players in EPO-induced neuroprotection. Our preliminary studies have shown that EPO, as a downstream gene of hypoxia inducible factor (HIF), inhibits HIF-1α in a dose-dependent manner in an in-vitro model of hypoxia ischemia. This study is designed to elucidate the primary mediator of EPO-induced HIF-1α inhibition and subsequent cell survival/neuroprotection. Oxygen and glucose deprivation (OGD) of nerve growth factor (NGF) differentiated rat pheochromocytoma (PC-12) cells were used to model hypoxia ischemia in an in vitro environment. The profile of HIF-1α, HIF-2α and PHD-2 expression, HIF-1α and prolyl hydroxylase (PHD-2) mRNA levels, MMP-9 and cell death was evaluated in the presence and absence of either EPO or PHD-2 inhibitor during OGD. Our findings showed that EPO treatment resulted in an increase in PHD-2 transcription and translation, inhibition of HIF-1α expression, reactive oxygen species (ROS) formation and matrix metalloproteinase (MMP)-9 activity, resulting in increased cell survival after OGD. We also observed that EPO-induced cell survival/neuroprotection was reversed by siRNA silencing of PHD-2. This led to the conclusion that PHD-2 is a key mediator of EPO-induced HIF-1α inhibition and subsequent neuroprotection in an in vitro model of hypoxia ischemia. PMID:24323731

  3. Erythropoietin inhibits HIF-1α expression via upregulation of PHD-2 transcription and translation in an in vitro model of hypoxia-ischemia.

    Science.gov (United States)

    Souvenir, Rhonda; Flores, Jerry J; Ostrowski, Robert P; Manaenko, Anatol; Duris, Kamil; Tang, Jiping

    2014-02-01

    Hypoxia inducible factor (HIF)-1α is the central transcriptional factor for the regulation of oxygen-associated genes in response to hypoxia. Erythropoietin (EPO), a hematopoietic growth factor, increases oxygen availability during hypoxia/ischemia and is associated with neuroprotection following hypoxia-ischemia in laboratory models of stroke. However, EPO has failed to translate in a clinical setting. Thus, it is critical to elucidate the key players in EPO-induced neuroprotection. Our preliminary studies have shown that EPO, as a downstream gene of HIF, inhibits HIF-1α in a dose-dependent manner in an in vitro model of hypoxia-ischemia. This study is designed to elucidate the primary mediator of EPO-induced HIF-1α inhibition and subsequent cell survival/neuroprotection. Oxygen and glucose deprivation (OGD) of nerve growth factor-differentiated rat pheochromocytoma (PC-12) cells were used to model hypoxia-ischemia in an in vitro environment. The profile of HIF-1α, HIF-2α and prolyl hydroxylase domain 2 (PHD-2) expression; HIF-1α and prolyl hydroxylase (PHD-2) mRNA levels; matrix metalloproteinase (MMP)-9; and cell death was evaluated in the presence and absence of either EPO or PHD-2 inhibitor during OGD. Our findings showed that EPO treatment resulted in an increase in PHD-2 transcription and translation, inhibition of HIF-1α expression, reactive oxygen species formation, and MMP-9 activity, resulting in increased cell survival after OGD. We also observed that EPO-induced cell survival/neuroprotection was reversed by siRNA silencing of PHD-2. This led to the conclusion that PHD-2 is a key mediator of EPO-induced HIF-1α inhibition and subsequent neuroprotection in an in vitro model of hypoxia-ischemia.

  4. Economic impact of reversion

    International Nuclear Information System (INIS)

    2005-01-01

    Estimations of the Norwegian hydropower production and various reversion models' market value have been made. The value of the Norwegian hydropower production until 01.01.2007 is estimated to about Nok 289 billion after taxes, or about 2,42 Nok/kWh medium production, given an expected future electricity price of around 0,25 Nok/kWh and a discount rate at 6,5 percent in nominal terms after taxes. The estimate is slightly above the level of prices for Norwegian hydropower plants in the last 8-10 years. The value of reversion in private plants which today have a limited licence time is estimated to Nok 5,5 billion. The value of reversion in public-owned Norwegian hydropower plants are about Nok 21 billion with a 60 year licence period from 01.01.2007, and about 12 billion for 75 years (ml)

  5. The Neuroprotective Effect of Kefir on Spinal Cord Ischemia/Reperfusion Injury in Rats

    Science.gov (United States)

    Akman, Tarik; Yener, Ali Umit; Sehitoglu, Muserref Hilal; Yuksel, Yasemin; Cosar, Murat

    2015-01-01

    Objective The main causes of spinal cord ischemia are a variety of vascular pathologies causing acute arterial occlusions. We investigated neuroprotective effects of kefir on spinal cord ischemia injury in rats. Methods Rats were divided into three groups : 1) sham operated control rats; 2) spinal cord ischemia group fed on a standard diet without kefir pretreatment; and 3) spinal cord ischemia group fed on a standard diet plus kefir. Spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. The spinal cord was removed after the procedure. The biochemical and histopathological changes were observed within the samples. Functional assessment was performed for neurological deficit scores. Results The kefir group was compared with the ischemia group, a significant decrease in malondialdehyde levels was observed (pkefir group were significantly higher than ischemia group (pkefir group is compared with ischemia group, there was a significant decrease in numbers of dead and degenerated neurons (pkefir group compared with ischemia group (pkefir group were significantly higher than ischemia group at 24 h (pkefir pretreatment in spinal cord ischemia/reperfusion reduced oxidative stress and neuronal degeneration as a neuroprotective agent. Ultrastructural studies are required in order for kefir to be developed as a promising therapeutic agent to be utilized for human spinal cord ischemia in the future. PMID:26113960

  6. EFFICACY OF METOPROLOL AND DILTIAZEM IN TREATING SILENT-MYOCARDIAL-ISCHEMIA

    NARCIS (Netherlands)

    PORTEGIES, MCM; SIJBRING, P; GOBEL, JAM; VIERSMA, JW; LIE, KI

    1994-01-01

    Recent studies strongly support the prognostic importance of transient silent ischemia. Because patients with silent ischemia are at higher risk of a cardiac event, they are likely to benefit not only from control of symptoms, but also from treatment directed at prevention of ischemia. The efficacy

  7. Exercise preconditioning exhibits neuroprotective effects on hippocampal CA1 neuronal damage after cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Nabi Shamsaei; Mehdi Khaksari; Sohaila Erfani; Hamid Rajabi; Nahid Aboutaleb

    2015-01-01

    Recent evidence has suggested the neuroprotective effects of physical exercise on cerebral isch-emic injury. However, the role of physical exercise in cerebral ischemia-induced hippocampal damage remains controversial. The aim of the present study was to evaluate the effects of pre-ischemia treadmill training on hippocampal CA1 neuronal damage after cerebral ischemia. Male adult rats were randomly divided into control, ischemia and exercise + ischemia groups. In the exercise + ischemia group, rats were subjected to running on a treadmill in a designated time schedule (5 days per week for 4 weeks). Then rats underwent cerebral ischemia induction th rough occlusion of common carotids followed by reperfusion. At 4 days after cerebral ischemia, rat learning and memory abilities were evaluated using passive avoidance memory test and rat hippocampal neuronal damage was detected using Nissl and TUNEL staining. Pre-ischemic ex-ercise signiifcantly reduced the number of TUNEL-positive cells and necrotic cell death in the hippocampal CA1 region as compared to the ischemia group. Moreover, pre-ischemic exercise significantly prevented ischemia-induced memory dysfunction. Pre-ischemic exercise mighct prevent memory deficits after cerebral ischemia through rescuing hippocampal CA1 neurons from ischemia-induced degeneration.

  8. The Neuroprotective Effect of Kefir on Spinal Cord Ischemia/Reperfusion Injury in Rats.

    Science.gov (United States)

    Guven, Mustafa; Akman, Tarik; Yener, Ali Umit; Sehitoglu, Muserref Hilal; Yuksel, Yasemin; Cosar, Murat

    2015-05-01

    The main causes of spinal cord ischemia are a variety of vascular pathologies causing acute arterial occlusions. We investigated neuroprotective effects of kefir on spinal cord ischemia injury in rats. Rats were divided into three groups : 1) sham operated control rats; 2) spinal cord ischemia group fed on a standard diet without kefir pretreatment; and 3) spinal cord ischemia group fed on a standard diet plus kefir. Spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. The spinal cord was removed after the procedure. The biochemical and histopathological changes were observed within the samples. Functional assessment was performed for neurological deficit scores. The kefir group was compared with the ischemia group, a significant decrease in malondialdehyde levels was observed (pkefir group were significantly higher than ischemia group (pkefir group is compared with ischemia group, there was a significant decrease in numbers of dead and degenerated neurons (pkefir group compared with ischemia group (pkefir group were significantly higher than ischemia group at 24 h (pkefir pretreatment in spinal cord ischemia/reperfusion reduced oxidative stress and neuronal degeneration as a neuroprotective agent. Ultrastructural studies are required in order for kefir to be developed as a promising therapeutic agent to be utilized for human spinal cord ischemia in the future.

  9. Treatment of critical lower limb ischemia using a hybrid technique

    Directory of Open Access Journals (Sweden)

    Ricardo Wagner da Costa Moreira

    2014-09-01

    Full Text Available Critical ischemia of a lower limb is a condition that threatens its viability and must be treated promptly to avoid major amputation. Revascularization is the most effective treatment method and is performed using surgical or endovascular techniques. For patients with thoracoabdominal aortic aneurysms, combining these two approaches into a "hybrid technique" makes it possible to treat patients who could not be adequately treated by either technique in isolation. We report on a case of lower limb critical ischemia treated using a combination of surgery and endovascular techniques, in an application of the hybrid technique in a different arterial bed.

  10. Reversible deep disposal

    International Nuclear Information System (INIS)

    2009-10-01

    This presentation, given by the national agency of radioactive waste management (ANDRA) at the meeting of October 8, 2009 of the high committee for the nuclear safety transparency and information (HCTISN), describes the concept of deep reversible disposal for high level/long living radioactive wastes, as considered by the ANDRA in the framework of the program law of June 28, 2006 about the sustainable management of radioactive materials and wastes. The document presents the social and political reasons of reversibility, the technical means considered (containers, disposal cavities, monitoring system, test facilities and industrial prototypes), the decisional process (progressive development and blocked off of the facility, public information and debate). (J.S.)

  11. Neuroprotective effect of TAT-14-3-3ε fusion protein against cerebral ischemia/reperfusion injury in rats.

    Directory of Open Access Journals (Sweden)

    Yuanjun Zhu

    Full Text Available Stroke is the major cause of death and disability worldwide, and the thrombolytic therapy currently available was unsatisfactory. 14-3-3ε is a well characterized member of 14-3-3 family, and has been reported to protect neurons against apoptosis in cerebral ischemia. However, it cannot transverse blood brain barrier (BBB due to its large size. A protein transduction domain (PTD of HIV TAT protein, is capable of delivering a large variety of proteins into the brain. In this study, we generated a fusion protein TAT-14-3-3ε, and evaluated its potential neuroprotective effect in rat focal ischemia/reperfusion (I/R model. Western blot analysis validated the efficient transduction of TAT-14-3-3ε fusion protein into brain via a route of intravenous injection. TAT-14-3-3ε pre-treatment 2 h before ischemia significantly reduced cerebral infarction volume and improved neurologic score, while post-treatment 2 h after ischemia was less effective. Importantly, pre- or post-ischemic treatment with TAT-14-3-3ε significantly increased the number of surviving neurons as determined by Nissl staining, and attenuated I/R-induced neuronal apoptosis as showed by the decrease in apoptotic cell numbers and the inhibition of caspase-3 activity. Moreover, the introduction of 14-3-3ε into brain by TAT-mediated delivering reduced the formation of autophagosome, attenuated LC3B-II upregulation and reversed p62 downregulation induced by ischemic injury. Such inhibition of autophagy was reversed by treatment with an autophagy inducer rapamycin (RAP, which also attenuated the neuroprotective effect of TAT-14-3-3ε. Conversely, autophagy inhibitor 3-methyladenine (3-MA inhibited I/R-induced the increase in autophagic activity, and attenuated I/R-induced brain infarct. These results suggest that TAT-14-3-3ε can be efficiently transduced into brain and exert significantly protective effect against brain ischemic injury through inhibiting neuronal apoptosis and autophagic

  12. Thermosensory reversal effect quantified

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kappers, A.M.L.

    2008-01-01

    At room temperature, some materials feel colder than others due to differences in thermal conductivity, heat capacity and geometry. When the ambient temperature is well above skin temperature, the roles of 'cold' and 'warm' materials are reversed. In this paper, this effect is quantified by

  13. Thermosensory reversal effect quantified

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kappers, A.M.L.

    2008-01-01

    At room temperature, some materials feel colder than others due to differences in thermal conductivity, heat capacity and geometry. When the ambient temperature is well above skin temperature, the roles of ‘cold’ and ‘warm’ materials are reversed. In this paper, this effect is quantified by

  14. Time reversal communication system

    Science.gov (United States)

    Candy, James V.; Meyer, Alan W.

    2008-12-02

    A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

  15. Engineering Encounters: Reverse Engineering

    Science.gov (United States)

    McGowan, Veronica Cassone; Ventura, Marcia; Bell, Philip

    2017-01-01

    This column presents ideas and techniques to enhance your science teaching. This month's issue shares information on how students' everyday experiences can support science learning through engineering design. In this article, the authors outline a reverse-engineering model of instruction and describe one example of how it looked in our fifth-grade…

  16. Sex Reversal in Birds.

    Science.gov (United States)

    Major, Andrew T; Smith, Craig A

    2016-01-01

    Sexual differentiation in birds is controlled genetically as in mammals, although the sex chromosomes are different. Males have a ZZ sex chromosome constitution, while females are ZW. Gene(s) on the sex chromosomes must initiate gonadal sex differentiation during embryonic life, inducing paired testes in ZZ individuals and unilateral ovaries in ZW individuals. The traditional view of avian sexual differentiation aligns with that expounded for other vertebrates; upon sexual differentiation, the gonads secrete sex steroid hormones that masculinise or feminise the rest of the body. However, recent studies on naturally occurring or experimentally induced avian sex reversal suggest a significant role for direct genetic factors, in addition to sex hormones, in regulating sexual differentiation of the soma in birds. This review will provide an overview of sex determination in birds and both naturally and experimentally induced sex reversal, with emphasis on the key role of oestrogen. We then consider how recent studies on sex reversal and gynandromorphic birds (half male:half female) are shaping our understanding of sexual differentiation in avians and in vertebrates more broadly. Current evidence shows that sexual differentiation in birds is a mix of direct genetic and hormonal mechanisms. Perturbation of either of these components may lead to sex reversal. © 2016 S. Karger AG, Basel.

  17. Elastomers with Reversible Nanoporosity

    DEFF Research Database (Denmark)

    Szewczykowski, Piotr Przemyslaw; Andersen, K.; Schulte, Lars

    2009-01-01

    nanostructure and displays liquid-filled cavities. Upon several cycles of swelling and drying the cavities open and close in a reversible fashion. When exposed to a nonsolvent, the material remains collapsed. This discriminating behavior of liquid-material interaction holds potential for the use...

  18. Gene expression related to oxidative stress in the heart of mice after intestinal ischemia

    International Nuclear Information System (INIS)

    Somaio Neto, Frederico; Ikejiri, Adauto Tsutomu; Bertoletto, Paulo Roberto; Chaves, José Carlos Bertoletto; Teruya, Roberto; Fagundes, Djalma José; Taha, Murched Omar

    2014-01-01

    Intestinal ischemia-reperfusion is a frequent clinical event associated to injury in distant organs, especially the heart. To investigate the gene expression of oxidative stress and antioxidant defense in the heart of inbred mice subjected to intestinal ischemia and reperfusion (IR). Twelve mice (C57BL / 6) were assigned to: IR Group (GIR) with 60 minutes of superior mesenteric artery occlusion followed by 60 minutes of reperfusion; Control Group (CG) which underwent anesthesia and laparotomy without IR procedure and was observed for 120 minutes. Intestine and heart samples were processed using the RT-qPCR / Reverse transcriptase-quantitative Polymerase Chain Reaction method for the gene expression of 84 genes related to oxidative stress and oxidative defense (Student's 't' test, p < 0.05). The intestinal tissue (GIR) was noted to have an up-regulation of 65 genes (74.71%) in comparison to normal tissue (CG), and 37 genes (44.04%) were hyper-expressed (greater than three times the threshold allowed by the algorithm). Regarding the remote effects of intestinal I/R in cardiac tissue an up-regulation of 28 genes (33.33%) was seen, but only eight genes (9.52%) were hyper-expressed three times above threshold. Four (7.14%) of these eight genes were expressed in both intestinal and cardiac tissues. Cardiomyocytes with smaller and pyknotic nuclei, rich in heterochromatin with rare nucleoli, indicating cardiac distress, were observed in the GIR. Intestinal I/R caused a statistically significant over expression of 8 genes associated with oxidative stress in remote myocardial tissue

  19. Silent myocardial ischemia in patients with symptomatic intracranial atherosclerosis: associated factors.

    Science.gov (United States)

    Arenillas, Juan F; Candell-Riera, Jaume; Romero-Farina, Guillermo; Molina, Carlos A; Chacón, Pilar; Aguadé-Bruix, Santiago; Montaner, Joan; de León, Gustavo; Castell-Conesa, Joan; Alvarez-Sabín, José

    2005-06-01

    Optimization of coronary risk evaluation in stroke patients has been encouraged. The relationship between symptomatic intracranial atherosclerosis and occult coronary artery disease (CAD) has not been evaluated sufficiently. We aimed to investigate the prevalence of silent myocardial ischemia in patients with symptomatic intracranial atherosclerosis and to identify factors associated with its presence. From 186 first-ever transient ischemic attack or ischemic stroke patients with intracranial stenoses, 65 fulfilled selection criteria, including angiographic confirmation of a symptomatic atherosclerotic stenosis and absence of known CAD. All patients underwent a maximal-stress myocardial perfusion single-photon emission computed tomography (SPECT). Lipoprotein(a) [Lp(a)], C-reactive protein, and homocysteine (Hcy) levels were determined before SPECT. Stress-rest SPECT detected reversible myocardial perfusion defects in 34 (52%) patients. Vascular risk factors associated with a pathologic SPECT were hypercholesterolemia (P=0.045), presence of >2 risk factors (P=0.004) and high Lp(a) (P=0.023) and Hcy levels (P=0.018). Ninety percent of patients with high Lp(a) and Hcy levels had a positive SPECT. Existence of a stenosed intracranial internal carotid artery (ICA; odds ratio [OR], 7.22, 2.07 to 25.23; P=0.002) and location of the symptomatic stenosis in vertebrobasilar arteries (OR, 4.89, 1.19 to 20.12; P=0.027) were independently associated with silent myocardial ischemia after adjustment by age, sex, and risk factors. More than 50% of the patients with symptomatic intracranial atherosclerosis and not overt CAD show myocardial perfusion defects on stress-rest SPECT. Stenosed intracranial ICA, symptomatic vertebrobasilar stenosis and presence of high Lp(a) and Hcy levels may characterize the patients at a higher risk for occult CAD.

  20. Electroacupuncture-Induced Neuroprotection against Cerebral Ischemia in Rats: Role of the Dopamine D2 Receptor

    Directory of Open Access Journals (Sweden)

    Ming-Shu Xu

    2013-01-01

    Full Text Available Background. Cerebral ischemia is known to produce brain damage and related behavioural deficits, including memory deficits and motor disorders. Evidence shows that EA significantly promotes recovery of neurological function and thus improves quality of life. Objective. Evidence exists for the involvement of catecholamines in human neuroplasticity. A better understanding of dopaminergic (DAergic modulation in this process will be important. Methods. A total of 72 adult male Sprague-Dawley (SD rats were divided into 6 groups: normal, model, EA, spiperone group, EA + spiperone group, and pergolide. The middle cerebral artery occlusion (MCAO model was used in all 6 groups except the normal group. A behavioural assessment was conducted at 1, 3, 5, and 7 days after MCAO. The percent of brain infarct area was also determined 7 days after MCAO. Tyrosine hydroxylase (TH and growth-associated protein 43 (GAP-43 fluorescence double labeling was performed in the striatum. Results. In this study, we found that EA at Fengchi (GB20 acupoints resulted in marked improvements based on a behavioural assessment. Both TTC staining and GAP-43 immunofluorescence labeling results showed that EA treatment reduced ischemia injury and promoted neuroplasticity compared with the model group. The D2R-selective agonist, pergolide, showed similar results, but these results were reversed by the D2R-selective antagonist, spiperone. We also found that there were more colocalization and expression of GAP-43 and TH in the EA and pergolide groups than those in the other groups. Conclusion. These results suggest that the neuroplasticity induced by EA was mediated by D2 autoreceptors in DAergic neurons.

  1. Improving reconstituted HDL composition for efficient post-ischemic reduction of ischemia reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Marie-Claude Brulhart-Meynet

    Full Text Available New evidence shows that high density lipoproteins (HDL have protective effects beyond their role in reverse cholesterol transport. Reconstituted HDL (rHDL offer an attractive means of clinically exploiting these novel effects including cardioprotection against ischemia reperfusion injury (IRI. However, basic rHDL composition is limited to apolipoprotein AI (apoAI and phospholipids; addition of bioactive compound may enhance its beneficial effects.The aim of this study was to investigate the role of rHDL in post-ischemic model, and to analyze the potential impact of sphingosine-1-phosphate (S1P in rHDL formulations.The impact of HDL on IRI was investigated using complementary in vivo, ex vivo and in vitro IRI models. Acute post-ischemic treatment with native HDL significantly reduced infarct size and cell death in the ex vivo, isolated heart (Langendorff model and the in vivo model (-48%, p<0.01. Treatment with rHDL of basic formulation (apoAI + phospholipids had a non-significant impact on cell death in vitro and on the infarct size ex vivo and in vivo. In contrast, rHDL containing S1P had a highly significant, protective influence ex vivo, and in vivo (-50%, p<0.01. This impact was comparable with the effects observed with native HDL. Pro-survival signaling proteins, Akt, STAT3 and ERK1/2 were similarly activated by HDL and rHDL containing S1P both in vitro (isolated cardiomyocytes and in vivo.HDL afford protection against IRI in a clinically relevant model (post-ischemia. rHDL is significantly protective if supplemented with S1P. The protective impact of HDL appears to target directly the cardiomyocyte.

  2. Gene expression related to oxidative stress in the heart of mice after intestinal ischemia

    Science.gov (United States)

    Somaio Neto, Frederico; Ikejiri, Adauto Tsutomu; Bertoletto, Paulo Roberto; Chaves, José Carlos Bertoletto; Teruya, Roberto; Fagundes, Djalma José; Taha, Murched Omar

    2014-01-01

    Background Intestinal ischemia-reperfusion is a frequent clinical event associated to injury in distant organs, especially the heart. Objective To investigate the gene expression of oxidative stress and antioxidant defense in the heart of inbred mice subjected to intestinal ischemia and reperfusion (IR). Methods Twelve mice (C57BL / 6) were assigned to: IR Group (GIR) with 60 minutes of superior mesenteric artery occlusion followed by 60 minutes of reperfusion; Control Group (CG) which underwent anesthesia and laparotomy without IR procedure and was observed for 120 minutes. Intestine and heart samples were processed using the RT-qPCR / Reverse transcriptase-quantitative Polymerase Chain Reaction method for the gene expression of 84 genes related to oxidative stress and oxidative defense (Student's "t" test, p < 0.05). Results The intestinal tissue (GIR) was noted to have an up-regulation of 65 genes (74.71%) in comparison to normal tissue (CG), and 37 genes (44.04%) were hyper-expressed (greater than three times the threshold allowed by the algorithm). Regarding the remote effects of intestinal I/R in cardiac tissue an up-regulation of 28 genes (33.33%) was seen, but only eight genes (9.52%) were hyper-expressed three times above threshold. Four (7.14%) of these eight genes were expressed in both intestinal and cardiac tissues. Cardiomyocytes with smaller and pyknotic nuclei, rich in heterochromatin with rare nucleoli, indicating cardiac distress, were observed in the GIR. Conclusion Intestinal I/R caused a statistically significant over expression of 8 genes associated with oxidative stress in remote myocardial tissue. PMID:24346830

  3. Gene expression related to oxidative stress in the heart of mice after intestinal ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Somaio Neto, Frederico; Ikejiri, Adauto Tsutomu; Bertoletto, Paulo Roberto; Chaves, José Carlos Bertoletto [Universidade Federal da Grande Dourados - UFGD, Dourados, MS (Brazil); Teruya, Roberto [Universidade Federal do Mato Grosso do Sul - UFMS, Campo Grande, MS (Brazil); Fagundes, Djalma José, E-mail: fsomaio@cardiol.br; Taha, Murched Omar [Universidade Federal de São Paulo - UNIFESP, São Paulo, SP (Brazil)

    2014-02-15

    Intestinal ischemia-reperfusion is a frequent clinical event associated to injury in distant organs, especially the heart. To investigate the gene expression of oxidative stress and antioxidant defense in the heart of inbred mice subjected to intestinal ischemia and reperfusion (IR). Twelve mice (C57BL / 6) were assigned to: IR Group (GIR) with 60 minutes of superior mesenteric artery occlusion followed by 60 minutes of reperfusion; Control Group (CG) which underwent anesthesia and laparotomy without IR procedure and was observed for 120 minutes. Intestine and heart samples were processed using the RT-qPCR / Reverse transcriptase-quantitative Polymerase Chain Reaction method for the gene expression of 84 genes related to oxidative stress and oxidative defense (Student's 't' test, p < 0.05). The intestinal tissue (GIR) was noted to have an up-regulation of 65 genes (74.71%) in comparison to normal tissue (CG), and 37 genes (44.04%) were hyper-expressed (greater than three times the threshold allowed by the algorithm). Regarding the remote effects of intestinal I/R in cardiac tissue an up-regulation of 28 genes (33.33%) was seen, but only eight genes (9.52%) were hyper-expressed three times above threshold. Four (7.14%) of these eight genes were expressed in both intestinal and cardiac tissues. Cardiomyocytes with smaller and pyknotic nuclei, rich in heterochromatin with rare nucleoli, indicating cardiac distress, were observed in the GIR. Intestinal I/R caused a statistically significant over expression of 8 genes associated with oxidative stress in remote myocardial tissue.

  4. Does the intrathecal propofol have a neuroprotective effect on spinal cord ischemia?

    Science.gov (United States)

    Sahin, Murat; Gullu, Huriye; Peker, Kemal; Sayar, Ilyas; Binici, Orhan; Yildiz, Huseyin

    2015-11-01

    The neuroprotective effects of propofol have been confirmed. However, it remains unclear whether intrathecal administration of propofol exhibits neuroprotective effects on spinal cord ischemia. At 1 hour prior to spinal cord ischemia, propofol (100 and 300 µg) was intrathecally administered in rats with spinal cord ischemia. Propofol pre-treatment greatly improved rat pathological changes and neurological function deficits at 24 hours after spinal cord ischemia. These results suggest that intrathecal administration of propofol exhibits neuroprotective effects on spinal cord structural and functional damage caused by ischemia.

  5. Does the intrathecal propofol have a neuroprotective effect on spinal cord ischemia?

    Directory of Open Access Journals (Sweden)

    Murat Sahin

    2015-01-01

    Full Text Available The neuroprotective effects of propofol have been confirmed. However, it remains unclear whether intrathecal administration of propofol exhibits neuroprotective effects on spinal cord ischemia. At 1 hour prior to spinal cord ischemia, propofol (100 and 300 µg was intrathecally administered in rats with spinal cord ischemia. Propofol pre-treatment greatly improved rat pathological changes and neurological function deficits at 24 hours after spinal cord ischemia. These results suggest that intrathecal administration of propofol exhibits neuroprotective effects on spinal cord structural and functional damage caused by ischemia.

  6. [The relationship between ischemic preconditioning-induced infarction size limitation and duration of test myocardial ischemia].

    Science.gov (United States)

    Blokhin, I O; Galagudza, M M; Vlasov, T D; Nifontov, E M; Petrishchev, N N

    2008-07-01

    Traditionally infarction size reduction by ischemic preconditioning is estimated in duration of test ischemia. This approach limits the understanding of real antiischemic efficacy of ischemic preconditioning. Present study was performed in the in vivo rat model of regional myocardial ischemia-reperfusion and showed that protective effect afforded by ischemic preconditioning progressively decreased with prolongation of test ischemia. There were no statistically significant differences in infarction size between control and preconditioned animals when the duration of test ischemia was increased up to 1 hour. Preconditioning ensured maximal infarction-limiting effect in duration of test ischemia varying from 20 to 40 minutes.

  7. Ligustrazine monomer against cerebral ischemia-reperfusion injury

    Directory of Open Access Journals (Sweden)

    Hai-jun Gao

    2015-01-01

    Full Text Available Ligustrazine (2,3,5,6-tetramethylpyrazine is a major active ingredient of the Szechwan lovage rhizome and is extensively used in treatment of ischemic cerebrovascular disease. The mechanism of action of ligustrazine use against ischemic cerebrovascular diseases remains unclear at present. This study summarizes its protective effect, the optimum time window of administration, and the most effective mode of administration for clinical treatment of cerebral ischemia/reperfusion injury. We examine the effects of ligustrazine on suppressing excitatory amino acid release, promoting migration, differentiation and proliferation of endogenous neural stem cells. We also looked at its effects on angiogenesis and how it inhibits thrombosis, the inflammatory response, and apoptosis after cerebral ischemia. We consider that ligustrazine gives noticeable protection from cerebral ischemia/reperfusion injury. The time window of ligustrazine administration is limited. The protective effect and time window of a series of derivative monomers of ligustrazine such as 2-[(1,1-dimethylethyloxidoimino]methyl]-3,5,6-trimethylpyrazine, CXC137 and CXC195 after cerebral ischemia were better than ligustrazine.

  8. Myocardial Ischemia Screening in Middle-Aged and Elderly Men

    Czech Academy of Sciences Publication Activity Database

    Boudík, F.; Reissigová, Jindra; Tomečková, Marie; Anger, Z.; Bultas, J.; Šimek, S.

    2010-01-01

    Roč. 17, č. 5 (2010), s. 2-7 ISSN 1667-9059 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : body surface mapping * stress ECG test * myocardial ischemia * risk factors Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  9. Delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: clinicoanatomic correlations

    NARCIS (Netherlands)

    Hijdra, A.; van Gijn, J.; Stefanko, S.; van Dongen, K. J.; Vermeulen, M.; van Crevel, H.

    1986-01-01

    Fifty-seven of 176 prospectively studied patients with aneurysmal subarachnoid hemorrhage (SAH) developed delayed cerebral ischemia. Clinical features included hemispheric focal signs (13), decrease in level of consciousness (14), or both (30), and mutism (15). Forty-seven patients showed hypodense

  10. Effect Of Ischemia-Reperfusion On Healing In Intestinal Anastomosis ...

    African Journals Online (AJOL)

    The effect of reperfusion injury on the healing of intestinal anastomotic wound directly subjected to ischemia-reperfusion stress was investigated in dogs. Three groups of dogs were utilized for the study. In group A (Control) cranial mesenteric artery and collateral blood supply were isolated but not occluded. In groups B and ...

  11. Energy Drinks and Myocardial Ischemia: A Review of Case Reports.

    Science.gov (United States)

    Lippi, Giuseppe; Cervellin, Gianfranco; Sanchis-Gomar, Fabian

    2016-07-01

    The use and abuse of energy drinks (EDs) is constantly increasing worldwide. We performed a systematic search in Medline, Scopus and Web of Science to identify evidence about the potential link between these beverages and myocardial ischemia. Overall, 8 case reports could be detected, all of which described a realistic association between large intake of EDs and episodes of myocardial ischemia. Interestingly, no additional triggers of myocardial ischemia other than energy drinks could be identified in the vast majority of cases. Some plausible explanations can be brought in support of this association. Most of the biological effects of EDs are seemingly mediated by a positive inotropic effect on cardiac function, which entails increase in heart rate, cardiac output and contractility, stroke volume and arterial blood pressure. Additional biological abnormalities reported after EDs intake include increased platelet aggregation, endothelial dysfunction, hyperglycemia as well as an increase in total cholesterol, triglycerides and low-density lipoprotein cholesterol. Although a causal relationship between large consumption of EDs and myocardial ischemia cannot be definitely established so far, concerns about the cardiovascular risk of excessive consumption of these beverages are seemingly justified.

  12. Nootropics in a Complex Therapy of Chronic Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Chekman, I.S.

    2014-07-01

    Full Text Available Clinical and pharmacological characteristics of nootropics — one of the most productive groups of neuropsychotropic drugs, are considered. Classification of nootropics based on the main mechanism of action is constructed. The examples of clinical use of drugs in patients with chronic cerebral ischemia are presented.

  13. Nootropics in a Complex Therapy of Chronic Cerebral Ischemia

    OpenAIRE

    Chekman, I.S.; Belenichev, I.F.; Demchenko, A.V.; Bobrova, V.I.; Kucherenko, L.I.; Gorchakova, N.A.; Bukhtiyarova, N.V.

    2014-01-01

    Clinical and pharmacological characteristics of nootropics — one of the most productive groups of neuropsychotropic drugs, are considered. Classification of nootropics based on the main mechanism of action is constructed. The examples of clinical use of drugs in patients with chronic cerebral ischemia are presented.

  14. Nitrite enhances liver graft protection against cold ischemia ...

    African Journals Online (AJOL)

    Amani Cherif-Sayadi

    2017-03-30

    Mar 30, 2017 ... cold ischemia reperfusion injury through a NOS ... oxidation and lipid peroxidation remained at low levels in both nitrite-treated groups when ... liver graft preservation [15]. ... nitrite activity is dependent on NO production but .... LiversT rat (n = 6) were flushed and preserved in IGL-1 solution ..... The nitrate-.

  15. The need to reduce cold ischemia time in kidney transplantation

    NARCIS (Netherlands)

    Vliet, J.A. van der; Warle, M.C.

    2013-01-01

    PURPOSE OF REVIEW: Hypothermic preservation is a prerequisite for kidney exchange in transplantation. The severity of tissue damage caused by hypothermic preservation influences the level of ischemia/reperfusion injury and subsequent graft function. With the purpose of reviewing the implications of

  16. Protective effect of salvianolic acid B against intestinal ischemia ...

    African Journals Online (AJOL)

    Conclusion: The results of this study demonstrate that SAB may protect the intestine by attenuating oxidative stress and inflammatory response and hence, may be potentially for treating IIRI. Keywords: Salvianolic acid B, Intestinal Ischemia-reperfusion, Antioxidants, Inflammation, Intestinal permeability ...

  17. Neonatal cardiac mitochondria and ischemia/reperfusion injury

    Czech Academy of Sciences Publication Activity Database

    Milerová, Marie; Charvátová, Zuzana; Škárka, Libor; Ošťádalová, Ivana; Drahota, Zdeněk; Fialová, Martina; Ošťádal, Bohuslav

    2010-01-01

    Roč. 335, 1-2 (2010), s. 147-153 ISSN 0300-8177 R&D Projects: GA MŠk(CZ) 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : neonatal rat heart * tolerance to ischemia * mitochondrial permeability transition pore Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 2.168, year: 2010

  18. Neuroprotective effects of female sex steroids in cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Drača Sanja

    2013-03-01

    Full Text Available The central and peripheral nervous system are important targets of sex steroids. Sex steroids affect the brain development and differentiation, and influence neuronal functions. Recent evidence emphasizes a striking sex-linked difference in brain damage after experimental stroke, as well as the efficacy of hormones in treating cerebral stroke injury. Several different models of cerebral ischemia have been utilized for hormone neuroprotection studies, including transient or permanent middle cerebral artery occlusion, transient global ischemia, and transient forebrain ischemia. Extensive experimental studies have shown that female sex steroids such as progesterone and 176-estradiol exert neuroprotective effects in the experimental models of stroke, although deleterious effects have also been reported. Also, a significance of numerous factors, including gender and age of experimental animals, localization of brain lesion, duration of ischemia and precise dose of steroids has been pointed out. There are multiple potential mechanisms that might be invoked to explain the beneficial effects of female sex steroids in brain injury, involving neuroprotection, anti-inflammatory properties, effects on vasculature and altered transcriptional regulation. A several clinical trials on the effects of sex hormones to traumatic brain injury have been performed, suggesting that hormone therapy may represent a new therapeutic tool to combat certain diseases, such as traumatic brain injury. Further basic science studies and randomized clinical trials are necessary to reveal a potential application of these molecules as a new therapeutic strategy.

  19. Changes in functional status after treatment of critical limb ischemia

    NARCIS (Netherlands)

    Frans, Franceline Alkine; Met, Rosemarie; Koelemay, Mark J. W.; Bipat, Shandra; Dijkgraaf, Marcel G. W.; Legemate, Dink A.; Reekers, Jim A.

    2013-01-01

    This study evaluated changes in functional status with the Academic Medical Center Linear Disability Score (ALDS) and in quality of life with the Vascular Quality of Life Questionnaire (VascuQol) in patients treated for critical limb ischemia (CLI). We conducted a prospective observational cohort

  20. Myocardial Ischemia Screening in Middle-Aged and Elderly Men

    Czech Academy of Sciences Publication Activity Database

    Boudík, F.; Reissigová, Jindra; Tomečková, Marie; Anger, Z.; Bultas, J.; Šimek, S.

    2010-01-01

    Roč. 17, č. 4 (2010), s. 352-356 ISSN 1667-8982 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : body surface mapping * stress ECG test * myocardial ischemia * risk factors Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.028, year: 2010

  1. The sterile immune response during hepatic ischemia/reperfusion

    NARCIS (Netherlands)

    van Golen, Rowan F.; van Gulik, Thomas M.; Heger, Michal

    2012-01-01

    Hepatic ischemia and reperfusion elicits an immune response that lacks a microbial constituent yet poses a potentially lethal threat to the host. In this sterile setting, the immune system is alarmed by endogenous danger signals that are release by stressed and dying liver cells. The detection of

  2. Clinical effectiveness of percutaneous angioplasty for acute and chronic mesenteric ischemia: a six case series.

    Science.gov (United States)

    Jung, Yu Min; Jo, Yun Ju; Ahn, Sang Bong; Son, Byoung Kwan; Kim, Seong Hwan; Park, Young Sook; Bae, June Ho; Cho, Young Kwon

    2011-04-01

    Intestinal ischemia is divided into three categories, namely, acute mesenteric ischemia (AMI), chronic mesenteric ischemia (CMI), and colonic ischemia. AMI can result from arterial or venous thrombi, emboli, and vasoconstriction secondary to low-flow states. It is an urgent condition which can result in high mortality rate. The predominant causative factor of CMI is stenosis or occlusion of the mesenteric arterial circulation, and it is characterized by postprandial abdominal pain and weight loss. Surgery is the treatment of choice for intestinal ischemia. However, it has been recently reported that percutaneous transluminal angioplasty with stent placement and/or thrombolysis is an effective therapy in various types of mesenteric ischemia. We report six cases of mesenteric ischemia which were successfully treated by percutaneous angioplasty, and review the literature from South Korea.

  3. Angina and exertional myocardial ischemia in diabetic and nondiabetic patients: assessment by exercise thallium scintigraphy

    International Nuclear Information System (INIS)

    Nesto, R.W.; Phillips, R.T.; Kett, K.G.; Hill, T.; Perper, E.; Young, E.; Leland, O.S. Jr.

    1988-01-01

    Patients with diabetes mellitus and coronary artery disease are thought to have painless myocardial ischemia more often than patients without diabetes. We studied 50 consecutive patients with diabetes and 50 consecutive patients without diabetes, all with ischemia, on exercise thallium scintigraphy to show the reliability of angina as a marker for exertional ischemia. The two groups had similar clinical characteristics, treadmill test results, and extent of infarction and ischemia, but only 7 patients with diabetes compared with 17 patients without diabetes had angina during exertional ischemia. In diabetic patients the extent of retinopathy, nephropathy, or peripheral neuropathy was similar in patients with and without angina. Angina is an unreliable index of myocardial ischemia in diabetic patients with coronary artery disease. Given the increased cardiac morbidity and mortality in such patients, periodic objective assessments of the extent of ischemia are warranted

  4. Intracellular postsynaptic cannabinoid receptors link thyrotropin-releasing hormone receptors to TRPC-like channels in thalamic paraventricular nucleus neurons.

    Science.gov (United States)

    Zhang, L; Kolaj, M; Renaud, L P

    2015-12-17

    In rat thalamic paraventricular nucleus of thalamus (PVT) neurons, activation of thyrotropin-releasing hormone (TRH) receptors enhances excitability via concurrent decrease in G protein-coupled inwardly-rectifying potassium (GIRK)-like and activation of transient receptor potential cation (TRPC)4/5-like cationic conductances. An exploration of intracellular signaling pathways revealed the TRH-induced current to be insensitive to phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitors, but reduced by D609, an inhibitor of phosphatidylcholine-specific PLC (PC-PLC). A corresponding change in the I-V relationship implied suppression of the cationic component of the TRH-induced current. Diacylglycerol (DAG) is a product of the hydrolysis of PC. Studies focused on the isolated cationic component of the TRH-induced response revealed a reduction by RHC80267, an inhibitor of DAG lipase, the enzyme involved in the hydrolysis of DAG to the endocannabinoid 2-arachidonoylglycerol (2-AG). Further investigation revealed enhancement of the cationic component in the presence of either JZL184 or WWL70, inhibitors of enzymes involved in the hydrolysis of 2-AG. A decrease in the TRH-induced response was noted in the presence of rimonabant or SR144528, membrane permeable CB1 and CB2 receptor antagonists, respectively. A decrease in the TRH-induced current by intracellular, but not by bath application of the membrane impermeable peptide hemopressin, selective for CB1 receptors, suggests a postsynaptic intracellular localization of these receptors. The TRH-induced current was increased in the presence of arachidonyl-2'-chloroethylamide (ACEA) or JWH133, CB1 and CB2 receptor agonists, respectively. The PI3-kinase inhibitor LY294002, known to inhibit TRPC translocation, decreased the response to TRH. In addition, a TRH-induced enhancement of the low-threshold spike was prevented by both rimonabant, and SR144528. TRH had no influence on excitatory or inhibitory miniature

  5. Thalamo–cortical network underlying deep brain stimulation of centromedian thalamic nuclei in intractable epilepsy: a multimodal imaging analysis

    Directory of Open Access Journals (Sweden)

    Kim SH

    2017-10-01

    Full Text Available Seong Hoon Kim,1 Sung Chul Lim,1 Dong Won Yang,1 Jeong Hee Cho,1 Byung-Chul Son,2 Jiyeon Kim,3 Seung Bong Hong,4 Young-Min Shon4 1Department of Neurology, 2Department of Neurosurgery, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, 3Department of Neurology, Korea University Ansan Hospital, College of Medicine, Korea University, Ansan, 4Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea Objective: Deep brain stimulation (DBS of the centromedian thalamic nucleus (CM can be an alternative treatment option for intractable epilepsy patients. Since CM may be involved in widespread cortico-subcortical networks, identification of the cortical sub-networks specific to the target stimuli may provide further understanding on the underlying mechanisms of CM DBS. Several brain structures have distinguishing brain connections that may be related to the pivotal propagation and subsequent clinical effect of DBS.Methods: To explore core structures and their connections relevant to CM DBS, we applied electroencephalogram (EEG and diffusion tensor imaging (DTI to 10 medically intractable patients – three generalized epilepsy (GE and seven multifocal epilepsy (MFE patients unsuitable for resective surgery. Spatiotemporal activation pattern was mapped from scalp EEG by delivering low-frequency stimuli (5 Hz. Structural connections between the CM and the cortical activation spots were assessed using DTI.Results: We confirmed an average 72% seizure reduction after CM DBS and its clinical efficiency remained consistent during the observation period (mean 21 months. EEG data revealed sequential source propagation from the anterior cingulate, followed by the frontotemporal regions bilaterally. In addition, maximal activation was found in the left cingulate gyrus and the right medial frontal cortex during the right and left CM stimulation, respectively

  6. Seizures and Sleep in the Thalamus: Focal Limbic Seizures Show Divergent Activity Patterns in Different Thalamic Nuclei.

    Science.gov (United States)

    Feng, Li; Motelow, Joshua E; Ma, Chanthia; Biche, William; McCafferty, Cian; Smith, Nicholas; Liu, Mengran; Zhan, Qiong; Jia, Ruonan; Xiao, Bo; Duque, Alvaro; Blumenfeld, Hal

    2017-11-22

    The thalamus plays diverse roles in cortical-subcortical brain activity patterns. Recent work suggests that focal temporal lobe seizures depress subcortical arousal systems and convert cortical activity into a pattern resembling slow-wave sleep. The potential simultaneous and paradoxical role of the thalamus in both limbic seizure propagation, and in sleep-like cortical rhythms has not been investigated. We recorded neuronal activity from the central lateral (CL), anterior (ANT), and ventral posteromedial (VPM) nuclei of the thalamus in an established female rat model of focal limbic seizures. We found that population firing of neurons in CL decreased during seizures while the cortex exhibited slow waves. In contrast, ANT showed a trend toward increased neuronal firing compatible with polyspike seizure discharges seen in the hippocampus. Meanwhile, VPM exhibited a remarkable increase in sleep spindles during focal seizures. Single-unit juxtacellular recordings from CL demonstrated reduced overall firing rates, but a switch in firing pattern from single spikes to burst firing during seizures. These findings suggest that different thalamic nuclei play very different roles in focal limbic seizures. While limbic nuclei, such as ANT, appear to participate directly in seizure propagation, arousal nuclei, such as CL, may contribute to depressed cortical function, whereas sleep spindles in relay nuclei, such as VPM, may interrupt thalamocortical information flow. These combined effects could be critical for controlling both seizure severity and impairment of consciousness. Further understanding of differential effects of seizures on different thalamocortical networks may lead to improved treatments directly targeting these modes of impaired function. SIGNIFICANCE STATEMENT Temporal lobe epilepsy has a major negative impact on quality of life. Previous work suggests that the thalamus plays a critical role in thalamocortical network modulation and subcortical arousal

  7. Role of myocardial ischemia on exercise-induced ST elevation

    International Nuclear Information System (INIS)

    Saito, Muneyasu; Sumiyoshi, Tetsuya; Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kouhei; Haze, Kazuo; Fukami, Ken-ichi; Hiramori, Katsuhiko

    1986-01-01

    Exercise-induced ST elevation in patients with previous myocardial infarction (MI) has been recognized to be related to left ventricular (LV) asynergy, however it is also recognized that myocardial ischemia can induce ST elevation. In this study, factors which determine the extent of ST elevation, with special reference to myocardial ischemia, was re-evaluated using quantitative analysis of stress myocardial scintigraphy (S-SG). Among 65 patients with previous anterior myocardial infarction and documented single vessel disease of left anterior descending artery (LAD), 19 patients who had exercise-induced ST elevation (ΔST ≥ 2.0 mm) had more abnormal Q waves (p < 0.01), lower LV ejection fraction (EF) (p < 0.01), more severe LV asynergy (p < 0.05) and less incidence of post-MI angina pectoris (AP) (p < 0.01), compared to those with ΔST < 2.0 mm, indicating that ST elevation is primarily related to LV asynergy. Correlation studies among clinical, angiographic and scintigraphic parameters show that ΔST was significantly related to a size of MI represented by Tl score or relative defect Tl activity and number of abnormal Q waves (No.Q), the magnitude of work load expressed by changes in double product (ΔDP) and intervals between the onset and exercise test, as well as myocardial ischemia expressed by the extent of redistribution (%RD) in S-SG. Among 23 patients with post-MI AP, ΔST significantly correlated with %RD (r = 0.47), indicating that myocardial ischemia can be a mechanism of exercise-induced ST elevation in patients with previous MI. Furtheremore, among those with ST elevation, concave-type ST elevation was more related to myocardial ischemia compared to convex-type ST elevation as expressed by the incidence of post-MI AP and/or significant redistribution. (J.P.N.)

  8. Reperfusion promotes mitochondrial dysfunction following focal cerebral ischemia in rats.

    Directory of Open Access Journals (Sweden)

    Jun Li

    Full Text Available BACKGROUND AND PURPOSE: Mitochondrial dysfunction has been implicated in the cell death observed after cerebral ischemia, and several mechanisms for this dysfunction have been proposed. Reperfusion after transient cerebral ischemia may cause continued and even more severe damage to the brain. Many lines of evidence have shown that mitochondria suffer severe damage in response to ischemic injury. The purpose of this study was to observe the features of mitochondrial dysfunction in isolated mitochondria during the reperfusion period following focal cerebral ischemia. METHODS: Male Wistar rats were subjected to focal cerebral ischemia. Mitochondria were isolated using Percoll density gradient centrifugation. The isolated mitochondria were fixed for electron microscopic examination; calcium-induced mitochondrial swelling was quantified using spectrophotometry. Cyclophilin D was detected by Western blotting. Fluorescent probes were used to selectively stain mitochondria to measure their membrane potential and to measure reactive oxidative species production using flow cytometric analysis. RESULTS: Signs of damage were observed in the mitochondrial morphology after exposure to reperfusion. The mitochondrial swelling induced by Ca(2+ increased gradually with the increasing calcium concentration, and this tendency was exacerbated as the reperfusion time was extended. Cyclophilin D protein expression peaked after 24 hours of reperfusion. The mitochondrial membrane potential was decreased significantly during the reperfusion period, with the greatest decrease observed after 24 hours of reperfusion. The surge in mitochondrial reactive oxidative species occurred after 2 hours of reperfusion and was maintained at a high level during the reperfusion period. CONCLUSIONS: Reperfusion following focal cerebral ischemia induced significant mitochondrial morphological damage and Ca(2+-induced mitochondrial swelling. The mechanism of this swelling may be mediated by

  9. Real time monitoring of rat liver energy state during ischemia.

    Science.gov (United States)

    Barbiro, E; Zurovsky, Y; Mayevsky, A

    1998-11-01

    Hepatic failure is one of the major problems developed during the posttransplantation period. A possible cause of hepatic failure is the prolonged ischemia induced during the implantation procedure. Hepatic ischemia leads to a reduction in oxygen supply, ATP level decline, liver metabolism impairment, and finally organ failure. The purpose of this study was to estimate the functional state of the liver by monitoring liver blood flow and the mitochondrial NADH redox state simultaneously and continuously during in situ liver ischemia followed by reperfusion. Measurements were performed using the multiprobe developed in our laboratory consisting of fibers for the measurement of relative liver blood flow (laser Doppler flowmetry) and mitochondrial redox state (NADH fluorescence). The experimental procedure included the temporary interruption of blood flow to the liver using three types of ischemia, hepatic artery occlusion, portal vein occlusion, and simultaneous occlusion of hepatic artery and portal vein, followed by a reperfusion period. These preliminary experiments showed a significant decrease in liver blood flow, following the three types of liver ischemia, and a significant increase in NADH levels. The probe used in this study incorporates the advantage of monitoring NADH and liver blood flow simultaneously and continuously from the same area on the surface of the liver. Since each of these two parameters is not calibrated in absolute units, the simultaneous monitoring decreases possible artifacts. Also, it will allow us to determine of the coupling between tissue blood flow and oxidative phosphorylation. It is believed that the measurements of respiratory chain dysfunction might predict organ viability in clinical organ transplantation situations. Using this probe may also help to decrease the variability in liver blood flow monitoring since liver blood flow monitoring is supported simultaneously with the mitochondrial redox state, which supplies the

  10. Acute limb ischemia in cancer patients: should we surgically intervene?

    LENUS (Irish Health Repository)

    Tsang, Julian S

    2012-02-01

    BACKGROUND: Cancer patients have an increased risk of venous thromboembolic events. Certain chemotherapeutic agents have also been associated with the development of thrombosis. Reported cases of acute arterial ischemic episodes in cancer patients are rare. METHODS: Patients who underwent surgery for acute limb ischemia associated with malignancy in a university teaching hospital over a 10-year period were identified. Patient demographics, cancer type, chemotherapy use, site of thromboembolism, treatment and outcome were recorded. RESULTS: Four hundred nineteen patients underwent surgical intervention for acute arterial ischemia, 16 of these patients (3.8%) had associated cancer. Commonest cancer sites were the urogenital tract (n = 5) and the lungs (n = 5). Eight patients (50%) had been recently diagnosed with cancer, and four (25%) of these cancers were incidental findings after presentation with acute limb ischemia. Four patients (25%) developed acute ischemia during chemotherapy. The superficial femoral artery was the most frequent site of occlusion (50%), followed by the brachial (18%) and popliteal (12%) arteries. All patients underwent thromboembolectomy, but two (12%) patients subsequently required a bypass procedure. Six patients (37%) had limb loss, and in-patient mortality was 12%. Histology revealed that all occlusions were due to thromboembolism, with no tumor cells identified. At follow-up, 44% of patients were found to be alive after 1 year. CONCLUSION: Cancer and chemotherapy can predispose patients to acute arterial ischemia. Unlike other reports that view this finding as a preterminal event most appropriately treated by palliative measures, in this series, early diagnosis and surgical intervention enabled limb salvage and patient survival.

  11. Diagnostic Value of Procalcitonin Levels in Acute Mesenteric Ischemia

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    Yunus Karaca

    2015-09-01

    Full Text Available Background: Acute mesenteric ischemia (AMI is a potentially fatal disease. Difficulties in diagnosis make it essential to find early biomarkers. Aims: This study investigated the diagnostic value of procalcitonin (PCT levels in AMI. Study Design: Animal experimentation. Methods: Rats were divided into six groups of six animals each. In the experimental group, an experimental ischemia model was established by clamping the superior mesenteric artery from the aortic outflow tract. Blood and tissue specimens were collected from rats in the experimental mesenteric ischemia model at 30 min and 2 and 6 h, and these were compared with specimens from the respective control groups. PCT levels were compared at 30 min and 2 and 6 h. Results: PCT levels were 185.3 pg/mL in the control group and 219.3 pg/mL in the study group, 199.6 pg/mL in the control group and 243.9 pg/mL in the study group, and 201.9 pg/mL in the control group and 286.9 pg/mL in the study group, respectively, at 30 minute, 2 and 6 hours. Significant differences were determined between 6-h control group and ischemia group PCT levels (p=0.005. Conclusion: The absence of a significant increase in PCT levels in the early period, while a significant difference was detected in the later period (6 h, shows that PCT levels rise late in mesenteric ischemia and can be a marker in the late period.

  12. Reversed field pinch diagnostics

    International Nuclear Information System (INIS)

    Weber, P.G.

    1986-01-01

    The Reversed Field Pinch (RFP) is a toroidal, axisymmetric magnetic confinement configuration characterized by a magnetic field configuration in which the toroidal magnetic field is of similar strength to the poloidal field, and is reversed at the edge compared to the center. The RFP routinely operates at high beta, and is a strong candidate for a compact fusion device. Relevant attributes of the configuration will be presented, together with an overview of present and planned experiments and their diagnostics. RFP diagnostics are in many ways similar to those of other magnetic confinement devices (such as tokamaks); these lectures will point out pertinent differences, and will present some diagnostics which provide special insights into unique attributes of the RFP

  13. Posterior Reversible Encephalopathy (PRES)

    International Nuclear Information System (INIS)

    Moron E, Fanny E; Diaz Marchan, Pedro

    2005-01-01

    The Posterior Reversible Encephalopathy Syndrome (PRES) is a clinical Syndrome composed of cephalea, alteration in vision and convulsions, usually observed in patients with sudden elevation of arterial pressure. The imagenologic evidence shows reversible vasogenic brain edema without stroke. Its location is predominantly posterior; it affects the cortex and the subcortical white matter of the occipital, parietal and temporal lobes. The treatment with antihypertensive drugs and the removing of immunosupressor medication are generally associated with complete neurological recovery; this is reflected also in the images which return to their basal condition. The untreated hypertension, on the other side, can result in a progressive defect of the autoregulation system of the central nervous system with cerebral hemorrhage, irreversible brain stroke, coma and death

  14. CT perfusion imaging in the management of posterior reversible encephalopathy

    International Nuclear Information System (INIS)

    Casey, S.O.; McKinney, A.; Teksam, M.; Liu, H.; Truwit, C.L.

    2004-01-01

    A 13-year-old girl with a renal transplant presented with hypertension and seizures. CT and MRI demonstrated typical bilateral parietal, occipital and posterior frontal cortical and subcortical edema, thought to represent posterior reversible encephalopathy syndrome. The cause was presumed to be hypertension. Antihypertensive therapy was started, lowering of the blood pressure in the range of 110-120 mmHg systolic. However, stable xenon (Xe) CT perfusion imaging revealed ischemia within the left parietal occipital region. The antihypertensive was adjusted which increased both the systolic and diastolic blood pressure by 31 mm Hg. The patient was re-imaged with Xe CT and was found to have resolution of the ischemic changes within the left parietal occipital region. In this report, we present a case in which stable Xe CT was used to monitor the degree of cerebral perfusion and guide titration of antihypertensive therapy. Such brain perfusion monitoring may have helped to prevent infarction of our patient. (orig.)

  15. Sevoflurane postconditioning improves myocardial mitochondrial respiratory function and reduces myocardial ischemia-reperfusion injury by up-regulating HIF-1.

    Science.gov (United States)

    Yang, Long; Xie, Peng; Wu, Jianjiang; Yu, Jin; Yu, Tian; Wang, Haiying; Wang, Jiang; Xia, Zhengyuan; Zheng, Hong

    2016-01-01

    Sevoflurane postconditioning (SPostC) can exert myocardial protective effects similar to ischemic preconditioning. However, the exact myocardial protection mechanism by SPostC is unclear. Studies indicate that hypoxia-inducible factor-1 (HIF-1) maintains cellular respiration homeostasis by regulating mitochondrial respiratory chain enzyme activity under hypoxic conditions. This study investigated whether SPostC could regulate the expression of myocardial HIF-1α and to improve mitochondrial respiratory function, thereby relieving myocardial ischemia-reperfusion injury in rats. The myocardial ischemia-reperfusion rat model was established using the Langendorff isolated heart perfusion apparatus. Additionally, postconditioning was performed using sevoflurane alone or in combination with the HIF-1α inhibitor 2-methoxyestradiol (2ME2). The changes in hemodynamic parameters, HIF-1α protein expression levels, mitochondrial respiratory function and enzyme activity, mitochondrial reactive oxygen species (ROS) production rates, and mitochondrial ultrastructure were measured or observed. Compared to the ischemia-reperfusion (I/R) group, HIF-1α expression in the SPostC group was significantly up-regulated. Additionally, cardiac function indicators, mitochondrial state 3 respiratory rate, respiratory control ratio (RCR), cytochrome C oxidase (C c O), NADH oxidase (NADHO), and succinate oxidase (SUCO) activities, mitochondrial ROS production rate, and mitochondrial ultrastructure were significantly better than those in the I/R group. However, these advantages were completely reversed by the HIF-1α specific inhibitor 2ME2 ( P <0.05). The myocardial protective function of SPostC might be associated with the improvement of mitochondrial respiratory function after up-regulation of HIF-1α expression.

  16. Clinical evaluation of adenosine and exercise stress 99Tcm-MIBI myocardial imaging in detection of myocardial ischemia in patients with untypical chest pain

    International Nuclear Information System (INIS)

    Tian Yueqin; He Zuoxiang; Wang Qi; Hu Fenghuan; Yang Weixian; Qiao Shubing; Liu Xiujie

    2005-01-01

    Objective: To evaluate the value of adenosine and exercise stress 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial imaging for the diagnosis of myocardial ischemia in patients with untypical chest pain. Methods: Two groups included. Group 1: 67 cases of adenosine 99 Tc m -MIBI myocardial imaging. Group 2: 81 cases of exercise stress 99 Tc m -MIBI myocardial imaging. All of the patients had coronary angiography (CAG). The results of them were compared. Results: 23 out of 67 patients in group 1 had significant coronary stenosis after CAG, 16 showed reversible perfusion abnormalities in adenosine imaging. 41 of 44 patients with normal CAG showed normal adenosine imaging. The sensitivity, specificity and accuracy of adenosine imaging for coronary artery disease detection were 70%, 93% and 85%, respectively. Group 2: 22 out of 31 patients with significant coronany stenosis after CAG showed reversible perfusion abnormalities, 48 of 50 patients with normal CAG showed normal exercise imaging. The sensitivity, specificity and accuracy of exercise imaging for coronary artery disease detection were 71%, 96% and 86%, respectively. Conclusion: Reversible perfusion abnormalities found both in adenosine and exercise stress 99 Tc m -MIBI myocardial imaging were the key point for diagnosis of myocardial ischemia in patients with untypical chest pain. (authors)

  17. Reversible infantile mitochondrial diseases.

    Science.gov (United States)

    Boczonadi, Veronika; Bansagi, Boglarka; Horvath, Rita

    2015-05-01

    Mitochondrial diseases are usually severe and progressive conditions; however, there are rare forms that show remarkable spontaneous recoveries. Two homoplasmic mitochondrial tRNA mutations (m.14674T>C/G in mt-tRNA(Glu)) have been reported to cause severe infantile mitochondrial myopathy in the first months of life. If these patients survive the first year of life by extensive life-sustaining measures they usually recover and develop normally. Another mitochondrial disease due to deficiency of the 5-methylaminomethyl-2-thiouridylate methyltransferase (TRMU) causes severe liver failure in infancy, but similar to the reversible mitochondrial myopathy, within the first year of life these infants may also recover completely. Partial recovery has been noted in some other rare forms of mitochondrial disease due to deficiency of mitochondrial tRNA synthetases and mitochondrial tRNA modifying enzymes. Here we summarize the clinical presentation of these unique reversible mitochondrial diseases and discuss potential molecular mechanisms behind the reversibility. Understanding these mechanisms may provide the key to treatments of potential broader relevance in mitochondrial disease, where for the majority of the patients no effective treatment is currently available.

  18. Positioning paper on reversibility

    International Nuclear Information System (INIS)

    2016-01-01

    After having recalled the legal framework adopted in 2006 for the deep geological storage of radioactive wastes, and briefly introduced the concept of reversibility, this publication presents the principle of geological storage, presents high and medium level and long life wastes, highlights the ethical necessity to deal with these radioactive wastes, outlines that geological storage is the generally admitted and adopted solution at the international level, and presents additional means implemented for radioactive waste management. It presents the Cigeo project as the technical answer to the issue of radioactive waste storage, describes the Cigeo development process, its current status and its development planning, and justifies the choice of this technical solution, notably from an ethical point of view. It addresses the issue of reversibility and proposes an overview of the various tools and means which aim at guaranteeing this reversibility. Appendices propose figures illustrating the Cigeo project and its development process, and a rather detailed Power Point presentation of the project by the ANDRA (history, object, planning, installations, and so on)

  19. The effect of unilateral thalamic deep brain stimulation on the vocal dysfunction in a patient with spasmodic dysphonia: interrogating cerebellar and pallidal neural circuits.

    Science.gov (United States)

    Poologaindran, Anujan; Ivanishvili, Zurab; Morrison, Murray D; Rammage, Linda A; Sandhu, Mini K; Polyhronopoulos, Nancy E; Honey, Christopher R

    2018-02-01

    Spasmodic dysphonia (SD) is a neurological disorder of the voice where a patient's ability to speak is compromised due to involuntary contractions of the intrinsic laryngeal muscles. Since the 1980s, SD has been treated with botulinum toxin A (BTX) injections into the throat. This therapy is limited by the delayed-onset of benefits, wearing-off effects, and repeated injections required every 3 months. In a patient with essential tremor (ET) and coincident SD, the authors set out to quantify the effects of thalamic deep brain stimulation (DBS) on vocal function while investigating the underlying motor thalamic circuitry. A 79-year-old right-handed woman with ET and coincident adductor SD was referred to our neurosurgical team. While primarily treating her limb tremor, the authors studied the effects of unilateral, thalamic DBS on vocal function using the Unified Spasmodic Dysphonia Rating Scale (USDRS) and voice-related quality of life (VRQOL). Since dystonia is increasingly being considered a multinodal network disorder, an anterior trajectory into the left thalamus was deliberately chosen such that the proximal contacts of the electrode were in the ventral oralis anterior (Voa) nucleus (pallidal outflow) and the distal contacts were in the ventral intermediate (Vim) nucleus (cerebellar outflow). In addition to assessing on/off unilateral thalamic Vim stimulation on voice, the authors experimentally assessed low-voltage unilateral Vim, Voa, or multitarget stimulation in a prospective, randomized, doubled-blinded manner. The evaluators were experienced at rating SD and were familiar with the vocal tremor of ET. A Wilcoxon signed-rank test was used to study the pre- and posttreatment effect of DBS on voice. Unilateral left thalamic Vim stimulation (DBS on) significantly improved SD vocal dysfunction compared with no stimulation (DBS off), as measured by the USDRS (p dysphonia. A Phase 1 pilot trial (DEBUSSY; clinical trial no. NCT02558634, clinicaltrials.gov) is

  20. Clinical significance of 201Tl reverse redistribution in patients with aorto-coronary bypass surgery

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Uehara, Tashiisa; Hayashida, Kohei; Kozuka, Takahira

    1987-01-01

    Detection of myocardial ischemia by the stress thallium scan has traditionally been performed using transient defect analysis on exercise, followed by redistribution studies. Worsening of the 201 Tl myocardial image from exercise to redistribution is referred to as reverse redistribution. In this study, we found reverse redistribution in 10 (21%) of 48 angina pectoris patients who had undergone aortocoronary bypass surgery. The clinical significance of this phenomenon in these patients was investigated in relation to angiographic and surgical findings. Reverse redistribution was found to occur in regions which were supplied by bypass grafts. These areas showed increased coronary blood flow and rapid thallium washout. Our results indicate that a perfusion defect in the bypass region of the redistribution image might be caused by relatively rapid washout in the bypass graft region compared to the adjacent normal myocardium. These results should be considered in the clinical interpretation of stress thallium scans. (orig.)

  1. Efficacy of T2*-Weighted Gradient-Echo MRI in Early Diagnosis of Cerebral Venous Thrombosis with Unilateral Thalamic Lesion

    Directory of Open Access Journals (Sweden)

    Shingo Mitaki

    2013-01-01

    Full Text Available Cerebral venous thrombosis (CVT is an uncommon cause of stroke with diverse etiologies and varied clinical presentations. Because of variability in clinical presentation and neuroimaging, CVT remains a diagnostic challenge. Recently, some studies have highlighted the value of T2*-weighted gradient-echo MRI (T2*WI in the diagnosis of CVT. We report the case of a 79-year-old woman with CVT due to a hypercoagulable state associated with cancer. On the initial T2-weighted image (T2WI, there was a diffuse high-intensity lesion in the right thalamus, extending into the posterior limb of the internal capsule and midbrain. T2*WI showed diminished signal and enlargement of the right basilar vein and the vein of Galen. Even though there is a wide range of differential diagnoses in unilateral thalamic lesions, and a single thalamus lesion is a rare entity of CVT, based on T2*WI findings we could make an early diagnosis and perform treatment. Our case report suggests that T2*WI could detect thrombosed veins and be a useful method of early diagnosis in CVT.

  2. Resolving the detailed structure of cortical and thalamic neurons in the adult rat brain with refined biotinylated dextran amine labeling.

    Science.gov (United States)

    Ling, Changying; Hendrickson, Michael L; Kalil, Ronald E

    2012-01-01

    Biotinylated dextran amine (BDA) has been used frequently for both anterograde and retrograde pathway tracing in the central nervous system. Typically, BDA labels axons and cell somas in sufficient detail to identify their topographical location accurately. However, BDA labeling often has proved to be inadequate to resolve the fine structural details of axon arbors or the dendrites of neurons at a distance from the site of BDA injection. To overcome this limitation, we varied several experimental parameters associated with the BDA labeling of neurons in the adult rat brain in order to improve the sensitivity of the method. Specifically, we compared the effect on labeling sensitivity of: (a) using 3,000 or 10,000 MW BDA; (b) injecting different volumes of BDA; (c) co-injecting BDA with NMDA; and (d) employing various post-injection survival times. Following the extracellular injection of BDA into the visual cortex, labeled cells and axons were observed in both cortical and thalamic areas of all animals studied. However, the detailed morphology of axon arbors and distal dendrites was evident only under optimal conditions for BDA labeling that take into account the: molecular weight of the BDA used, concentration and volume of BDA injected, post-injection survival time, and toning of the resolved BDA with gold and silver. In these instances, anterogradely labeled axons and retrogradely labeled dendrites were resolved in fine detail, approximating that which can be achieved with intracellularly injected compounds such as biocytin or fluorescent dyes.

  3. The short- and long-term proteomic effects of sleep deprivation on the cortical and thalamic synapses.

    Science.gov (United States)

    Simor, Attila; Györffy, Balázs András; Gulyássy, Péter; Völgyi, Katalin; Tóth, Vilmos; Todorov, Mihail Ivilinov; Kis, Viktor; Borhegyi, Zsolt; Szabó, Zoltán; Janáky, Tamás; Drahos, László; Juhász, Gábor; Kékesi, Katalin Adrienna

    2017-03-01

    Acute total sleep deprivation (SD) impairs memory consolidation, attention, working memory and perception. Structural, electrophysiological and molecular experimental approaches provided evidences for the involvement of sleep in synaptic functions. Despite the wide scientific interest on the effects of sleep on the synapse, there is a lack of systematic investigation of sleep-related changes in the synaptic proteome. We isolated parietal cortical and thalamic synaptosomes of rats after 8h of total SD by gentle handling and 16h after the end of deprivation to investigate the short- and longer-term effects of SD on the synaptic proteome, respectively. The SD efficiency was verified by electrophysiology. Protein abundance alterations of the synaptosomes were analyzed by fluorescent two-dimensional differential gel electrophoresis and by tandem mass spectrometry. As several altered proteins were found to be involved in synaptic strength regulation, our data can support the synaptic homeostasis hypothesis function of sleep and highlight the long-term influence of SD after the recovery sleep period, mostly on cortical synapses. Furthermore, the large-scale and brain area-specific protein network change in the synapses may support both ideas of sleep-related synaptogenesis and molecular maintenance and reorganization in normal rat brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction

    International Nuclear Information System (INIS)

    Nabatame, Hidehiko; Nakamura, Kazuo; Matsuda, Minoru; Fujimoto, Naoki; Fukuyama, Hidenao.

    1995-01-01

    We performed MRI and measured cerebral blood flow (CBF) using 123 I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p<0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p<0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction. (author)

  5. Occipital transtentorial/falcine approach, a "cross-court" trajectory to accessing contralateral posterior thalamic lesions: case report.

    Science.gov (United States)

    Iwami, Kenichiro; Fujii, Masazumi; Saito, Kiyoshi

    2017-07-01

    Surgical treatment of lesions in the posterior thalamus, especially those extending laterally, is technically challenging because of a deep surgical field, narrow operative corridor, and the surrounding critical neurovascular structures. The authors describe an occipital transtentorial/falcine approach (OTFA) that was successfully used in the tr