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Interhemispheric Differences (interhemispheric + difference)
Selected AbstractsHemifacial spasm or somatoform disorder , postexcitatory inhibition after transcranial magnetic cortical stimulation asa diagnostic toolACTA NEUROLOGICA SCANDINAVICA, Issue 5 2000S. Kotterba Hemifacial spasm (HFS) presents a frequent movement disorder. It is thought to have an organic origin. It therefore has to be distinguished from other facial involuntary movements, especially psychogenic tics, because the therapeutic approach differs. The present study opted to evaluate the diagnostic value of the postexcitatory inhibition (pI) after transcranial magnetic stimulation (TMS). After stimulating the contralateral hemisphere with the conventional flat coil and recording from the mentalis muscle, in 10 healthy controls and 10 patients postexcitatory inhibition was determined. PI showed no side to side difference in healthy controls (96.9±12.7 ms right, 87.9±10.8 ms left side, interhemispheric difference 6.4±3.8 ms). In 8 patients with hemifacial spasm, the duration of pI on the non-affected side did not differ from the healthy controls (87.9±43.5 ms). During spasm, pI on the affected side shortened increasingly until no inhibition could be induced. Afterwards the spasm pI was prolonged significantly (up to 140 ms longer than opposite side) before returning to normal values. Two patients presented no side differences of pI during the "spasm". An emotional conflict situation could be evaluated, supporting the diagnosis of somatoform disorder. As postexcitatory inhibition is mainly due to cerebral mechanisms, the electrophysiological results of the study pointed to a cortical influence on the hemifacial spasm. TMS seems to be an electrophysiological tool which allows a differentiation between organic and psychogenic spasm and enables a different therapeutic approach. [source] Effects of escitalopram on the regulation of brain-derived neurotrophic factor and nerve growth factor protein levels in a rat model of chronic stressJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2009Olaf Schulte-Herbrüggen Abstract Escitalopram (ES-CIT) is a widely used, highly specific antidepressant. Until now there has been very little evidence on how this drug under pathological conditions affects an important feature within the pathophysiology of stress-related disorders such as depression: the endogenous neurotrophins. By using a well-characterized rat model in which chronic stress induces depressive-like behavior, the levels of neurotrophins brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were determined in representative brain regions and serum using a highly sensitive improved fluorometric two-site ELISA system. There was a significant increase of BDNF in the left and right cortices after stress treatment (twofold increase) that was reversed by application of ES-CIT. An ES-CIT-dependent NGF reduction in stressed rats was detectable in the right cortex only (P = 0.027). The left hippocampus revealed significantly higher amounts of BDNF (2.5-fold increase) protein than the right hippocampus. These interhemispheric differences were unrelated to stress or ES-CIT treatment in all animals. BDNF and NGF of the frontal cortex, cerebellum, and serum did not change between the study groups. There was a negative correlation between body weight and serum BDNF, independent of stress or ES-CIT treatment. In conclusion, BDNF and NGF show substantial changes in this rodent model of chronic social stress, which is susceptible to antidepressant treatment with ES-CIT and therefore may constitute a neurobiological correlate for the disease. © 2009 Wiley-Liss, Inc. [source] The relationship between regional cerebral blood flow and the Wisconsin Card Sorting Test in negative schizophreniaPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 1 2002Zhening Liu MD Abstract The purpose of this study was to explore the relationship between regional cerebral blood flow (rCBF) and problem-solving thinking in negative schizophrenia. Twenty-one negative schizophrenic patients and 12 normal controls were studied with single photon emission computed tomography (SPECT). Measures of regional cerebral blood flow (rCBF) were taken both at rest and during a prefrontal activation task using Wisconsin Card Sorting Test (WCST). Compared with controls, poor performances on the WCST of total trials category (TT), perseverative errors (PE) and non-perseverative errors (NE) were found in negative schizophrenic (P < 0.05). During WCST activation, patients showed interhemispheric differences in the prefrontal region, but under rest conditions, no such differences manifested. The negative schizophrenia group had a significantly lower rCBF change rate in profrontal lobe during stimulant WCST than those in normal controls (P < 0.05). The negative schizophrenic patient has executive function deficits and lower rCBF perfusion in left profrontal lobes, which suggest that the negative schizophrenic patient has dysfunction of the left profrontal region. [source] The clinical and neuroimaging studies in Holmes tremorACTA NEUROLOGICA SCANDINAVICA, Issue 5 2010A. Gajos Gajos A, Bogucki A, Schinwelski M, So,tan W, Rudzi,ska M, Budrewicz S, Koszewicz M, Majos A, Górska-Chrz,stek M, Bie,kiewicz M, Ku,mierek J, S,awek J. The clinical and neuroimaging studies in Holmes tremor. Acta Neurol Scand: 2010: 122: 360,366. © 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Aim,,, Holmes tremor (HT) is a combination of rest, postural and action tremor. A parallel dysfunction of cerebello-thalamic and nigrostriatal pathways seems necessary to produce this kind of tremor. We present the clinical and neuroimaging study verifying that hypothesis. Material and methods,,, A total of 10 patients: five male, five female, fulfilling consensus criteria were included. Demographic, clinical and neuroimaging data (MRI = 9; CT = 1, SPECT with the use of 123-I-FP CIT: DaTSCAN in six patients to assess the presynaptic dopaminergic nigrostriatal system involvement, indices of asymmetry for ligand uptake for each striatum were calculated) were analyzed. Results,,, Hemorrhage was the most frequent etiology and thalamus , the most commonly involved structure. Contrary to the previous reports, the visual assessment did not reveal remarkable interhemispheric differences of DaTSCAN uptake. Quantitative measurements showed only minimal differences. Conclusions,,, It is open to debate whether nigrostriatal pathway damage is crucial for the phenomenology of HT. Alternative hypothesis is presented that HT represents the heterogeneous spectrum of tremors with similar phenomenology, but different pathophysiology. [source] | ||||||||||