title: Alterations of cortical excitability and central motor conduction time in Wilson's disease.
abstract: Wilson's disease (WD) leads to widespread structural alterations of central nervous system and our objectives were to determine the cortical excitability changes in WD by using transcranial magnetic stimulation (TMS). Thirteen patients with WD, diagnosed by the presence of Kayser-Fleischer ring and biochemical tests, were studied. TMS was performed using a figure-of-eight coil attached to Magstim 200 stimulator. Motor evoked potentials (MEP) were recorded from right first dorsal interosseous at rest. Resting motor threshold (RMT) was determined using standard techniques and central motor conduction time (CMCT) by 'F' wave method. Comparison was made with control data of our laboratory. Dysarthria was the presenting symptom in 5 patients (38.5%) and chorea, tremors, dystonia and abnormal gait in 2 patients each (15.4%). RMT was recordable in 10 patients and not recordable in 3. Compared to controls, patients in whom RMT was recordable, had significantly higher mean RMT (80.9 ± 14.8 vs. 41.1 ± 7, p<0.0001) and CMCT (6.7 ± 0.5 ms vs. 4.8 ± 0.6 ms; p<0.0001). In 2 of the 3 patients with non-recordable RMT, MEP could be obtained with active contraction. CMCT in these 2 patients was also prolonged. Patients with WD have reduced cortical excitability and prolonged CMCT which may be due to the intracortical presynaptic motor dysfunction.
authors: Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore 560029, Karnataka, India.
authors: Ketan
authors: K
authors: Jhunjhunwala
authors: D K
authors: DK
authors: Prashanth
authors: M
authors: M
authors: Netravathi
authors: B C
authors: BC
authors: Nagaraju
authors: Pramod Kr
authors: PK
authors: Pal
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D019054:Evoked Potentials, Motor; D005260:Female; D006527:Hepatolenticular Degeneration / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010396:Penicillamine / Q000627:therapeutic use; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult; D019287:Zinc Sulfate / Q000627:therapeutic use
chemical_list: D019287:Zinc Sulfate; D010396:Penicillamine
keywords: Central motor conduction time; Cortical excitability; Resting motor threshold; Transcranial magnetic stimulation; Wilson's disease