Alterations of cortical excitability and central motor conduction time in Wilson's disease

•In Wilson's disease (WD) there are structural alterations of brain.•Transcranial magnetic stimulation (TMS) can evaluate neurophysiological changes.•Thirteen patients with WD were studied using TMS.•Non-recordable or high RMT and prolonged CMCT were observed in WD.•Patients with WD have widespread changes of cortical excitability. 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