Cortical excitability in myoclonus-dystonia with Epsilon-Sarcoglycan gene (SGCE) mutation

Abstract

Myoclonus-dystonia (M-D) is a movement disorders with both involuntary jerks and dystonic contractions. Although some studies have shown an abnormal cortical excitability in patients with dystonia and myoclonus, respectively, there is no electrophysiological study in patients with M-D with SGCE mutation. The objective of the study was to investigate the physiological role of the motor cortex in patients with M-D with SGCE mutation, in an attempt to obtain an insight into the mechanisms possible for the pathophysiology of M-D. Method : We applied the transcranial magnetic stimulation (TMS) techniques previously used in DYT1 dystonia (Edwards et al., 2003) to a group of six M-D patients (3 males and 3 females, aged 23-54 years) and ten age-matched healthy controls. Assessments of motor cortex excitability included resting and active threshold, cortical silent period (CSP), and intracortical inhibition and facilitation using a paired-pulse TMS technique. Data were subjected to one-way ANOVA. Post hoc analysis was performed by means of Student`s t-test.