Suppressive effect on focal upper extremity dystonia after repetitive 1Hz transcranial magnetic stimulation

We had the patient with dystonia of proximal part of upper extremity. The magnetic transcranial stimulation (TMS) finding showed abnormal regulation of cortical motor control system, which could suggest more activation in cortical motor facilitation or less activation of cortical inhibition system. The finding of functional magnetic resonance imaging (fMRI) showed less activation of left motor area than right motor area followed by finger tapping task. Both TMS and fMRI could suggest dysfunction of cortical inhibitory system. rTMS treatment on left motor cortex had acute effect of involuntary movement. After treatment, over-activity or dystonic activity of right arm was decreased and voluntary movement had been improved. Our study showed fMRI study and TMS could reveal the less motor cortical inhibition mechanism, and also showed rTMS can have some effect on focal upper extremity dystonia.