Risperidone-responsive segmental dystonia and pallidal deep brain stimulation.

A 67-year-old man with risperidone-responsive segmental dystonia underwent bilateral deep brain stimulation (DBS) of the globus pallidus internus. Prospectively, the authors assessed the Burke-Fahn-Marsden Dystonia Rating Scale in medication (M) and stimulation (S) "on"/"off" states. With DBS at 9 months, the score improved by 86% to 8.5 in M-"on"/S-"on" and 12.5 in M-"off"/S-"on." Studies of the effects of DBS and concomitant medication may be warranted in selected patients treated by DBS for dystonia.