A Case of Hemiballism

ABSTRACT

Hemiballism is a ballistic, involuntary movement disorder, usually of a sudden onset, an often occurs due to encephalomalasic lesion, mostly an infarction, of deep structure of contralateral cerebral hemisphere, rarely by a small hemorrhage. The lesion site is thought to be mainly subthalamic nucleus contralateral to the abnormal movement. But there have been several reports on hemiballism without involvement of subthalmic nucleus throughout the world. We report a case of acute vascular hemiballism occurred due to a small hemorrhage with involvement of left putamen and globus pallidus, which was demonstrated by computed tomography and magnetic resonance imaging study of brain.