[Ballism, hemiballism].

Ballism, which is seen relatively infrequently among movement disorders, is characterized by the abrupt onset of vigorous, rapidly executed, poorly patterned in voluntary movement of the limbs. Hemiballism is mostly associated with the lesion in the subthalamic nucleus. However, it occasionally occurs as a result of lesions outside the subthalamic nucleus. The natural history of hemiballism caused by vascular subthalamic lesion usually shows gradual disappearance within days or weeks. Death from exhaustion has however been reported in some patients within four to six weeks after the onset. Hemiballism caused by lesions outside the subthalamic nucleus tends to persist for a longer period. Intensive treatment is therefore required. Successful treatments of hemiballism with haloperidol or chlorpromazine are wellknown, but, in older patients, sulpiride can be the first choice of medications because of its lesser side effect.