[Ballism as a rare form of hyperkinetic movement disorder]

Hemiballism is a very rare movement disorderthat presents with involuntary unilateral flinging movements of the limbs. The movements are often violent and have wide amplitudes of motion. Hemichorea and hemiballism share pathophysiology and etiology, and commonly coexist in the same patient. Hemiballism was recognised as almost pathognomonic of a lesion in the contralateral subthalamic nucleus (body of Luys). Cerebrovascular diseases remain the most common etiology of ballistic movements. Interestingly, nowadays nonketotic hyperglycemiain elderly patients with diabetes mellitus is considered to be the second most common reported cause. Other more rare causes of hemiballism include encephalitis, cerebral toxoplasmosis (AIDS), multiple sclerosis, brain tumor (primary, metastatic) and metabolic disturbances. Prognosis is favorable for most patients with spontaneous resolution of clinical symptoms and dopamine receptor blocking drugs are highly effective.