Hemiballismus

Hemiballismus is a hyperkinetic involuntary movement disorder characterized by intermittent, sudden, violent, involuntary, flinging, or ballistic high amplitude movements involving the ipsilateral arm and leg caused by dysfunction in the central nervous system of the contralateral side. Hemiballismus falls as the most severe form within the spectrum of chorea. Chorea is an involuntary movement disorder characterized by brief, sudden, spontaneous, non-stereotyped, and dance-like movements in one side of the body. The classic medical school textbook localizes the lesion to the subthalamic nucleus (STN) or the nucleus hypothalamicus/corpus Luys; however, other research also localizes the lesions in other parts of the basal ganglia and caudate nucleus.