Irregular and uncontrollable flinging movements of the arm and leg on 1 side of the body, caused by disease of the basal ganglia. (See also athetosis; chorea.)
Involuntary movements similar to choreiform (see CHOREA) movements, but of much greater amplitude and force. The violent, throwing movements of the limbs are usually unilateral, and tend to occur acutely as a result of vascular damage to the mid-brain.
n. violent repetitive involuntary movements particularly involving the proximal limbs. They occur following bilateral damage to the *subthalamic nuclei of the basal ganglia, most commonly after stroke, haemorrhage, or trauma. In hemiballismus, only one side of the body is affected due to contralateral subthalamic dysfunction.... ballism
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