hemiballismus
Pronunciation: hem-ee-bah-LIZ-mus
Violent, involuntary flinging movements affecting one side of the body, typically from subthalamic nucleus lesions.
Full Definition
Hemiballismus is a rare hyperkinetic movement disorder characterized by sudden, violent, involuntary flinging or throwing movements that typically affect one side of the body (hemiballismus) or, rarely, both sides (ballismus). The movements are large-amplitude, irregular, and can be so severe as to cause injury or prevent normal activities. This condition most commonly results from lesions in the subthalamic nucleus, often due to stroke, but can also occur with other structural lesions, metabolic disorders, or as a side effect of certain medications. The movements may persist during sleep in severe cases.
Usage
Usage note: Sometimes shortened to 'ballismus' when bilateral; specify laterality when unilateral.
In Context
- "Hemiballismus developed acutely following the subthalamic nucleus stroke." — Emergency neurology consultation
- "The patient's hemiballismus gradually improved with haloperidol treatment." — Movement disorder treatment response