[Unilateral asterixis after hemiballism in a patient with acute cerebral infarction]

An-88-year-old right-handed female complained of repeated intermittent hemiballism in the right upper and lower extremities. She presented to our hospital with monoparesis and asterixis of the right arm, but not hemiballism. Brain MRI revealed acute disseminated cerebral infarctions in the middle cerebral artery watershed area of the left hemisphere, including the striatum and cortical areas. Occlusion of the left internal carotid artery was also detected. She was diagnosed as acute cerebral infarction and received intravenous infusion, after which her neurological symptoms gradually improved. We presumed that the intermittent hemiballism was related to dysfunction of the motor loop induced by circulatory insufficiency in the left striatum, and that unilateral asterixis might be induced by hemodynamic hypoperfusion in the left frontal lobe. The hemodynamic changes induced by occlusion of the left internal carotid artery might be associated with pathogenesis of these involuntary movements.