Choreoballismus: a nonhemorrhagic complication of venous angiomas.

Choreoballismus, developing subacutely in a 48-year-old man, is reported for the first time as a complication of a cerebral venous angioma, demonstrated by computed tomography scanning and angiography. There was no apparent hemorrhage or mass effect from the angioma, which was located in the right caudate nucleus. The movement disorder, which did not respond to haloperidol alone, disappeared after the addition of clonazepam. The necessity for dual therapy implies that there was a disorder of more than one neurotransmitter system in this patient. The clinical and pathological features of these unusual vascular malformations are reviewed.