Familial arteriovenous malformations of the brain--two case reports.

Familial arteriovenous malformation (AVM) of the brain is an uncommon entity. A 24-year-old female presented with sudden onset of left hemiparesis due to an AVM with a hematoma in the right frontal lobe, which was surgically removed. Her 23-year-old younger sister presented with motor aphasia and right hemiparesis due to an AVM with a hematoma in the left frontoparietal lobes, which was surgically removed. Thirty-two patients in 15 families have been described in total. The mean age of these patients was 28 years, with 15 males and 17 females. Multiple AVMs occurred in four patients (12.5%), more frequently than in non-familial cases.