Abstract
A 36-year-old male presented with aphasia and right hemiparesis due to the rupture of the larger of two arteriovenous malformations (AVMs) coexisting in the left hemisphere. The two AVMs had completely separate locations and different feeding arteries and draining systems. Two months after resection of the larger AVM and evacuation of the hematoma, carotid angiography showed the residual AVM had spontaneously disappeared. He was discharged without deficits. Change of cerebral hemodynamics after removal of the larger AVM presumably caused the spontaneous regression of the smaller one. Cerebral angiograms should be carefully examined because cerebral hemodynamics may be altered after removal of an AVM.