Bilateral parietal arteriovenous malformations: report of a case.

A patient with bilateral parietal arteriovenous malformations (AVMs) is reported. The clinical presentation included seizures, coma, and signs of tentorial herniation. After the evacuation of a large left intraparietal hematoma, cerebral angiography identified a small left parietal AVM, which was excised. Mass effect and increased intracranial pressure were present at the time of the initial angiography, and the presence of a right parietal AVM was not appreciated. Postoperative cerebral angiography to document excision of the left parietal AVM then disclosed the small right parietal AVM, which was later excised. The patient has recovered very well. The natural history of AVMs and the occurrence of multiple AVMs are discussed.