Arteriovenous malformation of the vein of Galen: a rare cerebral arteriovenous malformation.

A 32-year-old male presented to the emergency department for evaluation of a 12-day history of altered mental status. Workup revealed the presence of an arteriovenous malformation (AVM) of the great vein of Galen, an exceedingly rare and often fatal type of cerebral vascular malformation. Concurrent aneurysmic dilatation of the vein, a frequent finding associated with this type of AVM, resulted in compression of the aqueduct of Sylvius and acute hydrocephalus. A brief review of cerebral AVMs is presented, with specific attention to the pathophysiology, clinical presentation, and emergent treatment of those that involve the vein of Galen.