Arteriovenous malformations: epidemiology, clinical presentation, and diagnostic evaluation.

Brain arteriovenous malformations (AVMs) represent an uncommon disease of the central nervous system characterized by an arteriovenous shunt in which one or multiple arterial pedicles feed into a vascular nidus, creating early drainage into a venous outflow channel. These lesions are considered to be congenital and can come to clinical attention in a variety of ways such as seizure, intracranial hemorrhage, chronic headache or progressive neurological deficit. We focus on the epidemiology, clinical presentation and diagnostic evaluation in this chapter.