Arteriovenous Malformation (AVM)
An arteriovenous malformation (AVM) is an abnormality of the blood vessels that may be present in the brain or spine and is believed to develop at the time of embryonic development. The malformation results in shunting of blood from arteries to veins, bypassing capillary blood vessels that serve normal brain tissue. The condition is rare and is thought to be present in about 0.1% to 0.2% of the population. The blood vessel abnormalities may not cause any significant neurologic problems and be discovered incidentally, or they may cause a wide variety of symptoms depending on the location. An AVM may be identified after headaches, a seizure, or rupture that causes bleeding. The workup for a patient with a suspected AVM often involves imaging studies such as CT or MRI of the brain, as well as catheter cerebral angiography to comprehensively define the abnormality. Various management strategies are then considered including observation, endovascular embolization, surgical resection, and gamma knife radiation.