Arteriovenous Malformations

An Arteriovenous Malformation (AVM) is a congenital (present at birth) defect which consists of a tangle of abnormal arteries and veins with no capillaries (small connector vessels) in between. The blood pressure in the veins is higher than normal and may result in a rupture of the vein and bleeding into the brain.

Cause(s)
An AVM is an abnormal development of blood vessels inside or on the surface of the brain before birth. The exact cause is unknown.

Signs & Symptoms
The signs of an AVM are migraine-like headaches, seizures, bruit (an abnormal swishing or ringing sound), and/or a hemorrhage (small stroke). The headache can be accompanied nausea, vomiting, sensitivity to light (photosensitivity), a stiff neck, double vision, difficulty speaking, difficulty swallowing, numbness or tingling of the face, arm or leg or weakness of the face arm or leg.