A brain arteriovenous malformation, also known as a brain AVM, is a congenital condition that involves an abnormal connection between arteries and veins within the brain, causing them to appear tangled and dilated, putting patients at risk for hemorrhaging and other serious complications. AVMs may prevent oxygenated blood from completely circulating throughout the brain, causing symptoms such as headaches and vision problems. AVMs are present at birth and may occur nearly anywhere in the body, but are most common within the brain or spine. The exact cause of this condition is unknown, but it is believed to develop in utero, during fetal development. Brain arteriovenous malformations are more common in males than females and some evidence suggests they may run in families.

Patients with a brain AVM usually do not experience any symptoms until an artery ruptures and causes bleeding or a hemorrhage within the brain. At this time, symptoms may include:

• Seizures
• Headache
• Weakness and numbness
• Pulsing noise in the head
• Vision loss
• Difficulty speaking
• Unsteadiness

A ruptured artery caused by a brain AVM is considered a life-threatening condition and requires immediate treatment in order to reduce the risk of serious complications.

A brain AVM is diagnosed through a medical examination performed by a skilled neurologist. In addition, the following imaging tests may also be performed:

• Cerebral angiography
• CT scan
• MRI scan

These tests provide information about the exact location of the malformation, and allow the doctor to view the characteristics of the arteries and the veins, which is important for determining treatment.

Treatment for an AVM may include several different options depending on the size and location of the affected blood vessels. Medication may be prescribed to treat symptoms such as headaches or seizures. Several procedures may also be performed to treat a brain arteriovenous malformation and may include:

• Surgical removal or resection
• Endovascular embolization
• Stereotactic radiosurgery

In some cases, immediate treatment may not be necessary and the doctor may choose to monitor the patient’s condition before deciding on a specific treatment. The outlook for successful treatment is highest in patients who experience early symptoms from an AVM prior to hemorrhaging.

• MedlinePlus
• National Institutes of Health
• Centers for Disease Control and Prevention
• Eunice Kennedy Shriver National Institute of Child Health and Human Development
• U.S. Department of Health & Human Services
• U.S. National Library of Medicine
• WebMD