Arteriovenous malformation (AVM) is a congenital condition that occurs when there is an abnormal network of blood vessels in the brain. These abnormal vessels can make it harder for areas of the brain to receive sufficient oxygenation and the vessels may eventually rupture. Identifying the problem early can give people with AVM the best chance of avoiding significant brain damage.


Many instances of AVM are not identified until there is a brain bleed, which causes symptoms similar to a ruptured aneurysm. These symptoms can include a severe headache, blurred vision, slurred speech, or loss of consciousness. Some people may experience symptoms well before any blood vessels rupture. There may be a history of seizures or they may have symptoms of an ischemic stroke, such as paralysis, facial drooping, and difficulty speaking. Even seemingly minor symptoms should be evaluated by your doctor. Sudden, severe symptoms always warrant prompt medical care in an emergency setting.

Imaging Tests

Different imaging tests may be used depending on the urgency of the situation. If your symptoms are severe and appear consistent with a stroke or life-threatening neurological condition, a CT scan can be done quickly. The scan may show areas of bleeding in the brain or places where brain tissue has begun to die because of lack of oxygen. When your symptoms are less urgent, doctors may recommend testing to visualize the blood vessels within the brain. A cerebral angiogram requires injection of a contrast dye into a major blood vessel. The contrast allows the radiologist to visualize your blood vessels with radiography. Images are taken in rapid succession so the contrast can be seen moving through your blood vessels almost in real time. The radiologist can see areas where there is a blockage or narrowing of the blood vessels or in the case of AVM, there will be an abnormal network of vessels in the brain.


Once AVM is diagnosed, it is necessary to use surgical approaches to eliminate the abnormal blood vessels. In emergency situations, an open procedure is typically performed to quickly access the area. The abnormal vessels can be clamped and removed, which encourages blood to flow through the appropriate blood vessels. When the situation is less urgent, other techniques can be attempted that are less invasive. Similar to a cerebral angiogram, a large blood vessel can be used to thread a catheter up toward the brain. Once the catheter is in the appropriate location, doctors can inject material to create a clot and block the blood flow in the abnormal vessels.

AVM is often diagnosed once a blood vessel ruptures. Any symptoms that could be consistent with a neurological emergency require prompt evaluation to minimize the chance of permanent damage or life-threatening bleeding. For more information, reach out to companies like Neurosurgical Associates of San Antonio