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What are arteriovenous malformations? — Arteriovenous malformations, or "AVMs," are clumps of abnormal blood vessels. People can have AVMs in different places in their body. This article is about AVMs in the brain.
AVMs in the brain are rare and usually form before a person is born. Many times they do not cause any symptoms, but in some people, they do cause serious symptoms or problems. These can happen if an AVM pushes on the brain or keeps part of the brain from getting enough oxygen. An AVM can also sometimes tear open and bleed into the brain. This happens because the blood vessels in an AVM are not as strong as normal blood vessels. A severe bleed in the brain can cause brain injury and death.
What are the symptoms of an AVM? — Many AVMs do not cause any symptoms. People often find out they have an AVM when their doctor does a test for another reason.
When AVMs do cause symptoms, they can cause:
●Seizures – Seizures are waves of abnormal electrical activity in the brain. They can make you pass out, or move or behave strangely.
●Symptoms of a stroke – A stroke is when a part of the brain is damaged because of a problem with blood flow. A stroke can cause:
•A person's face to look uneven or droop to 1 side
•Weakness or numbness in 1 or both arms – For example, 1 arm might drift down if a person tries to hold both arms out.
•Trouble speaking, or speech that sounds strange
•Sudden, severe headache
●Headaches – Sometimes an AVM is found when a person with headaches gets an imaging test to try to find the cause. (Imaging tests, like MRI and CT scan, take pictures of the brain.) It is not always clear whether the AVM is the cause of the headaches, since headaches happen in many people who do not have an AVM.
Should I call the doctor or nurse? — Yes. If you have a seizure or severe headache, call your doctor or nurse right away.
If you have symptoms of a stroke, call for an ambulance (in the US and Canada, dial 9-1-1).
Is there a test for an AVM? — Yes. Doctors can do different tests to check for an AVM. Tests can include:
●A CT or MRI scan of the brain – These are imaging tests that create pictures of the inside of the brain.
●Cerebral angiography – This test shows how blood flows through the blood vessels in the brain. For this test, the doctor will put a thin tube into a large blood vessel in your body, usually one in your leg. Then the doctor will move the tube up into your neck. When the tube is in place, they will inject a dye into the tube and take X-rays. The dye will show up on the X-rays.
How is an AVM treated? — Treatment depends on different factors, including:
●Whether your AVM is bleeding or not
●How big your AVM is and where it is in your brain
●Your symptoms
If your AVM is not bleeding or causing symptoms, your doctor will talk with you about whether it needs to be treated. Not all AVMs need to be treated, especially if they are not bleeding or causing symptoms.
There are benefits and downsides to treating AVMs that are not bleeding or causing symptoms. The main benefit is that treatment can prevent a future bleed in the brain. The main downside is that the treatments can cause problems of their own. For example, surgery can cause a seizure, stroke, or brain swelling or bleeding.
If your AVM is causing seizures, your doctor will treat your seizures with anti-seizure medicines. These medicines can help prevent you from having more seizures.
AVMs that cause bleeding usually need treatment. The different treatments for an AVM include:
●Surgery to remove the AVM
●Radiosurgery – This is not surgery. It involves getting radiation (high doses of X-rays) in the area of the AVM. Over time, the radiation makes the AVM less likely to bleed. This treatment usually takes a few years to work.
●Embolization – This is a procedure done during cerebral angiography. The doctor puts a material into the blood vessel that brings blood to the AVM. The material blocks off the blood vessel. Sometimes this procedure works on its own. Other times, doctors do surgery or radiosurgery after it.
What if I want to get pregnant? — If you have an AVM and want to get pregnant, talk with your doctor. They might recommend treating your AVM before you try to get pregnant.
Patient education: Hemorrhagic stroke (The Basics)
Patient education: Stroke (The Basics)
Patient education: Seizures (The Basics)
Patient education: Headaches in adults (The Basics)
Patient education: Hemorrhagic stroke treatment (Beyond the Basics)
Patient education: Stroke symptoms and diagnosis (Beyond the Basics)
Patient education: Seizures in adults (Beyond the Basics)
Patient education: Seizures in children (Beyond the Basics)
Patient education: Headache causes and diagnosis in adults (Beyond the Basics)
