Cerebral arteriovenous malformationAVM - cerebral; Arteriovenous hemangioma; Stroke - AVM; Hemorrhagic stroke - AVM
A cerebral arteriovenous malformation (AVM) is an abnormal connection between the arteries and veins in the brain that usually forms before birth.
The exact cause of cerebral AVM is unknown, however growing evidence suggests a genetic cause. An AVM occurs when arteries in the brain connect directly to nearby veins without having the normal small vessels (capillaries) between them.
AVMs vary in size and location in the brain.
An AVM rupture occurs because of pressure and damage to the blood vessel. This allows blood to leak (hemorrhage) into the brain or surrounding tissues and reduces blood flow to the brain.
Cerebral AVMs are rare. Although the condition is present at birth, symptoms may occur at any age. Ruptures happen most often in people ages 15 to 20. It can also occur later in life. Some people with an AVM also have brain aneurysms.
An aneurysm is a weak area in the wall of a blood vessel that causes the blood vessel to bulge or balloon out. When an aneurysm occurs in a blood ve...Read Article Now Book Mark Article
In about one half of people with AVMs, the first symptoms are those of a stroke caused by bleeding in the brain.
A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack. " If blood flow is cut off for longer th...Read Article Now Book Mark Article
Symptoms of an AVM that is bleeding are:
- Ear noise/buzzing (also called pulsatile tinnitus)
Tinnitus is the medical term for "hearing" noises in your ears. It occurs when there is no outside source of the sounds. Tinnitus is often called "r...Read Article Now Book Mark Article
- Headache in one or more parts of the head, may seem like a migraine
A headache is pain or discomfort in the head, scalp, or neck. Serious causes of headaches are rare. Most people with headaches can feel much better...Read Article Now Book Mark Article
- Problems walking
A seizure is the physical changes in behavior that occurs during an episode of abnormal electrical activity in the brain. The term "seizure" is often...Read Article Now Book Mark Article
Symptoms due to pressure on one area of the brain include:
- Vision problems
There are many types of eye problems and vision disturbances, such as: Halos Blurred vision (the loss of sharpness of vision and the inability to see...Read Article Now Book Mark Article
- Muscle weakness in an area of the body or face
Weakness is reduced strength in one or more muscles.Read Article Now Book Mark Article
- Numbness in an area of the body
Exams and Tests
Your health care provider will perform a physical examination. You'll be asked about your symptoms, with a focus on your nervous system problems. Tests that may be used to diagnose an AVM include:
- Brain angiogram
Cerebral angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the brain.Read Article Now Book Mark Article
- Computed tomography (CT) angiogram
Computed tomography (CT) angiogram
CT angiography (CTA) combines a CT scan with the injection of dye. CT stands for computed tomography. This technique is able to create pictures of ...Read Article Now Book Mark Article
- Head MRI
A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding...Read Article Now Book Mark Article
- Electroencephalogram (EEG)
An electroencephalogram (EEG) is a test to measure the electrical activity of the brain.Read Article Now Book Mark Article
- Head CT scan
Head CT scan
A head computed tomography (CT) scan uses many x-rays to create pictures of the head, including the skull, brain, eye sockets, and sinuses.Read Article Now Book Mark Article
- Magnetic resonance angiography (MRA)
Magnetic resonance angiography (MRA) is an MRI exam of the blood vessels. Unlike traditional angiography that involves placing a tube (catheter) int...Read Article Now Book Mark Article
Determining the best treatment for an AVM that is found on an imaging test, but is not causing any symptoms, can be difficult. Your provider will discuss with you:
- The risk that your AVM will break open (rupture). If this happens, there may be permanent brain damage.
- The risk for any brain damage if you have one of the surgeries listed below.
Your provider may discuss different factors that may increase your risk for bleeding, including:
- Current or planned pregnancies
- What the AVM looks like on imaging tests
- Size of the AVM
- Your age
- Your symptoms
A bleeding AVM is a medical emergency. The goal of treatment is to prevent further complications by controlling the bleeding and seizures and, if possible, removing the AVM.
Three surgical treatments are available. Some treatments are used together.
Open brain surgery removes the abnormal connection. The surgery is done through an opening made in the skull.
Embolization (endovascular treatment):
Endovascular embolization is a procedure to treat abnormal blood vessels in the brain and other parts of the body. It is an alternative to open surg...Read Article Now Book Mark Article
- A catheter is guided through a small cut in your groin. It enters an artery and then into the small blood vessels in your brain where the aneurysm is located.
- A glue-like substance is injected into the abnormal vessels. This stops the blood flow in the AVM and reduces the risk of bleeding. This may be the first choice for some kinds of AVMs, or if surgery can't be done.
Stereotactic radiosurgery (SRS) is a form of radiation therapy that focuses high-power energy on a small area of the body. Despite its name, radiosu...Read Article Now Book Mark Article
- Radiation is aimed directly on the area of the AVM. This causes scarring and shrinkage of the AVM and reduces the risk of bleeding.
- It is particularly useful for small AVMs deep in the brain that are difficult to remove by surgery.
Medicines to stop seizures are prescribed if needed.
Some people, whose first symptom is excessive brain bleeding, will die. Others may have permanent seizures and brain and nervous system problems. AVMs that do not cause symptoms by the time people reach their late 40s or early 50s are more likely to remain stable, and in rare cases, cause symptoms.
Complications may include:
- Brain damage
- Intracerebral hemorrhage
- Language difficulties
- Numbness of any part of the face or body
Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...Read Article Now Book Mark Article
- Persistent headache
- Subarachnoid hemorrhage
Subarachnoid hemorrhage is bleeding in the area between the brain and the thin tissues that cover the brain. This area is called the subarachnoid sp...Read Article Now Book Mark Article
- Vision changes
- Water on the brain (hydrocephalus)
Hydrocephalus is a buildup of fluid inside the skull that leads to brain swelling. Hydrocephalus means "water on the brain. "Read Article Now Book Mark Article
- Weakness in part of the body
Possible complications of open brain surgery include:
- Brain swelling
When to Contact a Medical Professional
Go to the emergency room or call 911 or the local emergency number if you have:
- Numbness in parts of the body
- Severe headache
- Other symptoms of a ruptured AVM
Also seek medical attention right away if you have a first-time seizure, because AVM may be the cause of seizures.
Nguyen TN, Jovin TG, Nogueira RG, Zaidat OO, eds. Principles of neuroendovascular therapy. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 54.
Patterson JT. Neurosurgery. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 21st ed. St Louis, MO: Elsevier; 2022:chap 68.
Samaniego EA, Roa JA, Ortega-Gutierrez S, Derdeyn CP. Arteriovenous malformations and other vascular anomalies. In: Grotta JC, Albers GW, Broderick JP, et al, eds. Stroke: Pathophysiology, Diagnosis, and Management. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 30.
Arteries of the brain - illustration
The internal carotid arteries and the vertebral arteries supply blood to the brain.
Arteries of the brain
Review Date: 11/2/2022
Reviewed By: Evelyn O. Berman, MD, Assistant Professor of Neurology and Pediatrics at University of Rochester, Rochester, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.