Arteriovenous Malformations

(AVM; Arteriovenous Malformations of the Brain; Arteriovenous Malformations of the Spine; AMB)

Pronounced: Ar-teer-ee-o-vee-nus Mal-form-ay-shons



Arteriovenous malformations (AVM) of the brain and spinal cord are tangles of abnormal blood vessels. They can form wherever arteries and veins exist. The ones that form in the brain or spinal cord have the most serious symptoms.

Arteriovenous Malformation in the Brain

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The exact cause of arteriovenous malformations is unknown.

Risk Factors

Risk Factors

Risk factors that increase your chance of getting arteriovenous malformations include:

  • Family history—some types of arteriovenous malformations are from genetic defects that can be passed on from one generation to the next.
  • History of bleeding—some types of arteriovenous malformations are linked to an increased risk of bleeding. People with unexplained recurrent bleeding may be at higher risk of having arteriovenous malformations.
  • Smoking



There are a number of symptoms that you may have if you have an arteriovenous malformation. Symptoms vary from person to person. They also depend on the location of the arteriovenous malformation in your body.

Symptoms may include:

  • Seizures
  • Headache, especially on one side of the head
  • Muscle weakness
  • Loss of movement on one side of the body
  • Lightheadedness
  • Unable to perform movements, but not due to loss of movement
  • Loss of coordination, especially when walking
  • Sudden, severe back pain
  • Difficulty speaking or understanding language
  • Loss of senses
  • Visual problems
  • Memory loss
  • Difficulty thinking or mental confusion
  • Hallucinations



You will be asked about your symptoms and medical history. A physical exam will be done.

Images may be taken of your bodily structures. This can be done with:

You may be referred to a specialist for an exam and treatment. There are a number of specialists who focus on arteriovenous malformation such as neurologists, neurosurgeons, and interventional neuroradiologists.



The goal of treatment is to prevent hemorrhaging/bleeding. Hemorrhaging can lead to strokes, which occur due to lack of blood flow or increased pressure.

Your doctor will need to determine if your arteriovenous malformation has bled, if it is not too large, and if it is in an area that can be easily reached and treated.

Talk with your doctor about the best treatment plan for you. Treatment options include the following:


Medication may be taken to ease the symptoms you may be having, such as headache, back pain, and seizures. This does not remove the arteriovenous malformation.


You must work with your doctor to decide whether you’d like to have surgery to treat your arteriovenous malformation. Leaving an arteriovenous malformation untreated may lead to serious complications. However, there is always a risk of nervous system damage with surgery.

There are 3 different types of surgery available. Choosing a surgery type will depend on the size and location of the arteriovenous malformation. The types of surgery include:

Conventional Surgery

This standard surgery involves operating on the area of the brain or spinal cord where the arteriovenous malformation is located. This procedure is the most thorough treatment for arteriovenous malformations.

Endovascular Embolization

Endovascular embolization is often used for arteriovenous malformations that are located deeper within the brain. Regular surgery could damage the surrounding tissue in the brain or spinal cord.

A catheter will be guided through your arteries until it reaches the arteriovenous malformation. Then, a substance will be inserted to plug the fistula. This procedure does not destroy the arteriovenous malformation. It reduces the blood flow to the arteriovenous malformation and makes surgery safer.


This procedure uses a beam of powerful radiation. The beam is focused directly on the arteriovenous malformation. The radiation damages the walls of the blood vessels that lead to the arteriovenous malformation. This procedure does not always completely destroy the arteriovenous malformation, especially if it is large.

Sometimes, arteriovenous malformations are best left alone based on their size and location. It is best to speak with your doctor about your decision.



There is no way to prevent an arteriovenous malformation. To help reduce your chances of hemorrhaging, take the following steps:

  • Learn about ways to avoid high blood pressure, such as:

    • Avoid heavy lifting.
    • Stop smoking.
    • Maintain a healthy weight.
    • Limit alcohol.
    • Eat a healthy diet that is low in sodium.
  • Avoid blood thinners, if possible.
  • Continue to see your doctor and a neurologist to regularly check the condition of your arteriovenous malformation.


American Stroke Association

National Institute of Neurological Disorders and Stroke


HealthLink BC

The Toronto Brain Vascular Malformation Study Group


Arteriovenous malformation information page. National Institute of Neurological Disorders and Stroke website. Available at:
Updated February 23, 2015. Accessed June 29, 2015.

Choi JH, Mohr JP. Brain arteriovenous malformations in adults. Lancet Neurology. 2005; 4(5):299-308.

Geibprasert, et al. Radiologic assessment of brain arteriovenous malformations: what clinicians need to know. Radiographics. 2010;30(2):483-501.

Ogilvy CS, Stieg PE, et al. Recommendations for the management of intracranial arteriovenous malformation: a statement for healthcare professionals from a special writing group of the Stoke Council, American Stroke Association. Stroke. 2001;32:1458.

Van Beijnum J, et al. Treatment of brain arteriovenous malformations: a systematic review and metanalysis. JAMA. 2011;306(18):2011-2019.

What is an arteriovenous malformation (AVM)? American Stroke Association website. Available at:
Updated June 20, 2014.

Last reviewed June 2015 by Rimas Lukas, MD; Michael Woods, MD
Last Updated: 5/11/2013

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