Arteriovenous Malformations of the Central Nervous System

(AVM; Arteriovenous Malformations of the Brain; Arteriovenous Malformations of the Spinal Cord)

How to Say It: Ar-teer-ee-o-vee-nus Mal-form-ay-shons


Arteriovenous malformations (AVMs) are abnormal tangles of blood vessels. They can be found anywhere in the body. AVMs of the brain and spinal cord are the most serious.

Arteriovenous Malformation in the Brain

AVM brain blood vessels
Copyright © Nucleus Medical Media, Inc.


The cause is not known.

Risk Factors

Things that may raise the risk are:

  • A family history of AVMs
  • Prior head injury
  • Prior surgery or radiation therapy


Not all people have symptoms. Symptoms may vary in those who do. It depends on the size and location of the AVM. A person may have:

  • Headaches
  • Loss of movement on one side of the body
  • Weakness
  • Sudden, severe back pain
  • Problems with certain movements, such as walking
  • Speaking problems
  • Vision problems
  • Memory loss
  • Confusion or problems thinking
  • Shaking that they cannot control


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

Images may be taken. This can be done with:

AVMs that do not cause symptoms may be found during testing for another health problem.


The goal of treatment is to prevent bleeding and to remove the AVM.

Care depends on if the AVM has ruptured or not. Sometimes, more than 1 method is used. Care may be in a hospital.


Medicines may be given to manage an AVM that has not ruptured. They may also be given to ease:

  • Pain
  • High blood pressure
  • Blood clots
  • Seizures
  • Pressure inside the skull


If the AVM has ruptured, surgery may be delayed for 2 to 6 weeks. The type of surgery depends on the size and site of the AVM. Options are:

  • Microsurgery —An operation to remove the AVM. A special microscope will help the surgeon see the area.
  • Embolization —A tube is inserted through the skin. It is passed through arteries until it reaches the AVM. A substance is passed to the area. It will block off blood flow to the AVM.
  • Radiosurgery —A beam of radiation is focused on the AVM. It destroys the blood vessel walls leading to the AVM. This will block off blood flow to AVM.


There is no way to prevent AVMs. The cause is not known.


American Stroke Association
National Institute of Neurological Disorders and Stroke


Canadian Neurological Sciences Federation
Heart and Stroke Foundation


Arteriovenous malformation information page. National Institute of Neurological Disorders and Stroke website. Available at: Accessed October 1, 2020.
Intracerebral hemorrhage. EBSCO DynaMed website. Available at: Accessed October 1, 2020.
Nussbaum ES. Vascular malformations of the brain. Minn Med. 2013 May;96(5):40-43.
Seizure in adults. EBSCO DynaMed website. Available at: Accessed October 1, 2020.
Spinal cord arteriovenous malformations (AVMs). Merck Manual Professional Version website. Available at:
...(Click grey area to select URL)
Accessed October 1, 2020.
Vascular malformations in the brain. EBSCO DynaMed website. Available at: https://www.dyname.... Accessed October 1, 2020.
What is an arteriovenous malformation (AVM)? American Stroke Association website. Available at:
...(Click grey area to select URL)
Accessed October 1, 2020.
Last reviewed September 2020 by EBSCO Medical Review Board Rimas Lukas, MD
Last Updated: 5/21/2021

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at Our Health Library Support team will respond to your email request within 2 business days.