Arteriovenous Malformations AVM

Arteriovenous Malformation:improperly formed blood vessels. If in brain, seizure, headache, stroke-like symptoms may occur.

Arteriovenous Malformation AVM

Arteriovenous Malformation

What is an Arteriovenous Malformation?

An arteriovenous malformation, or AVM, is a knot of abnormal and poorly formed blood vessels, like arteries and veins. They have a high tendency to bleed, so while AVMs can form in any part of the body, the potential for bleeding makes AVMs that form in the brain potentially very dangerous. The brain and its arteries are formed at the same time during embryological development; therefore, abnormal formations of blood vessels are usually associated with abnormal brain tissues. As a result, AVMs are also associated with abnormalities of the brain tissues.

The size and location of AVMs vary in the brain. AVMS affect less than one percent of the population. Although AVMs are believed to develop before or shortly after birth, their symptoms may appear at any age.

Causes of Arteriovenous Malformations

The causes of arteriovenous malformations are not yet fully known. Arteries are connected to veins by structures called capillaries. AVMs are formed when arteries connect to veins without the presence of capillaries.

AVMs can rupture from pressure, which can damage the tissues of the blood vessels. This results in blood escaping from the vessels and leaking into the brain and surrounding tissues. The flow of blood to the brain is reduced as a result of this bleeding.

Symptoms of Arteriovenous Malformations

The symptoms depend on the size and location of the arteriovenous malformation. An AVM may not exhibit any symptoms in some cases. Possible symptoms include:

  • Seizures: AVMs can affect the electrical activity in the brain. This may result in seizures.
  • Headaches: Headaches may occur due to high flow of blood through the AVM. Migraines or headaches similar to migraine may occur. They might be mild or severe.
  • Stroke-like symptoms: AVMs may deprive the brain of oxygen and essential nutrients, leading to stroke-like symptoms. These may include partial paralysis of one side of body, weakness in one side of body, loss of sensation or numbness, problems with vision, hearing, and balance. Loss of memory and changes in personality might also occur.

The following tests may be used to help your doctor diagnose and determine the best treatment options for arteriovenous malformations:

  • Cerebral Angiography: A dye is injected into the blood, then x-rays of the brain are taken. Cerebral angiography helps to detect the size and location of arteriovenous malformations.
  • Magnetic Resonance Imaging, or MRI, and magnetic resonance angiography, or MRA: These techniques help produce highly detailed images of the blood vessels and can highlight AVMs.
  • Computed Tomography, or CT scan: CT scan uses X-rays to take pictures and highlight the bleeding into the brain and the spaces.

How are Arteriovenous Malformations treated?

The type of treatment is based upon the size and location of the AVM. The following treatment options are available:

  • Embolization: A liquid, non-reactive glue is used to block off the AVM.
  • Radiation therapy: X-rays are used to reduce the size of the AVM and close it off over a set period of time.
  • Surgical removal: The AVM is cut out and removed. This immediately cures an AVM because it will not grow back.

All information provided on this website is for information purposes only. Please see a healthcare professional for medical advice. If you are seeking this information in an emergency situation, please call 911 and seek emergency help.

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COVID-19 Update:
We are still open and treating patients, however, in order to assist in minimizing the spread of the COVID-19 virus and in order to make it safer for you we have made some changes which, we hope, will be temporary.

Appointments made for office visits will be distanced apart in order to avoid crowding the waiting room.

In addition, we are currently working a reduced office schedule of Monday, Wednesday, and Thursday from 8:30 AM to 12 noon. If for some reason, you are only able to come in the afternoon special arrangements can be made.

If you call the office and the answering service answers, you can leave a message with them for a routine follow-up and we will call you back. If you believe your symptoms are more serious, then please ask the answering service to patch the call through to me.

For some types of office visits, we also have telemedicine options that can be downloaded for free onto your iPhone. These include Zoom and FaceTime.

Thank you for your continued support during these times and we look forward to serving you in full capacity towards the end of April.


Donald Mackenzie, M.D, F.R.C.S.C, F.A.C.S.