Arteriovenous Malformations (AVM)

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

What is an Arteriovenous Malformation?

An arteriovenous malformation, abbreviated as AVM, is an irregular cluster of blood vessels, including arteries and veins, that are abnormally formed. These malformations pose a high risk of bleeding, especially when located in the brain, making them particularly hazardous. Since the brain and its arteries develop simultaneously during embryonic growth, abnormalities in blood vessel formation often coincide with abnormalities in brain tissue. Consequently, AVMs are frequently associated with brain tissue irregularities.

AVMs in the brain can vary in size and location and affect less than one percent of the population. Although they are believed to develop before or shortly after birth, symptoms can manifest at any age.

Causes

The precise causes of arteriovenous malformations remain unclear. Normally, arteries and veins are connected by tiny structures called capillaries, but AVMs occur when arteries link directly to veins without these intermediary vessels.

The pressure within AVMs can cause them to rupture, leading to blood vessel tissue damage and subsequent bleeding into the brain and surrounding tissues. This bleeding diminishes blood flow to the brain.

Symptoms

The symptoms depend on their size and location. Some AVMs may be asymptomatic, while others can cause:

• Seizures: AVMs disrupt brain electrical activity, potentially triggering seizures.
• Headaches: Increased blood flow through the AVM can cause headaches, ranging from mild to severe, sometimes resembling migraines.
• Stroke-like symptoms: AVMs may impede oxygen and nutrient delivery to the brain, resulting in symptoms similar to those of a stroke, such as partial paralysis, weakness, numbness, vision or hearing problems, balance issues, memory loss, or personality changes.

Several diagnostic tests can aid in identifying and assessing AVMs:

• Cerebral angiography: A dye is injected into the bloodstream, and X-rays capture images of the brain to reveal the size and location of AVMs.
• Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA): These techniques produce detailed images of blood vessels, helping to detect AVMs.
• Computed tomography (CT) scan: X-rays create images that can reveal bleeding in the brain.

Treatment

Treatment for arteriovenous malformations depends on their size and location and may include:

• Embolization: Injecting a non-reactive glue to block off the AVM.
• Radiation therapy: Using X-rays to shrink and close off the AVM over time.
• Surgical removal: Excising the AVM, which provides an immediate cure as it does not regenerate.

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.