What Is an Arteriovenous Malformation?

An arteriovenous malformation (AVM) is an abnormal connection between arteries and veins. Normally, blood flows through tiny capillaries before returning to the veins. With an AVM, the blood vessels bypass this normal pathway and form a tangled network.

AVMs can develop anywhere in the body, but they are most often found in the brain or spinal cord. Some people never notice symptoms, while others may experience neurological problems or bleeding.

Symptoms

Symptoms can vary depending on where the AVM is located and whether it affects nearby tissues or blood flow.

Common symptoms may include:

• Headaches
• Seizures
• Dizziness
• Weakness in the arms or legs
• Numbness or tingling
• Vision changes
• Difficulty speaking
• Balance or movement problems
• Back pain
• Loss of consciousness

In some cases, an AVM may bleed suddenly, causing stroke-like symptoms that require emergency medical care.

How Is It Diagnosed?

Doctors begin with a physical exam and a review of symptoms and medical history. If an AVM is suspected, imaging tests help providers look at blood vessels and blood flow in detail.

Tests may include:

• MRI scans
• CT scans
• Angiography
• Magnetic resonance angiography (MRA)
• CT angiography (CTA)

These tests help determine the AVM’s size, location, and risk of bleeding.

How Is It Treated?

Treatment depends on the AVM’s location, symptoms, and overall risk. Some AVMs that are small and not causing problems may only need monitoring over time.

Treatment options may include:

• Medications to manage headaches or seizures
• Embolization to block abnormal blood vessels
• Surgery to remove the AVM
• Focused radiation therapy to shrink or close the abnormal vessels

Recovery varies from person to person. Factors such as bleeding, the AVM’s size, and treatment type can affect healing and long-term outcomes.