Arteriovenous Malformation

An arteriovenous malformation (AVM) is an abnormal tangle of blood vessels connecting arteries and veins, which disrupts normal blood flow and oxygen circulation. Arteries are responsible for taking oxygen-rich blood from the heart to the brain. Veins carry the oxygen-depleted blood back to the lungs and heart. When an AVM disrupts this critical process, the surrounding tissues may not get enough oxygen, and the affected arteries and veins can weaken and rupture. If the AVM is in the brain and ruptures, it can cause bleeding in the brain (hemorrhage), stroke or brain damage. An arteriovenous malformation can develop anywhere in your body but occurs most often in the brain or spine. The cause of AVMs is not clear. They're rarely passed down among families. Once diagnosed, a brain AVM can often be treated successfully to prevent or reduce the risk of complications.

Symptoms

Symptoms of AVM vary based on where it's located. Often the first signs and symptoms appear after bleeding occurs, and can include:

• Bleeding
• Progressive loss of neurological function
• Headaches
• Nausea and vomiting
• Seizures
• Loss of consciousness

Other possible signs and symptoms include:

• Weak muscles
• Paralysis in one part of the body
• Loss of coordination (ataxia) that can cause problems with gait
• Problems performing tasks that require planning (apraxia)
• Weakness in the lower extremities
• Back pain
• Dizziness
• Vision problems, including losing part of your field of vision, loss of control of eye movements, or swelling of part of the optic nerve
• Problems with speech or understanding language (aphasia)
• Unusual sensations including numbness, tingling or sudden pain
• Memory loss or dementia
• Hallucinations
• Confusion