What is an Arteriovenous Malformation (AVM)?

Arteriovenous malformations (AVM) are abnormal connections between arteries and veins that usually form before birth. Cerebral Arteriovenous Malformations occur between arteries and veins in the brain. Small blood vessels (capillaries) normally connect arteries and veins but are absent with AVM, resulting in a tangle of arteries and veins, which disrupt the normal blood flow in the brain. Without the benefit of capillaries serving as connectors to diffuse the buildup of pressure between the arteries and veins, the abnormal structure is susceptible to leaks, ruptures (brain hemorrhage) and the formation of aneurysms

Arteriovenous malformations vary in size and location in the brain and account for two percent of all strokes. The overall risk of rupture in a patient’s lifetime is 105 minus your age. So, if you are 35 years old, your lifetime risk of rupture would be 70 percent.

Risk Factors

Arteriovenous Malformations are primarily genetic, although they may progress faster with a history of smoking and hypertension.

Symptoms of a rupture — brain hemorrhage may include:

• Severe headache
• Nausea and vomiting
• Neck pain
• Vision problems
• Seizures
• Collapse and/or Ioss of consciousness
• Instant death

Symptoms or warning signs of an unruptured AVM:

• Seizures
• Temporary neurological problems such as weakness in the arms and legs, facial drooping
• Temporary loss of speech and cognitive function
• Facial pain and vision problems due to pressure on nerves from the abnormal vessels
• Persistent headache, nausea and vomiting due to increased pressure on the brain

Treatment Options

There are currently three treatment options for individuals diagnosed with AVM:

1. Traditional open surgery to remove lesions close to the surface of the brain (May be used in conjunction with embolization)
2. Neuroendovascular surgery (embolization) using Onyx® (a liquid, putty-like substance used to seal off aneurysms)
3. Radiation (primarily used with fine “lacelike” lesions)
   (May be used in combination with embolization and surgery)