When developed normally, arteries carry blood containing oxygen from the heart to the brain, and veins carry blood with less oxygen away from the brain and back to the heart. When a person has an arteriovenous malformation (AVM), the blood vessels in the brain or on its surface are tangled and bypass normal brain tissue, directly diverting blood from the arteries into the veins. Patients with AVM are at risk for hemorrhaging, death, or serious complications.
At Texas Neurosurgery, we can surgically remove the AVM or use other methods to treat this dangerous condition.
Who gets AVM?
AVMs can occur just about anywhere in the body, but are the most common in the brain or spine. The condition is congenital and occurs in less than one percent of the general population. AVMs are more frequent in men than women.
Where and why
It’s not understood why AVMs form. While they are congenital, they are not hereditary. Brain AVMs can occur anywhere within the brain or on its covering.
What are the symptoms of a brain AVM?
Patients with an AVM do not usually experience any symptoms until the AVM ruptures, causing hemorrhaging within the brain. Once this has happened, symptoms may include:
- Weakness and numbness
- Pulsing noise in the head
- Vision loss
- Difficulty speaking
A ruptured AVM is life threatening and requires immediate treatment in order to reduce the risk of death or serious complications.
How we diagnose an AVM
Most brain AVMs are detected with either a computed tomography (CT) brain scan or a MRI brain scan. These tests are excellent at detecting brain AVMs. They also provide information about the location and size of the AVM and whether it may have bled. A cerebral angiogram may also be used.
If an AVM has bled or is in an area easily accessed, surgical removal may be recommended. If the AVM is not too large and is in a difficult-to-reach area, we may use sterotactic radiosurgery. First, a cerebral angiogram is done to localize the AVM. Then focused-beam high-energy sources are concentrated on the brain AVM to produce direct damage to the vessels that will them clot and close off. Interventional neuroradiology/endovascular neurosurgery may be done by placing a catheter inside the blood vessels that supply the AVM and blocking off the abnormal blood vessels with various materials. This stops the blood flowing to the AVM.