Arteriovenous malformations (AVM) of the brain and spinal cord are tangles of abnormal blood vessels. They can form wherever arteries and veins exist. The ones that form in the brain or spinal cord have the most serious symptoms.
Arteriovenous Malformation in the Brain
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The exact cause of arteriovenous malformations is unknown.
Risk factors that increase your chance of getting arteriovenous malformations include:
- Family history—some types of arteriovenous malformations are from genetic defects that can be passed on from one generation to the next.
- History of bleeding—some types of arteriovenous malformations are linked to an increased risk of bleeding. People with unexplained recurrent bleeding may be at higher risk of having arteriovenous malformations.
There are a number of symptoms that you may have if you have an arteriovenous malformation. Symptoms vary from person to person. They also depend on the location of the arteriovenous malformation in your body.
Symptoms may include:
- Headache, especially on one side of the head
- Muscle weakness
- Loss of movement on one side of the body
- Unable to perform movements, but not due to loss of movement
- Loss of coordination, especially when walking
- Sudden, severe back pain
- Difficulty speaking or understanding language
- Loss of senses
- Visual problems
- Memory loss
- Difficulty thinking or mental confusion
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
Images may be taken of your bodily structures. This can be done with:
- Angiography or arteriography
- Computed axial tomography (CT scan or CAT scan)
- Magnetic resonance imaging (MRI)
- Magnetic resonance angiogram (MRA)
You may be referred to a specialist for an exam and treatment. There are a number of specialists who focus on arteriovenous malformation such as neurologists, neurosurgeons, and interventional neuroradiologists.
Gamma Knife radiosurgery has been very successful at treating small to medium-sized AVMs. Obliteration (destruction) rates for AVMs less than 3 cm in diameter are about 80 to 85%.
We treat patients with large AVMS (which usually can’t be operated on) if our team of neurosurgeons and neuroradiologists evaluates a patient's clinical information and images and finds that Gamma Knife radiosurgery and/or embolization possible.
Gamma Knife (with or without embolization) may be the best chance for successful destruction of the AVM, especially when microsurgery may not be possible because of its location and size.
For extremely large AVMs (with volumes of 40 to 50 cc), we use a staged approach. We divide one large AVM into two parts, treating one part in the first session and the other part three to six months later. We make every attempt to minimize the risks and maximize the benefits of radiosurgery. We follow up:
- Every six months with magnetic resonance imaging (MRI)
- After three years, with an angiogram to determine if the AVM has been destroyed.
If the AVM has decreased in volume but still remains, we may repeat radiosurgery.
There is no way to prevent an arteriovenous malformation. To help reduce your chances of hemorrhaging, take the following steps:
- Learn about ways to avoid high blood pressure, such as:
- Avoid heavy lifting.
- Stop smoking.
- Maintain a healthy weight.
- Limit alcohol.
- Eat a healthy diet that is low in sodium.
- Avoid blood thinners, if possible.
- Continue to see your doctor and a neurologist to regularly check the condition of your arteriovenous malformation.