Arteriovenous Malformation

Arteriovenous [ar-TEER-ee-oh-VEE-nus] malformation [mal-for-MAY-shun], or AVM, is a condition that can affect the blood vessels in your child’s body, causing them to grow the wrong way or get tangled up with each other. People with an AVM might not have capillaries [KAP-uh-ler-eez] in certain parts of their body, and they might have veins and arteries that get tangled up. When this happens, old blood and new blood can get mixed up, and certain parts of the body might not get enough blood. This can cause tissue and nerve damage.

AVMs can happen anywhere in the body, but they are most common in the spinal cord and the brain. Serious AVMs in these areas can cause many issues including seizures, headaches, and other neurological problems.

Some conditions related to AVMs include:

• Aneurysm [ANN-yer-IZ-uhm]. An aneurysm is a weakness in the wall of a blood vessel. These blood vessels can burst, causing a hemorrhage.
• Meningioma [men-in-jee-OH-muh]. This is a benign (non-cancerous), slow-growing tumor in the meninges, the layers of tissue surrounding the brain and spinal cord.
• Acoustic [uh-KOO-stik] neuroma [noo-ROH-muh]. This is a benign tumor that can grow in the nerve leading from the inner ear to the brain.

AVMs can cause many different symptoms, which can vary greatly from person to person. Symptoms can also depend on the exact part of your child’s body that has an AVM. For instance, AVMs in the spine can cause problems with muscles, while brain AVMs can cause neurological problems. Common symptoms are seizures and headaches:

• Seizure. AVMs can cause seizures, which can be focal (only involving a small part of the brain) or general (affecting the entire brain). If your child has a seizure due to an AVM, they might convulse (shake or tense their muscles), lose control over their movement, or pass out.
• Headaches. AVMs can cause many different kinds of headaches, and some can even be as bad as migraines. If your child has headaches that are most often on one side of the head, this can be a sign of an AVM at that location.

AVMs in the brain and spine can cause neurological symptoms, since these parts of the body are sensitive to changes in blood flow or oxygen levels. Some of these symptoms include:

• Muscle Problems. AVMs in the spinal cord can cause weakness or paralysis in one part of the body.
• Ataxia [uh-TAK-see-uh]. This is a loss of coordination that might make your child walk in a strange way.
• Apraxia [uh-PRAK-see-uh]. Problems completing tasks that need planning can be a sign of neurological issues.
• Back pain or weakness. This can be a sign of an AVM in your child’s spinal cord.
• Visual problems. These can include loss of vision, not being able to control the eyes, or swelling in the optic nerve.
• Aphasia [uh-FAY-zhuh]. An AVM might make it hard for your child to talk or understand speech.
• Numbness, tingling, or pain.
• Memory deficits.
• Confusion, hallucinations, or dementia.

The most serious symptom of an AVM is hemorrhage, which is bleeding inside the body. A hemorrhage can happen when AVMs burst or the walls of the blood vessels get too week to hold the blood in. A hemorrhage in the brain or spine can cause serious neurological damage and even death.

An AVM is a serious medical problem, and your child should see a doctor right away if they have some or all of the symptoms listed above. Even if your child doesn’t have an AVM, their doctor can do tests to diagnose or rule out other conditions, like meningioma, that can cause many of the same symptoms.

Your doctor might recommend that your child see a cardiologist, a doctor who specializes in diagnosing and treating problems with the heart and cardiovascular system, or a neurologist, a doctor who specializes in treating the brain.

Doctors and scientists aren’t sure what causes AVMs, but they do know that most of them are congenital, meaning that they are present in a person from the time they are born. Scientists think some AVMs might be inherited, but there are also other inherited conditions that make AVMs more likely. It is hard to study the causes of this disease because many people with AVMs don’t know they have them.

If your doctor thinks your child might have an AVM, they will do a physical exam and order tests to take a look at your child’s blood vessels in the brain, spine, or other parts of the body.

During the physical exam, the doctor will ask you and your child questions about their symptoms, how long the symptoms have lasted, and whether they are getting worse. AVMs can cause bruit, a whooshing sound that is caused by blood passing too fast through damaged blood vessels. Your doctor might listen to your child’s blood vessels to see if they can hear this bruit.

Many tests are available to take pictures and videos of your child’s blood vessels to look for AVMs and related problems. These can include:

• X-rays.
• CT scans.
• MRIs.
• MRAs.
• Transcranial Doppler ultrasound.

If your child is diagnosed with an AVM, their doctor might recommend several treatments depending on where the AVM is in their body, how large it is, and how serious your child’s symptoms are.

Medicine can be prescribed to help with symptoms like headaches, back pain, and seizures. However, these medicines don’t get rid of the AVM and the symptoms will probably come back if your child stops taking the medicine.

The best and most common treatment for AVM is surgery or radiation therapy.

• Surgery. In AVM surgery, a surgeon enters the brain or spinal cord and removes the center part of the AVM. Usually, this can be done without causing too much damage to the surrounding nerves and blood vessels in the spine or brain. If your child’s AVM is deep inside of their brain, surgery might not be possible because it could cause damage to other parts of the brain.
• Endovascular [en-DOH-vask-YOU-luhr] embolization [em-buh-liz-AY-shun]. In this procedure, the surgeon puts a catheter [KATH-ih-tur] (a very small tube) through the arteries until the tip reaches the AVM. The surgeon can inject a substance through the catheter that will create a blood clot in the AVM. This procedure is not permanent but can make surgery or radiosurgery safer by reducing blood flow through the AVM.
• Radiosurgery. In this treatment, a beam of high-energy radiation is aimed at the AVM. The beam damages the walls of the blood vessels in the AVM, which causes the AVM to go away over time.

Embolization and radiosurgery might not get rid of the AVM all the way, but they can help shrink the AVM or make it easier for your surgeon to surgically remove it. It might take several different procedures done over a few weeks or months to get rid of the AVM completely.

Because doctors aren’t sure what causes AVMs, there is often no way to prevent them. You should keep track of your child’s health and take them to a doctor right away if they have any neurological symptoms, including headaches or seizures. Early detection can help prevent the most serious problems caused by AVMs, and can give your child’s doctor and medical team more time to treat this disorder.

American Stroke Association

Arteriovenous malformations, or AVMs, are a tangled mass of blood vessels in your child’s body, most commonly found in the brain and spine. They can cause neurological symptoms and even a potentially fatal brain bleed (hemorrhage). AVMs can be treated with surgery, embolization, or radiosurgery.