Signs and Symptoms

Although people are generally born with arteriovenous malformations (AVMs), they may not experience symptoms for many years, anywhere between age 10 and 40.

However, symptoms of AVM can occur at any age, as is the case for one of the most severe forms of the disease, called a vein of Galen malformation. This condition may cause symptoms at birth or very soon thereafter. Symptoms may include swelling of the brain, seizures, failure to thrive, congestive heart failure and swollen veins.

Each person may experience symptoms differently, depending mostly on the location of the AVM. However, some of the most common symptoms may include:

• Headache, varying in severity, duration and intensity
• Stroke
• Seizures, which may be partial or total and may cause a loss of movement control and consciousness, as well as convulsions
• Muscle weakness or paralysis in one part of the body
• Loss of coordination, known as ataxia
• Dizziness
• Visual disturbances, such as partial loss of eye sight or lack of eye moment control
• Abnormal sensations, such as numbness, tingling or spontaneous pain

Diagnosis

The following tests may be used to determine if your child has an arteriovenous malformation (AVM), as well as help identify its size, location and blood-flow pattern.

• Computed Tomography (CT) -- A CT scan is a method of body imaging in which a thin X-ray beam rotates around the patient. It can be used to detect the presence of blood in the brain.

• Magnetic Resonance Imaging (MRI) -- An MRI scan can detect if there is blood in the brain. It is a non-invasive procedure that uses powerful magnets and radio waves to construct pictures of the body.

• Angiogram -- This is an important test in the diagnosis of AVM and involves a special X-ray exam that enables a radiologist, a doctor who specializes in understanding and interpreting X-rays, to study a person's blood vessels. Your child's doctor will insert a small tube, called a catheter, into the blood vessel and then inject a special dye that makes the vessels visible on the X-rays. This will allow the doctor to observe how the blood travels through the blood vessels of the brain. The procedure takes about one hour.

Treatment

At UCSF Children's Hospital, a team of experts specializing in malformations that affect blood vessels in the brain works together with you and your family to develop the best possible treatment plan for your child. This team includes a neurologist, neurosurgeon, interventional neuroradiologist and radiation oncologist.

Because arteriovenous malformations (AVMs) are one of the leading causes of debilitating hemorrhagic strokes in young people, the goal of treatment is to reduce the risk of stroke. Fortunately, today there are many safe and highly effective therapies available to successfully treat AVMs. These include surgery, radiation therapy, embolization and radiosurgery using a machine called a Gamma Knife.

• Surgery -- In many cases, surgery may be recommended to completely remove the AVM. In addition to conventional brain surgery, advanced, minimally invasive surgical techniques are available to successfully treat AVMs.

  For instance, the Gamma Knife, an advanced radiosurgery treatment for abnormal blood vessel formations, is often recommended for children with complex, deep seated or brain stem AVMs. Despite its name, it isn't a knife at all. It delivers a single, very finely focused, high dose of radiation precisely to its target, while causing little or no damage to surrounding tissue. The Gamma Knife may be used in combination with other treatments, such as surgery, or by itself as the primary therapy.

• Embolization -- Embolization may also be part of your child's treatment plan. This technique aims to reduce blood flow to the AVM by obstructing surrounding blood vessels. During this procedure, the AVM is filled with specially designed coils, glues or spheres, which plug its vessels. As a result, blood flow is decreased, making the AVM more manageable for future procedures such as surgery.