Moyamoya Disease

The Indiana University Health Neuroscience Center is one of only a few medical centers in the nation with the specialized neurosurgical expertise to provide advanced treatment for Moyamoya disease. Moyamoya disease is a very rare disorder that affects the blood vessels in the brain. The disease causes the blood vessels at the base of the brain to narrow, slowing blood flow to the brain. When blood flow to the brain is reduced or completely blocked, the risk of having a stroke is increased.

Moyamoya disease can affect both children and adults and people of all ethnicities. It is sometimes seen in children with Down syndrome, neurofibromatosis, sickle cell anemia, Graves' disease and in children who have brain tumors near the base of the brain. Some children develop Moyamoya disease after a viral illness. The disorder may run in families; however, in most cases of Moyamoya, there is no known cause.

The disease’s name derives from the Japanese word for “puff of smoke.” When the brain cannot get enough blood, tiny blood vessels form at the base of the brain to make up for the lack of blood supply. When seen on a cerebral angiogram—an X-ray that examines how blood flows through the brain—the tangle of new blood vessels can look like a small, dark cloud or puff of smoke.

In many people with Moyamoya disease, including children, the first sign of the disorder is stroke or recurrent transient ischemic attacks (TIAs), which are also called mini-strokes. Parents may notice muscle weakness or paralysis on one side of the child’s body or sudden slurred speech. Other symptoms can include:

  • Decline in cognitive functioning or learning
  • Seizures
  • Severe, persistent headaches

At the IU Health Neuroscience Center, highly specialized neuroradiologists use sophisticated magnetic resonance imaging (MRI) and computed tomography (CT) imaging to examine the brain’s blood vessels. These imaging studies help doctors locate and evaluate the blockage in the carotid arteries at the base of the brain. The studies can also identify signs of past stroke or mini-strokes.

Once the diagnosis of Moyamoya disease is confirmed, neuroradiologists perform a cerebral angiogram. This detailed study of the arteries helps IU Health Neuroscience Center neurosurgeons make a treatment plan. During a cerebral angiogram, a catheter is inserted into the femoral artery and guided up to the carotid artery. A dye is then injected into the artery. X-ray images highlight how the dye moves through the brain’s arteries, helping doctors pinpoint the area and extent of blockage. 

Without treatment, people with Moyamoya disease have increased risk of stroke, severe disability and death. Medicine can help lower the risk for blood clots, but surgery is the only cure for Moyamoya disease.

Pial Synangiosis Surgery

At the IU Health Neuroscience Center, a highly skilled pediatric neurosurgeon performs pial synangiosis surgery for Moyamoya disease. In this delicate procedure, a small incision is made in the scalp to expose a healthy blood vessel. Then, with the aid of a high-powered operating microscope, each of the brain’s coverings is opened to expose the pial surface of the brain. Using tiny sutures, the scalp artery is secured directly to the pial surface of the brain. Over time, the healthy blood vessel will stimulate growth of new blood vessels, replacing the lost blood supply from the blocked artery. This process is known as angiogenesis.

While there are other surgical options for Moyamoya disease, pial synangiosis is the most successful treatment option for children. This procedure was introduced at another healthcare facility where Jodi Smith, PhD, MD, a neurosurgeon practicing at IU Health and Riley Hospital for Children at Indiana University Health, completed her fellowship training in pediatric neurosurgery. She is one of only a few neurosurgeons in the United States who received training from the surgeon who pioneered this procedure.

Because children with Moyamoya disease have a heightened risk for stroke during surgery, it is especially important that surgery include anesthesiologists who have treatment experience with this disorder. Riley Hospital for Children at IU Health has a dedicated Moyamoya anesthesia protocol, and all of our neurosurgery anesthesiologists are experienced in managing Moyamoya disease to reduce stroke risk during surgery.

After surgery, most patients remain in the hospital for about three days and typically return to regular activities in about four weeks. Children can return to school one to two weeks after surgery.