Moyamoya Disease

Access to the most successful surgical treatment of this rare, life-threatening condition

Moyamoya disease is a very rare disorder that causes the blood vessels at the base of the brain to narrow, slowing blood flow to the brain.

Moyamoya causes reduced blood flow to your brain. When blood flow to the brain is reduced or completely blocked, your risk of having a stroke increases.

Moyamoya disease gets its name 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.

Risk Factors

Moyamoya disease affects both children and adults and people of all ethnicities. It is sometimes seen in children with one of the following conditions:

  • Brain tumor near base of brain
  • Down syndrome
  • Graves disease
  • Neurofibromatosis
  • Sickle cell anemia

Some children develop Moyamoya disease after a viral illness. The disorder may run in families but in most cases, there is no known cause.

Symptoms

In many people with Moyamoya disease, including children, the first sign of the disorder is a stroke or recurrent transient ischemic attacks (TIAs), which are also called mini-strokes. Symptoms can include:

  • Decline in cognitive functioning or learning
  • Paralysis on one side of the body
  • Seizures
  • Severe, persistent headaches
  • Sudden slurred speech

Understanding Moyamoya Disease

Moyamoya causes reduced blood flow to your brain. When blood flow to the brain is reduced or completely blocked, your risk of having a stroke increases.

Moyamoya disease gets its name 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.

Risk Factors

Moyamoya disease affects both children and adults and people of all ethnicities. It is sometimes seen in children with one of the following conditions:

  • Brain tumor near base of brain
  • Down syndrome
  • Graves disease
  • Neurofibromatosis
  • Sickle cell anemia

Some children develop Moyamoya disease after a viral illness. The disorder may run in families but in most cases, there is no known cause.

Symptoms

In many people with Moyamoya disease, including children, the first sign of the disorder is a stroke or recurrent transient ischemic attacks (TIAs), which are also called mini-strokes. Symptoms can include:

  • Decline in cognitive functioning or learning
  • Paralysis on one side of the body
  • Seizures
  • Severe, persistent headaches
  • Sudden slurred speech

IU Health neuroradiologists use 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 neurosurgeons make a treatment plan.

During a cerebral angiogram, a catheter is inserted into the femoral artery and guided up to the carotid artery—the vessel in your neck that leads to your brain. 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.

How is Moyamoya Disease Diagnosed?

IU Health neuroradiologists use 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 neurosurgeons make a treatment plan.

During a cerebral angiogram, a catheter is inserted into the femoral artery and guided up to the carotid artery—the vessel in your neck that leads to your brain. 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 for Moyamoya disease, you have an 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. The IU 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.

Pial Synangiosis Surgery

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 membrane 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. 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.

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.

Treatment

Without treatment for Moyamoya disease, you have an 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. The IU 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.

Pial Synangiosis Surgery

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 membrane 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. 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.

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.

Patient Stories for Moyamoya Disease

Genetics Home Reference

This National Institutes of Health website provides information about Moyamoya disease and its genetic inheritance pattern.

Resources

Genetics Home Reference

This National Institutes of Health website provides information about Moyamoya disease and its genetic inheritance pattern.