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Moyamoya disease is rare, affecting one in 100,000 people. Though few places offer care for moyamoya, Barnes-Jewish Hospital is a recognized moyamoya center, treating the majority of patients with moyamoya in the St. Louis region. We see 15 to 25 new patients with moyamoya and perform up to 15 surgeries each year.

Our center has a prominent role in understanding moyamoya in North American patients. This disease is very unique to the patient and requires treatment from a variety of specialists. Since not all moyamoya patients need surgery, management is an important part of your treatment. Both medical and surgical treatment options are available at Barnes-Jewish, where you can find comprehensive care from a team of experts.

Request a call to schedule an appointment with a Washington University neurosurgeon at Barnes-Jewish Hospital. 

What is Moyamoya?

Moyamoya disease a progressive disorder in which the large arteries in the skull (vessels that carry blood to the brain) narrow and often completely close off. Smaller vessels (“branches”) enlarge to bypass the blockage. These vessels can be spotted on an angiogram. 

This disease is more common in Asian countries, especially among children. Moyamoya presents differently in Northern American patients. Barnes-Jewish has great understanding in these differences and was the organizing center for an NIH-funded natural history study on moyamoya patients from North America. 

Moyamoya Symptoms & Causes

Symptoms of moyamoya may include:

Moyamoya affects North American patients in different ways, depending on your age. In children ages 5 to 15, which is a peak of when moyamoya is discovered, a mini-stroke is usually the first sign. Stroke symptoms include sudden weakness or numbness, speech difficulty, dizziness, loss of vision and headache. Stroke and TIA are rare for children, so they are a large indicator of an underlying issue like a heart problem, moyamoya or a different cerebral problem. Our pediatric centers have technologies that help our experts track neurovascular disease that can develop into moyamoya and aneurysms. 

Another peak time for moyamoya diagnosis is ages 20 to 40. Stroke and TIA are often the first sign of moyamoya in adults, as well. Moyamoya affects women much more commonly than men. 

Since moyamoya is so uncommon, it is difficult to understand what causes it. In most cases, no specific underlying cause is found. In other cases, underlying diseases or exposures likely contributed to the development of moyamoya, including sickle cell anemia, past radiation therapy to the brain, atherosclerosis, neurofibromatosis, and others. 

In adults, the following vascular risk factors may contribute:

  • Smoking
  • Diabetes
  • High blood pressure
  • High cholesterol
  • Atherosclerosis (hardening of the arteries)

These risk factors may cause the narrowing, leading to the development of moyamoya symptoms.

Diagnosing Moyamoya

When you come to Barnes-Jewish after a stroke/TIA, our neurologists,neurosurgeons and neurointerventional surgeons use magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA) and cerebral angiography to look at your blood vessels and identify why you had the stroke. For children, these tests can be performed by a pediatric neurologist.

Cerebral angiography is an X-ray study of the blood vessels using a dye. It shows the narrowing of the carotid arteries, as well as the formation and disappearance of the moyamoya vessels. 

MRI/MRA is a noninvasive imaging technique that shows the blockage of the arteries and moyamoya vessels on both sides. It can reveal whether the patient has had a stroke/TIA, which are clear symptoms of moyamoya. 

Moyamoya Treatment

All moyamoya treatment options are available at Barnes-Jewish Hospital, a partner of Washington University School of Medicine. We use advanced perfusion imaging (MRI perfusion or CT perfusion), which is critical to understanding the severity of the moyamoya and selecting the best treatment option. This technology is offered at very few places in the United States.

Moyamoya has varying degrees of severity, so not every patient needs surgery immediately. For patients with little to no symptoms, moyamoya is often managed with medication to control your risk factors. Patients with vascular risk factors often are best treated with medication alone to manage the cause, such as diabetes or hypertension. For patients who have suffered a stroke or brain hemorrhage, surgical procedures designed to improve blood flow to the brain are often recommended.

Our specialists collaborate to determine if surgery is the right treatment for you. For adults, a vascular neurosurgeon with special expertise in bypass surgery will perform the surgery. For children, a pediatric neurosurgeon and vascular neurosurgeon often perform the surgery together.

Moyamoya Surgery

If surgery is recommended for moyamoya, Washington University’s highly experienced neurosurgeons offer the following options:

  • STA-MCA bypass surgery (superficial temporal artery to middle cerebral artery bypass  surgery) can be performed in adult moyamoya patients. It provides an immediate increase of blood flow in the brain by rerouting the arteries from the scalp to the brain. Barnes-Jewish performs 10 to 12 STA-MCA bypasses each year. This high volume leads to greater experience in performing the procedure resulting in better outcomes. 
  • An indirect revascularization procedure is usually performed in children. This moyamoya surgery involves laying an artery or muscle on the surface of the brain. It leads to blood vessel formation and increase blood flow to the brain over a period of time. 
  • Encephaloduroarteriosynangiosis (EDAS) involves laying of the main scalp arteries, usually the STA, directly on the surface of the brain. Over several months, this causes the growth of new arteries in the brain and provides more blood flow. Once an EDAS is performed, the STA cannot be used for a direct bypass procedure.
  • Encephalomyosynangiosis (EMS) involves taking the temporalis muscle, which is in the temple region of the forehead, opening the skull and placing the muscle on the brain. Similar to EDAS, this procedure results in the development of arteries and increased blood flow over months.

For a referral to a Washington University neurologist or neurosurgeon at Barnes-Jewish Hospital, call 888.526.7839.

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