Moyamoya disease

What causes Moyamoya disease?

In some families, risk for moyamoya disease is inherited. Changes in the RNF213 gene have been associated with the condition. There are other gene changes involved in moyamoya disease, that remain to be found. Factors such as infection or inflammation, likely also play a role in the condition's development in these families.

Other people develop moyamoya _syndrome or _phenomenon__. Moyamoya syndrome can occur in association with many different conditions, such as with infections, atherosclerosis (clogged arteries), blood disorders (for example sickle cell disease or beta thalassemia), vasculitis, autoimmune conditions (for example Lupus, thyroid disorders, Sneddon syndrome), connective tissue disorders (for example neurofibromatosis (NF) type 1 or Tuberous sclerosis), chromosome disorders, metabolic diseases, head trauma or radiation, brain tumors, and heart disease, to name a few.

Last updated on 05-01-20

What is the long-term outlook for people with Moyamoya disease?

Moyamoya disease is progressive and without treatment can be fatal due to intracerebral hemorrhage. Without surgery, the majority of affected people experience recurrent strokes and gradual deterioration of cognitive function. In studies with long-term follow-up of untreated patients, progressive neurologic deficits and poor outcome were reported in 50 to 66 percent.The overall mortality rate from Moyamoya disease is about 10% in adults, and 4.3% in children.

Last updated on 05-01-20

How might Moyamoya disease be treated?

Treatment for Moyamoya disease should begin early in the disease course to prevent severe complications. Surgery is the mainstay of treatment, and is the only viable long-term treatment. There are several types of revascularization surgeries that can restore blood flow to the brain by opening narrowed blood vessels, or by bypassing blocked arteries. While children usually respond better to revascularization surgery than adults, the majority of individuals have no further strokes or related problems after surgery.

No medication can stop the narrowing of the brain's blood vessels, or the development of the thin, fragile vessels that characterize the disease. However, medications are used to treat many of the symptoms of the disease, and are often an important part of the management. Medications may include aspirin (to prevent or reduce the development of small blood clots); calcium channel blockers (which may improve symptoms of headaches and reduce symptoms related to transient ischemic attacks); and anti-seizure medications (when needed for a seizure disorder). In a few cases, anticoagulants may be needed for people with unstable or frequent symptoms. However, they are not used long-term due to the risk of cerebral bleeding.

Additional information about the treatment of Moyamoya disease is available on Medscape Reference's Web site.

People interested in learning about specific treatment options for themselves or family members should speak with their health care provider.

Last updated on 05-01-20

Where To Start

Moyamoya disease

The Boston Children's Hospital website provides information on pediatric moyamoya disease. Click on Boston Children's Hospital to view this resource.

Last updated on 04-27-20

Stanford Moyamoya Center

Stanford Moyamoya Center has a page for frequently asked questions and answers for patients and families.

Last updated on 04-27-20


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The RareGuru disease database is regularly updated using data generously provided by GARD, the United States Genetic and Rare Disease Information Center.

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