Moyamoya Disease

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What is moyamoya disease?

Moyamoya disease is a rare, progressive cerebrovascular disorder caused by blocked arteries at the base of the brain in an area called the basal ganglia. Moyamoya means “puff of smoke” in Japanese and is used to describe the tangled appearance of tiny vessels compensating for the blockage.  

Moyamoya disease was first described in Japan and is found in individuals around the world, although its incidence is higher in Asian countries than in Europe or North America. The disease primarily affects children, but can also occur in adults.

In children, the first symptom of moyamoya disease is often stroke or recurrent transient ischemic attacks (TIAs), also known as “mini-strokes," that are frequently accompanied by muscular weakness or paralysis affecting one side of the body. Adults may also experience these symptoms that arise from blocked arteries, but more often experience a hemorrhagic stroke due to bleeding into the brain. Other symptoms may include:

  • Headaches
  • Seizures
  • Disturbed consciousness
  • Involuntary movements
  • Vision problems
  • Cognitive and/or sensory impairment

Some individuals have a close relative who is also affected; in these cases, researchers think the disease is the result of inherited genetic abnormalities.

Medications may be prescribed to reduce the risk of stroke. Several types of surgery can restore blood flow (revascularization) to the brain by opening narrowed blood vessels or by bypassing blocked arteries. Some individuals have no further strokes or related problems after surgery.

Without surgery, the majority of individuals with moyamoya disease will experience mental decline and multiple strokes because of the progressive narrowing of arteries. Without treatment, moyamoya disease can be fatal as the result of intracerebral hemorrhage (bleeding within the brain).

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Learn About Clinical Trials
Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

How can I or my loved one help improve care for people with moyamoya disease?

Consider participating in a clinical trial so clinicians and scientists can learn more about moyamoya disease and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with moyamoya disease at Clinicaltrials.gov.

Where can I find more information about moyamoya disease?

Information may be available from the following resources:

Children's Hemiplegia and Stroke Association (CHASA)

National Rehabilitation Information Center (NARIC)

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The NINDS Publication Catalog offers printed materials on neurological disorders for patients, health professionals, and the general public. All materials are free of charge, and a downloadable PDF version is also available for most publications.