National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Moyamoya disease


Other Names:
Moyamoya syndrome; Spontaneous occlusion of the circle of Willis; MYMY
Categories:
Moyamoya disease is a rare, progressive, blood vessel disease caused by blocked arteries at the base of the brain in an area called the basal ganglia. The name "moyamoya" means "puff of smoke" in Japanese and describes the look of the tangled vessels that form to compensate for the blockage. This condition usually affects children, but can affect adults. Affected people are at increased risk for blood clots, strokes, and transient ischemic attacks (TIAs) which are frequently accompanied by seizures and muscular weakness, or paralysis on one side of the body. Affected people may also have disturbed consciousness, speech deficits (usually aphasia), sensory and cognitive impairments, involuntary movements, and vision problems. Researchers believe that Moyamoya disease is an inherited condition because it tends to run in families.[1]

Moyamoya syndrome is a related term that refers to cases of moyamoya disease that occur in association with other conditions or risk factors, such as neurofibromatosis, tuberculosis meningitis, sickle cell disease, leptospirosis, brain tumors, Sturge-Weber syndrome, and tuberous sclerosis.[2]

Last updated: 7/1/2014

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Telangiectasia 0001009
30%-79% of people have these symptoms
Abnormality of the cerebral vasculature
Abnormality of the cerebral blood vessels
0100659
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Seizure 0001250
Ventriculomegaly 0002119
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance 0000007
Carotid artery occlusion
Obstructed carotid artery
0012474
Inflammatory arteriopathy 0005291
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Last updated: 7/1/2020
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.[3]

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.[3]
Last updated: 7/27/2015
Treatment for Moyamoya disease should begin early in the disease course to prevent severe complications.[4] Surgery is the mainstay of treatment, and is the only viable long-term treatment.[5] 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.[6]

No medication can stop the narrowing of the brain's blood vessels, or the development of the thin, fragile vessels that characterize the disease.[5] 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.[7]

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: 7/1/2014

Management Guidelines

  • Project OrphanAnesthesia is a project whose aim is to create peer-reviewed, readily accessible guidelines for patients with rare diseases and for the anesthesiologists caring for them. The project is a collaborative effort of the German Society of Anesthesiology and Intensive Care, Orphanet, the European Society of Pediatric Anesthesia, anesthetists and rare disease experts with the aim to contribute to patient safety.
Moyamoya disease is progressive and without treatment can be fatal due to intracerebral hemorrhage.[6] Without surgery, the majority of affected people experience recurrent strokes and gradual deterioration of cognitive function.[8] In studies with long-term follow-up of untreated patients, progressive neurologic deficits and poor outcome were reported in 50 to 66 percent.[9]The overall mortality rate from Moyamoya disease is about 10% in adults, and 4.3% in children.[8]
Last updated: 7/1/2014

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
MMD may develop in an isolated manner but can also be associated with other diseases when it is known as MMS: typical angiographic MMDfeatures associated with other diseases, e.g. sickle cell anemia, Down syndrome, neurofibromatosis type 1 (see these terms) and many others.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The Centers for Mendelian Genomics program is working to discover the causes of rare genetic disorders. For more information about applying to the research study, please visit their website.
  • ClinicalTrials.gov lists trials that are related to Moyamoya disease. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.
  • Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition. 
  • The Research Portfolio Online Reporting Tool (RePORT) provides access to reports, data, and analyses of research activities at the National Institutes of Health (NIH), including information on NIH expenditures and the results of NIH-supported research. Although these projects may not conduct studies on humans, you may want to contact the investigators to learn more. To search for studies, enter the disease name in the "Text Search" box. Then click "Submit Query".

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • MeSH® (Medical Subject Headings) is a terminology tool used by the National Library of Medicine. Click on the link to view information on this topic.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Moyamoya disease. Click on the link to view a sample search on this topic.

Videos/Presentations

  • The Boston Children's Hospital has live videos on Moyamoya disease. Click on Boston Children's Hospital to choose a video to watch.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. NINDS Moyamoya Disease Information Page. National Institute of Neurological Disorders and Stroke (NINDS). March 2011; https://www.ninds.nih.gov/Disorders/All-Disorders/Moyamoya-Disease-Information-Page. Accessed 9/19/2011.
  2. Smith ER & Scott RM. Moyamoya: epidemiology, presentation, and diagnosis. Neurosurg Clin N Am. July 2010; http://www.ncbi.nlm.nih.gov/pubmed/20561502. Accessed 9/19/2011.
  3. Suwanwela NC. Moyamoya disease: Etiology, clinical features, and diagnosis. In: Biller J, Nordli DR. UpToDate. Waltham, MA: UpToDate; 2015; Accessed 7/27/2015.
  4. Josette Mancini. Moyamoya Disease. Orphanet. September, 2006; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=2573. Accessed 7/2/2014.
  5. Edward Smith. Moyamoya Disease. Boston Children's Hospital. 2011; http://www.childrenshospital.org/health-topics/conditions/m/moyamoya-disease. Accessed 7/2/2014.
  6. Moyamoya Disease Information Page. NINDS. April 16, 2014; https://www.ninds.nih.gov/Disorders/All-Disorders/Moyamoya-Disease-Information-Page. Accessed 7/1/2014.
  7. Moyamoya syndrome. NORD. January 20, 2012; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/617/viewAbstract. Accessed 7/2/2014.
  8. Roy Sucholeiki. Moyamoya Disease. Medscape Reference. January 25, 2012; http://emedicine.medscape.com/article/1180952-overview. Accessed 7/1/2014.
  9. Nijasri Charnnarong Suwanwela. Moyamoya disease: Treatment and prognosis. UpToDate. Waltham, MA: UpToDate; July, 2014; Accessed 7/2/2014.
  10. Fernandez-Alvarez E, Pineda M, Royo C, Manzanares R. "Moya-moya' disease caused by cranial trauma. Brain Dev. 1979; 1(2):133. Accessed 7/27/2015.
  11. Moyamoya disease. Genetics Home Reference. April 2015; http://ghr.nlm.nih.gov/condition/moyamoya-disease. Accessed 7/27/2015.