Moyamoya disease is a rare blood vessel (vascular) disorder in which a ring of blood vessels at the base of your brain (the circle of Willis) and the uppermost (distal) segments of the arteries supplying the brain progressively narrow, causing blood flow to your brain to become reduced.

The condition may cause a ministroke (transient ischemic attack), stroke or other symptoms.

Moyamoya disease mainly affects children, but adults may have the condition. Moyamoya disease usually occurs in people from Japan and other Asian countries, but people in North America, Europe and other areas also have moyamoya disease.

  • Experience. Mayo Clinic doctors trained in brain conditions (neurologists) and brain surgery (neurosurgeons) have experience treating people with moyamoya disease and other brain and blood vessel conditions (cerebrovascular diseases).

    Moyamoya disease generally occurs in less than 1 person in 100,000. Mayo Clinic doctors evaluate and treat more than 50 people each year with moyamoya disease.

  • Team approach. Mayo Clinic neurologists, neurosurgeons, neuroradiologists and others work together to evaluate and treat people with moyamoya disease.
  • Treatment expertise. Mayo Clinic surgeons have expertise treating moyamoya disease using many sophisticated surgical techniques.

Mayo Clinic in Rochester, Minn., is ranked among the Best Hospitals for neurology and neurosurgery and for heart and heart surgery by U.S. News & World Report. Mayo Clinic also ranks among the Best Children's Hospitals in neurology and neurosurgery and for heart and heart surgery.

At Mayo Clinic, we assemble a team of specialists who take the time to listen and thoroughly understand your health issues and concerns. We tailor the care you receive to your personal health care needs. You can trust our specialists to collaborate and offer you the best possible outcomes, safety and service.

Mayo Clinic is a not-for-profit medical institution that reinvests all earnings into improving medical practice, research and education. We're constantly involved in innovation and medical research, finding solutions to improve your care and quality of life. Your doctor or someone on your medical team is likely involved in research related to your condition.

Our patients tell us that the quality of their interactions, our attention to detail and the efficiency of their visits mean health care — and trusted answers — like they've never experienced.

Why Choose Mayo Clinic

What Sets Mayo Clinic Apart

Mayo Clinic doctors trained in brain conditions (neurologists) and brain surgery (neurosurgeons) diagnose moyamoya disease.

To diagnose moyamoya disease, your doctor will review your symptoms and your family and medical history. Your doctor will perform a physical examination and order several tests to diagnose moyamoya disease and any underlying conditions.

Tests may include:

  • Magnetic resonance imaging (MRI). An MRI uses powerful magnets and radio waves to create detailed images of your brain.

    Your doctor may inject a dye into a blood vessel to view your arteries and veins and highlight blood circulation (magnetic resonance angiogram).

  • Computerized tomography (CT) scan. A CT scan uses a series of X-rays to create a detailed image of your brain.

    Your doctor may inject a dye into a blood vessel to highlight blood flow in your arteries and veins (CT angiogram).

  • Cerebral angiogram. In a cerebral angiogram, your doctor inserts a long, thin tube (catheter) into a blood vessel in your groin and guides it to your brain using X-ray imaging.

    Your doctor then injects dye through the catheter into the blood vessels of your brain to make them visible under X-ray imaging.

  • Transcranial Doppler ultrasound. In a transcranial Doppler ultrasound, sound waves are used to obtain images of your neck. Doctors may use this test to evaluate blood flow in blood vessels in your neck.
  • Positron emission tomography (PET) scan or single-photon emission computerized tomography (SPECT). In these tests, your doctor injects you with a small amount of radioactive material and places emission detectors on your brain. PET provides visual images of brain activity. SPECT measures blood flow to various regions of your brain.

Mayo Clinic doctors trained in brain conditions (neurologists) and brain surgery (neurosurgeons) work together to treat people with moyamoya disease.

Doctors will evaluate your condition and determine the most appropriate treatment for your condition. The goal of treatment is to reduce your symptoms, improve your blood flow and lower your risk of serious complications such as strokes, bleeding in your brain (intracerebral hemorrhages) or death.

Your treatment may include:

Medication

After you're diagnosed with moyamoya disease, if you have mild or no symptoms at first, then your doctor may recommend you take aspirin to prevent strokes. Consider giving your child over-the-counter pain medications such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin, others) to ease symptoms.

Revascularization surgery

If your symptoms become worse or if tests show evidence of low blood flow, your doctor may recommend revascularization surgery.

In revascularization surgery, surgeons bypass blocked arteries to help restore blood flow to your brain. Mayo Clinic doctors may use direct or indirect revascularization procedures, or a combination of both.

  • Direct revascularization procedures. In direct revascularization surgery, surgeons stitch (suture) the scalp artery directly to a brain artery (superficial temporal artery to middle cerebral artery bypass surgery) to increase blood flow to your brain immediately.

  • Direct bypass surgery may be difficult to perform in children, due to the size of the blood vessels to be attached.

    Direct revascularization surgery has a risk of complications such as stroke.

  • Indirect revascularization procedures. Indirect revascularization includes several options. In indirect revascularization, the goal is to increase blood flow to your brain gradually over time. Indirect revascularization may have fewer complications and take less time to conduct than does direct revascularization.

    In encephaloduroarteriosynangiosis (EDAS), your surgeon separates (dissects) a scalp artery over several inches.

    Your surgeon makes a small temporary opening in your skull directly beneath the artery and attaches (sutures) the intact scalp artery to the surface of your brain, which allows blood vessels from the artery to grow into your brain over time. The surgeon then replaces the bone and closes the opening in your skull.

    In encephalomyosynangiosis (EMS), your surgeon separates (dissects) a muscle in the temple region of your forehead and places it onto the surface of your brain through an opening in your skull to help restore blood flow.

    Your surgeon may perform EMS with EDAS. In this procedure, your surgeon separates (dissects) a muscle in the temple region of your forehead and places it onto the surface of your brain, after attaching the scalp artery to the surface of your brain. The muscle helps to hold the artery in place as blood vessels grow into your brain over time.

    Your surgeon may remove a portion of a fatty layer of tissue from the abdominal area, place it onto the surface of your brain, and attach the scalp artery to the blood vessel of the fatty layer (omental transplant). This procedure may restore blood flow to your brain.

    Your surgeon may make multiple holes (burr holes) in your skull to allow new blood vessels to grow, either as a separate procedure or in combination with other procedures.

    Your doctor may use other combinations of direct and indirect revascularization procedures depending on your needs.

Mayo Clinic works with hundreds of insurance companies and is an in-network provider for millions of people. In most cases, Mayo Clinic doesn't require a physician referral. Some insurers require referrals or may have additional requirements for certain medical care. All appointments are prioritized on the basis of medical need.

Doctors trained in neurology and neurosurgery treat adults with moyamoya disease at Mayo Clinic in Arizona.

For appointments or more information, call the Central Appointment Office at 800-446-2279 (toll-free) 8 a.m. to 5 p.m. Mountain Standard Time, Monday through Friday or complete an online appointment request form.

Doctors trained in neurology and neurosurgery treat adults with moyamoya disease at Mayo Clinic in Florida.

For appointments or more information, call the Central Appointment Office at 904-953-0853 8 a.m. to 5 p.m. Eastern time, Monday through Friday or complete an online appointment request form.

Doctors trained in neurology and neurosurgery treat people with moyamoya disease at Mayo Clinic in Minnesota.

For appointments or more information, call the Central Appointment Office at 507-538-3270 7 a.m. to 6 p.m. Central time, Monday through Friday or complete an online appointment request form.

Doctors trained in pediatric neurology and neurosurgery treat children with moyamoya disease at Mayo Clinic in Minnesota. Children needing hospitalization receive care at Mayo Eugenio Litta Children's Hospital at Mayo Clinic in Minnesota.

For appointments or more information, call the Central Appointment Office at 507-538-3270 7 a.m. to 6 p.m. Central time, Monday through Friday or complete an online appointment request form.

See information on patient services at the three Mayo Clinic locations, including transportation options and lodging.

Mayo Clinic doctors trained in brain conditions (neurologists) and brain surgery (neurosurgeons) research potential diagnostic tests and treatments for moyamoya disease and other neurological conditions. Learn more about research in neurology and neurosurgery.

See a list of publications by Mayo doctors on moyamoya disease on PubMed, a service of the National Library of Medicine.

  1. Fredric B. Meyer, M.D.
  2. Nicholas M. Wetjen, M.D.
Mar. 22, 2014