Houston Methodist. Leading Medicine.
Houston Methodist. Leading Medicine

MoyaMoya Disease


Moyamoya Disease

The neurosurgeons at Houston Methodist Hospital Neurological Institute Cerebrovascular Center diagnose and treat many kinds of cerebrovascular conditions, including rare brain disorders such as moyamoya disease (also called moyamoya syndrome). Because the condition is rare, Houston Methodist is one of the few places in the world offering a depth of experience and specialization to treat moyamoya disease.


Moyamoya, Japanese for “puff of smoke,” describes the tangle of tiny blood vessels that characterize this disease. Moyamoya is a progressive disease where the arteries at the base of the brain become blocked. To compensate for the blockage, tiny blood vessels grow in a wispy, tangled mass.

Moyamoya disease usually affects children. It can show up in adults, often presenting as a stroke or hemorrhage (bleeding), which can be fatal. Left untreated, moyamoya disease can cause multiple strokes that lead to neurological decline, severe brain damage, and death.


In children, moyamoya may cause:

  • Transient ischemic attacks (TIAs or “mini strokes”)
  • Seizures
  • Headaches
  • Developmental delays
  • Speech problems
  • Uncontrollable movements, or an inability to move arms, legs, or feet
  • Anemia (low iron in the blood)

In adults, moyamoya symptoms include:

  • Bleeding
  • Stokes
  • Fainting or “blacking out”
  • Poor or blurry vision, vision loss in one eye, or inability to recognize objects


If moyamoya disease is suspected, it’s important to diagnose it as quickly as possible to prevent complications like stroke and disability. If you or your child may have moyamoya disease, the neurosurgeons at Houston Methodist Neurological Institute Cerebrovascular Program may suggest one or more of the following imaging scans and tests:

  • Magnetic resonance imaging (MRI), which can detect blocked blood vessels
  • Computed tomography (CT) scan, which can also detect blocked blood vessels
  • Angiogram, which can confirm diagnosis and show the structure of the affected blood vessels
  • Single photo emission computerized tomography (SPECT), which is a nuclear medicine technique that can show if the brain has reduced blood or oxygen supplies

Treatment Options

Surgery is the only treatment for moyamoya disease. Neurosurgeons at Houston Methodist Neurological Institute Cerebrovascular Center perform several types of revascularization surgeries that open narrow blood vessels, bypass blocked arteries, and restore blood flow to the brain.

Direct Revascularization (STA-MCA Bypass)

This surgery connects a branch of the scalp artery (STA) to a branch of the brain artery (MCA) on the outer surface of the brain. This improves the brain’s blood supply right away. This microsurgical procedure is also called an extracranial to intracranial bypass graft (EC-IC bypass).

Children under age five may not be good candidates for this procedure because their arteries are often too small to bypass.

Encephalo-duro-arterio-synangiosis (EDAS)

EDAS is a surgery that supplies new blood flow to the brain indirectly. In this procedure, a branch of the superficial temporal artery is laid on the surface of the brain. This artery will usually grow new arteries into the brain to provide more blood flow in about six to eight weeks.

This procedure may be done when a direct graft is not possible. Children are often better candidates than adults.

Encephalo-myo-synangiosis (EMS)

EMS is another indirect bypass surgery. In this procedure, the neurosurgeon frees a muscle from the patient’s temple area, directs it through a hole in the skull, and places the muscle onto the surface of the brain. A new blood supply to the brain will develop in about six to eight weeks.

Encephalo-duro-arterio-myo-synangiosis (EDAMS)

EDAMS combines both EDAS and EMS procedures.

Omental Transposition

The omentum, the lining that surrounds the abdominal organs, has a rich blood supply. This procedure places the omentum onto the surface of the brain to generate new vessels to supply blood to the brain.

Multiple Burr Holes

In this indirect revascularization procedure, several small holes (burr holes) are drilled into the skull. This allows blood vessels from the scalp to grow into the brain to provide a new blood supply.


There is no drug available to treat moyamoya disease. However, some medications are used to treat side effects or prevent complications. These should only be used under a neurosurgeon’s supervision.

  • Aspirin or other anticoagulants may be used to help prevent blood clots from forming, which can help prevent strokes.
  • Calcium channel blockers may be used to help lower blood pressure and reduce headaches.

Recovery and Rehabilitation

Recovery depends on many factors, such as how far moyamoya disease has progressed before treatment, the patient’s overall health status, and how quickly revascularization (new blood supply) takes place.

Generally, patients are in the hospital three to five days, and can often resume their regular activities after two to six weeks of recovery. Even though symptoms may improve right away after treatment, it can take six to 12 months for new vessels to develop completely.

Additional Resources