CHOC Children's

Moyamoya Disease

What is Moyamoya Disease?

Moyamoya disease is a rare, progressive cerebrovascular disorder characterized by the narrowing or occlusion of major blood vessels leading into the brain, and the formation of abnormal blood vessels called moyamoya vessels. First described in Japan in the 1960s, the disease has since been found in the United States, Europe, Australia, and Africa. It primarily affects children, adolescents, and young adults, although it has also been seen in people beyond these ages. Females are more frequently affected than males. The cause of the disease is unknown. Researchers suspect a genetic link because of the high incidence of the disease found in certain Japanese families. The name "moyamoya" is Japanese for "cloud of smoke" and was chosen to describe the classic appearance of the abnormal vessels seen in diagnostic tests. Children often present with stroke or recurrent transient ischemic attacks (TIAs), frequently accompanied by hemiparesis (muscular weakness or paralysis affecting one side of the body) or seizures. Adults most often experience stroke (often a hemorrhage). Both children and adults may have disturbed consciousness, speech deficits (aphasia), sensory and cognitive impairments, involuntary movements, and vision problems. Generally, cerebral angiography - a procedure that involves injecting dye into the cerebral arteries before taking an x-ray to make the arteries easier to see - is used to diagnose moyamoya disease.

Is there any treatment?

There is no cure for moyamoya disease. Treatment is symptomatic and supportive. Individuals experiencing TIAs and stroke may be given aspirin, vasodilators, or anticoagulants to reduce the risk of future attacks. There are several different types of revascularization (restoration of blood supply) surgery that may be performed in some cases. Children usually respond better to revascularization surgery than adults.

What research is being done?

Within the NINDS research programs, moyamoya disease is addressed primarily through studies associated with TIA and stroke. NINDS is the leading supporter of research on stroke and TIA in the United States and sponsors studies ranging from clinical trials to investigations of basic biological mechanisms.

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