About Moyamoya Disease



In 1950's, Japanese leading neurosurgeons at that time began to notice the new clinical entity of moyamoya disease. Since its etiology was unknown, it was named in various ways, such as moyamoya disease, chiri-chiri disease, etc. Moyamoya disease is now officially named in Japan as "the spontaneous occlusion of the circle of Willis."

The terminal portions of the intracranial internal carotid arteries progressively become stenotic (narrowing) or occlusive. Due to reduced blood flow to the brain, tiny collateral vessels at the base of the brain enlarge to become as collateral pathways. These vessels are called "moyamoya vessels" because the angiographic appearance of these vessels resemble the "cloud" or "puff" of the cigarette smoke, which is described as "moya-moya" in Japanese language (Suzuki J, Takaku A, 1969).

About the name of moyamoya disease

Moyamoya Vessels (Abnormally proliferating arteries?)

In 1960's, moyamoya disease became the main interest for the neurosurgeons and neurologists because this disease was prevalent solely in Japan and/or Japanese ethnicity. In 1994, the number of the annual patients having moyamoya disease was estimated about 3,900.

Normal cerebral angiogram and that of moyamoya patient


Symptoms of moyamoya disease include brain ischaemia and hemorrhage. There are two peaks in age distribution: below 10 and at 30-40 years old, with the highest peak in the first decade and lower peak in the adults. Under the age of 10, brain ischemia (transient ischemic attack and cerebral infarction) is common whilst brain hemorrhage is more common at the age of 30-40 years old.

Age Distribution of Moyamoya Disease

Incidence of moyamoya disease among females is 1.8 times more than that among males. Although there have been many reports on moyamoya disease all over the world including Asia, Europe, Australian, and the United States, it is most common among Japanese.

About Korean Moyamoya Disease

Worldwide Distribution of Moyamoya Disease

Its etiology is still unknown, although some investigators regard it as cerebral arteritis. Moyamoya disease was initially though to be congenital. It had been believed in 1980's that antecedent infection causes the disease (acquired theory). However, about 10% of familial incidence of the disease and high incidence among Japanese indicate congenital factors contributing to the disease (congenital theory). It is believed now that some moyamoya disease have multiple genetic factors.

Brain ischemia includes transient ischemic attacks (TIAs) and cerebral infarction. The former means that all symptoms disappear within 24 hours, but commonly within 15-30 minutes. When whistling, puffing hot soup, playing a flute, cerebral arteries become spastic leading to cerebral ischaemia. Altered consciousness, weakness of the extremities, weakness of one side of the body, speech disturbance (aphasia), involuntary movements, headache, convulsion, sensory abnormality, visual disturbance or mental alteration may be observed.

When brain hemorrhage occurs, according to the location and size of the hemorrhage, the patients develop altered consciousness, weakness of arms and legs, sensory disturbance, convulsion (seizure), or mental alteration. If hemorrhage is large enough, it is occasionally fatal.


When you first heard of the name of "moyamoya disease"

General information of moyamoya disease