A 2005 review result suggest an incidence of 0.086 cases per 100,000 people in the U.S. MMD is the most common pediatric cerebrovascular disorder in Japan, with a prevalence of about three cases per 100,000 children, while the incidence in Europe is approximately one- tenth of that observed in Japan. There are almost twice as many female patients as there are male. The incidence of MMD peaks in two age groups: int those around 4 years-old (pediatric MoyaMoya Disease, pMMD), and those in their 40s (adult MoyaMoya Disease, aMMD). Although it is more common in Japan, clinical cases of the pathology have been reported in other parts of the world. MMD was first described in Japan in 1957 by Takeuchi and Shimizu.
The aetiology is unclear, but is perhaps related to an acquired lesion of the blood vessels at the brain’s base. Moyamoya disease (MMD) is a rare vascular syndrome most commonly found among the Japanese and other Asiatic peoples, its is chareacterized by the angiographic appearance of widespread cerebral collaterals due to occlusion of one or both internal carotid arteries.
