moyamoya disease definition
Moyamoya disease is a rare, progressive cerebrovascular disorder caused by blocked arteries at the base of the brain in an area called the basal ganglia. The name âmoyamoyaâ means âpuff of smokeâ in Japanese and describes the look of the tangle of tiny vessels formed to compensate for the blockage.oyamoya disease is a rare, progressive cerebrovascular disorder caused by blocked arteries at the base of the brain in an area called the basal ganglia. The name âmoyamoyaâ means âpuff of smokeâ in Japanese and describes the look of the tangle of tiny vessels formed to compensate for the blockage.