What is (are) Moyamoya Disease ?
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 moyamoya means puff of smoke in Japanese and describes the look of the tangle of tiny vessels formed to compensate for the blockage. Moyamoya disease was first described in Japan in the 1960s and it has since been found in individuals in the other countries around the world; its incidence is higher in Asian countries than in Europe or North America. The disease primarily affects children, but it can also occur in adults. In children, the first symptom of Moyamoya disease is often stroke, or recurrent transient ischemic attacks (TIA, commonly referred to as mini-strokes), frequently accompanied by muscular weakness or paralysis affecting one side of the body, or seizures. Adults may also experience these symptoms that arise from blocked arteries, but more often experience a hemorrhagic stroke due to bleeding into the brain from the abnormal brain vessels. Individuals with this disorder may have disturbed consciousness, problems with speaking and understanding speech, sensory and cognitive impairments, involuntary movements, and vision problems.About one in 10 individuals with Moyamoya disease has a close relative who is also affected; in these cases researchers think that Moyamoya disease is the result of inherited genetic abnormalities.Studies that look for the abnormal gene(s) may help reveal the biomechanisms that cause the disorder.