THE DISEASE which produces an abnormal net-like blood vessel picture (hereinafter referred to as "moyamoya" [a Japanese expression for something hazy just like a puff of cigarette smoke drifting in the air]) in the base of the brain might have been observed in our country during these 10 years. However, visualization of such an angiogram seems not to have been noticed as indicating a disease with characteristic features.
In this disease, a stenosis or an occlusion is observed by carotid arteriography in the terminal part of the internal carotid artery. Furthermore, a net-like or fibrous-root-like dim picture of abnormal blood vessels is visualized over it. In some cases, there is a defect or an abnormality observed in the median or anterior cerebral artery. Under certain circumstances, the whole main arteries of the brain fall off from an angiogram. This disease appears bilaterally in most cases, although there are some differences