[An adult case of moyamoya disease associated with marked advance of occlusive lesion in the bilateral carotid system].

We reported an adult case with moyamoya disease in which unilateral obstructive process proceeded to the bilateral lesion during a period of 45 months. A 30-year-old female was admitted to our institute due to frequent ischemic episodes since she was 25 years old. At the time of admission, she was asymptomatic with slightly disturbed psychogenic reactions. At the time of the initial cerebral angiography when she was 25 years old, the right cerebral angiography demonstrated stenosis of the right ICA terminal portion with moyamoya vessels in the basal area and leptomeningeal anastomosis at the right parietal area. The left cerebral angiography revealed normal ICA system with a lightly narrowing Al portion, without Moyamoya vessels. The second cerebral angiography, taken 45 months after the initial angiography, demonstrated progression stenosis of the right ICA terminal portion, with decreasing moyamoya vessels at the basal area, obstruction of the left ICA terminal portion, stenosis at the Al portion with newly developed moyamoya vessels in the left basal area. We concluded at this time that this case was a definite case of moyamoya disease. The third cerebral angiography after right SDP (synangio-dural plasty), 49 months after the initial angiography, revealed, in the right angiography, newly formed anastomotic vessels perfusing the middle cerebral artery region via the extracerebral arteries and in the left cerebral angiography, and an increased obstruction of the ICA terminal portion, transdural anastomosis via the extracerebral arterial system, and a decrease of moyamoya vessels in the basal area. This rare case provided us a good picture of the pathogenic mechanism of moyamoya disease.