Moyamoya disease developing from unilateral moyamoya disease--case report.

The authors report a case of unilateral moyamoya disease which developed into moyamoya disease 3 years later. Unilateral moyamoya disease is generally defined as moyamoya disease, but the exact relationship is unknown. In this case, occlusive changes developed in the stenotic carotid fork, and in a similar portion contralaterally which was intact. Follow-up 4-vessel angiography is strongly recommended even for unilateral moyamoya disease.