Moyamoya disease

a cerebrovascular disorder occurring predominantly in the Japanese, in which the vessels of the base of the brain become occluded and revascularized with a fine network of vessels

Description
Moyamoya disease commonly occurs in young children and is manifested by convulsions, hemiplegia, mental retardation, and subarachnoid hemorrhage; the diagnosis is made by the angiographic picture. A similar picture is seen in some patients with sickle cell disease.