[Transdural anastomosis in a juvenile form of moyamoya disease].

Moya-Moya disease has a low prevalence and world-wide distribution, with greater incidence in the first 5 years of life (juvenile form) or in the third decade (adult form). Stenosis of the intracranial portion of the internal carotid artery leads to secondary establishment of intracranial compensating anastamoses at different levels (leptomeninges, basal ganglia and transdural). We present the case of a 7 year old boy who presented clinically with choreiform movements and later had a cerebral infarct. On angio-MR and MR studies we observed the typical smoky image together with development of additional compensatory transdural anastomoses from the superficial temporal and ophthalmic arteries to the anterior and middle cerebral arteries.