[Moyamoya disease].

Moya-moya is a rare cerebrovascular disease characterized by the progressive occlusion of cerebral vessels with partial switching off the circle of Willis and arteries that feed it. The article provides a review of literature, modern diagnostic criteria and a description of a single clinical case. The onset of the disease in this patient was characterized by headache and speech disorders.An analysis of speech disorders showed that they were systemic. They were registered at all language levels (phonetic, lexical,morphological, syntactic). A long diagnostic search may be explained by clinical manifestations that are atypical for other cerebrovascular diseases and by the rarity of the disease.