[Progressive occlusive disease of cerebral arteries associated with Down's syndrome. Report of a case].

The case of a 5 years old child with association of "moyamoya" and Down syndrome with permeability of internal carotid, of medial and anterior cerebral arteries is reported. The authors postulate the possibility of a microcirculatory disorder in view of the distal lesion including the action of any unknown substance which constrictive action could explain the bilaterality and distribution of the alterations.