Moyamoya syndrome in young children: MR comparison with adult onset.

PURPOSE To clarify whether there were any differences in MR appearance between the childhood and the adult moyamoya syndromes. METHOD We compared the cranial MR findings in four children under the age of 6 who had moyamoya syndrome with previously documented adult cases. RESULTS Moyamoya syndrome in younger children exhibited a significant increase in cortical and subcortical infarction, and a decreased incidence of deep white matter infarction in the centrum semiovale and basal ganglia, in contrast to adult cases. There were no remarkable differences between these two groups of moyamoya cases with regard to the occlusive changes of the internal carotid and middle cerebral arteries, or to the flow void sign on MR. CONCLUSION These differences in the sites and frequencies of infarctions between the childhood and the adult moyamoya syndromes observed on MR might reflect differences in the cerebral circulation.