Moyamoya Disease:The Differences between Age Groups in Clinical Presentation and Hemodynamic Characteristics

oyamoya disease(MMD is defined as the development of collateral anastomosis pathways associated with bilateral chronic progressive stenosis of the carotid fork. We have reviewed the types of presentation angiograms and single photon emission computed tomographs(SPECT. Ninety-nine patients were divided into three groups (aged below 5 years between 5 and 15 years and 16 or over to investigate whether there were differences in clinical presentation and hemodynamic characteristics between the age groups. Mean age of the 99 patients was 13.6 years and the mean duration of symptoms was 26.2 months. In the 17 children aged less than five the duration of symptoms was shorter(4.8 months than in older patients(p<0.05. The former presented mostly with cerebral infarction(59% with a widespread cerebral perfusion defect(50%. Among 56 children who were 5 to 15 years old 42 (75% presented with transient ischemic attacks and 10(18% with cerebral infarction； the latter was less frequent in this age group than in other age groups. Twelve(46% out of 26 adult patients had hemorrhage at the initial diagnosis which was the most frequent presentation in this age group. Stenosis of the posterior cerebral artery was detected in 27% of adult MMD patients while it was detected in 39% of children. Moreover no case showed widespread perfusion defects in the adult group. The results suggest that the patterns of presentation and the hemodynamic features differ according to the age at which initial major symptoms occur. Children aged less than five suffer rapid progression of the disease and severe cerebral pefusion defect and should therefore undergo early surgery. The less frequent involvement of MMD in the posterior circulation and better-preserved cerebral perfusion are characteristic findings of the disease in adults and this seems to account for its delayed onset.