The prediction of contralateral progression in children and adolescents with unilateral moyamoya disease.

BACKGROUND AND
PURPOSE: To evaluate the factors predictive of contralateral progression in children and adolescents with unilateral moyamoya disease (MMD), the authors retrospectively analyzed clinicoradiological findings.
METHODS: The records of 394 consecutive patients with MMD aged 0 to 17 years were reviewed. Unilateral MMD was defined based on the typical angiographic findings of MMD in 1 hemisphere and no abnormality in the contralateral internal carotid artery and the middle cerebral artery. Of the 394 patients with MMD, 45 (11.4%) had unilateral MMD and the prevalence increased with age. Untreated contralateral hemispheres were followed by serial MR angiography. Follow-up angiography was performed if contralateral progression, defined as any noticeable change in the contralateral internal carotid artery and/or middle cerebral artery, was suggested by MR angiography.
RESULTS: Eight of the 45 (17.8%) had angiographically documented progression over a mean follow-up of 53.4 months. Mean time to contralateral progression was 27 months (range, 21 to 37 months). An age at diagnosis of <9 years was found to be the only independent predictor of contralateral progression (P=0.025), which persisted despite adjustment for sex and ipsilateral Suzuki stage (hazard ratio, 8.26; 95% CI, 1.01 to 67.94). Other factors, including abnormalities in the contralateral anterior cerebral artery, were not found to be predictive of progression to bilateral MMD.
CONCLUSIONS: The incidence of contralateral progression in our cohort of children and adolescents with unilateral MMD appears to be lower than those previously reported. Furthermore, contralateral progression tended to occur in children aged <9 years within 3 years of initial diagnosis (32%).