Presentation and Progression of Posterior Cerebral Artery Stenosis in Children with Moyamoya Arteriopathy.

OBJECTIVE: To assess the prevalence of posterior cerebral artery (PCA) stenosis, its risk factors, and disease progression in children with moyamoya arteriopathy. STUDY DESIGN: We retrospectively reviewed all patients <21 years old with moyamoya who underwent surgical revascularization at a single institution between December 2015-2022. Patients were assessed for the presence of PCA stenosis and timing of onset or progression. Clinical and radiographic features were compared between children with and without PCA involvement. RESULTS: Among159 children with moyamoya, 36 (23%) had PCA stenosis, of whom 18 (50%) presented with PCA stenosis at time of moyamoya diagnosis. Among children who developed PCA stenosis during ongoing monitoring (n=18), the median time to onset of PCA involvement was 43 weeks. No significant differences in age at moyamoya diagnosis, sex, or race were identified between groups. Children with PCA stenosis were significantly more likely to have bilateral disease requiring revascularization (p=0.02). Children with moyamoya and cardiac anomalies had 4-fold higher odds of PCA stenosis (p=0.006). CONCLUSIONS: PCA stenosis occurs in approximately one-quarter of children with moyamoya, with half presenting at diagnosis. The association of PCA stenosis and cardiac anomalies in children with moyamoya may warrant genetic evaluations in affected children.