Distinct Clinical and Radiographic Phenotypes in Pediatric Moyamoya Patients

Abstract Objectives Compare the clinical and radiographic features of childhood moyamoya disease (MMD) and syndrome (MMS) in order to identify predictors of ischemic event recurrence. Methods We retrospectively reviewed a pediatric moyamoya cohort followed prospectively between 2003 and 2019. Clinical and radiographic characteristics at diagnosis and follow-up were abstracted. Comparisons between MMD and MMS as well as between MMD and two MMS subgroups (neurofibromatosis [MMS-NF1] and sickle cell disease [MMS-SCD]) were performed. Results One hundred and eleven patients were identified (49 MMD; 62 MMS; 23 MMS-NF1; 21 MMS-SCD). MMD patients presented commonly with transient ischemic attacks (TIA) (35 % MMD vs 13% MMS-NF1 vs 9.5% MMS-SCD; p=0.047). Symptomatic stroke presentation (MMD 37% vs MMS-NF1 4% vs 33%; p=0.0147) and bilateral disease at diagnosis (MMD 73% vs MMS-NF1 22 % vs MMS-SCD 67%; p=0.0002) were uncommon in MMS-NF1. TIA recurrence was common in MMD (HR 2.86; p=0.001). The ivy sign was absent on neuroimaging in a majority of MMS-SCD patients (MMD 67% vs MMS-NF1 52% vs MMS-SCD 9.5%; p=0.0002). Predictors of poor motor outcome included early age at diagnosis (≤ 3 years) (OR 8.45; p=0.0014), symptomatic stroke presentation (OR 6.6; p.0.019) and advanced Suzuki stage (OR 3.59; p=0.019). Interpretation Moyamoya arteriopathies exhibit different phenotypes based on underlying etiologies. Frequent TIAs is a common phenotype of MMD and symptomatic stroke presentation a common feature of MMD and MMS-SCD, while unilateral disease and low infarct burden is common in MMS-NF1. In addition, absence of ivy sign is a common phenotype in MMS-SCD.