Abstract TP408: Risk Factors for Clinical and Radiographic Progression in Pediatric Moyamoya

Objective: To compare clinical and radiographic evolution of moyamoya disease (MMD) and moyamoya syndrome (MMS). Method: We conducted a retrospective review of a prospectively enrolled cohort of children with moyamoya followed from 2003 to 2018. Patients with a final diagnosis of PHACE syndrome and transient cerebral arteriopathy were excluded. Demographic, clinical and radiographic (MRI) characteristics at diagnosis were obtained. Evidence of clinical evolution (stroke, TIA) or radiographic progression were assessed on subsequent clinical visits and neuroimaging, respectively. We compared the frequency and time to clinical and radiographic progression prior to revascularization surgery between MMD and MMS (including specific etiologies, namely neurofibromatosis [NF1] and sickle cell disease [SCD]). Comparisons were conducted using independent t or chi-square tests, as appropriate. Results: Ninety-three patients were identified, of whom 37 had MMD and 56 had MMS (20 NF1, 20 SCD and 16 others etiologies). The median age at presentation was 8.31 years (IQR 5.03-10.87) and the median follow up time was 5 years ( IQR 2-8). MMD were at greater risk of a recurrent ischemic event (52% MMD vs 42% MMS, p=0.049), but no difference was noted between MMD, NF1 and SCD. The risk of ischemic event recurrence was significantly higher among patients who presented with TIA at diagnosis (79.26% vs 21%, p <0.0001), an advanced Suzuki stage (59% with Suzuki 3-6 vs 28% Suzuki with 1-3, p= 0.009) and bilateral moyamoya (47% vs 21.95% with unilateral, p=0.012). No difference was noted between groups regarding the median time to radiographic progression. Radiographic progression was more likely among younger children (50% if less 10 years vs 21% if more than 10 years, p= 0.0085) and children presenting with TIA (53% vs 34%, p=0.038). Conclusions: TIA at presentation, advance Suzuki stage, and bilateral disease conferred greater ischemic risk among children with moyamoya. Vasculopathy progression was more likely among young patients and those with TIA at presentation.