To characterize neuropsychological outcomes in pediatric patients with moyamoya arteriopathy (MMA).

Moyamoya arteriopathy is a progressive occlusive arteriopathy due to either idiopathic causes (moyamoya disease; MMD) or associated with systemic diseases such as Down syndrome or neurofibromatosis type 1 (moyamoya syndrome; MMS). MMA causes neuropsychological impairment, likely due to stroke and cerebral hypoperfusion. Prior studies have examined intellectual impairment in MMD; few have explored other cognitive domains or included patients with MMS.

We conducted a retrospective chart review and identified patients <18 years old with MMA seen at Johns Hopkins/Kennedy Krieger Institute from 2002-2021 who completed neuropsychological testing in ≥2 cognitive domains. Impairment was defined as scores <2^nd percentile on validated, age-appropriate tests/subtests. Clinical and radiographic data were compiled. Associations between clinical and radiographic characteristics and impairment in each domain were assessed using Fisher’s exact test.

We identified 86 patients; 11 had appropriate testing available. This sample included 3 patients with MMD and 8 with MMS (4 sickle cell, 3 neurofibromatosis, 1 hemophilia). Median age at testing was 7.3 years (IQR 5.5-8.4). Eight (73%) patients had a history of stroke; 6 (55%) had bilateral arteriopathy. Six patients (55%) had impairment in ≥2 cognitive domains. Of 10 domains examined, memory was most commonly impaired (56%), followed by attention and executive functioning (50%), visuospatial functioning (50%), and math ability (50%). Patients with bilateral (versus unilateral) arteriopathy were more likely to have visuospatial (p=0.048) and language (p=0.015) impairment. In our sample, no significant differences emerged between children with MMD versus MMS.

Significant neuropsychological impairment across domains is evident in MMA. Bilateral arteriopathy is associated with impairment in visuospatial functioning and language. Future prospective studies are needed to provide longitudinal data on neuropsychological functioning in children with MMA and to assess the impact of surgical revascularization on neuropsychological outcomes.