Frequent early cognitive impairment in both pediatric MS and MOGAD.

BACKGROUND: Studies on early cognitive impairment (CI) in pediatric multiple sclerosis (MS) are heterogeneous and data on pediatric myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are scarce. OBJECTIVES: To evaluate early cognitive dysfunction in both diseases and delineate disease-specific neurocognitive profiles. METHODS: A cross-sectional study of children with MS and MOGAD assessed neurocognition within 2 years after disease onset using a comprehensive test battery. Test results were converted to Z-scores. CI was defined as Z-scores below -1.5 in ⩾2 domains. Children were compared by CI status and domain deficits quantified with composite Z-scores. RESULTS: Sixty-seven participants were analyzed (MS n = 36, MOGAD n = 31). Despite normal full-scale intelligence quotient, 47% of MS children and 43% of MOGAD children (acute disseminated encephalomyelitis excluded) met criteria for CI. Domain-specific impairments were prominent in complex attention, with significantly reduced composite Z-scores (MS: -1.24, p < 0.001; MOGAD: -1.12, p = 0.019). MS children additionally showed lower scores on tasks of visuospatial processing and visual memory. Only fatigue was significantly associated with the presence of CI (PedsQL fatigue Z-score: -2.61 vs -0.75, p = 0.005). CONCLUSION: In both pediatric MS and MOGAD, early CI is prevalent with difficulties in complex attention. Visuospatial cognition appears to be an additional vulnerable area for children with MS.