Neurofibromatosis type 1 with comorbid optic pathway glioma does not confer additional cognitive sequelae.

Children with neurofibromatosis type 1 (NF1) are at risk for cognitive impairments. Optic pathway gliomas (OPGs) commonly occur in children with NF1, though whether OPG exacerbates cognitive vulnerabilities beyond the NF1 genotype remains unclear. This study compared cognition among children with NF1 and OPG (NF1 + OPG), children with NF1 without OPG (NF1-only), and children with central nervous system (CNS) tumors of the visual system without NF1 (CNS-V), to evaluate whether OPG confers additional cognitive risk beyond NF1. This retrospective clinical cohort study included 98 pediatric patients referred for a clinical neuropsychological evaluation: 69 NF1-only, 21 NF1 + OPG, and 8 CNS-V tumor. Intellectual functioning, verbal reasoning, visuospatial reasoning, working memory, and processing speed were examined. Group differences were analyzed using one-way analyses of variance; chi-square tests assessed impairment rates. Children with NF1 with and without OPG did not differ significantly across cognitive domains. Both NF1 groups (NF1-only and NF1 + OPG) demonstrated weaker verbal and visuospatial reasoning abilities compared to the CNS-V group. In contrast, children with CNS-V tumors performed within the average range across domains with significantly stronger intellectual performance than both NF1 groups. OPG does not appear to exacerbate cognitive vulnerability in children with NF1. Cognitive weaknesses in NF1 likely reflect the underlying genotype rather than added tumor burden. Comparatively, children with non-NF1 visual system tumors demonstrated average performance. These findings underscore the importance of routine neuropsychological monitoring in children with NF1 regardless of tumor status and highlight the need for prospective, adequately powered studies to further disentangle genotype- and tumor-related effects.