Predictors of cognitive development in children with neurofibromatosis type 1 and plexiform neurofibromas

Aim: To describe the cognitive development of children with neurofibromatosis type 1 (NF1) and plexiform neurofibromas, and identify predictors of cognitive development. Method: Participants included 88 children with NF1 and plexiform neurofibromas (50 males, 38 females, aged 6–18y, mean=12y, SD=3y 7mo) on a natural history study at the National Cancer Institute. Neuropsychological assessments (e.g. IQ, academic achievement, attention, and executive functioning) were administered three times over 6 years. Results: Relative to normative peers, the total sample of children with NF1 and plexiform neurofibromas demonstrated significantly lower scores in most cognitive domains and decreasing z-scores over time in math, writing, inhibitory control, and working memory. Children who had parents with (vs without) NF1 were more likely to experience decreased z-scores in performance IQ, reading, writing, attention, and working memory. Higher (vs lower) parental education was related to higher levels of IQ, math, reading, and cognitive flexibility and a slower decrease in math z-scores. Children’s sex and the number of NF1 disease-related complications were not related to most cognitive outcomes. Interpretation: Children with NF1 and plexiform neurofibromas are at high risk for cognitive difficulties and declining z-scores in various domains of cognitive functioning over time. The findings highlight the need for a better understanding of the within-group differences in these children and their need for individualized educational plans. What this paper adds: Math, writing, inhibitory control, and working memory scores decreased over time. The proportion of children with clinically significant cognitive deficits increased over time. Parental neurofibromatosis type 1 and low education were related to greater cognitive difficulties in children.