Sleep Disturbances and Cognition, Behavior, and Brain Structure in Children With mTBI.

Importance: Sleep disturbances are increasingly recognized as a modifiable factor associated with poor outcomes after mild traumatic brain injury (mTBI) in adults, yet their prevalence, mechanisms, and clinical impact in children remain largely unknown. Identifying whether sleep problems contribute to behavioral, cognitive, and neurobiological outcomes after pediatric mTBI could inform targeted interventions. Objective: To determine the prevalence of sleep disturbances after pediatric mTBI and to assess associations with behavioral symptoms, cognition, and brain structure. Design, Setting, and Participants: This multisite, population-based cohort study is a secondary analysis of data collected between September 2016 and January 2020 as part of the Adolescent Brain Cognitive Development Study 5.0 release. Participants were children who sustained an mTBI between baseline (age 9-10 years) and 2-year follow-up (age 11-12 years). Children with mTBI were propensity score-matched on the basis of age, sex, study site, self-reported race, and total family income to typically developing children (TDC) and orthopedic injury (OI) controls. Data were analyzed September 2024 to June 2025. Exposure: mTBI between baseline and follow-up. Main Outcomes and Measures: The primary outcomes were parent-reported sleep disturbances (categorized as new onset, chronic, improving, or none), behavioral problems, and cognitive performance. Magnetic resonance imaging was used to examine cortical thickness, cortical volume, and white matter microstructure. Analyses used linear regressions and linear mixed models, controlling for baseline when appropriate. Results: Of 573 children, there were 191 children with mTBI (mean [SD] age, 12.03 [0.6] years; 112 [58.6%] male). Children with mTBI were more likely than controls to develop new clinical sleep disturbances (29 children with mTBI [15.2%] vs 22 of 191 children [11.5%] in the TDC group and 19 of 191 children [9.9%] in the OI group) and had higher rates of chronic sleep disturbances (41 children [21.5%] with mTBI vs 25 children [13.1%] in the TDC group and 25 children [13.1%] in the OI group). Total sleep disturbance scores were significantly elevated for children with mTBI compared with the TDC group (β, -0.27; 95% CI, -0.45 to -0.10), but not the OI group (β, -0.12; 95% CI, -0.29 to 0.05). Higher behavioral symptoms were found compared with the TDC group (β, -0.30; 95% CI, -0.45 to -0.16) and were associated with sleep problems, especially newly emerging disturbances, after mTBI. Children in the OI group exhibited greater cortical thickness (β, 0.18; 95% CI, 0.06 to 0.30) and volume (β, 0.06; 95% CI, 0.01 to 0.11) than children with mTBI, with both being positively associated with sleep disturbances in children with mTBI. No group differences were found in cognition or white matter microstructure or associations with sleep. Conclusions and Relevance: In this cohort study, sleep disturbances were more common among children with mTBI than among TDC. In particular, newly developing sleep problems appeared to be a potential key pathway to behavioral problems and a promising interventional target. Cognitive and structural brain outcomes were not significantly associated with sleep disturbances in this cohort.