Disrupted maturation of white matter microstructure after concussion contributes to internalizing behavior problems in female children

1.Some children that experience a concussion exhibit long-lasting emotional and behavioral problems post-injury, with greater rates of persistent problems in females. Establishing the contribution of (1) pre-existing behavioral problems and (2) disrupted maturation of the brains vulnerable white matter, to long-lasting behavioral problems has been a challenge due to a lack of pre-injury behavioral and imaging data. From the Adolescent Brain Cognitive Development Cohort, this study examined 204 11-12-year-old children who experienced a concussion after baseline data collection at age 9-10-years-old. Internalizing and externalizing behavioral problems were assessed with the Child Behavior Checklist. In 99 of these children with MRI data available, white matter microstructure was characterized in deep and superficial white matter by neurite density from restriction spectrum image modeling of diffusion MRI. Linear regressions modeled 1) post-concussion behavior symptoms controlling for pre-injury behavior, 2) the impact of concussion on white matter maturation, and 3) the contribution of deviations in white matter maturation to post-concussion behavior symptoms. When controlling for preinjury scores, post-injury internalizing and externalizing scores were higher in female but not male children with concussion compared to children with no concussion. Group comparisons of change in neurite density over two years reflecting white matter maturation demonstrated an age-dependent effect whereby younger female children had less change in neurite density over time than younger children with no concussion. In female children with concussion, less change in superficial white matter neurite density over time was associated with more internalizing behavior problems. These results suggest that in female children, concussions are associated with behavior problems beyond those that exist pre-injury, and injury to the brains vulnerable white matter may be a biological substrate underlying persistent internalizing behaviors.