Brain Network Functional Connectivity in Children With a Concussion

Pediatric concussion can disrupt functional brain network connectivity, but prospective longitudinal research is needed to clarify recovery and identify moderators of change. This study investigated network functional connectivity (FC) up to 6 months after pediatric concussion. This prospective longitudinal concurrent cohort observational study consecutively recruited children (aged 8 to 17 years) at 5 Canadian pediatric hospital emergency departments within 48 hours of sustaining a concussion or mild orthopaedic injury (OI). Children completed 3T MRI scanning postacutely (2 to 33 days) and at either 3 or 6 months after injury (randomly assigned at the postacute visit). Reliable change between retrospective preinjury (based on parent report) and 1-month postinjury symptom ratings based on parent and child report was used to classify concussion with or without persisting symptoms. Within-network and between-network FC was computed for 8 brain networks from resting-state fMRI scans and analyzed using linear mixed-effects models, with multiple comparison correction. Groups (385 with concussion/198 with OI; 59% male; 69% White; age 12.42 ± 2.29 years) did not differ in within-network FC. Relative to OI, connectivity between the visual and ventral attention networks was lower after concussion, d (95% CI) = -0.46 (-0.79 to -0.14), across time. Connectivity between the visual and default mode networks was lower at 6 months after concussion, -0.60 (-0.92 to -0.27). At 3 months after concussion, connectivity between the frontoparietal and ventral attention networks was lower in younger children, -0.98 (-1.58 to -0.37), but higher in older children, 0.81 (0.20 to 1.42). For symptom groups based on parent report, connectivity between the dorsal and ventral attention networks was higher in female children at 3 months after concussion without persisting symptoms relative to concussion with persisting symptoms, 1.25 (2.05 to 0.46), and OI, 0.87 (0.25 to 1.49). Time after injury, age at injury, biological sex, and persistent symptom status are important moderators of FC after pediatric concussion for children seen in emergency department settings. Postacute FC may not enhance clinical diagnosis. Although within-network connectivity is preserved, between-network connectivity differences emerge after most children clinically recover and persist up to 6 months after pediatric concussion, providing a potential objective biomarker for lasting changes in brain function.