Accurate, objective methods for tracking recovery after concussion are essential, yet reliable predictors of adolescent outcomes remain limited. Heart rate variability (HRV), reflecting the coordination between central and peripheral nervous systems, may reveal hidden impairments and serve as an early indicator of symptom progression. This study explored the connection between HRV and recovery trajectories in adolescents and evaluated its potential as a prognostic tool. Fifty-five adolescents (ages 12–17) presenting with concussion at a local sports medicine clinic underwent an initial subacute assessment within 15 days of injury, followed by a post-acute evaluation. Data collected included self-reported clinical and depressive symptoms, neurobehavioral assessments, and cognitive testing. Short-term HRV measurements were obtained via photoplethysmography during both rest and stress conditions. Analyses showed significant links between HRV and clinical, neurobehavioral, and cognitive outcomes at the subacute stage. Critically, subacute HRV measures were able to predict reduced neurobehavioral and cognitive performance at follow-up. These findings indicate that HRV assessed shortly after concussion could function as a predictive biomarker, identifying underlying neurological dysfunction and signaling potential long-term cognitive challenges.
