Participants and Study Design

We conducted a cross-sectional study of youth athletes aged 13 to 17 years who had recently sustained a concussion or were uninjured control participants. Concussion participants were seen for care at the institution's Sports Medicine Center and diagnosed with a concussion within 14 days of their injury. All concussions were diagnosed by Board-certified sports medicine physicians, consistent with the definition provided by the most recent international consensus statement on concussion in sport at the time of data collection.¹ Participants completed the Post-Concussion Symptom Inventory (PCSI), a validated measure of concussion-related symptoms,¹³ at the time of assessment. Individuals with concussion reported higher PCSI scores, indicating an elevated level of concussion-related symptoms, than healthy control individuals. Recruits in the concussion group were excluded if they received a diagnosis for any injury other than a concussion or related sequelae (eg, neck strain) at the time of assessment. Control recruits were tested during routine preparticipation sport physical evaluations. All control group participants received clearance to engage in sport without restriction from a physician at the time of assessment, thus confirming their healthy status. No patients in the concussion group were among those tested during the preparticipation physical evaluations. Exclusion criteria for both groups were a history of epilepsy or seizure, preexisting neurologic or psychiatric disorder, or a diagnosed concussion within 6 months of the assessment (other than the injury for which the concussion group was being seen). Before the study, the local institutional review board approved the protocol, and all participants and their parents or legal guardians provided written informed assent and consent, respectively, to be involved in the study.