Less Than Half of Patients Recover Within 2 Weeks of Injury After a Sports-Related Mild Traumatic Brain Injury: A 2-Year Prospective Study.

OBJECTIVE: To describe clinical recovery time and factors that might impact on recovery after a sports-related mild traumatic brain injury (SR-mTBI; concussion). DESIGN: Prospective cohort study (level IV evidence). SETTING: New Zealand Sports Concussion Clinic. PARTICIPANTS: Eight hundred twenty-two patients presenting within 14 days of a SR-mTBI/concussion over a 2-year period. MAIN OUTCOME MEASURES: Clinical recovery measured as number of days after injury. INTERVENTIONS METHODS: Participants were assessed and managed using a standardized protocol consisting of relative rest followed by controlled cognitive and physical loading. A reassessment was performed 14 days after injury with initiation of an active rehabilitation program consisting of a subsymptom threshold exercise program ± cervicovestibular rehabilitation (if required) for participants who remained symptomatic. Participants were then assessed every 2 weeks until clinical recovery. RESULTS: A total of 594 participants were eligible for analysis (mean age 20.2 ± 8.7 years, 77% males) and were grouped into 3 age cohorts: children (≤12 years), adolescents (13-18 years), and adults (≥19 years). Forty-five percent of participants showed clinical recovery within 14 days of injury, 77% by 4 weeks after injury, and 96% by 8 weeks after injury. There was no significant difference in recovery time between age groups. Prolonged recovery was more common in females (P = 0.001), participants with "concussion modifiers" (P = 0.001), and with increased time between injury and the initial appointment (P = 0.003). CONCLUSIONS: This study challenges current perceptions that most people with a SR-mTBI (concussion) recover within 10 to 14 days and that age is a determinant of recovery rate. Active rehabilitation results in high recovery rates after SR-mTBI.

Predicting Sport-related mTBI Symptom Resolution Trajectory Using Initial Clinical Assessment Findings: A Retrospective Cohort Study.

OBJECTIVES: To identify which aspects of initial clinical assessment for sport-related mild traumatic brain injury (SR-mTBI) predict whether an athlete achieves symptom resolution within 14 days of the injury. RESEARCH DESIGN: Retrospective cohort study using prospectively collected data. METHODS: Clinical assessment data were collected from 568 patients diagnosed with SR-mTBI at a single medical clinic between February 2017 and December 2018. Demographic data, medical history, SCAT-5 testing, and physician notes were included in the data set. Data were processed and analysed to identify a shortlist of predictor variables to develop a logistic regression model to discriminate between SR-mTBI symptom resolution that occurred in ≤ 14-days or > 14-days. The data were randomly divided into model development and validation subsamples. The top 15 models were analysed to determine the predictor variables to be included in the final logistic regression model. The final model was then applied to the validation subsample. RESULTS: Half of the athlete participants in this study experienced > 14-day symptom resolution. The final logistic regression model included sex, symptom reporting at initial assessment and presentation with a physiological predominant symptom cluster. The model accounted for 0.90 and 0.85 of the area under the curve and predicted recovery trajectory with 81% and 76% accuracy for the training and validation subsamples, respectively. CONCLUSIONS: Being female, reporting a higher Positive Symptom Total at initial assessment, and being less likely to have a physiological predominant symptom cluster at initial assessment predicted > 14 versus ≤ 14-day SR-mTBI symptom resolution with a high level of accuracy.