Acute Cognitive Symptom Cluster Predicts Return-toLearn Duration Following a Sport-Related Concussion

OBJECTIVE Adolescents sustaining sport-related concussion often experience difficulties with the return-to-learn (RTL) process. Whereas the initial symptom burden has predicted prolonged RTL, no studies have established a relationship between acute cognitive symptoms and RTL duration. The authors sought to evaluate the relationship between initial cognitive symptoms and RTL duration. METHODS A retrospective single-institution cohort study of adolescent athletes aged 12–23 years who were evaluated within 5 days of a diagnosed sport-related concussion between November 2017 and October 2020 was conducted. Athletes missing cognitive symptom ratings and RTL data were excluded. The primary exposure variable was the Cognitive Symptom Ratio (CSR), defined as total cognitive symptom cluster score divided by total Post-Concussion Symptom Scale (PCSS) score from the initial clinic visit. Primary and secondary outcomes were time to RTL and total length of care, respectively. Multivariable Cox proportional hazards modeling was used to assess the effect of CSR on RTL duration. RESULTS Of 653 athletes evaluated within 5 days of injury, 346 patients were included in the final cohort. Athletes reported a median initial PCSS score of 21 (interquartile range [IQR] 6–37) and a median cognitive symptom score of 4 (IQR 0–9). Most patients endorsed some degree of difficulty concentrating (n = 212, 61.3%). The median CSR was 0.18 (IQR 0.00–0.27). On multivariable regression analysis, a higher CSR was associated with prolonged RTL duration (HR 0.30, 95% CI 0.13–0.69, p = 0.004). When initial PCSS score was added to the model, the previously significant association between CSR and RTL was no longer significant (HR 0.67, 95% CI 0.29–1.59, p = 0.367). When dichotomized based on frequency distribution, a higher proportion of patients with low CSR achieved RTL by 7 days postinjury (82.2% vs 69.9%, p = 0.007), a difference not seen at 14 days (92.2% vs 87.3%, p = 0.133). CONCLUSIONS An acute ratio of cognitive symptoms may predict patients at increased risk for prolonged RTL and those with normal PCSS scores who may experience difficulties once resuming school activities.