High Baseline Postconcussion Symptom Scores and Concussion Outcomes in Athletes

Context: Some healthy athletes report high levels of baseline concussion symptoms, which may be attributable to several factors (eg, illness, personality, somaticizing). However, the role of baseline symptoms in outcomes after sport-related concussion (SRC) has not been empirically examined. Objective: To determine if athletes with high symptom scores at baseline performed worse than athletes without baseline symptoms on neurocognitive testing after SRC. Design: Cohort study. Setting: High school and collegiate athletic programs. Patients or Other Participants: A total of 670 high school and collegiate athletes participated in the study. Participants were divided into groups with either no baseline symptoms (Postconcussion Symptom Scale [PCSS] score = 0, n = 247) or a high level of baseline symptoms (PCSS score > 18 [top 10% of sample], n = 68). Main Outcome Measure(s): Participants were evaluated at baseline and 2 to 7 days after SRC with the Immediate Postconcussion Assessment and Cognitive Test and PCSS. Outcome measures were Immediate Post-concussion Assessment and Cognitive Test composite scores (verbal memory, visual memory, visual motor processing speed, and reaction time) and total symptom score on the PCSS. The groups were compared using repeated-measures analyses of variance with Bonferroni correction to assess interactions between group and time for symptoms and neurocognitive impairment. Results: The no-symptoms group represented 38% of the original sample, whereas the high-symptoms group represented 11% of the sample. The high-symptoms group experienced a larger decline from preinjury to postinjury than the no-symptoms group in verbal (P = .03) and visual memory (P = .05). However, total concussion-symptom scores increased from preinjury to postinjury for the no-symptoms group (P = .001) but remained stable for the high-symptoms group. Conclusions: Reported baseline symptoms may help identify athletes at risk for worse outcomes after SRC. Clinicians should examine baseline symptom levels to better identify patients for earlier referral and treatment for their injury. Additional investigation of baseline symptoms is warranted to help delineate the type and severity of premorbid symptoms.