Symptom recovery and the relationship between post-injury symptom scores and neurocognitive performance in athletes with sport-related concussion

Introduction A multi-domain approach to concussion assessment has been recommended that includes self-reported symptom severity in addition to neurocognitive tests and measures of postural stability. The relationship between subjective self-reported symptoms and objective measures of cognitive function in the post-injury state is not well understood. The aims of the study were to determine symptom severity throughout the post-injury continuum of care and the association between symptom severity and performance on measures of neurocognitive function. Methods An observational cohort study was conducted on 1257 high school and collegiate athletes (67% male and 33% female) who had sustained a concussion. Student-athletes were included in the study if they had a healthy baseline assessment and at least one follow-up injury assessment utilizing the Cleveland Clinic Concussion Application (C3 App). Symptom severity was assessed during the acute (0–7 days post-injury), subacute (8–20 days post-injury), and post-concussive (≥21 days post-injury) phases. Neurocognitive performance was assessed using the following measures: Simple Reaction Time (SRT), Choice Reaction Time (CRT), Processing Speed Test (PST), Trail Making Test A (TMT-A), and Trail Making Test B (TMT-B). To determine the relationship between symptom severity and neurocognitive test performance, athletes were stratified into two groups for comparison: symptom score ≤7 or >7, utilizing the 27-item graded symptom checklist within the C3 App. Neurocognitive performance was analyzed with separate linear mixed effect models for each module to compare within-phase differences. Significance for each module at each phase was tested at P < .05 and adjusted for multiple comparisons. Results Median symptom severity during the acute post-injury phase was 10 declining to 2 during the subacute and post-concussive phases. Performance on each of the C3 App modules (SRT, CRT, PST, Trails A, and Trails B) were significantly better in athletes reporting a symptom score of ≤7 compared to those reporting a symptom score >7 at each of the post-injury phases (P < 0.05 on all comparisons). Conclusions Symptomatic athletes performed worse on all measures of neurocognitive function, regardless of time from injury. While symptoms alone should not be used to determine recovery, our data indicate that symptom severity may aide in deciding when to initiate post-injury neurocognitive testing to determine readiness for treatment progression.