B – 32 The Relationship between Post-Concussion Symptom Domains and Loss of Consciousness/Post-Traumatic Amnesia

Abstract Objective This study examined differences in post-concussion symptom domains based on self-reported loss of consciousness (LOC) and post-traumatic amnesia (PTA) at time of injury. Method Undergraduate participants (N=384; Mage=18.9, SD=1.5; 85.2% Female; 76.0% White, 2.6% Hispanic; 28.9% prior concussion) completed a health history form and the Post-Concussion Symptom Scale (PCSS), a 22-item self-report measure with support for a four-factor structure (i.e., cognitive, physical, sleep-arousal, affective). PCSS scores were compared between controls (no concussion history; n=273) and participants with self-reported prior concussion who did (n=60) or did not report (n=51) a past LOC/PTA episode, with Glass’s delta (∆) estimating effect size. In the concussion groups, 67.6% of participants were >1-year post-injury. Time-since-injury and total number of lifetime concussions were also compared by LOC/PTA status. Results Physical, cognitive, sleep-arousal, and total PCSS symptom scores were significantly greater in the LOC/PTA group compared to controls (ps<.001, ∆ range=.43 to .50) and no LOC/PTA group (ps<.01, ∆ range=.44 to .51). There were no significant group differences in time since injury (p=.30), although the LOC/PTA group reported more prior concussions (M=2.3, SD=1.7) than the no LOC/PTA group (M=1.7, SD=1.1; p=.008, ∆=.39). Conclusion Participants with past LOC/PTA had significantly greater symptom scores than participants with no concussion history or concussion without LOC/PTA. Affective symptoms were similar across groups, highlighting their non-specificity to concussion. Persistent symptomatology may be related to the cumulative effects of multiple concussions in the LOC/PTA group. Clinical signs of injury may relate to symptom severity, but further research in acute and treatment-seeking populations is warranted.