0635 Acute Night-to-Night Sleep Onset Latency Variation within Concussed College Students: A Pilot Study

Abstract

Introduction: Greater sleep-wake cycle dysfunction post-concussion might result from night-to-night variation among various sleep outcomes. Recent evidence supports that concussed individuals experience acute sleep variation in their total sleep time and sleep fragmentation, which is cause for concern as it may be associated with prolonged symptom duration. The objective of this study was to determine whether night-to-night sleep pattern variation differs between concussed individuals and matched controls one and two weeks post-injury. Method(s): Twenty college students were physician-diagnosed with a concussion. Thirteen concussed individuals with symptom durations >=14 days (23.5+/-8.4days) were included in this analysis in order to examine sleep across the initial two weeks post-injury compared to non-concussed controls matched on age, sex, physical activity, and sleep quality. A wrist-worn Actigraph device was provided during initial evaluation (within 72 hours post-injury for concussed) and worn continuously until symptom resolution (duration matched for non-concussed). Intraindividual coefficient of variations (CV) were calculated for each actigraphy sleep outcome (sleep onset latency (SOL), normalized wake after sleep onset (WASOnorm), total sleep time (TST), sleep efficiency, and number of awakenings) for weeks 1 and 2 post-injury. Separate 2(group) x 2(time-points) mixed-model ANOVAs were conducted to compare CV of sleep outcomes across week 1 and week 2 post-injury between concussed and non-concussed individuals. Paired samples t-tests were conducted to examine CV within groups between week 1 and week 2 post-injury (alpha=0.05). Result(s): Across week 1 post-injury, concussed individuals experienced greater intraindividual variability in SOL (F1,24=10.84, p=0.003) compared to non-concussed individuals. Concussed individuals experienced greater intraindividual variability in SOL across week 1 compared to week 2 post-injury (t(12)=3.35, p=0.006). Intraindividual variability differences did not exist in other sleep outcomes across weeks 1 and 2. Conclusion(s): Greater night-to-night variation existed in SOL between concussed and non-concussed individuals during the first week post-injury and among concussed individuals between weeks 1 and 2 post-injury. Greater night-to-night variability during the first week post-injury may be a result of the concussion itself and may have clinical implications for the acute management of sleep post-concussion.