Baseline Neurocognitive Test Results In Non-concussed Athletes: Does Sleep Matter?

Abstract

Objectives:When managing sport-related concussions (SRC), sports medicine physicians utilize serial neurocognitive assessments and self-reported symptom inventories when evaluating athlete recovery and safety for returning to play (RTP). Since post-concussive RTP goals include symptom resolution and return to neurocognitive baseline, clinical decisions rest on an understanding of modifiers of baseline performance. Several studies have reported the influence of age, gender and sport on baseline neurocognitive performance, but few have assessed the potential effect of sleep. We hypothesized that: 1) athletes receiving less sleep prior to baseline testing would perform worse on neurocognitive metrics; and 2) decreased sleep would have no association with the quantity of reported symptoms.Methods:We retrospectively reviewed 3,704 non-concussed athletes, 2,385 male, 3,321 high school and 383 college-aged, with baseline symptom and neurocognitive scores on Immediate Post-concussion Assessment and Cognitive Testing (ImPACT). Subjects were stratified into three groups based on self-reported sleep duration the night prior to testing; 1) short < 7 hrs, 2) intermediate 7−9 hrs; and 3) long ≥ 9 hrs). Multivariate analysis assessed the influence of categorical sleep duration on the baseline number of reported symptoms and ImPACT performance, with alpha level of 0.05.Results:When controlling for age, gender and sport as covariates, the multivariate analysis of covariances showed a significant association between shorter sleep duration and poorer verbal memory scores (p=0.019), visual memory scores (p=0.035), and reaction time scores (p=0.044), but not for visual-motor scores. Significance was found between shorter sleep duration and increased number of reported symptoms (P < 0.0001). Subsequent pairwise comparisons revealed these associations to be most significant when specifically comparing the short and intermediate sleep groups.Conclusion:Our results indicate that athletes sleeping less than 7 hours prior to testing perform worse on 3 out of 4 neurocognitive ImPACT scores and endorse more symptoms. Because concussion management and RTP decisions hinge on the comparison to a reliable baseline evaluation, sports medicine physicians should strongly consider amount of sleep prior to neurocognitive testing in the assessment of athletes’ recovery.

The Effect of Preinjury Sleep Difficulties on Neurocognitive Impairment and Symptoms After Sport-Related Concussion

“…This finding extends previous research that reported a similar relationship between reduced sleep duration, as opposed to sleep difficulties as measured in the current study, and concussionrelated symptoms at baseline. 24,27 These findings reflect the previously reported bidirectional relationships between sleep and subclinical emotional complaints as well as diagnosed mental health conditions. 3,30 Somatic and cognitive complaints secondary to poor sleep are documented in general adolescent populations.…”

“…7,33 These findings suggest that a shared mechanism of reduced metabolism and alteration in cerebral blood flow from preinjury sleep difficulties may interact with SRC to worsen concussion outcomes. 24 Given these findings, a study examining the role of baseline or preinjury levels of sleep-related problems on subsequent postinjury neurocognitive performance and symptoms is warranted.…”

“…Although recent research has suggested athletes with preinjury sleep difficulties are more symptomatic at baseline (eg, higher levels of somatic and cognitive complaints), it is unclear if these individuals' symptom presentation after an injury differs from athletes without preinjury sleep difficulties. 24,27 The primary purpose of this study was to compare neurocognitive impairment and symptoms among groups with and without self-reported sleep difficulties on baseline Postconcussion Symptom Scale (PCSS). We expected that athletes with preinjury sleep difficulties would report more concussion (or concussion-related) symptoms and would perform worse on neurocognitive tests, particularly reaction time and processing speed, at 3 postinjury time intervals compared with those without.…”

The influence of sleep duration and sleep-related symptoms on baseline neurocognitive performance among male and female high school athletes.

“…These findings were replicated across verbal and visual memory domains, RT, and also identified on visual motor speed. Visual examination of differences of raw mean scores across groups would suggest a doseresponse-like pattern for sleep deprivation within this study, consistent with McClure et al (2013). However, our study was highly powered and effect sizes were quite small, despite evaluating a more significant degree of sleep loss than prior studies.…”

“…Two prior studies found a statistically significant, although weak relationship between sleep duration/quality and neurocognitive test performance. Even with questionable clinical relevance, both studies suggested sleep is negatively related to overall baseline symptom reporting (McClure, Zuckerman, Kutscher, Gregory, & Solomon, 2013; Mihalik et al, 2013).…”