title: The effect of preinjury sleep difficulties on neurocognitive impairment and symptoms after sport-related concussion.
abstract: BACKGROUND
  Researchers have reported that sleep duration is positively related to baseline neurocognitive performance. However, researchers have yet to examine the effect of preinjury sleep difficulties on postconcussion impairments.
  
  
  OBJECTIVE
  To compare neurocognitive impairment and symptoms of athletes with preinjury sleep difficulties to those without after a sport-related concussion (SRC).
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  The sample included 348 adolescent and adult athletes (age, mean ± SD, 17.43 ± 2.34 years) with a diagnosed SRC. The sample was divided into 2 groups: (1) 34 (10%) participants with preinjury sleep difficulties (sleeping less as well as having trouble falling asleep; SLEEP SX) and (2) 231 (66%) participants without preinjury sleep difficulties (CONTROL). The remaining 84 (24%) participants with minimal sleep difficulties (1 symptom) were excluded. Participants completed the Immediate Postconcussion Assessment and Cognitive Test (ImPACT) and Postconcussion Symptom Scale (PCSS) at baseline and 3 postinjury intervals (2, 5-7, and 10-14 days after injury). A series of repeated-measures analyses of covariance with Bonferroni correction, controlling for baseline non-sleep-related symptoms, were conducted to compare postinjury neurocognitive performance between groups. Follow-up exploratory t tests examined between-group differences at each time interval. A series of analyses of variance were used to examine total PCSS score, sleep-related, and non-sleep-related symptoms across time intervals between groups.
  
  
  RESULTS
  Groups differed significantly in PCSS scores across postinjury intervals for reaction time (P < .001), with the preinjury SLEEP SX group performing worse than controls at 5-7 days (mean ± SD, 0.70 ± 0.32 [SLEEP SX], 0.60 ± 0.14 [CONTROL]) and 10-14 days (0.61 ± 0.17 [SLEEP SX]; 0.57 ± 0.10 [CONTROL]) after injury. Groups also differed significantly on verbal memory performance (P = .04), with the SLEEP SX (68.21 ± 18.64) group performing worse than the CONTROL group (76.76 ± 14.50) 2 days after injury. The SLEEP SX group reported higher total symptom (P = .02) and sleep-related symptom (P = .02) scores across postinjury time intervals.
  
  
  CONCLUSIONS
  Preinjury sleep difficulties may exacerbate neurocognitive impairment and symptoms after concussion. The findings may help clinicians identify athletes who are at risk for worse impairments after a concussion due to preinjury sleep difficulties.
authors: Department of Orthopaedic Surgery, UPMC Sports Medicine Concussion Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors: Alicia
authors: A
authors: Sufrinko
authors: Department of Orthopaedic Surgery, UPMC Sports Medicine Concussion Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors: Kelly
authors: K
authors: Pearce
authors: Department of Health, Human Performance and Recreation, Office of Sport Concussion Research, University of Arkansas, Fayetteville, Arkansas, USA.
authors: R J
authors: RJ
authors: Elbin
authors: Department of Kinesiology, Michigan State University, East Lansing, Michigan, USA.
authors: Tracey
authors: T
authors: Covassin
authors: Department of Orthopaedic Surgery, UPMC Sports Medicine Concussion Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors: Eric
authors: E
authors: Johnson
authors: Department of Orthopaedic Surgery, UPMC Sports Medicine Concussion Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors: Michael
authors: M
authors: Collins
authors: Department of Orthopaedic Surgery, UPMC Sports Medicine Concussion Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA akontos@pitt.edu.
authors: Anthony P
authors: AP
authors: Kontos
mesh_terms: D000293:Adolescent; D056352:Athletes; D001265:Athletic Injuries / Q000175:diagnosis / Q000503:physiopathology*; D001924:Brain Concussion / Q000150:complications* / Q000175:diagnosis / Q000209:etiology; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D009483:Neuropsychological Tests; D038223:Post-Concussion Syndrome / Q000453:epidemiology; D011930:Reaction Time / Q000502:physiology; D012893:Sleep Wake Disorders / Q000150:complications / Q000453:epidemiology*; D055815:Young Adult
keywords: concussion; injury; sleep problems