title: Predicting Recovery Patterns After Sport-Related Concussion.
abstract: BACKGROUND
  Clinicians sometimes treat concussed individuals who have amnesia, loss of consciousness (LOC), a concussion history, or certain symptom types more conservatively, but it is unclear whether recovery patterns differ in individuals with these characteristics.
  
  
  OBJECTIVE
  To determine whether (1) amnesia, LOC, and concussion history influence the acute recovery of symptoms, cognition, and balance; and (2) cognition and balance are influenced by acute symptom type.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Seven sports at 26 colleges and 210 high schools.
  
  
  METHODS
  A total of 8905 collegiate (n = 1392) and high school (n = 7513) athletes.
  
  
  METHODS
  The Graded Symptom Checklist, Standardized Assessment of Concussion, and Balance Error Scoring System were administered to all athletes during the preseason. To allow us to track recovery patterns, athletes diagnosed with a concussion (n = 375) repeated these assessments immediately after the injury, 3 hours postinjury, 1 day postinjury, and at 2, 3, 5, 7, and 90 days after injury.
  
  
  RESULTS
  Athletes who experienced amnesia had markedly greater deficits in and a slower recovery trajectory on measures of symptoms, cognition, and balance. Athletes with 2 or more prior concussions demonstrated poorer balance than those with no previous history. Otherwise, LOC and concussion history largely did not affect symptoms, cognition, or balance. Greater deficits in balance scores were observed in athletes with all symptom types. Regardless of these characteristics, most athletes recovered within 7 to 10 days.
  
  
  CONCLUSIONS
  Athletes who experienced amnesia had more symptoms and greater deficits in cognition and balance. Symptoms and cognitive or balance deficits were not consistently associated with LOC or concussion history. Acute symptoms had a strong influence on balance scores and, to a lesser extent, on cognition. However, we found no evidence to support more cautious return-to-play decisions for athletes with these characteristics, as group recovery occurred within normal timelines. Our study supports current clinical practice: recommending that athletes be withheld from activity until they are asymptomatic, followed by a graduated return-to-play progression.
authors.affiliation: Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, and Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine.
authors.forename: Elizabeth F
authors.initials: EF
authors.lastname: Teel
authors.affiliation: Injury Prevention Research Center, and.|Department of Epidemiology, The University of North Carolina at Chapel Hill.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Marshall
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Shankar
authors.forename: Michael
authors.initials: M
authors.lastname: McCrea
authors.affiliation: Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, and Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine.|Injury Prevention Research Center, and.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Guskiewicz
mesh_terms: D000293:Adolescent; D000328:Adult; D000647:Amnesia / Q000209:etiology; D056352:Athletes / Q000706:statistics & numerical data; D001265:Athletic Injuries / Q000175:diagnosis / Q000534:rehabilitation*; D001924:Brain Concussion / Q000175:diagnosis / Q000534:rehabilitation*; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology / Q000534:rehabilitation; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D004856:Postural Balance / Q000502:physiology; D000068958:Return to Sport / Q000502:physiology; D012574:Schools; D013177:Sports / Q000502:physiology; D014495:Universities
keywords: Balance Error Scoring System; Standardized Assessment of Concussion; return to play; traumatic brain injuries