title: Duration of cognitive impairment after sports concussion.
abstract: OBJECTIVE
  We sought to determine the duration of cognitive impairment after sports concussion.
  
  
  METHODS
  We conducted a study with a prospective design in which 729 athletes underwent preseason baseline testing by being administered a computerized neuropsychological test battery, followed by retesting at regular intervals after they sustained sports-related concussions. A control group consisting of nonconcussed athletes drawn from the same baseline population underwent testing at parallel intervals.
  
  
  RESULTS
  Cognitive impairment in this primarily American Academy of Neurology Grade II sample of boxing concussions was apparent on the day of injury and at 1 to 2 days postinjury. Recovery of cognitive performance occurred during the 3- to 7-day interval. Comparison with control subjects showed that absent or attenuated practice effects, in addition to frank deterioration from baseline, were indications of recent concussion.
  
  
  CONCLUSIONS
  The present findings of recovery during the 3- to 7-day interval postinjury are consistent with the American Academy of Neurology Grade II return-to-play practice parameters suggesting a 1-week time-out from participation in contact sports.
authors.affiliation: National Rehabilitation Hospital, Washington, District of Columbia 20010, USA. joseph.bleiberg@medstar.net
authors.forename: Joseph
authors.initials: J
authors.lastname: Bleiberg
authors.forename: Alison N
authors.initials: AN
authors.lastname: Cernich
authors.forename: Kenneth
authors.initials: K
authors.lastname: Cameron
authors.forename: Wenyu
authors.initials: W
authors.lastname: Sun
authors.forename: Karen
authors.initials: K
authors.lastname: Peck
authors.forename: P James
authors.initials: PJ
authors.lastname: Ecklund
authors.forename: Dennis
authors.initials: D
authors.lastname: Reeves
authors.forename: John
authors.initials: J
authors.lastname: Uhorchak
authors.forename: Molly B
authors.initials: MB
authors.lastname: Sparling
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Warden
mesh_terms: D000293:Adolescent; D000328:Adult; D001914:Boxing / Q000293:injuries*; D001924:Brain Concussion / Q000150:complications*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005500:Follow-Up Studies; D006801:Humans; D009483:Neuropsychological Tests; D011446:Prospective Studies; D020127:Recovery of Function; D013997:Time Factors; D015599:Trauma Severity Indices