title: Time course of clinical and electrophysiological recovery after sport-related concussion.
abstract: OBJECTIVE
  Recent neuroimaging studies suggest that abnormalities in brain function after concussion exist beyond the point of observed clinical recovery. This study investigated the relationship between an index of brain dysfunction (traumatic brain injury [TBI] Index), concussion severity, and outcome.
  
  
  METHODS
  EEG was collected from forehead locations in 65 male athletes with concussion within 24 hours of concussion, with follow-up at 8 and 45 days postinjury. Neurocognitive and symptom assessments were also performed and used to classify subjects in mild or moderate concussion categories. Time to return to play was recorded.
  
  
  RESULTS
  The TBI Index was higher in the moderate than mild concussion group at injury, day 8, and day 45. The moderate group had increased symptoms and decreased cognitive performance only at the time of injury. At the time of injury, only the TBI Index was significantly associated with the length of time to return to play.
  
  
  CONCLUSIONS
  Recovery of brain function after sport-related concussion may extend well beyond the time course of clinical recovery and be related to clinical severity. An index of brain dysfunction may be an objective indicator of injury, recovery, and readiness to return to play. The relatively small sample indicates the need for further study on the time course of physiological recovery.
authors.affiliation: Department of Psychiatry, NYU School of Medicine, Brain Research Laboratories, New York, New York 10016, USA. leslie.prichep@nyumc.org
authors.forename: Leslie S
authors.initials: LS
authors.lastname: Prichep
authors.forename: Michael
authors.initials: M
authors.lastname: McCrea
authors.forename: William
authors.initials: W
authors.lastname: Barr
authors.forename: Matthew
authors.initials: M
authors.lastname: Powell
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Chabot
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001265:Athletic Injuries / Q000175:diagnosis / Q000503:physiopathology; D001924:Brain Concussion / Q000175:diagnosis* / Q000503:physiopathology; D015331:Cohort Studies; D004569:Electroencephalography / Q000379:methods*; D004594:Electrophysiology; D005500:Follow-Up Studies; D005538:Football / Q000293:injuries*; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D059906:Neuroimaging / Q000379:methods; D009483:Neuropsychological Tests; D020127:Recovery of Function / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult