title: Repeat concussions in the national football league.
abstract: BACKGROUND
  Repeat concussion is an important issue in the National Football League (NFL). An initial description of repeat injuries was published for 6 years (1996-2001).
  
  
  OBJECTIVE
  The characteristics and frequency of repeat concussion in the NFL have not changed in the subsequent 6 years (2002-2007).
  
  
  METHODS
  Case control.
  
  
  METHODS
  From 1996 to 2007, concussions were reported using a standardized form documenting signs and symptoms, loss of consciousness and medical action taken. Data on repeat concussions were analyzed for the 12 years and compared between the 2 periods.
  
  
  RESULTS
  In 2002-2007, 152 players had repeat concussions (vs 160 in 1996-2001); 44 had 3+ head injuries (vs 52). The positions most often associated with repeat concussion in 2002-2007 were the defensive secondary, kick unit, running back, and linebacker. The odds for repeat concussion were elevated for wide receivers, tight ends, and linebackers but lower than in the earlier period. During 2002-2007, over half of players with repeat concussion were removed from play, and fewer immediately returned (vs 1996-2001). The average duration between concussions was 1.25 years for 2002-2007 and 1.65 years for the 12-year period. Over 12 years, 7.6% of all repeat concussions occurred within 2 weeks of the prior concussion.
  
  
  CONCLUSIONS
  The defensive secondary, kick unit, running back, and linebacker have the highest incidence of repeat concussion. During 2002-2007, more than half of players with repeat concussion were removed from play, and only a fraction immediately returned. Although concussion was managed more conservatively by team physicians in the recent 6 years, repeat concussions occurred at similar rates during both periods.
authors.affiliation: Department of Neurology, Long Island Jewish Medical Center, New Hyde Park, New York and Department of Neurology, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Ira R
authors.initials: IR
authors.lastname: Casson
authors.forename: David C
authors.initials: DC
authors.lastname: Viano
authors.forename: John W
authors.initials: JW
authors.lastname: Powell
authors.forename: Elliot J
authors.initials: EJ
authors.lastname: Pellman