title: The King-Devick test and sports-related concussion: study of a rapid visual screening tool in a collegiate cohort.
abstract: OBJECTIVE
  Concussion, defined as an impulse blow to the head or body resulting in transient neurologic signs or symptoms, has received increasing attention in sports at all levels. The King-Devick (K-D) test is based on the time to perform rapid number naming and captures eye movements and other correlates of suboptimal brain function. In a study of boxers and mixed martial arts (MMA) fighters, the K-D test was shown to have high degrees of test-retest and inter-rater reliability and to be an accurate method for rapidly identifying boxers and mixed martial arts fighters with concussion. We performed a study of the K-D test as a rapid sideline screening tool in collegiate athletes to determine the effect of concussion on K-D scores compared to a pre-season baseline.
  
  
  METHODS
  In this longitudinal study, athletes from the University of Pennsylvania varsity football, sprint football, and women's and men's soccer and basketball teams underwent baseline K-D testing prior to the start of the 2010-11 playing season. Post-season testing was also performed. For athletes who had concussions during the season, K-D testing was administered immediately on the sidelines and changes in score from baseline were determined.
  
  
  RESULTS
  Among 219 athletes tested at baseline, post-season K-D scores were lower (better) than the best pre-season scores (35.1 vs. 37.9s, P=0.03, Wilcoxon signed-rank test), reflecting mild learning effects in the absence of concussion. For the 10 athletes who had concussions, K-D testing on the sidelines showed significant worsening from baseline (46.9 vs. 37.0s, P=0.009), with all except one athlete demonstrating worsening from baseline (median 5.9s).
  
  
  CONCLUSIONS
  This study of collegiate athletes provides initial evidence in support of the K-D test as a strong candidate rapid sideline visual screening tool for concussion. Data show worsening of scores following concussion, and ongoing follow-up in this study with additional concussion events and different athlete populations will further examine the effectiveness of the K-D test.
authors.affiliation: Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Galetta
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Brandes
authors.forename: Karl
authors.initials: K
authors.lastname: Maki
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dziemianowicz
authors.forename: Eric
authors.initials: E
authors.lastname: Laudano
authors.forename: Megan
authors.initials: M
authors.lastname: Allen
authors.forename: Kathy
authors.initials: K
authors.lastname: Lawler
authors.forename: Brian
authors.initials: B
authors.lastname: Sennett
authors.forename: Douglas
authors.initials: D
authors.lastname: Wiebe
authors.forename: Steve
authors.initials: S
authors.lastname: Devick
authors.forename: Leonard V
authors.initials: LV
authors.lastname: Messner
authors.forename: Steven L
authors.initials: SL
authors.lastname: Galetta
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D001924:Brain Concussion / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D015331:Cohort Studies; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D013177:Sports / Q000502:physiology; D013334:Students; D013997:Time Factors; D014495:Universities; D055815:Young Adult