Article Text

PDF
Cognition in the days following concussion: comparison of symptomatic versus asymptomatic athletes
  1. A Collie1,
  2. M Makdissi1,
  3. P Maruff2,
  4. K Bennell1,
  5. P McCrory1
  1. 1Centre for Health, Exercise and Sports Medicine, University of Melbourne, Parkville, Victoria, Australia
  2. 2School of Psychological Science, La Trobe University, Bundoora, Victoria, Australia
  1. Correspondence to:
 Dr A Collie
 c/o 92b Abbeville Road, London SW4 9NA, UK; acollie{at}unimelb.edu.au

Abstract

Background: Concussion is a common neurological injury occurring during contact sport. Current guidelines recommend that no athlete should return to play while symptomatic or displaying cognitive dysfunction. This study compared post-concussion cognitive function in recently concussed athletes who were symptomatic/asymptomatic at the time of assessment with that of non-injured (control) athletes.

Methods: Prospective study of 615 male Australian Rules footballers. Before the season, all participants (while healthy) completed a battery of baseline computerised (CogSport) and paper and pencil cognitive tasks. Sixty one injured athletes (symptomatic = 25 and asymptomatic = 36) were reassessed within 11 days of being concussed; 84 controls were also reassessed. The serial cognitive function of the three groups was compared using analysis of variance.

Results: The performance of the symptomatic group declined at the post-concussion assessment on computerised tests of simple, choice, and complex reaction times compared with the asymptomatic and control groups. The magnitude of changes was large according to conventional statistical criteria. On paper and pencil tests, the symptomatic group displayed no change at reassessment, whereas large improvements were seen in the other two groups.

Conclusion: Injured athletes experiencing symptoms of concussion displayed impaired motor function and attention, although their learning and memory were preserved. These athletes displayed no change in performance on paper and pencil tests in contrast with the improvement observed in asymptomatic and non-injured athletes. Athletes experiencing symptoms of concussion should be withheld from training and competition until both symptoms and cognitive dysfunction have resolved.

  • ASYMP, asymptomatic
  • CHRT, choice reaction time
  • CONT, control
  • CXRT, complex reaction time
  • DIVA, divided attention
  • DSST, Digit Symbol Substitution Task
  • LOC, loss of consciousness
  • LRN, continuous learning
  • MATCH, matching
  • OBK, one-back
  • PTA, post-traumatic amnesia
  • SRT, simple reaction time
  • SYMP, symptomatic
  • TBI, traumatic brain injury
  • TMT, Trail Making Test—part B
  • WSD, within subject standard deviation
  • cognition
  • concussion
  • mild traumatic brain injury
  • neuropsychology
  • symptoms

Statistics from Altmetric.com

Footnotes

  • Competing interests: For the duration of this study, Drs Collie and Maruff were employees of CogState Ltd, the manufacturers of the cognitive test used in this study

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.