Computerised cognitive assessment of concussed Australian Rules footballers

Background-"Paper and pencil" neuropsychological tests play an important ro le in the management of sports related concussions. They provide objective information on the athlete's cognitive function and thus facilitate decisio ns on safe return to sport. It has been proposed that computerised cognitiv e tests have many advantages over such conventional tests, but their role i n this domain is yet to be established. Objectives-To measure cognitive impairment after concussion in a case serie s of concussed Australian Rules footballers, using both computerised and pa per and pencil neuropsychological tests. To investigate the role of compute rised cognitive tests in the assessment and follow up of sports related con cussions. Methods-Baseline measures on the Digit Symbol Substitution Test (DSST), Tra il Making Test-Part B (TMT), and a simple reaction time (SRT) test from a c omputerised cognitive test battery (CogState) were obtained in 240 players. Tests were repeated in players who had sustained a concussive injury. A gr oup of non-injured players were used as matched controls. Results-Six concussions were observed over a period of nine weeks. At the f ollow up, DSST and TMT scores did not significantly differ from baseline sc ores in both control and concussed groups. However, analysis of the SRT dat a showed an increase in response variability and latency after concussion i n the injured athletes. This was in contrast with a decrease in response va riability and no change in latency on follow up of the control players (p<0 .02). Conclusion-Increased variability in response time may be an important cogni tive deficit after concussion. This has implications for consistency of an athlete's performance after injury, as well as for tests used in clinical a ssessment and follow up of head injuries.