A Comparison of Cognitive Function in Former Rugby Union Players Compared with Former Non Contact Sport Players and the Impact of Concussion History
AimThis study investigated differences in cognitive function between former rugby and non contact sport players, and assessed the association between concussion history and cognitive function.MethodsOverall, 366 former players (mean standard deviation [SD] age 43.3 8.2 years) were recruited from October 2012 to April 2014. Engagement in sport, general health, sports injuries and concussion history, and demographic information were obtained from an online self report questionnaire. Cognitive functioning was assessed using the online CNS Vital Signs neuropsychological test battery. Cohen's d effect size statistics were calculated for comparisons across player groups, concussion groups (one or more self reported concussions versus no concussions) and between those groups with CNS Vital Signs age matched norms (US norms) Individual differences within groups were represented as SDs.ResultsThe elite rugby group (n 103) performed worse on tests of complex attention, processing speed, executive functioning, and cognitive flexibility than the non contact sport group (n 65) and worse than the community rugby group (n 193) on complex attention. The community rugby group performed worse than the non contact group on executive functioning and cognitive flexibility. Compared with US norms, all three former player groups performed worse on verbal memory and reaction time; rugby groups performed worse on processing speed, cognitive flexibility and executive functioning; and the community rugby group performed worse on composite memory. The community rugby group and non contact sport group performed slightly better than US norms on complex attention, as did the elite rugby group for motor speed. All three player groups had greater individual differences than US norms on composite memory, verbal memory and reaction time. The elite rugby group had greater individual differences on processing speed and complex attention, and the community rugby group had greater individual differences on psychomotor speed and motor speed. The average number of concussions recalled per player was greater for elite rugby and community rugby than non contact sport. Former players who recalled one or more concussions (elite rugby, 85 community rugby, 77 non contact sport, 23 had worse scores on cognitive flexibility, executive functioning, and complex attention than players who did not recall experiencing a concussion.ConclusionsPast participation in rugby or a history of concussion were associated with small to moderate neurocognitive deficits (as indicated by worse CNS Vital Signs scores) in athletes post retirement from competitive sport.
Sports Medicine