Do cumulative mild head injuries in rugby affect neuropsychological performance? : a comparative study between club rugby players and non-contact sport athletes.

Abstract

Context: Concussion is a major sports medicine concern that is currently under scrutinisation worldwide. Well-publicised cases of careers ending due to multiple concussions, and the potential for permanent, disabling neurocognitive deficits have raised concerns and encouraged further research to take place. Objectives: This study aimed to investigate subjects exposed to mild head injuries with the aim of determining if neuro logical sequelae are detectable. The objectives of this study were to evaluate changes in neuropsychological performance over a period of playing rugby for one full season, which extended over nine months. This study investigated the relationship between concussion history and neuropsychological performance relating to the possible cumulative effects of concussion. Neuropsychological functioning in recently concussed athletes was compared with that of non-injured (control) athletes to detect whether neurological sequelae were present. Investigation into the relationship between post-concussion symptoms and neuropsychological performance was evaluated. The position of play was analysed to see if there were any measurable differences m neuropsychological performance present between forward and backline players. Design, Setting, and Participants: 35 club rugby players and 35 non-contact sports athletes were assessed over a period of 9 months. Both groups underwent pre-season baseline testing and post-season testing. A comprehensive battery of reliable and valid neuropsychological tests was used to assess these subjects, with particular focus on the following 5 areas of cognition: planning, visuo spatial and constructional ability; attention and concentration; memory; verbal fluency and speed of information processing. Results: The data showed that significant differences occurred in rugby players participating regularly in the sport over one full season in terms of changes in neuropsychological test performance in a range of cognitive domains, including planning, visual spatial and constructional ability, attention and concentration, memory and verbal fluency. Numerous significant relationships were found between certain Post Concussion Symptom Scale (PCSS) scores and poor neuropsychological performance, which were considered indicative of subtle effects of sub-concussive injuries and mild head injury (MHI). Surprisingly, following the assessment of concussed players during the season, the data did not show any reliable significant declines in cognitive performance compared to their baseline testing. However, mean scores of the concussed group did show a trend of decreased neuropsychological performance in almost every cognitive domain following the concussive injury. The data did not show any significant relationship between a history of three or more previous concussions and neuropsychological performance. Furthermore, no significant differences in neuropsychological performance between backline and forward players were evident. Conclusion: This research demonstrates that concussion can present serious consequences for athletes and warrants the attention it has received. This present study gives a clear description of the potential negative consequences of playing rugby, which are evident by looking at the change in scores between pre- and post-season testing and poorer performance in most neuropsychological measures following a concussive injury. Although this study dealt mainly with 'normal' players, the results shown here are a cause for concern. What has become evident is that the player need not be exposed to severe concussion in order to experience some form of cognitive impairments. Even if these impairments are minimal, they are however still present and have the potential of accumulating, which could lead to disastrous permanent deficits.