Neurocognitive function across a spectrum of high contact sports

Background and Hypothesis: Neurocognitive function (NF) is thought to be impaired in individuals who suffer repeated blows to the head. Similarly, rugby players who have lost consciousness ≥ 3 times have a significantly reduced neurological performance to those who have no history (Gardner et al, 2010). Neurocognitive tests examine memory, mental agility and co-ordination, and are a sensitive method for detecting acute traumatic brain injury (TBI) (Capruso et al, 1992). In the current study, we hypothesised that neurocognitive function would be impaired in boxers and rugby players with a history of loss of consciousness (LOC), with the greatest impairment in boxers, relative to healthy controls. Method: Eight currently active professional male boxers aged 29 (mean) ± 3 (SD) years and 9 male rugby players (23±3 years) all with a history of LOC (4±4 LOC in 137±97 competitive rounds and 4±5 LOC in 13±6 playing years, respectively) were compared to seven physically active non-concussed male controls (30±7 years). A battery of psychometric tests was employed to measure NF, separated into 3 subcategorises; Memory: Ray Auditory Verbal Learning Test (RAVLT) spilt into 3 sections, total number of words remembered (A1-A5), total remembered from a new list (B1) and total recalled from memory from initial list (A6) and Digit Span Test forwards and backwards (RDF and RDB). Mental Agility: Trail Making Tests, A (TMTA) and B (TMTB) and the Digit Symbol Substitution Test (DSST). Visual-motor Coordination: Groove Pegboard Dexterity Test, using dominant (GPD) and non-dominant (GPND) hands. After confirmation of normality using Shapiro-Wilk W tests, data were analysed using a one-way ANOVA and Bonferonni corrected independent samples t-tests. Significance was established at Pandlt;0.05. Results: NF was clearly more impaired in boxers vs controls, whilst only partially declining in rugby players. *Pandlt;0.05 Boxers Vs Controls, †Pandlt;0.05 Boxers Vs Rugby, ‡Pandlt;0.05 Rugby Vs Controls Conclusion: These findings demonstrate that NF is progressively more impaired across the spectrum of contact sports and justifies its utility as a diagnostic tool of TBI. References: Capruso, et al, (1992). Neurol Clin, 10, 879-893. Gardner, et al, (2010). Archives of Clinical Neuropsychology, 25, 174-181.