Objective: To test the hypothesis that there is an association between amateur boxing and chronic traumatic encephalopathy using neuropsychologic assessments.
Design: A prospective, controlled, blinded, observational, neuropsychologic study.
Setting: Amateur boxing clubs in Dublin, Ireland, March 1992 to April 2001.
Participants: Twenty randomly selected, actively competing, male amateur boxers and 20 age-matched, socio-economic controls.
Interventions: The boxers participated in amateur competition and sparring.
Main outcome measures: Raw scores and changes in scores over time were recorded in the following neuropsychologic tests: Trail Making Tests A and B, Digit Symbol, Finger Tapping (dominant and nondominant hands), modified versions of the Finger Tapping Tests, Paired-Associate Learning, Digit Span, Rey-Osterrieth Complex Figure Tests A and B, and Serial Addition. Raw scores and changes in scores for the two groups were compared, and a regression analysis was performed to detect any association between these values and exposure to boxing.
Results: The boxers showed superior performance in the Trail Making Tests A and B at all time points and an inferior performance in both standard Finger Tapping Tests at all time points except baseline for the dominant hand. This inferior performance was not found in the modified versions of the tests. The controls showed significant deterioration in their performance in the Rey-Osterrieth Complex Figure Tests A and B.
Conclusions: In this small controlled, prospective study of competitive amateur boxers, there was no evidence of neuropsychologic deterioration over 9 years. The amateur boxers demonstrated relative preservation and/or improvement of some neuropsychologic skills relative to the socioeconomic controls.