Combat Sports Law

In the latest article addressing injury issues in combative sports, a study was published last month in the Journal of Neurotrauma studying cognitive impairment from boxing.

The study, titled Chronic Effects of Boxing: DTI and Cognitive Findings, used Magnetic Resonance Imaging and Diffusion Tensor Imaging to study brain trauma among 10 boxers (9 active and 2 retired) and 9 other participants not involved in combative sports.

Unsurprisingly the study noted cognitive issues among the boxers and, consistent with other recent studies, pointed to the number of years involved in the sport, as an important factor leading to long term impairment.

To this point the study concluded “Years of boxing had the most consistent, negative correlations with FA, ranging from -0.65 for the right ventral striatum to -0.92 for the right cerebral peduncle. Years of boxing was negatively related to the number of words consistently recalled over trials (r=-.74, p=0.02), delayed recall (r=-0.83, p=0.003), and serial RT, (r=.66, p=0.05).”

The full abstract can be found here –

We used magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to evaluate the effects of boxing on brain structure and cognition in 10 boxers (8 retired, 2 active) (mean age=45.7 years, SD=9.71) and nine participants (mean age=43.44, SD=9.11) in non-combative sports. Evans Index (maximum width of the anterior horns of the lateral ventricles/maximal width of the internal diameter of the skull) was significantly larger in the boxers, (F=4.52, p=0.050; Cohen’s f=0.531). Word list recall was impaired in the boxers ((F1,14)=10.70, p=0.006, f=0.84)) whereas implicit memory measured by faster reaction time (RT) to a repeating sequence of numbers than to a random sequence was preserved t=2.52, p<0.04. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) measured by tractography did not significantly differ between the groups. However, DTI metrics were significantly correlated with declarative memory (e.g., left ventral striatum ADC with delayed recall, r=-0.74, p=0.02) and with RT to the repeating number sequence, (r=0.70, p=0.04) in the boxers. Years of boxing had the most consistent, negative correlations with FA, ranging from -0.65 for the right ventral striatum to -0.92 for the right cerebral peduncle. Years of boxing was negatively related to the number of words consistently recalled over trials (r=-.74, p=0.02), delayed recall (r=-0.83, p=0.003), and serial RT, (r=.66, p=0.05). We conclude that microstructural integrity of white matter tracts is related to declarative memory and response speed in boxers and to the extent of boxing exposure. Implications for chronic traumatic encephalopathy are discussed.