(HealthDay News) – Fighters who are exposed to greater years of fighting and more fights per year have volumetric brain changes, and those who fight for nine or more years have impaired memory and processing speed.
To investigate the association between exposure variables, cognition, and magnetic resonance imaging (MRI) brain structural measures, Charles Bernick, MD, from the Cleveland Clinic, and colleagues analyzed 78 fighters (35 boxers, 43 mixed martial arts athletes) from the Professional Fighters Brain Health Study. Participants were divided into two groups based on the median years of fighting and underwent computerized cognitive testing and volumetric brain MRI.
The researchers found that greater years of fighting and a greater number of fights per year correlated with lower volumes of bilateral hippocampi, caudate, and thalamus. In the group with less than nine years of fighting, exposure variables did not correlate with cognitive measures; however, for those who fought for nine or more years, there was a negative association between fights per year and scores on tests of memory and processing speed. This association persisted, even after adjusting for age.
“Our study shows there appears to be a threshold at which continued repetitive blows to the brain begin to cause measurable changes in memory and thinking, despite brain volume changes that can be found earlier,” Bernick said in a statement.