Longitudinal Changes in Regional Brain Volumes and Cognition of Professional Fighters With Traumatic Encephalopathy Syndrome.

Abstract

Due to current limitations in diagnosing Chronic Traumatic Encephalopathy (CTE) clinically, Traumatic Encephalopathy Syndrome (TES) has been proposed as the clinical presentation of suspected CTE. This study aimed to determine whether there was an association between a clinical diagnosis of TES and subsequent temporal decline in cognitive or MRI volumetric measures. This was a secondary analysis of the Professional Athletes Brain Health Study, inclusive of active and retired professional fighters over the age of 34. All athletes were adjudicated as TES positive (TES+) or negative (TES-) based on the 2021 clinical criteria. General linear mixed models were used to compare MRI regional brain volumes and cognitive performance between groups. A total of 130 fighters met inclusion criteria for consensus conference. Of these, 52 fighters (40%) were adjudicated as TES+. Athletes with a TES+ diagnosis were older and had significantly lower education. Statistically significant interactions and between-group total mean differences were found in all MRI volumetric measurements among TES+ compared to the TES- group. The rate of volumetric change indicated a significantly greater increase for lateral (estimate= 5196.65; 95% CI= 2642.65, 7750.66) and inferior lateral ventricles (estimate= 354.28; 95% CI= 159.90, 548.66) and a decrease for the hippocampus (estimate = -385.04, 95% CI= -580.47, -189.62), subcortical gray matter (estimate= -4641.08; 95% CI= -6783.98, -2498.18), total gray matter (estimate= -26492.00; 95% CI= -50402.00, -2582.32), and posterior corpus callosum (estimate= -147.98; 95% CI= -222.33, -73.62). Likewise, the rate of cognitive decline was significantly greater for reaction time (estimate= 56.31; 95% CI= 26.17, 86.45) and other standardized cognitive scores in the TES+ group. The 2021 TES criteria clearly distinguishes group differences in the longitudinal presentation of volumetric loss in select brain regions and cognitive decline among professional fighters 35 and over. This study suggests that a TES diagnosis may be useful in professional sports beyond football, such as boxing and mixed martial arts. These findings further suggest that the application of TES criteria may be valuable clinically in predicting cognitive decline.