Although not combat sports related, an important study was published last month in journal Neuroimage: Clinical revealing the rapid toll on brain structure that a short span of repeated subconcussive hits can bring.
In the recent study titled “The Effect of Repetitive Subconcussive Collisions on Brain Integrity in Collegiate Football Players over a Single Football Season” the 20 NCAA football players had their brains imaged via multiple MRI sequences both before and after a single college football season. All of the participants were asymptomatic for signs of concussion at the start of the season with the authors noting “none of the athletes were recovering from, or were diagnosed with, a concussion during the period of study, or in the nine months prior to the pre-season evaluation.”
The study revealed statistically “significant” changes on imaging at the conclusion of the season. Of note, none of the players were diagnosed with a concussion during the season making the volume of subconcussive hits the most likely cause for the noted changes.
The authors concluded as follows:
In a study of clinically asymptomatic collegiate football athletes, statistically-significant MRI changes were observed that are likely a consequence of participation for one season at the NCAA Football Bowl Subdivision level. Specifically, these changes (at Post, relative to Pre) were found in measures derived from multiple MRI modalities: CBF, rs-fMRI, and SWI. Critically, these changes were greater in athletes who were more likely to have an impact history including larger average numbers of high-G impacts (≥ 80G). A linkage between high intensity impacts and neuroimaging-observed changes adds to the growing literature in support of the hypothesis that collision-sport athletes may be at increased risk of long-lasting changes to brain functional and structural integrity. Future work in larger cohorts and involving a broader array of integrated biomarkers will enable more precise identification of athletes who are at risk, and will facilitate development of intervention strategies to permit collision-sport participation with reduced risk.
While it goes without saying that combative sports have inherent dangers, this is yet another study stressing the need for combat sports participants to take measures to reduce exposure to sub concussive blows in training.