The human brain has a barrier that functions sort of like a teabag; oxygen and nutrients to pass into the brain while bloodborne pathogens and toxins are blocked. A team of researchers at Trinity College (Dublin) and Stanford found preliminary evidence of damage to this protective barrier in adolescent and adult rugby players, even in the absence of a concussion.

The team then moved to studying MMA athletes, measuring precisely if impact forces were damaging the blood-brain barrier. Co-senior author of the study and assistant professor of bioengineering at Stanford, David Camarillo, Ph.D., developed a mouth guard that tracks speed, acceleration, and force. Five pro MMA fighters worse the mouthguard during fights, and had their brain MRI scanned pre and post-event.

The scans showed the increased blood-brain barrier breakdown observed in rugby players, and further, certain measurements from the mouth guards correlated with the level of observed blood-brain barrier disruption. However, not every blow that looked bad, like a Round 1 KO inside 2 minutes, caused blood-brain barrier disruption.

The conventional wisdom is that when the head is struck forcefully, the brain slams against the inside of the skull, and then bounces, striking the other side. However, this study suggests that head trauma’s effects are felt much deeper in the brain.

The researchers next plan to conduct a similar study with a larger number of athletes. They are further interested in understanding whether the blood-brain barrier disruptions heal on their own and, if so, how long that takes. Long term, the team hopes that the imaging technique used in this study could one day be used to figure out how much damage an athlete has sustained, and when he or she can return to play.

h/t Stanford.edu