A recent study on UR football players by Jeffrey Bazarian M.D. of the UR Medical Center (URMC) found that football players who experience repetitive head impacts (RHIs) over the course of a season display changes in the brain consistent with mild brain injury. The changes do not go away even after six months, the length of the football off-season.
The study, titled “Persistent, Long-term Cerebral White Matter Changes after Sports-Related Repetitive Head Impacts,” was conducted on ten players from the University’s football team as well as five non-athletes, who served as experimental controls, during the 2011-12 football season. Brains were scanned both pre- and post- season, as well as after a six month interval. Players were assessed for cognitive performance, balance, and physiological factors at all three points.
The results of the study showed that those who experienced multiple head impacts during the season had changes in the white matter structures of the brain, indicating injury. The severity of injury varied among players.
“The amount of brain injury they had was directly related to the amount of force they took to the head during the season,” Bazarian said in an interview.
The study used accelerometers mounted in players’ helmets to gauge the number of impacts sustained by the players as well as the force of the impacts. Players’ head impacts ranged from 431 hits to the head for a running back to 1,850 hits for a center.
Such impacts are described as sub-concussive events. They do not meet the criteria for a concussion, nor do they bring on similar symptoms. However, Bazarian acknowledges that sub-concussive events can be detrimental.
“Imagine hitting your head against a wall 430 times,” he said.
Bazarian was careful to also note that the mild brain injury exhibited by the players in the study did not have any effect on players’ cognitive performance.
“Whatever is happening on these scans is not reflected in how they’re able to use their brains day to day,” he said. He went on to add that “none of these players had any symptoms” of brain injury.
Changes in the players’ brains were found through the use of Diffusion Tensor Imaging (DTI), a method similar in appearance to an MRI scan.
DTI allows researchers to observe the flow of water in the brain. The direction of water flow can tell medical professionals if certain structures in the brain called axons are inflamed. That inflammation may be the result of an autoimmune response indicating a disruption in the blood brain barrier.
This was the topic of Bazarian’s previous work looking into sub-concussive events in athletes.
“We need to tie this all together with the first paper,” said Bazarian, speaking about the results of his most recent study.
Not all players who participated in the study showed long-term brain injuries.
“What was interesting was that there were a few players who seemed to recover with six months of rest,” Bazarian said. “It looks like […] the strength of their individual immune response had an influence on whether they recovered or not”.
Bazarian said he hopes future research will determine exactly what kind of role the immune system plays in recovering from brain injury.
For now, Bazarian hopes his work will not deter football enthusiasts, but merely show them how to play better.
“I’m pretty sure we can make the sport safer,” he said.
Mitchell is a member of the class of 2014.
