Jan 29, 2015
Brains Not Healing in Offseason

By Mary Kate Murphy

For football players, the offseason is a time traditionally for rest, recovery, and performance building. When the athletes show up for August two-a-days, their bodies should be healed from the previous year’s contact. However, a recent University of Rochester study has shown that this might the case when it comes to players’ brains–even those that didn’t sustain a concussion.
For the investigation, which was published on April 16 in the journal PLOS ONE, researchers examined the brains of 10 University of Rochester football players before and immediately after the 2011 season and then again six months into the offseason. During practices and games, the athletes wore accelerometers inside their helmets so researchers could track and record the severity of hits the athletes endured. Their brains were monitored through diffusion tensor imaging (DTI), and balance, cognitive, and blood tests kept track of changes in the body. The athletes’ data was compared to a control group of five college students who didn’t participate in sports.

Although the findings showed that the players experienced between 431 and 1,850 hits to the head over the course of the season, none resulted in a concussion. However, when the athletes were evaluated six months into the offseason, DTI scans showed that roughly half their brains underwent changes that reflected changes consistent with mild brain injury. Researchers found that as few as 10 to 15 hard hits to the head caused modifications to a player’s white matter–the inner layer of the brain composed of message-transmitting nerve fibers.

“There was really no recovery as a group–individually, there were a few players who recovered back to the baseline, but a majority did not,” Jeffrey Bazarian, MD, Associate Professor of Emergency Medicine at the University of Rochester School of Medicine and Dentistry and the study’s lead author, told U.S. News and World Report. “There are many injuries that get better with time–muscle injuries, bone injuries, cartilage injuries. I don’t think we knew to what extent a brain injury was going to get better. To see that it didn’t really get better at all was really a surprise.”

The results showed that inflammation might play a role in indicating how well a player is recovering. Blood samples that showed an athlete’s brain was less swollen six months into the offseason typically meant that he was closer to full healing.

“What is an adequate rest period? We don’t know,” Bazarian said in a university press release. “Six months may be enough for some players but not for others. The autoimmune response and inflammation we observed in the blood of players who didn’t recover could be a result of genetics, diet, or other factors, but it was not the result of a concussion, since none of the athletes suffered one.”

Future examinations are in the works to follow up with this study’s findings. Bazarian and his team of researchers have added 10 additional players to the data and collaborated with Harvard University Medical School and the Cleveland Clinic to focus exclusively on inflammatory markers in players’ blood and how they compare to DTI images in the brain.

Bazarian said that the full impact of the white matter changes found in this study might not be known until several decades have passed. Until then, he advises caution.

“I don’t want to be an alarmist, but this is something to be concerned about,” he said.

The full text of the study, “Persistent, Long-term Cerebral White Matter Changes after Sports-Related Repetitive Head Impacts,” can be found at:

Mary Kate Murphy is an Assistant Editor at Training & Conditioning.

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