Head Impacts in Contact Sports Linked to Brain Changes in Athletes

Concussions are a serious issue in sports. In fact, recent findings have shown that they can influence a person for years to come. Yet it's not just concussions that athletes have to worry about. Scientists have discovered that repeated blows to the head during a season of contact sports may cause changes in the brain's white matter and affect cognitive abilities even if none of the impacts resulted in a concussion.

In order to better examine sports-related injuries, the researchers used a form of magnetic resonance imaging, or MRI. Using this method, the scientists looked at two groups of Dartmouth athletes: 80 football and ice hockey players in the contact sports group and 79 athletes in the noncontact sports group. The football and hockey players wore helmets equipped with accelerometers; this allowed the researchers to compile the number and severity of impacts to the athletes' heads. Players that suffered from concussion during the season were not included in the analysis.

"The contact sports and noncontact-sports groups differed, and the number of times the contact sports participants were hit, and the magnitude of the hits they sustained, were correlated with changes in the white matter measures," said Thomas McAllister, one of the researchers, in a news release. "This study raises the question of whether we should look not only at concussions but also the number of times athletes receive blows to the head and the magnitude of those blows, whether or not they are diagnosed with a concussion."

That said, the new study didn't find large-scale or systematic differences in the brain scan measures. This, in particular, is somewhat reassuring. Yet the findings do suggest that some athletes may be more susceptible to repeated head impacts that do not involve concussions, though more research is necessary to determine how to identify those athletes. In addition, more research needs to be conducted in order to determine whether the effects of the head impacts are long-lasting or permanents, and whether they are cumulative.

The findings are published in the journal Neurology.