Blows to the Head May Cause Brain Changes
Even without a concussion, blows to the head may damage the brain. Researchers found that football athletes and ice hockey players who suffered blows to the head showed changes in their learning and memory abilities.
Researchers explain that blows to the heard may affect the brains' white matter, the tissue that plays an important role in speeding up nerve signals.
"We found differences in the white matter of the brain in these college contact sport athletes compared to non-contact sport varsity athletes," study author Thomas W. McAllister, MD, of Indiana University School of Medicine in Indianapolis, said in a news release. "The degree of white matter change in the contact sport athletes was greater in those who performed more poorly than expected on tests of memory and learning, suggesting a possible link in some athletes between how hard/often they are hit, white matter changes, and cognition, or memory and thinking abilities."
The latest research involved 80 concussion-free varsity football and ice hockey players who wore helmets that recorded the acceleration-time of the head following impact. The players were compared to 79 non-contact sport athletes in activities such as track, crew and Nordic skiing. The athletes were evaluated before and shortly after the season with brain scans and learning and memory tests.
The findings revealed that a total of 20 percent of the contact players and 11 percent of the non-contact athletes scored more than 1.5 standard deviations below the predicted score. These athletes also showed more change in the corpus callosum, a region of the brain that connects the right and left sides of the brain, than the athletes who scored as predicted on the test.
"This group of athletes with different susceptibility to repetitive head impacts raises the question of what underlying factors might account for the changes in learning and memory, and whether those effects are long-term or short-lived," said McAllister.