THE REAL IMPACT OF
A high school football player may take anywhere from 200 to 1,800 hits to the head during the course of a single season. Now Purdue Professors Eric Nauman, Thomas Talavage and Larry Leverenz are leading a team of researchers who are asking whether these impacts might impair the brain, even if a player shows no clinical signs of a concussion.
Findings could aid efforts to develop safety guidelines that stipulate the number of hits a high school player should receive and may help determine techniques that coaches and players might use to reduce the severity of blows to the head. The work has also led to the development of new shock-absorbing materials for football and military helmets.
Purdue Neurotrauma Group
Eric Nauman, Thomas Talavage and Larry Leverenz are part of the Purdue Neurotrauma Group, a collaborative research effort that combines expertise in clinical diagnosis and care, biomechanics, and neuroimaging.
Learning more about the effects of head impacts on young people is especially important, since their brains are still developing. Even though subtle damage doesn't always manifest as a concussion, it could affect the brain later in life.
The researchers studied football players for two seasons at Jefferson High School in Lafayette, Ind., where 21 players completed the study the first season and 24 the second season, including 16 repeating players.
"Over the two seasons we had six concussed players, but 17 of the players showed brain changes even though they did not have concussions," says Talavage, an expert in functional neuroimaging and co-director of the Purdue MRI Facility.
IMAGING THE BRAIN
The researchers have evaluated players using helmet sensors and a type of brain-scanning technology called functional magnetic resonance imaging, or fMRI, along with neurocognitive screening tests. The fMRI scans reveal which parts of the brain are most active during specific tasks that the players perform.
The scans are revealing changes in mental processes among many players who do not show clinical signs of concussion, Talavage says. "Clinicians would say that if you don't have any concussion symptoms you have no problems. However, we are finding that there is actually a lot of change, even when you don't have symptoms," says Larry Leverenz, director of Athletic Training Education, an expert in athletic training and a clinical professor in the Department of Health and Kinesiology.
"The changes in brain activity we are observing suggest that a player is using a different strategy to perform a mental task, and that is likely because functional capacity is reduced," he says. "Overall performance doesn't change, but brain activity changes, showing that certain areas are no longer being recruited to perform a task."
The findings suggest athletes may suffer undiagnosed head injuries and continue to play. The researchers hope to improve player safety.
The research has paved the way for development of new shock-absorbing materials that might be used in helmets to better protect players from head impacts, work funded by Purdue’s Trask Fund and Alfred E. Mann Institute for Biomedical Development.