Concussion Research Expands as High School Football Season Continues

As football teams take to fields across the nation, Purdue University researchers continue work to uncover how repeated head impacts affect high school athletes.

Findings could aid efforts to develop safety guidelines based on the number of hits a football player should receive and also may help determine techniques that coaches and players might use to reduce the severity of blows to the head, said Eric Nauman, an associate professor of mechanical engineering and an expert in the central nervous system and musculoskeletal trauma.

Researchers have completed a two-year study of high school football players, and new findings are expected to be published later this year.

Helmet-sensor impact data from each player were compared with brain-imaging scans and cognitive tests performed before, during and after each season. The researchers also shot video of each play to record and study how the athletes sustained impacts.

The researchers evaluated players using a type of brain imaging technology called functional magnetic resonance imaging, or fMRI, along with a computer-based neurocognitive screening test. The fMRI scans reveal which parts of the brain are most active during specific tasks.

Thomas Talavage, an expert in functional neuroimaging and co-director of the Purdue MRI Facility, said the scans are revealing changes in mental processes among many players who do not show clinical signs of concussion.

"The number of hits and the distribution of impacts on different parts of the brain are directly related to the changes we are seeing in the fMRI data," Talavage said.

Annually in the United States, 135,000 youths ages 5-18 are treated in emergency rooms for sports- and recreation-related traumatic brain injuries, including concussions. Children and teens are more likely to get a concussion and take longer to recover than adults.

A new Indiana law requires student-athletes to be removed immediately from athletic activities if it is suspected they have suffered a head injury. In order to return to play, injured athletes must be evaluated and cleared by a health-care provider trained in head injury assessment. In addition to Indiana, several states have passed laws governing the management of suspected head injury to school-aged athletes ranging from classes for coaches and referees to removal from play and evaluation by a physician trained in head injury assessment.

The researchers are expanding to an additional high school football team and both boys' and girls' soccer teams.

"We want to increase the number of football players in the study and also include soccer to study athletes who don't wear head protection," Nauman said. "We also want to include girls to see whether they are affected differently than boys."

Findings from the football research represent a dilemma because they suggest athletes may suffer a form of injury that is difficult to diagnose.

"Most clinicians would say that if you don't have any concussion symptoms you have no problems," said Larry Leverenz, an expert in athletic training and a clinical professor of health and kinesiology. "However, we are finding that there is actually a lot of change, even when you don't have symptoms."

Players in the study received 200-1,800 hits to the head in a single season, with two players receiving the maximum number. Helmet-sensor data indicated impact forces to the head ranged from 20 Gs to more than 100 Gs.

"The worst hit we've seen was almost 300 Gs," Nauman said.

A soccer player "heading" a ball experiences an impact of 20-50 Gs.

Findings could aid efforts to develop more sensitive and accurate methods for detecting cognitive impairment and concussions; more accurately characterizing and modeling cognitive deficits that result from head impacts; determining the cellular basis for cognitive deficits after a single impact or repeated impacts; and developing new interventions to reduce the risk and effects of head impacts.

The work is ongoing and is supported with grants from the Indiana State Department of Health Spinal Cord and Brain Injury Research Fund, General Electric Healthcare, and through the National Science Foundation and National Defense Science and Engineering Graduate Fellowships.

Researchers also will follow the case studies of players who take the most hits to see if there is evidence of permanent changes in brain structure using MRI scans.

The research group, called the Purdue Neurotrauma Group (PNG), also is studying ways to reduce traumatic brain injury in soldiers who suffer concussions caused by shock waves from explosions.