College football players who sustain multiple concussions are at risk for a decline in long-term neuropsychological function. And players with a pre-existing learning disability (LD) who have sustained multiple concussions appear to have an even higher risk of permanent injury, according to an article in the Sept. 8 issue of the Journal of the American Medical Association (JAMA).
The study is the first of its kind to determine long-term effects of concussions on athletes' neuropsychological activity, which for example includes memory, problem solving, speed of information processing and fine motor speed.
"The chance that a college football player has had a concussion playing football, either before or during college is very high û about one in three," according to the study's lead author Michael Collins, Ph.D., from the Division of Neuropsychology at Henry Ford Health System, Detroit. "Our study revealed that more than two-thirds of quarterbacks and tightends had experienced at least one concussion, while one-third of running backs/fullbacks had a history of concussion."
Dr. Collins and colleagues studied 393 male college football players from four Division IA programs: Michigan State University, University of Florida, University of Pittsburgh and University of Utah. Prior to the 1997/98 and 1998/99 seasons, athletes were interviewed about their medical history and were administered a 30-minute battery of written and verbal neuropsychological tests to establish baseline readings.
When an athlete sustained a concussion during the football season, he was again given the neuropsychological tests. Post-concussion analysis showed:
- Within 24 hours, performance of concussed athletes was noticeably poorer in the areas of verbal learning, memory and speed of information processing.
- Deficits in these areas were detected up to five days later.
"It is a misconception that concussion always results in a loss of consciousness," Dr. Collins says. "Many other symptoms exist including confusion, memory loss or slowed mental processing. We recommend that an athlete be free of all symptoms before returning to play. The tests administered in this study allow us to thoroughly measure brain function and make more informed decisions."
Dr. Collins continues: "And for players who have sustained more than one concussion over their career, we need to be even more cautious because our study showed the damage can last years."
Of the players involved in the study, one in five had sustained two or more concussions during their career. These players demonstrated the greatest signs of long-term neurological damage, especially if they had a learning disability.
"Players with multiple concussions and an LD performed significantly more poorly on problem solving and information processing tests than players with multiple concussions who had no history of LD," Dr. Collins says.
Moreover, the study revealed a relationship between athletes who experienced multiple concussions and the likelihood of a learning disability. Of the 393 athletes, 13.5 percent had a learning disability -- defined as difficulty with retention and use of listening, speaking, writing, reading, reasoning or mathematical skills.
Of players with no prior concussions, about 10 percent had an LD. But among players with one concussion almost 15 percent had an LD, and among those with two or more concussions 19 percent had an LD.
"We don't know whether concussions cause learning disability, or players with a learning disability are more vulnerable to sustaining concussions," Dr. Collins says. "But our study revealed a trend that warrants further investigation to see why these players are at risk of impaired neurological function."
The composition of the study's pool was Caucasian (48 percent), African American (46 percent), Polynesian American (4 percent), Asian American and Hispanic American (each 1 percent). No racial differences were observed.
According to Dr. Collins, the best way to prevent long-term damage is for players to have neuropsychological testing before the season, and then to be re-tested after sustaining a concussion and before returning to play to make sure they have returned to their baseline level of function.
The battery of neuropsychological tests used in the study was initially developed for the Pittsburgh Steelers by Mark Lovell, Ph.D., division head of Neuropsychology at Henry Ford Health System.
A similar program to help guide return-to-play issues is now being used by the National Football League and the National Hockey League. Dr. Lovell serves as consultant to a number of professional sports organizations including the Steelers, Detroit Red Wings and Buffalo Sabres.
The study was funded in part by grants from the Arthur J. Rooney Endowment, Blue Cross/Blue Shield of Michigan and the University of Florida Golden Opportunity Program.