NEW YORK, Sep 07 (Reuters Health) -- Sports-related concussions can impair intellectual function, according to a series of studies published in the September 8th issue of The Journal of the American Medical Association.
Risks for concussion are especially high in contact sports such as football or soccer. "The chance that a college football player has had a concussion playing football, either before or during college, is very high -- about one in three," said Dr. Michael W. Collins of the Henry Ford Health System in Detroit, Michigan.
Collins' team of researchers examined the neuropsychological performance of nearly 400 US college football players -- 34% of whom had suffered at least one prior concussion.
They found that players with two or more previous concussions "performed significantly worse on tests" measuring memory, learning ability and other 'executive' brain function, as well as "speed of information processing." Players who had sustained one concussion appeared to suffer no long-term intellectual deficit, however.
In a second study, Dr. Erik Matser, from St. Anna Hospital in Geldrop, the Netherlands, and colleagues report similar findings from a study of amateur soccer players. "Compared with control athletes, amateur soccer players exhibited impaired performance on tests of planning... and memory," they write. They add that rates of intellectual impairment seemed to rise with increasing number of previous concussions.
There is some good news, however. Researchers Dr. David Thurman and Janet Guerrero, of the National Center for Injury Prevention and Control in Atlanta, Georgia, report that the annual number of persons hospitalized for head injury declined 51% between 1980 and 1995. The greatest drop -- 66% -- occurred among those ages 5 to 14 years. Throughout the period, the researchers report, hospitalizations of men outpaced hospitalizations of women by nearly 2 to 1.
A number of factors may account for the drop, they report, most importantly advances in injury prevention, especially those sustained in car accidents.
A fourth study found that sports-related concussions among high school athletes occur at different rates in different sports. Dr. John Powell and Kim Barber-Foss of Med Sports Systems in Iowa City, Iowa documented 23,566 injuries over a period of 3 years. According to the researchers, 1,219 (5.5%) of these injuries were described as "mild brain traumas."
While football posed the highest risk of mild brain trauma, other sports examined presented a risk of concussion as well. Football accounted for nearly two thirds of all brain trauma cases (63.4%), followed by wrestling (10.5%), girls' soccer (6.2%), boys' soccer (5.7%), girls' basketball (5.2%), boys basketball (4.2%), softball (2.1%), baseball (1.2%), field hockey (1.1%) and volleyball (0.5%).
In a commentary on the five papers, Dr. James Kelly of the Rehabilitation Institute of Chicago, Illinois, said "those who serve as athletic team physicians or as consultants for determining readiness of athletes to return to competition after (concussion) should develop a better appreciation of the consequences of concussion and more severe forms of traumatic brain injury"
Detroit researcher Collins agrees. "We recommend that an athlete be free of all symptoms before returning to play," he said in a statement. This is especially important for "players who have sustained more than one concussion over their career." For these athletes, "we need to be even more cautious because our study showed the damage can last years."
