By Julie Steenhuysen
CHICAGO (Reuters) - New guidelines from the American Academy of Neurology say no U.S. athlete who has had a concussion should be allowed to resume play until all symptoms have passed, revising earlier guidelines that allowed some athletes back on the field after just a week on the sidelines.
"We now understand that there are some really profoundly bad possible outcomes either from two hits in a row or a lot of hits over a lifetime," said Dr. Jeffrey Kutcher, who chairs the sports neurology section of the American Academy of Neurology.
"There is evidence these injuries are more significant than we thought previously," Kutcher, a physician for the University of Michigan football team, said in a telephone interview.
The issue of concussions in sports has become a hot topic in the United States, in part due to violent hits by players in National Football League games. The NFL has taken new steps to protect its players from concussions, while sports teams at the college and high school level also have devoted more attention to the issue.
"Those things really don't allow us to predict how long the injury is going to last," Kutcher said.
Concussions have become an increasing concern among professional athletes. Earlier this month, the NFL said it would fine three players for dangerous hits -- including helmet-to-helmet crashes -- that violated player safety rules.
The U.S. Centers for Disease Control and Prevention estimates Americans have 3 million concussions each year. Among those aged 15 to 24, sports are second only to car accidents as the leading cause of traumatic brain injury.
Under the new recommendations, Kutcher said athletes who have had a concussion will need to have a series of phased tests to make sure the brain is fully recovered.
Kutcher said estimates of the number of athletes who have had a concussion have been climbing in recent years, partly because more people are playing contact sports, young athletes are training more aggressively at an earlier age and doctors are more aggressive about diagnosing concussions, which 90 percent of the time do not involve loss of consciousness.
Often, concussions are not reported or caught.
In a study by researchers at Purdue University in Indiana, a team fitted 21 players at a local high school with special helmets equipped with sensors that monitored impact.
They compared data from each player with brain scans and tests done before, during and after each season. And they shot video of each play to see how they were hit.
Kutcher said the new position statement on concussions is meant to reflect new research. He said the group will release practice guidelines for doctors after it has finished an exhaustive review of the scientific literature.
(Editing by Cynthia Osterman)
