Sports officials, from the high school and college levels to the NFL, have made strides in recent years to limit the risks of players’ head injuries, which can cause serious neurological and psychiatric problems. But a new study has found the criteria used to diagnose sports-related concussions are inconsistent at best.
The research, published in the Journal of Neurosurgery, examined sports programs at three major universities and found the way concussion is usually diagnosed — largely based on athletes' subjective symptoms — varies greatly and may not be the best way to determine who is at risk for future problems.
In addition, the researchers found the term "concussion" may be used differently by sports professionals than in medical settings, and that may hinder care and treatment.
Lead researcher Dr. Ann-Christine Duhaime, director of the Pediatric Brain Trauma Lab at Massachusetts General Hospital, said the findings spotlight the need for better definitions and diagnostic tools.
"The term 'concussion' means different things to different people, and it's not yet clear that the signs and symptoms we now use to make a diagnosis will ultimately prove to be the most important pieces of this complicated puzzle," she said. "Some patients who receive a diagnosis of concussion go on to have very few problems, and some who are not diagnosed because they have no immediate symptoms may have sustained a lot of force to the head with potentially serious consequences."
The new study is part of a larger examination of concussion and the effects of repeat impacts to the head underway at Brown University, Dartmouth College and Virginia Tech. For the research, about 450 students — members of all three schools' football teams, two women's and two men's ice hockey teams — wore helmets equipped with instruments that measured the frequency, magnitude, and location of head impacts during practices, scrimmages and games.
Trainers and doctors followed their standard procedures for assessing and diagnosing potential concussions and prescribing treatment.
During the five-year study more than 486,000 head impacts were recorded in participating athletes. Concussions were diagnosed in 44 participants, who reported mental cloudiness, headache and dizziness, among other symptoms. But an immediate diagnosis was made only six times, and many of the athletes did not begin experiencing symptoms until hours after the game.
Researchers concluded that current criteria, based on reported symptoms, are unreliable predictors of actual injury to the brain. They proposed replacing the single term “concussion” with the concept of a “concussion spectrum” to help refine diagnosis, care, and treatment.
"A lot of work is needed before we can understand to what extent patients' reported symptoms — compared to such factors as the actual force imparted to the brain, previous head injuries and genetic background — influence the eventual consequences of repeated head impacts, consequences that may vary from patient to patient," said Duhaime. "For now, however, it's sensible to err on the side of safety, realizing that more specific answers will take more time and research."