A new study of sports programs at three major universities has revealed that the diagnoses of concussions is based mostly on the athletes’ subjective symptoms — which vary greatly — and researchers suggest this method is not the best way to determine the risk for future problems.
The research is part of a larger five-year investigation at Brown University, Dartmouth College and Virginia Tech in which researchers studied the biomechanical basis of concussions and the effects of repeat impacts to the head.
According to the results, the term “concussion” in a sports setting may differ from how it is used in other medical contexts, possibly confusing the symptoms which could lead to a false diagnosis.
“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,” said Ann-Christine Duhaime, M.D., director of the Pediatric Brain Trauma Lab at Massachusetts General Hospital, who led the study.
“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.”
For the study, 450 students — athletes from 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 practice, scrimmages and games.
Team trainers and doctors followed their usual methods for assessing and diagnosing potential concussions and prescribing treatment.
During the study period, over 486,000 head impacts were recorded in the participants. Concussions were diagnosed in 44 participants; four of these were diagnosed a second time for a total of 48 concussions.
A specific impact was linked to 31 of the diagnosed concussions, but no clearly associated impact was identified in the other 17 instances. The most common symptoms were mental cloudiness, headache and dizziness, and only one athlete lost consciousness.
An immediate diagnosis was made only six times, and many of the athletes did not begin experiencing symptoms until several hours after the game.
Even though measured head impacts in those diagnosed with concussions tended to be higher, some concussion-associated impacts had considerably less measured acceleration/deceleration of the head.
The researchers note that the head injuries reported in this study contrast those typically seen in emergency departments, in which a single, clearly identified head impact is usually associated with immediate changes in consciousness.
The authors add that there is a need for accurate tools to determine which patients have impacts that may harm the brain in significant ways.
Currently used criteria based on reported symptoms may be unreliable predictors of actual injury to the brain. They suggest replacing the single term “concussion” with a concussion spectrum.
“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.”
The research is published in the Journal of Neurosurgery.
Source: Massachusetts General Hospital