Research clears concussion picture for hockey

While concussions may be an unfortunate part of some high-impact sports, an international study involving Western researchers suggests a significant underestimation in the number of concussions being reported in hockey. And those findings may change how we play the good ol’ hockey game

“We cannot turn our collective heads when a concussion occurs. We must act collectively,” said principal investigator Dr. Paul Echlin, a former London sports medicine specialist. “One of my goals is to bring together people from all parts of society to collaborate in finding solutions for this significant public health issue. Let us work together – physicians, researchers, athletes, parents, coaches and first responders – in concussion prevention, identification, and treatment.”

The Hockey Concussion Education Project (HCEP) was conducted during a single Canadian Interuniversity Sports hockey season, between August 2011 and March 2012, and included 45 male and female university hockey players. A similar HCEP study was conducted in 2009-10.

Their findings, An overview of the basic science of concussion and subconcussion: where we are and where we are going, were published as part of a four-part series in the Journal of Neuroscience last month.

Western professor Andrew Johnson, Health and Rehabilitation Sciences chair, said each player underwent comprehensive pre-season baseline assessments. The study participants were also required to undergo MRI imaging pre- and post-season, as well as sequentially after any clinically diagnosed concussion.

Each regular season game was observed by a qualified physician and a neutral non-physician observer. Any player who suffered a suspected concussion was evaluated at the game. If a concussion diagnosis was made, the player was subsequently seen in the physician’s office for a full clinical evaluation, and MRI scans were repeated. Based on those evaluations, players were counselled on the decision of when to return to play.

At the end of the season, 11 concussions were physician-observed or self-reported in the 55 regular-season games. The incidence rate was three times greater for men and five times greater for women than the most ever reported in the literature for this age, gender, skill level and sport.

“It would certainly be safe to say that concussions are more prevalent in hockey than we have been lead to believe,” Johnson said.

While more than half of those who were diagnosed with a concussion admitted to at least one concussion in the past, what is more disturbing was the fact the study found 67 per cent of the hits observed to cause the concussions were to the head, and 83 per cent were described as purposeful.

“We don’t, at this time, have any data to suggest that concussions are decreasing among hockey players,” Johnson said. “The populations in the 2010 and 2012 studies are sufficiently different as to make direct comparisons difficult. It’s important to note, however, the concussions reported in both of the studies we have conducted are between three and five times higher than other comparable studies within the literature.”

While the primary enhancement of the methodology within this latest study was the inclusion of MRI, Johnson said the most interesting findings were found within the diffusion tensor imaging results, which allows doctors to visualize the location and orientation of the brain’s white matter tracts.

This imaging revealed changes in the microstructure of the brain’s white matter of hockey players between pre- and postseason scan. While two of the three concussed athletes showed the most pronounced changes most of the athletes showed an increase in diffusivity over the course of one season.

“What this suggests is that all of the players (even the non-injured players) showed signs of white matter alterations that are consistent with the kind of changes reported in mild traumatic brain injury,” Johnson said. He added this suggests we need to be concerned about the cumulative effects of subconcussive injuries sustained by the players throughout the season.

“Whether this means we need to evaluate rules concerning fights in hockey, return-to-play guidelines for players with clinically diagnosed concussions or whether there are medical-imaging techniques that may be useful in the screening of individuals that are at an increased liability for brain injury, is a matter for future research.”

While education and improved objective clinical tools are vital to decrease incidence and improve the care of the athlete, Johnson noted we must look primarily toward educating the next generation of coaches and parents.

“Not to discount the importance of proper equipment, and appropriate conditioning, but the most likely avenue for improvement is in the attitudes of players, coaches, and parents toward concussions in general, and towards return-to-play guidelines,” he said.

Along with Western, study participants in this first international study on concussion included Brigham and Women’s Hospital, Harvard Medical School and the Institute of Clinical Radiology, Ludwig-Maximilians-University, the University of Montreal, the University of British Columbia, and Indiana University.