New Canadian research has found that NHL players who continue to play a game despite sustaining a concussion eventually end up missing more than 10 days of action.
The finding comes from a major University of Calgary study of concussions in the NHL, conducted over seven seasons from 1997 to 2004.
The study found that while the rate of concussions levelled out over the study period -- from a peak of 7.7 per 100 players during the 2000-01 season to 4.9 per 100 players during the 2003-04 season -- the number of days lost per concussion increased.
As well, the researchers found that in 27 per cent of cases in which a player with a concussion continued to play without being evaluated by a doctor, that player went on to lose more than 10 days of play. That's longer than the average of six days that most concussions sidelined players for.
"It may suggest concussion severity is increasing or it may suggest the physicians are being more conservative with management decision," said lead author Dr. Brian Benson of the Sport Medicine Centre at the University of Calgary's faculty of kinesiology.
The study authors note there are lots of reasons why players might not be diagnosed with a concussion during a game, including:
- the hit was not observed
- the player did not report his symptoms to medical staff
- symptoms only occurred after the game
- players simply did not recognize their symptoms because of their concussion
As for why players who aren't diagnosed with a concussion until later end up staying out of the game longer, the authors write: "It is possible that continued exertion in the immediate post-concussion period may exacerbate the injury or increase a player's susceptibility to further injury, which may ultimately increase severity and prolong recovery."
The study comes as Pittsburgh Penguins captain Sidney Crosby prepares to enter his fourth month off the ice, following two head blows earlier this year.
Crosby is believed to have suffered a concussion in the Winter Classic on New Year's Day, but the brain injury wasn't diagnosed at the time. He was dealt another hit in his next game, and has been benched ever since.
The NHL and NHL Players Association have been systematically collecting data since 1997 with members of the NHL/NHLPA Concussion Working Group, analyzing and discussing the data on a regular basis.
Today's study results appear in the Canadian Medical Association Journal.
The study looked at 559 concussions suffered by NHL players in regular season games and was based on physicians' reports from every team in the league. They estimate the incidence of concussion was 1.8 per 1,000 player-hours.
Almost 70 per cent of the concussions studied were first concussions, 22 per cent were a second concussion and six per cent were a third concussion. The study found that the typical time loss in days increased by 2.25 times for every recurrent concussion a player experience.
In those concussions in which the time off was documented, 31 per cent of players lost more than 10 days of play.
The most common post-concussion symptom was headache, which was reported in 71 per cent of cases, followed by dizziness in 34 per cent, nausea in 24 per cent, neck pain in 23 per cent and blurred vision in 22 per cent.
Interestingly, loss of consciousness -- often considered a key red flag that signals a concussion -- occurred in only 18 per cent of cases.
The study results will be passed on to the NHL working group, which will examine ways to prevent concussions, and how to respond when they do happen.
