April 18, 2011
More Game Time Lost By NHL Players With Recurrent Concussion
A new study of concussions over seven NHL (National Hockey League) seasons indicates that rates of concussions have declined from a peak in 2000, although the time lag between injury and return to play has increased, states an article in the CMAJ (Canadian Medical Association Journal) (pre-embargo link only) http://www.cmaj.ca/embargo/cmaj092190.pdf.
Concussions are caused by traumatic force. While concussion symptoms resolve over time once injuries are identified and appropriately managed, they can be career-ending for athletes who return to play too soon after their injuries. In the United States it is estimated that roughly 1.6 to 3.8 million sports- and recreation-related brain injuries take place each year.
In this large study, physicians from the NHL looked at data on 559 regular season game concussions from 1997-2004. The estimated incidence was 1.8 concussions per 1,000 player-hours. The postconcussion symptom reported most often was headache (71%), followed by dizziness (34%), nausea (24%), neck pain (23%), low energy/fatigue (22%), blurred vision (22%), amnesia (21%), and loss of consciousness (18%). Typical time loss in days increased 2.25 times during the study period for every recurrent concussion.
The researchers found several clinical signs/symptoms that predicted players being off the ice for more time. Headache, low energy or fatigue, memory loss, and abnormal neurological exam were significant predictors of time loss for players with concussions.
"Our results suggest that more should be done to educate all involved with the sport about the potential adverse effects associated with continuing to play while symptomatic, failing to report symptoms to medical staff and failure to recognize or evaluate any suspected concussion," writes author Dr. Brian Benson, Faculty of Kinesiology, University of Calgary with coauthors.
NHL regular season game concussion rates decreased from a peak of 7.7 concussions per 100 players during the 2000-2001 season to 4.9 per 100 players in 2003-2004.
"The findings also suggest that more conservative or precautionary measures should be taken in the immediate postconcussion period, particularly when an athlete reports/experiences a postconcussion headache, low energy/fatigue, amnesia, recurrent concussion, many different postconcussion symptoms, or has an abnormal neurologic exam," conclude the authors.
In a related commentary http://www.cmaj.ca/embargo/cmaj110504.pdf, Dr. Peter Sojka, Mid Sweden University, Ostersund, Sweden, writes about the distinction between sport and non-sport concussions and the need for researchers studying these injuries to exchange ideas to enhance understanding of how to treat.
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