Historically, concussions were "graded." The three most commonly used concussion grading systems were the Cantu,1 Colorado Medical Society (CMS),2 and the American Academy of Neurology (AAN)3 guidelines.4 
The CMS and AAN measured concussion severity and assigned a "grade" to the concussion at the time of injury. Both emphasized loss of consciousness(LOC) and post-traumatic amnesia (PTA) over other post-concussionsymptoms.
The Cantu Grading System, developed by MomsTeam concussion expert emeritus, Robert C. Cantu, M.D., placed less weight on LOC as a potential predictor of subsequent impairment and additional weight on the overall persistence of post-concussion symptoms, assigning a grade to the injury only after the athlete is symptom-free.
Here's how the three concussion grading scales compared:
| Concussion Grade | Cantu Grading System (2001 Revision) | 1991 Colorado Medical Society Guidelines | 1997 American Academy of Neurology (AAN) Guidelines |
|---|---|---|---|
| Grade 1 (mild) |
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| Grade 2 (moderate) |
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| Grade 3 (severe) |
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No same-day return to play
Historically, LOC was thought to be a hallmark of a more serious, severe concussion, with athletes who lost consciousness at the time of their concussion receiving a higher "grade" under these grading systems than those that did not, and athletes who were knocked unconscious for longer periods of time receiving higher grades than those who were unconscious for shorter periods of time. These grades were used to determine how long an athlete should be removed from sports after sustaining a concussion.Ten years ago, young athletes who suffered what the old grading scales would have considered "mild" or Grade 1 concussions would have been routinely allowed return to sports in as little as 15- (Cantu) to 30-minutes (AAN) after his or her symptoms were thought to have cleared.
Individualized concussion assessment
Extensive research on sport-related concussion since 1999, however, has provided medical professionals with a much better understanding of the symptomatic course and risk of potential long-term complications, even death, from allowing a youth athlete to return before his concussion has been fully evaluated away from the sports sideline.
Clinicians involved in the assessment and management of sport-related concussions began to notice that athletes who were knocked unconscious for brief periods of time often recovered more quickly than those who did not lose consciousness at all. Therefore, it seemed inaccurate to diagnose those who did not lose consciousness with a lower grade of concussion. Furthermore, grades were used to determine the period of time that an athlete was removed from sports. It did not make sense to keep those who recovered more quickly out of sports for longer periods of time than those who recovered more slowly.
For this and for several other reasons, the use of these grading systems has been abandoned in favor of a symptom-based approach to individually guide return to play decisions.
Nowadays, when making decisions to return an athlete back to play after he or she has recovered from a sport-related concusion, doctors consider each case individually, taking all factors into consideration in helping to determine the amount of time an athlete is asked to remain symptom free before returning to contact, with recent international consensus statementsprolonged LOC and anterograde amnesia as red flags for concussion and factors that may modify concussion management.
The universal trend has thus been strongly against alllowing to return to the same game or practice no matter how quickly their symptoms appear to clear and in favor of a conservative and gradual return of an athlete to sports only when symptoms have cleared not only at rest but with exertion and his her neurocognitive function has returned to its pre-injury baseline. The no same-day-return-to-play rule and exercise-limited return to play protocol are now reflected in laws enacted in a growing number of states (totaling 28 as of October 7, 2011).
Grading systems had value
"While grading systems have been abandoned in favor of more individualized management," writes Dr. William P. Meehan III, MomsTeam concussion expert and Director of the Sport Concussion Clinic at Children's Hospital Boston in his 2011 book, Kids, Sports, and Concussion,7 "they were extremely beneficial during their time. When the first grading systems were developed," he notes, "few medical professionals took concussions seriously. Athletes were often sent straight back into play after sustaining a concussion, without another thought." Thus, Dr. Meehan writes, "these grading systems were instrumental in drawing much need attention to the issue of concussive brain injury in sports. They allowed many athletes to recover from their injuries, prior to sustaining an additional concussion."
For the most comprehensive, up-to-date concussion information on the Internet, click here.
1. Cantu RC. Posttraumatic retrograde and anterograde amnesia, pathophysiology and implications in grading and safe return to play. J Athl Train. 2001;36(1):244-248.
2. Colorado Medical Society. Report of the Sports Medicine Committee: Guidelines for the Management of Concussions in Sport (Revised). Denver, CO: Colorado Medical Society; 1991.
3. American Academy of Neurology. Practice parameter: the management of concussion in sports (summary statement). Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 1997;48(3):581-585.
4. Halstead, M, Walter, K. "Clinical Report - Sport-Related Concussion in Children and Adolescents" Pediatrics. 2010;126(3):597-615.
5. McCrory P, Johnston K, Meeuwisse W, et al. Summary and agreement statement of the 2nd International Conference on Concussion in Sport, Prague 2004. Br J. Sports Med. 2005;39(4):196-2004.
6. McCrory P, Meeuwisse W, Johnston K. et al. Consensus statement on Concussion in Sport 3rd International Conference on Concussion in Sport held in Zurich, November 2008. Br. J. Sports Med. 20090: 43:i76-i84.
7. Meehan WP. Kids, Sports, and Concussion (Praeger 2011) at 26.
Updated and revised July 25, 2011
