There are currently three approaches to determining the severity of sports-related concussions.
Grading the concussion at the time of injury. This is the approach taken by the 1991 Colorado Medical Society (CMS) and 1997 American Academy of Neurologists (AAN) concussion grading scales. Both emphasize loss of consciousness (LOC) and post-traumatic amnesia (PTA) over other post-concussion symptoms.
Grade the concussion based on the presence and duration of symptoms. This is the approach taken by MomsTeam expert, Robert C. Cantu, M.D., in his revised (2001) Cantu Evidence-Based Grading Scale. The Cantu concussion grading scale and guidelines place less weight on LOC as a potential predictor of subsequent impairment and additional weight on the overall persistence of post-concussion symptoms and grade the injury only after the athlete is symptom-free.
- Eliminate grading to focus on whether the athlete is symptomatic or symptom free. The 2nd International Conference on Concussion in Sport held in Prague in 2004 (Prague consensus statement) introduced a third approach to the grading scale dilemma by simply eliminating the use of a grading scale. Like Dr. Cantu's revised guidelines, the Prague consensus statement focuses on whether the athlete is symptomatic or symptom free and determines severity retrospectively, after all post-concussion signs and symptoms have cleared, the neurological exam is normal, and cognitive function has returned to pre-injury level (e.g. baseline). It classifies concussions as either simple or complex depending on how long it takes for all concussion signs to clear.
For a comparison of the CMS, AAN and Cantu Evidence-Based Grading Scale, click here.