Severity of Concussions in Athletes
Grading Concussions is no Longer Accepted Standard of Care
Jun 19, 2009
Historically, medical professionals were asked to “grade” the severity of an athlete’s concussion based on specific symptoms including loss of consciousness and retrograde amnesia. However, there were over 35 grading scales in the literature and no consensus among them.
Historical Concussion Grading Scales
Many of the original grading scales were based on the length of time for specific symptoms. For example, an athlete with no loss of consciousness was diagnosed with a "first degree" concussion. An athlete who lost consciousness for less than two minutes was diagnosed with a "second degree" concussion while an athlete who had lost consciousness for greater than two minutes was diagnosed with a "third degree" concussion.
The problem with these types of grading scales (besides no consensus) was that there was no significant correlation between symptoms at the onset of the injury and the duration and severity of symptoms.
Over the years, experts have shifted from “grading scales” to diagnosing the severity of the concussion based on the duration of the symptoms from the onset of the injury . Robert Cantu designed an evidenced-based grading scale based on the length that the symptoms lasted rather than on the initial onset of symptoms (Journal of Athletic Training, 2001).
In other words, Cantu's scale was based on how long the athlete suffered from concussion-type symptoms. The paradigm shift was significant in that athletes were not diagnosed at the time of injury, but rather after several weeks when the symptoms finally subsided.
A range of experts were invited to attend 3rd International Conference on Concussion in Sport held in Zurich in November, 2008. One of the goals of the conference was to address injury grading systems as well as build on the recommendations developed following the 1st (Vienna) and 2nd (Prague) International symposia on concussion.
Defining Concussion
The experts further defined concussion as a “complex pathophysiological process affecting the brain” induced by external forces (Journal of Science and Medicine in Sport, May, 2009). They further defined a concussive injury as including the following components:
- Caused by a direct blow or a force transmitted to the head
- Resulted in rapid onset of short-lived impairment of neurological function that resolves spontaneously
- Injury resulted in a functional disturbance rather than a structural injury to the brain
- Resulted in a set of clinical symptoms that may or may not include loss of consciousness.
- Resolution of symptoms followed a sequential course, but may be prolonged.
- No brain abnormality seen in neuroimaging studies (CT scans, MRIs and x-rays are normal)
New Categories of Concussion Symptoms
There was consensus from the experts to move from a “grading” scale to treating an athlete based on the current symptoms. Symptoms may occur in the following domains:
- Physical (i.e., loss of consciousness, amnesia)
- Behavioral changes (i.e., irritability)
- Somatic (i.e., headache)/Cognitive (i.e., feeling like in a fog) symptoms
- Sleep disturbances (i.e., drowsiness)
- Cognitive impairment (i.e., slowed reaction time)
According to the experts, if any of the above symptoms are present, a concussion should be suspected and appropriate treatment and management strategies should be put into place.
If an athlete is suspected of having a concussion, the athlete should be immediately evaluated on the sidelines by a medical professional (certified athletic trainer, team physician). If one of these medical professionals is not available, the athlete needs to be referred to a medical facility for appropriate evaluation and treatment.
Another significant recommendation that came out of this symposium was that any athlete suspected of a concussion should not be allowed to return to play on the day of the injury. This is a conservative approach based on protecting the athlete from further injury to his/her brain.
