Current Approach to Concussion Grading
The traditional concussion grading scales have been abandoned in favor of a symptom-based approach for determining concussion severity and guiding return-to-play decisions. 1
Historical Grading Systems
Historically, there were more than 25 different published grading systems for concussions. The three most commonly used were:
- American Academy of Neurology grading scale
- Colorado Medical Society grading scale
- Cantu grading scale 1
These traditional grading systems were developed through expert opinion and relied heavily on:
- Loss of consciousness (LOC)
- Confusion
- Amnesia
They were used to determine concussion severity and subsequent return-to-play decisions. However, these systems lacked scientific validation and empirical support 2, 3.
Current Consensus on Concussion Assessment
The Concussion in Sport Group (CISG) has recommended abandoning the use of grading scales for several key reasons:
- Loss of consciousness occurs in less than 10% of concussions but was heavily weighted in old grading systems 1
- Research has shown that LOC, while useful as an indicator of initial injury severity, does not correlate well with other indices of concussion severity, including symptom duration 2
- The arbitrary nature of grading scales doesn't account for the complex and individualized nature of concussion recovery 1
Modern Approach to Concussion Assessment
The current recommendation is a symptom-based approach that uses several evaluation measures to guide management and return-to-play decisions 1. This approach includes:
Comprehensive symptom assessment: Using standardized tools like the Scale of Postconcussion Symptoms 1 that evaluate symptoms across physical, cognitive, emotional, and sleep categories
Neurocognitive testing: Objective assessment of cognitive function, which has been shown to correlate with symptom duration 2, 4
Monitoring symptom evolution: Tracking the number, severity, and duration of symptoms over time 5
Individualized return-to-activity protocols: Following a stepwise progression based on symptom resolution rather than arbitrary time periods 6
Factors Associated with Concussion Severity
Research has identified several factors that may be more predictive of concussion severity than traditional grading systems:
- Self-reported memory problems 24 hours post-concussion are robust indicators of concussion severity 2
- Decline on neurocognitive testing correlates significantly with longer symptom duration 2
- Continued participation after concussion is associated with higher symptom severity and longer recovery times 7
- Female athletes, those with migraine history, and those with prior concussions may experience more severe outcomes when continuing to play after concussion 7
Clinical Implications
When assessing concussion severity, clinicians should:
- Focus on the number, type, and duration of symptoms rather than arbitrary grading
- Pay particular attention to cognitive symptoms, which may be more characteristic of delayed symptom resolution 5
- Use standardized assessment tools to objectively measure symptoms and cognitive function
- Consider risk factors such as sex, concussion history, and continued participation after injury
- Implement a gradual, symptom-limited return to activity protocol
Common Pitfalls to Avoid
- Relying solely on loss of consciousness to determine concussion severity
- Using outdated grading systems that lack empirical support
- Failing to perform follow-up assessments to monitor symptom resolution
- Allowing premature return to play based on arbitrary timelines rather than symptom resolution
- Overlooking the importance of cognitive symptoms in predicting recovery
By focusing on symptom assessment and resolution rather than arbitrary grading scales, clinicians can better manage concussions and optimize outcomes for patients.