Bedside Concussion Assessment and CT Criteria
For bedside concussion assessment in adults ≥16 years, use the Glasgow Coma Scale (GCS) as your primary tool, then apply the 2008 ACEP Clinical Policy criteria to determine who needs emergent non-contrast head CT based on whether loss of consciousness (LOC) or post-traumatic amnesia (PTA) occurred.
Initial Bedside Assessment
Start with the GCS score to stratify severity:
- GCS 14-15: Mild traumatic brain injury (mTBI) - proceed with clinical decision rules below
- GCS 9-12: Moderate injury - CT indicated
- GCS 3-8: Severe injury - CT indicated
For patients with GCS 14-15, your next step depends on whether LOC or PTA occurred.
CT Criteria: Patients WITH LOC or PTA (Level A - Strongest Evidence)
Order emergent non-contrast head CT if ANY of the following are present 1, 2:
- Headache
- Vomiting
- Age >60 years
- Drug or alcohol intoxication
- Short-term memory deficits
- Physical evidence of trauma above the clavicle
- Post-traumatic seizure
- GCS <15
- Focal neurologic deficit
- Coagulopathy (including warfarin, anticoagulants, or bleeding diathesis)
This approach uses the highly sensitive New Orleans Criteria (97.7-99.4% sensitivity for any traumatic CT finding) 2.
CT Criteria: Patients WITHOUT LOC or PTA (Level B - Strong Evidence)
Consider emergent non-contrast head CT if ANY of the following are present 1, 2:
- Focal neurologic deficit
- Vomiting
- Severe headache
- Age ≥65 years
- Physical signs of basilar skull fracture
- GCS <15
- Coagulopathy
- Dangerous mechanism of injury: ejection from motor vehicle, pedestrian struck by vehicle, fall from >3 feet or >5 stairs
This approach uses the more specific Canadian CT Head Rule criteria (83.4-87.2% sensitivity for neurosurgical lesions, but 37.2-39.7% specificity, reducing unnecessary imaging) 2.
Key Clinical Pearls
The 2021 ACR Appropriateness Criteria endorses this 2008 ACEP approach as a balanced strategy for clinicians not committed to a single decision rule 2. Both the New Orleans Criteria and Canadian CT Head Rule have been validated as essentially 100% sensitive for detecting injuries requiring neurosurgical intervention 2.
Common Pitfalls to Avoid:
Coagulopathy threshold: Most guidelines recommend CT for ANY coagulopathy, though controversy exists for antiplatelet therapy alone in minimal trauma 2. When in doubt with anticoagulation, image.
Age cutoffs differ: Note >60 years for patients WITH LOC/PTA versus ≥65 years for those WITHOUT 1, 2.
Don't use skull radiographs - they've been replaced by CT, which is far more sensitive for neurosurgical lesions 2.
Exclude from these rules: Patients <16 years old, penetrating trauma, multisystem trauma, or GCS <14 on initial ED evaluation 1.
Additional Considerations:
Recent validation studies confirm these criteria maintain excellent sensitivity. A 2016 Spanish study showed both CCHR and New Orleans Criteria achieved 100% sensitivity for significant CT lesions and neurosurgical intervention, with CCHR demonstrating better specificity (25.3% vs lower for New Orleans) 3. A 2024 Japanese study of 1,688 MHI patients found a negative predictive value of 99.78% when risk factors were absent 4.
If the patient meets NONE of the above criteria, emergent CT is not indicated - these patients can be safely discharged with appropriate head injury precautions and return instructions 1, 2.