by Stacey Chamberlain
A 36-year-old woman slipped on ice and fell and hit her head. She reports loss of consciousness for a minute after the event, witnessed by a bystander. She denies headache. She denies weakness, numbness or tingling in her extremities and no changes in vision or speech. She has not vomited. She remembers the event except for the transient loss of consciousness. She doesn’t use any blood thinners. On physical exam, she has a GCS of 15, no palpable skull fracture and no signs of a basilar skull fracture.
Should you get a CT head for this patient to rule out a clinically significant brain injury?
Canadian CT Head Rule
High-Risk Criteria (rules out the need for neurosurgical intervention)
Medium Risk Criteria (rules out clinically important brain injury)
- GCS < 15 at two hours post-injury
- Suspected open or depressed skull fracture
- Any sign of basilar skull fracture (hemotympanum, Raccoon eyes, Battle’s sign, CSF oto or rhinorrhea)
- Retrograde amnesia to event ≥ 30 minutes
- Dangerous mechanism (pedestrian struck by motor vehicle, ejection from the motor vehicle, fall from > 3 feet or > 5 stairs)
The Canadian CT Head Rule (CCHR) only applies to patients with an initial GCS of 13-15, witnessed loss of consciousness (LOC), amnesia to the head injury event, or confusion. The study was only for patients > 16 years of age. Patients were excluded from the study if they had “minor head injuries” that didn’t even meet these criteria. Patients were also excluded if they had signs or symptoms of moderate or severe head injury including GCS < 13, post-traumatic seizure, focal neurologic deficits, or coagulopathy. Other studies have looked at different CDRs for traumatic brain injury including the New Orleans Criteria (NOC). However, CCHR has been found to have superior sensitivity and specificity.
By applying this rule to the above case, the patient should be considered for imaging due to the mechanism. A fall from standing for an adult patient would constitute a fall from > 3 feet; therefore, although the patient would not likely be high risk and need neurosurgical intervention, the patient might have a positive finding on CT that in many practice settings would warrant an observation admission.