What are the guidelines for ordering a computed tomography (CT) scan after a fall?

Guidelines for CT Scan After Falls

CT scans after falls should be performed for patients with any of the following: focal neurologic deficits, anticoagulation therapy, altered mental status, signs of elevated intracranial pressure, or significant deterioration of consciousness. 1

Indications for Head CT After Falls

High-Risk Criteria (CT Recommended)

• Focal neurological deficits or signs suggesting intracranial injury 1
• Anticoagulation therapy (regardless of neurological symptoms) 2
• Altered mental status or decreased level of consciousness (GCS <15) 1, 3
• Signs of elevated intracranial pressure (severe headache, vomiting, visual disturbances) 1
• Age >60 years with any of: headache, vomiting, drug/alcohol intoxication, short-term memory deficits, physical trauma above clavicle, seizure, or coagulopathy 1, 3
• Loss of consciousness or post-traumatic amnesia 3, 1
• Signs of basilar skull fracture 3, 4
• Male sex (associated with higher risk of traumatic lesions) 5
• Past history of post-traumatic brain injury 5

Clinical Decision Rules

Canadian CT Head Rule

• More specific than New Orleans Criteria - can reduce CT scans by 37% while maintaining high sensitivity 3, 1
• Recommends CT for patients with:
  • GCS <15 at 2 hours post-injury
  • Suspected open or depressed skull fracture
  • Signs of basilar skull fracture
  • Vomiting ≥2 episodes
  • Age ≥65 years
  • Amnesia >30 minutes before impact
  • Dangerous mechanism of injury 3, 1

New Orleans Criteria

• More sensitive but less specific than Canadian CT Head Rule 3, 1
• Recommends CT for patients with any of:
  • Headache
  • Vomiting
  • Age >60 years
  • Drug or alcohol intoxication
  • Persistent anterograde amnesia
  • Visible trauma above clavicle
  • Seizure 3, 1

Florida Geriatric Head Trauma CT Clinical Decision Rule

• Specifically validated for patients ≥65 years old 4
• Point system with CT indicated for score ≥25:
  • Arrival via EMS (+30 points)
  • GCS <15 (+20 points)
  • GCS <14 (+50 points)
  • Antiplatelet medications (+17 points)
  • Loss of consciousness (+16 points)
  • Signs of basilar skull fracture (+50 points)
  • Headache (+20 points) 4

Special Considerations

Anticoagulated Patients

• All patients on anticoagulants with head trauma should receive CT scan regardless of symptoms 2
• Higher risk of intracranial hemorrhage (3.9%) compared to non-anticoagulated patients (1.5%) 2
• Direct oral anticoagulants (DOACs) have lower incidence of intracranial hemorrhage (2.6%) than vitamin K antagonists (10.2%) but still higher than non-anticoagulated patients 2

Timing Considerations

• Optimal detection of lesions occurs when CT is performed within 5 hours of trauma 5
• Patients presenting >12 hours after injury with symptoms have significant risk of abnormal head CT 6

Elderly-Specific Considerations

• Age ≥60 years is an independent risk factor for intracranial injury 1, 7
• Presence of vomiting in elderly patients significantly increases risk of traumatic lesions 5, 7
• Combination of symptoms in elderly patients increases risk of abnormal CT findings 6

When CT Is Not Necessary

• Fall without loss of consciousness, no impact to head, and normal neurological examination 1
• Absence of anticoagulant therapy and no headache or vomiting 1
• Patients who don't meet any criteria from established clinical decision rules 3, 1

Follow-up Imaging

• MRI is more sensitive for all post-traumatic lesions other than skull fracture and subarachnoid hemorrhage 8
• If CT does not demonstrate pathology adequate to account for clinical state, MRI is warranted 8
• Follow-up imaging is best done with MRI as it is more sensitive to parenchymal changes than CT 8