When should a patient with a concussion and neck pain undergo a computed tomography (CT) scan of the head and neck?

When to Obtain CT Imaging in Concussion with Neck Pain

A patient with concussion and neck pain should undergo immediate non-contrast CT of the head if they have ANY of the following high-risk features: loss of consciousness, post-traumatic amnesia, GCS <15, focal neurologic deficit, vomiting, severe headache, anticoagulation/antiplatelet therapy (excluding aspirin monotherapy), age ≥60-65 years, or signs of skull base fracture. 1, 2, 3

Head CT Indications

Immediate CT is Required for ANY of These Features:

• Glasgow Coma Scale (GCS) score <15 at any point after injury 1, 3
• Loss of consciousness of any duration 2, 3
• Post-traumatic amnesia (>30 minutes before impact is particularly high-risk) 2, 3
• Focal neurologic deficits on examination 1, 3
• Vomiting (≥2 episodes increases risk significantly) 1, 2, 3
• Severe or persistent headache 1, 2, 3
• Physical evidence of trauma above the clavicles (including signs of basilar skull fracture) 2, 3
• Post-traumatic seizure 2, 3

Anticoagulation Status is Critical:

• Warfarin increases intracranial injury risk 1.88-fold and mandates CT imaging regardless of symptom severity 2
• Dual antiplatelet therapy (aspirin + clopidogrel) increases risk 2.88-fold and requires CT 2
• Novel oral anticoagulants (NOACs) carry lower but still significant hemorrhage risk (2.6% vs 10.2% for warfarin) and warrant imaging 2
• Aspirin monotherapy alone does NOT significantly increase risk (RR 1.29, not statistically significant) and is not an absolute indication for CT 2
• Clopidogrel or other antiplatelet agents require CT imaging 2, 3

Age-Related Considerations:

• Age ≥60-65 years is itself a high-risk criterion that warrants head CT when combined with ANY other risk factor 2, 3
• Elderly patients (>60 years) with GCS 15 and amnesia had 10% positive CT rate, with some requiring neurosurgical intervention 2
• Age >60 years had an odds ratio of 19.2 for intracranial injury even in patients with GCS 14-15 2

Neck/Cervical Spine Imaging Considerations

When to Add Vascular Imaging (CTA Head and Neck):

CTA of the head and neck should be obtained if there is suspicion of traumatic vascular injury, particularly:

• Neck pain with neurologic symptoms suggesting vertebral artery dissection 1
• Skull base fractures involving the carotid canal 1
• Cervical spine fractures (especially transverse foramen involvement) 1
• Unexplained neurologic deficits not accounted for by initial CT findings 1
• Penetrating head/neck trauma 1

CTA has 97.7% sensitivity and 100% specificity for vascular injury detection and is the preferred initial study over catheter angiography 1. CTA of both head AND neck is superior to either alone for assessing the full extent of vertebral artery dissection 1.

Timing of CT Imaging

• Do not delay CT if high-risk features are present 2
• Optimal detection of lesions occurs when CT is performed ≥5 hours post-trauma, but this should not delay imaging in symptomatic patients 2
• CT is highly sensitive for detecting findings requiring neurosurgical intervention in the acute phase 1

Follow-Up Imaging

Repeat CT Indications:

• If initial CT shows intracranial hemorrhage in anticoagulated patients, repeat imaging is indicated as these patients have 3-fold increased risk of hemorrhage progression (26% vs 9%) 2
• Neurologic deterioration after initially normal or stable CT 1
• Failure to achieve GCS 15 after 24 hours despite normal initial CT 1

When Repeat CT May NOT Be Necessary:

• Patients with normal initial CT and stable neurologic examination have very low risk of deterioration (0.006%) 1
• In clinically stable patients with positive initial CT, control scan can be safely delayed up to 48 hours 4

When CT is NOT Required

CT can be safely deferred if ALL of the following are true:

• No loss of consciousness 3
• No post-traumatic amnesia 3
• GCS = 15 and stable 2, 3
• No focal neurologic deficits 3
• No vomiting or severe headache 3
• Not on anticoagulation (except aspirin monotherapy) 2, 3
• Age <60 years OR age ≥60 without other risk factors 2, 3
• Reliable caregiver available for close observation 2

Critical caveat: Even with these criteria met, provide clear written and verbal discharge instructions about warning signs (worsening headache, vomiting, confusion, altered consciousness) and ensure reliable follow-up 2.

Role of MRI

• MRI is NOT indicated for initial evaluation of acute head trauma 1
• MRI is more sensitive than CT for detecting posterior fossa lesions, diffuse axonal injury, small contusions, and cerebellar infarcts from vertebral dissection 1, 5
• Consider MRI when: initial CT is normal but persistent neurologic findings remain, or in subacute/chronic phase for better characterization of injury 5, 6
• MRA head and neck may be useful for problem-solving after inconclusive CTA for suspected vascular injury 1