emergency-medicine neurology neurosurgery

CT Head Rules — Adults (NICE NG232)

NICE NG232 (2023) criteria for CT head imaging after a head injury in people aged 16 and over. For under-16s use the NICE under-16 criteria, PECARN, CATCH or CHALICE.

Used in: Head Injury

GCS 12 or less on initial assessment in the emergency department*

GCS less than 15 at 2 hours after the injury (on assessment in the emergency department)*

Suspected open or depressed skull fracture, or any sign of basal skull fracture (haemotympanum, 'panda' eyes, CSF leak from the ear or nose, Battle's sign)*

Post-traumatic seizure*

Focal neurological deficit*

More than 1 episode of vomiting*

Any loss of consciousness or amnesia since the injury*

Age 65 or over*

Current bleeding or clotting disorder*

Dangerous mechanism: pedestrian or cyclist struck by a motor vehicle, occupant ejected from a motor vehicle, or fall from more than 1 m or 5 stairs*

More than 30 minutes' retrograde amnesia of events immediately before the injury*

Anticoagulant (vitamin K antagonist, DOAC, heparin or LMWH) or antiplatelet treatment other than aspirin alone*

Score interpretation

No NICE CT Head Criterion Met 0

None of the NICE NG232 CT criteria for people aged 16 and over is present.

→ Clinical judgement on observation; if discharged, give verbal and written head-injury advice with return precautions (worsening headache, vomiting, drowsiness, confusion, seizure, limb weakness).

Consider CT Head Within 8 Hours 1

Anticoagulant or antiplatelet treatment (not aspirin alone) and no other CT indication (NICE NG232 1.5.13).

→ Consider CT within 8 hours of the injury (for example if risk assessment is difficult or the person may not return if they deteriorate), or within 1 hour if presenting more than 8 hours after the injury.

CT Head Within 8 Hours 2

Loss of consciousness or amnesia with age ≥ 65, a bleeding or clotting disorder, a dangerous mechanism or > 30 minutes' retrograde amnesia (NICE NG232 1.5.9).

→ CT within 8 hours of the injury, or within 1 hour if presenting more than 8 hours after it; scan sooner if a 1-hour risk factor develops.

CT Head Within 1 Hour 3

At least one NICE NG232 1.5.8 risk factor.

→ CT within 1 hour of the risk factor being identified, with a provisional written report within 1 hour; discuss significant findings with neurosurgery; reverse anticoagulation if there is intracranial bleeding.

Interpretation bands for the CT Head Rules. Apply clinical judgement and local guidance.

References

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Pathways

📚 MRCEM Revision

Featured in these MRCEM clinical pathways

The CT Head Rules is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.

Head Injury

MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.

Score interpretation

References

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