Neuro emergencies

Approach to coma (GCS and FOUR score)

Reviewed Nov 2026·1 references
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Stabilise ABC and glucose first, then look for the pattern: structural (focal signs, asymmetric pupils) vs metabolic/toxic (symmetric, reactive pupils). Record GCS components and the FOUR score in intubated patients; image early and treat reversible causes.

At the bedside

Timed steps
  1. 1

    Stabilise

    0 min

    Airway (GCS ≤ 8 usually needs protection), breathing, circulation; glucose; thiamine 200-500 mg IV if malnourished/alcohol before dextrose; naloxone if opioid toxidrome.

  2. 2

    Pattern

    Examine

    Pupils (pinpoint = opioid, OP poisoning, pontine; fixed dilated unilateral = herniation), eye movements, motor asymmetry, neck stiffness, rash, eschar (scrub typhus), bite marks.

  3. 3

    GCS + FOUR

    Score

    GCS as E V M components. FOUR (Eye, Motor, Brainstem, Respiration; each 0-4) works in intubated patients and detects locked-in and brainstem signs.

  4. 4

    Bloods + CT

    Investigate

    Na+, Ca2+, glucose, urea, LFT/ammonia, ABG/CO2, CO-Hb, toxicology, malaria smear/RDT, blood cultures; CT head; LP after CT if infection suspected; EEG for non-convulsive status; MRI later.

  5. 5

    Reversible causes

    Treat

    Hypoglycaemia, hyponatraemia, hypercapnia, infection (empirical antibiotics/acyclovir), raised ICP (head up 30°, osmotherapy), poisons (antidotes), seizures.

FOUR score

Component43210
EyeEyelids open, tracks or blinks to commandOpen, not trackingClosed, open to loud voiceClosed, open to painRemain closed to pain
MotorThumbs-up, fist or peace signLocalises to painFlexion to painExtension to painNo response or myoclonus status
BrainstemPupil and corneal reflexes presentOne pupil wide and fixedPupil or corneal reflexes absentPupil and corneal reflexes absentPupil, corneal and cough reflexes absent
RespirationNot intubated, regularNot intubated, Cheyne-StokesNot intubated, irregularBreathes above ventilator rateBreathes at ventilator rate or apnoea

Total 0-16. Lower scores are worse; 0 with apnoea prompts brain death evaluation.

Red flag · call your senior now
Unilateral fixed dilated pupil with falling GCS: herniation; osmotherapy and urgent neurosurgical review.
Pitfall
Reporting a single GCS total without components (e.g. 'GCS 8' hides M5 vs M2).
Pitfall
Assuming alcohol intoxication explains coma (head injury, hypoglycaemia, methanol).
Pearl
Metabolic coma usually spares pupillary reflexes; structural coma often does not.

Calculators for this topic

Glasgow Coma Scale

Eye + Verbal + Motor (3-15). Record components, e.g. E3 V4 M5.

References

  1. 1

    Wijdicks EFM, Bamlet WR, Maramattom BV, Manno EM, McClelland RL. Validation of a new coma scale: the FOUR score. Ann Neurol. 2005;58(4):585-593

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