Critical Care
FOUR Score (Coma)
Full Outline of UnResponsiveness — coma severity.
Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.
Background
The FOUR (Full Outline of UnResponsiveness) score assesses consciousness in critically ill patients and was designed to overcome a key limitation of the Glasgow Coma Scale: it can be applied to intubated patients because it does not rely on a verbal response. It grades four components — Eye response, Motor response, Brainstem reflexes and Respiration — each from 0 to 4, giving a total out of 16. By including brainstem reflexes and respiratory pattern, it captures neurological detail relevant to coma and brain death that the GCS omits. It also helps detect locked-in syndrome and vegetative states through specific eye and motor responses.
Interpreting the result
Higher scores indicate better consciousness: 13–16 reflects mild impairment or near-normal consciousness, 9–12 moderate impairment and 0–8 severe impairment. A total of 0, with absent brainstem reflexes and respiration, carries the gravest prognosis. The four components should also be read individually, as a low brainstem or respiration sub-score signals critical deterioration even when the total seems intermediate. It is used serially to track trajectory rather than as a single snapshot.
Advice
Lower scores indicate worse consciousness. A FOUR score of 0 carries the gravest prognosis. Use alongside full clinical assessment.
Worked example
An intubated patient opens their eyes to loud voice (2), shows flexion to pain (2), has pupil and corneal reflexes present (4) and breathes above the ventilator rate (1): total = 2 + 2 + 4 + 1 = 9 out of 16, indicating moderate impairment of consciousness.
Pearls / pitfalls
- Its main advantage over the GCS is that it remains valid in intubated patients, where the GCS verbal score is lost.
- Always record the component scores, not just the total — brainstem and respiration sub-scores carry important prognostic and triage information.
- A FOUR score of 0 with absent brainstem reflexes prompts consideration of brain-death assessment, but the score itself does not diagnose brain death.
- Sedation, neuromuscular blockade and metabolic derangement confound the score, as they do the GCS; interpret in clinical context.
Evidence & validation
Developed and validated by Wijdicks and colleagues at the Mayo Clinic, the FOUR score has been shown to have good inter-rater reliability and to predict in-hospital mortality and outcome, and is widely used in neurocritical and general intensive care.
Frequently asked questions
Why use the FOUR score instead of the GCS?
The FOUR score can be applied to intubated patients because it has no verbal component, and it adds brainstem reflexes and respiratory pattern. This gives more neurological detail in critically ill or comatose patients.
What is the range of the FOUR score?
It runs from 0 to 16, with four components (eye, motor, brainstem, respiration) each scored 0 to 4. Higher totals indicate better consciousness.
What does a FOUR score of 0 mean?
It indicates the most severe impairment, with no eye or motor response, absent brainstem reflexes and apnoea or breathing only at the ventilator rate. This carries the worst prognosis and may prompt brain-death evaluation.
Can the FOUR score detect locked-in syndrome?
Yes. The eye sub-score rewards tracking and blinking to command, which can reveal preserved awareness in a patient who otherwise appears unresponsive, helping distinguish locked-in syndrome.
Does the FOUR score replace clinical examination?
No. It standardises and communicates the level of consciousness but should accompany a full neurological assessment and consideration of confounders such as sedation and metabolic derangement.
References
- Wijdicks EFM, Bamlet WR, Maramattom BV, et al. Validation of a new coma scale: the FOUR score. Ann Neurol. 2005;58(4):585–593.
- Wijdicks EFM, Kramer AA, Rohs T, et al. Comparison of the FOUR score and the Glasgow Coma Scale in predicting outcome in comatose patients. Neurocrit Care. 2015.
About the creator
Wijdicks EF et al.
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