GCS-Pupils Score (GCS-P)

How the score works

The pupil reactivity score reflects the number of pupils that do not react to light: 2 if both pupils are unreactive, 1 if only one is unreactive and 0 if neither is. The GCS-P is the GCS total minus the pupil reactivity score, so it ranges from 1 to 15 (Wang 2022). A 2025 NINDS working group report describes the same rule: a patient with a GCS of 3 and one unreactive pupil scores 2, and with both pupils unreactive scores 1 (Menon 2025). The score was first described by Brennan and colleagues (Brennan 2018).

For example, a GCS of 8 with one unreactive pupil gives a GCS-P of 7. A GCS of 6 with both pupils unreactive gives a GCS-P of 4.

What studies found

In 192 patients with traumatic brain injury admitted to an intensive care unit, with the Glasgow Outcome Scale after discharge as the outcome, the area under the curve (AUC) was 0.812 (95% CI 0.765 to 0.858) for the GCS-P (Wang 2022). In that study, adding arterial lactate to the GCS-P gave a higher AUC of 0.866 (0.827 to 0.904) (Wang 2022).

Limits of a combined score

The 2025 NINDS working group notes that the GCS-P gives more prognostic information than the GCS alone, but only about half of the gain from adding the pupil responses as separate items. It also notes that above a GCS of 3 a single total cannot show whether points were lost for the pupils or for another GCS item. The group recommends assessing and recording pupil responses to light, with automated pupillometry if possible, but recording them separately from the GCS rather than as a combined GCS-P (Menon 2025).

Related tools

To work out the GCS total, use the Glasgow Coma Scale calculator. For a coma scale that also scores brainstem reflexes and breathing, see the FOUR score. To grade the admission head CT, see the Rotterdam CT score, the Helsinki CT score or the Marshall CT classification. To grade outcome after a brain injury, see the Glasgow Outcome Scale. Other bedside scores are listed under For healthcare professionals.