The GCS-Pupils (GCS-P) score extends the Glasgow Coma Scale (GCS) by incorporating pupil reactivity into a single index of early clinical severity in traumatic brain injury.

It was derived by Brennan, Murray and Teasdale using pooled individual-patient data for 15,900 patients from the CRASH and IMPACT traumatic brain injury datasets, with early GCS, bilateral pupil reactions and 6-month Glasgow Outcome Scale outcomes recorded.
In the pooled data, 6-month mortality fell from about 51% at GCS 3 to 3% at GCS 15, and rose from about 16% when both pupils reacted to 59% when neither reacted. Combining GCS and pupil reactivity into GCS-P (GCS minus a pupil reactivity score of 0–2) produced a smoother, more discriminative relationship between initial severity and both death and unfavourable outcome across scores 1–15, with mortality around 74% and unfavourable outcome about 90% at GCS-P 1.
Logistic models using GCS-P explained slightly more variation in 6-month mortality and unfavourable outcome than models using GCS alone, with performance close to more complex combinations of GCS and pupillary data.

External neurocritical care and severe traumatic brain injury ICU cohorts suggest that GCS-P discriminates in-hospital and 90-day mortality at least as well as, and often better than, GCS alone, and that it separates high-risk subgroups even among patients presenting with the same total GCS score.

GCS-P is most informative in moderate to severe adult traumatic brain injury and when combined with age and CT findings, for example via the related GCS-PA and GCS-PA CT prognostic charts. Evidence in paediatric populations and in non-traumatic causes of coma is more limited, so use the score alongside full neurological examination, imaging and local head injury pathways rather than as a stand-alone prognostic tool.

GCS-Pupils Score (Glasgow Coma Scale Pupils Score)