The Cardiovascular
ToolsCalculators

GCS-Pupils (GCS-P) Score

Glasgow Coma Scale combined with pupil reactivity for an extended index of TBI severity.

GCS-Pupils (GCS-P) Score
Eye opening (E)
Verbal response (V)
Motor response (M)
Pupil reactivity
Number of pupils unreactive to light.
Result15 points

GCS-P 15 falls in a range that roughly corresponds to mild-severity injury on the conventional GCS scale; lower GCS-P values track with progressively higher mortality and worse functional outcome after traumatic brain injury. The original derivation study treats GCS-P as a continuous severity/prognostic index rather than a formally defined categorical cutoff.

Glasgow Coma Scale (E+V+M)
15
Pupil reactivity score
0
GCS-Pupils score
15

When to use

  • Grading severity and estimating prognosis after traumatic brain injury alongside or instead of the GCS alone.
  • Communicating combined consciousness and brainstem (pupillary) findings in a single ordinal score for trials or handover.

Formula

GCS-P = GCS (Eye + Verbal + Motor, 3-15) minus Pupil Reactivity Score (PRS). PRS = 0 if both pupils react to light, 1 if one pupil is unreactive, 2 if neither pupil reacts. GCS-P range is 1-15.

Pearls and pitfalls

  • Developed from the IMPACT and CRASH databases to extend the GCS's prognostic range beyond its floor of 3.
  • A GCS-P of 1 (GCS 3 with both pupils unreactive) identifies a subset with especially poor prognosis that GCS 3 alone does not distinguish.
  • Assess pupils before sedation or paralytics are given whenever possible, since these can transiently affect reactivity.

References

  1. Brennan PM, Murray GD, Teasdale GM. Simplifying the use of prognostic information in traumatic brain injury. Part 1: The GCS-Pupils score: an extended index of clinical severity. J Neurosurg. 2018;128(6):1612-1620.