Glasgow Coma Scale and GCS-P
Level of consciousness, the pupil response, and where the patient should go · v1- Record the best response in each of the three domains, and the pupil reaction.
- Where a domain cannot be tested, in an intubated patient or one with severe periorbital oedema, mark it Not Testable and the total is adjusted.
- You get the total, the GCS-P after the pupil deduction, and the disposition that level of consciousness calls for.
- Read the trend rather than the single reading. Sedation, aphasia and a language barrier all move the number, and the tool says when the score is contaminated.
- Children below 5 years, in whom the adult verbal scale does not apply and the paediatric Glasgow Coma Scale is used instead.
- The cause of the impaired consciousness. The score records what the patient does, not why.
- Brainstem function beyond the pupil response, which is the one brainstem sign this scale carries.
- The management that follows the number: intracranial pressure control, the neurosurgical decision, and the interpretation of the imaging it asks you to arrange.
1. Patient Characteristics
2. Clinical Context & Confounders
3. Glasgow Coma Scale Parameters
1. The Evolution of the GCS
Teasdale and Jennett described the scale in 1974, and it is still the measure of the depth and duration of impaired consciousness against which the others are judged. What it does not look at is the brainstem.
2. GCS-P: Incorporating Pupillary Reactivity
The GCS-Pupils (GCS-P) score integrates brainstem function with the standard GCS. It is calculated by subtracting the Pupillary Reactivity Score (PRS) from the GCS total:
- PRS 0: Both pupils react.
- PRS 1: One pupil reacts.
- PRS 2: Neither pupil reacts.
Why the pupils are added: A GCS of 3 with bilateral fixed pupils (GCS-P 1) and a GCS of 3 with reactive pupils (GCS-P 3) are the same number on the old scale and two very different patients. Mortality is far worse in the first.
3. Confounding Factors in the Ward and ICU
| Confounder | Clinical Strategy |
|---|---|
| Intubation & Sedation | An intubated patient does not score Verbal 1. Assign "NT" (Not Testable) and append a "T" to the score (e.g., E4 VT M6). Book a daily sedation pause, because a score recorded through sedation is not this patient's baseline and will be read later as though it were. |
| Periorbital Oedema | Common in severe maxillofacial trauma. Do not assign an Eye score of 1. Mark as "NT" with modifier "C" (Closed). |
| Aphasia / Dementia | Record the best baseline function. A patient with severe baseline aphasia cannot score a Verbal 5, but changes from their baseline indicate acute deterioration. |
4. Relevance in the Indian Context
Indian epidemiological data put road traffic accidents behind most severe TBI presentations. The delay in reaching a neurosurgical centre is where the secondary injury happens, through hypoxia and hypotension. Protect the airway at the primary centre before the patient is moved, every time. In the non-traumatic encephalopathies, hepatic encephalopathy and severe CNS tuberculosis among them, the trend in GCS over hours predicts outcome far better than any single reading does.
References
- Teasdale G, Jennett B. Assessment of coma and impaired consciousness. A practical scale. Lancet. 1974;2(7872):81-84. PMID 4136544.
- Teasdale G, Maas A, Lecky F, Manley G, Stocchetti N, Murray G. The Glasgow Coma Scale at 40 years: standing the test of time. Lancet Neurol. 2014;13(8):844-854. PMID 25030516.
- 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. PMID 29631516.
- Murray GD, Brennan PM, Teasdale GM. Simplifying the use of prognostic information in traumatic brain injury. Part 2: Graphical presentation of probabilities. J Neurosurg. 2018;128(6):1621-1634. PMID 29631517.
- Reilly PL, Simpson DA, Sprod R, Thomas L. Assessing the conscious level in infants and young children: a paediatric version of the Glasgow Coma Scale. Childs Nerv Syst. 1988;4(1):30-33. PMID 3135935.
- Carney N, Totten AM, O'Reilly C, et al. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery. 2017;80(1):6-15. PMID 27654000.
- Gururaj G. Epidemiology of traumatic brain injuries: Indian scenario. Neurol Res. 2002;24(1):24-28. PMID 11783750.
- Agrawal A, Galwankar S, Kapil V, et al. Epidemiology and clinical characteristics of traumatic brain injuries in a rural setting in Maharashtra, India. 2007-2009. Int J Crit Illn Inj Sci. 2012;2(3):167-171. PMID 23181212.
Two entries were corrected on 28 August 2026. Reference 8 was previously cited as Indian J Surg. 2012;74(1):21-25 with a shortened title; the same authors published that work in the International Journal of Critical Illness and Injury Science, and the citation now matches the paper. A ninth entry, Sharma R, Singh R, et al. Profile of traumatic brain injury in an Indian tertiary care centre. Neurol India. 2019;67(4):1042-1048, could not be traced in PubMed by citation, by title or by author on 28 August 2026 and has been withdrawn rather than left standing.
How to Cite This Tool
DOIhttps://doi.org/10.5281/zenodo.22401582
AMA Style:Umakanth S. Glasgow Coma Scale and GCS-P. Version 1. MEDiscuss Clinical Decision Support System. Published 2026. Accessed . https://mediscuss.org/cdss/glasgow-coma-scale. doi:10.5281/zenodo.22401582
Vancouver Style:Umakanth S. Glasgow Coma Scale and GCS-P [Internet]. Version 1. MEDiscuss.org; 2026 [cited ]. Available from: https://mediscuss.org/cdss/glasgow-coma-scale. doi:10.5281/zenodo.22401582
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