The Glasgow Coma Scale - (GCS) (Teasdale and Jennett 1974)

The sum of three coded values that describe a patient’s BEST motor (1–6) verbal (1–5), and eye (1–4) response to speech or pain.

 

The GCS is scored between 3 and 15, 3 being the worst, and 15 the best, using three parameters :

  • Best Eye Response

  • Best Verbal Response

  • Best Motor Response

Best Eye Response. (4) Best Verbal Response. (5) Best Motor Response. (6)
1 No eye opening 1 No verbal response 1 No motor response.
2 Eye opening to pain. 2 Incomprehensible sounds. 2 Extension to pain.
3 Eye opening to verbal command 3 Inappropriate words. 3 Flexion to pain.
4 Eyes open spontaneously 4 Confused 4 Withdrawal from pain.
  5 Orientated 5 Localising pain
    6 Obeys Commands


Note that the phrase 'GCS of 11' is essentially meaningless, and it is important to break the figure down into its components, such as E3V3M5 = GCS 11.

A Coma Score of 13 or higher correlates with a mild brain injury, 9 to 12 is a moderate injury and 8 or less a severe brain injury.
 

The motor component of the GCS score is a powerful predictor of outcome and contains most of the predictive power of the score.

There are two circumstances in which the motor-only model is unreliable: in patients with pharmacologic (therapeutic) paralysis and in patients with traumatic paralysis (i.e., high spinal cord injuries). In these cases, the motor score is simply not a measure of consciousness and cannot be used as one.


Limitations of GCS:

  • Its important to remember the GCS does not just measure Brain injury but also brain function which can be affected by many things.

  • Patients who are inebriated, intubated, or pharmacologically paralyzed cannot have their GCS assessed.

  • “[the] validity of the assumption that each of the three parts of the scale should count equally and that each step should differ equally from that next to it has still to be tested.”

  • Some believe the eye subscore should be removed from the GCS because it adds nothing to the predictive power of the model and is occasionally impossible to obtain.

Geasdale G, Murray G, Parker L, Jennett B. Adding up the Glasgow Coma Score. Acta Neurochir Suppl (Wien). 1979; 28: 13–19

Healey, C. MD. Osler, Turner M. MD. Rogers, Frederick B. MD. Healey, Mark A. MD. Glance, Laurent G. MD. Kilgo, Patrick D. MS. Shackford, Steven R. MD. Meredith, J. Wayne MD. Improving the Glasgow Coma Scale Score: Motor Score Alone Is a Better Predictor. Journal of Trauma-Injury Infection & Critical Care. 54(4):671-680, April 2003

http://www.sfar.org/scores2/glasgow2.html - GCS calculator

Last updated 11/09/2015