Glasgow Coma Scale

Glasgow Coma Scale (named after the University of Glasgow in Scotland, where it was developed in 1974) is a standardized medical scoring system intended for the objective, rapid, and reproducible assessment of consciousness level in patients with traumatic brain injuries.

Etiology and pathophysiology

A person’s level of consciousness depends on the coordinated work of the cerebral cortex and the brainstem’s activating system. In severe trauma, brain tissue swelling, or growing hematoma, these structures are compressed or experience oxygen deprivation, which consistently leads to impaired alertness.

The scale does not evaluate the cause of the coma, it mathematically measures the depth of neurological deficit. Assessment is based on testing three fundamental responses of the nervous system: eye-opening (as a response to sound or pain), verbal response (the ability to speak and be oriented), and motor response (the ability to follow commands or withdraw a hand from a painful stimulus).

Clinical significance

Each reaction is assigned a specific score. The total score ranges from 3 points (terminal coma or brain death, complete absence of any reactions) to 15 points (clear consciousness, patient fully adequate).

This tool revolutionized neurotraumatology by enabling emergency medical personnel, resuscitators, and neurosurgeons to speak a common language. The scale determines rescue tactics. Thus, a score of 8 or below is the absolute world standard for the immediate initiation of mechanical ventilation (intubation) as the brain loses its ability to independently protect the airways at this level.