Glasgow Coma Scale

The Glasgow Coma Scale is a scale designed to practically assess the level of alertness in humans.

It was created in 1974 by Bryan Jennett and Graham Teasdale, members of the Institute of Neurological Sciences at the University of Glasgow, as an objective assessment tool of the state of consciousness for victims of head trauma.

Its precision and relative simplicity later extended its application to other traumatic and non-traumatic pathologies.

History

The Glasgow Scale was designed by the English neurosurgeons Graham Teasdale and Bryan Jennett, when they published it in 1974 in The Lancet magazine, in the article entitled «Assessment of coma and impaired consciousness. A practical scale» [«Assessment of coma and altered state of consciousness. A practical scale»].

This first edition of the scale was made up of 3 categories to be evaluated: eye opening, verbal and motor response that gave a sum of 14 points. In 1976, a point was added to the scale to assess abnormal flexion (decortication posture), in the motor response category, giving a total of 15 points, as is known to date.

Description of the scale

The scale is made up of the exploration and quantification of three parameters: eye opening, verbal response and motor response. Giving a given score to the best answer obtained in each category. The score obtained for each of the three is added, thus obtaining the total score. The lowest value that can be obtained is 3 (1 + 1 + 1), and the highest is 15 (4 + 5 + 6).

Interpretation

In traumatic brain injury, the score obtained is the element used to define the severity of the condition according to Gennarelli's classification, and it is useful to define some of the diagnostic and therapeutic behaviors during initial management. Its application in repeated examinations makes it possible to monitor fluctuations in the state of consciousness, which is very useful in the early phase of treatment.