The Glasgow Coma Scale is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment.
The scale is composed of three tests: eye, verbal and motor responses. The three values separately as well as their sum are considered. The lowest possible GCS (the sum) is 3 (deep coma or death), while the highest is 15 (fully awake person).
Eye response (E)
There are four grades starting with the most severe:
1.No eye opening
2.Eye opening in response to pain stimulus. (a peripheral pain stimulus, such as squeezing the lunula area of the patient's fingernail is more effective than a central stimulus such as a trapezius squeeze, due to a grimacing effect).
3.Eye opening to speech. (Not to be confused with the awakening of a sleeping person; such patients receive a score of 4, not 3.)
4.Eyes opening spontaneously
Verbal response (V)
There are five grades starting with the most severe:
1.No verbal response
2.Incomprehensible sounds. (Moaning but no words.)
3.Inappropriate words. (Random or exclamatory articulated speech, but no conversational exchange. Speaks words but no sentences.)
4.Confused. (The patient responds to questions coherently but there is some disorientation and confusion.)
5.Oriented. (Patient responds coherently and appropriately to questions such as the patient’s name and age, where they are and why, the year, month, etc.)
Motor response (M)
There are six grades:
1.No motor response
2.Decerebrate posturing accentuated by pain (extensor response: adduction of arm, internal rotation of shoulder, pronation of forearm and extension at elbow, flexion of wrist and fingers, leg extension, plantarflexion of foot)
3.Decorticate posturing accentuated by pain (flexor response: internal rotation of shoulder, flexion of forearm and wrist with clenched fist, leg extension, plantarflexion of foot)
4.Withdrawal from pain (Absence of abnormal posturing; unable to lift hand past chin with supra-orbital pain but does pull away when nailbed is pinched)
5.Localizes to pain (Purposeful movements towards painful stimuli; e.g., brings hand up beyond chin when supra-orbital pressure applied.)
6.Obeys commands (The patient does simple things as asked.)
Interpretation
Individual elements as well as the sum of the score are important. Hence, the score is expressed in the form "GCS 9 = E2 V4 M3 at 07:35".
Generally, brain injury is classified as:
Severe, with GCS < 8-9
Moderate, GCS 8 or 9–12
Minor, GCS ≥ 13.
Generally when a patient is in a decline of their GCS score, the nurse or medical staff should assess the cranial nerves and determine which of the twelve have been affected.
