Quick GuideConcussions & Brain Injuries: Symptoms, Tests, Treatment

The Glasgow Coma Scale was developed to provide health care practitioners a simple way of measuring the depth of coma based upon observations of eye opening, speech, and movement. Patients in the deepest level of coma:

• do not respond with any body movement to pain,
• do not have any speech, and
• do not open their eyes.

Those in lighter comas may offer some response, to the point they may even seem awake, yet meet the criteria of coma because they do not respond to their environment.

An awake person has a Glasgow Coma Scale of 15, while a person who is dead would have a score of 3. The abnormal motor responses of flexion and extension describe arm and leg movement when a painful stimulus is applied. The term "decorticate" means that the cortex of the brain, the part that deals with movement, sensation, and thinking, is not working. "Decerebrate" means that the cerebrum (the whole brain), the cortex, and the brainstem that controls basic bodily functions like breathing and heartbeat, is not working.

The scale is used as part of the initial evaluation of a patient, but does not assist in making the diagnosis as to the cause of coma. Since it "scores" the level of coma, the Glasgow Coma Scale can be used as a standard method for pre-hospital emergency providers to determine the severity of head injury. It also allows the next provider in the chain of care to compare their assessment to the previous one. In this way, there is a standard score to determine whether the patient is improving or decompensating from the injury scene during the transitions to the ER, to the operating room, or ICU.