Glasgow Coma Scale

Have you ever asked "How is a brain injury diagnosed?".  When someone suffers a traumatic brain injury, their state of consciousness is usually affected. Doctors use a neurological tool called the Glasgow Coma Scale (GCA) to judge the degree of consciousness. Immediately after a person sustains a possible brain injury or head trauma, the EMT, nurse, or emergency doctor uses the GCA to determine how conscious or comatose the victim is.

Using The Glasgow Coma Scale

The scale assigns a number from 3 to 15 with higher numbers denoting a higher degree of consciousness. So a patient with a Glasgow Coma Scale score of 8 and below signifies severe brain injury, a score between 9 and 12 shows moderate brain injury, and a score above 13 would be a minor brain injury.

The Glasgow Coma Scale measures the patient’s highest motor response, verbal response, and eye response. After the first measurement, the GCA can also be used throughout the stay in the hospital to help measure progress and predict the patient's outcome or prognosis.

Glasgow Coma Scale Limitations

Not every brain injury victim is able to respond well to a Glasgow Coma Scale measurement.  If a victim has any pre-existing or special conditions that could limit their responses, they may not be a good candidate. Additionally, breathing apparatus such as an endotracheal tube would also limit the patient's ability to respond—in this case, verbally. Other factors that hamper an accurate measurement are intoxication, drug overdose, shock, low blood oxygen (hypoxemia), or various other metabolic disturbances. A spinal cord injury would limit movement thereby inhibiting the best motor response score. Serious orbital trauma would limit eye opening. The scale also has limited use with children, especially under 3 years. However, it’s modified to accommodate young brain injury victims.

Still, the Glasgow Coma Scale is one of the most commonly used assessment tools for brain injury victims. It was first formulated in 1974 by Glasgow University neurology professors, Bryan Jennett and Graham Teasdale. Now used worldwide to evaluate head traumas, it has stimulated the creation of other assessment tools.

Some experts argue whether or not a Glasgow Coma Scale score can determine the potential for recovery, after all, it is not exact science.  Generally, the scores measured within 24 hours after the occurrence of the brain injury or head trauma, will be the best guide to the ultimate result, that is, temporary or long term disability. Yet, brain injury victims differ based on various factors which can’t be measured. So only time and the effort put into healing will eventually determine the degree of brain injury recovery.