What is the Glasgow Coma Scale?

The Glasgow Coma Scale (GCS) is a commonly used assessment tool if a person has a head injury, is unconscious or is in a coma. It was developed in the 1970s at the University of Glasgow, hence its name. Two neurology specialists, Graham Teasdale and Bryan Jennet, are credited with its development. It is in wide use in medical facilities around the world, though there are other assessment tools that can be used to determine level of consciousness as well.

There are three things that the Glasgow Coma Scale assesses to evaluate degree of consciousness and these are eye response, movement, and verbal response. Higher scores, with 15 being the highest indicate greater level of consciousness, and in fact, a fifteen would mean a person was fully awake and aware. A three is the lowest score and suggests an extremely deep state of unconsciousness. Scores in all areas are added together to produce total score.

In the eye response assessment, people may get up to a four in score. The following ratings apply:

1. Eyes don’t open
2. Eyes open if pain is applied
3. Eyes open if the person is addressed
4. Eyes open on their own

In motor response on the Glasgow Coma Scale, responses are rated as such:

1. There is no movement
2. The body extends when painfully stimulated
3. The body withdraws abnormally when painfully stimulated
4. The body withdraws normally in response to pain
5. The body responds normally where the pain occurs
6. The person can move and use the body at request of a doctor “Raise your arm, wiggle fingers," etc.

The verbal response on the Glasgow Coma Scale is assessed in the following way:

1. There is no verbal sound
2. The person makes sounds that can’t be understand
3. The person says things that don’t make sense
4. The person can respond to conversation but appears confused, and doesn’t always respond appropriately
5. The person speaks normally with appropriate conversational response.

It’s easy to see why the Glasgow Coma Scale would be useful in assessing adults and children, but might not be as useful in assessing infants who are pre-language. There is a pediatric coma scale adapted from the GCS, which can be used instead, and is in fact often used when children are injured or are hospitalized to continue to assess wellness.

It’s also not always possible to get a completely accurate score on the GCS because of injuries or things like intubation, where a person has a breathing tube. Facial injury may affect eye movement, and injury to the body, particularly paralysis, could affect motor response to pain. A person with a breathing tube cannot speak, though if they are fully conscious, they could write answers and show level of consciousness in this manner.