Glasgow Coma Scale

What is the Glasgow Coma Scale?

The Glasgow Coma Scale is a rapid bedside assessment of consciousness after head injury. It scores three categories of response and adds them into a single total.

It was developed to give clinicians a consistent shorthand for describing a patient's neurological state, replacing vague descriptions like stuporous or obtunded.

Scores are recorded repeatedly rather than once, because change over time is often more informative than any single figure.

The earliest score, frequently taken by paramedics at the scene, carries particular weight because it captures the state closest to the injury itself.

What does the score measure?

Three response categories are assessed and combined.

• Eye opening, from spontaneous through to none
• Verbal response, from oriented conversation through to none
• Motor response, from obeying commands through to none
• The categories are added into a total, with lower totals indicating deeper impairment
• Severity bands group the totals into mild, moderate and severe injury

How is the score used in a claim?

As corroboration of severity. A low score documented at the scene supports the argument that a significant brain injury occurred, independent of how the person presents later.

It also establishes a timeline, since serial scores show whether the person deteriorated after arrival, which can raise questions about monitoring and treatment.

For a brain injury claim it is one of the few objective early data points, which is valuable when later symptoms are invisible.

What are its limits?

It does not predict long term outcome reliably. People with low initial scores sometimes recover well, and people with normal scores sometimes have lasting deficits.

It is also confounded by intoxication, sedation, intubation and facial injury, all of which are common in trauma and any of which can distort the verbal component.

Defence experts frequently point to a high initial score to argue no significant injury occurred, which is why later symptom documentation matters just as much.

The score is best treated as one data point within a broader picture rather than as a measure of what someone will live with.

Common questions

Does a normal score mean I have no brain injury?

No. Mild traumatic brain injury frequently presents with a normal or near normal score, and symptoms may emerge over the following days.

Why do the recorded scores differ?

Scores change over time and are recorded by different clinicians. Serial documentation showing the trend is more meaningful than any single figure.

Does intubation affect the score?

Yes. An intubated patient cannot produce a verbal response, so the component is recorded differently and the total is interpreted with that in mind.