Teasdale and Jennett introduced the Glasgow Coma Scale (GCS) in 1974 to replace inconsistent, unstandardized coma terminology. The scale independently scores three behavioral domains: motor response, verbal response, and eye opening. It was designed for reliable use by non-specialist nursing and junior medical staff in any hospital setting.
Published coma classification systems before 1974 ranged from 3 to 17 levels, defined so vaguely that a simple yes/no judgment of "conscious or unconscious" still produced 20% disagreement between observers.
When you assess a head-injured patient in the ED, document all three GCS subscores separately — not just the total. A patient who cannot be verbally scored due to intubation has a fundamentally different assessment than one who is truly aphasic; collapsing them into the same total obscures the distinction.
Never test eye opening to pain at the supraorbital ridge or jaw angle. The grimacing response causes eye closure and will falsely lower the score. Use a limb stimulus. In locked-in syndrome, a normal motor score is impossible. The patient may be fully conscious but score 1 on motor. Always document untestable components explicitly rather than recording them as no response.
Teasdale and Jennett introduced the Glasgow Coma Scale (GCS) in 1974 to replace inconsistent, unstandardized coma terminology. The scale independently scores three behavioral domains: motor response, verbal response, and eye opening. It was designed for reliable use by non-specialist nursing and junior medical staff in any hospital setting.
Published coma classification systems before 1974 ranged from 3 to 17 levels, defined so vaguely that a simple yes/no judgment of "conscious or unconscious" still produced 20% disagreement between observers.
When you assess a head-injured patient in the ED, document all three GCS subscores separately — not just the total. A patient who cannot be verbally scored due to intubation has a fundamentally different assessment than one who is truly aphasic; collapsing them into the same total obscures the distinction.
Never test eye opening to pain at the supraorbital ridge or jaw angle. The grimacing response causes eye closure and will falsely lower the score. Use a limb stimulus. In locked-in syndrome, a normal motor score is impossible. The patient may be fully conscious but score 1 on motor. Always document untestable components explicitly rather than recording them as no response.