Glasgow Coma Scale (GCS)

Severity tiers and what they mean

• 13–15 — Mild brain injury. Observe, neuro checks q1–2h, head CT if focal findings or persistent vomiting.
• 9–12 — Moderate brain injury. Frequent neuro checks, CT, often admission to step-down or ICU.
• ≤ 8 — Severe brain injury. Intubation indicated — the patient cannot protect the airway. ICU.

How to score each component

Eye opening (E, 4 → 1)

• 4 — Eyes open before you do anything.
• 3 — Eyes open when you call their name.
• 2 — Eyes open only with painful stimulus (trapezius pinch, sternal rub).
• 1 — Eyes do not open at all.

Verbal (V, 5 → 1)

• 5 — Knows person, place, time.
• 4 — Conversational but confused (wrong year, doesn't know hospital).
• 3 — Random words, no coherent thought.
• 2 — Moans, groans.
• 1 — Silent.

Motor (M, 6 → 1)

• 6 — Follows commands ("squeeze my hand").
• 5 — Localizes — moves a hand toward the painful stimulus.
• 4 — Withdraws — pulls away from pain.
• 3 — Decorticate posturing — flexed arms, "to the cor(e)".
• 2 — Decerebrate posturing — extended arms, the worse pattern.
• 1 — No motor response.

Pediatric GCS

For preverbal children (under 2), the verbal scale is replaced: 5 = coos/babbles, 4 = irritable cry, 3 = cries to pain, 2 = moans to pain, 1 = none. Eye and motor scoring are unchanged.

Common pitfalls

• Stimulating wrong. Use trapezius pinch or supraorbital pressure for central pain. Nail-bed pressure tests peripheral response only.
• Confusing decorticate and decerebrate. "Cor(e)" = flexed toward the core (3). "DecErebrate" = Extended (2). Decerebrate is worse — it implies brainstem involvement.
• Documenting a GCS without trend. A GCS of 12 today, 11 yesterday, 10 the day before is a trajectory you must escalate, even though no individual number is ≤ 8.