- Written by Eric Steinberg DO, MEHP
- REBEL EM
- Medical Category: Neurology, Trauma
- brainstem reflexes, coma scale, FOUR Score, full outline of unresponsiveness, gcs, gcs alternatives, glasgow coma scale, level of consciousness, loc, MDCalc, MDCalc Wars, motor score, neuro exam, neuro monitoring, neurological assessment, simplified motor scale, sms score, TBI, trauma evaluation, Traumatic Brain Injury
🗝️ Key Points
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- ⚡ Use SMS: When you need a fast, reliable severity snapshot and a full GCS is impractical.
- 🫁🧠 Use FOUR: When the patient is intubated or you need brainstem reflexes + breathing pattern to trend severity.
- 🗣️👀💪 Use GCS: When verbal is obtainable and you want the most familiar “common language” score.
🤕 Case
A 35 yo male patient arrives after a high-speed MVC with obvious head trauma. He’s confused, intermittently combative, and requires rapid sedation for imaging. After CT, the team attempts to calculate a Glasgow Coma Scale (GCS)—but sedation, intubation, and a changing neuro exam make the score hard to interpret. The question becomes practical, not academic:
If GCS isn’t feasible, what should we use to document and trend neurologic status right now?
🔗 Scoring Tools
🎯 Quick Hits
💬 Case Resolution
Following CT, the patient remains intubated and sedated, making the verbal GCS unreliable. The team documents neurologic status using the FOUR score, which allows assessment of motor response, brainstem reflexes, and respiratory pattern despite intubation. Serial FOUR scores provide a clearer neurologic trend for ICU handoff and neurosurgical consultation.
❓ FAQ
- What is the Simplified Motor Scale (SMS) used for?
A rapid motor-only coma scale for quick severity assessment when a full GCS is impractical. - Why doesn’t GCS work well in intubated or delirious/sedated patients?
The verbal component becomes unusable, and sedation can depress eye/motor responses—making the total score misleading. - When should I use FOUR instead of GCS?
When the patient is intubated, or when you need to trend brainstem reflexes and breathing pattern. - How often should SMS/FOUR be reassessed in severe neurologic illness?
With any clinical change, after key interventions (sedation changes, procedures), and at scheduled neuro-check intervals per local protocol. - Can non-neurologic factors distort these scores?
Yes—sedatives, paralysis, intoxication, hypoxia, and shock can confound results. Document confounders with the score. - Does SMS replace GCS for mild floor-level patients?
Usually no—GCS remains the common language when feasible; SMS is best as a fallback when GCS is impractical.
🚨 Clinical Bottom Line
- GCS: Still the standard—but can mislead in sedated, intubated, or nonverbal patients (verbal is unusable; meds can depress eye/motor).
- Simplified Motor Scale (SMS): Fast, motor-only option when you just need a quick severity snapshot.
- FOUR Score: Best when brainstem function or ventilatory status matters—especially in intubated patients.
Post Peer Reviewed By: Marco Propersi, DO (Twitter/X: @Marco_Propersi), and Mark Ramzy, DO (X: @MRamzyDO)
🧭 Prep Sheets
👤 Author
Eric Steinberg
DO, MEHP
Content Director, MDCalc, Residency Director, Emergency Medicine St. Joseph's University Medical Center, Paterson, NJ
