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Prolonged disorders of consciousness (vegetative state, minimally conscious state, locked-in)
The difference between wakefulness without response (vegetative state) and the minimally conscious state is a single, repeated sign of awareness — so assessment is repeated with a structured scale (CRS-R), because about a third to a half of "bedside" diagnoses are wrong.
Why it matters in the exam
Coma: eyes closed, no sleep-wake cycle and no response. Vegetative state (now also called "unresponsive wakefulness syndrome", UWS): eyes open, there is a sleep-wake cycle, but all responses are reflexive. Minimally conscious state (MCS): limited but reproducible signs of awareness — command following, visual pursuit, appropriate emotional response or purposeful reaching; MCS+ includes language signs (command following, verbalisation), and MCS- does not. Emergence from MCS is declared when there is reliable functional communication or functional object use.
Under the 2018 AAN guideline, the recommended scale is the JFK Coma Recovery Scale-Revised (CRS-R), and repeated assessments by an experienced team reduce errors. Prognosis is better after traumatic than non-traumatic injury (such as anoxia), and better in MCS than in the vegetative state. The guideline recommended dropping the term "permanent" and using "chronic": after 3 months in non-traumatic injury and after 12 months in traumatic injury the chance of recovery falls, but it is not zero. Amantadine (usually 100–200 mg twice daily) between 4 and 16 weeks after traumatic injury speeds the rate of functional recovery.
Locked-in is not a disorder of consciousness: the patient is awake and aware, with paralysis of all four limbs and of speech and swallowing muscles, but vertical eye movements and blinking are preserved — and communication goes through them. The classic cause is a lesion of the front (ventral) part of the pons, usually from basilar artery occlusion. General care in disorders of consciousness includes preventing complications (pressure injuries, contractures, aspiration, spasticity), feeding, and structured support and information for the family. Akinetic mutism (bilateral medial frontal lesion) looks similar, but the patient is awake and follows with the eyes, with very little movement and speech.
Key points
- UWS — wakefulness without awareness; MCS — partial, reproducible awareness.
- CRS-R with repeated assessments.
- Better prognosis in trauma and in MCS.
- Amantadine at 4–16 weeks after traumatic injury.
- Locked-in — aware, paralysed, vertical eye movements.
Summary table
| State | Eyes and sleep-wake | Awareness | Distinguishing clue |
|---|---|---|---|
| Coma | Closed, no cycle | None | No eye opening |
| Vegetative state (UWS) | Open, cycle present | None | Reflexive responses only |
| MCS | Open, cycle present | Partial and reproducible | Visual pursuit, command following at times |
| Emergence from MCS | Awake | Relatively full | Functional communication or functional object use |
| Locked-in | Awake | Full | Complete paralysis with preserved vertical eye movements |
A free exam question
מה לא נכון לגבי in syndrome - locked ? (the question as examined, in Hebrew)
- א. תנועות עיניים וורטיקליות שמורות
- ב. תחושות מצב וויברציה פגועות
- ג. נגרם מנזק בחלק הקדמי של הפונס
- ד. EEG תקין בפגיעה מסוג זה
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Sources
- AAN/ACRM/NIDILRR Practice guideline update: Disorders of consciousness, 2018 — Diagnosis, prognosis and treatment
- Giacino et al.: Placebo-controlled trial of amantadine for severe traumatic brain injury, 2012 — Amantadine and recovery rate
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.