Complete unresponsiveness to external stimuli is most consistent with which state?

• A. Coma
• B. Stupor
• C. Lethargy
• D. Obtundation

Answer: (A)

Complete unresponsiveness to external stimuli points to a state where there is no wakefulness or purposeful interaction with the environment. That describes a coma, where the person does not wake up or respond to questions or pain, though reflexes may remain and certain brainstem activities can persist.

In contrast, stupor involves being largely unresponsive but with the possibility of brief, vigorous stimuli eliciting a short, non-sustained response; lethargy refers to drowsiness with the ability to be awakened and respond, albeit slowly; obtundation means reduced alertness and slowed thinking, with easier arousal but diminished responsiveness. Thus, only coma fully matches the description of complete unresponsiveness to external stimuli.