Which statement best differentiates delirium from dementia in neuro patients?

• A. Delirium is chronic and progressive; dementia is acute and fluctuating
• B. Delirium always includes hallucinations
• C. Delirium presents with gradual memory decline and stable attention
• D. Delirium is an acute, fluctuating disturbance of attention and awareness; dementia is chronic, progressive with gradual memory decline

Answer: (D)

The distinction centers on onset and course. Delirium is an acute, fluctuating disturbance of attention and awareness, usually triggered by an underlying medical issue, infection, medications, or withdrawal. Dementia, in contrast, is a chronic, progressive syndrome with gradual memory decline and impairment in other cognitive domains, while consciousness and attention are not acutely fluctuating in the early stages.

This is why the best statement correctly identifies delirium as an acute, fluctuating disturbance of attention and awareness and dementia as a chronic, progressive condition with gradual memory decline. The other options misstate either the timing (delirium is not chronic and progressive) or the core features (delirium does not require hallucinations, and attention is not stable in delirium).