Which feature is typical of delirium but not early dementia?

• A. Impaired attention is typical of delirium.
• B. Memory impairment only with no attention issues.
• C. Delirium is acute, fluctuating, with impaired attention and consciousness; dementia is chronic, progressive with memory impairment.
• D. Dementia presents with fluctuating levels of consciousness.

Answer: (C)

Delirium and early dementia differ mainly in how they start and how their symptoms vary. Delirium starts suddenly and tends to fluctuate—people can swing between more alert and less alert states within hours—and this is paired with problems in attention and often altered level of consciousness. Early dementia, on the other hand, unfolds slowly over time and typically shows a steady, chronic decline with prominent memory impairment, but consciousness remains clear early on and attention is not abruptly disrupted.

So the best way to capture what’s typical for delirium but not for early dementia is the combination of acute, fluctuating symptoms with impaired attention and altered consciousness, contrasted with a gradual, chronic progression where memory loss is key but awareness and attention are usually preserved early. The other statements either oversimplify or misstate the patterns—delirium’s hallmark is the acute, fluctuating, attention- and consciousness-related disturbance, not just memory changes alone, and dementia does not usually present with fluctuating levels of consciousness.