Alzheimer's disease with sudden onset of confusion; which factor is most likely?

• A. Infection.
• B. Dehydration.
• C. Possible recent med modification.
• D. New onset tremor.

Answer: (C)

When an Alzheimer’s patient suddenly becomes confused, think delirium—an acute, reversible disturbance of attention and awareness. Delirium is often triggered by a precipitating factor that disrupts brain function, and medications are a leading cause in elderly people who are frequently on multiple drugs.

A recent modification in medication fits best because it directly alters CNS activity, sedative load, or anticholinergic burden, which can quickly precipitate delirium over hours to days. Infections and dehydration can also cause delirium, but they’re not as specifically tied to a recent change in therapy, and the scenario points to a trigger that would most reliably explain a rapid onset of confusion. A new onset tremor is less directly connected to acute cognitive disturbance as the primary driver in this context.