A 78-year-old man is brought to the emergency department by…
A 78-year-old man is brought to the emergency department by his daughter, who reports that he has been increasingly confused over the past two days. He has difficulty focusing, frequently changes topics mid-sentence, and becomes agitated in the evening. His medical history includes hypertension and mild cognitive impairment. Which feature most strongly supports a diagnosis of delirium rather than dementia?