An 84-year-old man presents to clinic with a 6- month history of increasing confusion, visual hallucinations, reduced mobility and falls.
What is the most likely cause for his problems?
A. Alzheimer's disease
B. Frontotemporal dementia
C. Dementia with Lewy bodies
D. Parkinson's disease with dementia
E. Vascular dementia
Correct answer: C
The presentation, particularly visual hallucinations, is typical of dementia with Lewy bodies. Patients with Alzheimer's disease tend to present with forgetfulness for recent events and a tendency to repeat conversations, but early motor impairment would be unusual.
Visual hallucinations would be less usual for the other diagnoses.