Sleep-related behaviors in Alzheimer's disease and dementia with Lewy bodies.

: Abstract Prevalence studies suggest that Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) are the most common dementing illnesses in the elderly. The aim of this narrative review was to provide data on sleep-related behaviors in AD and DLB. This paper contains arguments, with a clinical approach, on both circadian rhythm changes and dissociated states of wakefulness and sleep in these two conditions.