A follow-up study of actigraphic measures in home-residing Alzheimer's disease patients.

This article reports cross-sectional and follow-up data with actigraphic measures of nocturnal sleep and rest/activity in 61 Alzheimer's disease (AD) patients as well as the relation of actigraphic measures to levels of behavioral disturbance across different stages of the disease. Over the course of approximately 1.5 years' follow-up, patients showed significant deterioration of nocturnal sleep parameters, but no significant change in rest/activity circadian rhythm parameters. There were also significant correlations among nocturnal sleep, rest/activity circadian rhythm, and behavioral disturbance measures, but only in relatively early stages of AD. It is argued that study of nocturnal sleep and circadian rhythm in relation to behavioral disturbance in AD requires longitudinal data and analyses that take into account the stage of disease at which patients are assessed.