Sleep and circadian disruptions in early Alzheimer's Disease

Sleep and circadian disruptions are a common complaint in patients with early Alzheimer's disease (AD). A fragmented sleep/wake pattern, characterized by increased daytime activity and disrupted nighttime sleep, is frequently observed. Sundowning, or the presence of certain psychological symptoms and behaviour at specific times of the day, has also been noted in AD patients. Because individuals with mild cognitive impairment (MCI) often develop AD, it is important to understand the disturbances that occur in both of these populations to determine the patterns of change over time. The sleep habits of healthy aged adults, those with MCI, and early AD patients, will be assessed in this study via questionnaires. A caregiver version of the questionnaire will also be given, where appropriate. Their sleep/wake activity will be analyzed using actigraphy, a wrist-watch-like measure of motor activity that corrects with sleep recordings. Participants will also be screened for cognitive impairments with the mini-mental state exam. Combining this information will help determine targets for clinical intervention in those with MCI and early AD. Specifically, understanding the changes in sleep and circadian rhythms that occur in individuals with MCI and early AD will aid in structuring a day/night regimen that may slow disease progression, as well as delay institutionalization.