Circadian Rhythm and Other Factors in Memory Clinic Patients

The diagnosis of Alzheimer's disease and other related dementias is mainly based on assessment of cognitive, behavioral and neuropsychological symptoms, functional limitations and imaging data/cerebrospinal fluid (CSF) biomarkers in some cases. These measures are primarily used in specialized clinics leading to a potential large number of dementia cases not being diagnosed. With population ageing, the number of people living with dementia is increasing and there is an urgent need for cost-effective, scalable tool for early, accurate screening of dementia cases, including both AD and other types of dementia, in primary care. Furthermore, the factors associated with the progression of the different types of dementia are still poorly understood, limiting the prospects for intervention to improve the quality of life of patients and their caregivers and to slow the progression of the disease. This project aims to identify circadian rhythm components and other individual risk factors that could be used in primary care for dementia diagnosis (including its subtypes: AD, Lewy bodies, vascular, frontotemporal dementia) and stages (cognitively healthy, mild cognitive impairment, clinical dementia). A secondary objective is to determine factors associated with progression of the disease, in terms of cognitive decline and limitations in activities of daily living, as well as progression to dementia among cognitively healthy controls and patients with mild cognitive impairment. This will be achieved using data from 1500 patients from 2 memory clinics in Paris from who data on sociodemographic, behavioral, and health related factors (such as reported sleep disturbance, plasma biomarkers, retina measures (in a subsample, CIRCAME-EYE) and audiological parameters (CIRCAME-Ear substudy)) will be measured at inclusion interview. Baseline examination will also include a wrist-mounted device for a measure of circadian rhythm and its related behaviors (physical activity and sleep), for which disruptions are thought to characterize dementia subtypes and stages. Information on dementia diagnosis and stages will come from memory clinic routine visits at the time of the inclusion; they will include subtypes (AD, Lewy bodies, vascular, frontotemporal dementia), cognitive stages (cognitively healthy, mild cognitive impairment, clinical dementia) and AD stages based on CSF biomarkers and clinical measures. Information on progression of the disease (change in cognitive function using the mini-mental status examination, change in limitations in activity of daily living) and incidence of dementia, institutionalization and mortality will be retrieved from patients' routine visits at memory clinics up to 15 years after the inclusion period.