A Composite MR Neuroimaging Marker for Alzheimer's Disease

The onset of Alzheimer's disease is insidious and the boundary between normal aging and Alzheimer's disease is blurred. In order to prevent and treat Alzheimer's disease, the investigators must be able to mark its preclinical stage, before brain damage becomes irreversible. There is a substantial body of research dealing with predictive markers of Alzheimer's disease in individuals with mild cognitive impairment (MCI). Despite these advances, however, researchers have not had enough evidence to recommend specific techniques that mark preclinical Alzheimer's disease. This new functional MRI (fMRI) index may fill this gap. Participants will have two visits, one for memory testing and neurological examination, and one for an MRI scan. Each visit will take approximately 1½ hours. For volunteers who wish to do so, all study procedures may be completed in a single visit. Participants with MCI will be followed annually. The investigators are currently enrolling healthy volunteers, as well as individuals with MCI (memory loss that does not significantly affect normal daily activities), Alzheimer's disease, and frontotemporal dementia (includes primary progressive aphasia).