Ranjan Duara, M.D.

Longitudinal Study of Etiological Subtypes of Mild Cognitive Impairment

Diseases of the brain that progress to dementia, such as Alzheimer's disease (AD), Levey Body Dementia (LBD), Vascular Dementia (VascD) and Frontotemporal Dementia (FTD), are preceded by a stage of cognitive impairment at which the patient is not sufficiently handicapped to fulfill criteria for dementia. While "Mild Cognitive Impairment" (MCI)) represents a predominant restriction of memory, "Cognitive Impairment with No Dementia" (CIND) describes impairments in one or more domains that may include memory. In both conditions the functional status of the patient is not (yet) affected. Due to lack of specific classifications MCI and CIND have traditionally been combined under the umbrella of MCI. However to facilitate preservation or improvement of function in the afflicted patients with early treatments it is important to investigate the specific developmental features of the individual impairments. To this end, the study will recruit a cohort of subjects with MCI from the Wien Center and the University of Miami MDC to classify subjects by etiological diagnosis (e.g., MCI-AD, MCI-LBD, MCI-Vasc and MCI-FTD) based on clinical, neuropsychological and neuroimaging features. The goal is to re-evaluate all MCI subjects annually to determine the rate of development of new clinical features, cognitive decline, rate of conversion to dementia of each MCI subtype and their relationships to established specific features of the individual MCI subtypes. The accuracy of the diagnosis of the provisional etiology of MCI will be determined by evaluating the specific dementia to which the MCI subtype has converted.