Affiliations: Department of Neurology and Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA | Sanders-Brown Center on Aging and Alzheimer's Disease Center, Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
Correspondence:
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Corresponding author: Gregory A. Jicha, M.D., Ph.D., Sanders-Brown Center on Aging, University of Kentucky College of Medicine, 800 South Limestone Street, Lexington, KY 40536-0230, USA. Tel.: +1 859 257 1412 x255; Fax: +1 859 257 3819; E-mail: gajich2@email.uky.edu.
Abstract: Over the past several decades, our understanding of Alzheimer's disease (AD) has seen an evolution from the dichotomous concept of normal versus AD in the dementia state to a more accurate and complete appreciation of AD as a progressive disorder with clinical, biological, and pathological features occurring along a continuum from normal to end-stage disease. Integrating our understanding of the relationships and interplay between the clinical, biological, and pathological features of AD may allow the identification of AD at even preclinical, completely asymptomatic stages of the disease. This review attempts to summarize the clinical stages of AD in terms of epidemiology, historical evolution of disease stage diagnoses, cognitive/neuropsychologic features, psychiatric/behavioral manifestations, and functional decline in the context of our developing understanding of the biological processes responsible for the pathogenesis of AD described in detail in the accompanying articles.
Keywords: Alzheimer's disease, clinical features, mild cognitive impairment, preclinical AD
