Alzheimer's disease and other dementias: a review.

Dementia and its associated diseases are important causes of disability and morbidity in developed countries, especially in the aged population. As the babyboomers arrive at retirement and individuals over 100 are one of the fastest growing segments of our nation's population, we may realize the substantial cost these diseases bring to society. Dementia is characterized by a significant loss of cognitive function and should be clinically distinguished from an acute delirium or decreased arousal. Its manifestations cause anguish to millions of caregivers and family members, who are pressed to cope with their loved one's unfortunate decline in multiple cognitive domains, functioning, and behavior. Early detection and management may prevent overuse of costly medical resources and allow patients and family members time to prepare for future medical, financial, and emotional challenges. Diagnostic clues to the etiology of the patient's dementia can be found in a medical workup in which the neurologic history and examination (including mental status examination) are essential and neuroimaging is indicated. Herein, the concept of central nervous system (CNS) degenerative diseases as disorders of specific proteins is introduced. This review is intended to summarize clinical, biological, and genetic features of the common subtypes of dementia, and bring light to potential benefits of early and accurate diagnoses to optimize treatment. Details of the various diseases remain only partially uncovered, raising extensive prospects for future research and therapy for patients with dementia.