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This chapter addresses the following Geriatric Fellowship Curriculum Milestones: #9, #55, #58
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Learning Objectives
To describe the expected effects of aging on a variety of cognitive functions
To identify age-related medical conditions that can negatively impact cognition
To describe the key clinical features of Alzheimer disease (AD) dementia, as well as current primary tools used for diagnosis
To describe the differences and similarities between AD dementia and other neurodegenerative diseases
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Key Clinical Points
Normal aging is associated with mild changes in circumscribed aspects of cognition; these changes are much less significant than cognitive effects associated with age-related medical conditions and neurodegenerative disease.
Physical disease is often linked with adverse cognitive consequences and increased risk for neurodegenerative disease; effective management of common age-related conditions may thus reduce the negative impact on cognition that is often considered an unavoidable outcome of aging.
Late-onset depression in older adults may be a symptom of prodromal neurodegenerative disease.
Certain medications can lead to adverse cognitive effects and even increased risk for dementia in older adults.
Alzheimer disease dementia is the eventual clinical manifestation of underlying pathology that is often present for years or decades before symptoms are noticed; thus, careful history-taking and new clinical and research tools may aid in early diagnosis.
Non-Alzheimer neurodegenerative diseases typically manifest with distinct cognitive and behavioral symptoms early in the disease process, although differentiation becomes more difficult with advancing dementia.
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“Age does not depend upon years, but upon temperament and health. Some men are born old, and some never grow so.”
Tyron Edwards
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“A man is as old as his arteries.”
Thomas Sydenham
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The dogma that aging brings inevitable cognitive decline is being challenged by studies of the rapidly expanding oldest segment of our society, adults older than 60 years. Although some aspects of cognition are affected by aging, many changes in cognition previously considered the unavoidable consequence of brain senescence may instead result from incremental insults on brain function associated with aging-related medical conditions. The detection of such changes, which may stabilize or even reverse with appropriate intervention, and their differentiation from the cognitive changes associated with neurodegenerative disease or other neurologic disorders is a critical task. The primary goal of this chapter is to describe changes in various cognitive abilities that occur with normal aging and with common age-related medical and neurologic conditions.
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THE EFFECTS OF NORMAL AGING ON COGNITIVE FUNCTION
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General Intellectual Functioning
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Age-related changes in intelligence are extremely variable, with notable interindividual differences. Overall, studies of aging have consistently shown that crystallized abilities (information and skills gained from experience) remain relatively intact with aging, while fluid intelligence, which involves flexible reasoning and problem-solving approaches, declines. This general pattern has been documented in both cross-sectional and longitudinal research designs. More specifically, it has been theorized that reductions ...