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S5‐02–06: Motor signs in aging, mild cognitive impairment and Alzheimer's disease
Author(s) -
Louis Elan D.
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.570
Subject(s) - dementia , disease , medicine , physical medicine and rehabilitation , population , cognition , cognitive decline , cognitive impairment , psychology , neuroscience , pathology , environmental health
older subjects have shown that dementia is often not the result of a single disease, but rather the result of mixed pathologies. Because Alzheimer’s disease (AD) is the most common clinical dementia in older persons, it follows that clinical AD, and possibly amnestic mild cognitive impairment (aMCI), the earliest clinical stage of AD, may also be pathologically heterogeneous disorders. The objective of this talk is to review and investigate the role of mixed pathologies in community-dwelling persons with dementia, probable AD and MCI. Methods: Briefly review the evidence for mixed pathologies in dementia, probable AD and MCI. In a new study, we used deceased and autopsied subjects from the Rush Religious Orders Study and the Memory and Aging Project, longitudinal community-based clinical-pathologic studies to investigate the pathology of participants with probable AD and MCI at the time of death. The clinical diagnosis of probable AD used NINCDS-ARDA criteria. MCI was defined as neuropsychologic impairment without a clinical diagnosis of dementia. Those with episodic memory impairment were designated as aMCI. We examined the neuropathologic diagnosis of AD (NIA-Reagan Criteria), macrosocopic cerebral infarcts, and Lewy body (LB) disease and calculated “pure” and mixed diagnoses. Results: There is increasing evidence for mixed pathologies in dementia, but little data is available on the pathology of probable AD and MCI in community-dwelling older subjects. In this new study the majority of persons with a clinical diagnosis of probable AD had sufficient AD pathology to confirm the diagnosis; however, most also had evidence of mixed pathologies, most commonly AD with cerebral infarcts. Persons with MCI also commonly had AD and mixed pathologies. Both AD and mixed pathologies were more common in those with aMCI, whereas vascular cognitive impairment without AD was more common in naMCI. Conclusions: Clinically diagnosed probable AD is a pathologically heterogeneous disorder. Mixed pathologies including AD and cerebral infarcts, and less commonly AD and Lewy bodies account for most of this heterogeneity. Mixed pathologies are commonly evident in aMCI, the earliest clinical stage of probable AD.