Abstract Details

Title Cognitive Changes in Normal Older Individuals Precede Clinical Symptom Onset in Mild Cognitive Impairment

Topic Aging and Dementia

Presentation(s) P07 - (-)

Poster/Presentation
Number 147

Objective

Background BACKGROUND: Some older individuals who are cognitively normal have Alzheimer's disease (AD) pathologies based on brain autopsy findings and amyloid imaging studies. Such individuals are hypothesized to be at high risk for developing cognitive decline over time, and at some point during this 'pre-clinical' phase of disease, decline in cognitive performance may become evident, even though clinical symptoms are not reported.

Design/Methods DESIGN/METHODS: Annual longitudinal neuropsychological and clinical assessments were completed in 349 participants who were cognitively normal at baseline, some with first-degree relatives with AD. Consensus diagnoses were completed annually to determine whether participants remained normal or had developed cognitive decline, consistent with a clinical diagnosis of MCI or dementia. Cox regression analyses were performed in 268 of these individuals, with baseline test scores and time-dependent-rate-of-change in scores as covariates (adjusted by baseline age and education), using age at onset of clinical symptoms as the outcome variable.

Results RESULTS: The baseline mean age of the cohort was 57.2 years. The mean time from baseline to onset of clinical symptoms was 6.2 years. Increased risk of progressing from normal cognition to onset of clinical symptoms was associated with lower baseline scores on several cognitive tests, including tests of episodic memory and processing speed (p<0.001). Additionally, the rate of decline in multiple cognitive measures was differentially greater in individuals who were subsequently diagnosed with MCI (p<0.001).

Conclusions CONCLUSIONS: Cognitive performance declines at least 6 years prior to the onset of clinical symptoms and signs that warrant a diagnosis of MCI. Subtle yet measurable cognitive changes are evident during a pre-clinical phase of AD.

Authors/Disclosures
Ned C. Sacktor, MD, FAAN PRESENTER	No disclosure on file
Ola A. Selnes, PhD (Cognitive Neuroscience)	No disclosure on file
	No disclosure on file
Rebecca F. Gottesman, MD, PhD (Johns Hopkins University)	The institution of Dr. Gottesman has received research support from NIH.
Anthony J. Furlan, MD, FAAN (Cleveland Medical Center)	No disclosure on file
Guy M. McKhann, MD (Columbia University)	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
R S. Turner, MD, PhD, FAAN (Georgetown University)	Dr. Turner has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Re:Cognition Health.
	No disclosure on file
	No disclosure on file
	No disclosure on file
Marilyn Albert (Johns Hopkins School of Medicine)	Marilyn Albert has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Marilyn Albert has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Eli Lilly. Marilyn Albert has received personal compensation in the range of $500-$4,999 for serving as a Chair with Global Council on Brain Health.

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