The existence of cognitive plateaus in Alzheimer's disease

Andrea C. Bozoki, Hyonggin An, Eva S. Bozoki, Roderick J. Little

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Background: The objective of this study was to evaluate the existence of cognitive plateaus in some individuals during the course of Alzheimer's disease (AD). Methods: Data came from the historical patient group collected via the Consortium to Establish a Registry for Alzheimer's Disease (CERAD, Duke University, 1988-1996). Data reduction was performed by using principal components analysis to derive a single cognitive measure (F1), followed by application of a novel plateau-searching algorithm to individual patient data, looking for stable periods of 3 years or longer. To evaluate the time dependence of F1, we fitted a linear mixed model to the group and to individual data points. Results: Twenty-two percent of AD subjects (54/243) and 98% of healthy control subjects (253/258) exhibited a plateau. Within the AD plateau group, the most common pattern was a single plateau (mean, 3.6 years; range, 3 to 7 years) that extended for the entire measurement period (28/54 subjects). Briefer plateau durations were seen at the beginning or end of the measurement period. Initial cognitive function (F1) was slightly higher in the plateau group, which was also slightly older and less well-educated. Men and women were equally represented. Conclusions: In a patient sample predating the widespread use of cholinesterase inhibitors, we found that approximately one fifth of individuals with AD demonstrated periods of prolonged cognitive stability. This significant interindividual variability must be considered when providing prognostic information to families and when assessing individual patient responses to pharmacotherapy. We advise caution when assessing results of potentially disease-modifying agents at the individual patient level.

Original languageEnglish
Pages (from-to)470-478
Number of pages9
JournalAlzheimer's and Dementia
Volume5
Issue number6
DOIs
Publication statusPublished - 2009 Nov 1

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Alzheimer Disease
Cholinesterase Inhibitors
Principal Component Analysis
Cognition
Registries
Linear Models
Healthy Volunteers
Drug Therapy

Keywords

  • Alzheimer's disease
  • Cognition
  • Dementia
  • Neuropsychology

ASJC Scopus subject areas

  • Health Policy
  • Epidemiology
  • Geriatrics and Gerontology
  • Psychiatry and Mental health
  • Cellular and Molecular Neuroscience
  • Developmental Neuroscience
  • Clinical Neurology

Cite this

The existence of cognitive plateaus in Alzheimer's disease. / Bozoki, Andrea C.; An, Hyonggin; Bozoki, Eva S.; Little, Roderick J.

In: Alzheimer's and Dementia, Vol. 5, No. 6, 01.11.2009, p. 470-478.

Research output: Contribution to journalArticle

Bozoki, Andrea C. ; An, Hyonggin ; Bozoki, Eva S. ; Little, Roderick J. / The existence of cognitive plateaus in Alzheimer's disease. In: Alzheimer's and Dementia. 2009 ; Vol. 5, No. 6. pp. 470-478.
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