Aβ and cognitive change: examining the preclinical and prodromal stages of Alzheimer's disease

Yen Ying Lim; Paul Maruff; Robert H Pietrzak; Kathryn A Ellis; David Darby; David Ames; Karra Harrington; Ralph N Martins; Colin L Masters; Cassandra Szoeke; Greg Savage; Victor L Villemagne; Christopher C Rowe; AIBL Research Group

doi:10.1016/j.jalz.2013.11.005

Aβ and cognitive change: examining the preclinical and prodromal stages of Alzheimer's disease

Alzheimers Dement. 2014 Nov;10(6):743-751.e1. doi: 10.1016/j.jalz.2013.11.005. Epub 2014 Feb 28.

Authors

Affiliations

¹ The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia. Electronic address: yen_ying_lim@brown.edu.
² The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; CogState Ltd., Melbourne, Victoria, Australia.
³ Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
⁴ The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, Kew, Victoria, Australia; National Ageing Research Institute, Parkville, Victoria, Australia.
⁵ The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.
⁶ Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, Kew, Victoria, Australia; National Ageing Research Institute, Parkville, Victoria, Australia.
⁷ Centre of Excellence for Alzheimer's Disease Research and Care, School of Exercise, Biomedical, and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia.
⁸ The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; National Ageing Research Institute, Parkville, Victoria, Australia; CSIRO Preventative Health Flagship, Parkville, Victoria, Australia.
⁹ Department of Psychology and ARC Centre of Excellence in Cognition and Its Disorders, Macquarie University, Sydney, New South Wales, Australia.
¹⁰ The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Victoria, Australia; Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, Australia.
¹¹ Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Victoria, Australia; Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, Australia.

PMID: 24589436
DOI: 10.1016/j.jalz.2013.11.005

Abstract

Background: High β-amyloid (Aβ) is associated with faster memory decline in healthy individuals and adults with mild cognitive impairment (MCI). However, longer prospective studies are required to determine if Aβ-related memory decline continues and whether it is associated with increased rate of disease progression.

Methods: Healthy controls (HCs; n = 177) and adults with MCI (n = 48) underwent neuroimaging for Aβ and cognitive assessment at baseline. Cognition was reassessed 18 and 36 months later.

Results: Compared with low-Aβ HCs, high-Aβ HC and MCI groups showed moderate decline in episodic and working memory over 36 months. Those with MCI with low Aβ did not show any cognitive decline. Rates of disease progression were increased in the high-Aβ HC and MCI groups.

Conclusions: In healthy individuals, high Aβ likely indicates that Alzheimer's disease (AD)-related neurodegeneration has begun. Once commenced, the rate of decline in cognitive function remains constant across the preclinical and prodromal stages of AD.

Keywords: Aβ; Cognitive decline; Neuropsychology; Preclinical AD; Prodromal AD.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Aged, 80 and over
Alzheimer Disease / complications*
Alzheimer Disease / diagnostic imaging
Amyloid beta-Peptides / metabolism*
Aniline Compounds
Cognition Disorders / diagnosis*
Cognition Disorders / diagnostic imaging
Cognition Disorders / etiology*
Disease Progression
Female
Follow-Up Studies
Humans
Learning
Linear Models
Male
Memory Disorders / etiology*
Memory, Short-Term
Neuropsychological Tests
Positron-Emission Tomography
Prodromal Symptoms*
Psychiatric Status Rating Scales
Thiazoles

Substances

2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole
Amyloid beta-Peptides
Aniline Compounds
Thiazoles