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. 2020 May 14;12(1):57.
doi: 10.1186/s13195-020-00626-1.

The meta-memory ratio: a new cohort-independent way to measure cognitive awareness in asymptomatic individuals at risk for Alzheimer's disease

Geoffroy Gagliardi  1   2 , Marion Houot  3   4 , Federica Cacciamani  5   3   6 , Marie-Odile Habert  7   8   9 , Bruno Dubois  5   3   4 , Stéphane Epelbaum  5   3   6 ; for ADNI; for the INSIGHT-preAD study group
Collaborators, Affiliations

The meta-memory ratio: a new cohort-independent way to measure cognitive awareness in asymptomatic individuals at risk for Alzheimer's disease

Geoffroy Gagliardi et al. Alzheimers Res Ther. .

Abstract

Background: Lack of awareness of cognitive decline (ACD) has been described at the preclinical and prodromal stages of Alzheimer's disease (AD). In this study, we introduced a meta-memory ratio (MMR) and explored how it is associated with neuroimaging AD biomarkers in asymptomatic individuals at risk for AD.

Method: Four hundred forty-eight cognitively healthy participants from two cohorts of subjective memory complainers (INSIGHT-PreAD and ADNI) were included. Regression models were used to assess the impact of AD biomarkers on the MMR.

Result: In both cohorts, there was a significant quadratic effect of cerebral amyloidosis on the MMR value. In particular, participants had a high ACD up to the amyloid positivity threshold, above which a decrease of ACD was eventually observed as the amyloid load increased.

Conclusion: This nonlinear evolution of ACD in very early AD must be taken into account in clinical care and for trial enrollment as well.

Keywords: Alzheimer’s disease; Awareness; Preclinical.

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Conflict of interest statement

MO Habert has received honoraria as expert for Blue Earth company.

S Epelbaum received honoraria as consultant and/or speaker on behalf of Eli-Lilly, Roche, Biogen, Astelas Pharma, and GE Healthcare.

B Dubois reports personal fees from Boehringer-Ingelheim, personal fees from Eli-Lilly, grants from Roche, and grants from Merck, outside the submitted work.

The authors have no conflict of interest to report.

Figures

Fig. 1
Fig. 1
MMR’s construction
Fig. 2
Fig. 2
Comparison of the relative effect of biomarkers by cohort. MMR, meta-memory ratio; FDG mean metabolism, computed using FDG-AD ROIs
Fig. 3
Fig. 3
Effect of biomarkers on MMR score
See this image and copyright information in PMC

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