Anosognosia predicts default mode network hypometabolism and clinical progression to dementia.

TitleAnosognosia predicts default mode network hypometabolism and clinical progression to dementia.
Publication TypeJournal Article
Year of Publication2018
AuthorsTherriault J, Ng KPin, Pascoal TA, Mathotaarachchi S, Kang MSu, Struyfs H, Shin M, Benedet AL, Walpola IC, Nair V, Gauthier S, Rosa-Neto P
Corporate AuthorsAlzheimer's Disease Neuroimaging Initiative
JournalNeurology
Volume90
Issue11
Paginatione932-e939
Date Published2018 Mar 13
ISSN1526-632X
Abstract

OBJECTIVE: To identify the pathophysiologic mechanisms and clinical significance of anosognosia for cognitive decline in mild cognitive impairment.METHODS: We stratified 468 patients with amnestic mild cognitive impairment into intact and impaired awareness groups, determined by the discrepancy between the patient and the informant score on the Everyday Cognition questionnaire. Voxel-based linear regression models evaluated the associations between self-awareness status and baseline β-amyloid load, measured by [F]florbetapir, and the relationships between awareness status and regional brain glucose metabolism measured by [F]fluorodeoxyglucose at baseline and at 24-month follow-up. Multivariate logistic regression tested the association of awareness status with conversion from amnestic mild cognitive impairment to dementia.RESULTS: We found that participants with impaired awareness had lower [F]fluorodeoxyglucose uptake and increased [F]florbetapir uptake in the posterior cingulate cortex at baseline. In addition, impaired awareness in mild cognitive impairment predicted [F]fluorodeoxyglucose hypometabolism in the posterior cingulate cortex, left basal forebrain, bilateral medial temporal lobes, and right lateral temporal lobe over 24 months. Furthermore, participants with impaired awareness had a nearly 3-fold increase in likelihood of conversion to dementia within a 2-year time frame.CONCLUSIONS: Our results suggest that anosognosia is linked to Alzheimer disease pathophysiology in vulnerable structures, and predicts subsequent hypometabolism in the default mode network, accompanied by an increased risk of progression to dementia. This highlights the importance of assessing awareness of cognitive decline in the clinical evaluation and management of individuals with amnestic mild cognitive impairment.

DOI10.1212/WNL.0000000000005120
Alternate JournalNeurology
PubMed ID29444971
PubMed Central IDPMC5858945

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