Structural and Functional Abnormalities of Olfactory-Related Regions in Subjective Cognitive Decline, Mild Cognitive Impairment, and Alzheimer's Disease
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
BACKGROUND: Odor identification (OI) dysfunction is an early marker of Alzheimer's disease (AD), but it remains unclear how olfactory-related regions change from stages of subjective cognitive decline (SCD) and mild cognitive impairment (MCI) to AD dementia.
METHODS: Two hundred and sixty-nine individuals were recruited in the present study. The olfactory-related regions were defined as the regions of interest, and the grey matter volume (GMV), low-frequency fluctuation, regional homogeneity (ReHo), and functional connectivity (FC) were compared for exploring the changing pattern of structural and functional abnormalities across AD, MCI, SCD, and normal controls.
RESULTS: From the SCD, MCI to AD groups, the reduced GMV, increased low-frequency fluctuation, increased ReHo, and reduced FC of olfactory-related regions became increasingly severe, and only the degree of reduced GMV of hippocampus and caudate nucleus clearly distinguished the 3 groups. SCD participants exhibited reduced GMV (hippocampus, etc.), increased ReHo (caudate nucleus), and reduced FC (hippocampus-hippocampus and hippocampus-parahippocampus) in olfactory-related regions compared with normal controls. Additionally, reduced GMV of the bilateral hippocampus and increased ReHo of the right caudate nucleus were associated with OI dysfunction and global cognitive impairment, and they exhibited partially mediated effects on the relationships between OI and global cognition across all participants.
CONCLUSION: Structural and functional abnormalities of olfactory-related regions present early with SCD and deepen with disease severity in the AD spectrum. The hippocampus and caudate nucleus may be the hub joining OI and cognitive function in the AD spectrum.
Details
Original language | English |
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Pages (from-to) | 361-374 |
Number of pages | 14 |
Journal | International Journal of Neuropsychopharmacology |
Volume | 25 |
Issue number | 5 |
Publication status | Published - 27 May 2022 |
Peer-reviewed | Yes |
External IDs
PubMedCentral | PMC9154279 |
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Scopus | 85131219712 |
unpaywall | 10.1093/ijnp/pyab091 |
Mendeley | 3ecdeeef-5dcf-3db8-9c79-a0874133389c |
ORCID | /0000-0001-9713-0183/work/146645260 |
ORCID | /0000-0003-1311-8000/work/158767510 |
Keywords
Sustainable Development Goals
ASJC Scopus subject areas
Keywords
- Alzheimer Disease/diagnostic imaging, Cognitive Dysfunction/diagnostic imaging, Gray Matter/diagnostic imaging, Hippocampus, Humans, Magnetic Resonance Imaging, subjective cognitive decline, MRI, odor identification, caudate nucleus, hippocampus, mild cognitive impairment, Alzheimer's disease