Structural and Functional Abnormalities of Olfactory-Related Regions in Subjective Cognitive Decline, Mild Cognitive Impairment, and Alzheimer’s Disease

作者：Ben Chen, Qiang Wang, Xiaomei Zhong, Naikeng Mai, Min Zhang, Huarong Zhou, Antje Haehner, Xinru Chen, Zhangying Wu, Lavinia Albéri, D. C. Rao, Wentao Liu, Jinhong Zheng, Li‐Jing Lin, Nan‐Xi Li, Sihao Chen, Bingxin Chen, Thomas Hummel, Yuping Ning · 发表于：The International Journal of Neuropsychopharmacology · 年份：2021 · DOI：10.1093/ijnp/pyab091 · 被引用次数：58 · 研究领域：Olfactory and Sensory Function Studies、Neurological Disease Mechanisms and Treatments、Advanced Chemical Sensor Technologies

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: Stru...