{"title":"Structural Abnormalities of Olfactory-Related Brain Regions in Mild Cognitive Impairment and Subjective Cognitive Decline Individuals.","authors":"Lujiang Zhan, Guanxiong Tan, Jia Dong, Zhengdong Deng, Yunfeng Zou, Zhiyong Dan, Ruixia Wang, Zhengli Luo, Xingxing Zhu","doi":"10.1177/08919887251336464","DOIUrl":null,"url":null,"abstract":"<p><p>BackgroundOlfactory impairment might be already present at the subjective cognitive impairment (SCD) individuals, and deepens with disease severity in the Alzheimer's disease (AD) spectrum. However, the neuroanatomical correlates of olfactory impairment in SCD individuals are not fully elucidated.MethodsA hundred and twenty enrolled older adults without dementia (25 healthy controls (HCs), 45 SCD individuals and 50 mild cognitive impairment (MCI) individuals) completed olfactory assessment and structural magnetic resonance imaging (MRI) scanning. Olfactory function was evaluated by the 16-item Sniffin' Sticks odor identification test (SSIT). Region of interest (ROI) analysis was conducted for the gray matter volume (GMV) of 8 olfactory-related brain regions.ResultsIn ROI analysis, from HC, SCD to MCI group, smaller GMV of olfactory-related regions and olfactory impairment became increasingly severe. For HC group, olfactory impairment was only associated with smaller entorhinal cortex (<i>P</i> < 0.05). In SCD individuals, reduced GMVs of entorhinal cortex and hippocampus were associated with olfactory impairment (<i>P</i> < 0.05). In MCI individuals, decreased GMVs of piriform cortex, amygdala, entorhinal cortex, orbitofrontal cortex, hippocampus and parahippocampus were significantly associated with olfactory impairment (<i>P</i> < 0.05).ConclusionsThe atrophy of olfactory-related brain regions gradually increased and the corresponding olfactory function gradually decreased in older adults of HC, SCD and MCI. The olfactory regions associated with olfactory impairment in SCD individuals were mainly in entorhinal cortex and hippocampus.</p>","PeriodicalId":16028,"journal":{"name":"Journal of Geriatric Psychiatry and Neurology","volume":" ","pages":"8919887251336464"},"PeriodicalIF":2.9000,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geriatric Psychiatry and Neurology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1177/08919887251336464","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CLINICAL NEUROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
BackgroundOlfactory impairment might be already present at the subjective cognitive impairment (SCD) individuals, and deepens with disease severity in the Alzheimer's disease (AD) spectrum. However, the neuroanatomical correlates of olfactory impairment in SCD individuals are not fully elucidated.MethodsA hundred and twenty enrolled older adults without dementia (25 healthy controls (HCs), 45 SCD individuals and 50 mild cognitive impairment (MCI) individuals) completed olfactory assessment and structural magnetic resonance imaging (MRI) scanning. Olfactory function was evaluated by the 16-item Sniffin' Sticks odor identification test (SSIT). Region of interest (ROI) analysis was conducted for the gray matter volume (GMV) of 8 olfactory-related brain regions.ResultsIn ROI analysis, from HC, SCD to MCI group, smaller GMV of olfactory-related regions and olfactory impairment became increasingly severe. For HC group, olfactory impairment was only associated with smaller entorhinal cortex (P < 0.05). In SCD individuals, reduced GMVs of entorhinal cortex and hippocampus were associated with olfactory impairment (P < 0.05). In MCI individuals, decreased GMVs of piriform cortex, amygdala, entorhinal cortex, orbitofrontal cortex, hippocampus and parahippocampus were significantly associated with olfactory impairment (P < 0.05).ConclusionsThe atrophy of olfactory-related brain regions gradually increased and the corresponding olfactory function gradually decreased in older adults of HC, SCD and MCI. The olfactory regions associated with olfactory impairment in SCD individuals were mainly in entorhinal cortex and hippocampus.
期刊介绍:
Journal of Geriatric Psychiatry and Neurology (JGP) brings together original research, clinical reviews, and timely case reports on neuropsychiatric care of aging patients, including age-related biologic, neurologic, and psychiatric illnesses; psychosocial problems; forensic issues; and family care. The journal offers the latest peer-reviewed information on cognitive, mood, anxiety, addictive, and sleep disorders in older patients, as well as tested diagnostic tools and therapies.