The Neuroanatomic Correlates of Olfactory Identification Impairment in Healthy Older Adults and in Persons with Mild Cognitive Impairment
Year: 2022
Type: article
Abstract: BACKGROUND: Olfactory identification (OI) impairment appears early in the course of Alzheimer's disease dementia (AD), prior to detectable cognitive impairment. However, the neuroanatomical correlates of impaired OI in cognitively normal older adults (CN) and persons with mild cognitive impairment (MCI) are not fully understood. OBJECTIVE: We examined the neuroanatomic correlates of OI impairment in older adults from the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS). METHODS: Our sample included 1,600 older adults without dementia who completed clinical assessment and structural brain imaging from 2011 to 2013. We characterized OI impairment using the 12-item Sniffin' Sticks odor identification test (score ≤6). We used voxel-based morphometry (VBM) and region of interest (ROI) analyses to examine the neuroanatomic correlates of impaired OI in CN and MCI, after adjusting for potential confounders. Analyses were also separately stratified by race and sex. RESULTS: In CN, OI impairment was associated with smaller amygdala gray matter (GM) volume (p < 0.05). In MCI, OI impairment was associated with smaller GM volumes of the olfactory cortex, amygdala, entorhinal cortex, hippocampus, and insula (ps < 0.05). Differential associations were observed by sex in MCI; OI impairment was associated with lower insular GM volumes among men but not among women (p-interaction = 0.04). There were no meaningful interactions by race. CONCLUSION: The brain regions associated with OI impairment in individuals without dementia are specifically those regions known to be the primary targets of AD pathogenic processes. These findings highlight the potential utility of olfactory assessment in the identification and stratification of older adults at risk for AD.
Source: Journal of Alzheimer s Disease
DOI: 10.3233/jad-220228
Institutions: Johns Hopkins University, Johns Hopkins Medicine, Mayo Clinic, Michigan State University, Columbia University Irving Medical Center, University of Mississippi Medical Center, University of Mississippi, National Institutes of Health, National Institute of Neurological Disorders and Stroke, University of Pennsylvania
Language: English
Subfield: Sensory Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
Funders: U.S. Department of Defense, U.S. Department of Health and Human Services, Mayo Clinic, Eli Lilly and Company, Biogen, University of Southern California, Eisai, National Institutes of Health, Avid Radiopharmaceuticals, National Institute on Aging, National Heart, Lung, and Blood Institute, National Institute on Deafness and Other Communication Disorders, National Institute of Neurological Disorders and Stroke, National Center for Advancing Translational Sciences
Awards: G1114307781, G1173125533, G1201667161, G1262629770, G1304508731, G1328425623, G140664742, G1522370804, G1589692941, ARIC Neurocognitive Study (ARIC-NCS) Renewal, G165438358, G1788514665, G1823732541, G1942032999, Imaging small blood and lymphatic vessel abnormalities of the olfactory system in schizophrenia, G2117773213, Institute for Clinical and Translational Research, G2195207551, G2262505034, G2383388692, G2468260354, G2568281471, G2607172802, G2655192887, G2701926366, G293741327, G3103017843, G3329506677, G3744596180, G3935527841, G3973572274, G4068323944, G4230684217, G4290615481, G4597579782, ARIC Neurocognitive Study (ARIC-NCS) Renewal UNC 4 of 5, G4739409156, G4747441672, G4790942633, G4845182219, Advanced MR Imaging of Olfactory Impairment in Prodromal Alzheimer's Disease, ARIC Neurocognitive Study (ARIC-NCS) Renewal 4 of 5, G5023962947, G5330437387, G5352314984, G5364873420, G5464419710, G5556898879, G5622883882, G5770678025, G583528397, G5928944960, G5981726443, G5999060983, G6060132884, G6322445267, G6483657930, G6594067713, G6739173425, ARIC Neurocognitive Study (ARIC-NCS) Renewal 2 of 5, ARIC Neurocognitive Study (ARIC-NCS), G6837735701, G6863459535, G6978868085, G706815212, G7132376052, G7155745631, G7535686976, The ARIC and Neurocognitive Longitudinal Study, G7799800877, G7806539067, G7808459314, G8738262636, G8951135482, G8976278160, G899128061, G9000038488, G9000053661, G9000071824, G9000074502, G9000165945, G9000267281, G901665369, G968738093, G979295734
OpenAlex ID: W4285803877