Gray matter volume reduction in the emotional brain networks in adults with anosmia

Lee, Suji; Kim, Jungyoon; Kim, Bong Jik; Kim, Rye Young; Ha, Eunji; Kim, Shinhye; Hong, Seung No; Lyoo, In Kyoon; Kim, Dae Woo

doi:10.1002/jnr.25037

Cited by 4 publications

(9 citation statements)

References 47 publications

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“…That is, middle‐aged to older adults with lower gray matter volume in medial temporal cortex also had lower orbitofrontal gray matter volume. A similar image analysis approach was taken in a study of anosmia in which a pattern of medial temporal gray matter volume was observed, with the gray matter volume within this structural network differing between controls and anosmics 47 . Our results are also partially consistent with evidence that odorant identification, and not detection threshold, was significantly associated with orbitofrontal gray matter volume in older adults with mild cognitive impairment 48 .…”

Section: Discussionsupporting

confidence: 83%

“…A similar image analysis approach was taken in a study of anosmia in which a pattern of medial temporal gray matter volume was observed, with the gray matter volume within this structural network differing between controls and anosmics. 47 Our results are also partially consistent with evidence that odorant identification, and not detection threshold, was significantly associated with orbitofrontal gray matter volume in older adults with mild cognitive impairment. 48 Thus, there is replication of medial temporal and orbitofrontal associations with olfactory function across studies when using a similar analysis approach and when considering memory-related declines.…”

Section: Gray Matter Effectssupporting

confidence: 88%

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Gray matter and episodic memory associations with olfaction in middle‐aged to older adults

Eckert,

Benitez,

Soler

et al. 2023

Int Forum Allergy Rhinol

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BackgroundAge‐related declines in olfaction contribute to low quality of life and appear to occur with declines in cognitive function, including diminished episodic memory. We tested the hypothesis that low gray matter volume within cortical regions that support olfaction and episodic memory can explain age‐related differences in olfactory and episodic memory functions.MethodsT1‐weighted images, Sniffin’ Sticks olfactory measures, and the NIH Toolbox‐Cognition Battery were administered to 131 middle‐aged to older adults (50–86 years; 66% female). Correlation was used to examine the associations between these measures. A network‐based image processing approach was then used to examine the degree to which spatial patterns of gray matter variance were related to the olfactory and cognitive measures. Structural equation modeling was used to characterize the relative specificity of olfactory, cognitive, gray matter, and aging associations.ResultsOlfactory threshold, discrimination, and identification exhibited small to medium effect size associations with episodic memory performance (rs = 0.27–0.42, ps < 0.002). Gray matter volume within medial temporal and orbitofrontal cortex was also related to olfactory (discrimination and identification) and episodic memory function (rs = 0.21–0.36, ps < 0.019). Age and episodic memory explained the same variance in olfaction that was explained by the medial temporal and orbitofrontal pattern of gray matter volume.ConclusionsThe results of this cross‐sectional study suggest that identifying mechanisms contributing to differences in medial temporal and orbitofrontal cortex will advance our understanding of co‐morbid olfactory and cognitive declines.

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Section: Discussionsupporting

confidence: 83%

Section: Gray Matter Effectssupporting

confidence: 88%

Gray matter and episodic memory associations with olfaction in middle‐aged to older adults

Eckert,

Benitez,

Soler

et al. 2023

Int Forum Allergy Rhinol

View full text Add to dashboard Cite

show abstract

“…In alignment with prior research [ 21 , 23 ], the ICA output was configured to 10 components. Each component was subject to thresholding at z=3.0, preserving only the voxels contributing significantly to the component.…”

Section: Methodsmentioning

confidence: 99%

“…Recognizing that brain regions are interconnected both structurally and functionally, disease-related atrophy often appears within networks of highly correlated regions rather than a single isolated anatomical structure [ 17 , 18 ]. Imaging the networks of brain regions with structural correlations can provide insights into disease-specific pathologies at the network level [ 17 - 24 ]. Moreover, the multivariate network-based analysis employs a model-free approach, negating the need for pre-selected regions [ 22 , 25 ].…”

Section: Introductionmentioning

confidence: 99%

Alterations in Brain Morphometric Networks and Their Relationship with Memory Dysfunction in Patients with Type 2 Diabetes Mellitus

Kim,

Joo,

et al. 2024

Exp Neurobiol

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Cognitive dysfunction, a significant complication of type 2 diabetes mellitus (T2DM), can potentially manifest even from the early stages of the disease. Despite evidence of global brain atrophy and related cognitive dysfunction in early-stage T2DM patients, specific regions vulnerable to these changes have not yet been identified. The study enrolled patients with T2DM of less than five years’ duration and without chronic complications (T2DM group, n=100) and demographically similar healthy controls (control group, n=50). High-resolution T1-weighted magnetic resonance imaging data were subjected to independent component analysis to identify structurally significant components indicative of morphometric networks. Within these networks, the groups’ gray matter volumes were compared, and distinctions in memory performance were assessed. In the T2DM group, the relationship between changes in gray matter volume within these networks and declines in memory performance was examined. Among the identified morphometric networks, the T2DM group exhibited reduced gray matter volumes in both the precuneus (Bonferroni-corrected p=0.003) and insular-opercular (Bonferroni-corrected p=0.024) networks relative to the control group. Patients with T2DM demonstrated significantly lower memory performance than the control group (p=0.001). In the T2DM group, reductions in gray matter volume in both the precuneus ( r =0.316, p=0.001) and insular-opercular ( r =0.199, p=0.047) networks were correlated with diminished memory performance. Our findings indicate that structural alterations in the precuneus and insular-opercular networks, along with memory dysfunction, can manifest within the first 5 years following a diagnosis of T2DM.

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“…Previous neuroimaging studies, including our own [ 8 ], have demonstrated the structural brain alterations associated with anosmia [ 3 , 9 ]. These studies have focused on regions within both the primary olfactory network, such as the olfactory cortex, amygdala, and entorhinal cortex, and the secondary olfactory network, including the orbitofrontal cortex [ 3 , 9 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

Changes in Structural Covariance among Olfactory-related Brain Regions in Anosmia Patients

Lee,

Song,

Hong

et al. 2024

Exp Neurobiol

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Anosmia, characterized by the loss of smell, is associated not only with dysfunction in the peripheral olfactory system but also with changes in several brain regions involved in olfactory processing. Specifically, the orbitofrontal cortex is recognized for its pivotal role in integrating olfactory information, engaging in bidirectional communication with the primary olfactory regions, including the olfactory cortex, amygdala, and entorhinal cortex. However, little is known about alterations in structural connections among these brain regions in patients with anosmia. In this study, high-resolution T1-weighted images were obtained from participants. Utilizing the volumes of key brain regions implicated in olfactory function, we employed a structural covariance approach to investigate brain reorganization patterns in patients with anosmia (n=22) compared to healthy individuals (n=30). Our structural covariance analysis demonstrated diminished connectivity between the amygdala and entorhinal cortex, components of the primary olfactory network, in patients with anosmia compared to healthy individuals (z=-2.22, FDR-corrected p=0.039). Conversely, connectivity between the orbitofrontal cortex—a major region in the extended olfactory network—and amygdala was found to be enhanced in the anosmia group compared to healthy individuals (z=2.32, FDR-corrected p=0.039). However, the structural connections between the orbitofrontal cortex and entorhinal cortex did not differ significantly between the groups (z=0.04, FDR-corrected p=0.968). These findings suggest a potential structural reorganization, particularly of higher-order cortical regions, possibly as a compensatory effort to interpret the limited olfactory information available in individuals with olfactory loss.

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Gray matter volume reduction in the emotional brain networks in adults with anosmia

Cited by 4 publications

References 47 publications

Gray matter and episodic memory associations with olfaction in middle‐aged to older adults

Gray matter and episodic memory associations with olfaction in middle‐aged to older adults

Alterations in Brain Morphometric Networks and Their Relationship with Memory Dysfunction in Patients with Type 2 Diabetes Mellitus

Changes in Structural Covariance among Olfactory-related Brain Regions in Anosmia Patients

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