Anatomy and White Matter Connections of the Parahippocampal Gyrus

Lin, Yueh‐Hsin; Dhanaraj, Vukshitha; Mackenzie, Alana; Young, Isabella M.; Tanglay, Onur; Briggs, Robert G.; Chakraborty, Arijit; Hormovas, Jorge; Fonseka, R. Dineth; Kim, Sihyong J.; Yeung, Jacky T.; Teo, Charles; Sughrue, Michael E.

doi:10.1016/j.wneu.2020.12.136

Cited by 26 publications

(20 citation statements)

References 74 publications

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“…These tracts connect to GM structures associated with memory function, and WM compromise in these tracts has been associated with increased risk of AD conversion (Fu et al, 2014;Gold et al, 2012;Mielke et al, 2012). In particular, the CHB and ILF tracts are the major connecting fibers of the parahippocampal gyrus (Lin et al, 2021). Our analysis shows that the parahippocampal terminal regions of both of these tracts are compromised in at-risk MCI patients, consistent with previous reports (Mielke et al, 2012;Marcos Dolado et al, 2019).…”

Section: Discussionsupporting

confidence: 89%

Specific White Matter Tracts and Diffusion Properties Predict Conversion From Mild Cognitive Impairment to Alzheimer’s Disease

Stone

Ryman

Hartman

et al. 2021

Front. Aging Neurosci.

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Identifying biomarkers that can assess the risk of developing Alzheimer’s Disease (AD) remains a significant challenge. In this study, we investigated the integrity levels of brain white matter in 34 patients with mild cognitive impairment (MCI) who later converted to AD and 53 stable MCI patients. We used diffusion tensor imaging (DTI) and automated fiber quantification to obtain the diffusion properties of 20 major white matter tracts. To identify which tracts and diffusion measures are most relevant to AD conversion, we used support vector machines (SVMs) to classify the AD conversion and non-conversion MCI patients based on the diffusion properties of each tract individually. We found that diffusivity measures from seven white matter tracts were predictive of AD conversion with axial diffusivity being the most predictive diffusion measure. Additional analyses revealed that white matter changes in the central and parahippocampal terminal regions of the right cingulate hippocampal bundle, central regions of the right inferior frontal occipital fasciculus, and posterior and anterior regions of the left inferior longitudinal fasciculus were the best predictors of conversion from MCI to AD. An SVM based on these white matter tract regions achieved an accuracy of 0.75. These findings provide additional potential biomarkers of AD risk in MCI patients.

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Section: Discussionsupporting

confidence: 89%

Specific White Matter Tracts and Diffusion Properties Predict Conversion From Mild Cognitive Impairment to Alzheimer’s Disease

Stone

Ryman

Hartman

et al. 2021

Front. Aging Neurosci.

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“…H-P regions were an important limbic system in memory and learning, which were closely related to the amygdala encoding emotion ( DiMenichi et al, 2019 ). Recently, a study has found that higher activation of the parahippocampal gyrus was associated with anxiety in patients with first-episode depressive disorder ( Lin et al, 2021 ). In addition, a functional MRI study showed that hippocampal activation was sensitive to different emotional music.…”

Section: Discussionmentioning

confidence: 99%

High-Frequency Hearing Loss Is Associated With Anxiety and Brain Structural Plasticity in Older Adults

Zhang

et al. 2022

Front. Aging Neurosci.

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Age-related hearing loss (ARHL) is a kind of symmetrical and slow sensorineural hearing loss, which is a common condition in older adults. The characteristic of ARHL is hearing loss beginning in the high-frequency region and spreading toward low-frequency with age. Previous studies have linked it to anxiety, suggesting that brain structure may be involved in compensatory plasticity after partial hearing deprivation. However, the neural mechanisms of underlying ARHL-related anxiety remain unclear. The purpose of this cross-sectional study was to explore the interactions among high-frequency hearing loss and anxiety as well as brain structure in older adults. Sixty-seven ARHL patients and 68 normal hearing (NH) controls participated in this study, and the inclusion criterion of ARHL group was four-frequency (0.5, 1, 2, and 4 kHz) pure tone average (PTA) > 25 decibels hearing level of the better hearing ear. All participants performed three-dimensional T1-weighted magnetic resonance imaging (MRI), pure tone audiometry tests, anxiety and depression scales. Our results found gray matter volume (GMV) decreased in 20 brain regions in the ARHL group compared with the NH group, and a positive correlation existed between high-frequency pure tone audiometry (H-PT) and anxiety scores in the ARHL group. Among 20 brain regions, we also found the GMVs of the middle cingulate cortex (MCC), and the hippocampal/parahippocampal (H-P) regions were associated with H-PT and anxiety scores in all participants separately. However, the depressive symptoms indicated no relationship with hearing assessment or GMVs. Our findings revealed that the crucial role of MCC and H-P in a link of anxiety and hearing loss in older adults.

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“…The caudate nucleus participates in cognitive processes by stimulating the correct movement patterns and selecting appropriate secondary targets based on the assessment of the action outcome ( Grahn et al, 2008 ). The parahippocampal gyrus is located in the medial under the occipital and temporal lobes, is the main cortical input to the hippocampus, is considered to play an important role in high cognitive functions including memory coding retrieval and visuospatial processing, and is an important center for memory processing ( Lin et al, 2021 ). This study found that the sALFF in the above two brain regions of SLE patients with CI was higher than that of HCs and SLE patients without CI, respectively, suggesting that the local brain activity intensity of these two brain regions increased, which may be related to the compensation of cognitive dysfunction.…”

Section: Discussionmentioning

confidence: 99%

Dynamic changes of amplitude of low-frequency in systemic lupus erythematosus patients with cognitive impairment

Yang

Zhao²,

Zhang³

et al. 2022

Front. Neurosci.

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BackgroundCognitive dysfunction (CI) is frequently reported in patients with systemic lupus erythematosus (SLE), but the identification and assessment of SLE-related CI remain challenging. Previous studies have focused on changes in static brain activity, and no studies have investigated the characteristics of dynamic brain activity in SLE patients with CI.ObjectsWe calculated the dynamic amplitude of low-frequency fluctuation (dALFF) by combining the ALFF with a sliding window method to assess the temporal variability of brain functional activity in SLE patients with and without CI.MethodsThirty-eight SLE with CI, thirty-eight SLE without CI, and thirty-eight healthy controls (HCs) were recruited. By comparing static ALFF (sALFF) and dALFF among the three groups, changes in brain activity intensity and its temporal variability were assessed in patients with SLE with or without CI. Spearman correlation coefficients were calculated between the brain function indicator and Mini-mental State Examination (MMSE) scores of SLE with CI.ResultsSubjects among the three groups exhibited significant sALFF differences in the right parahippocampal gyrus, left caudate nucleus, right putamen, and left cuneus. Compared to the SLE without CI, the right parahippocampal gyrus exhibited higher sALFF in the SLE with CI group. Compared to the HCs, the left caudate nucleus exhibited increased sALFF in the SLE with CI group. Participants in the three groups exhibited significant dALFF variability in the right parahippocampal gyrus, right lingual gyrus, and bilateral inferior occipital gyrus. Compared to the HCs, the right lingual gyrus exhibited reduced dALFF in the SLE without CI group. Compared to the HCs, the right parahippocampal gyrus exhibited increased dALFF, left calcarine fissure, and the surrounding cortex exhibited reduced dALFF in the SLE with CI group. There was no significant correlation between the MMSE score, sALFF, and dALFF in the SLE with CI group.ConclusionSLE patients with CI have abnormal brain activity intensity and stability. By analyzing the dynamics of intrinsic brain activity, it provides a new idea for evaluating SLE-related CI. However, more research and validation with multiple metrics are needed to determine the link between the severity of cognitive impairment (CI) and brain activity in patients with SLE.

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Anatomy and White Matter Connections of the Parahippocampal Gyrus

Cited by 26 publications

References 74 publications

Specific White Matter Tracts and Diffusion Properties Predict Conversion From Mild Cognitive Impairment to Alzheimer’s Disease

Specific White Matter Tracts and Diffusion Properties Predict Conversion From Mild Cognitive Impairment to Alzheimer’s Disease

High-Frequency Hearing Loss Is Associated With Anxiety and Brain Structural Plasticity in Older Adults

Dynamic changes of amplitude of low-frequency in systemic lupus erythematosus patients with cognitive impairment

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