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Resting state functional connectivity differences between behavioral variant frontotemporal dementia and Alzheimer's disease.

Hafkemeijer A, Möller C, Dopper EG, Jiskoot LC, Schouten TM, van Swieten JC, van der Flier WM, Vrenken H, Pijnenburg YA, Barkhof F, Scheltens P, van der Grond J, Rombouts SA - Front Hum Neurosci (2015)

Bottom Line: Given gray matter differences, we observed decreased network-to-region connectivity in bvFTD between (a) lateral visual cortical network and lateral occipital and cuneal cortex, and (b) auditory system network and angular gyrus.In AD, we found decreased network-to-region connectivity between the dorsal visual stream network and lateral occipital and parietal opercular cortex.Region-to-region connectivity was decreased in bvFTD between superior temporal gyrus and cuneal, supracalcarine, intracalcarine cortex, and lingual gyrus.

View Article: PubMed Central - PubMed

Affiliation: Department of Methodology and Statistics, Institute of Psychology, Leiden University Leiden, Netherlands ; Department of Radiology, Leiden University Medical Center Leiden, Netherlands ; Leiden Institute for Brain and Cognition, Leiden University Leiden, Netherlands.

ABSTRACT

Introduction: Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are the most common types of early-onset dementia. Early differentiation between both types of dementia may be challenging due to heterogeneity and overlap of symptoms. Here, we apply resting state functional magnetic resonance imaging (fMRI) to study functional brain connectivity differences between AD and bvFTD.

Methods: We used resting state fMRI data of 31 AD patients, 25 bvFTD patients, and 29 controls from two centers specialized in dementia. We studied functional connectivity throughout the entire brain, applying two different analysis techniques, studying network-to-region and region-to-region connectivity. A general linear model approach was used to study group differences, while controlling for physiological noise, age, gender, study center, and regional gray matter volume.

Results: Given gray matter differences, we observed decreased network-to-region connectivity in bvFTD between (a) lateral visual cortical network and lateral occipital and cuneal cortex, and (b) auditory system network and angular gyrus. In AD, we found decreased network-to-region connectivity between the dorsal visual stream network and lateral occipital and parietal opercular cortex. Region-to-region connectivity was decreased in bvFTD between superior temporal gyrus and cuneal, supracalcarine, intracalcarine cortex, and lingual gyrus.

Conclusion: We showed that the pathophysiology of functional brain connectivity is different between AD and bvFTD. Our findings support the hypothesis that resting state fMRI shows disease-specific functional connectivity differences and is useful to elucidate the pathophysiology of AD and bvFTD. However, the group differences in functional connectivity are less abundant than has been shown in previous studies.

No MeSH data available.


Related in: MedlinePlus

Functional connectivity in bvFTD vs. AD: network-to-region connectivity. Differences in functional connectivity between green networks and blue voxels in behavioral variant frontotemporal dementia (FTD) and Alzheimer's disease (AD) (TFCE, FWE-corrected). (A) Decreased functional connectivity between lateral visual cortical network (green) and lateral occipital cortex and cuneal cortex (blue) in bvFTD compared with AD. (B) Decreased functional connectivity between dorsal visual stream network (green) and lateral occipital cortex and parietal opercular cortex (blue) in AD compared with bvFTD. (C) Less negative functional connectivity between auditory system network (green) and angular gyrus (blue) in bvFTD compared with AD. Images are overlaid on the MNI-152 standard anatomical image. (D) Subjects' mean z scores were extracted from brain areas with group differences in functional connectivity (blue areas). Boxplots show median, lower, and upper quartile, and sample minimum and maximum z scores for patients with AD, patients with bvFTD, and healthy controls (HC, dotted lines).
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Figure 2: Functional connectivity in bvFTD vs. AD: network-to-region connectivity. Differences in functional connectivity between green networks and blue voxels in behavioral variant frontotemporal dementia (FTD) and Alzheimer's disease (AD) (TFCE, FWE-corrected). (A) Decreased functional connectivity between lateral visual cortical network (green) and lateral occipital cortex and cuneal cortex (blue) in bvFTD compared with AD. (B) Decreased functional connectivity between dorsal visual stream network (green) and lateral occipital cortex and parietal opercular cortex (blue) in AD compared with bvFTD. (C) Less negative functional connectivity between auditory system network (green) and angular gyrus (blue) in bvFTD compared with AD. Images are overlaid on the MNI-152 standard anatomical image. (D) Subjects' mean z scores were extracted from brain areas with group differences in functional connectivity (blue areas). Boxplots show median, lower, and upper quartile, and sample minimum and maximum z scores for patients with AD, patients with bvFTD, and healthy controls (HC, dotted lines).

Mentions: The results of post-hoc testing showed decreased functional connectivity in bvFTD compared with AD between network II (lateral visual cortical network) and the lateral occipital cortex and cuneal cortex (Table 2, Figure 2A). Patients with AD showed decreased functional connectivity between network VIII (dorsal visual stream network) and lateral occipital cortex and parietal opercular cortex (Table 2, Figure 2B). We also observed “negative” (i.e., anti-correlated) connectivity: bvFTD patients showed less negative functional connectivity between network III (auditory system network) and the angular gyrus (Table 2, Figure 2C).


Resting state functional connectivity differences between behavioral variant frontotemporal dementia and Alzheimer's disease.

Hafkemeijer A, Möller C, Dopper EG, Jiskoot LC, Schouten TM, van Swieten JC, van der Flier WM, Vrenken H, Pijnenburg YA, Barkhof F, Scheltens P, van der Grond J, Rombouts SA - Front Hum Neurosci (2015)

Functional connectivity in bvFTD vs. AD: network-to-region connectivity. Differences in functional connectivity between green networks and blue voxels in behavioral variant frontotemporal dementia (FTD) and Alzheimer's disease (AD) (TFCE, FWE-corrected). (A) Decreased functional connectivity between lateral visual cortical network (green) and lateral occipital cortex and cuneal cortex (blue) in bvFTD compared with AD. (B) Decreased functional connectivity between dorsal visual stream network (green) and lateral occipital cortex and parietal opercular cortex (blue) in AD compared with bvFTD. (C) Less negative functional connectivity between auditory system network (green) and angular gyrus (blue) in bvFTD compared with AD. Images are overlaid on the MNI-152 standard anatomical image. (D) Subjects' mean z scores were extracted from brain areas with group differences in functional connectivity (blue areas). Boxplots show median, lower, and upper quartile, and sample minimum and maximum z scores for patients with AD, patients with bvFTD, and healthy controls (HC, dotted lines).
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Figure 2: Functional connectivity in bvFTD vs. AD: network-to-region connectivity. Differences in functional connectivity between green networks and blue voxels in behavioral variant frontotemporal dementia (FTD) and Alzheimer's disease (AD) (TFCE, FWE-corrected). (A) Decreased functional connectivity between lateral visual cortical network (green) and lateral occipital cortex and cuneal cortex (blue) in bvFTD compared with AD. (B) Decreased functional connectivity between dorsal visual stream network (green) and lateral occipital cortex and parietal opercular cortex (blue) in AD compared with bvFTD. (C) Less negative functional connectivity between auditory system network (green) and angular gyrus (blue) in bvFTD compared with AD. Images are overlaid on the MNI-152 standard anatomical image. (D) Subjects' mean z scores were extracted from brain areas with group differences in functional connectivity (blue areas). Boxplots show median, lower, and upper quartile, and sample minimum and maximum z scores for patients with AD, patients with bvFTD, and healthy controls (HC, dotted lines).
Mentions: The results of post-hoc testing showed decreased functional connectivity in bvFTD compared with AD between network II (lateral visual cortical network) and the lateral occipital cortex and cuneal cortex (Table 2, Figure 2A). Patients with AD showed decreased functional connectivity between network VIII (dorsal visual stream network) and lateral occipital cortex and parietal opercular cortex (Table 2, Figure 2B). We also observed “negative” (i.e., anti-correlated) connectivity: bvFTD patients showed less negative functional connectivity between network III (auditory system network) and the angular gyrus (Table 2, Figure 2C).

Bottom Line: Given gray matter differences, we observed decreased network-to-region connectivity in bvFTD between (a) lateral visual cortical network and lateral occipital and cuneal cortex, and (b) auditory system network and angular gyrus.In AD, we found decreased network-to-region connectivity between the dorsal visual stream network and lateral occipital and parietal opercular cortex.Region-to-region connectivity was decreased in bvFTD between superior temporal gyrus and cuneal, supracalcarine, intracalcarine cortex, and lingual gyrus.

View Article: PubMed Central - PubMed

Affiliation: Department of Methodology and Statistics, Institute of Psychology, Leiden University Leiden, Netherlands ; Department of Radiology, Leiden University Medical Center Leiden, Netherlands ; Leiden Institute for Brain and Cognition, Leiden University Leiden, Netherlands.

ABSTRACT

Introduction: Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are the most common types of early-onset dementia. Early differentiation between both types of dementia may be challenging due to heterogeneity and overlap of symptoms. Here, we apply resting state functional magnetic resonance imaging (fMRI) to study functional brain connectivity differences between AD and bvFTD.

Methods: We used resting state fMRI data of 31 AD patients, 25 bvFTD patients, and 29 controls from two centers specialized in dementia. We studied functional connectivity throughout the entire brain, applying two different analysis techniques, studying network-to-region and region-to-region connectivity. A general linear model approach was used to study group differences, while controlling for physiological noise, age, gender, study center, and regional gray matter volume.

Results: Given gray matter differences, we observed decreased network-to-region connectivity in bvFTD between (a) lateral visual cortical network and lateral occipital and cuneal cortex, and (b) auditory system network and angular gyrus. In AD, we found decreased network-to-region connectivity between the dorsal visual stream network and lateral occipital and parietal opercular cortex. Region-to-region connectivity was decreased in bvFTD between superior temporal gyrus and cuneal, supracalcarine, intracalcarine cortex, and lingual gyrus.

Conclusion: We showed that the pathophysiology of functional brain connectivity is different between AD and bvFTD. Our findings support the hypothesis that resting state fMRI shows disease-specific functional connectivity differences and is useful to elucidate the pathophysiology of AD and bvFTD. However, the group differences in functional connectivity are less abundant than has been shown in previous studies.

No MeSH data available.


Related in: MedlinePlus