Increased Intrinsic Connectivity of the Default Mode Network in Temporal Lobe Epilepsy: Evidence from Resting-State MEG Recordings

Hsiao, Fu Jung; Yu, Hsiang‐Yu; Chen, Wei Ta; Kwan, Shang Yeong; Chien, Chen Fu; Yen, Der Jen; Yiu, Chun Hing; Shih, Yang Hsin; Lin, Yung Yang

doi:10.1371/journal.pone.0128787

Cited by 58 publications

(53 citation statements)

References 97 publications

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“…Another study using simultaneous EEG and functional MRI found that AEDs resistance and uncontrolled seizures are associated with a greater reduction in DMN connectivity than epilepsy alone, which suggests the alteration of DMN might be useful as a biomarker for treatment resistance [23]. In addition, another previous study using resting state functional MRI also suggested that the connectivity within the DMN is reinforced during spike-free periods [24]. All of these previous reports, in line with our present findings, suggest the alterations of DMN regions in patients with GGE.…”

Section: Discussionmentioning

confidence: 97%

Brain Morphology in Patients with Genetic Generalized Epilepsy: Its Heterogeneity among Subsyndromes

et al. 2018

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Background: We aimed to evaluate the brain morphology of patients with genetic generalized epilepsy (GGE) compared to healthy subjects. In addition, we investigated whether there are differences in brain morphology among different GGE syndromes. Methods: We enrolled 100 patients with a clinical diagnosis of GGE. The patients were classified into different syndrome groups according to their predominant seizure type, age of seizure onset, and electroencephalography characteristics (12 childhood absence epilepsy [AE], 13 juvenile AE, 56 juvenile myoclonic epilepsy, and 19 epilepsy with generalized tonic-clonic alone). We used surface-based morphometry of brain magnetic resonance imaging to evaluate brain morphology. Results: We found significantly widespread alterations of brain morphology, including cortical thickness and volumes in several regions in the patients with GGE compared to healthy controls. In addition, we observed significant differences in alterations of cortical thickness and volumes among the different GGE syndromes. However, there were no differences in cortical surface areas between the patients with GGE and healthy controls. There was a significantly negative correlation between the duration of epilepsy and most of the each measures of abnormal brain morphology. Conclusions: The main finding of this study is that brain morphology in patients with GGE is significantly different from that in healthy controls. In addition, we found that the different GGE syndromes show distinct structural brain morphology, especially cortical thickness, which can help us understand the pathogenesis of GGE syndromes.

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Section: Discussionmentioning

confidence: 97%

Brain Morphology in Patients with Genetic Generalized Epilepsy: Its Heterogeneity among Subsyndromes

et al. 2018

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“…However, IC is still a widely used technique for revealing altered FC and has been applied in cases of brain tumors [56], brain lesions [57], and other disorders. In addition, in source-level network analyses, the IC has been suggested to effectively represent the true coupling of two brain regions with a nonzero time delay using MEG data [31,58]. Thus, we used the IC method to calculate the FC matrix for each subject in the source space.…”

Section: Discussionmentioning

confidence: 99%

“…Studies have shown that asymmetric and slow activity of the delta band (1-4 Hz) can reliably lateralize to the epileptogenic hemisphere [14,[60][61][62]. Indeed, significant differences in delta band activity were found between TLE patients and controls in network analyses [31,63,64]. Thus, we only selected one frequency band, the delta band, as our frequency band of interest.…”

Section: Complexitymentioning

confidence: 99%

“…Based on both structural and functional connectivity (FC) analyses, accumulating evidence suggests that brain-networks in TLE patients are pathologically altered [27][28][29][30]. Hsiao et al [31] investigated FC alterations in the default mode network (DMN) in TLE, using resting-state spike-free MEG recordings. Their results revealed that TLE involved changes in FC within the DMN and that the change was associated with the lateralization of TLE.…”

Section: Introductionmentioning

confidence: 99%

“…Their results revealed that TLE involved changes in FC within the DMN and that the change was associated with the lateralization of TLE. In right TLE, FC between the DMN and the right medial temporal region is enhanced, while left TLE involves enhanced FC between the DMN and bilateral medial temporal regions [31]. By analyzing resting-state MEG signals, Jin et al [32] calculated betweenness centrality at the source-level functional network in mesial TLE.…”

Section: Introductionmentioning

confidence: 99%

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Automatic Lateralization of Temporal Lobe Epilepsy Based on MEG Network Features Using Support Vector Machines

Chen

et al. 2018

Complexity

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Correct lateralization of temporal lobe epilepsy (TLE) is critical for improving surgical outcomes. As a relatively new noninvasive clinical recording system, magnetoencephalography (MEG) has rarely been applied for determining lateralization of unilateral TLE. Here we propose a framework for using resting-state brain-network features and support vector machine (SVM) for TLE lateralization based on MEG. We recruited 15 patients with left TLE, 15 patients with right TLE, and 15 age-and sex-matched healthy controls. The lateralization problem was then transferred into a series of binary classification problems, including left TLE versus healthy control, right TLE versus healthy control, and left TLE versus right TLE. Brain-network features were extracted for each participant using three network metrics (nodal degree, betweenness centrality, and nodal efficiency). A radial basis function kernel SVM (RBF-SVM) was employed as the classifier. The leave-one-subject-out cross-validation strategy was used to test the ability of this approach to overcome individual differences. The results revealed that the nodal degree performed best for left TLE versus healthy control and right TLE versus healthy control, with accuracy of 80.76% and 75.00%, respectively. Betweenness centrality performed best for left TLE versus right TLE with an accuracy of 88.10%. The proposed approach demonstrated that MEG is a good candidate for solving the lateralization problem in unilateral TLE using various brain-network features.

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Resting‐state brain entropy in right temporal lobe epilepsy and its relationship with alertness

et al. 2019

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BackgroundTo date, no functional MRI (fMRI) studies have focused on brain entropy in right temporal lobe epilepsy (rTLE) patients. Here, we characterized brain entropy (BEN) alterations in patients with rTLE using resting‐state functional MRI(rs‐fMRI) and explored the relationship between BEN and alertness.MethodThirty‐one rTLE patients and 33 controls underwent MRI scanning to investigate differences in BEN and resting‐state functional connectivity (rs‐FC) in regions of interest (ROIs) between patients and controls. Correlation analyses were performed to examine relationships between the BEN of each ROI and alertness reaction times (RTs) in rTLE patients.ResultsCompared with controls, the BEN of rTLE patients was significantly increased in the right middle temporal gyrus, inferior temporal gyrus, and other regions of the left hemisphere and significantly decreased in the right middle frontal gyrus and left supplementary motor area (p < .05). The rs‐FCs between the ROIs (at p < .01, with the left superior parietal lobule and right precentral gyrus defined as ROI1 and ROI2, respectively) and the whole brain showed an increasing trend in rTLE patients. In addition, the BEN of ROI2 was associated with the intrinsic alertness and phasic alertness RTs of patients with rTLE.ConclusionsOur findings suggest that BEN is altered in patients with rTLE and that decreased BEN in the right precentral gyrus is positively related to intrinsic and phasic alertness; the abnormal FC in the brain regions with altered entropy suggests a reconstruction of brain functional connectivity. These findings suggest that BEN mapping may provide a useful tool for probing brain mechanisms related to TLE.

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Increased Intrinsic Connectivity of the Default Mode Network in Temporal Lobe Epilepsy: Evidence from Resting-State MEG Recordings

Cited by 58 publications

References 97 publications

Brain Morphology in Patients with Genetic Generalized Epilepsy: Its Heterogeneity among Subsyndromes

Brain Morphology in Patients with Genetic Generalized Epilepsy: Its Heterogeneity among Subsyndromes

Automatic Lateralization of Temporal Lobe Epilepsy Based on MEG Network Features Using Support Vector Machines

Resting‐state brain entropy in right temporal lobe epilepsy and its relationship with alertness

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