The Experts below are selected from a list of 5004 Experts worldwide ranked by ideXlab platform
Wendyl Dsouza - One of the best experts on this subject based on the ideXlab platform.
-
Generalized polyspike train an eeg biomarker of drug resistant Idiopathic Generalized Epilepsy
Neurology, 2018Co-Authors: Udaya Seneviratne, Yanping Sun, Piero Perucca, Zhibin Chen, Meng Kee Tan, Terence J Obrien, Wendyl DsouzaAbstract:Objective To identify clinical and EEG biomarkers of drug resistance in adults with Idiopathic Generalized Epilepsy. Methods We conducted a case-control study consisting of a discovery cohort and a replication cohort independently assessed at 2 different centers. In each center, patients with the Idiopathic Generalized Epilepsy phenotype and Generalized spike-wave discharges on EEG were classified as drug-resistant or drug-responsive. EEG changes were classified into predefined patterns and compared between the 2 groups in the discovery cohort. Factors associated with drug resistance in multivariable analysis were tested in the replication cohort. Results The discovery cohort included 85 patients (29% drug-resistant and 71% drug-responsive). Their median age at assessment was 32 years and 50.6% were female. Multivariable analysis showed that higher number of seizure types ever experienced (3 vs 1: odds ratio [OR] = 31.1, 95% confidence interval [CI]: 4.5–214, p Conclusion Generalized polyspike train during sleep may be an EEG biomarker for drug resistance in adults with Idiopathic Generalized Epilepsy.
-
focal abnormalities in Idiopathic Generalized Epilepsy a critical review of the literature
Epilepsia, 2014Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DsouzaAbstract:Summary Conventionally, Epilepsy is dichotomized into distinct “focal” and “Generalized” categories. However, many studies have reported so-called focal features among patients with Idiopathic Generalized Epilepsy (IGE) in the domains of semiology, electroencephalography, neuropsychology, neuropathology, and neuroimaging. We sought to review such features and clinical implications. A Web of Science database search was conducted to identify relevant publications. Our search yielded 145 papers describing focal features involving different domains in IGE, with 117 papers analyzed after excluding abstracts and case reports. Focal semiologic features are commonly seen in IGE. There are conflicting data from studies in the domains of electroencephalography, neuroimaging, and neuropathology. Studies on neuropsychology are suggestive of frontal lobe functional deficits in juvenile myoclonic Epilepsy. Most advanced neuroimaging studies demonstrate the involvement of both the thalamus and the cortex during Generalized spike-wave discharges (GSWDs). A few electroencephalographic and neuroimaging studies indicate that the cortex precedes the thalamus at the onset of GSWD. Focal features may contribute to misdiagnosis of IGE as focal Epilepsy. However there are methodologic limitations in the studies that affect the results. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
-
the prognosis of Idiopathic Generalized Epilepsy
Epilepsia, 2012Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DsouzaAbstract:Summary Prognosis describes the trajectory and long-term outcome of a condition. Most studies indicate a better prognosis in Idiopathic Generalized Epilepsy (IGE) in comparison with other Epilepsy syndromes. Studies looking at the long-term outcome of different IGE syndromes are relatively scant. Childhood absence Epilepsy appears to have a higher rate of remission compared to juvenile absence Epilepsy. In absence epilepsies, development of myoclonus and Generalized tonic–clonic seizures predicts lower likelihood of remission. Although most patients with juvenile myoclonic Epilepsy (JME) achieve remission on antiepileptic drug therapy, <20% appear to remain in remission without treatment. Data on the prognosis of other IGE syndromes are scarce. There are contradictory findings reported on the value of electroencephalography as a predictor of prognosis. Comparisons are made difficult by study heterogeneity, particularly in methodology and diagnostic criteria.
-
the electroencephalogram of Idiopathic Generalized Epilepsy
Epilepsia, 2012Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DsouzaAbstract:Idiopathic Generalized Epilepsy (IGE) is classified into several subsyndromes based on clinical and electroencephalography (EEG) features. The EEG signature of IGE is bisynchronous, symmetric, and Generalized spike-wave complex; although focal, irregular, and so called "fragments" of discharges are not uncommon. Other characteristic EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, and photoparoxysmal response. Both human and animal data suggest involvement of the thalamus and the cortex in the generation of spike-wave discharges in IGE. Circadian variations of Generalized epileptiform discharges are well described, and these can be useful in diagnostic confirmation. Those discharges tend to occur more often after awakening and during cyclic alternating pattern phase-A of non-rapid eye movement sleep. Activation procedures such as hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are useful techniques to increase the yield of both interictal and ictal EEG abnormalities. Although not in routine use, specific triggers such as pattern stimulation and cognitive tasks may also be of value in eliciting rare reflex seizure-related EEG abnormalities. Variations of EEG abnormalities are evident between different electroclinical syndromes. EEG is also affected by certain external as well as internal factors, which should be borne in mind when interpreting EEG studies in IGE.
Qing Jiao - One of the best experts on this subject based on the ideXlab platform.
-
frequency specific alterations of local synchronization in Idiopathic Generalized Epilepsy
Medicine, 2015Co-Authors: Jue Wang, Zhiqiang Zhang, Zhengge Wang, Yu-feng Zang, Qing Jiao, Yubin Huang, Fang Yang, Wei LiaoAbstract:Recurrently and abnormally hypersynchronous discharge is a striking feature of Idiopathic Generalized Epilepsy (IGE). Resting-state functional magnetic resonance imaging has revealed aberrant spontaneous brain synchronization, predominately in low-frequency range ( 0.073 Hz) in a “conscious perception network,” which is anchored by the pregenual and dorsal anterior cingulate cortex, as well as the bilateral insular cortices, possibly contributing to impaired consciousness. Furthermore, we found frequency-specific alternating local synchronization in the posterior portion of the DMN relative to the anterior part, suggesting an interaction between the disease and frequency bands. Importantly, the aberrant high-frequency local synchronization in the middle cingulate cortex was associated with disease duration, thus linking BOLD frequency changes to disease severity. These findings provide an overview of frequency-specific local synchronization of BOLD fluctuations, and may be helpful in uncovering abnormal synchronous neuronal activity in patients with IGE at specific frequency bands.
-
impairments of thalamic nuclei in Idiopathic Generalized Epilepsy revealed by a study combining morphological and functional connectivity mri
PLOS ONE, 2012Co-Authors: Zhengge Wang, Zhiqiang Zhang, Wei Liao, Guanghui Chen, Qing Jiao, Kangjian Sun, Lianfang Shen, Maoxue Wang, Yijun LiuAbstract:Objective Neuroimaging evidence suggested that the thalamic nuclei may play different roles in the progress of Idiopathic Generalized Epilepsy (IGE). This study aimed to demonstrate the alterations in morphometry and functional connectivity in the thalamic nuclei in IGE.
-
altered functional structural coupling of large scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Hucheng Chen, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
-
Altered functional–structural coupling of large-scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, He-sheng Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
-
Altered functional-structural coupling of large-scale brain networks in Idiopathic Generalized Epilepsy.
Brain : a journal of neurology, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, Huafu Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic-clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic-clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic-clonic seizures.
Zhiqiang Zhang - One of the best experts on this subject based on the ideXlab platform.
-
frequency specific alterations of local synchronization in Idiopathic Generalized Epilepsy
Medicine, 2015Co-Authors: Jue Wang, Zhiqiang Zhang, Zhengge Wang, Yu-feng Zang, Qing Jiao, Yubin Huang, Fang Yang, Wei LiaoAbstract:Recurrently and abnormally hypersynchronous discharge is a striking feature of Idiopathic Generalized Epilepsy (IGE). Resting-state functional magnetic resonance imaging has revealed aberrant spontaneous brain synchronization, predominately in low-frequency range ( 0.073 Hz) in a “conscious perception network,” which is anchored by the pregenual and dorsal anterior cingulate cortex, as well as the bilateral insular cortices, possibly contributing to impaired consciousness. Furthermore, we found frequency-specific alternating local synchronization in the posterior portion of the DMN relative to the anterior part, suggesting an interaction between the disease and frequency bands. Importantly, the aberrant high-frequency local synchronization in the middle cingulate cortex was associated with disease duration, thus linking BOLD frequency changes to disease severity. These findings provide an overview of frequency-specific local synchronization of BOLD fluctuations, and may be helpful in uncovering abnormal synchronous neuronal activity in patients with IGE at specific frequency bands.
-
Identifying Corticothalamic Network Epicenters in Patients with Idiopathic Generalized Epilepsy
AJNR. American journal of neuroradiology, 2015Co-Authors: Zhiqiang Zhang, Zhengge Wang, Jue Wang, Q. Jiao, F. Yang, Qifu Tan, G. Chen, Yu-feng ZangAbstract:BACKGROUND AND PURPOSE: Corticothalamic networks are considered core pathologic substrates for Idiopathic Generalized Epilepsy; however, the predominant epileptogenic epicenters within these networks are still largely unknown. The current study aims to identify these epicenters by resting-state functional connectivity. MATERIALS AND METHODS: To identify epicenters within the corticothalamic networks in Idiopathic Generalized Epilepsy, we retrospectively studied a large cohort of patients with this condition (n = 97) along with healthy controls (n = 123) by resting-state functional MR imaging. The thalamus was functionally divided into subregions corresponding to distinct cortical lobes for 5 parallel corticothalamic networks. The functional connectivity between each voxel in the cortical lobe and the corresponding thalamic subregion was calculated, and functional connectivity strength was used to evaluate the interconnectivity of voxels in the cortex and thalamus. RESULTS: The projection of 5 cortical lobes to the thalamus is consistent with previous histologic findings in humans. Compared with controls, patients with Idiopathic Generalized Epilepsy showed increased functional connectivity strength in 4 corticothalamic networks: 1) the supplementary motor area, pulvinar, and ventral anterior nucleus in the prefrontal-thalamic network; 2) the premotor cortex and ventrolateral nucleus in motor/premotor-thalamic networks; 3) the visual cortex, posterior default mode regions, and pulvinar in parietal/occipital-thalamic networks; and 4) the middle temporal gyrus in the temporal-thalamic network. CONCLUSIONS: Several key nodes were distinguished in 4 corticothalamic networks. The identification of these epicenters refines the corticothalamic network theory and provides insight into the pathophysiology of Idiopathic Generalized Epilepsy.
-
impairments of thalamic nuclei in Idiopathic Generalized Epilepsy revealed by a study combining morphological and functional connectivity mri
PLOS ONE, 2012Co-Authors: Zhengge Wang, Zhiqiang Zhang, Wei Liao, Guanghui Chen, Qing Jiao, Kangjian Sun, Lianfang Shen, Maoxue Wang, Yijun LiuAbstract:Objective Neuroimaging evidence suggested that the thalamic nuclei may play different roles in the progress of Idiopathic Generalized Epilepsy (IGE). This study aimed to demonstrate the alterations in morphometry and functional connectivity in the thalamic nuclei in IGE.
-
altered functional structural coupling of large scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Hucheng Chen, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
-
Altered functional–structural coupling of large-scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, He-sheng Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
Wei Liao - One of the best experts on this subject based on the ideXlab platform.
-
frequency specific alterations of local synchronization in Idiopathic Generalized Epilepsy
Medicine, 2015Co-Authors: Jue Wang, Zhiqiang Zhang, Zhengge Wang, Yu-feng Zang, Qing Jiao, Yubin Huang, Fang Yang, Wei LiaoAbstract:Recurrently and abnormally hypersynchronous discharge is a striking feature of Idiopathic Generalized Epilepsy (IGE). Resting-state functional magnetic resonance imaging has revealed aberrant spontaneous brain synchronization, predominately in low-frequency range ( 0.073 Hz) in a “conscious perception network,” which is anchored by the pregenual and dorsal anterior cingulate cortex, as well as the bilateral insular cortices, possibly contributing to impaired consciousness. Furthermore, we found frequency-specific alternating local synchronization in the posterior portion of the DMN relative to the anterior part, suggesting an interaction between the disease and frequency bands. Importantly, the aberrant high-frequency local synchronization in the middle cingulate cortex was associated with disease duration, thus linking BOLD frequency changes to disease severity. These findings provide an overview of frequency-specific local synchronization of BOLD fluctuations, and may be helpful in uncovering abnormal synchronous neuronal activity in patients with IGE at specific frequency bands.
-
impairments of thalamic nuclei in Idiopathic Generalized Epilepsy revealed by a study combining morphological and functional connectivity mri
PLOS ONE, 2012Co-Authors: Zhengge Wang, Zhiqiang Zhang, Wei Liao, Guanghui Chen, Qing Jiao, Kangjian Sun, Lianfang Shen, Maoxue Wang, Yijun LiuAbstract:Objective Neuroimaging evidence suggested that the thalamic nuclei may play different roles in the progress of Idiopathic Generalized Epilepsy (IGE). This study aimed to demonstrate the alterations in morphometry and functional connectivity in the thalamic nuclei in IGE.
-
resting state basal ganglia network in Idiopathic Generalized Epilepsy
Human Brain Mapping, 2012Co-Authors: Cheng Luo, Wei Liao, Yang Xia, Xu Lei, Kaiqing Xue, Zhiping Yao, Youxiu Lai, Eduardo Marti Nezmontes, Dong Zhou, Pedro A ValdessosaAbstract:r Abstract: The basal ganglia, a brain structure related to motor control, is implicated in the modulation of epileptic discharges generalization in patients with Idiopathic Generalized Epilepsy (IGE). Using group independent component analysis (ICA) on resting-state fMRI data, this study identified a resting state functional network that predominantly consisted of the basal ganglia in both healthy controls and patients with IGE. In order to gain a better understanding of the basal ganglia network(BGN) in IGE patients, we compared the BGN functional connectivity of controls with that of Epilepsy patients, ei- ther with interictal epileptic discharges (with-discharge period, WDP) or without epileptic discharge (nondischarge period, NDP) while scanning. Compared with controls, functional connectivity of BGN in IGE patients demonstrated significantly more integration within BGN except cerebellum and supple- mentary motor area (SMA) during both periods. Compared with the NDP group, the increased func- tional connectivity was found in bilateral caudate nucleus and the putamen, and decreases were observed in the bilateral cerebellum and SMA in WDP group. In accord with the proposal that the ba- sal ganglia modulates epileptic discharge activity, the results showed that the modulation enhanced the integration in BGN of patients, and modulation during WDP was stronger than that during NDP. Furthermore, reduction of functional connectivity in cerebellum and SMA, the abnormality might be further aggravated during WDP, was consistent with the behavioral manifestations with disturbed motor function in IGE. These resting-state fMRI findings in the current study provided evidence confirming the role of the BGN as an important modulator in IGE. Hum Brain Mapp 33:1279-1294, 2012. V C 2011 Wiley Periodicals, Inc.
-
altered functional structural coupling of large scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Hucheng Chen, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
-
Altered functional–structural coupling of large-scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, He-sheng Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
Zhengge Wang - One of the best experts on this subject based on the ideXlab platform.
-
frequency specific alterations of local synchronization in Idiopathic Generalized Epilepsy
Medicine, 2015Co-Authors: Jue Wang, Zhiqiang Zhang, Zhengge Wang, Yu-feng Zang, Qing Jiao, Yubin Huang, Fang Yang, Wei LiaoAbstract:Recurrently and abnormally hypersynchronous discharge is a striking feature of Idiopathic Generalized Epilepsy (IGE). Resting-state functional magnetic resonance imaging has revealed aberrant spontaneous brain synchronization, predominately in low-frequency range ( 0.073 Hz) in a “conscious perception network,” which is anchored by the pregenual and dorsal anterior cingulate cortex, as well as the bilateral insular cortices, possibly contributing to impaired consciousness. Furthermore, we found frequency-specific alternating local synchronization in the posterior portion of the DMN relative to the anterior part, suggesting an interaction between the disease and frequency bands. Importantly, the aberrant high-frequency local synchronization in the middle cingulate cortex was associated with disease duration, thus linking BOLD frequency changes to disease severity. These findings provide an overview of frequency-specific local synchronization of BOLD fluctuations, and may be helpful in uncovering abnormal synchronous neuronal activity in patients with IGE at specific frequency bands.
-
Identifying Corticothalamic Network Epicenters in Patients with Idiopathic Generalized Epilepsy
AJNR. American journal of neuroradiology, 2015Co-Authors: Zhiqiang Zhang, Zhengge Wang, Jue Wang, Q. Jiao, F. Yang, Qifu Tan, G. Chen, Yu-feng ZangAbstract:BACKGROUND AND PURPOSE: Corticothalamic networks are considered core pathologic substrates for Idiopathic Generalized Epilepsy; however, the predominant epileptogenic epicenters within these networks are still largely unknown. The current study aims to identify these epicenters by resting-state functional connectivity. MATERIALS AND METHODS: To identify epicenters within the corticothalamic networks in Idiopathic Generalized Epilepsy, we retrospectively studied a large cohort of patients with this condition (n = 97) along with healthy controls (n = 123) by resting-state functional MR imaging. The thalamus was functionally divided into subregions corresponding to distinct cortical lobes for 5 parallel corticothalamic networks. The functional connectivity between each voxel in the cortical lobe and the corresponding thalamic subregion was calculated, and functional connectivity strength was used to evaluate the interconnectivity of voxels in the cortex and thalamus. RESULTS: The projection of 5 cortical lobes to the thalamus is consistent with previous histologic findings in humans. Compared with controls, patients with Idiopathic Generalized Epilepsy showed increased functional connectivity strength in 4 corticothalamic networks: 1) the supplementary motor area, pulvinar, and ventral anterior nucleus in the prefrontal-thalamic network; 2) the premotor cortex and ventrolateral nucleus in motor/premotor-thalamic networks; 3) the visual cortex, posterior default mode regions, and pulvinar in parietal/occipital-thalamic networks; and 4) the middle temporal gyrus in the temporal-thalamic network. CONCLUSIONS: Several key nodes were distinguished in 4 corticothalamic networks. The identification of these epicenters refines the corticothalamic network theory and provides insight into the pathophysiology of Idiopathic Generalized Epilepsy.
-
impairments of thalamic nuclei in Idiopathic Generalized Epilepsy revealed by a study combining morphological and functional connectivity mri
PLOS ONE, 2012Co-Authors: Zhengge Wang, Zhiqiang Zhang, Wei Liao, Guanghui Chen, Qing Jiao, Kangjian Sun, Lianfang Shen, Maoxue Wang, Yijun LiuAbstract:Objective Neuroimaging evidence suggested that the thalamic nuclei may play different roles in the progress of Idiopathic Generalized Epilepsy (IGE). This study aimed to demonstrate the alterations in morphometry and functional connectivity in the thalamic nuclei in IGE.
-
altered functional structural coupling of large scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Hucheng Chen, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
-
Altered functional–structural coupling of large-scale brain networks in Idiopathic Generalized Epilepsy
Brain, 2011Co-Authors: Zhiqiang Zhang, Zhengge Wang, Wei Liao, Dante Mantini, Jurong Ding, Cuiping Yuan, Guanghui Chen, He-sheng Chen, Qing JiaoAbstract:The human brain is a large-scale integrated network in the functional and structural domain. Graph theoretical analysis provides a novel framework for analysing such complex networks. While previous neuroimaging studies have uncovered abnormalities in several specific brain networks in patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures, little is known about changes in whole-brain functional and structural connectivity networks. Regarding functional and structural connectivity, networks are intimately related and share common small-world topological features. We predict that patients with Idiopathic Generalized Epilepsy would exhibit a decoupling between functional and structural networks. In this study, 26 patients with Idiopathic Generalized Epilepsy characterized by tonic–clonic seizures and 26 age- and sex-matched healthy controls were recruited. Resting-state functional magnetic resonance imaging signal correlations and diffusion tensor image tractography were used to generate functional and structural connectivity networks. Graph theoretical analysis revealed that the patients lost optimal topological organization in both functional and structural connectivity networks. Moreover, the patients showed significant increases in nodal topological characteristics in several cortical and subcortical regions, including mesial frontal cortex, putamen, thalamus and amygdala relative to controls, supporting the hypothesis that regions playing important roles in the pathogenesis of Epilepsy may display abnormal hub properties in network analysis. Relative to controls, patients showed further decreases in nodal topological characteristics in areas of the default mode network, such as the posterior cingulate gyrus and inferior temporal gyrus. Most importantly, the degree of coupling between functional and structural connectivity networks was decreased, and exhibited a negative correlation with Epilepsy duration in patients. Our findings suggest that the decoupling of functional and structural connectivity may reflect the progress of long-term impairment in Idiopathic Generalized Epilepsy, and may be used as a potential biomarker to detect subtle brain abnormalities in Epilepsy. Overall, our results demonstrate for the first time that Idiopathic Generalized Epilepsy is reflected in a disrupted topological organization in large-scale brain functional and structural networks, thus providing valuable information for better understanding the pathophysiological mechanisms of Generalized tonic–clonic seizures. * Abbreviations : AAL : automated anatomical labelling GTCS : Generalized tonic–clonic seizures IGE : Idiopathic Generalized Epilepsy
