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Shi K, Yu L, Wang Y, Li Z, Li C, Long Q, Zheng J. Impaired interhemispheric synchrony and effective connectivity in right temporal lobe epilepsy. Neurol Sci 2024; 45:2211-2221. [PMID: 38038810 DOI: 10.1007/s10072-023-07198-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 11/09/2023] [Indexed: 12/02/2023]
Abstract
BACKGROUND The brain functional network plays a crucial role in cognitive impairment in temporal lobe epilepsy (TLE). Based on voxel-mirrored homotopic connectivity (VMHC), this study explored how directed functional connectivity changes and is associated with impaired cognition in right TLE (rTLE). METHODS Twenty-seven patients with rTLE and twenty-seven healthy controls were included to perform VMHC and Granger causality analysis (GCA). Correlation analysis was performed based on GCA and cognitive function. RESULTS Bilateral middle frontal gyrus (MFG), middle temporal gyrus, dorsolateral superior frontal gyrus (SFGdor), and supramarginal gyrus (SMG) exhibited decreased VMHC values in the rTLE group. Brain regions with altered VMHC had abnormal directed functional connectivity with multiple brain regions, mainly belonging to the default mode network, sensorimotor network, and visual network. Besides, the Montreal Cognitive Assessment (MoCA) score was positively correlated with the connectivity from the left SFGdor to the right cerebellum crus2 and was negatively correlated with the connectivity from the left SMG to the right supplementary motor area (SMA) before correction. Before correction, both phasic and intrinsic alertness reaction time were positively correlated with the connectivity from the left MFG to the left precentral gyrus (PreCG), connectivity from the left SMG to the right PreCG, and the connectivity from the left SMG to the right SMA. The executive control effect reaction time was positively correlated with the connectivity from the left MFG to the left calcarine fissure surrounding cortex before correction. CONCLUSION The disordered functional network tended to be correlated with cognition impairment in rTLE.
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Affiliation(s)
- Ke Shi
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Lu Yu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Yiling Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zhekun Li
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chunyan Li
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Qijia Long
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jinou Zheng
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China.
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Bartoňová M, Tournier JD, Bartoň M, Říha P, Vojtíšek L, Mareček R, Doležalová I, Rektor I. White matter alterations in MR-negative temporal and frontal lobe epilepsy using fixel-based analysis. Sci Rep 2023; 13:19. [PMID: 36593331 PMCID: PMC9807578 DOI: 10.1038/s41598-022-27233-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023] Open
Abstract
This study focuses on white matter alterations in pharmacoresistant epilepsy patients with no visible lesions in the temporal and frontal lobes on clinical MRI (i.e. MR-negative) with lesions confirmed by resective surgery. The aim of the study was to extend the knowledge about group-specific neuropathology in MR-negative epilepsy. We used the fixel-based analysis (FBA) that overcomes the limitations of traditional diffusion tensor image analysis, mainly within-voxel averaging of multiple crossing fibres. Group-wise comparisons of fixel parameters between healthy controls (N = 100) and: (1) frontal lobe epilepsy (FLE) patients (N = 9); (2) temporal lobe epilepsy (TLE) patients (N = 13) were performed. A significant decrease of the cross-section area of the fixels in the superior longitudinal fasciculus was observed in the FLE. Results in TLE reflected widespread atrophy of limbic, thalamic, and cortico-striatal connections and tracts directly connected to the temporal lobe (such as the anterior commissure, inferior fronto-occipital fasciculus, uncinate fasciculus, splenium of corpus callosum, and cingulum bundle). Alterations were also observed in extratemporal connections (brainstem connection, commissural fibres, and parts of the superior longitudinal fasciculus). To our knowledge, this is the first study to use an advanced FBA method not only on the datasets of MR-negative TLE patients, but also MR-negative FLE patients, uncovering new common tract-specific alterations on the group level.
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Affiliation(s)
- Michaela Bartoňová
- grid.10267.320000 0001 2194 0956Central European Institute of Technology (CEITEC), Multimodal and Functional Neuroimaging Research Group, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic ,grid.10267.320000 0001 2194 0956Brno Epilepsy Center, First Department of Neurology, St. Anne’s University Hospital, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Jacques-Donald Tournier
- grid.13097.3c0000 0001 2322 6764Centre for Medical Engineering, King’s College London, London, UK ,grid.13097.3c0000 0001 2322 6764Centre for the Developing Brain, King’s College London, London, UK
| | - Marek Bartoň
- grid.10267.320000 0001 2194 0956Central European Institute of Technology (CEITEC), Multimodal and Functional Neuroimaging Research Group, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Pavel Říha
- grid.10267.320000 0001 2194 0956Central European Institute of Technology (CEITEC), Multimodal and Functional Neuroimaging Research Group, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic ,grid.10267.320000 0001 2194 0956Brno Epilepsy Center, First Department of Neurology, St. Anne’s University Hospital, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lubomír Vojtíšek
- grid.10267.320000 0001 2194 0956Central European Institute of Technology (CEITEC), Multimodal and Functional Neuroimaging Research Group, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Radek Mareček
- grid.10267.320000 0001 2194 0956Central European Institute of Technology (CEITEC), Multimodal and Functional Neuroimaging Research Group, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Irena Doležalová
- grid.10267.320000 0001 2194 0956Brno Epilepsy Center, First Department of Neurology, St. Anne’s University Hospital, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Ivan Rektor
- grid.10267.320000 0001 2194 0956Central European Institute of Technology (CEITEC), Multimodal and Functional Neuroimaging Research Group, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic ,grid.10267.320000 0001 2194 0956Brno Epilepsy Center, First Department of Neurology, St. Anne’s University Hospital, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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Li Y, Wang J, Wang X, Chen Q, Qin B, Chen J. Reconfiguration of static and dynamic thalamo-cortical network functional connectivity of epileptic children with generalized tonic-clonic seizures. Front Neurosci 2022; 16:953356. [PMID: 35937891 PMCID: PMC9353948 DOI: 10.3389/fnins.2022.953356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/24/2022] [Indexed: 12/05/2022] Open
Abstract
Objective A number of studies in adults and children with generalized tonic-clonic seizure (GTCS) have reported the alterations in morphometry, functional activity, and functional connectivity (FC) in the thalamus. However, the neural mechanisms underlying the alterations in the thalamus of patients with GTCS are not well understood, particularly in children. The aim of the current study was to explore the temporal properties of functional pathways connecting thalamus in children with GTCS. Methods Here, we recruited 24 children with GTCS and 36 age-matched healthy controls. Static and dynamic FC approaches were used to evaluate alterations in the temporal variability of thalamo-cortical networks in children with GTCS. The dynamic effective connectivity (dEC) method was also used to evaluate the directions of the fluctuations in effective connectivity. In addition, the relationships between the dynamic properties and clinical features were assessed. Results The static FC analysis presented significantly decreased connectivity patterns between the bilateral thalamus and between the thalamus and right inferior temporal gyrus. The dynamic connectivity analysis found decreased FC variability in the thalamo-cortical network of children with epilepsy. Dynamic EC analyses identified increased connectivity variability from the frontal gyrus to the bilateral thalamus, and decreased connectivity variability from the right thalamus to the left thalamus and from the right thalamus to the right superior parietal lobe. In addition, correlation analysis revealed that both static FC and connectivity temporal variability in the thalamo-cortical network related to the clinical features (epilepsy duration and epilepsy onset time). Significance Our findings of both increased and decreased connectivity variability in the thalamo-cortical network imply a dynamic restructuring of the functional pathways connecting the thalamus in children with GTCS. These alterations in static and temporal dynamic pathways connecting the bilateral thalamus may extend our understanding of the neural mechanisms underlying the GTCS in children.
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Affiliation(s)
- Yongxin Li
- Guangzhou Key Laboratory of Formula-Pattern of Traditional Chinese Medicine, Formula-pattern Research Center, School of Traditional Chinese Medicine, Jinan University, Guangzhou, China
- *Correspondence: Yongxin Li,
| | - Jianping Wang
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiao Wang
- Epilepsy Center and Department of Neurosurgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Qian Chen
- Department of Pediatric Neurosurgery, Shenzhen Children’s Hospital, Shenzhen, China
| | - Bing Qin
- Epilepsy Center and Department of Neurosurgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Jiaxu Chen
- Guangzhou Key Laboratory of Formula-Pattern of Traditional Chinese Medicine, Formula-pattern Research Center, School of Traditional Chinese Medicine, Jinan University, Guangzhou, China
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Moshir Estekhareh SS, Saghebdoust S, Zare R, Hakak MA, Hashemabadi BAG. Memory and executive functioning outcomes of selective amygdalohippocampectomy in patients with hippocampal sclerosis: A preliminary study in a developing country. Surg Neurol Int 2022; 13:161. [PMID: 35509560 PMCID: PMC9062935 DOI: 10.25259/sni_49_2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 04/05/2022] [Indexed: 11/24/2022] Open
Abstract
Background Selective amygdalohippocampectomy (SA) is an effective treatment for drug-resistant cases of epilepsy due to hippocampal sclerosis (HS). However, its neurocognitive outcomes are inconsistent across the previous studies, pointing to potential location-specific confounders. Here, we investigated the neurocognitive outcomes of SA in an Iranian center recently adopting this approach. Methods Thirty adults (53.3% of females, age 31.4 ± 6.2 years) with drug-resistant epilepsy due to HS were included in the study. Patients were stratified into surgical (n = 15) and medical (n = 15) treatment groups based on their preferences. Neurocognitive function was assessed before and 6 months after intervention using Wisconsin Card Sorting Test (WCST), Wechsler Adult Intelligence Scale-Revised, and Wechsler Memory Scale- Third Edition (WMS-III). Postintervention performance changes were compared between the two groups, and predictors of worse postoperative outcomes were investigated. Results Longitudinal changes of performance in WMS-III and WCST were significantly different between the surgically and medically treated patients. Postoperative WMS-III performance showed an average 25% decline (mean ∆T2-T1 = -25.1%, T = -6.6, P < 0.001), and WCST performance improved by an average of 49% (mean ∆T2-T1 = +49.1%, T = 4.6, P < 0.001). The decline in memory performance was more severe in the left-sided surgery and in patients with higher baseline education (mean ∆T2-T1 = -31.1%, T = -8.9, P < 0.001). Conclusion In our center, executive functioning improved or remained stable after SA, but memory functions declined moderately. The left-sided SA and higher education were associated with more severe decline in memory functions, highlighting the need for special considerations for these groups.
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Affiliation(s)
| | - Sajjad Saghebdoust
- Department of Neurosurgery, Epilepsy Center, Razavi Hospital, Mashhad, Iran
| | - Reza Zare
- Department of Neurosurgery, Epilepsy Center, Razavi Hospital, Mashhad, Iran
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Aberrant cerebral intrinsic activity and cerebro-cerebellar functional connectivity in right temporal lobe epilepsy: a resting-state functional MRI study. Neuroreport 2021; 32:1009-1016. [PMID: 34075003 DOI: 10.1097/wnr.0000000000001681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Numerous neuroimaging studies have demonstrated that functional brain aberrations are associated with cognitive impairments in temporal lobe epilepsy (TLE). Here, we aimed to investigate the neural substrates of attention deficits by combining assessment of regional intrinsic brain activities with large-scale functional connectivity in patients with right TLE (rTLE). METHODS Thirty-five patients with rTLE and 33 matched healthy controls were recruited. All participants completed the Attention Network Test (ANT) and resting-sate functional MRI (rs-fMRI) scans. The z-standardized fractional amplitude of the low-frequency fluctuation (zfALFF) approach was applied to evaluate the brain's intrinsic activity. The cerebral regions with significant zfALFF values were selected as seeds for subsequent functional connectivity analyses. A correlation analysis was performed between functional activity and clinical variables. RESULTS Compared with the healthy control group, the patients showed decreased zfALFF in the right inferior temporal gyrus and bilateral superior parietal gyrus, and the right inferior temporal gyrus exhibited increased functional connectivity with the bilateral cerebellum-6/vermis-6 and decreased functional connectivity with right superior frontal gyrus. The ANT indicated that the rTLE group exhibited attention deficits. Furthermore, a positive correlation was found between the zfALFF value of the left superior parietal gyrus and alerting performance, while a negative correlation between the zfALFF value of the right superior parietal gyrus and disease duration. CONCLUSION This study demonstrated aberrant intrinsic cerebral activity and functional connectivity in the whole brain network, which may act as responsible and compensatory factors in attention deficits, especially further profoundly illuminated the compensatory role of cerebellum in patients with rTLE.
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Li R, Hu C, Wang L, Liu D, Liu D, Liao W, Xiao B, Chen H, Feng L. Disruption of functional connectivity among subcortical arousal system and cortical networks in temporal lobe epilepsy. Brain Imaging Behav 2021; 14:762-771. [PMID: 30617780 DOI: 10.1007/s11682-018-0014-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Growing evidence has demonstrated widespread brain network alterations in temporal lobe epilepsy (TLE). However, the relatively accurate portrait of the subcortical-cortical relationship for impaired consciousness in TLE remains unclear. We proposed that consciousness-impairing seizures may invade subcortical arousal system and corresponding cortical regions, resulting in functional abnormalities and information flow disturbances between subcortical and cortical networks. We performed resting-state fMRI in 26 patients with TLE and 30 matched healthy controls. All included patients were diagnosed with impaired awareness during focal temporal lobe seizures. Functional connectivity density was adopted to determine whether local or distant network alterations occurred in TLE, and Granger causality analysis (GCA) was utilized to assess the direction and magnitude of causal influence among these altered brain networks further. Patients showed increased local functional connectivity in several arousal structures, such as the midbrain, thalamus, and cortical regions including bilateral prefrontal cortex (PFC), left superior temporal pole, left posterior insula, and cerebellum (P < 0.05, FDR corrected). GCA analysis revealed that the casual effects among these regions in patients were significantly sparser than those in controls (P < 0.05, uncorrected), including decreased excitatory and inhibitory effects among the midbrain, thalamus and PFC, and decreased inhibitory effect from the cerebellum to PFC. These findings suggested that consciousness-impairing seizures in TLE are associated with functional alterations and disruption of information process between the subcortical arousal system and cortical network. Understanding the functional networks and innervation pathway involved in TLE can provide insights into the mechanism underlying seizure-related loss of consciousness.
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Affiliation(s)
- Rong Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China
| | - Chongyu Hu
- Department of Neurology, Hunan Provincial People's Hospital, Changsha, 410005, People's Republic of China
| | - Liangcheng Wang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China
| | - Ding Liu
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, 410013, People's Republic of China
| | - Dingyang Liu
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, 410008, People's Republic of China
| | - Wei Liao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, People's Republic of China
| | - Huafu Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
| | - Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, People's Republic of China.
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Shih YC, Lin FH, Liou HH, Tseng WYI. Seizure Frequency Is Associated with Effective Connectivity of the Hippocampal-Diencephalic-Cingulate in Epilepsy with Unilateral Mesial Temporal Sclerosis. Brain Connect 2021; 11:457-470. [PMID: 33403892 DOI: 10.1089/brain.2020.0835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Temporal lobe epilepsy (TLE) with mesial temporal sclerosis (MTS) is a common intractable epilepsy. To seek neural correlates of seizure recurrence, this study investigated aberrant intrinsic effective connectivity (iEC) in TLE with unilateral MTS and their associations with seizure frequency. Methods: Thirty patients with unilateral MTS (left/right MTS = 14/16) and 37 age-matched healthy controls underwent resting-state functional magnetic resonance imaging (rsfMRI) on a 3-Tesla magnetic resonance imaging (MRI) system. The structural equation modeling was employed to estimate the iEC of the three candidate epilepsy models, including the Papez circuit, hippocampal-diencephalic-cingulate (HDC) model, and simplified HDC model. After comparing the performance of model fitting, the best model was selected to compare iEC among the study groups. The linear regression analysis was performed to associate abnormal iEC with seizure frequency. Results: The simplified HDC model was the best model to estimate iEC across the three study groups (p < 0.05), and it composed of the 26 interconnected pathway between the mesial temporal lobe, thalamus, and cingulate cortices. The linear regression analysis revealed a significant relationship between the shared iEC alterations in both patient groups and seizure frequency (adjusted-R2 = 0.350; p = 0.037), including the three paths of mammillary body (MB) → bilateral anterior thalamic nuclei (left: standardized β-value = 0.580, p = 0.013; right: standardized β-value = -0.711, p = 0.006) and right hippocampus → MB (standardized β-value = 0.541, p = 0.045). Conclusions: Our findings provide new insights into neurophysiological significance relevant to seizure recurrence. Aberrant iEC on the neural paths connected to the MB can be a potential imaging marker, aiding the therapeutic management in TLE with unilateral MTS. Impact statement Within the simplified hippocampal-diencephalic-cingulate model, we identified that altered intrinsic effective connectivity (iEC) on the three paths connecting to the mammillary body was common in temporal lobe epilepsy (TLE) with left and right mesial temporal sclerosis (MTS) and was associated with seizure frequency. Therefore, these common iEC alterations could be a potential imaging marker, aiding the therapeutic management in patients with TLE with unilateral MTS.
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Affiliation(s)
- Yao-Chia Shih
- Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.,Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore
| | - Fa-Hsuan Lin
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - Horng-Huei Liou
- Department of Neurology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wen-Yih Isaac Tseng
- Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Medical Imaging, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.,Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
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Li L, He L, Harris N, Zhou Y, Engel J, Bragin A. Topographical reorganization of brain functional connectivity during an early period of epileptogenesis. Epilepsia 2021; 62:1231-1243. [PMID: 33720411 DOI: 10.1111/epi.16863] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The current study aims to investigate functional brain network representations during the early period of epileptogenesis. METHODS Eighteen rats with the intrahippocampal kainate model of mesial temporal lobe epilepsy were used for this experiment. Functional magnetic resonance imaging (fMRI) measurements were made 1 week after status epilepticus, followed by 2-4-month electrophysiological and video monitoring. Animals were identified as having (1) developed epilepsy (E+, n = 9) or (2) not developed epilepsy (E-, n = 6). Nine additional animals served as controls. Graph theory analysis was performed on the fMRI data to quantify the functional brain networks in all animals prior to the development of epilepsy. Spectrum clustering with the network features was performed to estimate their predictability in epileptogenesis. RESULTS Our data indicated that E+ animals showed an overall increase in functional connectivity strength compared to E- and control animals. Global network features and small-worldness of E- rats were similar to controls, whereas E+ rats demonstrated increased small-worldness, including increased reorganization degree, clustering coefficient, and global efficiency, with reduced shortest pathlength. A notable classification of the combined brain network parameters was found in E+ and E- animals. For the local network parameters, the E- rats showed increased hubs in sensorimotor cortex, and decreased hubness in hippocampus. The E+ rats showed a complete loss of hippocampal hubs, and the appearance of new hubs in the prefrontal cortex. We also observed that lesion severity was not related to epileptogenesis. SIGNIFICANCE Our data provide a view of the reorganization of topographical functional brain networks in the early period of epileptogenesis and how it can significantly predict the development of epilepsy. The differences from E- animals offer a potential means for applying noninvasive neuroimaging tools for the early prediction of epilepsy.
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Affiliation(s)
- Lin Li
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA.,Department of Biomedical Engineering, University of North Texas, Denton, Texas, USA
| | - Lingna He
- Department of Computer Science, Zhejiang University of Technology, Zhejiang, China
| | - Neil Harris
- Department of Neurosurgery, UCLA Brain Injury Research Center, University of California, Los Angeles,, Los Angeles, California, USA.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA.,Semel Institute for Neuroscience and Human Behavior, Intellectual Development and Disorders Research Center, University of California, Los Angeles, Los Angeles, California, USA
| | - Yufeng Zhou
- Department of Biomedical Engineering, University of North Texas, Denton, Texas, USA
| | - Jerome Engel
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA.,Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.,Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Anatol Bragin
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA
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People with mesial temporal lobe epilepsy have altered thalamo-occipital brain networks. Epilepsy Behav 2020; 115:107645. [PMID: 33334720 PMCID: PMC7882020 DOI: 10.1016/j.yebeh.2020.107645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/05/2020] [Accepted: 11/16/2020] [Indexed: 02/06/2023]
Abstract
While temporal lobe epilepsy (TLE) is a focal epilepsy, previous work demonstrates that TLE causes widespread brain-network disruptions. Impaired visuospatial attention and learning in TLE may be related to thalamic arousal nuclei connectivity. Our prior preliminary work in a smaller patient cohort suggests that patients with TLE demonstrate abnormal functional connectivity between central lateral (CL) thalamic nucleus and medial occipital lobe. Others have shown pulvinar connectivity disturbances in TLE, but it is incompletely understood how TLE affects pulvinar subnuclei. Also, the effects of epilepsy surgery on thalamic functional connectivity remains poorly understood. In this study, we examine the effects of TLE on functional connectivity of two key thalamic arousal-nuclei: lateral pulvinar (PuL) and CL. We evaluate resting-state functional connectivity of the PuL and CL in 40 patients with TLE and 40 controls using fMRI. In 25 patients, postoperative images (>1 year) were also compared with preoperative images. Compared to controls, patients with TLE exhibit loss of normal positive connectivity between PuL and lateral occipital lobe (p < 0.05), and a loss of normal negative connectivity between CL and medial occipital lobe (p < 0.01, paired t-tests). FMRI amplitude of low-frequency fluctuation (ALFF) in TLE trended higher in ipsilateral PuL (p = 0.06), but was lower in the lateral occipital (p < 0.01) and medial occipital lobe in patients versus controls (p < 0.05, paired t-tests). More abnormal ALFF in the ipsilateral lateral occipital lobe is associated with worse preoperative performance on Rey Complex Figure Test Immediate (p < 0.05, r = 0.381) and Delayed scores (p < 0.05, r = 0.413, Pearson's Correlations). After surgery, connectivity between PuL and lateral occipital lobe remains abnormal in patients (p < 0.01), but connectivity between CL and medial occipital lobe improves and is no longer different from control values (p > 0.05, ANOVA, post hoc Fischer's LSD). In conclusion, thalamic arousal nuclei exhibit abnormal connectivity with occipital lobe in TLE, and some connections may improve after surgery. Studying thalamic arousal centers may help explain distal network disturbances in TLE.
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Singh TB, Aisikaer A, He C, Wu Y, Chen H, Ni H, Song Y, Yin J. The Assessment of Brain Functional Changes in the Temporal Lobe Epilepsy Patient with Cognitive Impairment by Resting-state Functional Magnetic Resonance Imaging. J Clin Imaging Sci 2020; 10:50. [PMID: 32874755 PMCID: PMC7451150 DOI: 10.25259/jcis_55_2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/30/2020] [Indexed: 12/11/2022] Open
Abstract
Objectives The objective of the study was to detect functional changes in the brain of cognitive impairment-temporal lobe epilepsy (CI-TLE) patient and to sort out the possible mechanism involved in CI in CI-TLE patients using resting-state functional magnetic resonance imaging (RS-fMRI). Material and Methods Fifty-eight TLE cases were included, which was divided into 44 TLE patients without CI (cognitive not impairment [CNI]-TLE) and 14 TLE patients with CI (CI-TLE). The normal control (NC) group consisted of 40 participants. RS-fMRI data preprocessing was carried out in statistical parametric mapping (SPM) software. The data were realigned, coregistered, normalized, and finally smoothened and then were taken for amplitude of low-frequency fluctuation (ALFF) calculation in RS-fMRI data analysis toolkit (REST) software. For data analysis, voxel-wise two-sample t-test was carried out between TLE group and NC group; CI-TLE group and cognitive not impairment-TLE (CNI-TLE) group in SPM software, a cluster >10 voxels and P < 0.01 was considered to be significant. Results Compared to NC, the TLE patients showed increased ALFF activation mostly in parahippocampal gyrus (PG), frontal lobe, midbrain, pons, insula, inferior temporal gyrus, and anterior cingulate gyrus (ACG) while decreased ALFF value was seen in posterior cingulate gyrus, cuneus, cerebellum posterior lobe, inferior parietal lobule (IPL), and superior temporal gyrus. Compared to CNI-TLE, CI-TLE patients showed increased ALFF in middle temporal gyrus (MTG), cuneus, ACG, IPL, middle frontal gyrus (MFG), superior frontal gyrus (SFG), cerebellum posterior lobe, and decreased ALFF cluster in the corpus callosum and MFG. Conclusion Between TLE and NC, we found increased ALFF activation in PG, frontal lobe, thalamus, insula, midbrain, and pons in TLE patient. Between CI and CNI TLE, area of executive control network and default model network, especially in MTG, ACG, IPL, MFG, and SFG, had increased ALFF value in CI-TLE patient. Activation of these areas should be because of the decompensation mechanism.
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Affiliation(s)
| | - Aikedan Aisikaer
- Department of Radiology, Tianjin First Central Hospital, Nankai, China
| | - Che He
- Department of Radiology, Tianjin First Central Hospital, Nankai, China
| | - Yalin Wu
- Department of Radiology, Tianjin First Central Hospital, Nankai, China
| | - Hong Chen
- Department of Radiology, Tianjin First Central Hospital, Nankai, China
| | - Hongyan Ni
- Department of Radiology, Tianjin First Central Hospital, Nankai, China
| | - Yijun Song
- Department of Radiology, Tianjin Medical University General Hospital, Heping, Tianjin
| | - Jianzhong Yin
- Department of Radiology, Tianjin First Central Hospital, Nankai, China
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11
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Zhou B, An D, Xiao F, Niu R, Li W, Li W, Tong X, Kemp GJ, Zhou D, Gong Q, Lei D. Machine learning for detecting mesial temporal lobe epilepsy by structural and functional neuroimaging. Front Med 2020; 14:630-641. [PMID: 31912429 DOI: 10.1007/s11684-019-0718-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/07/2019] [Indexed: 02/04/2023]
Abstract
Mesial temporal lobe epilepsy (mTLE), the most common type of focal epilepsy, is associated with functional and structural brain alterations. Machine learning (ML) techniques have been successfully used in discriminating mTLE from healthy controls. However, either functional or structural neuroimaging data are mostly used separately as input, and the opportunity to combine both has not been exploited yet. We conducted a multimodal ML study based on functional and structural neuroimaging measures. We enrolled 37 patients with left mTLE, 37 patients with right mTLE, and 74 healthy controls and trained a support vector ML model to distinguish them by using each measure and the combinations of the measures. For each single measure, we obtained a mean accuracy of 74% and 69% for discriminating left mTLE and right mTLE from controls, respectively, and 64% when all patients were combined. We achieved an accuracy of 78% by integrating functional data and 79% by integrating structural data for left mTLE, and the highest accuracy of 84% was obtained when all functional and structural measures were combined. These findings suggest that combining multimodal measures within a single model is a promising direction for improving the classification of individual patients with mTLE.
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Affiliation(s)
- Baiwan Zhou
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Dongmei An
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Fenglai Xiao
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, 610041, China.,Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, WC1E 6BT, UK
| | - Running Niu
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Wenbin Li
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Wei Li
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Xin Tong
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Graham J Kemp
- Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, L9 7AL, UK
| | - Dong Zhou
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, 610041, China.
| | - Qiyong Gong
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, China.,Department of Psychology, School of Public Administration, Sichuan University, Chengdu, 610041, China
| | - Du Lei
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, 610041, China. .,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 8AF, UK. .,Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, 45219, USA.
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12
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Gil F, Padilla N, Soria-Pastor S, Setoain X, Boget T, Rumiá J, Roldán P, Reyes D, Bargalló N, Conde E, Pintor L, Vernet O, Manzanares I, Ådén U, Carreño M, Donaire A. Beyond the Epileptic Focus: Functional Epileptic Networks in Focal Epilepsy. Cereb Cortex 2019; 30:2338-2357. [DOI: 10.1093/cercor/bhz243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Abstract
Focal epilepsy can be conceptualized as a network disorder, and the functional epileptic network can be described as a complex system of multiple brain areas that interact dynamically to generate epileptic activity. However, we still do not fully understand the functional architecture of epileptic networks. We studied a cohort of 21 patients with extratemporal focal epilepsy. We used independent component analysis of functional magnetic resonance imaging (fMRI) data. In order to identify the epilepsy-related components, we examined the general linear model-derived electroencephalography-fMRI (EEG–fMRI) time courses associated with interictal epileptic activity as intrinsic hemodynamic epileptic biomarkers. Independent component analysis revealed components related to the epileptic time courses in all 21 patients. Each epilepsy-related component described a network of spatially distributed brain areas that corresponded to the specific epileptic network in each patient. We also provided evidence for the interaction between the epileptic activity generated at the epileptic network and the physiological resting state networks. Our findings suggest that independent component analysis, guided by EEG–fMRI epileptic time courses, have the potential to define the functional architecture of the epileptic network in a noninvasive way. These data could be useful in planning invasive EEG electrode placement, guiding surgical resections, and more effective therapeutic interventions.
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Affiliation(s)
- Francisco Gil
- Epilepsy Program, Department of Neurology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - Nelly Padilla
- Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | - Sara Soria-Pastor
- Department of Psychiatry, Consorci Sanitari del Maresme, Hospital of Mataro, CP 08304, Mataro, Spain
| | - Xavier Setoain
- Epilepsy Program, Department of Nuclear Medicine, Hospital Clínic, CDIC, CP 08036, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Clinical and Experimental Neuroscience, Clinical Neurophysiology, CP 08036, Barcelona, Spain
- Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), University of Barcelona, CP 08036, Barcelona, Spain
| | - Teresa Boget
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Clinical and Experimental Neuroscience, Clinical Neurophysiology, CP 08036, Barcelona, Spain
- Epilepsy Program, Department of Neuropsychology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - Jordi Rumiá
- Epilepsy Program, Department of Neurosurgery, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - Pedro Roldán
- Epilepsy Program, Department of Neurosurgery, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - David Reyes
- Epilepsy Program, Department of Neurology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - Núria Bargalló
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Clinical and Experimental Neuroscience, Clinical Neurophysiology, CP 08036, Barcelona, Spain
- Epilepsy Program, Department of Radiology, Hospital Clínic, CDIC, CP 08036, Barcelona, Spain
| | - Estefanía Conde
- Epilepsy Program, Department of Neurology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - Luis Pintor
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Clinical and Experimental Neuroscience, Clinical Neurophysiology, CP 08036, Barcelona, Spain
- Epilepsy Program, Department of Psychiatry, Hospital Clínic, CDIC, CP 08036, Barcelona, Spain
| | - Oriol Vernet
- Epilepsy Program, Department of Neurology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - Isabel Manzanares
- Epilepsy Program, Department of Neurology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
| | - Ulrika Ådén
- Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | - Mar Carreño
- Epilepsy Program, Department of Neurology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Clinical and Experimental Neuroscience, Clinical Neurophysiology, CP 08036, Barcelona, Spain
| | - Antonio Donaire
- Epilepsy Program, Department of Neurology, Hospital Clínic, Neuroscience Institute, CP 08036, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Clinical and Experimental Neuroscience, Clinical Neurophysiology, CP 08036, Barcelona, Spain
- Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), University of Barcelona, CP 08036, Barcelona, Spain
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13
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Chang J, Yu R. Hippocampal connectivity in the aftermath of acute social stress. Neurobiol Stress 2019; 11:100195. [PMID: 31832509 PMCID: PMC6889252 DOI: 10.1016/j.ynstr.2019.100195] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/06/2019] [Accepted: 09/13/2019] [Indexed: 12/12/2022] Open
Abstract
The hippocampus is a core brain region that responds to stress. Previous studies have found a dysconnectivity between hippocampus and other brain regions under acute and chronic stress. However, whether and how acute social stress influences the directed connectivity patterns from and to the hippocampus remains unclear. In this study, using a within-subject design and Granger causal analysis (GCA), we investigated the alterations of resting state effective connectivity from and to hippocampal subregions after an acute social stressor (the Trier Social Stress Test). Participants were engaged in stress and control conditions spaced approximately one month apart. Our findings showed that stress altered the information flows in the thalamus-hippocampus-insula/midbrain circuit. The changes in this circuit could also predict with high accuracy the stress and control conditions at the subject level. These hippocampus-related brain networks have been documented to be involved in emotional information processing and storage, as well as habitual responses. We speculate that alterations of the effective connectivity between these brain regions may be associated with the registering and encoding of threatening stimuli under stress. Our investigation of hippocampal functional connectivity at a subregional level may help elucidate the functional neurobiology of stress-related psychiatric disorders.
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Affiliation(s)
- Jingjing Chang
- Guangdong Key Laboratory of Mental Health and Cognitive Science, Center for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China
| | - Rongjun Yu
- Department of Psychology, National University of Singapore, Singapore
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14
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Liao W, Fan YS, Yang S, Li J, Duan X, Cui Q, Chen H. Preservation Effect: Cigarette Smoking Acts on the Dynamic of Influences Among Unifying Neuropsychiatric Triple Networks in Schizophrenia. Schizophr Bull 2019; 45:1242-1250. [PMID: 30561724 PMCID: PMC6811814 DOI: 10.1093/schbul/sby184] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The high prevalence of cigarette smoking in schizophrenia (SZ) is generally explained by the self-medication theory. However, its neurobiological mechanism remains unclear. The impaired dynamic of influences among unifying neuropsychiatric triple networks in SZ, including the central executive network (CEN), the default mode network (DMN), and the salience network (SN), might explain the nature of their syndromes, whereas smoking could regulate the dynamics within networks. Therefore, this study examined whether cigarette smoking could elicit a distinct improvement in the dynamics of triple networks in SZ and associated with the alleviation of symptoms. METHODS Four groups were recruited, namely, SZ smoking (n = 22)/nonsmoking (n = 25), and healthy controls smoking (n = 22)/nonsmoking (n = 21). All participants underwent a resting-state functional magnetic resonance imaging (fMRI). The dynamics among unifying neuropsychiatric triple networks were measured using Granger causality analysis on the resting-sate fMRI signal. Interaction effects between SZ and smoking on dynamics were detected using 2-way analysis of covariance, correcting for sex, age, and education level. RESULTS Whereas smoking reduced SN→DMN dynamic in healthy controls, it preserved the dynamic in SZ, thus suggesting a preservation effect. Moreover, smoking additionally increased DMN→CEN dynamic in SZ. CONCLUSIONS This finding from neural pathways shed new insights into the prevailing self-medication hypothesis in SZ. More broadly, this study elaborates on the neurobiological dynamics that may assist in the treatment of the symptomatology of SZ.
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Affiliation(s)
- Wei Liao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, P.R. China
- School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu, P.R. China
| | - Yun-Shuang Fan
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, P.R. China
- School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu, P.R. China
| | - Siqi Yang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, P.R. China
- School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu, P.R. China
| | - Jiao Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, P.R. China
- School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu, P.R. China
| | - Xujun Duan
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, P.R. China
- School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu, P.R. China
| | - Qian Cui
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, P.R. China
- School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu, P.R. China
| | - Huafu Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, P.R. China
- School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu, P.R. China
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15
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Liu H, Li W, Zhao M, Wu J, Wu J, Yang J, Jiao B. Altered temporal dynamics of brain activity in patients with generalized tonic-clonic seizures. PLoS One 2019; 14:e0219904. [PMID: 31314786 PMCID: PMC6636756 DOI: 10.1371/journal.pone.0219904] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 07/04/2019] [Indexed: 12/31/2022] Open
Abstract
Generalized seizures engage bilateral networks from their onset at a low temporal scale. Previous studies findings have demonstrated focal/local brain activity abnormalities in the patients with generalized tonic-clonic seizures (GTCS). Resting state functional magnetic resonance imaging (fMRI) allows the detection of aberrant spontaneous brain activity in GTCS. Little is known, however, about alterations of dynamics (temporal variability) of spontaneous brain activity. It also remains unclear whether temporal variability of spontaneous brain activity is associated with disease severity. To address these questions, the current study assessed patients with GTCS (n = 35), and age- and sex-matched healthy controls (HCs, n = 33) who underwent resting state fMRI. We first assessed the dynamics of spontaneous brain activity using dynamic amplitude of low-frequency fluctuation (dALFF). Furthermore, the temporal variability of brain activity was quantified as the variance of dALFF across sliding window. Compared to HCs, patients with GTCS showed hyper-temporal variability of dALFF in parts of the default mode network, whereas they showed hypo-temporal variability in the somatomotor cortex. Furthermore, dynamic ALFF in the subgenual anterior cingulate cortex was positively correlated with duration of disease, indicating that disease severity is associated with excessive variability. These results suggest both an excessive variability and excessive stability in patients with GTCS. Overall, the current findings from brain activity dynamics contribute to our understanding of the pathophysiological mechanisms of generalized seizure.
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Affiliation(s)
- Honglei Liu
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, P.R. China
- Department of Neurosurgery, Shijiazhuang the Third Hospital, Shijiazhuang, P.R. China
| | - Wenling Li
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, P.R. China
| | - Mingjuan Zhao
- Medical Imaging Department, Hebei General Hospital, Shijiazhuang, P.R. China
| | - Jie Wu
- Department of Neurosurgery, Shijiazhuang the Third Hospital, Shijiazhuang, P.R. China
| | - Jing Wu
- Department of Neurosurgery, Shijiazhuang the Third Hospital, Shijiazhuang, P.R. China
| | - Jiankai Yang
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, P.R. China
| | - Baohua Jiao
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, P.R. China
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16
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Klugah-Brown B, Luo C, Peng R, He H, Li J, Dong L, Yao D. Altered structural and causal connectivity in frontal lobe epilepsy. BMC Neurol 2019; 19:70. [PMID: 31023252 PMCID: PMC6485093 DOI: 10.1186/s12883-019-1300-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/11/2019] [Indexed: 01/09/2023] Open
Abstract
Background Albeit the few resting-state fMRI neuroimaging studies in frontal lobe epilepsy (FLE) patients, these studies focused on functional connectivity. The aim of this current study was to examine the effective connectivity based on voxel-based morphometry in FLE patients. Methods Resting-state structural and functional magnetic resonance imaging (fMRI) data were acquired from 19 FLE patients and 19 age and gender-matched healthy controls using the 3.0 Tesla magnetic resonance imaging (3.0 T MRI). The investigations were done by acquiring the structural information through voxel-based morphometry, then based on the seed obtained, Granger causality analysis was used to evaluate the causal flow of the designated seed to and from other significant voxels. Results Our results showed altered structural and effective connectivity. Compared with healthy controls, FLE patients showed reduced grey matter volume in bilateral putamen and right caudate as well as altered causality with increased, and decreased causal outflow from the right caudate (seed region) to inferior frontal gyrus-triangular, from bilateral putamen (seed regions) to right middle frontal gyrus and frontal gyrus medial-orbital representing the frontal executive areas, respectively. Also, significantly increased and decreased inflow from left calcarine to right caudate and from cerebellum_6 and vermis_6 to bilateral putamen, respectively. Moreover, we found that the causal alterations to and from the seed regions (from vermis_6 to right putamen and from left putamen to right middle frontal gyrus) negatively correlated with clinical scores (duration of epilepsy). Conclusions The findings point to the impairment within the executive and motor-controlled system including the cerebellum, frontal, caudate and putamen regions in FLE patients. These results would therefore enhance our understanding of structural and effective mechanisms in FLE.
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Affiliation(s)
- Benjamin Klugah-Brown
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, People's Republic of China
| | - Cheng Luo
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, People's Republic of China.
| | - Rui Peng
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, People's Republic of China
| | - Hui He
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, People's Republic of China
| | - Jianfu Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, People's Republic of China
| | - Li Dong
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, People's Republic of China
| | - Dezhong Yao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu, People's Republic of China
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17
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Zhang C, Zhang H, Xu K, Yang H, Liu C, Yu T, Chen N, Li K. Impaired prefrontal cortex-thalamus pathway in intractable temporal lobe epilepsy with aberrant executive control function: MRI evidence. Clin Neurophysiol 2019; 130:484-490. [DOI: 10.1016/j.clinph.2018.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 11/19/2018] [Accepted: 12/16/2018] [Indexed: 01/03/2023]
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18
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Ashmaig O, Connolly M, Gross RE, Mahmoudi B. Bayesian Optimization of Asynchronous Distributed Microelectrode Theta Stimulation and Spatial Memory. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:2683-2686. [PMID: 30440959 DOI: 10.1109/embc.2018.8512801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
There is a great need for an electrical stimulation therapy to treat medication-resistant, surgically ineligible epileptic patients that successfully reduces seizure incidence with minimal side effects. Critical to advancing such therapies will be identifying the trade-offs between therapeutic efficacy and side effects. One novel treatment developed in the tetanus toxin rat model of mesial temporal lobe epilepsy, asynchronous distributed microelectrode stimulation (ADMETS) in the hippocampus has been shown to significantly reduce seizure frequency. However, our results have demonstrated that ADMETS has a negative effect on spatial memory that scales with the amplitude of stimulation. Given the high dimensional space of possible stimulation parameters, it is difficult to construct a mapping from variations in stimulation to behavioral effect. In this project, we present a novel, principled approach using closed-loop Bayesian optimization to tune stimulation that successfully maximize a desired objective - performance on a spatial memory assay.
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19
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Cui Y, Yu S, Zhang T, Zhang Y, Xia Y, Yao D, Guo D. Altered activity and information flow in the default mode network of pilocarpine-induced epilepsy rats. Brain Res 2018; 1696:71-80. [DOI: 10.1016/j.brainres.2018.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 05/08/2018] [Accepted: 05/13/2018] [Indexed: 01/08/2023]
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20
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Chen S, Fang J, An D, Xiao F, Chen D, Chen T, Zhou D, Liu L. The focal alteration and causal connectivity in children with new-onset benign epilepsy with centrotemporal spikes. Sci Rep 2018; 8:5689. [PMID: 29632387 PMCID: PMC5890242 DOI: 10.1038/s41598-018-23336-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 03/09/2018] [Indexed: 02/05/2023] Open
Abstract
The aim of the current study was to find the epileptic focus and examine its causal relationship to other brain regions in children with new-onset benign childhood epilepsy with centrotemporal spikes (BECTS). Resting-state functional magnetic resonance imaging (fMRI) was performed in 66 children with BECTS and 37 matched control children. We compared the amplitude of low frequency fluctuation (ALFF) signals between the two groups to find the potential epileptogenic zone (EZ), then used Granger causality analysis (GCA) to explore the causal effects of EZ on the whole brain. Children with BECTS had significantly increased ALFF in the right Broca’s area, and decreased ALFF in bilateral fusiform gyrus. The patients also showed increased driving effect from the EZ in Broca’s area to the right prefrontal lobe, and decreased effects to the frontal lobe and posterior parts of the language network. The causal effect on left Wernicke’s area negatively correlated with verbal IQ (VIQ) score. Our research on new-onset BECTS patients illustrates a possible compensatory mechanism in the language network at early stages of BECTS, and the negative correlation of GCA and VIQ suggest the disturbance of epileptiform activity on language. These findings shed light on the mechanisms of and language dysfunction in BECTS.
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Affiliation(s)
- Sihan Chen
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, PR China
| | - Jiajia Fang
- Department of Neurology, Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, PR China
| | - Dongmei An
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, PR China
| | - Fenglai Xiao
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, PR China
| | - Deng Chen
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, PR China
| | - Tao Chen
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, PR China
| | - Dong Zhou
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, PR China.
| | - Ling Liu
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, PR China.
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21
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Kirov II, Kuzniecky R, Hetherington HP, Soher BJ, Davitz MS, Babb JS, Pardoe HR, Pan JW, Gonen O. Whole brain neuronal abnormalities in focal epilepsy quantified with proton MR spectroscopy. Epilepsy Res 2018; 139:85-91. [PMID: 29212047 PMCID: PMC6411059 DOI: 10.1016/j.eplepsyres.2017.11.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/20/2017] [Accepted: 11/28/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To test the hypothesis that localization-related epilepsy is associated with widespread neuronal dysfunction beyond the ictal focus, reflected by a decrease in patients' global concentration of their proton MR spectroscopy (1H-MRS) observed marker, N-acetyl-aspartate (NAA). METHODS Thirteen patients with localization-related epilepsy (7 men, 6 women) 40±13 (mean±standard-deviation)years old, 8.3±13.4years of disease duration; and 14 matched controls, were scanned at 3 T with MRI and whole-brain (WB) 1H MRS. Intracranial fractions of brain volume, gray and white matter (fBV, fGM, fWM) were segmented from the MRI, and global absolute NAA creatine (Cr) and choline (Cho) concentrations were estimated from their WB 1H MRS. These metrics were compared between patients and controls using an unequal variance t test. RESULTS Patients' fBV, fGM and fWM: 0.81±0.07, 0.47±0.04, 0.31±0.04 were not different from controls' 0.79±0.05, 0.48±0.04, 0.32±0.02; nor were their Cr and Cho concentrations: 7.1±1.1 and 1.3±0.2 millimolar (mM) versus 7.7±0.7 and 1.4±0.1mM (p>0.05 all). Patients' global NAA concentration: 11.5±1.5 mM, however, was 12% lower than controls' 13.0±0.8mM (p=0.004). CONCLUSIONS These findings indicate that neuronal dysfunction in localization-related epilepsy extends globally, beyond the ictal zone, but without atrophy or spectroscopic evidence of other pathology. This suggests a diffuse decline in the neurons' health, rather than their number, early in the disease course. WB 1H-MRS assessment, therefore, may be a useful tool for quantification of global neuronal dysfunction load in epilepsy.
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Affiliation(s)
- Ivan I Kirov
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, USA.
| | - Ruben Kuzniecky
- Comprehensive Epilepsy Center, New York University School of Medicine,New York City, NY, USA.
| | - Hoby P Hetherington
- Department of Radiology and Neurology, University of Pittsburgh School of Medicine,Pittsburgh, PA, USA.
| | - Brian J Soher
- Department of Radiology, Duke University Medical Center, Durham NC, USA.
| | - Matthew S Davitz
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, USA.
| | - James S Babb
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, USA.
| | - Heath R Pardoe
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, USA.
| | - Jullie W Pan
- Department of Radiology and Neurology, University of Pittsburgh School of Medicine,Pittsburgh, PA, USA.
| | - Oded Gonen
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, USA.
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22
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Moguilner S, García AM, Mikulan E, Del Carmen García M, Vaucheret E, Amarillo Y, Bekinschtein TA, Ibáñez A. An unaware agenda: interictal consciousness impairments in epileptic patients. Neurosci Conscious 2017; 2017:niw024. [PMID: 30042834 PMCID: PMC6007167 DOI: 10.1093/nc/niw024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/16/2016] [Accepted: 12/21/2016] [Indexed: 01/07/2023] Open
Abstract
Consciousness impairments have been described as a cornerstone of epilepsy. Generalized seizures are usually characterized by a complete loss of consciousness, whereas focal seizures have more variable degrees of responsiveness. In addition to these impairments that occur during ictal episodes, alterations of consciousness have also been repeatedly observed between seizures (i.e. during interictal periods). In this opinion article, we review evidence supporting the novel hypothesis that epilepsy produces consciousness impairments which remain present interictally. Then, we discuss therapies aimed to reduce seizure frequency, which may modulate consciousness between epileptic seizures. We conclude with a consideration of relevant pathophysiological mechanisms. In particular, the thalamocortical network seems to be involved in both seizure generation and interictal consciousness impairments, which could inaugurate a promising translational agenda for epilepsy studies.
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Affiliation(s)
- Sebastian Moguilner
- Laboratory of Experimental Psychology and Neuroscience (LPEN), Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, Buenos Aires, Argentina.,Fundación Escuela de Medicina Nuclear (FUESMEN) and Comisión Nacional de Energía Atómica (CNEA), Buenos Aires, Argentina.,Instituto Balseiro and Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (UNCuyo), Mendoza, Argentina
| | - Adolfo M García
- Laboratory of Experimental Psychology and Neuroscience (LPEN), Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, Buenos Aires, Argentina.,National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina.,Faculty of Elementary and Special Education (FEEyE), National University of Cuyo (UNCuyo), Mendoza, Argentina
| | - Ezequiel Mikulan
- Laboratory of Experimental Psychology and Neuroscience (LPEN), Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, Buenos Aires, Argentina.,National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
| | - Maria Del Carmen García
- Programa de Cirugía de Epilepsia, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - Esteban Vaucheret
- Servicio de Neurologia Infantil del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - Yimy Amarillo
- Consejo Nacional de Investigaciones Científicas y Técnicas, Física Estadística e Interdisciplinaria, Centro Atómico Bariloche, San Carlos de Bariloche, Rio Negro, Argentina
| | | | - Agustín Ibáñez
- Laboratory of Experimental Psychology and Neuroscience (LPEN), Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, Buenos Aires, Argentina.,National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina.,Universidad Autónoma del Caribe, Barranquilla, Colombia.,Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibáñez, Santiago de Chile, Chile.,Australian Research Council Centre of Excellence in Cognition and its Disorders, Sydney, Australia
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23
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Yang H, Wang C, Zhang Y, Xia L, Feng Z, Li D, Xu S, Xie H, Chen F, Shi Y, Wang J. Disrupted Causal Connectivity Anchored in the Posterior Cingulate Cortex in Amnestic Mild Cognitive Impairment. Front Neurol 2017; 8:10. [PMID: 28167926 PMCID: PMC5256067 DOI: 10.3389/fneur.2017.00010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 01/09/2017] [Indexed: 12/13/2022] Open
Abstract
Amnestic mild cognitive impairment (aMCI) is a transitional stage between normal cognitive aging and Alzheimer’s disease. Previous studies have found that neuronal activity and functional connectivity impaired in many functional networks, especially in the default mode network (DMN), which is related to significantly impaired cognitive and memory functions in aMCI patients. However, few studies have focused on the effective connectivity of the DMN and its subsystems in aMCI patients. The posterior cingulate cortex (PCC) is considered a crucial region in connectivity of the DMN and its key subsystem. In this study, using the coefficient Granger causality analysis approach and using the PCC as the region of interest, we explored changes in the DMN and its subsystems in effective connectivity with other brain regions as well as in correlations among them in 16 aMCI patients and 15 age-matched cognitively normal elderly. Results showed decreased effective connectivity from PCC to whole brain in the left prefrontal cortex, the left medial temporal lobe (MTL), the left fusiform gyrus (FG), and the left cerebellar hemisphere, meanwhile, right temporal lobe showed increased effective connectivity from PCC to the whole brain in aMCI patients compared with normal control. In addition, compared with the normal controls, increased effective connectivity of the whole brain to the PCC in aMCI patients was found in the right thalamus, left medial temporal lobe, left FG, and left cerebellar hemisphere. Compared with the normal controls, no reduced effective connectivity was found in any brain regions from the whole brain to the PCC in aMCI patients. The reduced effective connectivity of the PCC to left MTL showed negative correlation trend with neuropsychological tests (Auditory Verbal Learning Test-immediate recall and clock drawing test) in aMCI patients. Our study shows that aMCI patients have abnormalities in effective connectivity within the PCC-centered DMN network and its posterior subsystems as well as in the cerebellar hemisphere and thalamus. Abnormal integration of networks may be related to cognitive and memory impairment and compensation mechanisms in aMCI patients.
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Affiliation(s)
- Hong Yang
- Department of Radiology, The First Affiliated Hospital of College of Medicine, Zhejiang University , Hangzhou , China
| | - Chengwei Wang
- Department of CT/MRI, The First Affiliated Hospital of the Medical College, Shihezi University, Shihezi, China; Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yumei Zhang
- Department of Radiology, The First Affiliated Hospital of College of Medicine, Zhejiang University, Hangzhou, China; Department of CT/MRI, The First Affiliated Hospital of the Medical College, Shihezi University, Shihezi, China
| | - Liming Xia
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, Hubei , China
| | - Zhan Feng
- Department of Radiology, The First Affiliated Hospital of College of Medicine, Zhejiang University , Hangzhou , China
| | - Deqiang Li
- Department of Neurology, The First Affiliated Hospital of College of Medicine, Zhejiang University , Hangzhou , China
| | - Shunliang Xu
- Department of Radiology, The First Affiliated Hospital of College of Medicine, Zhejiang University , Hangzhou , China
| | - Haiyan Xie
- Department of Psychiatry, The Fourth Affiliated Hospital Zhejiang University School of Medicine , Yiwu , China
| | - Feng Chen
- Department of Radiology, The First Affiliated Hospital of College of Medicine, Zhejiang University , Hangzhou , China
| | - Yushu Shi
- Department of Radiology, The First Affiliated Hospital of College of Medicine, Zhejiang University , Hangzhou , China
| | - Jue Wang
- Center for Cognition and Brain Disorders, Affiliated Hospital, Hangzhou Normal University , Hangzhou , China
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24
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Chiang S, Guindani M, Yeh HJ, Haneef Z, Stern JM, Vannucci M. Bayesian vector autoregressive model for multi-subject effective connectivity inference using multi-modal neuroimaging data. Hum Brain Mapp 2016; 38:1311-1332. [PMID: 27862625 DOI: 10.1002/hbm.23456] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 10/13/2016] [Accepted: 10/25/2016] [Indexed: 11/05/2022] Open
Abstract
In this article a multi-subject vector autoregressive (VAR) modeling approach was proposed for inference on effective connectivity based on resting-state functional MRI data. Their framework uses a Bayesian variable selection approach to allow for simultaneous inference on effective connectivity at both the subject- and group-level. Furthermore, it accounts for multi-modal data by integrating structural imaging information into the prior model, encouraging effective connectivity between structurally connected regions. They demonstrated through simulation studies that their approach resulted in improved inference on effective connectivity at both the subject- and group-level, compared with currently used methods. It was concluded by illustrating the method on temporal lobe epilepsy data, where resting-state functional MRI and structural MRI were used. Hum Brain Mapp 38:1311-1332, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Sharon Chiang
- Department of Statistics, Rice University, Houston, Texas
| | - Michele Guindani
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Hsiang J Yeh
- Department of Neurology, University of California Los Angeles, Los Angeles, California
| | - Zulfi Haneef
- Department of Neurology, Baylor College of Medicine, Houston, Texas
| | - John M Stern
- Department of Neurology, University of California Los Angeles, Los Angeles, California
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25
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Zhao Z, Wang X, Fan M, Yin D, Sun L, Jia J, Tang C, Zheng X, Jiang Y, Wu J, Gong J. Altered Effective Connectivity of the Primary Motor Cortex in Stroke: A Resting-State fMRI Study with Granger Causality Analysis. PLoS One 2016; 11:e0166210. [PMID: 27846290 PMCID: PMC5112988 DOI: 10.1371/journal.pone.0166210] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 10/25/2016] [Indexed: 12/16/2022] Open
Abstract
The primary motor cortex (M1) is often abnormally recruited in stroke patients with motor disabilities. However, little is known about the alterations in the causal connectivity of M1 following stroke. The purpose of the present study was to investigate whether the effective connectivity of the ipsilesional M1 is disturbed in stroke patients who show different outcomes in hand motor function. 23 patients with left-hemisphere subcortical stroke were selected and divided into two subgroups: partially paralyzed hands (PPH) and completely paralyzed hands (CPH). Further, 24 matched healthy controls (HCs) were recruited. A voxel-wise Granger causality analysis (GCA) on the resting-state fMRI data between the ipsilesional M1 and the whole brain was performed to explore differences between the three groups. Our results showed that the influence from the frontoparietal cortices to ipsilesional M1 was diminished in both stroke subgroups and the influence from ipsilesional M1 to the sensorimotor cortices decreased greater in the CPH group than in the PPH group. Moreover, compared with the PPH group, the decreased influence from ipsilesional M1 to the contralesional cerebellum and from the contralesional superior parietal lobe to ipsilesional M1 were observed in the CPH group, and their GCA values were positively correlated with the FMA scores; Conversely, the increased influence from ipsilesional M1 to the ipsilesional middle frontal gyrus and middle temporal gyrus were observed, whose GCA values were negatively correlated with the FMA scores. This study suggests that the abnormalities of casual flow in the ipsilesional M1 are related to the severity of stroke-hand dysfunction, providing valuable information to understand the deficits in resting-state effective connectivity of motor execution and the frontoparietal motor control network during brain plasticity following stroke.
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Affiliation(s)
- Zhiyong Zhao
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200062, China
| | - Xiangmin Wang
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200062, China
| | - Mingxia Fan
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200062, China
- * E-mail: (MF); (JJ)
| | - Dazhi Yin
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Limin Sun
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Jie Jia
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China
- * E-mail: (MF); (JJ)
| | - Chaozheng Tang
- Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Xiaohui Zheng
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200062, China
| | - Yuwei Jiang
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200062, China
| | - Jie Wu
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200062, China
| | - Jiayu Gong
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, 200062, China
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26
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Zhang J, Li C, Jiang T. New Insights into Signed Path Coefficient Granger Causality Analysis. Front Neuroinform 2016; 10:47. [PMID: 27833547 PMCID: PMC5082311 DOI: 10.3389/fninf.2016.00047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 10/13/2016] [Indexed: 11/13/2022] Open
Abstract
Granger causality analysis, as a time series analysis technique derived from econometrics, has been applied in an ever-increasing number of publications in the field of neuroscience, including fMRI, EEG/MEG, and fNIRS. The present study mainly focuses on the validity of “signed path coefficient Granger causality,” a Granger-causality-derived analysis method that has been adopted by many fMRI researches in the last few years. This method generally estimates the causality effect among the time series by an order-1 autoregression, and defines a positive or negative coefficient as an “excitatory” or “inhibitory” influence. In the current work we conducted a series of computations from resting-state fMRI data and simulation experiments to illustrate the signed path coefficient method was flawed and untenable, due to the fact that the autoregressive coefficients were not always consistent with the real causal relationships and this would inevitablely lead to erroneous conclusions. Overall our findings suggested that the applicability of this kind of causality analysis was rather limited, hence researchers should be more cautious in applying the signed path coefficient Granger causality to fMRI data to avoid misinterpretation.
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Affiliation(s)
- Jian Zhang
- School of Mathematical Sciences, Zhejiang UniversityHangzhou, China; Brainnetome Center, Institute of Automation, Chinese Academy of SciencesBeijing, China
| | - Chong Li
- School of Mathematical Sciences, Zhejiang University Hangzhou, China
| | - Tianzi Jiang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences Beijing, China
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27
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Zhang Z, Liao W, Xu Q, Wei W, Zhou HJ, Sun K, Yang F, Mantini D, Ji X, Lu G. Hippocampus-associated causal network of structural covariance measuring structural damage progression in temporal lobe epilepsy. Hum Brain Mapp 2016; 38:753-766. [PMID: 27677885 DOI: 10.1002/hbm.23415] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 08/24/2016] [Accepted: 09/21/2016] [Indexed: 01/06/2023] Open
Abstract
In mesial temporal lobe epilepsy (mTLE), the causal relationship of morphometric alterations between hippocampus and the other regions, that is, how the hippocampal atrophy leads to progressive morphometric alterations in the epileptic network regions remains largely unclear. In this study, a causal network of structural covariance (CaSCN) was proposed to map the causal effects of hippocampal atrophy on the network-based morphometric alterations in mTLE. It was hypothesized that if cross-sectional morphometric MRI data could be attributed temporal information, for example, by sequencing the data according to disease progression information, GCA would be a feasible approach for constructing a CaSCN. Based on a large cohort of mTLE patients (n = 108), the hippocampus-associated CaSCN revealed that the hippocampus and the thalamus were prominent nodes exerting causal effects (i.e., GM reduction) on other regions and that the prefrontal cortex and cerebellum were prominent nodes being subject to causal effects. Intriguingly, compensatory increased gray matter volume in the contralateral temporal region and post cingulate cortex were also detected. The method unraveled richer information for mapping network atrophy in mTLE relative to the traditional methods of stage-specific comparisons and structured covariance network. This study provided new evidence on the network spread mechanism in terms of the causal influence of hippocampal atrophy on progressive brain structural alterations in mTLE. Hum Brain Mapp 38:753-766, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Zhiqiang Zhang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.,State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, 210093, China
| | - Wei Liao
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.,Center for Cognition and Brain Disorders, Affiliated Hospital of Hangzhou Normal University, Hangzhou, 310015, China
| | - Qiang Xu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Wei Wei
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Helen Juan Zhou
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
| | - Kangjian Sun
- Department of Neurosurgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Fang Yang
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Dante Mantini
- Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Belgium
| | - Xueman Ji
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Guangming Lu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.,State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, 210093, China
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28
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Liu HH, Wang J, Chen XM, Li JP, Ye W, Zheng J. Reduced local diffusion homogeneity as a biomarker for temporal lobe epilepsy. Medicine (Baltimore) 2016; 95:e4032. [PMID: 27472676 PMCID: PMC5265813 DOI: 10.1097/md.0000000000004032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In the present study, we adopted a novel method-local diffusion homogeneity (LDH)-to characterize the structure feature in mesial temporal lobe epilepsy (MTLE). Diffusion-weighted images were acquired from 11 left MTLE patients, 16 right MTLE patients, and 20 healthy controls from May 2014 to January 2015. Local diffusion homogeneity was compared among patient groups and controls by 2 sample t test. The discriminative value of LDH abnormalities was examined by receiver operating characteristic (ROC) curve analysis. Correlations with disease duration and onset age in both patient groups were assessed using Pearson's coefficient. Both patient groups exhibited lower LDH in the anterior corpus callosum (P < 0.05, corrected), and this regional anomaly exhibited excellent classification performance in left MTLE patients (sensitivity = 82%, specificity = 100%), right MTLE patients (sensitivity = 81%, specificity = 90%), and the entire patient cohort (sensitivity = 82%, specificity = 95%). In summary, left and right MTLE patients show common pathological changes in the anterior corpus callosum. This regional LDH abnormality is a potential quantitative biomarker for MTLE.
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Affiliation(s)
- Hui-hua Liu
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning
- Department of Neurology, the Nanxishan Hospital of Guangxi Zhuang Autonomous Region, Guilin
| | - Jun Wang
- Department of Neurology, the Nanxishan Hospital of Guangxi Zhuang Autonomous Region, Guilin
| | - Xue-mei Chen
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning
| | - Jian-ping Li
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning
| | - Wei Ye
- Department of Radiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jinou Zheng
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning
- Correspondence: Jinou Zheng, Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (e-mail: )
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29
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Li K, Laird AR, Price LR, McKay DR, Blangero J, Glahn DC, Fox PT. Progressive Bidirectional Age-Related Changes in Default Mode Network Effective Connectivity across Six Decades. Front Aging Neurosci 2016; 8:137. [PMID: 27378909 PMCID: PMC4905965 DOI: 10.3389/fnagi.2016.00137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/27/2016] [Indexed: 12/31/2022] Open
Abstract
The default mode network (DMN) is a set of regions that is tonically engaged during the resting state and exhibits task-related deactivation that is readily reproducible across a wide range of paradigms and modalities. The DMN has been implicated in numerous disorders of cognition and, in particular, in disorders exhibiting age-related cognitive decline. Despite these observations, investigations of the DMN in normal aging are scant. Here, we used blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) acquired during rest to investigate age-related changes in functional connectivity of the DMN in 120 healthy normal volunteers comprising six, 20-subject, decade cohorts (from 20–29 to 70–79). Structural equation modeling (SEM) was used to assess age-related changes in inter-regional connectivity within the DMN. SEM was applied both using a previously published, meta-analytically derived, node-and-edge model, and using exploratory modeling searching for connections that optimized model fit improvement. Although the two models were highly similar (only 3 of 13 paths differed), the sample demonstrated significantly better fit with the exploratory model. For this reason, the exploratory model was used to assess age-related changes across the decade cohorts. Progressive, highly significant changes in path weights were found in 8 (of 13) paths: four rising, and four falling (most changes were significant by the third or fourth decade). In all cases, rising paths and falling paths projected in pairs onto the same nodes, suggesting compensatory increases associated with age-related decreases. This study demonstrates that age-related changes in DMN physiology (inter-regional connectivity) are bidirectional, progressive, of early onset and part of normal aging.
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Affiliation(s)
- Karl Li
- Research Imaging Institute, University of Texas Health Science Center San Antonio San Antonio, TX, USA
| | - Angela R Laird
- Department of Physics, Florida International University Miami, FL, USA
| | - Larry R Price
- Department of Mathematics and College of Education, Texas State University San Marcos, TX, USA
| | - D Reese McKay
- Department of Psychiatry, Yale University School of MedicineNew Haven, CT, USA; Olin Neuropsychiatry Research Center, Institute of Living, Hartford HospitalHartford, CT, USA
| | - John Blangero
- Genomics Computing Center, South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine Edinburg, TX, USA
| | - David C Glahn
- Department of Psychiatry, Yale University School of MedicineNew Haven, CT, USA; Olin Neuropsychiatry Research Center, Institute of Living, Hartford HospitalHartford, CT, USA
| | - Peter T Fox
- Research Imaging Institute, University of Texas Health Science Center San AntonioSan Antonio, TX, USA; Research Service, South Texas Veterans Health Care SystemSan Antonio, TX, USA; Neuroimaging Laboratory, Shenzhen University School of MedicineShenzhen, Guangdong, China
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30
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Luo C, Yang F, Deng J, Zhang Y, Hou C, Huang Y, Cao W, Wang J, Xiao R, Zeng N, Wang X, Yao D. Altered functional and effective connectivity in anticorrelated intrinsic networks in children with benign childhood epilepsy with centrotemporal spikes. Medicine (Baltimore) 2016; 95:e3831. [PMID: 27310959 PMCID: PMC4998445 DOI: 10.1097/md.0000000000003831] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
There are 2 intrinsic networks in the human brain: the task positive network (TPN) and task negative network (alternately termed the default mode network, DMN) in which inverse correlations have been observed during resting state and event-related functional magnetic resonance imaging (fMRI). The antagonism between the 2 networks might indicate a dynamic interaction in the brain that is associated with development.To evaluate the alterations in the relations of the 2 networks in children with benign childhood epilepsy with centrotemporal spikes (BECTS), resting state fMRI was performed in 17 patients with BECTS and 17 healthy controls. The functional and effective connectivities of 29 nodes in the TPN and DMN were analyzed. Positive functional connectivity (FC) within the networks and negative FC between the 2 networks were observed in both groups.The patients exhibited increased FC within both networks, particularly in the frontoparietal nodes such as the left superior frontal cortex, and enhanced antagonism between the 2 networks, suggesting abnormal functional integration of the nodes of the 2 networks in the patients. Granger causality analysis revealed a significant difference in the degree of outflow to inflow in the left superior frontal cortex and the left ventral occipital lobe.The alterations observed in the combined functional and effective connectivity analyses might indicate an association of an abnormal ability to integrate information between the DMN and TPN and the epileptic neuropathology of BECTS and provide preliminary evidence supporting the occurrence of abnormal development in children with BECTS.
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Affiliation(s)
- Cheng Luo
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu
| | | | - Jiayan Deng
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu
| | | | - Changyue Hou
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu
| | | | - Weifang Cao
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu
| | | | - Ruhui Xiao
- Radiology Department, Affiliated Hospital of North Sichuan Medical College, North Sichuan Medical College, Nanchong, China
| | - Nanlin Zeng
- Radiology Department, Affiliated Hospital of North Sichuan Medical College, North Sichuan Medical College, Nanchong, China
| | | | - Dezhong Yao
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu
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31
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Early life stress affects limited regional brain activity in depression. Sci Rep 2016; 6:25338. [PMID: 27138376 PMCID: PMC4853783 DOI: 10.1038/srep25338] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 04/13/2016] [Indexed: 12/13/2022] Open
Abstract
Early life stress (ELS) can alter brain function and increases the risk of major depressive disorder (MDD) in later life. This study investigated whether ELS contributes to differences in regional brain activity between MDD patients and healthy controls (HC), as measured by amplitude of low-frequency fluctuation (ALFF)/fractional (f)ALFF. Eighteen first-episode, treatment-naïve MDD patients and HC were assessed with the Childhood Trauma Questionnaire and resting-state functional magnetic resonance imaging. We compared ALFF/fALFF between MDD patients and HC, with or without controlling for ELS, and determined whether ELS level was correlated with regional brain activity in each group. After regressing out ELS, we found that ALFF increased in bilateral amygdala and left orbital/cerebellum, while fALFF decreased in left inferior temporal and right middle frontal gyri in MDD patients relative to controls. ELS positively correlated with regional activity in the left cerebellum in MDD and in the right post-central/inferior temporal/superior frontal cingulate, inferior frontal gyrus and bilateral cerebellum in HC. Our findings indicate that there is only very limited region showing correlation between ELS and brain activity in MDD, while diverse areas in HC, suggesting ELS has few impacts on MDD patients.
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32
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Functional Connectome before and following Temporal Lobectomy in Mesial Temporal Lobe Epilepsy. Sci Rep 2016; 6:23153. [PMID: 27001417 PMCID: PMC4802388 DOI: 10.1038/srep23153] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/29/2016] [Indexed: 01/05/2023] Open
Abstract
As mesial temporal lobe epilepsy (mTLE) has been recognized as a network disorder, a longitudinal connectome investigation may shed new light on the understanding of the underlying pathophysiology related to distinct surgical outcomes. Resting-state functional MRI data was acquired from mTLE patients before (n = 37) and after (n = 24) anterior temporal lobectomy. According to surgical outcome, patients were classified as seizure-free (SF, n = 14) or non-seizure-free (NSF, n = 10). First, we found higher network resilience to targeted attack on topologically central nodes in the SF group compared to the NSF group, preoperatively. Next, a two-way mixed analysis of variance with between-subject factor ‘outcome’ (SF vs. NSF) and within-subject factor ‘treatment’ (pre-operation vs. post-operation) revealed divergent dynamic reorganization in nodal topological characteristics between groups, in the temporoparietal junction and its connection with the ventral prefrontal cortex. We also correlated the network damage score (caused by surgical resection) with postsurgical brain function, and found that the damage score negatively correlated with postoperative global and local parallel information processing. Taken together, dynamic connectomic architecture provides vital information for selecting surgical candidates and for understanding brain recovery mechanisms following epilepsy surgery.
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Wei W, Zhang Z, Xu Q, Yang F, Sun K, Lu G. More Severe Extratemporal Damages in Mesial Temporal Lobe Epilepsy With Hippocampal Sclerosis Than That With Other Lesions: A Multimodality MRI Study. Medicine (Baltimore) 2016; 95:e3020. [PMID: 26962820 PMCID: PMC4998901 DOI: 10.1097/md.0000000000003020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS) presents different clinical presentations from that with other lesions (OL). It is significant to investigate the neural mechanism underlying the different clinical presentations using neuroimaging study.Thirty mTLE patients with mTLE-HS, 30 mTLE patients with other lesions (mTLE-OL), and 30 age- and sex-matched healthy controls were involved. Amplitude of low-frequency fluctuation (ALFF) analysis-based resting-state functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM) based morphometric MRI were employed to describing functional and structural imaging alterations in mTLE. Imaging parameters of ALFF and gray matter volume (GMV) were compared among groups and correlated with clinical variables and cognitive scores.For parameter of ALFF, both patient groups of mTLE-HS and mTLE-OL showed decrease in the frontal cortices relative to the healthy controls; mTLE-HS showed more decrease in the prefrontal and brain default regions relative to mTLE-OL. For GMV, both patient groups showed decrease in the frontal cortex, thalamus, and cerebellum; mTLE-HS showed more GMV decrease relative to the mTLE-OL, also mainly in the prefrontal and brain default regions. In both patient groups, the prefrontal regions showed negative correlation between GMV and epilepsy duration.This work revealed distinct alteration patterns of functional and structural brain organizations in mTLEs with different forms. MTLE-HS, despite with smaller lesion size of the pathological focus, presented more severe functional and structural damages in the extratemporal regions than mTLE-OL. The findings provided imaging evidence to support the proposal that mTLE-HS is a special epilepsy syndrome.
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Affiliation(s)
- Wei Wei
- From the Department of Medical Imaging (WW, ZZ, QX, GL), Department of Neurology (QX), Department of Neurosurgery (FY), Jinling Hospital, Nanjing University School of Medicine, and State Key Laboratory of Analytical Chemistry for Life Science (ZZ, GL), Nanjing University, Nanjing, China
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34
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Chen J, Fan C, Li J, Han Q, Lin J, Yang T, Zhang J. Increased Intraregional Synchronized Neural Activity in Adult Brain After Prolonged Adaptation to High-Altitude Hypoxia: A Resting-State fMRI Study. High Alt Med Biol 2016; 17:16-24. [PMID: 26906285 DOI: 10.1089/ham.2015.0104] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The human brain is intrinsically plastic such that its functional architecture can be reorganized in response to environmental pressures and physiological changes. However, it remains unclear whether a compensatory modification of spontaneous neural activity occurs in adult brain during prolonged high-altitude (HA) adaptation. In this study, we obtained resting-state functional magnetic resonance (MR) images in 16 adults who have immigrated to Qinghai-Tibet Plateau (2300-4400 m) for 2 years and in 16 age-matched sea level (SL) controls. A validated regional homogeneity (Reho) method was employed to investigate the local synchronization of resting-state functional magnetic resonance imaging (fMRI) signals. Seed connectivity analysis was carried out subsequently. Cognitive and physiological assessments were made and correlated with the image metrics. Compared with SL controls, global mean Reho was significantly increased in HA immigrants as well as a regional increase in the right inferolateral sensorimotor cortex. Furthermore, mean z-Reho value extracted within the inferolateral sensorimotor area showed trend-level significant inverse correlation with memory search reaction time in HA immigrants. These observations, for the first time, provide evidence of adult brain resilience of spontaneous neural activity after long-term HA exposure without inherited and developmental effects. Resting-state fMRI could yield valuable information for central mechanisms underlying respiratory and cognitive compensations in adults during prolonged environmentally hypoxic adaptation, paving the way for future HA-adaptive training.
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Affiliation(s)
- Ji Chen
- 1 Department of Physiology and Neurobiology, Medical College of Xiamen University , Xiamen, Fujian, China .,2 Department of Medical Imaging Center, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA , Fuzhou, Fujian, China
| | - Cunxiu Fan
- 1 Department of Physiology and Neurobiology, Medical College of Xiamen University , Xiamen, Fujian, China
| | - Jinqiang Li
- 3 Department of Clinical Psychology, Gulangyu Sanatorium of PLA , Xiamen, Fujian, China
| | - Qiaoqing Han
- 3 Department of Clinical Psychology, Gulangyu Sanatorium of PLA , Xiamen, Fujian, China
| | - Jianzhong Lin
- 4 Magnetic Resonance Center, Zhongshan Hospital, Medical College of Xiamen University , Xiamen, Fujian, China
| | - Tianhe Yang
- 4 Magnetic Resonance Center, Zhongshan Hospital, Medical College of Xiamen University , Xiamen, Fujian, China
| | - Jiaxing Zhang
- 1 Department of Physiology and Neurobiology, Medical College of Xiamen University , Xiamen, Fujian, China
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35
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Feng Z, Xu S, Huang M, Shi Y, Xiong B, Yang H. Disrupted causal connectivity anchored on the anterior cingulate cortex in first-episode medication-naive major depressive disorder. Prog Neuropsychopharmacol Biol Psychiatry 2016; 64:124-30. [PMID: 26234517 DOI: 10.1016/j.pnpbp.2015.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Revised: 07/07/2015] [Accepted: 07/23/2015] [Indexed: 12/30/2022]
Abstract
In recent years, major depressive disorder (MDD) has been demonstrated to be associated with abnormalities in neural networks, particularly the prefrontal-limbic network (PLN). However, there are few current studies that have examined information flow in the PLN. In this study, Granger causality analysis (GCA), based on signed regression coefficient, was used to explore changes in causal connectivity in resting-state PLNs of MDD patients. A total of 23 first-episode medication-naïve MDD patients and 20 normal control participants were subjected to resting-state functional magnetic resonance imaging (RS-fMRI) scans. Increased causal effects of the right insular cortex, right putamen and right caudate on the rostral anterior cingulate cortex (rACC) and reduced causal effects of bilateral dorsolateral prefrontal cortex (DLPFC) and left orbitofrontal cortex (OFC) on the rACC were found in MDD patients compared to normal controls. The extensive reduction in the causal effect of the prefrontal cortex (PFC) demonstrates impaired top-down cognitive control in MDD patients. Changes in the causal relationship between the right insula and rACC suggest problems in coordination of the default mode network by the right anterior insular cortex (rAI). These findings provide valuable insight into MDD-related neural network disorders reported in previous RS-fMRI studies and may potentially guide clinical treatment of MDD in the future.
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Affiliation(s)
- Zhan Feng
- Department of Radiology, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China; The key laboratory of mental disorder's management of Zhejiang Province, Hangzhou, Zhejiang, China
| | - Shunliang Xu
- Department of Radiology, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Manli Huang
- Department of Psychiatry, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China; The key laboratory of mental disorder's management of Zhejiang Province, Hangzhou, Zhejiang, China
| | - Yushu Shi
- Department of Radiology, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Bing Xiong
- Department of Radiology, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hong Yang
- Department of Radiology, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China.
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36
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Modo M, Hitchens TK, Liu JR, Richardson RM. Detection of aberrant hippocampal mossy fiber connections: Ex vivo mesoscale diffusion MRI and microtractography with histological validation in a patient with uncontrolled temporal lobe epilepsy. Hum Brain Mapp 2015; 37:780-95. [PMID: 26611565 PMCID: PMC4718824 DOI: 10.1002/hbm.23066] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 10/30/2015] [Accepted: 11/16/2015] [Indexed: 12/28/2022] Open
Abstract
Understanding the neurobiology and functional connectivity of hippocampal structures is essential for improving the treatment of mesial temporal lobe epilepsy. At the macroscale, in vivo MRI often reveals hippocampal atrophy and decreased fractional anisotropy, whereas at the microscopic scale, there frequently is evidence of neuronal loss and gliosis. Mossy fiber sprouting in the dentate gyrus (DG), with evidence of glutamatergic synapses in the stratum moleculare (SM) putatively originating from granule cell neurons, may also be observed. This aberrant connection between the DG and SM could produce a reverberant excitatory circuit. However, this hypothesis cannot easily be evaluated using macroscopic or microscopic techniques. We here demonstrate that the ex vivo mesoscopic MRI of surgically excised hippocampi can bridge the explanatory and analytical gap between the macro‐ and microscopic scale. Specifically, diffusion‐ and T2‐weighted MRI can be integrated to visualize a cytoarchitecture that is akin to immunohistochemistry. An appropriate spatial resolution to discern individual cell layers can then be established. Processing of diffusion tensor images using tractography detects extra‐ and intrahippocampal connections, hence providing a unique systems view of the hippocampus and its connected regions. Here, this approach suggests that there is indeed an aberrant connection between the DG and SM, supporting the sprouting hypothesis of a reverberant excitatory network. Mesoscopic ex vivo MR imaging hence provides an exciting new avenue to study hippocampi from treatment‐resistant patients and allows exploration of existing hypotheses, as well as the development of new treatment strategies based on these novel insights. Hum Brain Mapp 37:780–795, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Michel Modo
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Centre for the Neural Basis of Behavior, Pittsburgh, Pennsylvania
| | - T Kevin Hitchens
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jessie R Liu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - R Mark Richardson
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Centre for the Neural Basis of Behavior, Pittsburgh, Pennsylvania.,Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
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37
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Hu Y, Mi X, Xu X, Fang W, Zeng K, Yang M, Li C, Wang S, Li M, Wang X. The Brain Activity in Brodmann Area 17: A Potential Bio-Marker to Predict Patient Responses to Antiepileptic Drugs. PLoS One 2015; 10:e0139819. [PMID: 26439500 PMCID: PMC4595505 DOI: 10.1371/journal.pone.0139819] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 07/28/2015] [Indexed: 12/29/2022] Open
Abstract
In this study, we aimed to predict newly diagnosed patient responses to antiepileptic drugs (AEDs) using resting-state functional magnetic resonance imaging tools to explore changes in spontaneous brain activity. We recruited 21 newly diagnosed epileptic patients, 8 drug-resistant (DR) patients, 11 well-healed (WH) patients, and 13 healthy controls. After a 12-month follow-up, 11 newly diagnosed epileptic patients who showed a poor response to AEDs were placed into the seizures uncontrolled (SUC) group, while 10 patients were enrolled in the seizure-controlled (SC) group. By calculating the amplitude of fractional low-frequency fluctuations (fALFF) of blood oxygen level-dependent signals to measure brain activity during rest, we found that the SUC patients showed increased activity in the bilateral occipital lobe, particularly in the cuneus and lingual gyrus compared with the SC group and healthy controls. Interestingly, DR patients also showed increased activity in the identical cuneus and lingual gyrus regions, which comprise Brodmann's area 17 (BA17), compared with the SUC patients; however, these abnormalities were not observed in SC and WH patients. The receiver operating characteristic (ROC) curves indicated that the fALFF value of BA17 could differentiate SUC patients from SC patients and healthy controls with sufficient sensitivity and specificity prior to the administration of medication. Functional connectivity analysis was subsequently performed to evaluate the difference in connectivity between BA17 and other brain regions in the SUC, SC and control groups. Regions nearby the cuneus and lingual gyrus were found positive connectivity increased changes or positive connectivity changes with BA17 in the SUC patients, while remarkably negative connectivity increased changes or positive connectivity decreased changes were found in the SC patients. Additionally, default mode network (DMN) regions showed negative connectivity increased changes or negative changes with BA17 in the SUC patients. The abnormal increased in BA17 activity may be a key point that plays a substantial role in facilitating seizure onset.
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Affiliation(s)
- Yida Hu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
| | - Xiujuan Mi
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
| | - Xin Xu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
| | - Weidong Fang
- Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
| | - Kebin Zeng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
| | - Mingming Yang
- Department of Pediatrics, Chongqing City Hospital of Traditional Chinese Medicine, Chongqing, People’s Republic of China
| | - Chenyu Li
- Department of Neurology, Chongqing City Hospital of Traditional Chinese Medicine, Chongqing, People’s Republic of China
| | - Shasha Wang
- The Nursing Department, Chongqing Three Gorges Central Hospital, Chongqing, People’s Republic of China
| | - Minghui Li
- The Nursing Department, First Hospital of Shanxi Medical University, Taiyuan, People’s Republic of China
| | - Xuefeng Wang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
- * E-mail:
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38
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Ji GJ, Zhang Z, Xu Q, Wei W, Wang J, Wang Z, Yang F, Sun K, Jiao Q, Liao W, Lu G. Connectome Reorganization Associated With Surgical Outcome in Temporal Lobe Epilepsy. Medicine (Baltimore) 2015; 94:e1737. [PMID: 26448031 PMCID: PMC4616737 DOI: 10.1097/md.0000000000001737] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
To identify the distinct pattern of anatomical network reorganization in surgically refractory mesial temporal lobe epilepsy (MTLE) patients using a longitudinal design. We collected longitudinal diffusion-weighted images of 19 MTLE patients before and after anterior temporal lobectomy. Patients were classified as seizure-free (SF) or nonseizure-free (NSF) at least 1 year after surgery. We constructed whole-brain anatomical networks derived from white matter tractography and evaluated network connectivity measures by graph theoretical analysis. The reorganization trajectories of network measures in SF and NSF patients were investigated by two-way mixed analysis of variance, with factors "group" (SF vs NSF) and "treatment" (presurgery vs postsurgery). Widespread brain structures showed opposite reorganization trajectories in FS and NSF groups (interaction effect). Most of them showed group difference before surgery and then converge after surgery, suggesting that surgery remodeled these structures into a similar status. Conversly, contralateral amygdala-planum-temporale and thalamic-parietal tracts showed higher connectivity strength in NSF than in SF patients after surgery, indicating maladaptive neuroplastic responses to surgery in NSF patients. Our findings suggest that surgical outcomes are associated not only with the preoperative pattern of anatomical connectivity, but also with connectome reconfiguration following surgery. The reorganization of contralateral temporal lobe and corticothalamic tracts may be particularly important for seizure control in MTLE.
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Affiliation(s)
- Gong-Jun Ji
- From the Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei (G-JJ); Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University (G-JJ, JW, WL); Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou (G-JJ, JW, WL); Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine (ZZ, QX, WW, GL); Department of Medical Imaging, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School (ZW); Department of Neurology, Jinling Hospital (FY); Department of Neurosurgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing (KS); Department of Radiology, Taishan Medical University, Tai'an (QJ); and Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China (WL)
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Guo W, Liu F, Xiao C, Yu M, Zhang Z, Liu J, Zhang J, Zhao J. Increased Causal Connectivity Related to Anatomical Alterations as Potential Endophenotypes for Schizophrenia. Medicine (Baltimore) 2015; 94:e1493. [PMID: 26496253 PMCID: PMC4620791 DOI: 10.1097/md.0000000000001493] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Anatomical and functional abnormalities in the cortico-cerebellar-thalamo-cortical circuit have been observed in schizophrenia patients and their unaffected siblings. However, it remains unclear to the relationship between anatomical and functional abnormalities within this circuit in schizophrenia patients and their unaffected siblings, which may serve as potential endophenotypes for schizophrenia.Anatomical and resting-state functional magnetic resonance imaging data were acquired from 49 first-episode, drug-naive schizophrenia patients, 46 unaffected siblings, and 46 healthy controls. Data were analyzed by using voxel-based morphometry and Granger causality analysis.The patients and the siblings shared anatomical deficits in the left middle temporal gyrus (MTG) and increased left MTG-left angular gyrus (AG) connectivity. Moreover, the left MTG-left AG connectivity negatively correlates to the duration of untreated psychosis in the patients.The findings indicate that anatomical deficits in the left MTG and its increased causal connectivity with the left AG may serve as potential endophenotypes for schizophrenia with clinical implications.
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Affiliation(s)
- Wenbin Guo
- From the Mental Health Institute of the Second Xiangya Hospital, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, Hunan (GW, ZJ); Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan (LF); and Mental Health Center, The First Affiliated Hospital, Guangxi Medical University; Nanning, Guangxi, China (XC, YM, ZZ, LJ, ZJ)
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40
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Wu Y, Ji GJ, Li K, Jin Z, Liu YL, Zeng YW, Fang F. Interhemispheric Connectivity in Drug-Naive Benign Childhood Epilepsy With Centrotemporal Spikes: Combining Function and Diffusion MRI. Medicine (Baltimore) 2015; 94:e1550. [PMID: 26376406 PMCID: PMC4635820 DOI: 10.1097/md.0000000000001550] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Decreased intelligence quotients (IQ) have been consistently reported in drug-naive benign childhood epilepsy with centrotemporal spikes (BECTS). We aimed to identify the neurophysiological basis of IQ deficits by studying interhemispheric and anatomical functional connectivity in BECTS patients. Resting-state functional and structural magnetic resonance images were acquired in 32 children with BECTS and 25 healthy controls. The IQ was estimated using Wechsler Intelligence Scale for Children China-Revised. The functional connectivity between bilateral homotopic voxels was calculated and compared between groups. Homotopic regions showing abnormal functional connectivity in patients were adopted as regions of interest for analysis by diffusion-tensor imaging tractography. The fractional anisotropy, fiber length, and fiber number were compared between groups. Abnormal homotopic connectivities were correlated with IQ in BECTS patients. Compared with control subjects, patients showed decreased IQ, and decreased voxel-mirrored homotopic connectivity (VMHC) in the bilateral frontal lobule and cerebellum. The performance and full scale IQ significantly increased with the VMHC strength of the middle frontal gyrus (MFG) in controls but not in BECTS patients. A significant negative correlation was observed between VMHC in the premotor cortex and disease duration. Microstructural features within white matter tracts connecting functionally abnormal regions did not reveal any differences between groups. This study provides preliminary evidence for the disrupted functional cooperation between hemispheres in children with BECTS. The findings suggest that the hyposynchrony between the bilateral MFG may be involved in the decreased IQ of BECTS patients.
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Affiliation(s)
- Yun Wu
- From Department of Neurology, Beijing Children's Hospital Affiliated to Capital Medical University, Beijing, China (YW, FF), Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China (GJJ), Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China (GJJ), Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, Zhejiang, China (GJJ), fMRI Center, The 306 Hospital of People's Liberation Army, Beijing, China (KL, ZJ, YLL, YWZ)
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41
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Yang Z, Choupan J, Reutens D, Hocking J. Lateralization of Temporal Lobe Epilepsy Based on Resting-State Functional Magnetic Resonance Imaging and Machine Learning. Front Neurol 2015; 6:184. [PMID: 26379618 PMCID: PMC4553409 DOI: 10.3389/fneur.2015.00184] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 08/10/2015] [Indexed: 11/13/2022] Open
Abstract
Lateralization of temporal lobe epilepsy (TLE) is critical for successful outcome of surgery to relieve seizures. TLE affects brain regions beyond the temporal lobes and has been associated with aberrant brain networks, based on evidence from functional magnetic resonance imaging. We present here a machine learning-based method for determining the laterality of TLE, using features extracted from resting-state functional connectivity of the brain. A comprehensive feature space was constructed to include network properties within local brain regions, between brain regions, and across the whole network. Feature selection was performed based on random forest and a support vector machine was employed to train a linear model to predict the laterality of TLE on unseen patients. A leave-one-patient-out cross validation was carried out on 12 patients and a prediction accuracy of 83% was achieved. The importance of selected features was analyzed to demonstrate the contribution of resting-state connectivity attributes at voxel, region, and network levels to TLE lateralization.
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Affiliation(s)
- Zhengyi Yang
- School of Information Technology and Electrical Engineering, The University of Queensland , Brisbane, QLD , Australia ; Centre for Advanced Imaging, The University of Queensland , Brisbane, QLD , Australia
| | - Jeiran Choupan
- Centre for Advanced Imaging, The University of Queensland , Brisbane, QLD , Australia ; Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia
| | - David Reutens
- Centre for Advanced Imaging, The University of Queensland , Brisbane, QLD , Australia
| | - Julia Hocking
- School of Psychology and Counselling, Queensland University of Technology , Brisbane, QLD , Australia
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42
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Rajpoot K, Riaz A, Majeed W, Rajpoot N. Functional Connectivity Alterations in Epilepsy from Resting-State Functional MRI. PLoS One 2015; 10:e0134944. [PMID: 26252668 PMCID: PMC4529140 DOI: 10.1371/journal.pone.0134944] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 07/15/2015] [Indexed: 12/24/2022] Open
Abstract
The study of functional brain connectivity alterations induced by neurological disorders and their analysis from resting state functional Magnetic Resonance Imaging (rfMRI) is generally considered to be a challenging task. The main challenge lies in determining and interpreting the large-scale connectivity of brain regions when studying neurological disorders such as epilepsy. We tackle this challenging task by studying the cortical region connectivity using a novel approach for clustering the rfMRI time series signals and by identifying discriminant functional connections using a novel difference statistic measure. The proposed approach is then used in conjunction with the difference statistic to conduct automatic classification experiments for epileptic and healthy subjects using the rfMRI data. Our results show that the proposed difference statistic measure has the potential to extract promising discriminant neuroimaging markers. The extracted neuroimaging markers yield 93.08% classification accuracy on unseen data as compared to 80.20% accuracy on the same dataset by a recent state-of-the-art algorithm. The results demonstrate that for epilepsy the proposed approach confirms known functional connectivity alterations between cortical regions, reveals some new connectivity alterations, suggests potential neuroimaging markers, and predicts epilepsy with high accuracy from rfMRI scans.
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Affiliation(s)
- Kashif Rajpoot
- College of Computer Science & Information Technology, King Faisal University, Al Ahsa, Kingdom of Saudi Arabia
- School of Electrical Engineering and Computer Science, National University of Sciences & Technology, Islamabad, Pakistan
- * E-mail:
| | - Atif Riaz
- School of Electrical Engineering and Computer Science, National University of Sciences & Technology, Islamabad, Pakistan
| | - Waqas Majeed
- School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Nasir Rajpoot
- Department of Computer Science & Engineering, Qatar University, Doha, Qatar
- Department of Computer Science, University of Warwick, Coventry, United Kingdom
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43
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Distributions of Irritative Zones Are Related to Individual Alterations of Resting-State Networks in Focal Epilepsy. PLoS One 2015; 10:e0134352. [PMID: 26226628 PMCID: PMC4520590 DOI: 10.1371/journal.pone.0134352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 07/09/2015] [Indexed: 01/04/2023] Open
Abstract
Alterations in the connectivity patterns of the fMRI-based resting-state networks (RSNs) have been reported in several types of epilepsies. Evidence pointed out these alterations might be associated with the genesis and propagation of interictal epileptiform discharges (IEDs). IEDs also evoke blood-oxygen-level dependent (BOLD) responses, which have been used to delineate irritative zones during preoperative work-up. Therefore, one may expect a relationship between the topology of the IED-evoked BOLD response network and the altered spatial patterns of the RSNs. In this study, we used EEG recordings and fMRI data obtained simultaneously from a chronic model of focal epilepsy in Wistar rats to verify our hypothesis. We found that IED-evoked BOLD response networks comprise both cortical and subcortical structures with a rat-dependent topology. In all rats, IEDs evoke both activation and deactivation types of BOLD responses. Using a Granger causality method, we found that in many cases areas with BOLD deactivation have directed influences on areas with activation (p<0.05). We were able to predict topological properties (i.e., focal/diffused, unilateral/bilateral) of the IED-evoked BOLD response network by performing hierarchical clustering analysis on major spatial features of the RSNs. All these results suggest that IEDs and disruptions in the RSNs found previously in humans may be different manifestations of the same transient events, probably reflecting altered consciousness. In our opinion, the shutdown of specific nodes of the default mode network may cause uncontrollable excitability in other functionally connected brain areas. We conclude that IED-evoked BOLD responses (i.e., activation and deactivation) and alterations of RSNs are intrinsically related, and speculate that an understanding of their interplay is necessary to discriminate focal epileptogenesis and network propagation phenomena across different brain modules via hub-based connectivity.
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Wu Y, Ji GJ, Zang YF, Liao W, Jin Z, Liu YL, Li K, Zeng YW, Fang F. Local Activity and Causal Connectivity in Children with Benign Epilepsy with Centrotemporal Spikes. PLoS One 2015. [PMID: 26225427 PMCID: PMC4520539 DOI: 10.1371/journal.pone.0134361] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The aim of the current study was to localize the epileptic focus and characterize its causal relation with other brain regions, to understand the cognitive deficits in children with benign childhood epilepsy with centrotemporal spikes (BECTS). Resting-state functional magnetic resonance imaging (fMRI) was performed in 37 children with BECTS and 25 children matched for age, sex and educational achievement. We identified the potential epileptogenic zone (EZ) by comparing the amplitude of low frequency fluctuation (ALFF) of spontaneous blood oxygenation level dependent fMRI signals between the groups. Granger causality analysis was applied to explore the causal effect between EZ and the whole brain. Compared with controls, children with BECTS had significantly increased ALFF in the right postcentral gyrus and bilateral calcarine, and decreased ALFF in the left anterior cingulate cortex, bilateral putaman/caudate, and left cerebellum. ALFF values in the putaman/caudate were positively correlated with verbal IQ scores in patients. The ALFF values in cerebellum and performance IQ scores were negatively correlated in patients. These results suggest that ALFF disturbances in the putaman/caudate and cerebellum play an important role in BECTS cognitive dysfunction. Compared with controls, the patients showed increased driving effect from the EZ to the right medial frontal cortex and posterior cingulate cortex and decreased causal effects from the EZ to left inferior frontal gyrus. The causal effect of the left inferior frontal gyrus negatively correlated with disease duration, which suggests a relation between the epileptiform activity and language impairment. All together, these findings provide additional insight into the neurophysiological mechanisms of epilepitogenisis and cognitive dysfunction associated with BECTS.
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Affiliation(s)
- Yun Wu
- Department of Neurology, Beijing Children’s Hospital Affiliated to Capital Medical University, Beijing, China
- * E-mail: (YW); (FF)
| | - Gong-Jun Ji
- Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Yu-Feng Zang
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Wei Liao
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Zhen Jin
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Ya-Li Liu
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Ke Li
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Ya-Wei Zeng
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Fang Fang
- Department of Neurology, Beijing Children’s Hospital Affiliated to Capital Medical University, Beijing, China
- * E-mail: (YW); (FF)
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45
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He X, Doucet GE, Sperling M, Sharan A, Tracy JI. Reduced thalamocortical functional connectivity in temporal lobe epilepsy. Epilepsia 2015; 56:1571-9. [PMID: 26193910 DOI: 10.1111/epi.13085] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2015] [Indexed: 01/06/2023]
Abstract
OBJECTIVE In temporal lobe epilepsy (TLE), the thalamus is well known for its role in the propagation and spread of epileptiform activity. However, the integrity of thalamocortical functional connectivity (FC) in TLE and its relation to specific seizure patterns have not yet been determined. We address these issues with resting-state functional magnetic resonance imaging (fMRI). METHODS Resting-state fMRI was performed on two groups of unilateral TLE patients: those with focal seizures only (16 left TLE, 16 right TLE) and those with additional generalized seizures (16 left TLE, 10 right TLE), and 16 matched controls. A thalamic parcellation based on FC between five nonoverlapping cortical seeds (prefrontal, motor, somatosensory, parietal-occipital, and temporal) and the ipsilateral thalamus was carried out to parcel each thalamus into five corresponding segments. FCs between each segment and its ipsilateral cortical seed were extracted and compared across groups using analyses of variance (ANOVAs). RESULTS Compared to healthy controls, patients with TLE displayed decreased thalamocortical FC in multiple posterior and ventromedial thalamic segments of both the ictal and nonictal hemispheres. Our parcellation analysis revealed that these thalamic regions were functionally connected to the parietal/occipital and temporal lobes. In patients with TLE with focal seizures these regional thalamocortical FC decreases were limited to the ictal hemisphere. In contrast, TLE patients with both focal and generalized epileptiform activity displayed FC decreases in both the ictal and nonictal thalamus involving the dorsolateral pulvinar, a region preferentially connected to the parietal and occipital lobes. SIGNIFICANCE Our data provide the first evidence of regional specific thalamocortical FC decreases in patients with unilateral TLE. Furthermore, our results demonstrate that patients with different seizure types present different thalamoparietal/occipital FC decrease patterns. While patients with focal seizures present thalamocortical FC decreases in the ictal hemisphere only, patients with additional generalized seizure activity also show thalamocortical FC decreases involving the thalamus in the nonictal hemisphere.
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Affiliation(s)
- Xiaosong He
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Gaelle E Doucet
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Michael Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Ashwini Sharan
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Joseph I Tracy
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
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46
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Zhu Y, Yu Y, Shinkareva SV, Ji GJ, Wang J, Wang ZJ, Zang YF, Liao W, Tang YL. Intrinsic brain activity as a diagnostic biomarker in children with benign epilepsy with centrotemporal spikes. Hum Brain Mapp 2015; 36:3878-89. [PMID: 26173095 DOI: 10.1002/hbm.22884] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 05/21/2015] [Accepted: 06/11/2015] [Indexed: 12/11/2022] Open
Abstract
Benign epilepsy with centrotemporal spikes (BECTS) is often associated with neural circuit dysfunction, particularly during the transient active state characterized by interictal epileptiform discharges (IEDs). Little is known, however, about the functional neural circuit abnormalities in BECTS without IEDs, or if such abnormalities could be used to differentiate BECTS patients without IEDs from healthy controls (HCs) for early diagnosis. To this end, we conducted resting-state functional magnetic resonance imaging (RS-fMRI) and simultaneous Electroencephalogram (EEG) in children with BECTS (n = 43) and age-matched HC (n = 28). The simultaneous EEG recordings distinguished BECTS with IEDs (n = 20) from without IEDs (n = 23). Intrinsic brain activity was measured in all three groups using the amplitude of low frequency fluctuation at rest. Compared to HC, BECTS patients with IEDs exhibited an intrinsic activity abnormality in the thalamus, suggesting that thalamic dysfunction could contribute to IED emergence while patients without IEDs exhibited intrinsic activity abnormalities in middle frontal gyrus and superior parietal gyrus. Using multivariate pattern classification analysis, we were able to differentiate BECTS without IEDs from HCs with 88.23% accuracy. BECTS without epileptic transients can be distinguished from HC and BECTS with IEDs by unique regional abnormalities in resting brain activity. Both transient abnormalities as reflected by IEDs and chronic abnormalities as reflected by RS-fMRI may contribute to BECTS development and expression. Intrinsic brain activity and multivariate pattern classification techniques are promising tools to diagnose and differentiate BECTS syndromes. Hum Brain Mapp 36:3878-3889, 2015. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Yihong Zhu
- Mental Health Education and Counseling Center, Zhejiang University, Zhejiang, China.,School of Public Health, Zhejiang University, Zhejiang, China
| | - Yang Yu
- Mental Health Education and Counseling Center, Zhejiang University, Zhejiang, China.,School of Public Health, Zhejiang University, Zhejiang, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Zhejiang, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Zhejiang, China.,Department of Psychiatry, the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China
| | | | - Gong-Jun Ji
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Zhejiang, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Zhejiang, China
| | - Jue Wang
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Zhejiang, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Zhejiang, China
| | - Zhong-Jin Wang
- Department of Neurology, the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China
| | - Yu-Feng Zang
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Zhejiang, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Zhejiang, China
| | - Wei Liao
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Zhejiang, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Zhejiang, China
| | - Ye-Lei Tang
- Department of Neurology, the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China
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47
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Qiu C, Feng Y, Meng Y, Liao W, Huang X, Lui S, Zhu C, Chen H, Gong Q, Zhang W. Analysis of Altered Baseline Brain Activity in Drug-Naive Adult Patients with Social Anxiety Disorder Using Resting-State Functional MRI. Psychiatry Investig 2015; 12. [PMID: 26207132 PMCID: PMC4504921 DOI: 10.4306/pi.2015.12.3.372] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE We hypothesize that the amplitude of low-frequency fluctuations (ALFF) is involved in the altered regional baseline brain function in social anxiety disorder (SAD). The aim of the study was to analyze the altered baseline brain activity in drug-naive adult patients with SAD. METHODS We investigated spontaneous and baseline brain activities by obtaining the resting-state functional magnetic resonance imaging data of 20 drug-naïve adult SAD patients and 19 healthy controls. Voxels were used to analyze the ALFF values using one- and two-sample t-tests. A post-hoc correlation of clinical symptoms was also performed. RESULTS Our findings show decreased ALFF in the bilateral insula, left medial superior frontal gyrus, left precuneus, left middle temporal gyrus, right middle temporal pole, and left fusiform gyrus of the SAD group. The SAD patients exhibited significantly increased ALFF in the right inferior temporal gyrus, right middle temporal gyrus, bilateral middle occipital gyrus, orbital superior frontal gyrus, right fusiform gyrus, right medial superior frontal gyrus, and left parahippocampal gyrus. Moreover, the Liebowitz Social Anxiety Scale results for the SAD patients were positively correlated with the mean Z values of the right middle occipital and right inferior occipital but showed a negative correlation with the mean Z values of the right superior temporal gyrus and right medial superior frontal gyrus. CONCLUSION These results of the altered regional baseline brain function in SAD suggest that the regions with abnormal spontaneous activities are involved in the underlying pathophysiology of SAD patients.
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Affiliation(s)
- Changjian Qiu
- Mental Health Center, West China Hospital of Sichuan University, Chengdu, PR China
| | - Yuan Feng
- Mental Health Center, West China Hospital of Sichuan University, Chengdu, PR China
- Depression Treatment Center, Beijing Anding Hospital, Capital Medical University, Beijing, PR China
| | - Yajing Meng
- Mental Health Center, West China Hospital of Sichuan University, Chengdu, PR China
| | - Wei Liao
- Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, PR China
| | - Xiaoqi Huang
- Department of Radiology, Huaxi MR Research Center (HMRRC), West China Hospital of Sichuan University, Chengdu, PR China
| | - Su Lui
- Department of Radiology, Huaxi MR Research Center (HMRRC), West China Hospital of Sichuan University, Chengdu, PR China
| | - Chunyan Zhu
- Mental Health Center, West China Hospital of Sichuan University, Chengdu, PR China
- Department of Psychiatry, Hangzhou Seventh People Hospital, Hangzhou, PR China
| | - Huafu Chen
- Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, PR China
| | - Qiyong Gong
- Department of Radiology, Huaxi MR Research Center (HMRRC), West China Hospital of Sichuan University, Chengdu, PR China
| | - Wei Zhang
- Mental Health Center, West China Hospital of Sichuan University, Chengdu, PR China
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48
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A prospective fMRI-based technique for localising the epileptogenic zone in presurgical evaluation of epilepsy. Neuroimage 2015; 113:329-39. [DOI: 10.1016/j.neuroimage.2015.03.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/02/2015] [Accepted: 03/06/2015] [Indexed: 11/17/2022] Open
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49
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Gregory AM, Nenert R, Allendorfer JB, Martin R, Kana RK, Szaflarski JP. The effect of medial temporal lobe epilepsy on visual memory encoding. Epilepsy Behav 2015; 46:173-84. [PMID: 25934583 DOI: 10.1016/j.yebeh.2015.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 03/03/2015] [Accepted: 03/07/2015] [Indexed: 11/30/2022]
Abstract
Effective visual memory encoding, a function important for everyday functioning, relies on episodic and semantic memory processes. In patients with medial temporal lobe epilepsy (MTLE), memory deficits are common as the structures typically involved in seizure generation are also involved in acquisition, maintenance, and retrieval of episodic memories. In this study, we used group independent component analysis (GICA) combined with Granger causality analysis to investigate the neuronal networks involved in visual memory encoding during a complex fMRI scene-encoding task in patients with left MTLE (LMTLE; N=28) and in patients with right MTLE (RMTLE; N=18). Additionally, we built models of memory encoding in LMTLE and RMTLE and compared them with a model of healthy memory encoding (Nenert et al., 2014). For those with LMTLE, we identified and retained for further analyses and model generation 7 ICA task-related components that were attributed to four different networks: the frontal and posterior components of the DMN, visual network, auditory-insular network, and an "other" network. For those with RMTLE, ICA produced 9 task-related components that were attributed to the somatosensory and cerebellar networks in addition to the same networks as in patients with LMTLE. Granger causality analysis revealed group differences in causality relations within the visual memory network and MTLE-related deviations from normal network function. Our results demonstrate differences in the networks for visual memory encoding between those with LMTLE and those with RMTLE. Consistent with previous studies, the organization of memory encoding is dependent on laterality of seizure focus and may be mediated by functional reorganization in chronic epilepsy. These differences may underlie the observed differences in memory abilities between patients with LMTLE and patients with RMTLE and highlight the modulating effects of epilepsy on the network for memory encoding.
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Affiliation(s)
- A M Gregory
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - R Nenert
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - J B Allendorfer
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of UAB Epilepsy Center, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - R Martin
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of UAB Epilepsy Center, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - R K Kana
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - J P Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of UAB Epilepsy Center, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA.
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50
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Zhang Z, Xu Q, Liao W, Wang Z, Li Q, Yang F, Zhang Z, Liu Y, Lu G. Pathological uncoupling between amplitude and connectivity of brain fluctuations in epilepsy. Hum Brain Mapp 2015; 36:2756-66. [PMID: 25879781 DOI: 10.1002/hbm.22805] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 03/23/2015] [Accepted: 03/23/2015] [Indexed: 11/11/2022] Open
Abstract
Amplitude and functional connectivity are two fundamental parameters for describing the spontaneous brain fluctuations. These two parameters present close coupling in physiological state, and present different alteration patterns in epilepsy revealed by functional MRI (fMRI). We hypothesized that the alteration of coupling between these two imaging parameters may be underpinned by specific pathological factors of epilepsy, and can be employed to improve the capability for epileptic focus detection. Forty-seven patients (26 left- and 21 right-sided) with mesial temporal lobe epilepsy (mTLE) and 32 healthy controls underwent resting-state fMRI scans. All patients were detected to have interictal epileptic discharges on simultaneous electroencephalograph (EEG) recordings. Amplitude-connectivity coupling was calculated by correlating amplitude and functional connectivity density of low-frequency brain fluctuations. We observed reduced amplitude-connectivity coupling associated with epileptic discharges in the mesial temporal regions in both groups of patients, and increased coupling associated with epilepsy durations in the posterior regions of the default-mode network in the right-sided patients. Moreover, we proposed a new index of amplitude subtracting connectivity, which elevated imaging contrast for differentiating the patients from the controls. The findings indicated that epileptic discharges and chronic damaging effect of epilepsy might both contribute to alterations of amplitude-connectivity coupling in different pivotal regions in mTLE. Investigation on imaging coupling provides synergistic approach for describing brain functional changing features in epilepsy.
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Affiliation(s)
- Zhiqiang Zhang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.,State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, China
| | - Qiang Xu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Wei Liao
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.,Center for Cognition and Brain Disorders, Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Zhengge Wang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Qian Li
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Fang Yang
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Zongjun Zhang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Yijun Liu
- Department of Psychiatry and Neuroscience, University of Florida, Gainesville, Florida
| | - Guangming Lu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.,State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, China
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