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Wachsmuth L, Hebbelmann L, Prade J, Kohnert LC, Lambers H, Lüttjohann A, Budde T, Hess A, Faber C. Epilepsy-related functional brain network alterations are already present at an early age in the GAERS rat model of genetic absence epilepsy. Front Neurol 2024; 15:1355862. [PMID: 38529038 PMCID: PMC10961455 DOI: 10.3389/fneur.2024.1355862] [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: 12/14/2023] [Accepted: 02/16/2024] [Indexed: 03/27/2024] Open
Abstract
Introduction Genetic Absence Epilepsy Rats from Strasbourg (GAERS) represent a model of genetic generalized epilepsy. The present longitudinal study in GAERS and age-matched non-epileptic controls (NEC) aimed to characterize the epileptic brain network using two functional measures, resting state-functional magnetic resonance imaging (rs-fMRI) and manganese-enhanced MRI (MEMRI) combined with morphometry, and to investigate potential brain network alterations, following long-term seizure activity. Methods Repeated rs-fMRI measurements at 9.4 T between 3 and 8 months of age were combined with MEMRI at the final time point of the study. We used graph theory analysis to infer community structure and global and local network parameters from rs-fMRI data and compared them to brain region-wise manganese accumulation patterns and deformation-based morphometry (DBM). Results Functional connectivity (FC) was generally higher in GAERS when compared to NEC. Global network parameters and community structure were similar in NEC and GAERS, suggesting efficiently functioning networks in both strains. No progressive FC changes were observed in epileptic animals. Network-based statistics (NBS) revealed stronger FC within the cortical community, including regions of association and sensorimotor cortex, and with basal ganglia and limbic regions in GAERS, irrespective of age. Higher manganese accumulation in GAERS than in NEC was observed at 8 months of age, consistent with higher overall rs-FC, particularly in sensorimotor cortex and association cortex regions. Functional measures showed less similarity in subcortical regions. Whole brain volumes of 8 months-old GAERS were higher when compared to age-matched NEC, and DBM revealed increased volumes of several association and sensorimotor cortex regions and of the thalamus. Discussion rs-fMRI, MEMRI, and volumetric data collectively suggest the significance of cortical networks in GAERS, which correlates with an increased fronto-central connectivity in childhood absence epilepsy (CAE). Our findings also verify involvement of basal ganglia and limbic regions. Epilepsy-related network alterations are already present in juvenile animals. Consequently, this early condition seems to play a greater role in dynamic brain function than chronic absence seizures.
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Affiliation(s)
- Lydia Wachsmuth
- Clinic of Radiology, University of Münster, Münster, Germany
| | - Leo Hebbelmann
- Clinic of Radiology, University of Münster, Münster, Germany
| | - Jutta Prade
- Department of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Laura C. Kohnert
- Department of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | | | | | - Thomas Budde
- Institute of Physiology I, University of Münster, Münster, Germany
| | - Andreas Hess
- Department of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
- Department of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
- FAU NeW – Research Center for New Bioactive Compounds, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Cornelius Faber
- Clinic of Radiology, University of Münster, Münster, Germany
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Ma L, Liu G, Zhang P, Wang J, Huang W, Jiang Y, Zheng Y, Han N, Zhang Z, Zhang J. Altered Cerebro-Cerebellar Effective Connectivity in New-Onset Juvenile Myoclonic Epilepsy. Brain Sci 2022; 12:brainsci12121658. [PMID: 36552118 PMCID: PMC9775154 DOI: 10.3390/brainsci12121658] [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: 11/03/2022] [Revised: 11/27/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
(1) Objective: Resting-state fMRI studies have indicated that juvenile myoclonic epilepsy (JME) could cause widespread functional connectivity disruptions between the cerebrum and cerebellum. However, the directed influences or effective connectivities (ECs) between these brain regions are poorly understood. In the current study, we aimed to evaluate the ECs between the cerebrum and cerebellum in patients with new-onset JME. (2) Methods: Thirty-four new-onset JME patients and thirty-four age-, sex-, and education-matched healthy controls (HCs) were included in this study. We compared the degree centrality (DC) between the two groups to identify intergroup differences in whole-brain functional connectivity. Then, we used a Granger causality analysis (GCA) to explore JME-caused changes in EC between cerebrum regions and cerebellum regions. Furthermore, we applied a correlation analysis to identify associations between aberrant EC and disease severity in patients with JME. (3) Results: Compared to HCs, patients with JME showed significantly increased DC in the left cerebellum posterior lobe (CePL.L), the right inferior temporal gyrus (ITG.R) and the right superior frontal gyrus (SFG.R), and decreased DC in the left inferior frontal gyrus (IFG.L) and the left superior temporal gyrus (STG.L). The patients also showed unidirectionally increased ECs from cerebellum regions to the cerebrum regions, including from the CePL.L to the right precuneus (PreCU.R), from the left cerebellum anterior lobe (CeAL.L) to the ITG.R, from the right cerebellum posterior lobe (CePL.R) to the IFG.L, and from the left inferior semi-lunar lobule of the cerebellum (CeISL.L) to the SFG.R. Additionally, the EC from the CeISL.L to the SFG.R was negatively correlated with the disease severity. (4) Conclusions: JME patients showed unidirectional EC disruptions from the cerebellum to the cerebrum, and the negative correlation between EC and disease severity provides a new perspective for understanding the cerebro-cerebellar neural circuit mechanisms in JME.
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Affiliation(s)
- Laiyang Ma
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Guangyao Liu
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Pengfei Zhang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Jun Wang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Wenjing Huang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Yanli Jiang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Yu Zheng
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Na Han
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Second Clinical School, Lanzhou University, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
| | - Zhe Zhang
- School of Physics, Hangzhou Normal University, Hangzhou 311121, China
- Institute of Brain Science, Hangzhou Normal University, Hangzhou 311121, China
- Correspondence: (Z.Z.); (J.Z.); Tel.: +86-0571-28861955 (Z.Z.); +86-0931-8942090 (J.Z.)
| | - Jing Zhang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou 730030, China
- Gansu Province Clinical Research Center for Functional and Molecular Imaging, Lanzhou 730030, China
- Correspondence: (Z.Z.); (J.Z.); Tel.: +86-0571-28861955 (Z.Z.); +86-0931-8942090 (J.Z.)
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Garcia-Ramos C, Nair V, Maganti R, Mathis J, Conant LL, Prabhakaran V, Binder JR, Meyerand B, Hermann B, Struck AF. Network phenotypes and their clinical significance in temporal lobe epilepsy using machine learning applications to morphological and functional graph theory metrics. Sci Rep 2022; 12:14407. [PMID: 36002603 PMCID: PMC9402557 DOI: 10.1038/s41598-022-18495-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 08/12/2022] [Indexed: 02/08/2023] Open
Abstract
Machine learning analyses were performed on graph theory (GT) metrics extracted from brain functional and morphological data from temporal lobe epilepsy (TLE) patients in order to identify intrinsic network phenotypes and characterize their clinical significance. Participants were 97 TLE and 36 healthy controls from the Epilepsy Connectome Project. Each imaging modality (i.e., Resting-state functional Magnetic Resonance Imaging (RS-fMRI), and structural MRI) rendered 2 clusters: one comparable to controls and one deviating from controls. Participants were minimally overlapping across the identified clusters, suggesting that an abnormal functional GT phenotype did not necessarily mean an abnormal morphological GT phenotype for the same subject. Morphological clusters were associated with a significant difference in the estimated lifetime number of generalized tonic-clonic seizures and functional cluster membership was associated with age. Furthermore, controls exhibited significant correlations between functional GT metrics and cognition, while for TLE participants morphological GT metrics were linked to cognition, suggesting a dissociation between higher cognitive abilities and GT-derived network measures. Overall, these findings demonstrate the existence of clinically meaningful minimally overlapping phenotypes of morphological and functional GT networks. Functional network properties may underlie variance in cognition in healthy brains, but in the pathological state of epilepsy the cognitive limits might be primarily related to structural cerebral network properties.
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Affiliation(s)
- Camille Garcia-Ramos
- grid.14003.360000 0001 2167 3675Department of Medical Physics, University of Wisconsin-Madison, Madison, USA ,grid.14003.360000 0001 2167 3675Department of Neurology, University of Wisconsin-Madison, Madison, USA
| | - Veena Nair
- grid.14003.360000 0001 2167 3675Department of Radiology, University of Wisconsin-Madison, Madison, USA
| | - Rama Maganti
- grid.14003.360000 0001 2167 3675Department of Neurology, University of Wisconsin-Madison, Madison, USA
| | - Jedidiah Mathis
- grid.30760.320000 0001 2111 8460Department of Neurology, Medical College of Wisconsin, Milwaukee, USA
| | - Lisa L. Conant
- grid.14003.360000 0001 2167 3675Department of Neurology, University of Wisconsin-Madison, Madison, USA
| | - Vivek Prabhakaran
- grid.14003.360000 0001 2167 3675Department of Radiology, University of Wisconsin-Madison, Madison, USA
| | - Jeffrey R. Binder
- grid.30760.320000 0001 2111 8460Department of Neurology, Medical College of Wisconsin, Milwaukee, USA
| | - Beth Meyerand
- grid.14003.360000 0001 2167 3675Department of Medical Physics, University of Wisconsin-Madison, Madison, USA
| | - Bruce Hermann
- grid.14003.360000 0001 2167 3675Department of Neurology, University of Wisconsin-Madison, Madison, USA
| | - Aaron F. Struck
- grid.14003.360000 0001 2167 3675Department of Neurology, University of Wisconsin-Madison, Madison, USA ,grid.417123.20000 0004 0420 6882William S Middleton VA Hospital, Madison, WI USA
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Wang G, Wu W, Xu Y, Yang Z, Xiao B, Long L. Imaging Genetics in Epilepsy: Current Knowledge and New Perspectives. Front Mol Neurosci 2022; 15:891621. [PMID: 35706428 PMCID: PMC9189397 DOI: 10.3389/fnmol.2022.891621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/06/2022] [Indexed: 12/11/2022] Open
Abstract
Epilepsy is a neurological network disease with genetics playing a much greater role than was previously appreciated. Unfortunately, the relationship between genetic basis and imaging phenotype is by no means simple. Imaging genetics integrates multidimensional datasets within a unified framework, providing a unique opportunity to pursue a global vision for epilepsy. This review delineates the current knowledge of underlying genetic mechanisms for brain networks in different epilepsy syndromes, particularly from a neural developmental perspective. Further, endophenotypes and their potential value are discussed. Finally, we highlight current challenges and provide perspectives for the future development of imaging genetics in epilepsy.
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Affiliation(s)
- Ge Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Wenyue Wu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- Department of Neurology, The Second Affiliated Hospital of Nanchang University, Jiangxi, China
| | - Yuchen Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhuanyi Yang
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
- *Correspondence: Lili Long
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5
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Shakeshaft A, Panjwani N, Collingwood A, Crudgington H, Hall A, Andrade DM, Beier CP, Fong CY, Gardella E, Gesche J, Greenberg DA, Hamandi K, Koht J, Lim KS, Møller RS, Ng CC, Orsini A, Rees MI, Rubboli G, Selmer KK, Striano P, Syvertsen M, Thomas RH, Zarubova J, Richardson MP, Strug LJ, Pal DK. Sex-specific disease modifiers in juvenile myoclonic epilepsy. Sci Rep 2022; 12:2785. [PMID: 35190554 PMCID: PMC8861057 DOI: 10.1038/s41598-022-06324-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/25/2021] [Indexed: 11/22/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME) is a common idiopathic generalised epilepsy with variable seizure prognosis and sex differences in disease presentation. Here, we investigate the combined epidemiology of sex, seizure types and precipitants, and their influence on prognosis in JME, through cross-sectional data collected by The Biology of Juvenile Myoclonic Epilepsy (BIOJUME) consortium. 765 individuals met strict inclusion criteria for JME (female:male, 1.8:1). 59% of females and 50% of males reported triggered seizures, and in females only, this was associated with experiencing absence seizures (OR = 2.0, p < 0.001). Absence seizures significantly predicted drug resistance in both males (OR = 3.0, p = 0.001) and females (OR = 3.0, p < 0.001) in univariate analysis. In multivariable analysis in females, catamenial seizures (OR = 14.7, p = 0.001), absence seizures (OR = 6.0, p < 0.001) and stress-precipitated seizures (OR = 5.3, p = 0.02) were associated with drug resistance, while a photoparoxysmal response predicted seizure freedom (OR = 0.47, p = 0.03). Females with both absence seizures and stress-related precipitants constitute the prognostic subgroup in JME with the highest prevalence of drug resistance (49%) compared to females with neither (15%) and males (29%), highlighting the unmet need for effective, targeted interventions for this subgroup. We propose a new prognostic stratification for JME and suggest a role for circuit-based risk of seizure control as an avenue for further investigation.
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Affiliation(s)
- Amy Shakeshaft
- Department of Basic and Clinical Neurosciences, Maurice Wohl Clinical Neurosciences Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 5 Cutcombe Road, London, SE5 9RX, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Naim Panjwani
- Program in Genetics and Genome Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada
| | - Amber Collingwood
- Department of Basic and Clinical Neurosciences, Maurice Wohl Clinical Neurosciences Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 5 Cutcombe Road, London, SE5 9RX, UK
| | - Holly Crudgington
- Department of Basic and Clinical Neurosciences, Maurice Wohl Clinical Neurosciences Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 5 Cutcombe Road, London, SE5 9RX, UK
| | - Anna Hall
- Department of Basic and Clinical Neurosciences, Maurice Wohl Clinical Neurosciences Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 5 Cutcombe Road, London, SE5 9RX, UK
| | - Danielle M Andrade
- Adult Epilepsy Genetics Program, Krembil Research Institute, University of Toronto, Toronto, Canada
| | | | - Choong Yi Fong
- Division of Paediatric Neurology, Department of Paediatrics, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | | | | | | | - Jeanette Koht
- Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Kheng Seang Lim
- Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Rikke S Møller
- Danish Epilepsy Centre, Dianalund, Denmark
- Department of Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Ching Ching Ng
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Alessandro Orsini
- Department of Clinical and Experimental Medicine, Pisa University Hospital, Pisa, Italy
| | - Mark I Rees
- Neurology Research Group, Swansea University Medical School, Swansea, UK
| | - Guido Rubboli
- Danish Epilepsy Centre, Dianalund, Denmark
- University of Copenhagen, Copenhagen, Denmark
| | - Kaja K Selmer
- Division of Clinical Neuroscience, Department of Research and Innovation, Oslo University Hospital, Oslo, Norway
- National Centre for Epilepsy, Oslo University Hospital, Oslo, Norway
| | - Pasquale Striano
- IRCCS Istituto 'G. Gaslini', Genoa, Italy
- University of Genova, Genoa, Italy
| | - Marte Syvertsen
- Department of Neurology, Drammen Hospital, Vestre Viken Health Trust, Oslo, Norway
| | - Rhys H Thomas
- Newcastle Upon Tyne NHS Foundation Trust, Newcastle, UK
- Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle, UK
| | - Jana Zarubova
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Mark P Richardson
- Department of Basic and Clinical Neurosciences, Maurice Wohl Clinical Neurosciences Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 5 Cutcombe Road, London, SE5 9RX, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
- King's College Hospital, London, UK
| | - Lisa J Strug
- Program in Genetics and Genome Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada.
- Departments of Statistical Sciences and Computer Science and Division of Biostatistics, The University of Toronto, Toronto, Canada.
| | - Deb K Pal
- Department of Basic and Clinical Neurosciences, Maurice Wohl Clinical Neurosciences Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, 5 Cutcombe Road, London, SE5 9RX, UK.
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK.
- King's College Hospital, London, UK.
- Evelina London Children's Hospital, London, UK.
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Struck AF, Boly M, Hwang G, Nair V, Mathis J, Nencka A, Conant LL, DeYoe EA, Ragahavan M, Prabhakaran V, Binder JR, Meyerand ME, Hermann BP. Regional and global resting-state functional MR connectivity in temporal lobe epilepsy: Results from the Epilepsy Connectome Project. Epilepsy Behav 2021; 117:107841. [PMID: 33611101 PMCID: PMC8035304 DOI: 10.1016/j.yebeh.2021.107841] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/20/2021] [Accepted: 02/01/2021] [Indexed: 12/28/2022]
Abstract
Temporal lobe epilepsy (TLE) has been conceptualized as focal disease with a discrete neurobiological focus and can respond well to targeted resection or ablation. In contrast, the neuro-cognitive deficits resulting from TLE can be widespread involving regions beyond the primary epileptic network. We hypothesize that this seemingly paradoxical findings can be explained by differences in connectivity between the primary epileptic region which is hyper-connected and its secondary influence on global connectome organization. This hypothesis is tested using regional and global graph theory metrics where we anticipate that regional mesial-temporal hyperconnectivity will be found and correlate with seizure frequency while global networks will be disorganized and be more closely associated with neuro-cognitive deficits. Resting-state fMRI was used to examine temporal lobe regional connectivity and global functional connectivity from 102 patients with TLE and 55 controls. Connectivity matrices were calculated for subcortical volumes and cortical parcellations. Graph theory metrics (global clustering coefficient (GCC), degree, closeness) were compared between groups and in relation to neuropsychological profiles and disease covariates using permutation testing and causal analysis. In TLE there was a decrease in GCC (p = 0.0345) associated with a worse neuropsychological profile (p = 0.0134). There was increased connectivity in the left hippocampus/amygdala (degree p = 0.0103, closeness p = 0.0104) and a decrease in connectivity in the right lateral temporal lobe (degree p = 0.0186, closeness p = 0.0122). A ratio between the hippocampus/amygdala and lateral temporal lobe-temporal lobe connectivity ratio (TLCR) revealed differences between TLE and controls for closeness (left p = 0.00149, right p = 0.0494) and for degree on left p = 0.00169; with trend on right p = 0.0567. Causal analysis suggested that "Epilepsy Activity" (seizure frequency, anti-seizure medications) was associated with increase in TLCR but not in GCC, while cognitive decline was associated with decreased GCC. These findings support the hypothesis that in TLE there is hyperconnectivity in the hippocampus/amygdala and hypoconnectivity in the lateral temporal lobe associated with "Epilepsy Activity." While, global connectome disorganization was associated with worse neuropsychological phenotype.
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Affiliation(s)
- Aaron F Struck
- University of Wisconsin-Madison, Department of Neurology, United States; William S. Middleton Veterans Administration Hospital, Madison, WI, United States.
| | - Melanie Boly
- University of Wisconsin-Madison, Department of Neurology
| | - Gyujoon Hwang
- University of Wisconsin-Madison, Department of Medical Physics
| | - Veena Nair
- University of Wisconsin-Madison, Department of Radiology
| | | | - Andrew Nencka
- Medical College of Wisconsin, Department of Radiology
| | - Lisa L Conant
- Medical College of Wisconsin, Department of Neurology
| | - Edgar A DeYoe
- Medical College of Wisconsin, Department of Radiology
| | | | | | | | - Mary E Meyerand
- University of Wisconsin-Madison, Department of Medical Physics
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Can we predict drug response by functional connectivity in patients with juvenile myoclonic epilepsy? Clin Neurol Neurosurg 2020; 198:106119. [PMID: 32763668 DOI: 10.1016/j.clineuro.2020.106119] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 11/22/2022]
Abstract
OBJECTIVES We investigated functional connectivity based on EEG using graph theoretical analysis in patients with newly diagnosed juvenile myoclonic epilepsy (JME), and whether it could play a role as a biomarker predicting antiepileptic drug (AED) response. METHODS We consecutively enrolled 38 patients with JME and 40 normal controls. The initial EEG was undertaken at the time of diagnosis of JME in a drug-naïve state. The second EEG was done after at least 12 months from the time of the initial EEG. We classified the patients with JME into two groups according to AED response at the time of taking the second EEG. We investigated functional connectivity based on graph theoretical analysis using connectivity measures of the coherence and phase locking value. RESULTS In the analysis of functional connectivity using coherence as a connectivity measure, the global efficiency and local efficiency in the AED poor responders (N = 4) decreased, whereas the small-worldness index increased. In the analysis of functional connectivity using phase locking value as a connectivity measure, the global efficiency and local efficiency in the AED poor responders decreased. However, in the AED good responders (N = 34), none of the network measures were different from those in healthy controls. CONCLUSIONS We newly found that there were significant differences of functional connectivity based on initial EEG according to AED response in the patients with JME. This suggests that brain connectivity could play a role as a new biomarker predicting AED response in patients with JME.
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Sarnat HB. Proteoglycan (Keratan Sulfate) Barrier in Developing Human Forebrain Isolates Cortical Epileptic Networks From Deep Heterotopia, Insulates Axonal Fascicles, and Explains Why Axosomatic Synapses Are Inhibitory. J Neuropathol Exp Neurol 2020; 78:1147-1159. [PMID: 31633782 DOI: 10.1093/jnen/nlz096] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Axons from deep heterotopia do not extend through U-fibers, except transmantle dysplasias. Keratan sulfate (KS) in fetal spinal cord/brainstem median septum selectively repels glutamatergic axons while enabling GABAergic commissural axons. Immunocytochemical demonstration of KS in neocortical resections and forebrain at autopsy was studied in 12 fetuses and neonates 9-41 weeks gestational age (GA), 9 infants, children, and adolescents and 5 patients with focal cortical dysplasias (FCD1a). From 9 to 15 weeks GA, no KS is seen in the cortical plate; 19-week GA reactivity is detected in the molecular zone. By 28 weeks GA, patchy granulofilamentous reactivity appears in extracellular matrix and adheres to neuronal somata with increasing intensity in deep cortex and U-fibers at term. Perifascicular KS surrounds axonal bundles of both limbs of the internal capsule and within basal ganglia from 9 weeks GA. Thalamus and globus pallidus exhibit intense astrocytic reactivity from 9 weeks GA. In FCD1a, U-fiber reactivity is normal, discontinuous or radial. Ultrastructural correlates were not demonstrated; KS is not electron-dense. Proteoglycan barrier of the U-fiber layer impedes participation of deep heterotopia in cortical epileptic networks. Perifascicular KS prevents aberrant axonal exit from or entry into long and short tracts. KS adhesion to neuronal somatic membranes may explain inhibitory axosomatic synapses.
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Affiliation(s)
- Harvey B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology), and Clinical Neurosciences, University of Calgary, Cumming School of Medicine; and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, Alberta, Canada
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Li Y, Wang Y, Wang Y, Wang H, Li D, Chen Q, Huang W. Impaired Topological Properties of Gray Matter Structural Covariance Network in Epilepsy Children With Generalized Tonic-Clonic Seizures: A Graph Theoretical Analysis. Front Neurol 2020; 11:253. [PMID: 32373045 PMCID: PMC7176815 DOI: 10.3389/fneur.2020.00253] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/17/2020] [Indexed: 12/30/2022] Open
Abstract
Modern network science has provided exciting new opportunities for understanding the human brain as a complex network of interacting regions. The improved knowledge of human brain network architecture has made it possible for clinicians to detect the network changes in neurological diseases. Generalized tonic–clonic seizure (GTCS) is a subtype of epilepsy characterized by generalized spike-wave discharge involving the bilateral hemispheres during seizure. Network researches in adults with GTCS exhibited that GTCS can be conceptualized as a network disorder. However, the overall organization of the brain structural covariance network in children with GTCS remains largely unclear. Here, we used a graph theory method to assess the gray matter structural covariance network organization of 14 pediatric patients diagnosed with GTCS and 29 healthy control children. The group differences in regional and global topological properties were investigated. Results revealed significant changes in nodal betweenness locating in brain regions known to be abnormal in GTCS (the right thalamus, bilateral temporal pole, and some regions of default mode network). The network hub analysis results were in accordance with the regional betweenness, which presented a disrupted regional topology of structural covariance network in children with GTCS. To our knowledge, the present study is the first work reporting the changes of structural topological properties in children with GTCS. The findings contribute new insights into the understanding of the neural mechanisms underlying GTCS and highlight critical regions for future neuroimaging research in children with GTCS.
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Affiliation(s)
- Yongxin Li
- Formula-Pattern Research Center, School of Traditional Chinese Medicine, Jinan University, Guangzhou, China
| | - Ya Wang
- Guangdong Provincial Key Laboratory of Medical Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yanfang Wang
- Guangdong Provincial Key Laboratory of Medical Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Huirong Wang
- Electromechanic Engineering College, Guangdong Engineering Polytechnic, Guangzhou, China
| | - Ding Li
- Guangdong Provincial Key Laboratory of Medical Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Qian Chen
- Department of Pediatric Neurosurgery, Shenzhen Children's Hospital, Shenzhen, China
| | - Wenhua Huang
- Guangdong Provincial Key Laboratory of Medical Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
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Lee H, Seo SA, Lee BI, Kim SE, Park KM. Thalamic nuclei volumes and network in juvenile myoclonic epilepsy. Acta Neurol Scand 2020; 141:271-278. [PMID: 31745976 DOI: 10.1111/ane.13198] [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: 07/31/2019] [Revised: 10/13/2019] [Accepted: 11/15/2019] [Indexed: 01/02/2023]
Abstract
OBJECTIVE The aim of this study was to investigate the alterations of thalamic nuclei volumes and intrinsic thalamic networks in patients with juvenile myoclonic epilepsy (JME) compared to healthy controls. METHODS We enrolled 50 patients with JME and 42 healthy controls. We obtained structural volumes of the individual thalamic nuclei based on T1-weighted imaging and performed intrinsic thalamic network analysis using graph theoretical analysis. We analyzed the differences of thalamic nuclei volumes and intrinsic thalamic networks between the patients with JME and healthy controls. RESULTS In the patients with JME, there were significant alterations of thalamic nuclei volumes compared to healthy controls. Right laterodorsal and left suprageniculate nuclei volumes were significantly increased (0.0019% vs 0.0014%, P < .0001; 0.0011% vs 0.0008%, P = .0006, respectively), whereas left ventral posterolateral, left ventromedial, and left pulvinar inferior nuclei volumes (0.0572% vs 0.0664%, P = .0001; 0.0013% vs 0.0015%, P = .0002; 0.0120% vs 0.0140%, P < .0001, respectively) were decreased in the patients with JME. Furthermore, the intrinsic thalamic network of the patients with JME was significantly different from that of the healthy controls. The modularity in the patients with JME was significantly increased over that in healthy controls (0.0785 vs 0.0212, P = .039). CONCLUSION We found that there were significant alterations of thalamic nuclei volumes and intrinsic thalamic networks in patients with JME compared to healthy controls. These findings might contribute to the underlying pathogenesis of in JME.
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Affiliation(s)
- Ho‐Joon Lee
- Department of Radiology Haeundae Paik Hospital Inje University College of Medicine Busan Korea
| | - Sol A. Seo
- Department of Biomedical Engineering Inje University Gimhae Korea
| | - Byung In Lee
- Department of Neurology Haeundae Paik Hospital Inje University College of Medicine Busan Korea
| | - Sung Eun Kim
- Department of Neurology Haeundae Paik Hospital Inje University College of Medicine Busan Korea
| | - Kang Min Park
- Department of Neurology Haeundae Paik Hospital Inje University College of Medicine Busan Korea
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Gilsoul M, Grisar T, Delgado-Escueta AV, de Nijs L, Lakaye B. Subtle Brain Developmental Abnormalities in the Pathogenesis of Juvenile Myoclonic Epilepsy. Front Cell Neurosci 2019; 13:433. [PMID: 31611775 PMCID: PMC6776584 DOI: 10.3389/fncel.2019.00433] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/09/2019] [Indexed: 12/17/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME), a lifelong disorder that starts during adolescence, is the most common of genetic generalized epilepsy syndromes. JME is characterized by awakening myoclonic jerks and myoclonic-tonic-clonic (m-t-c) grand mal convulsions. Unfortunately, one third of JME patients have drug refractory m-t-c convulsions and these recur in 70-80% who attempt to stop antiepileptic drugs (AEDs). Behavioral studies documented impulsivity, but also impairment of executive functions relying on organization and feedback, which points to prefrontal lobe dysfunction. Quantitative voxel-based morphometry (VBM) revealed abnormalities of gray matter (GM) volumes in cortical (frontal and parietal) and subcortical structures (thalamus, putamen, and hippocampus). Proton magnetic resonance spectroscopy (MRS) found evidence of dysfunction of thalamic neurons. White matter (WM) integrity was disrupted in corpus callosum and frontal WM tracts. Magnetic resonance imaging (MRI) further unveiled anomalies in both GM and WM structures that were already present at the time of seizure onset. Aberrant growth trajectories of brain development occurred during the first 2 years of JME diagnosis. Because of genetic origin, disease causing variants were sought, first by positional cloning, and most recently, by next generation sequencing. To date, only six genes harboring pathogenic variants (GABRA1, GABRD, EFHC1, BRD2, CASR, and ICK) with Mendelian and complex inheritance and covering a limited proportion of the world population, are considered as major susceptibility alleles for JME. Evidence on the cellular role, developmental and cell-type expression profiles of these six diverse JME genes, point to their pathogenic variants driving the first steps of brain development when cell division, expansion, axial, and tangential migration of progenitor cells (including interneuron cortical progenitors) sculpture subtle alterations in brain networks and microcircuits during development. These alterations may explain "microdysgenesis" neuropathology, impulsivity, executive dysfunctions, EEG polyspike waves, and awakening m-t-c convulsions observed in JME patients.
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Affiliation(s)
- Maxime Gilsoul
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Thierry Grisar
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Antonio V. Delgado-Escueta
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Epilepsy Genetics/Genomics Lab, Neurology and Research Services, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Laurence de Nijs
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- School for Mental Health and Neuroscience, Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, Netherlands
| | - Bernard Lakaye
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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Garcia-Ramos C, Dabbs K, Lin JJ, Jones JE, Stafstrom CE, Hsu DA, Meyerand ME, Prabhakaran V, Hermann BP. Network analysis of prospective brain development in youth with benign epilepsy with centrotemporal spikes and its relationship to cognition. Epilepsia 2019; 60:1838-1848. [PMID: 31347155 PMCID: PMC7394051 DOI: 10.1111/epi.16290] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/25/2019] [Accepted: 06/25/2019] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Benign epilepsy with centrotemporal spikes (BECTS) is the most common childhood idiopathic localization-related epilepsy syndrome. BECTS presents normal routine magnetic resonance imaging (MRI); however, quantitative analytic techniques have captured subtle cortical and subcortical magnetic resonance anomalies. Network science, including graph theory (GT) analyses, facilitates understanding of brain covariance patterns, potentially informing in important ways how this common self-limiting epilepsy syndrome may impact normal patterns of brain and cognitive development. METHODS GT analyses examined the developmental covariance among cortical and subcortical regions in children with new/recent onset BECTS (n = 19) and typically developing healthy controls (n = 22) who underwent high-resolution MRI and cognitive assessment at baseline and 2 years later. Global (transitivity, global efficiency, and modularity index [Q]) and regional measures (local efficiency and hubs) were investigated to characterize network development in each group. Associations between baseline-based GT measures and cognition at both time points addressed the implications of GT analyses for cognition and prospective cognitive development. Furthermore, an individual contribution measure was investigated, reflecting how important for cognition it is for BECTS to resemble the correlation matrices of controls. RESULTS Groups exhibited similar Q and overall network configuration, with BECTS presenting significantly higher transitivity and both global and local efficiency. Furthermore, both groups presented a similar number of hubs, with BECTS showing a higher number in temporal lobe regions compared to controls. The investigated measures were negatively associated with 2-year cognitive outcomes in BECTS. SIGNIFICANCE Children with BECTS present a higher-than-normal global developmental configuration compared to controls, along with divergence from normality in terms of regional configuration. Baseline GT measures demonstrate potential as a cognitive biomarker to predict cognitive outcome in BECTS 2 years after diagnosis. Similarities and differences in developmental network configurations and their implications for cognition and behavior across common epilepsy syndromes are of theoretical interest and clinical relevance.
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Affiliation(s)
- Camille Garcia-Ramos
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Kevin Dabbs
- Department of Neurology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Jack J Lin
- Department of Neurology, University of California, Irvine, Irvine, California
| | - Jana E Jones
- Department of Neurology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Carl E Stafstrom
- Department of Neurology, Johns Hopkins Medical School, Baltimore, Maryland
| | - David A Hsu
- Department of Neurology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Mary Elizabeth Meyerand
- Department of Biomedical Engineering, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Vivek Prabhakaran
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin.,Department of Radiology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - Bruce P Hermann
- Department of Neurology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
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Lee H, Park KM. Structural and functional connectivity in newly diagnosed juvenile myoclonic epilepsy. Acta Neurol Scand 2019; 139:469-475. [PMID: 30758836 DOI: 10.1111/ane.13079] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 02/10/2019] [Indexed: 01/02/2023]
Abstract
OBJECTIVES We aimed to evaluate structural and functional connectivity of patients with newly diagnosed juvenile myoclonic epilepsy (JME) compared to healthy subjects. METHODS We enrolled 36 patients with a diagnosis of JME, who were newly diagnosed and drug-naïve. They underwent T1-weighted imaging, and structural volumes were calculated using FreeSurfer software. In addition, EEG data were obtained from all of them. Structural and functional connectivity matrices were estimated by calculating the structural volumes and EEG amplitude correlation, respectively. Then, the connectivity measures were calculated using the BRAPH program. We also enrolled healthy subjects to compare its structural and functional connectivity with the patients with JME. RESULTS We observed that patients with JME exhibited significantly different functional and structural connectivity compared to healthy control subjects. In the global structural connectivity, global efficiency, and local efficiency, and small-worldness index were decreased, whereas characteristic path length was increased in patients with JME. Betweenness centrality of cingulate, precentral, superior parietal, and superior frontal cortex was increased in patients with JME whereas that of hippocampus was decreased. In the functional connectivity, the betweenness centrality of the fronto-central electrodes was significantly increased. CONCLUSIONS This study reports that the structural connectivity and functional connectivity in patients with JME are significantly different from those in healthy control subjects, even those with newly diagnosed drug-naive state. The patients with JME exhibited disrupted topological disorganization of the global brain network and hub reorganization in structural and functional connectivity. These alterations are implicated in the pathogenesis of JME and suggestive of network disease.
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Affiliation(s)
- Ho‐Joon Lee
- Department of Radiology Haeundae Paik Hospital Busan Korea
| | - Kang Min Park
- Department of Neurology Haeundae Paik Hospital Busan Korea
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