1
|
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.
Collapse
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
| |
Collapse
|
2
|
Plutino S, Laghouati E, Jarre G, Depaulis A, Guillemain I, Bureau I. Barrel cortex development lacks a key stage of hyperconnectivity from deep to superficial layers in a rat model of Absence Epilepsy. Prog Neurobiol 2024; 234:102564. [PMID: 38244975 DOI: 10.1016/j.pneurobio.2023.102564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 12/04/2023] [Accepted: 12/30/2023] [Indexed: 01/22/2024]
Abstract
During development of the sensory cortex, the ascending innervation from deep to upper layers provides a temporary scaffold for the construction of other circuits that remain at adulthood. Whether an alteration in this sequence leads to brain dysfunction in neuro-developmental diseases remains unknown. Using functional approaches in a genetic model of Absence Epilepsy (GAERS), we investigated in barrel cortex, the site of seizure initiation, the maturation of excitatory and inhibitory innervations onto layer 2/3 pyramidal neurons and cell organization into neuronal assemblies. We found that cortical development in GAERS lacks the early surge of connections originating from deep layers observed at the end of the second postnatal week in normal rats and the concomitant structuring into multiple assemblies. Later on, at seizure onset (1 month old), excitatory neurons are hyper-excitable in GAERS when compared to Wistar rats. These findings suggest that early defects in the development of connectivity could promote this typical epileptic feature and/or its comorbidities.
Collapse
Affiliation(s)
| | - Emel Laghouati
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | - Guillaume Jarre
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | - Antoine Depaulis
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | - Isabelle Guillemain
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | | |
Collapse
|
3
|
Dreier JW, Trabjerg BB, Plana-Ripoll O, Skipper N, Agerbo E, Cotsapas C, Berg AT, Christensen J. Epilepsy in childhood and school performance: a nation-wide cohort study. Brain 2024; 147:532-541. [PMID: 38102964 DOI: 10.1093/brain/awad382] [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: 08/15/2023] [Accepted: 10/26/2023] [Indexed: 12/17/2023] Open
Abstract
Childhood epilepsy has been linked to poor academic performance, but large-scale studies are lacking. In this nation-wide study of school-aged children, we examined the association between childhood epilepsy and school performance in standardized tests according to phenotypic and treatment-related characteristics. We performed a matched register-based cohort study of children born in Denmark (1997-2009) who participated in the Danish National School Test Programme between 2010 and 2019. We used population and health registers to identify children with epilepsy and a randomly sampled sex- and age-matched reference cohort without epilepsy (ratio 1:10). Norm-based test scores from language and mathematics reflecting performance as a percentile of the nation-wide distribution of scores (scale 1-100) were used to assess academic performance. Adjusted differences in mean standardized scores between children with and without epilepsy were estimated using linear regression models. Among 582 840 children participating in the School Test Programme, we identified 4659 (0.8%) children with epilepsy (52.8% males) and 46 590 matched reference children. Median age at epilepsy onset was 7.5 years (interquartile range: 4.0-10.6). Childhood epilepsy was associated with poorer school performance overall (mean score = 48.2 versus references = 56.7; adjusted difference = -6.7, 95% CI: -7.4 to -6.0), and worse performance was found in all epilepsy subgroups, including in 3534 children with uncomplicated epilepsy (i.e. no other pre-existing neurologic or intellectual disabilities and no identified possible cause for epilepsy; adjusted difference = -6.0, 95% CI: -6.8 to -5.2). No major variation by sex, age or subject was observed, but larger score differences were seen in children using antiseizure medication at time of testing (e.g. valproate monotherapy, adjusted difference = -9.3, 95% CI: -11.5 to -7.0 and lamotrigine monotherapy, adjusted difference = -13.1, 95% CI: -15.0 to -11.3) and in children with psychiatric comorbidity, especially epilepsy with comorbid intellectual disability (adjusted difference = -27.0, 95% CI: -30.0 to -23.9) and epilepsy with comorbid attention deficit/hyperactivity disorder (adjusted difference = -15.7, 95% CI: -19.0 to -12.4). Children with epilepsy scored significantly lower than their unaffected siblings (adjusted difference = -6.2, 95% CI: -7.1 to -5.4). In conclusion, childhood epilepsy was associated with impaired academic performance throughout schooling, which suggest that there is a widespread need for educational support of children with epilepsy, even when the child has no other comorbidities and when the epilepsy appears well-managed.
Collapse
Affiliation(s)
- Julie W Dreier
- National Centre for Register-Based Research, Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
- Centre for Integrated Register-based Research (CIRRAU), Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
- Department of Clinical Medicine, University of Bergen, 5021 Bergen, Norway
| | - Betina B Trabjerg
- National Centre for Register-Based Research, Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
- Centre for Integrated Register-based Research (CIRRAU), Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
| | - Oleguer Plana-Ripoll
- National Centre for Register-Based Research, Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
- Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Niels Skipper
- Department of Economics and Business Economics, Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
| | - Esben Agerbo
- National Centre for Register-Based Research, Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
- Centre for Integrated Register-based Research (CIRRAU), Business and Social Sciences, Aarhus University, 8210 Aarhus V, Denmark
| | - Chris Cotsapas
- Department of Neurology, Yale, New Haven, CT 06510, USA
- Department of Genetics, Yale, New Haven, CT 06510, USA
| | - Anne T Berg
- Department of Neurology, Northwestern University - Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jakob Christensen
- Department of Neurology, Affiliated Member of the European Reference Network EpiCARE, Aarhus University Hospital, 8200 Aarhus N, Denmark
- Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark
| |
Collapse
|
4
|
Ding Y, Guo K, Li J, Shan Q, Guo Y, Chen M, Wu Y, Wang X. Alterations in brain network functional connectivity and topological properties in DRE patients. Front Neurol 2023; 14:1238421. [PMID: 38116109 PMCID: PMC10729765 DOI: 10.3389/fneur.2023.1238421] [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: 06/11/2023] [Accepted: 10/20/2023] [Indexed: 12/21/2023] Open
Abstract
Objective The study aimed to find the difference in functional network topology on interictal electroencephalographic (EEG) between patients with drug-resistant epilepsy (DRE) and healthy people. Methods We retrospectively analyzed the medical records as well as EEG data of ten patients with DRE and recruited five sex-age-matched healthy controls (HC group). Each participant remained awake while undergoing video-electroencephalography (vEEG) monitoring. After excluding data that contained abnormal discharges, we screened EEG segments that were free of artifacts and put them together into 20-min segments. The screened data was bandpass filtered to different frequency bands (delta, theta, alpha, beta, and gamma). The weighted phase lag index (wPLI) and the network properties were calculated to evaluate changes in the topology of the functional network. Finally, the results were statistically analyzed, and the false discovery rate (FDR) was used to correct for differences after multiple comparisons. Results In the full frequency band (0.5-45 Hz), the functional connectivity in the DRE group during the interictal period was significantly lower than that in the HC group (p < 0.05). Compared to the HC group, in the full frequency band, the DRE group exhibited significantly decreased clustering coefficient (CC), node degree (D), and global efficiency (GE), while the characteristic path length (CPL) significantly increased (p < 0.05). In the sub-frequency bands, the functional connectivity of the DRE group was significantly lower than that of the HC group in the delta band but higher in the alpha, beta, and gamma bands (p < 0.05). The statistical results of network properties revealed that in the delta band, the DRE group had significantly decreased values for D, CC, and GE, but in the alpha, beta, and gamma bands, these values were significantly increased (p < 0.05). Additionally, the CPL of the DRE group significantly increased in the delta and theta bands but significantly decreased in the alpha, beta, and gamma bands (p < 0.05). Conclusion The topology structure of the functional network in DRE patients was significantly changed compared with healthy people, which was reflected in different frequency bands. It provided a theoretical basis for understanding the pathological network alterations of DRE.
Collapse
Affiliation(s)
- Yongqiang Ding
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Kunlin Guo
- Henan Key Laboratory of Brain Science and Brain–Computer Interface Technology, School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou, China
| | - Jialiang Li
- Department of Neurosurgery, The First People Hospital of Shangqiu, Shangqiu, China
| | - Qiao Shan
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yongkun Guo
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Mingming Chen
- Henan Key Laboratory of Brain Science and Brain–Computer Interface Technology, School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou, China
| | - Yuehui Wu
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xinjun Wang
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| |
Collapse
|
5
|
Zhang T, Zhang Y, Ren J, Zhou H, Yang M, Li L, Lei D, Gong Q, Zhou D, Yang T. Dynamic alterations of striatal-related functional networks in juvenile absence epilepsy. Epilepsy Behav 2023; 149:109506. [PMID: 37925871 DOI: 10.1016/j.yebeh.2023.109506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/18/2023] [Accepted: 10/20/2023] [Indexed: 11/07/2023]
Abstract
PURPOSE To explore the features of dynamic functional connectivity (dFC) variability of striatal-cortical/subcortical networks in juvenile absence epilepsy (JAE). METHODS We collected resting-state functional magnetic imaging data from 18 JAE patients and 28 healthy controls. The striatum was divided into six pairs of regions: the inferior-ventral striatum (VSi), superior-ventral striatum (VSs), dorsal-caudal putamen, dorsal-rostral putamen, dorsal-caudate (DC) and ventral-rostral putamen. We assessed the dFC variability of each subdivision in the whole brain using the sliding-window method, and correlated altered circuit with clinical variables in JAE patients. RESULTS We found altered dFC variability of striatal-cortical/subcortical networks in patients with JAE. The VSs exhibited decreased dFC variability with subcortical regions, and dFC variability between VSs and thalamus was negatively correlated with epilepsy duration. For the striatal-cortical networks, the dFC variability was decreased in VSi-affective network but increased in DC-executive network. The altered dynamics of striatal-cortical networks involved crucial nodes of the default mode network (DMN). CONCLUSION JAE patients exhibit excessive stability in the striatal-subcortical networks. For striatal-cortical networks in JAE, the striatal-affective circuit was more stable, while the striatal-executive circuit was more variable. Furthermore, crucial nodes of DMN were changed in striatal-cortical networks in JAE.
Collapse
Affiliation(s)
- Tianyu Zhang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yingying Zhang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jiechuan Ren
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Huanyu Zhou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Menghan Yang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Lei Li
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Du Lei
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Qiyong Gong
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Dong Zhou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Tianhua Yang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| |
Collapse
|
6
|
Medvedeva TM, Sysoeva MV, Sysoev IV, Vinogradova LV. Intracortical functional connectivity dynamics induced by reflex seizures. Exp Neurol 2023; 368:114480. [PMID: 37454711 DOI: 10.1016/j.expneurol.2023.114480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 06/13/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023]
Abstract
Functional connectivity analysis is gaining more interest due to its promising clinical applications. To study network mechanisms underlying seizure termination and postictal depression, we explore dynamics of interhemispheric functional connectivity near the offset of focal and bilateral seizures in the experimental model of reflex audiogenic epilepsy. In the model, seizures and spreading depression are induced by sound stimulation of genetically predisposed rodents. We characterize temporal evolution of seizure-associated coupling dynamics in the frontoparietal cortex during late ictal, immediate postictal and interictal resting states, using two measures applied to local field potentials recorded in awake epileptic rats. Signals were analyzed with mean phase coherence index in delta (1-4 Hz), theta (4-10 Hz) beta (10-25 Hz) and gamma (25-50 Hz) frequency bands and mutual information function. The study shows that reflex seizures elicit highly dynamic changes in interhemispheric functional coupling with seizure-, region- and frequency-specific patterns of increased and decreased connectivity during late ictal and immediate postictal periods. Also, secondary generalization of recurrent seizures (kindling) is associated with pronounced alterations in resting-state functional connectivity - an early wideband decrease and a subsequent beta-gamma increase. The findings show that intracortical functional connectivity is dynamically modified in response to seizures on short and long timescales, suggesting the existence of activity-dependent plastic network alterations that may promote or prevent seizure propagation within the cortex and underlie postictal behavioral impairments.
Collapse
Affiliation(s)
- Tatiana M Medvedeva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - Marina V Sysoeva
- Yuri Gagarin State Technical University of Saratov, Saratov, Russia
| | - Ilya V Sysoev
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia; Saratov State University, Saratov, Russia
| | - Lyudmila V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
| |
Collapse
|
7
|
Can Presurgical Interhemispheric EEG Connectivity Predict Outcome in Hemispheric Surgery? A Brain Machine Learning Approach. Brain Sci 2022; 13:brainsci13010071. [PMID: 36672052 PMCID: PMC9856795 DOI: 10.3390/brainsci13010071] [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: 11/25/2022] [Revised: 12/21/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVES Hemispherotomy (HT) is a surgical option for treatment of drug-resistant seizures due to hemispheric structural lesions. Factors affecting seizure outcome have not been fully clarified. In our study, we used a brain Machine Learning (ML) approach to evaluate the possible role of Inter-hemispheric EEG Connectivity (IC) in predicting post-surgical seizure outcome. METHODS We collected 21 pediatric patients with drug-resistant epilepsy; who underwent HT in our center from 2009 to 2020; with a follow-up of at least two years. We selected 5-s windows of wakefulness and sleep pre-surgical EEG and we trained Artificial Neuronal Network (ANN) to estimate epilepsy outcome. We extracted EEG features as input data and selected the ANN with best accuracy. RESULTS Among 21 patients, 15 (71%) were seizure and drug-free at last follow-up. ANN showed 73.3% of accuracy, with 85% of seizure free and 40% of non-seizure free patients appropriately classified. CONCLUSIONS The accuracy level that we reached supports the hypothesis that pre-surgical EEG features may have the potential to predict epilepsy outcome after HT. SIGNIFICANCE The role of pre-surgical EEG data in influencing seizure outcome after HT is still debated. We proposed a computational predictive model, with an ML approach, with a high accuracy level.
Collapse
|
8
|
Sarkisova K, van Luijtelaar G. The impact of early-life environment on absence epilepsy and neuropsychiatric comorbidities. IBRO Neurosci Rep 2022; 13:436-468. [PMID: 36386598 PMCID: PMC9649966 DOI: 10.1016/j.ibneur.2022.10.012] [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: 09/30/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 11/11/2022] Open
Abstract
This review discusses the long-term effects of early-life environment on epileptogenesis, epilepsy, and neuropsychiatric comorbidities with an emphasis on the absence epilepsy. The WAG/Rij rat strain is a well-validated genetic model of absence epilepsy with mild depression-like (dysthymia) comorbidity. Although pathologic phenotype in WAG/Rij rats is genetically determined, convincing evidence presented in this review suggests that the absence epilepsy and depression-like comorbidity in WAG/Rij rats may be governed by early-life events, such as prenatal drug exposure, early-life stress, neonatal maternal separation, neonatal handling, maternal care, environmental enrichment, neonatal sensory impairments, neonatal tactile stimulation, and maternal diet. The data, as presented here, indicate that some early environmental events can promote and accelerate the development of absence seizures and their neuropsychiatric comorbidities, while others may exert anti-epileptogenic and disease-modifying effects. The early environment can lead to phenotypic alterations in offspring due to epigenetic modifications of gene expression, which may have maladaptive consequences or represent a therapeutic value. Targeting DNA methylation with a maternal methyl-enriched diet during the perinatal period appears to be a new preventive epigenetic anti-absence therapy. A number of caveats related to the maternal methyl-enriched diet and prospects for future research are discussed.
Collapse
Affiliation(s)
- Karine Sarkisova
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Butlerova str. 5a, Moscow 117485, Russia
| | - Gilles van Luijtelaar
- Donders Institute for Brain, Cognition, and Behavior, Donders Center for Cognition, Radboud University, Nijmegen, PO Box 9104, 6500 HE Nijmegen, the Netherlands
| |
Collapse
|
9
|
Tran DK, Poliakov AV, Friedman SD, Goldstein HE, Shurtleff HA, Bowen K, Patrick KE, Warner M, Novotny EJ, Ojemann JG, Hauptman JS. Concordance of functional MRI memory task and resting-state functional MRI connectivity used in surgical planning for pediatric temporal lobe epilepsy. J Neurosurg Pediatr 2022; 30:394-399. [PMID: 35907201 DOI: 10.3171/2022.6.peds221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/15/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Assessing memory is often critical in surgical evaluation, although difficult to assess in young children and in patients with variable task abilities. While obtaining interpretable data from task-based functional MRI (fMRI) measures is common in compliant and awake patients, it is not known whether functional connectivity MRI (fcMRI) data show equivalent results. If this were the case, it would have substantial clinical and research generalizability. To evaluate this possibility, the authors evaluated the concordance between fMRI and fcMRI data collected in a presurgical epilepsy cohort. METHODS Task-based fMRI data for autobiographical memory tasks and resting-state fcMRI data were collected in patients with epilepsy evaluated at Seattle Children's Hospital between 2010 and 2017. To assess memory-related activation and laterality, signal change in task-based measures was computed as a percentage of the average blood oxygen level-dependent signal over the defined regions of interest. An fcMRI data analysis was performed using 1000 Functional Connectomes Project scripts based on Analysis of Functional NeuroImages and FSL (Functional Magnetic Resonance Imaging of the Brain Software Library) software packages. Lateralization indices (LIs) were estimated for activation and connectivity measures. The concordance between these two measures was evaluated using correlation and regression analysis. RESULTS In this epilepsy cohort studied, the authors observed concordance between fMRI activation and fcMRI connectivity, with an LI regression coefficient of 0.470 (R2 = 0.221, p = 0.00076). CONCLUSIONS Previously published studies have demonstrated fMRI and fcMRI overlap between measures of vision, attention, and language. In the authors' clinical sample, task-based measures of memory and analogous resting-state mapping were similarly linked in pattern and strength. These results support the use of fcMRI methods as a proxy for task-based memory performance in presurgical patients, perhaps including those who are more limited in their behavioral compliance. Future investigations to extend these results will be helpful to explore how the magnitudes of effect are associated with neuropsychological performance and postsurgical behavioral changes.
Collapse
Affiliation(s)
- Diem Kieu Tran
- 1Department of Neurological Surgery, University of Washington, Seattle
- 2Division of Neurosurgery, Seattle Children's Hospital, Seattle
| | - Andrew V Poliakov
- 2Division of Neurosurgery, Seattle Children's Hospital, Seattle
- 3Department of Radiology, Seattle Children's Hospital, Seattle
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
| | - Seth D Friedman
- 3Department of Radiology, Seattle Children's Hospital, Seattle
| | - Hannah E Goldstein
- 1Department of Neurological Surgery, University of Washington, Seattle
- 2Division of Neurosurgery, Seattle Children's Hospital, Seattle
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
| | - Hillary A Shurtleff
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
- 5Center for Integrated Brain Research, Seattle Children's Hospital, Seattle
- 6Division of Pediatric Neurology, Seattle Children's Hospital, Seattle; and
| | - Katherine Bowen
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
- 6Division of Pediatric Neurology, Seattle Children's Hospital, Seattle; and
| | - Kristina E Patrick
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
- 6Division of Pediatric Neurology, Seattle Children's Hospital, Seattle; and
- 7Department of Neurology, University of Washington, Seattle, Washington
| | - Molly Warner
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
| | - Edward J Novotny
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
- 6Division of Pediatric Neurology, Seattle Children's Hospital, Seattle; and
- 7Department of Neurology, University of Washington, Seattle, Washington
| | - Jeffrey G Ojemann
- 1Department of Neurological Surgery, University of Washington, Seattle
- 2Division of Neurosurgery, Seattle Children's Hospital, Seattle
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
| | - Jason S Hauptman
- 1Department of Neurological Surgery, University of Washington, Seattle
- 2Division of Neurosurgery, Seattle Children's Hospital, Seattle
- 4Neurosciences Center, Seattle Children's Hospital, Seattle
| |
Collapse
|
10
|
Chen G, Hu J, Ran H, Nie L, Tang W, Li X, Li Q, He Y, Liu J, Song G, Xu G, Liu H, Zhang T. Alterations of Cerebral Perfusion and Functional Connectivity in Children With Idiopathic Generalized Epilepsy. Front Neurosci 2022; 16:918513. [PMID: 35769697 PMCID: PMC9236200 DOI: 10.3389/fnins.2022.918513] [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: 04/12/2022] [Accepted: 05/25/2022] [Indexed: 12/02/2022] Open
Abstract
Background Studies have demonstrated that adults with idiopathic generalized epilepsy (IGE) have functional abnormalities; however, the neuropathological pathogenesis differs between adults and children. This study aimed to explore alterations in the cerebral blood flow (CBF) and functional connectivity (FC) to comprehensively elucidate the neuropathological mechanisms of IGE in children. Methods We obtained arterial spin labeling (ASL) and resting state functional magnetic resonance imaging data of 28 children with IGE and 35 matched controls. We used ASL to determine differential CBF regions in children with IGE. A seed-based whole-brain FC analysis was performed for regions with significant CBF changes. The mean CBF and FC of brain areas with significant group differences was extracted, then its correlation with clinical variables in IGE group was analyzed by using Pearson correlation analysis. Results Compared to controls, children with IGE had CBF abnormalities that were mainly observed in the right middle temporal gyrus, right middle occipital gyrus (MOG), right superior frontal gyrus (SFG), left inferior frontal gyrus (IFG), and triangular part of the left IFG (IFGtriang). We observed that the FC between the left IFGtriang and calcarine fissure (CAL) and that between the right MOG and bilateral CAL were decreased in children with IGE. The CBF in the right SFG was correlated with the age at IGE onset. FC in the left IFGtriang and left CAL was correlated with the IGE duration. Conclusion This study found that CBF and FC were altered simultaneously in the left IFGtriang and right MOG of children with IGE. The combination of CBF and FC may provide additional information and insight regarding the pathophysiology of IGE from neuronal and vascular integration perspectives.
Collapse
|
11
|
Khalife MR, Scott RC, Hernan AE. Mechanisms for Cognitive Impairment in Epilepsy: Moving Beyond Seizures. Front Neurol 2022; 13:878991. [PMID: 35645970 PMCID: PMC9135108 DOI: 10.3389/fneur.2022.878991] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
There has been a major emphasis on defining the role of seizures in the causation of cognitive impairments like memory deficits in epilepsy. Here we focus on an alternative hypothesis behind these deficits, emphasizing the mechanisms of information processing underlying healthy cognition characterized as rate, temporal and population coding. We discuss the role of the underlying etiology of epilepsy in altering neural networks thereby leading to both the propensity for seizures and the associated cognitive impairments. In addition, we address potential treatments that can recover the network function in the context of a diseased brain, thereby improving both seizure and cognitive outcomes simultaneously. This review shows the importance of moving beyond seizures and approaching the deficits from a system-level perspective with the guidance of network neuroscience.
Collapse
Affiliation(s)
- Mohamed R. Khalife
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| | - Rod C. Scott
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
- Institute of Child Health, Neurosciences Unit University College London, London, United Kingdom
| | - Amanda E. Hernan
- Division of Neuroscience, Nemours Children's Health, Wilmington, DE, United States
- Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| |
Collapse
|
12
|
Pretreatment Topological Disruptions of Whole-brain Networks Exist in Childhood Absence Epilepsy: A Resting-state EEG-fMRI Study. Epilepsy Res 2022; 182:106909. [DOI: 10.1016/j.eplepsyres.2022.106909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 02/24/2022] [Accepted: 03/13/2022] [Indexed: 11/19/2022]
|
13
|
Laghouati E, Studer F, Depaulis A, Guillemain I. Early alterations of the neuronal network processing whisker-related sensory signal during absence epileptogenesis. Epilepsia 2021; 63:497-509. [PMID: 34919740 DOI: 10.1111/epi.17151] [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] [Received: 08/16/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Epileptogenesis is the particular process during which the epileptic network builds up progressively before the onset of the first seizures. Whether physiological functions are impacted by this development of epilepsy remains unclear. To explore this question, we used Genetic Absence Epilepsy Rats From Strasbourg (GAERS), in which spike-and-wave discharges are initiated in the whisker primary somatosensory cortex (wS1) and first occur during cortical maturation. We studied the development of both the epileptic and the physiological wS1 circuits during cortical maturation to understand the interactions between them and the consequences for the animals' behavior. METHODS In sedated and immobilized rat pups, we recorded in vivo epileptic and whisker sensory evoked activities across the wS1 and thalamus using multicontact electrodes. We compared sensory evoked potentials based on current source density analysis. We then analyzed the multiunit activities evoked by whisker stimulation in GAERS and control rats. Finally, we evaluated behavioral performance dependent on the functionality of the wS1 cortex using the gap-crossing task. RESULTS We showed that the epileptic circuit changed during the epileptogenesis period in GAERS, by involving different cortical layers of wS1. Neuronal activities evoked by whisker stimulation were reduced in the wS1 cortex at P15 and P30 in GAERS but increased in the ventral posteromedial nucleus of the thalamus at P15 and in the posterior medial nucleus at P30, when compared to control rats. Finally, we observed lower performance in GAERS versus controls, at both P15 and P30, in a whisker-mediated behavioral task. SIGNIFICANCE Our data show that the functionality of wS1 cortex and thalamus is altered early during absence epileptogenesis in GAERS and then evolves before spike-and-wave discharges are fully expressed. They suggest that the development of the pathological circuit disturbs the physiological one and may be responsible for both the emergence of seizures and associated comorbidities.
Collapse
Affiliation(s)
- Emel Laghouati
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
| | - Florian Studer
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
| | - Antoine Depaulis
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
| | - Isabelle Guillemain
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
| |
Collapse
|
14
|
Hermann BP, Struck AF, Busch RM, Reyes A, Kaestner E, McDonald CR. Neurobehavioural comorbidities of epilepsy: towards a network-based precision taxonomy. Nat Rev Neurol 2021; 17:731-746. [PMID: 34552218 PMCID: PMC8900353 DOI: 10.1038/s41582-021-00555-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2021] [Indexed: 02/06/2023]
Abstract
Cognitive and behavioural comorbidities are prevalent in childhood and adult epilepsies and impose a substantial human and economic burden. Over the past century, the classic approach to understanding the aetiology and course of these comorbidities has been through the prism of the medical taxonomy of epilepsy, including its causes, course, characteristics and syndromes. Although this 'lesion model' has long served as the organizing paradigm for the field, substantial challenges to this model have accumulated from diverse sources, including neuroimaging, neuropathology, neuropsychology and network science. Advances in patient stratification and phenotyping point towards a new taxonomy for the cognitive and behavioural comorbidities of epilepsy, which reflects the heterogeneity of their clinical presentation and raises the possibility of a precision medicine approach. As we discuss in this Review, these advances are informing the development of a revised aetiological paradigm that incorporates sophisticated neurobiological measures, genomics, comorbid disease, diversity and adversity, and resilience factors. We describe modifiable risk factors that could guide early identification, treatment and, ultimately, prevention of cognitive and broader neurobehavioural comorbidities in epilepsy and propose a road map to guide future research.
Collapse
Affiliation(s)
- Bruce P. Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,
| | - Aaron F. Struck
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,William S. Middleton Veterans Administration Hospital, Madison, WI, USA
| | - Robyn M. Busch
- Epilepsy Center and Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA.,Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Anny Reyes
- Department of Psychiatry and Center for Multimodal Imaging and Genetics, University of California, San Diego, San Diego, CA, USA
| | - Erik Kaestner
- Department of Psychiatry and Center for Multimodal Imaging and Genetics, University of California, San Diego, San Diego, CA, USA
| | - Carrie R. McDonald
- Department of Psychiatry and Center for Multimodal Imaging and Genetics, University of California, San Diego, San Diego, CA, USA
| |
Collapse
|
15
|
Zhang K, Sun J, Sun Y, Niu K, Wang P, Wu C, Chen Q, Wang X. Pretreatment Source Location and Functional Connectivity Network Correlated With Therapy Response in Childhood Absence Epilepsy: A Magnetoencephalography Study. Front Neurol 2021; 12:692126. [PMID: 34413824 PMCID: PMC8368437 DOI: 10.3389/fneur.2021.692126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/07/2021] [Indexed: 11/30/2022] Open
Abstract
Objective: This study aims to investigate the differences between antiepileptic drug (AED) responders and nonresponders among patients with childhood absence epilepsy (CAE) using magnetoencephalography (MEG) and to additionally evaluate whether the neuromagnetic signals of the brain neurons were correlated with the response to therapy. Methods: Twenty-four drug-naïve patients were subjected to MEG under six frequency bandwidths during ictal periods. The source location and functional connectivity were analyzed using accumulated source imaging and correlation analysis, respectively. All patients were treated with appropriate AED, at least 1 year after their MEG recordings, their outcome was assessed, and they were consequently divided into responders and nonresponders. Results: The source location of the nonresponders was mainly in the frontal cortex at a frequency range of 8–12 and 30–80 Hz, especially 8–12 Hz, while the source location of the nonresponders was mostly in the medial frontal cortex, which was chosen as the region of interest. The nonresponders showed strong positive local frontal connections and deficient anterior and posterior connections at 80–250 Hz. Conclusion: The frontal cortex and especially the medial frontal cortex at α band might be relevant to AED-nonresponsive CAE patients. The local frontal positive epileptic network at 80–250 Hz in our study might further reveal underlying cerebral abnormalities even before treatment in CAE patients, which could cause them to be nonresponsive to AED. One single mechanism cannot explain AED resistance; the nonresponders may represent a subgroup of CAE who is refractory to several antiepileptic drugs.
Collapse
Affiliation(s)
- Ke Zhang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Jintao Sun
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Yulei Sun
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Kai Niu
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Pengfei Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Caiyun Wu
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Qiqi Chen
- MEG Center, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaoshan Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| |
Collapse
|
16
|
Gobbo D, Scheller A, Kirchhoff F. From Physiology to Pathology of Cortico-Thalamo-Cortical Oscillations: Astroglia as a Target for Further Research. Front Neurol 2021; 12:661408. [PMID: 34177766 PMCID: PMC8219957 DOI: 10.3389/fneur.2021.661408] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/11/2021] [Indexed: 12/21/2022] Open
Abstract
The electrographic hallmark of childhood absence epilepsy (CAE) and other idiopathic forms of epilepsy are 2.5-4 Hz spike and wave discharges (SWDs) originating from abnormal electrical oscillations of the cortico-thalamo-cortical network. SWDs are generally associated with sudden and brief non-convulsive epileptic events mostly generating impairment of consciousness and correlating with attention and learning as well as cognitive deficits. To date, SWDs are known to arise from locally restricted imbalances of excitation and inhibition in the deep layers of the primary somatosensory cortex. SWDs propagate to the mostly GABAergic nucleus reticularis thalami (NRT) and the somatosensory thalamic nuclei that project back to the cortex, leading to the typical generalized spike and wave oscillations. Given their shared anatomical basis, SWDs have been originally considered the pathological transition of 11-16 Hz bursts of neural oscillatory activity (the so-called sleep spindles) occurring during Non-Rapid Eye Movement (NREM) sleep, but more recent research revealed fundamental functional differences between sleep spindles and SWDs, suggesting the latter could be more closely related to the slow (<1 Hz) oscillations alternating active (Up) and silent (Down) cortical activity and concomitantly occurring during NREM. Indeed, several lines of evidence support the fact that SWDs impair sleep architecture as well as sleep/wake cycles and sleep pressure, which, in turn, affect seizure circadian frequency and distribution. Given the accumulating evidence on the role of astroglia in the field of epilepsy in the modulation of excitation and inhibition in the brain as well as on the development of aberrant synchronous network activity, we aim at pointing at putative contributions of astrocytes to the physiology of slow-wave sleep and to the pathology of SWDs. Particularly, we will address the astroglial functions known to be involved in the control of network excitability and synchronicity and so far mainly addressed in the context of convulsive seizures, namely (i) interstitial fluid homeostasis, (ii) K+ clearance and neurotransmitter uptake from the extracellular space and the synaptic cleft, (iii) gap junction mechanical and functional coupling as well as hemichannel function, (iv) gliotransmission, (v) astroglial Ca2+ signaling and downstream effectors, (vi) reactive astrogliosis and cytokine release.
Collapse
Affiliation(s)
- Davide Gobbo
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Anja Scheller
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| |
Collapse
|
17
|
Li R, Ryu JH, Vincent P, Springer M, Kluger D, Levinsohn EA, Chen Y, Chen H, Blumenfeld H. The pulse: transient fMRI signal increases in subcortical arousal systems during transitions in attention. Neuroimage 2021; 232:117873. [PMID: 33647499 DOI: 10.1016/j.neuroimage.2021.117873] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/02/2021] [Accepted: 02/12/2021] [Indexed: 01/02/2023] Open
Abstract
Studies of attention emphasize cortical circuits for salience monitoring and top-down control. However, subcortical arousal systems have a major influence on dynamic cortical state. We hypothesize that task-related increases in attention begin with a "pulse" in subcortical arousal and cortical attention networks, which are reflected indirectly through transient fMRI signals. We conducted general linear model and model-free analyses of fMRI data from two cohorts and tasks with mixed block and event-related design. 46 adolescent subjects at our center and 362 normal adults from the Human Connectome Project participated. We identified a core shared network of transient fMRI increases in subcortical arousal and cortical salience/attention networks across cohorts and tasks. Specifically, we observed a transient pulse of fMRI increases both at task block onset and with individual task events in subcortical arousal areas including midbrain tegmentum, thalamus, nucleus basalis and striatum; cortical-subcortical salience network regions including the anterior insula/claustrum and anterior cingulate cortex/supplementary motor area; in dorsal attention network regions including dorsolateral frontal cortex and inferior parietal lobule; as well as in motor regions including cerebellum, and left hemisphere hand primary motor cortex. The transient pulse of fMRI increases in subcortical and cortical arousal and attention networks was consistent across tasks and study populations, whereas sustained activity in these same networks was more variable. The function of the transient pulse in these networks is unknown. However, given its anatomical distribution, it could participate in a neuromodulatory surge of activity in multiple parallel neurotransmitter systems facilitating dynamic changes in conscious attention.
Collapse
Affiliation(s)
- Rong Li
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States; MOE Key Lab for Neuroinformation, 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 610054, P R China
| | - Jun Hwan Ryu
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Peter Vincent
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Max Springer
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Dan Kluger
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Erik A Levinsohn
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Yu Chen
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
| | - Huafu Chen
- MOE Key Lab for Neuroinformation, 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 610054, P R China
| | - Hal Blumenfeld
- Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States; Departments of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States; Departments of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States.
| |
Collapse
|
18
|
Li R, Zhang L, Guo D, Zou T, Wang X, Wang H, Li J, Wang C, Liu D, Yang Z, Xiao B, Chen H, Feng L. Temporal Lobe Epilepsy Shows Distinct Functional Connectivity Patterns in Different Thalamic Nuclei. Brain Connect 2021; 11:119-131. [PMID: 33317410 DOI: 10.1089/brain.2020.0826] [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] [Indexed: 12/28/2022] Open
Abstract
Background: The thalamus, as a key relay of neuronal information flow between subcortical structures and cortical networks, has been implicated in focal limbic seizures propagation, awareness maintenance, and seizure-related cognitive deficits. However, the specific functional alterations between different thalamic nuclei and subcortical-cortical systems in temporal lobe epilepsy (TLE) remain largely unknown. Methods: We examined thalamic functional connectivity (FC) in 26 TLE patients and 30 healthy controls matched for sex, age, and education. The anterior (ANT), ventral posterior medial, and central lateral nuclei of thalamus were employed to establish whole-brain seed-to-voxel thalamic FC maps. Secondary Pearson's correlation analysis was conducted to assess associations between the abnormal thalamic FC and the memory performance in TLE. Results: Seed-based FC analyses revealed typical distinct FC patterns within each thalamic nuclei in both controls and TLE patients. The TLE showed significantly decreased FC between different thalamic nuclei and subcortical-cortical networks, including the limbic structures, midbrain, sensorimotor network, medial prefrontal cortex, temporal-occipital fusiform gyrus, and cerebellum. Verification analyses yielded similar patterns of thalamic FC changes in TLE. Importantly, the decreased FC between the ANT and hippocampal pathway was correlated with the poorer memory performance of TLE. Conclusion: These findings suggest that the distinct thalamocortical FC patterns are damaged to some extent in TLE patients. Importantly, the specific pathology of the ANT-hippocampal pathway in TLE may be a potential factor that contributes to memory deficits. Our study may pave the way for improved treatments and cognitive function by directly targeting different thalamocortical circuits for TLE.
Collapse
Affiliation(s)
- Rong Li
- MOE Key Lab for Neuroinformation, 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, P.R. China
| | - Leiyao Zhang
- MOE Key Lab for Neuroinformation, 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, P.R. China
| | - Danni Guo
- Department of Neurology and Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Ting Zou
- MOE Key Lab for Neuroinformation, 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, P.R. China
| | - Xuyang Wang
- MOE Key Lab for Neuroinformation, 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, P.R. China
| | - Hongyu Wang
- MOE Key Lab for Neuroinformation, 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, P.R. China
| | - Jiyi Li
- MOE Key Lab for Neuroinformation, 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, P.R. China
| | - Chong Wang
- MOE Key Lab for Neuroinformation, 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, P.R. China
| | - Dingyang Liu
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Zhiquan Yang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Bo Xiao
- Department of Neurology and Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Huafu Chen
- MOE Key Lab for Neuroinformation, 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, P.R. China.,Sichuan Provincial Center for Mental Health, The Center of Psychosomatic Medicine of Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, P.R. China
| | - Li Feng
- Department of Neurology and Xiangya Hospital, Central South University, Changsha, P.R. China
| |
Collapse
|
19
|
Li R, Wang H, Wang L, Zhang L, Zou T, Wang X, Liao W, Zhang Z, Lu G, Chen H. Shared and distinct global signal topography disturbances in subcortical and cortical networks in human epilepsy. Hum Brain Mapp 2021; 42:412-426. [PMID: 33073893 PMCID: PMC7776006 DOI: 10.1002/hbm.25231] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/08/2020] [Accepted: 09/29/2020] [Indexed: 01/21/2023] Open
Abstract
Epilepsy is a common brain network disorder associated with disrupted large-scale excitatory and inhibitory neural interactions. Recent resting-state fMRI evidence indicates that global signal (GS) fluctuations that have commonly been ignored are linked to neural activity. However, the mechanisms underlying the altered global pattern of fMRI spontaneous fluctuations in epilepsy remain unclear. Here, we quantified GS topography using beta weights obtained from a multiple regression model in a large group of epilepsy with different subtypes (98 focal temporal epilepsy; 116 generalized epilepsy) and healthy population (n = 151). We revealed that the nonuniformly distributed GS topography across association and sensory areas in healthy controls was significantly shifted in patients. Particularly, such shifts of GS topography disturbances were more widespread and bilaterally distributed in the midbrain, cerebellum, visual cortex, and medial and orbital cortex in generalized epilepsy, whereas in focal temporal epilepsy, these networks spread beyond the temporal areas but mainly remain lateralized. Moreover, we found that these abnormal GS topography patterns were likely to evolve over the course of a longer epilepsy disease. Our study demonstrates that epileptic processes can potentially affect global excitation/inhibition balance and shift the normal GS topological distribution. These progressive topographical GS disturbances in subcortical-cortical networks may underlie pathophysiological mechanisms of global fluctuations in human epilepsy.
Collapse
Affiliation(s)
- Rong Li
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Hongyu Wang
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Liangcheng Wang
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Leiyao Zhang
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Ting Zou
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Xuyang Wang
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Wei Liao
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Zhiqiang Zhang
- Department of Medical ImagingJinling Hospital, Nanjing University School of MedicineNanjingChina
| | - Guangming Lu
- Department of Medical ImagingJinling Hospital, Nanjing University School of MedicineNanjingChina
| | - Huafu Chen
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of ChinaChengduChina
- MOE Key Laboratory for Neuroinformation, High‐Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan ProvinceUniversity of Electronic Science and Technology of ChinaChengduChina
| |
Collapse
|
20
|
Crunelli V, Lőrincz ML, McCafferty C, Lambert RC, Leresche N, Di Giovanni G, David F. Clinical and experimental insight into pathophysiology, comorbidity and therapy of absence seizures. Brain 2020; 143:2341-2368. [PMID: 32437558 PMCID: PMC7447525 DOI: 10.1093/brain/awaa072] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/19/2019] [Accepted: 01/31/2020] [Indexed: 12/24/2022] Open
Abstract
Absence seizures in children and teenagers are generally considered relatively benign because of their non-convulsive nature and the large incidence of remittance in early adulthood. Recent studies, however, show that 30% of children with absence seizures are pharmaco-resistant and 60% are affected by severe neuropsychiatric comorbid conditions, including impairments in attention, cognition, memory and mood. In particular, attention deficits can be detected before the epilepsy diagnosis, may persist even when seizures are pharmacologically controlled and are aggravated by valproic acid monotherapy. New functional MRI-magnetoencephalography and functional MRI-EEG studies provide conclusive evidence that changes in blood oxygenation level-dependent signal amplitude and frequency in children with absence seizures can be detected in specific cortical networks at least 1 min before the start of a seizure, spike-wave discharges are not generalized at seizure onset and abnormal cortical network states remain during interictal periods. From a neurobiological perspective, recent electrical recordings and imaging of large neuronal ensembles with single-cell resolution in non-anaesthetized models show that, in contrast to the predominant opinion, cortical mechanisms, rather than an exclusively thalamic rhythmogenesis, are key in driving seizure ictogenesis and determining spike-wave frequency. Though synchronous ictal firing characterizes cortical and thalamic activity at the population level, individual cortico-thalamic and thalamocortical neurons are sparsely recruited to successive seizures and consecutive paroxysmal cycles within a seizure. New evidence strengthens previous findings on the essential role for basal ganglia networks in absence seizures, in particular the ictal increase in firing of substantia nigra GABAergic neurons. Thus, a key feature of thalamic ictogenesis is the powerful increase in the inhibition of thalamocortical neurons that originates at least from two sources, substantia nigra and thalamic reticular nucleus. This undoubtedly provides a major contribution to the ictal decrease in total firing and the ictal increase of T-type calcium channel-mediated burst firing of thalamocortical neurons, though the latter is not essential for seizure expression. Moreover, in some children and animal models with absence seizures, the ictal increase in thalamic inhibition is enhanced by the loss-of-function of the astrocytic GABA transporter GAT-1 that does not necessarily derive from a mutation in its gene. Together, these novel clinical and experimental findings bring about paradigm-shifting views of our understanding of absence seizures and demand careful choice of initial monotherapy and continuous neuropsychiatric evaluation of affected children. These issues are discussed here to focus future clinical and experimental research and help to identify novel therapeutic targets for treating both absence seizures and their comorbidities.
Collapse
Affiliation(s)
- Vincenzo Crunelli
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.,Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK
| | - Magor L Lőrincz
- Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK.,Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary.,Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Cian McCafferty
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Régis C Lambert
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine and Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Nathalie Leresche
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine and Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Giuseppe Di Giovanni
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.,Neuroscience Division, School of Bioscience, Cardiff University, Museum Avenue, Cardiff, UK
| | - François David
- Cerebral dynamics, learning and plasticity, Integrative Neuroscience and Cognition Center - UMR 8002, Paris, France
| |
Collapse
|
21
|
Zhang T, Zhang Y, Ren J, Yang C, Zhou H, Li L, Lei D, Gong Q, Zhou D, Yang T. Aberrant basal ganglia-thalamo-cortical network topology in juvenile absence epilepsy: A resting-state EEG-fMRI study. Seizure 2020; 84:78-83. [PMID: 33307464 DOI: 10.1016/j.seizure.2020.11.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/22/2020] [Accepted: 11/28/2020] [Indexed: 02/05/2023] Open
Abstract
PURPOSE The underlying pathophysiology of juvenile absence epilepsy (JAE) is unclear. Since cortical and subcortical brain regions are thought to be altered in genetic generalized epilepsy, the present study examined the resting-state functional network topology of the same regions in JAE. METHODS Electroencephalography and functional magnetic resonance imaging (EEG-fMRI) were performed on 18 JAE patients and 28 healthy controls (HCs). The topology of functional networks was analyzed using the graph-theoretic method. Both global and nodal network parameters were calculated, and parameters differing significantly between the two groups were correlated with clinical variables. RESULTS Both JAE patients and HCs had small-world functional network topological architectures. However, JAE patients showed higher values for the global parameters of clustering coefficient (Cp) and normalized characteristic path length (Lambda). At the nodal level, patients exhibited greater centrality at widespread cortices, including the left superior parietal gyrus, right superior temporal gyrus, right orbital part of middle frontal gyrus and bilateral supplementary motor area. Conversely, patients showed decreased nodal centrality predominantly in the limbic network, left thalamus and right caudate nucleus. Degree centrality in the right hippocampus and betweenness centrality in the right caudate nucleus positively correlated with epilepsy duration. CONCLUSION The global functional network of JAE shows small-world properties, but tends to be regular with higher segregation and lower integration. Regions in the basal ganglia-thalamo-cortical network have aberrant nodal centrality. The hippocampus and caudate nucleus may reorganize as epilepsy progresses. Our findings indicate the pathogenesis and compensatory mechanisms to seizure attacks and cognitive deficits of JAE.
Collapse
Affiliation(s)
- Tianyu Zhang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yingying Zhang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jiechuan Ren
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Cheng Yang
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Huanyu Zhou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Lei Li
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Du Lei
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Qiyong Gong
- Huaxi MR Research Center, Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Dong Zhou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Tianhua Yang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| |
Collapse
|
22
|
Quantitative characteristics of spike-wave paroxysms in genetic generalized epilepsy. Clin Neurophysiol 2020; 131:1230-1240. [DOI: 10.1016/j.clinph.2020.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/17/2020] [Accepted: 03/12/2020] [Indexed: 11/20/2022]
|
23
|
Abstract
Epilepsy is considered a disease characterized by an underlying predisposition to seizures as well as neurobiologic, cognitive, psychologic, and social consequences. It is the most frequent chronic neurologic condition of childhood, affecting 0.5%-1% of children worldwide. It comprises a variety of disorders with many different etiologies, consequently affecting management and outcome. Although the great majority of children have epilepsies that are self-limited and have a good prognosis, it is nevertheless very well recognized that epileptic activity (be it seizures or interictal discharges) can be particularly deleterious to the developing brain acting as a disruptor to normal developmental function. Indeed, epilepsy and neurocognitive and behavioral disorders very frequently coexist, and it can be challenging to understand if there is causality or if they are all the reflection of the underlying brain disorder. Hence, accurate phenotypic and etiologic diagnosis is of utmost importance as it will not only guide decision making with regard to choice of treatment but also enable management of expectations concerning outcome. The current chapter aims to provide a general overview of the fast evolving and vast field of childhood epilepsy from its definition and epidemiology, to its diagnostic challenges, management, and outcome.
Collapse
Affiliation(s)
- Filipa Bastos
- University College London National Institute of Health Research Biomedical Research Centre, Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom; Centre Hospitalier Universitaire de Lausanne, Child Neurology and Neurorehabilitation Unit, University of Lausanne, Lausanne, Switzerland
| | - J Helen Cross
- University College London National Institute of Health Research Biomedical Research Centre, Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom.
| |
Collapse
|
24
|
Fonseca Wald ELA, Hendriksen JGM, Drenthen GS, Kuijk SMJV, Aldenkamp AP, Vles JSH, Vermeulen RJ, Debeij-van Hall MHJA, Klinkenberg S. Towards a Better Understanding of Cognitive Deficits in Absence Epilepsy: a Systematic Review and Meta-Analysis. Neuropsychol Rev 2019; 29:421-449. [PMID: 31776780 PMCID: PMC6892766 DOI: 10.1007/s11065-019-09419-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/21/2019] [Indexed: 12/30/2022]
Abstract
Cognition in absence epilepsy (AE) is generally considered undisturbed. However, reports on cognitive deficits in AE in recent years have suggested otherwise. This review systematically assesses current literature on cognitive performance in children with AE. A systematic literature search was performed in Pubmed, Embase, Cochrane and Web of Science. All studies reporting on cognitive performance in children with AE were considered. In total 33 studies were eligible for inclusion. Neuropsychological tests were classified into the following domains: intelligence; executive function; attention; language; motor & sensory-perceptual examinations; visuoperceptual/visuospatial/visuoconstructional function; memory and learning; achievement. Random-effect meta-analyses were conducted by estimating the pooled mean and/or pooling the mean difference in case-control studies. Full-scale IQ in children with AE was estimated at 96.78 (95%CI:94.46–99.10) across all available studies and in case-control studies IQ was on average 8.03 (95%CI:-10.45- -5.61) lower. Verbal IQ was estimated at 97.98 (95%CI:95.80–100.16) for all studies and 9.01 (95%CI:12.11- -5.90) points lower in case-control studies. Performance IQ was estimated at 97.23 (93.24–101.22) for all available studies and 5.32 (95%CI:-8.27–2.36) points lower in case-control studies. Lower performance was most often reported in executive function (cognitive flexibility, planning, and verbal fluency) and attention (sustained, selective and divided attention). Reports on school difficulties, neurodevelopmental problems, and attentional problems were high. In conclusion, in contrast to common beliefs, lower than average neurocognitive performance was noted in multiple cognitive domains, which may influence academic and psychosocial development.
Collapse
Affiliation(s)
- Eric L A Fonseca Wald
- Department of Neurology, Maastricht University Medical Center+, 6202, AZ, Maastricht, The Netherlands. .,Epilepsy Center Kempenhaeghe, Heeze, The Netherlands. .,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - Jos G M Hendriksen
- Department of Neurology, Maastricht University Medical Center+, 6202, AZ, Maastricht, The Netherlands.,Epilepsy Center Kempenhaeghe, Heeze, The Netherlands
| | - Gerald S Drenthen
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Sander M J V Kuijk
- Department of KEMTA, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Albert P Aldenkamp
- Department of Neurology, Maastricht University Medical Center+, 6202, AZ, Maastricht, The Netherlands.,Epilepsy Center Kempenhaeghe, Heeze, The Netherlands.,Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Johan S H Vles
- Department of Neurology, Maastricht University Medical Center+, 6202, AZ, Maastricht, The Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - R Jeroen Vermeulen
- Department of Neurology, Maastricht University Medical Center+, 6202, AZ, Maastricht, The Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | | | - Sylvia Klinkenberg
- Department of Neurology, Maastricht University Medical Center+, 6202, AZ, Maastricht, The Netherlands. .,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| |
Collapse
|
25
|
Bear JJ, Chapman KE, Tregellas JR. The epileptic network and cognition: What functional connectivity is teaching us about the childhood epilepsies. Epilepsia 2019; 60:1491-1507. [PMID: 31247129 PMCID: PMC7175745 DOI: 10.1111/epi.16098] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/09/2019] [Accepted: 06/05/2019] [Indexed: 12/13/2022]
Abstract
Our objective was to summarize and evaluate the rapidly expanding body of literature studying functional connectivity in childhood epilepsy. In the self-limited childhood epilepsies, awareness of cognitive comorbidities has been steadily increasing, and recent advances in our understanding of the network effects of these disorders promise insights into the underlying neurobiology. We reviewed publications addressing functional connectivity in children with epilepsy with an emphasis on studies of children with self-limited childhood epilepsies. The majority of studies have been published in the past 10 years and predominantly examine childhood epilepsy with centrotemporal spikes and childhood absence epilepsy. Cognitive network alterations are commonly observed across the childhood epilepsies. Some of these effects appear to be nonspecific to epilepsy syndrome or even to category of neurological disorder. Other patterns, such as changes in the connectivity of cortical language areas in childhood epilepsy with centrotemporal spikes, provide clues to the underlying cognitive deficits seen in affected children. The literature to date is dominated by general observations of connectivity patterns without a priori hypotheses. These data-driven studies build an important foundation for hypothesis generation and are already providing useful insights into the neuropathology of the childhood epilepsies. Future work should emphasize hypothesis-driven approaches and rigorous clinical correlations to better understand how the knowledge of network alterations can be applied to guidance and treatment for the children in our clinics.
Collapse
Affiliation(s)
- Joshua J Bear
- Department of Pediatrics, Section of Neurology, Children’s Hospital Colorado
- Department of Pediatrics, University of Colorado Anschutz Medical Campus
| | - Kevin E Chapman
- Department of Pediatrics, Section of Neurology, Children’s Hospital Colorado
- Department of Pediatrics, University of Colorado Anschutz Medical Campus
| | - Jason R Tregellas
- Department of Psychiatry, University of Colorado Anschutz Medical Campus
- Research Service, Rocky Mountain Regional VA Medical Center
| |
Collapse
|
26
|
Young JC, Nasser HM, Casillas-Espinosa PM, O'Brien TJ, Jackson GD, Paolini AG. Multiunit cluster firing patterns of piriform cortex and mediodorsal thalamus in absence epilepsy. Epilepsy Behav 2019; 97:229-243. [PMID: 31254843 DOI: 10.1016/j.yebeh.2019.05.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/09/2019] [Accepted: 05/20/2019] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The objective of the study were to investigate patterns of multiunit cluster firing in the piriform cortex (PC) and mediodorsal thalamus (MDT) in a rat model of genetic generalized epilepsy (GGE) with absence seizures and to assess whether these regions contribute to the initiation or spread of generalized epileptiform discharges. METHODS Multiunit clusters and their corresponding local field potentials (LFPs) were recorded from microelectrode arrays implanted in the PC and MDT in urethane anesthetized Genetic Absence Epilepsy Rats from Strasbourg (GAERS) and nonepileptic control (NEC) rats. Peristimulus time histograms (PSTHs) and cross-correlograms were used to observe transient changes in both the rate of firing and synchrony over time. The phase locking of multiunit clusters to LFP signals (spike-LFP phase locking) was calculated for frequency bands associated with olfactory communication between the two brain regions. RESULTS There were significant increases in both rate of firing and synchronous activity at the onset of generalized epileptiform discharges in both PC and MDT. Prior to and following these increases in synchronous activity, there were periods of suppression. Significant increases in spike-LFP phase locking were observed within the PC prior to the onset of epileptiform discharges across all spectral bands. There were also significant increases in spike-LFP phase locking within the theta band of the MDT prior to onset. Between the two brain regions, there was a significant decrease in spike-LFP phase locking -0.5 s prior to onset in the theta band which coincided with a significant elevation in spike-LFP phase locking in the gamma band. CONCLUSIONS Both the PC and MDT are engaged in the absence epilepsy network. Early spike-LFP phase locking between these two brain regions suggests potential involvement in the initiation of seizure activity.
Collapse
Affiliation(s)
- James C Young
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia.
| | - Helen M Nasser
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia; ISN Psychology - Institute for Social Neuroscience, Melbourne, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Monash University, Melbourne, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, The University of Melbourne, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Monash University, Melbourne, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, The University of Melbourne, Australia
| | - Graeme D Jackson
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia; Department of Neurology, Austin Health, Melbourne, Australia
| | - Antonio G Paolini
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia; ISN Psychology - Institute for Social Neuroscience, Melbourne, Australia; School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| |
Collapse
|
27
|
Cortical morphologic changes in recent-onset, drug-naïve idiopathic generalized epilepsy. Magn Reson Imaging 2019; 61:137-142. [PMID: 31129280 DOI: 10.1016/j.mri.2019.05.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 05/20/2019] [Accepted: 05/22/2019] [Indexed: 02/05/2023]
Abstract
PURPOSE Only a few studies have investigated the brain morphology abnormalities in structural MRI in patients with drug-naïve idiopathic generalized epilepsy (IGE) and mainly focused on brain volume changes. In the present study, we aimed to investigate the changes in three morphologic measurement differences including cortical thickness, cortical volume, and surface area using FreeSurfer in a pediatric cohort of recent-onset, drug-naïve IGE. METHODS Forty-five recent-onset, drug-naïve patients diagnosed with IGE and 32 demographically matched healthy controls were recruited. All participants underwent structural MRI scans with a 3.0 T MR system. FreeSurfer, an automated cortical surface reconstruction toolbox, was applied to compare the cortical morphology between patients and controls. The brain regions with significant group differences after multiple comparison correction were extracted in common space for each patient, and then correlated with their clinical characteristics (including onset age, duration of epilepsy, and mini-mental state examination (MMSE)) using partial correlation analysis with age, sex and intracranial volume as covariates. RESULTS Compared with controls, IGE patients showed decreased cortical thickness in the left rostral middle frontal gyrus, decreased cortical volume in the right cuneus and left superior frontal gyrus that extended to the precentral gyrus, and decreased surface area in the right cuneus and right inferior parietal gyrus. None of these regions showed significant relationships with clinical measurements in the patient group. CONCLUSION Our findings suggest that cortical thickness, cortical volume, and surface area changes occurred in the early stage of IGE. These findings provide structural neuroimaging evidence underlying the pathology of IGE.
Collapse
|
28
|
Multifocal epilepsy in children is associated with increased long-distance functional connectivity: An explorative EEG-fMRI study. Eur J Paediatr Neurol 2018; 22:1054-1065. [PMID: 30017619 DOI: 10.1016/j.ejpn.2018.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 06/12/2018] [Accepted: 07/01/2018] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Multifocal epileptic activity is an unfavourable feature of a number of epileptic syndromes (Lennox-Gastaut syndrome, West syndrome, severe focal epilepsies) which suggests an overall vulnerability of the brain to pathological synchronization. However, the mechanisms of multifocal activity are insufficiently understood. This explorative study investigates whether pathological connectivity within brain areas of the default mode network as well as thalamus, brainstem and retrosplenial cortex may predispose individuals to multifocal epileptic activity. METHODS 33 children suffering from multifocal and monofocal (control group) epilepsies were investigated using EEG-fMRI recordings during sleep. The blood oxygenated level dependent (BOLD) signal of 15 regions of interest was extracted and temporally correlated (resting-state functional connectivity). RESULTS Patients with monofocal epilepsies were characterized by strong correlations between the corresponding interhemispheric homotopic regions. This pattern of correlations with pronounced short-distance and weak long-distance functional connectivity resembles the connectivity pattern described for healthy children. Patients with multifocal epileptic activity, however, demonstrated significantly stronger correlations between a large number of regions of the default mode network as well as thalamus and brainstem, with a significant increase in long-distance connectivity compared to children with monofocal epileptic activity. In the group of patients with multifocal epilepsies there were no differences in functional connectivity between patients with or without Lennox-Gastaut syndrome. CONCLUSION This explorative study shows that multifocal activity is associated with generally increased long-distance functional connectivity in the brain. It can be suggested that this pronounced connectivity may represent either a risk to pathological over-synchronization or a consequence of the multifocal epileptic activity.
Collapse
|
29
|
Amyloid causes intermittent network disruptions in cognitively intact older subjects. Brain Imaging Behav 2018; 13:699-716. [DOI: 10.1007/s11682-018-9869-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
30
|
Savic I, Engel J. Reprint of "Structural and functional correlates of epileptogenesis--does gender matter?". Neurobiol Dis 2018; 72 Pt B:131-5. [PMID: 25448763 DOI: 10.1016/j.nbd.2014.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/15/2014] [Accepted: 05/22/2014] [Indexed: 11/30/2022] Open
Abstract
In the majority of neuropsychiatric conditions, marked gender-based differences have been found in the epidemiology,clinical manifestations, and therapy of disease. One possible reason is that sex differences in cerebral morphology, structural and functional connections, render men and women differentially vulnerable to various disease processes. The present review addresses this issue with respect to the functional and structural correlates to some forms of epilepsy.
Collapse
|
31
|
Abstract
Early-life epilepsies are a series of disorders frequently accompanied by a broad range of morbidities that include cognitive, behavioral, neuromuscular, and sleep disturbances; enteric and other forms of autonomic dysfunction; sensory processing difficulties; and other issues. Usually these morbidities cluster together in a single patient. Rather than these being separate conditions, all, including the seizures, are manifestations or coexpressions of developmental brain disorders. Instead of viewing epilepsy as the disease and the other features as comorbidities, approaching early-life epilepsies as part of the spectrum of developmental brain disorders could have implications for multidisciplinary care models, anticipatory guidance, and counseling of parents, as well as the design of randomized trials and targeting important outcomes. Ultimately, such an approach could improve understanding and help optimize outcomes in these difficult to treat disorders of early childhood.
Collapse
|
32
|
Cheng D, Yan X, Gao Z, Xu K, Chen Q. Attention Contributes to Arithmetic Deficits in New-Onset Childhood Absence Epilepsy. Front Psychiatry 2017; 8:166. [PMID: 28959217 PMCID: PMC5604065 DOI: 10.3389/fpsyt.2017.00166] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 08/25/2017] [Indexed: 11/13/2022] Open
Abstract
Neuropsychological studies indicate that new-onset childhood absence epilepsy (CAE) is associated with deficits in attention and executive functioning. However, the contribution of these deficits to impaired academic performance remains unclear. We aimed to examine whether attention and executive functioning deficits account for the academic difficulties prevalent in patients with new-onset CAE. We analyzed cognitive performance in several domains, including language, mathematics, psychomotor speed, spatial ability, memory, general intelligence, attention, and executive functioning, in 35 children with new-onset CAE and 33 control participants. Patients with new-onset CAE exhibited deficits in mathematics, general intelligence, attention, and executive functioning. Furthermore, attention deficits, as measured by a visual tracing task, accounted for impaired arithmetic performance in the new-onset CAE group. Therefore, attention deficits, rather than impaired general intelligence or executive functioning, may be responsible for arithmetic performance deficits in patients with new-onset CAE.
Collapse
Affiliation(s)
- Dazhi Cheng
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Xiuxian Yan
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Zhijie Gao
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Keming Xu
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Qian Chen
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| |
Collapse
|
33
|
de Pasquale F, Della Penna S, Sabatini U, Caravasso Falletta C, Peran P. The anatomical scaffold underlying the functional centrality of known cortical hubs. Hum Brain Mapp 2017; 38:5141-5160. [PMID: 28681960 DOI: 10.1002/hbm.23721] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 05/17/2017] [Accepted: 06/27/2017] [Indexed: 11/10/2022] Open
Abstract
Cortical hubs play a fundamental role in the functional architecture of brain connectivity at rest. However, the anatomical scaffold underlying their centrality is still under debate. Certainly, the brain function and anatomy are significantly entwined through synaptogenesis and pruning mechanisms that continuously reshape structural and functional connections. Thus, if hubs are expected to exhibit a large number of direct anatomical connections with the rest of the brain, such a dense wiring is extremely inefficient in energetic terms. In this work, we investigate these aspects on fMRI and DTI data from a set of know resting-state networks, starting from the hypothesis that to promote integration, functional, and anatomical connections link different areas at different scales or hierarchies. Thus, we focused on the role of functional hubs in this hierarchical organization of functional and anatomical architectures. We found that these regions, from a structural point of view, are first linked to each other and successively to the rest of the brain. Thus, functionally central nodes seem to show few strong anatomical connections. These findings suggest an efficient strategy of the investigated cortical hubs in exploiting few direct anatomical connections to link functional hubs among each other that eventually reach the rest of the considered nodes through local indirect tracts. Hum Brain Mapp 38:5141-5160, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Francesco de Pasquale
- Faculty of Veterinary Medicine, University of Teramo, Italy.,Department of Radiology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Stefania Della Penna
- Department of Neuroscience Imaging and Clinical Science, University of Chieti, Italy
| | - Umberto Sabatini
- Neuroradiology Unit, Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Italy
| | | | - Patrice Peran
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| |
Collapse
|
34
|
Guo JN, Kim R, Chen Y, Negishi M, Jhun S, Weiss S, Ryu JH, Bai X, Xiao W, Feeney E, Rodriguez-Fernandez J, Mistry H, Crunelli V, Crowley MJ, Mayes LC, Constable RT, Blumenfeld H. Impaired consciousness in patients with absence seizures investigated by functional MRI, EEG, and behavioural measures: a cross-sectional study. Lancet Neurol 2017; 15:1336-1345. [PMID: 27839650 PMCID: PMC5504428 DOI: 10.1016/s1474-4422(16)30295-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 09/27/2016] [Accepted: 09/27/2016] [Indexed: 11/17/2022]
Abstract
Background Absence seizures are brief episodes of impaired consciousness characterized by staring and behavioral arrest. The neural underpinnings of impaired consciousness and of the variable severity of behavioral impairment observed from one absence seizure to the next are not well understood. We therefore compared fMRI and EEG changes in absence seizures with impaired task performance to seizures in which performance was spared. Methods Patients were recruited from 59 pediatric neurology practices including hospitals and neurology outpatient offices throughout the United States. We performed simultaneous electroencephalography (EEG), fMRI, and behavioral testing in children and adolescents aged 6 to 19 years with typical absence epilepsy. fMRI and EEG were analyzed using data-driven approaches without prior assumptions about signal time courses or spatial distributions. The main outcomes were fMRI and EEG amplitudes in seizures with impaired versus spared behavioral responses analysed by t-test. We also examined the timing of fMRI and EEG changes in seizures with impaired behavioral responses compared to seizures with spared responses. Findings 93 patients were enrolled between September 1, 2005 and January 1, 2013, and we captured a total of 1032 seizures in 39 patients. fMRI changes during seizures occurred sequentially in three functional brain networks previously well-validated in studies of normal subjects. Seizures associated with more impaired behavior showed higher fMRI amplitude in all three networks compared to seizures with spared performance. In the default-mode network fMRI, amplitude was 0·57 ± 0·26% for seizures with impaired and 0·40 ± 0·16% for seizures with spared behavioral responses (mean difference 017%; 95% CI: 0·11 to 0·23%; p < 0.0001). In the task-positive network, fMRI amplitude was 0·53 ± 0·29% for impaired and 0·39 ± 0·15% for spared seizures (mean difference 0·14%; 95% CI: 008 to 0·21%; p < 0.0001). In the sensorimotor-thalamic network, fMRI amplitude was 0·41 ± 0·25% for impaired and 0·34 ± 014% for spared seizures (mean difference 0 07%; 95% CI: 001 to 0·13%; p = 0.02). Seizures with impaired behavior also showed greater EEG power in widespread brain regions compared to seizures with spared behavior. Mean fractional EEG power in the frontal leads was 50·4 ± 15·2 for seizures with impaired and 24·8 ± 6·5 for seizures with spared behavior (mean difference 25·6; 95% CI: 210 to 30·3); middle leads 35·4 ± 6·5 for impaired, 13 3 ± 34 for spared seizures (mean difference 22·1; 95% CI: 20.0 to 24·1); posterior leads 41·6 ± 5·3 for impaired, 24·6 ± 86 for spared seizures (mean difference 170; 95% CI: 14·4 to 19·7); p < 00001 for all comparisons. Average seizure duration was longer for seizures with impaired behavior at 79 ± 66 s, compared to 3·8 ± 3.0 s for seizures with spared behavior (mean difference 4.1 s; 95% CI 3.0 to 5.3 s, p < 00001). However, larger amplitude fMRI and EEG signals occurred at the outset or even preceding seizures with impairment. Interpretation Impaired consciousness in absence seizures is related to the intensity of physiological changes in established networks affecting widespread regions of the brain. Increased EEG and fMRI amplitude occurs at the onset of seizures associated with behavioral impairment. These findings suggest that a vulnerable state may exist at the initiation of some seizures leading to greater physiological changes and altered consciousness.
Collapse
Affiliation(s)
- Jennifer N Guo
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Robert Kim
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Yu Chen
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Michiro Negishi
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Stephen Jhun
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Sarah Weiss
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Jun Hwan Ryu
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Xiaoxiao Bai
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Wendy Xiao
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Erin Feeney
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | | | - Hetal Mistry
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | | | - Michael J Crowley
- Child Study Center, Yale University School of Medicine, New Haven, CT, USA
| | - Linda C Mayes
- Child Study Center, Yale University School of Medicine, New Haven, CT, USA
| | - R Todd Constable
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA.
| |
Collapse
|
35
|
Altered Effective Connectivity Network in Childhood Absence Epilepsy: A Multi-frequency MEG Study. Brain Topogr 2017; 30:673-684. [PMID: 28286918 DOI: 10.1007/s10548-017-0555-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 02/07/2017] [Indexed: 12/11/2022]
Abstract
Using multi-frequency magnetoencephalography (MEG) data, we investigated whether the effective connectivity (EC) network of patients with childhood absence epilepsy (CAE) is altered during the inter-ictal period in comparison with healthy controls. MEG data from 13 untreated CAE patients and 10 healthy controls were recorded. Correlation analysis and Granger causality analysis were used to construct an EC network at the source level in eight frequency bands. Alterations in the spatial pattern and topology of the network in CAE were investigated by comparing the patients with the controls. The network pattern was altered mainly in 1-4 Hz, showing strong connections within the frontal cortex and weak connections in the anterior-posterior pathways. The EC involving the precuneus/posterior cingulate cortex (PC/PCC) significantly decreased in low-frequency bands. In addition, the parameters of graph theory were significantly altered in several low- and high-frequency bands. CAE patients display frequency-specific abnormalities in the network pattern even during the inter-ictal period, and the frontal cortex and PC/PCC might play crucial roles in the pathophysiology of CAE. The EC network of CAE patients was over-connective and random during the inter-ictal period. This study is the first to reveal the frequency-specific alteration in the EC network during the inter-ictal period in CAE patients. Multiple-frequency MEG data are useful in investigating the pathophysiology of CAE, which can serve as new biomarkers of this disorder.
Collapse
|
36
|
Abstract
Although neuropsychological studies have demonstrated specific cognitive impairments in children with childhood absence epilepsy (CAE), the potential role of the frontal lobe in these cognitive deficits remains unclear. We therefore evaluated cognitive functions related to and unrelated to the functionality of the frontal lobe in childhood absence epilepsy patients and control subjects. Thirty-seven childhood absence epilepsy patients and 37 age- and gender-matched healthy control subjects were recruited and assessed using a computerized neuropsychological test battery. Childhood absence epilepsy patients, especially a drug-naïve subgroup, showed cognitive deficits in reasoning, visual attention, and executive function, which are typical cognitive functions of the frontal lobe. In contrast, treated childhood absence epilepsy patients only exhibited cognitive deficits in visual attention. There were no significant between-group differences for other cognitive tests. Our findings suggest that frontal lobe-related cognitive deficits represent the characteristic neuropsychological profile associated with childhood absence epilepsy.
Collapse
Affiliation(s)
- Dazhi Cheng
- 1 Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Xiuxian Yan
- 1 Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Zhijie Gao
- 1 Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Keming Xu
- 1 Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Xinlin Zhou
- 2 National Key Laboratory of Cognitive Neuroscience and Learning, Institute of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Qian Chen
- 1 Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| |
Collapse
|
37
|
Xiao F, An D, Zhou D. Functional MRI-based connectivity analysis: A promising tool for the investigation of the pathophysiology and comorbidity of epilepsy. Seizure 2017; 44:37-41. [DOI: 10.1016/j.seizure.2016.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 09/14/2016] [Accepted: 10/03/2016] [Indexed: 12/25/2022] Open
|
38
|
Ji GJ, Yu Y, Miao HH, Wang ZJ, Tang YL, Liao W. Decreased Network Efficiency in Benign Epilepsy with Centrotemporal Spikes. Radiology 2016; 283:186-194. [PMID: 27631414 DOI: 10.1148/radiol.2016160422] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose To investigate the functional connectome alterations in benign epilepsy with centrotemporal spikes with respect to the occurrence of interictal epileptic discharges (IEDs) during functional magnetic resonance (MR) imaging. Materials and Methods This prospective study was approved by the local institutional review board and was HIPAA compliant. All participants were consecutively enrolled with written informed consent. Forty-three right-handed patients were classified into IED (n = 20, 13 girls and seven boys; mean age ± standard deviation, 9.00 years ± 1.95) and non-IED (n = 23, 11 girls and 12 boys; mean age, 10.22 years ± 2.13) groups on the basis of electroencephalographic data simultaneously recorded during resting-state functional MR imaging at 3.0 T. The functional connectome features (estimated with graph theoretical analysis) in patient groups and control subjects who were matched for sex, age, and education level (n = 28, all right-handed, 13 girls and 15 boys; mean age, 10.00 years ± 2.31) were compared by using one-way analysis of variance. Results Patients with IEDs and those without IEDs showed consistently abnormal global topology in their functional networks (ie, decreased global efficiency; P < .05) relative to that of control subjects, with no differences between the two patient groups (P > .05). Decreased regional efficiency and connectivity strength were observed in the patients with IEDs and those without (mainly in the perirolandic and frontal areas) relative to control subjects (P < .05). Moreover, the altered functional features significantly correlated with clinical characteristics (ie, disease duration and age at symptom onset, P < .05). Conclusion These findings suggest that decreased global and regional efficiency are prominent functional deficits in children with benign epilepsy with centrotemporal spikes and can be readily identified with resting-state functional MR imaging, irrespective of IEDs. © RSNA, 2016 Online supplemental material is available for this article.
Collapse
Affiliation(s)
- Gong-Jun Ji
- From the Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China (G.J.J.); Collaborative Innovation Centre of Neuropsychiatric Disorders and Mental Health, Anhui Province, China (G.J.J.); Department of Psychology, School of Education (G.J.J., H.H.M., W.L.), and Center for Cognition and Brain Disorders and the Affiliated Hospital (G.J.J., H.H.M., W.L.), Hangzhou Normal University, Hangzhou, China; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China (G.J.J., H.H.M., W.L.); Departments of Psychiatry (Y.Y.) and Neurology (Z.J.W., Y.L.T.), the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China; and Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China (W.L.)
| | - Yang Yu
- From the Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China (G.J.J.); Collaborative Innovation Centre of Neuropsychiatric Disorders and Mental Health, Anhui Province, China (G.J.J.); Department of Psychology, School of Education (G.J.J., H.H.M., W.L.), and Center for Cognition and Brain Disorders and the Affiliated Hospital (G.J.J., H.H.M., W.L.), Hangzhou Normal University, Hangzhou, China; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China (G.J.J., H.H.M., W.L.); Departments of Psychiatry (Y.Y.) and Neurology (Z.J.W., Y.L.T.), the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China; and Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China (W.L.)
| | - Huan-Huan Miao
- From the Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China (G.J.J.); Collaborative Innovation Centre of Neuropsychiatric Disorders and Mental Health, Anhui Province, China (G.J.J.); Department of Psychology, School of Education (G.J.J., H.H.M., W.L.), and Center for Cognition and Brain Disorders and the Affiliated Hospital (G.J.J., H.H.M., W.L.), Hangzhou Normal University, Hangzhou, China; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China (G.J.J., H.H.M., W.L.); Departments of Psychiatry (Y.Y.) and Neurology (Z.J.W., Y.L.T.), the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China; and Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China (W.L.)
| | - Zhong-Jin Wang
- From the Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China (G.J.J.); Collaborative Innovation Centre of Neuropsychiatric Disorders and Mental Health, Anhui Province, China (G.J.J.); Department of Psychology, School of Education (G.J.J., H.H.M., W.L.), and Center for Cognition and Brain Disorders and the Affiliated Hospital (G.J.J., H.H.M., W.L.), Hangzhou Normal University, Hangzhou, China; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China (G.J.J., H.H.M., W.L.); Departments of Psychiatry (Y.Y.) and Neurology (Z.J.W., Y.L.T.), the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China; and Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China (W.L.)
| | - Ye-Lei Tang
- From the Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China (G.J.J.); Collaborative Innovation Centre of Neuropsychiatric Disorders and Mental Health, Anhui Province, China (G.J.J.); Department of Psychology, School of Education (G.J.J., H.H.M., W.L.), and Center for Cognition and Brain Disorders and the Affiliated Hospital (G.J.J., H.H.M., W.L.), Hangzhou Normal University, Hangzhou, China; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China (G.J.J., H.H.M., W.L.); Departments of Psychiatry (Y.Y.) and Neurology (Z.J.W., Y.L.T.), the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China; and Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China (W.L.)
| | - Wei Liao
- From the Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China (G.J.J.); Collaborative Innovation Centre of Neuropsychiatric Disorders and Mental Health, Anhui Province, China (G.J.J.); Department of Psychology, School of Education (G.J.J., H.H.M., W.L.), and Center for Cognition and Brain Disorders and the Affiliated Hospital (G.J.J., H.H.M., W.L.), Hangzhou Normal University, Hangzhou, China; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China (G.J.J., H.H.M., W.L.); Departments of Psychiatry (Y.Y.) and Neurology (Z.J.W., Y.L.T.), the Second Affiliated Hospital of Medial College, Zhejiang University, Zhejiang, China; and Center for Information in BioMedicine, Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China (W.L.)
| |
Collapse
|
39
|
Bharath RD, Sinha S, Panda R, Raghavendra K, George L, Chaitanya G, Gupta A, Satishchandra P. Seizure Frequency Can Alter Brain Connectivity: Evidence from Resting-State fMRI. AJNR Am J Neuroradiol 2015; 36:1890-8. [PMID: 26294642 DOI: 10.3174/ajnr.a4373] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 02/25/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The frequency of seizures is an important factor that can alter functional brain connectivity. Analysis of this factor in patients with epilepsy is complex because of disease- and medication-induced confounders. Because patients with hot-water epilepsy generally are not on long-term drug therapy, we used seed-based connectivity analysis in these patients to assess connectivity changes associated with seizure frequency without confounding from antiepileptic drugs. MATERIALS AND METHODS Resting-state fMRI data from 36 patients with hot-water epilepsy (18 with frequent seizures [>2 per month] and 18 with infrequent seizures [≤2 per month]) and 18 healthy age- and sex-matched controls were analyzed for seed-to-voxel connectivity by using 106 seeds. Voxel wise paired t-test analysis (P < .005, corrected for false-discovery rate) was used to identify significant intergroup differences between these groups. RESULTS Connectivity analysis revealed significant differences between the 2 groups (P < .001). Patients in the frequent-seizure group had increased connectivity within the medial temporal structures and widespread areas of poor connectivity, even involving the default mode network, in comparison with those in the infrequent-seizure group. Patients in the infrequent-seizure group had focal abnormalities with increased default mode network connectivity and decreased left entorhinal cortex connectivity. CONCLUSIONS The results of this study suggest that seizure frequency can alter functional brain connectivity, which can be visualized by using resting-state fMRI. Imaging features such as diffuse network abnormalities, involvement of the default mode network, and recruitment of medial temporal lobe structures were seen only in patients with frequent seizures. Future studies in more common epilepsy groups, however, will be required to further establish this finding.
Collapse
Affiliation(s)
- R D Bharath
- From the Departments of Neuroimaging and Interventional Radiology (R.D.B., R.P., L.G., A.G.) Advanced Brain Imaging Facility (R.D.B., R.P.), Cognitive Neuroscience Center, National Institute of Mental Health and Neuro Sciences, Bangalore, Karnataka, India
| | - S Sinha
- Neurology (S.S., K.R., G.C., P.S.)
| | - R Panda
- From the Departments of Neuroimaging and Interventional Radiology (R.D.B., R.P., L.G., A.G.) Advanced Brain Imaging Facility (R.D.B., R.P.), Cognitive Neuroscience Center, National Institute of Mental Health and Neuro Sciences, Bangalore, Karnataka, India
| | | | - L George
- From the Departments of Neuroimaging and Interventional Radiology (R.D.B., R.P., L.G., A.G.)
| | | | - A Gupta
- From the Departments of Neuroimaging and Interventional Radiology (R.D.B., R.P., L.G., A.G.)
| | | |
Collapse
|
40
|
Pan WJ, Billings JCW, Grooms JK, Shakil S, Keilholz SD. Considerations for resting state functional MRI and functional connectivity studies in rodents. Front Neurosci 2015; 9:269. [PMID: 26300718 PMCID: PMC4525377 DOI: 10.3389/fnins.2015.00269] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 07/16/2015] [Indexed: 12/31/2022] Open
Abstract
Resting state functional MRI (rs-fMRI) and functional connectivity mapping have become widely used tools in the human neuroimaging community and their use is rapidly spreading into the realm of rodent research as well. One of the many attractive features of rs-fMRI is that it is readily translatable from humans to animals and back again. Changes in functional connectivity observed in human studies can be followed by more invasive animal experiments to determine the neurophysiological basis for the alterations, while exploratory work in animal models can identify possible biomarkers for further investigation in human studies. These types of interwoven human and animal experiments have a potentially large impact on neuroscience and clinical practice. However, impediments exist to the optimal application of rs-fMRI in small animals, some similar to those encountered in humans and some quite different. In this review we identify the most prominent of these barriers, discuss differences between rs-fMRI in rodents and in humans, highlight best practices for animal studies, and review selected applications of rs-fMRI in rodents. Our goal is to facilitate the integration of human and animal work to the benefit of both fields.
Collapse
Affiliation(s)
- Wen-Ju Pan
- Department of Biomedical Engineering, Georgia Institute of Technology, Emory University Atlanta, GA, USA
| | | | - Joshua K Grooms
- Department of Biomedical Engineering, Georgia Institute of Technology, Emory University Atlanta, GA, USA
| | - Sadia Shakil
- School of Electrical and Computer Engineering, Georgia Institute of Technology Atlanta, GA, USA
| | - Shella D Keilholz
- Department of Biomedical Engineering, Georgia Institute of Technology, Emory University Atlanta, GA, USA ; Neuroscience Program, Emory University Atlanta, GA, USA
| |
Collapse
|
41
|
Hsiao FJ, Yu HY, Chen WT, Kwan SY, Chen C, Yen DJ, Yiu CH, Shih YH, Lin YY. Increased Intrinsic Connectivity of the Default Mode Network in Temporal Lobe Epilepsy: Evidence from Resting-State MEG Recordings. PLoS One 2015; 10:e0128787. [PMID: 26035750 PMCID: PMC4452781 DOI: 10.1371/journal.pone.0128787] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 04/30/2015] [Indexed: 11/23/2022] Open
Abstract
The electrophysiological signature of resting state oscillatory functional connectivity within the default mode network (DMN) during spike-free periods in temporal lobe epilepsy (TLE) remains unclear. Using magnetoencephalographic (MEG) recordings, this study investigated how the connectivity within the DMN was altered in TLE, and we examined the effect of lateralized TLE on functional connectivity. Sixteen medically intractable TLE patients and 22 controls participated in this study. Whole-scalp 306-channel MEG epochs without interictal spikes generated from both MEG and EEG data were analyzed using a minimum norm estimate (MNE) and source-based imaginary coherence analysis. With this processing, we obtained the cortical activation and functional connectivity within the DMN. The functional connectivity was increased between DMN and the right medial temporal (MT) region at the delta band and between DMN and the bilateral anterior cingulate cortex (ACC) regions at the theta band. The functional change was associated with the lateralization of TLE. The right TLE showed enhanced DMN connectivity with the right MT while the left TLE demonstrated increased DMN connectivity with the bilateral MT. There was no lateralization effect of TLE upon the DMN connectivity with ACC. These findings suggest that the resting-state functional connectivity within the DMN is reinforced in temporal lobe epilepsy during spike-free periods. Future studies are needed to examine if the altered functional connectivity can be used as a biomarker for treatment responses, cognitive dysfunction and prognosis in patients with TLE.
Collapse
Affiliation(s)
- Fu-Jung Hsiao
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan
- Department of Education and Research, Taipei City Hospital, Taipei, Taiwan
- Laboratory of Neurophysiology at Medical Research Division, Taipei Veterans General Hospital, Taipei, Taiwan
- * E-mail: (FJH); (YYL)
| | - Hsiang-Yu Yu
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Wei-Ta Chen
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Laboratory of Neurophysiology at Medical Research Division, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shang-Yeong Kwan
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chien Chen
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Der-Jen Yen
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chun-Hing Yiu
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yang-Hsin Shih
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurosurgery, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yung-Yang Lin
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Neurology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan
- Laboratory of Neurophysiology at Medical Research Division, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
- * E-mail: (FJH); (YYL)
| |
Collapse
|
42
|
Ji GJ, Zhang Z, Xu Q, Wang Z, Wang J, Jiao Q, Yang F, Tan Q, Chen G, Zang YF, Liao W, Lu G. Identifying Corticothalamic Network Epicenters in Patients with Idiopathic Generalized Epilepsy. AJNR Am J Neuroradiol 2015; 36:1494-500. [PMID: 25907518 DOI: 10.3174/ajnr.a4308] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/17/2015] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND PURPOSE Corticothalamic networks are considered core pathologic substrates for idiopathic generalized epilepsy; however, the predominant epileptogenic epicenters within these networks are still largely unknown. The current study aims to identify these epicenters by resting-state functional connectivity. MATERIALS AND METHODS To identify epicenters within the corticothalamic networks in idiopathic generalized epilepsy, we retrospectively studied a large cohort of patients with this condition (n = 97) along with healthy controls (n = 123) by resting-state functional MR imaging. The thalamus was functionally divided into subregions corresponding to distinct cortical lobes for 5 parallel corticothalamic networks. The functional connectivity between each voxel in the cortical lobe and the corresponding thalamic subregion was calculated, and functional connectivity strength was used to evaluate the interconnectivity of voxels in the cortex and thalamus. RESULTS The projection of 5 cortical lobes to the thalamus is consistent with previous histologic findings in humans. Compared with controls, patients with idiopathic generalized epilepsy showed increased functional connectivity strength in 4 corticothalamic networks: 1) the supplementary motor area, pulvinar, and ventral anterior nucleus in the prefrontal-thalamic network; 2) the premotor cortex and ventrolateral nucleus in motor/premotor-thalamic networks; 3) the visual cortex, posterior default mode regions, and pulvinar in parietal/occipital-thalamic networks; and 4) the middle temporal gyrus in the temporal-thalamic network. CONCLUSIONS Several key nodes were distinguished in 4 corticothalamic networks. The identification of these epicenters refines the corticothalamic network theory and provides insight into the pathophysiology of idiopathic generalized epilepsy.
Collapse
Affiliation(s)
- G-J Ji
- From the Center for Cognition and Brain Disorders and the Affiliated Hospital (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou Normal University, Hangzhou, China Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou, China
| | - Z Zhang
- Departments of Medical Imaging (Z.Z., Q.X., W.L., G.L.)
| | - Q Xu
- Departments of Medical Imaging (Z.Z., Q.X., W.L., G.L.)
| | - Z Wang
- Department of Medical Imaging (Z.W.), Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - J Wang
- From the Center for Cognition and Brain Disorders and the Affiliated Hospital (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou Normal University, Hangzhou, China Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou, China
| | - Q Jiao
- Department of Radiology (Q.J.), Taishan Medical University, Tai'an, China
| | | | - Q Tan
- Neurosurgery (Q.T.), Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | | | - Y-F Zang
- From the Center for Cognition and Brain Disorders and the Affiliated Hospital (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou Normal University, Hangzhou, China Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou, China
| | - W Liao
- From the Center for Cognition and Brain Disorders and the Affiliated Hospital (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou Normal University, Hangzhou, China Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments (G.-J.J., J.W., Y.-F.Z., W.L.), Hangzhou, China Departments of Medical Imaging (Z.Z., Q.X., W.L., G.L.)
| | - G Lu
- Departments of Medical Imaging (Z.Z., Q.X., W.L., G.L.)
| |
Collapse
|
43
|
Curwood EK, Pedersen M, Carney PW, Berg AT, Abbott DF, Jackson GD. Abnormal cortical thickness connectivity persists in childhood absence epilepsy. Ann Clin Transl Neurol 2015; 2:456-64. [PMID: 26000319 PMCID: PMC4435701 DOI: 10.1002/acn3.178] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/04/2015] [Indexed: 02/01/2023] Open
Abstract
Objective Childhood absence epilepsy (CAE) is a childhood-onset generalized epilepsy. Recent fMRI studies have suggested that frontal cortex activity occurs before thalamic involvement in epileptic discharges suggesting that frontal cortex may play an important role in childhood absence seizures. Neurocognitive deficits can persist after resolution of the epilepsy. We investigate whether structural connectivity changes are present in the brains of CAE patients in young adulthood. Methods Cortical thickness measurements were obtained for 30 subjects with CAE (mean age 21 ± 2 years) and 56 healthy controls (mean age 24 ± 4) and regressed for age, sex, and total intracranial volume (TIV). Structural connectivity was evaluated by measuring the correlation between average cortical thicknesses in 915 regions over the brain. Maps of connectivity strength were then obtained for both groups. Results When compared to controls, the CAE group shows overall increased “connectivity” with focal increased connection strength in anterior regions including; the anterior cingulate and the insula and superior temporal gyrus bilaterally; the right orbito-frontal and supramarginal regions; and the left entorhinal cortex. Decreased connection strength in the CAE group was found in the left occipital lobe, with a similar trend in right occipital lobe. Interpretation Brains in young adults whose CAE was resolved had abnormal structural connectivity. Our findings suggest that frontal regions correlate most with cortical thickness throughout the brain in CAE patients, whereas occipital regions correlate most in well matched normal controls. We interpret this as evidence of a developmental difference in CAE that emphasizes these frontal lobe regions, perhaps driven by frontal lobe epileptiform activity.
Collapse
Affiliation(s)
- Evan K Curwood
- The Florey Institute of Neuroscience and Mental Health Austin Campus, Heidelberg, Victoria, Australia
| | - Mangor Pedersen
- Florey Department of Neuroscience and Mental Health, The University of Melbourne Heidelberg, Victoria, Australia
| | - Patrick W Carney
- The Florey Institute of Neuroscience and Mental Health Austin Campus, Heidelberg, Victoria, Australia ; Department of Medicine, The University of Melbourne Parkville, Victoria, Australia
| | - Anne T Berg
- Epilepsy Center, Ann and Robert H. Lurie Children's Hospital of Chicago Chicago, Illinois
| | - David F Abbott
- The Florey Institute of Neuroscience and Mental Health Austin Campus, Heidelberg, Victoria, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne Heidelberg, Victoria, Australia ; Department of Medicine, The University of Melbourne Parkville, Victoria, Australia
| | - Graeme D Jackson
- The Florey Institute of Neuroscience and Mental Health Austin Campus, Heidelberg, Victoria, Australia ; Florey Department of Neuroscience and Mental Health, The University of Melbourne Heidelberg, Victoria, Australia ; Department of Medicine, The University of Melbourne Parkville, Victoria, Australia
| |
Collapse
|
44
|
Quantification of Interictal Neuromagnetic Activity in Absence Epilepsy with Accumulated Source Imaging. Brain Topogr 2014; 28:904-14. [PMID: 25359158 DOI: 10.1007/s10548-014-0411-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
Abstract
Aberrant brain activity in childhood absence epilepsy (CAE) during seizures has been well recognized as synchronous 3 Hz spike-and-wave discharges on electroencephalography. However, brain activity from low- to very high-frequency ranges in subjects with CAE between seizures (interictal) has rarely been studied. Using a high-sampling rate magnetoencephalography (MEG) system, we studied ten subjects with clinically diagnosed but untreated CAE in comparison with age- and gender-matched controls. MEG data were recorded from all subjects during the resting state. MEG sources were assessed with accumulated source imaging, a new method optimized for localizing and quantifying spontaneous brain activity. MEG data were analyzed in nine frequency bands: delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-30 Hz), low-gamma (30-55 Hz), high-gamma (65-90 Hz), ripple (90-200 Hz), high-frequency oscillation (HFO, 200-1,000 Hz), and very high-frequency oscillation (VHFO, 1,000-2,000 Hz). MEG source imaging revealed that subjects with CAE had higher odds of interictal brain activity in 200-1,000 and 1,000-2,000 Hz in the parieto-occipito-temporal junction and the medial frontal cortices as compared with controls. The strength of the interictal brain activity in these regions was significantly elevated in the frequency bands of 90-200, 200-1,000 and 1,000-2,000 Hz for subjects with CAE as compared with controls. The results indicate that CAE has significantly aberrant brain activity between seizures that can be noninvasively detected. The measurements of high-frequency neuromagnetic oscillations may open a new window for investigating the cerebral mechanisms of interictal abnormalities in CAE.
Collapse
|
45
|
Tenney JR, Fujiwara H, Horn PS, Vannest J, Xiang J, Glauser TA, Rose DF. Low- and high-frequency oscillations reveal distinct absence seizure networks. Ann Neurol 2014; 76:558-67. [PMID: 25042348 DOI: 10.1002/ana.24231] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The aim of this study was to determine the frequency-dependent, spatiotemporal involvement of corticothalamic networks to the generation of absence seizures. METHODS Magnetoencephalography recordings were obtained in 12 subjects (44 seizures) with untreated childhood absence seizures. Time-frequency analysis of each seizure was performed to determine bandwidths with significant power at ictal onset. Source localization was then completed to determine brain regions contributing to generalized spike and wave discharges seen on electroencephalogram. RESULTS Significant power in the time-frequency analysis was seen within 1 to 20Hz, 20 to 70Hz, and 70 to 150Hz bandwidths. Source localization revealed that sources localized to the frontal cortex similarly for the low- and gamma-frequency bandwidths, whereas at the low-frequency bandwidth (3-20Hz) significantly more sources localized to the parietal cortex (odds ratio [OR] = 16.7). Cortical sources within the high-frequency oscillation (HFO) bandwidth (70-150Hz) localized primarily to the frontal region compared to the parietal (OR = 7.32) or temporal (OR = 2.78) areas. INTERPRETATION Neuromagnetic activity within frontal and parietal cortical regions provides further confirmation of hemodynamic changes reported using functional magnetic resonance imaging that have been associated with absence seizures. The frequency-dependent nature of these networks has not previously been reported, and the presence of HFOs during absence seizures is a novel finding. Co-occurring frontal and parietal corticothalamic networks may interact to produce a pathological state that contributes to the generation of spike and wave discharges. The clinical and pathophysiological implications of HFOs within the frontal cortical region are unclear and should be further investigated.
Collapse
Affiliation(s)
- Jeffrey R Tenney
- Division of Neurology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH; Pediatric Neuroimaging Research Consortium, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH
| | | | | | | | | | | | | |
Collapse
|
46
|
Carney PW, Jackson GD. Insights into the mechanisms of absence seizure generation provided by EEG with functional MRI. Front Neurol 2014; 5:162. [PMID: 25225491 PMCID: PMC4150362 DOI: 10.3389/fneur.2014.00162] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 08/14/2014] [Indexed: 11/20/2022] Open
Abstract
Absence seizures (AS) are brief epileptic events characterized by loss of awareness with subtle motor features. They may be very frequent, and impact on attention, learning, and memory. A number of pathophysiological models have been developed to explain the mechanism of absence seizure generation, which relies heavily on observations from animal studies. Studying the structural and functional relationships between large-scale brain networks in humans is only practical with non-invasive whole brain techniques. EEG with functional MRI (EEG-fMRI) is one such technique that provides an opportunity to explore the interactions between brain structures involved in AS generation. A number of fMRI techniques including event-related analysis, time-course analysis, and functional connectivity (FC) have identified a common network of structures involved in AS. This network comprises the thalamus, midline, and lateral parietal cortex [the default mode network (DMN)], caudate nuclei, and the reticular structures of the pons. The main component displaying an increase in blood oxygen level dependent (BOLD) signal relative to the resting state, in group studies, is the thalamus while the most consistent cortical change is reduced BOLD signal in the DMN. Time-course analysis shows that, rather than some structures being activated or inactivated during AS, there appears to be increase in activity across components of the network preceding or following the electro-clinical onset of the seizure. The earliest change in BOLD signal occurs in the DMN, prior to the onset of epileptiform events. This region also shows altered FC in patients with AS. Hence, it appears that engagement of this network is central to AS. In this review, we will explore the insights of EEG-fMRI studies into the mechanisms of AS and consider how the DMN is likely to be the major large-scale brain network central to both seizure generation and seizure manifestations.
Collapse
Affiliation(s)
- Patrick W Carney
- The Florey Institute for Neuroscience and Mental Health , Heidelberg, VIC , Australia ; The University of Melbourne , Parkville, VIC , Australia ; Austin Health , Heidelberg, VIC , Australia
| | - Graeme D Jackson
- The Florey Institute for Neuroscience and Mental Health , Heidelberg, VIC , Australia ; The University of Melbourne , Parkville, VIC , Australia ; Austin Health , Heidelberg, VIC , Australia
| |
Collapse
|
47
|
Increased interhemispheric resting-state in idiopathic generalized epilepsy with generalized tonic-clonic seizures: a resting-state fMRI study. Epilepsy Res 2014; 108:1299-305. [PMID: 25043752 DOI: 10.1016/j.eplepsyres.2014.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 05/23/2014] [Accepted: 06/13/2014] [Indexed: 02/05/2023]
Abstract
PURPOSE The aim is to examine the resting state functional connectivity (RSFC) between the two hemispheres and its relationships with clinical characteristic in idiopathic generalized epilepsy with generalized tonic-clonic seizures only (IGE-GTCS) patients using a technique called "voxel-mirrored homotopic connectivity (VMHC)". METHODS The resting-state functional MRI (Rs-fMRI) was used to measure the RSFC in patients with IGE-GTC and age-gender matched healthy subjects. The between-group difference in interhemispheric RSFC was examined after the interhemispheric RSFC map was obtained by an automated VMHC approach. RESULTS Compared to the controls, the IGE-GTCS patients showed significant increases in VMHC in the bilateral anterior cingulate and medial prefrontal gyrus. No areas showed decreased VMHC in patients. Moreover, the VMHC in bilateral thalamus, orbital frontal cortex as well as cerebellum showed significant negative correlations with the illness duration. CONCLUSIONS The current findings provide preliminary evidence of increased interhemispheric RSFC in patients with IGE-GTCS during the interictal period. These VMHC deficits in these regions and the inverse relations between VMHC and clinical characteristic may play an important role in the pathophysiology of IGE-GTCS. Our study may contribute to the understanding of neuro-pathophysiological mechanism of epilepsy and psychosocial function impairments in patients with IGE-GTCS.
Collapse
|
48
|
Centeno M, Carmichael DW. Network Connectivity in Epilepsy: Resting State fMRI and EEG-fMRI Contributions. Front Neurol 2014; 5:93. [PMID: 25071695 PMCID: PMC4081640 DOI: 10.3389/fneur.2014.00093] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 05/25/2014] [Indexed: 12/18/2022] Open
Abstract
There is a growing body of evidence pointing toward large-scale networks underlying the core phenomena in epilepsy, from seizure generation to cognitive dysfunction or response to treatment. The investigation of networks in epilepsy has become a key concept to unlock a deeper understanding of the disease. Functional imaging can provide valuable information to characterize network dysfunction; in particular resting state fMRI (RS-fMRI), which is increasingly being applied to study brain networks in a number of diseases. In patients with epilepsy, network connectivity derived from RS-fMRI has found connectivity abnormalities in a number of networks; these include the epileptogenic, cognitive and sensory processing networks. However, in majority of these studies, the effect of epileptic transients in the connectivity of networks has been neglected. EEG–fMRI has frequently shown networks related to epileptic transients that in many cases are concordant with the abnormalities shown in RS studies. This points toward a relevant role of epileptic transients in the network abnormalities detected in RS-fMRI studies. In this review, we summarize the network abnormalities reported by these two techniques side by side, provide evidence of their overlapping findings, and discuss their significance in the context of the methodology of each technique. A number of clinically relevant factors that have been associated with connectivity changes are in turn associated with changes in the frequency of epileptic transients. These factors include different aspects of epilepsy ranging from treatment effects, cognitive processes, or transition between different alertness states (i.e., awake–sleep transition). For RS-fMRI to become a more effective tool to investigate clinically relevant aspects of epilepsy it is necessary to understand connectivity changes associated with epileptic transients, those associated with other clinically relevant factors and the interaction between them, which represents a gap in the current literature. We propose a framework for the investigation of network connectivity in patients with epilepsy that can integrate epileptic processes that occur across different time scales such as epileptic transients and disease duration and the implications of this approach are discussed.
Collapse
Affiliation(s)
- Maria Centeno
- Imaging and Biophysics Unit, Institute of Child Health, University College London , London , UK ; Epilepsy Unit, Great Ormond Street Hospital , London , UK
| | - David W Carmichael
- Imaging and Biophysics Unit, Institute of Child Health, University College London , London , UK ; Epilepsy Unit, Great Ormond Street Hospital , London , UK
| |
Collapse
|
49
|
Structural and functional correlates of epileptogenesis - does gender matter? Neurobiol Dis 2014; 70:69-73. [PMID: 24943053 DOI: 10.1016/j.nbd.2014.05.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/15/2014] [Accepted: 05/22/2014] [Indexed: 01/10/2023] Open
Abstract
In the majority of neuropsychiatric conditions, marked gender-based differences have been found in the epidemiology, clinical manifestations, and therapy of disease. One possible reason is that sex differences in cerebral morphology, structural and functional connections, render men and women differentially vulnerable to various disease processes. The present review addresses this issue with respect to the functional and structural correlates to some forms of epilepsy.
Collapse
|
50
|
Mishra AM, Bai X, Sanganahalli BG, Waxman SG, Shatillo O, Grohn O, Hyder F, Pitkänen A, Blumenfeld H. Decreased resting functional connectivity after traumatic brain injury in the rat. PLoS One 2014; 9:e95280. [PMID: 24748279 PMCID: PMC3991600 DOI: 10.1371/journal.pone.0095280] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 03/25/2014] [Indexed: 01/19/2023] Open
Abstract
Traumatic brain injury (TBI) contributes to about 10% of acquired epilepsy. Even though the mechanisms of post-traumatic epileptogenesis are poorly known, a disruption of neuronal networks predisposing to altered neuronal synchrony remains a viable candidate mechanism. We tested a hypothesis that resting state BOLD-fMRI functional connectivity can reveal network abnormalities in brain regions that are connected to the lesioned cortex, and that these changes associate with functional impairment, particularly epileptogenesis. TBI was induced using lateral fluid-percussion injury in seven adult male Sprague-Dawley rats followed by functional imaging at 9.4T 4 months later. As controls we used six sham-operated animals that underwent all surgical operations but were not injured. Electroencephalogram (EEG)-functional magnetic resonance imaging (fMRI) was performed to measure resting functional connectivity. A week after functional imaging, rats were implanted with bipolar skull electrodes. After recovery, rats underwent pentyleneterazol (PTZ) seizure-susceptibility test under EEG. For image analysis, four pairs of regions of interests were analyzed in each hemisphere: ipsilateral and contralateral frontal and parietal cortex, hippocampus, and thalamus. High-pass and low-pass filters were applied to functional imaging data. Group statistics comparing injured and sham-operated rats and correlations over time between each region were calculated. In the end, rats were perfused for histology. None of the rats had epileptiform discharges during functional imaging. PTZ-test, however revealed increased seizure susceptibility in injured rats as compared to controls. Group statistics revealed decreased connectivity between the ipsilateral and contralateral parietal cortex and between the parietal cortex and hippocampus on the side of injury as compared to sham-operated animals. Injured animals also had abnormal negative connectivity between the ipsilateral and contralateral parietal cortex and other regions. Our data provide the first evidence on abnormal functional connectivity after experimental TBI assessed with resting state BOLD-fMRI.
Collapse
Affiliation(s)
- Asht Mangal Mishra
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Core Center for Quantitative Neuroscience with Magnetic Resonance, Yale University, New Haven, Connecticut, United States of America
| | - Xiaoxiao Bai
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Basavaraju G. Sanganahalli
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Core Center for Quantitative Neuroscience with Magnetic Resonance, Yale University, New Haven, Connecticut, United States of America
| | - Stephen G. Waxman
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Center for Neuroscience and Regeneration Research, West Haven, Connecticut, United States of America
| | - Olena Shatillo
- Department of Neurobiology, A. I. Virtanen Institute of Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Olli Grohn
- Biomedical NMR research group, Biomedical Imaging Unit, University of Eastern Finland, Kuopio, Finland
| | - Fahmeed Hyder
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Core Center for Quantitative Neuroscience with Magnetic Resonance, Yale University, New Haven, Connecticut, United States of America
| | - Asla Pitkänen
- Department of Neurobiology, A. I. Virtanen Institute of Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - Hal Blumenfeld
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Core Center for Quantitative Neuroscience with Magnetic Resonance, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
| |
Collapse
|