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Pérez P, Manasova D, Hermann B, Raimondo F, Rohaut B, Bekinschtein TA, Naccache L, Arzi A, Sitt JD. Content-state dimensions characterize different types of neuronal markers of consciousness. Neurosci Conscious 2024; 2024:niae027. [PMID: 39011546 PMCID: PMC11246840 DOI: 10.1093/nc/niae027] [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: 11/08/2023] [Revised: 05/30/2024] [Accepted: 06/08/2024] [Indexed: 07/17/2024] Open
Abstract
Identifying the neuronal markers of consciousness is key to supporting the different scientific theories of consciousness. Neuronal markers of consciousness can be defined to reflect either the brain signatures underlying specific conscious content or those supporting different states of consciousness, two aspects traditionally studied separately. In this paper, we introduce a framework to characterize markers according to their dynamics in both the "state" and "content" dimensions. The 2D space is defined by the marker's capacity to distinguish the conscious states from non-conscious states (on the x-axis) and the content (e.g. perceived versus unperceived or different levels of cognitive processing on the y-axis). According to the sign of the x- and y-axis, markers are separated into four quadrants in terms of how they distinguish the state and content dimensions. We implement the framework using three types of electroencephalography markers: markers of connectivity, markers of complexity, and spectral summaries. The neuronal markers of state are represented by the level of consciousness in (i) healthy participants during a nap and (ii) patients with disorders of consciousness. On the other hand, the neuronal markers of content are represented by (i) the conscious content in healthy participants' perception task using a visual awareness paradigm and (ii) conscious processing of hierarchical regularities using an auditory local-global paradigm. In both cases, we see separate clusters of markers with correlated and anticorrelated dynamics, shedding light on the complex relationship between the state and content of consciousness and emphasizing the importance of considering them simultaneously. This work presents an innovative framework for studying consciousness by examining neuronal markers in a 2D space, providing a valuable resource for future research, with potential applications using diverse experimental paradigms, neural recording techniques, and modeling investigations.
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Affiliation(s)
- Pauline Pérez
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
- Hospice Civils de Lyon—HCL, Département anesthésie-réanimation, Hôpital Edouard Herriot
- Neuro ICU, DMU Neurosciences, AP-HP, Hôpital de la Pitié Salpêtrière, Paris 75013, France
| | - Dragana Manasova
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
- Université Paris Cité, Paris 75006, France
| | - Bertrand Hermann
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
- Université Paris Cité, Paris 75006, France
- Medical Intensive Care Unit, HEGP Hôpital, Assistance Publique—Hôpitaux de Paris-Centre (APHP-Centre), Paris 75015, France
| | - Federico Raimondo
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
- Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Research Centre Jülich, Jülich 52428, Germany
- Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Dusseldorf 40225, Germany
| | - Benjamin Rohaut
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
- Neuro ICU, DMU Neurosciences, AP-HP, Hôpital de la Pitié Salpêtrière, Paris 75013, France
| | - Tristán A Bekinschtein
- Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Lionel Naccache
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
- AP-HP, Hôpital Pitié-Salpêtrière, Service de Neurophysiologie Clinique, Paris 75013, France
| | - Anat Arzi
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
- Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
- Department of Medical Neurobiology, Institute for Medical Research Israel Canada and Department of Cognitive and Brain Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jacobo D Sitt
- Institut du Cerveau - Paris Brain Institute, Inserm, CNRS, Sorbonne Université, Paris 75013, France
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Matringe E, Vidal JR, Perrone-Bertolotti M, Vercueil L. The epileptic blip syndrome. Epilepsy Behav Rep 2024; 27:100691. [PMID: 39050405 PMCID: PMC11268190 DOI: 10.1016/j.ebr.2024.100691] [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: 05/01/2024] [Revised: 06/25/2024] [Accepted: 06/25/2024] [Indexed: 07/27/2024] Open
Abstract
We report on the case of an adolescent with juvenile myoclonic epilepsy exhibiting compulsory sporadic voluntary movement. These movements entailed the deliberate act of touching her forehead with her hand and were triggered by a short and indefinable cephalic sensation. Upon inquiry regarding the nature of this movement, the patient reported a sudden perception of a peculiar event localized "inside her head". In the course of a prolonged video-electroencephalographic recording, it appeared that the movements consistently followed the occurrence of diffuse Generalized Spike-and-Wave Bursts (GSWBs), lasting one to three seconds. This observation suggests that the impact of the GSWBs on the patient's stream of consciousness could be detected by the patient herself, who attributed it to an internal sensation, like a "blip on a screen". This clinical observation echoes the "blip syndrome", as described by the neurologist James W. Lance thirty years ago. These findings give some support that "blips" could be of an epileptic origin and lend weight to the notion that some patients could perceive their own EEG discharges. Moreover, this observation should be added to the perennial debate on the cognitive impact of intercritical discharges.
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Affiliation(s)
- Edgar Matringe
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, LPNC, 38000 Grenoble, France
| | - Juan R. Vidal
- Lyon Catholic University, UR CONFLUENCE : Sciences et Humanités (EA 1598), 69002 Lyon, France
| | | | - Laurent Vercueil
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, LPNC, 38000 Grenoble, France
- Service des Explorations Fonctionnelles du Système Nerveux, CHU Grenoble Alpes, 38000 Grenoble, France
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Groulx-Boivin E, Bouchet T, Myers KA. Understanding of Consciousness in Absence Seizures: A Literature Review. Neuropsychiatr Dis Treat 2024; 20:1345-1353. [PMID: 38947367 PMCID: PMC11212660 DOI: 10.2147/ndt.s391052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 06/14/2024] [Indexed: 07/02/2024] Open
Abstract
Absence seizures are classically associated with behavioral arrest and transient deficits in consciousness, yet substantial variability exists in the severity of the impairment. Despite several decades of research on the topic, the pathophysiology of absence seizures and the mechanisms underlying behavioral impairment remain unclear. Several rationales have been proposed including widespread cortical deactivation, reduced perception of external stimuli, and transient suspension of the default mode network, among others. This review aims to summarize the current knowledge on the neural correlates of impaired consciousness in absence seizures. We review evidence from studies using animal models of absence epilepsy, electroencephalography, functional magnetic resonance imaging, magnetoencephalography, positron emission tomography, and single photon emission computed tomography.
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Affiliation(s)
- Emilie Groulx-Boivin
- Department of Neurology and Neurosurgery, Montreal Children’s Hospital, McGill University, Montreal, Quebec, Canada
- Department of Pediatrics, Montreal Children’s Hospital, McGill University, Montreal, Quebec, Canada
| | - Tasha Bouchet
- Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Kenneth A Myers
- Department of Neurology and Neurosurgery, Montreal Children’s Hospital, McGill University, Montreal, Quebec, Canada
- Department of Pediatrics, Montreal Children’s Hospital, McGill University, Montreal, Quebec, Canada
- Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
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Mahon S. Variation and convergence in the morpho-functional properties of the mammalian neocortex. Front Syst Neurosci 2024; 18:1413780. [PMID: 38966330 PMCID: PMC11222651 DOI: 10.3389/fnsys.2024.1413780] [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: 04/07/2024] [Accepted: 06/03/2024] [Indexed: 07/06/2024] Open
Abstract
Man's natural inclination to classify and hierarchize the living world has prompted neurophysiologists to explore possible differences in brain organisation between mammals, with the aim of understanding the diversity of their behavioural repertoires. But what really distinguishes the human brain from that of a platypus, an opossum or a rodent? In this review, we compare the structural and electrical properties of neocortical neurons in the main mammalian radiations and examine their impact on the functioning of the networks they form. We discuss variations in overall brain size, number of neurons, length of their dendritic trees and density of spines, acknowledging their increase in humans as in most large-brained species. Our comparative analysis also highlights a remarkable consistency, particularly pronounced in marsupial and placental mammals, in the cell typology, intrinsic and synaptic electrical properties of pyramidal neuron subtypes, and in their organisation into functional circuits. These shared cellular and network characteristics contribute to the emergence of strikingly similar large-scale physiological and pathological brain dynamics across a wide range of species. These findings support the existence of a core set of neural principles and processes conserved throughout mammalian evolution, from which a number of species-specific adaptations appear, likely allowing distinct functional needs to be met in a variety of environmental contexts.
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Affiliation(s)
- Séverine Mahon
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, Paris, France
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Daquin G, Bonini F. The landscape of drug resistant absence seizures in adolescents and adults: Pathophysiology, electroclinical spectrum and treatment options. Rev Neurol (Paris) 2024; 180:256-270. [PMID: 38413268 DOI: 10.1016/j.neurol.2023.11.010] [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: 10/02/2023] [Revised: 11/17/2023] [Accepted: 11/21/2023] [Indexed: 02/29/2024]
Abstract
The persistence of typical absence seizures (AS) in adolescence and adulthood may reduce the quality of life of patients with genetic generalized epilepsies (GGEs). The prevalence of drug resistant AS is probably underestimated in this patient population, and treatment options are relatively scarce. Similarly, atypical absence seizures in developmental and epileptic encephalopathies (DEEs) may be unrecognized, and often persist into adulthood despite improvement of more severe seizures. These two seemingly distant conditions, represented by typical AS in GGE and atypical AS in DEE, share at least partially overlapping pathophysiological and genetic mechanisms, which may be the target of drug and neurostimulation therapies. In addition, some patients with drug-resistant typical AS may present electroclinical features that lie in between the two extremes represented by these generalized forms of epilepsy.
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Affiliation(s)
- G Daquin
- Epileptology and Cerebral Rythmology, AP-HM, Timone hospital, Marseille, France
| | - F Bonini
- Epileptology and Cerebral Rythmology, AP-HM, Timone hospital, Marseille, France; Aix Marseille Univ, Inserm, INS, Inst Neurosci Syst, Marseille, France.
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Li Y, Gao J, Yang Y, Zhuang Y, Kang Q, Li X, Tian M, Lv H, He J. Temporal and spatial variability of dynamic microstate brain network in disorders of consciousness. CNS Neurosci Ther 2024; 30:e14641. [PMID: 38385681 PMCID: PMC10883110 DOI: 10.1111/cns.14641] [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: 10/10/2023] [Revised: 01/17/2024] [Accepted: 02/01/2024] [Indexed: 02/23/2024] Open
Abstract
BACKGROUND Accurately diagnosing patients with the vegetative state (VS) and the minimally conscious state (MCS) reached a misdiagnosis of approximately 40%. METHODS A method combined microstate and dynamic functional connectivity (dFC) to study the spatiotemporal variability of the brain in disorders of consciousness (DOC) patients was proposed. Resting-state EEG data were obtained from 16 patients with MCS and 16 patients with VS. Mutual information (MI) was used to assess the EEG connectivity in each microstate. MI-based features with statistical differences were selected as the total feature subset (TFS), then the TFS was utilized to feature selection and fed into the classifier, obtaining the optimal feature subsets (OFS) in each microstate. Subsequently, an OFS-based MI functional connectivity network (MIFCN) was constructed in the cortex. RESULTS The group-average MI connectivity matrix focused on all channels revealed that all five microstates exhibited stronger information interaction in the MCS when comparing with the VS. While OFS-based MIFCN, which only focused on a few channels, revealed greater MI flow in VS patients than in MCS patients under microstates A, B, C, and E, except for microstate D. Additionally, the average classification accuracy of OFS in the five microstates was 96.2%. CONCLUSION Constructing features based on microstates to distinguish between two categories of DOC patients had effectiveness.
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Affiliation(s)
- Yaqian Li
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, College of Biomedical EngineeringSouth‐Central Minzu UniversityWuhanChina
| | - Junfeng Gao
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, College of Biomedical EngineeringSouth‐Central Minzu UniversityWuhanChina
| | - Ying Yang
- College of Foreign LanguagesWuhan University of TechnologyWuhanChina
| | - Yvtong Zhuang
- Department of Neurosurgery, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
| | - Qianruo Kang
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, College of Biomedical EngineeringSouth‐Central Minzu UniversityWuhanChina
| | - Xiang Li
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, College of Biomedical EngineeringSouth‐Central Minzu UniversityWuhanChina
| | - Min Tian
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, College of Biomedical EngineeringSouth‐Central Minzu UniversityWuhanChina
| | - Haoan Lv
- Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, College of Biomedical EngineeringSouth‐Central Minzu UniversityWuhanChina
| | - Jianghong He
- Department of Neurosurgery, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
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Sitnikova E. Behavioral and Cognitive Comorbidities in Genetic Rat Models of Absence Epilepsy (Focusing on GAERS and WAG/Rij Rats). Biomedicines 2024; 12:122. [PMID: 38255227 PMCID: PMC10812980 DOI: 10.3390/biomedicines12010122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/02/2024] [Accepted: 01/05/2024] [Indexed: 01/24/2024] Open
Abstract
Absence epilepsy is a non-convulsive type of epilepsy characterized by the sudden loss of awareness. It is associated with thalamo-cortical impairment, which may cause neuropsychiatric and neurocognitive problems. Rats with spontaneous absence-like seizures are widely used as in vivo genetic models for absence epilepsy; they display behavioral and cognitive problems similar to epilepsy in humans, such as genetic absence epilepsy rats from Strasbourg (GAERS) and Wistar Albino rats from Rijswijk (WAG/Rij). Depression- and anxiety-like behaviors were apparent in GAERS, but no anxiety and depression-like symptoms were found in WAG/Rij rats. Deficits in executive functions and memory impairment in WAG/Rij rats, i.e., cognitive comorbidities, were linked to the severity of epilepsy. Wistar rats can develop spontaneous seizures in adulthood, so caution is advised when using them as a control epileptic strain. This review discusses challenges in the field, such as putative high emotionality in genetically prone rats, sex differences in the expression of cognitive comorbidities, and predictors of cognitive problems or biomarkers of cognitive comorbidities in absence epilepsy, as well as the concept of "the cognitive thalamus". The current knowledge of behavioral and cognitive comorbidities in drug-naive rats with spontaneous absence epilepsy is beneficial for understanding the pathophysiology of absence epilepsy, and for finding new treatment strategies.
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Affiliation(s)
- Evgenia Sitnikova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5A Butlerova St., Moscow 117485, Russia
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Edlow BL, Boerwinkle VL, Annen J, Boly M, Gosseries O, Laureys S, Mukherjee P, Puybasset L, Stevens RD, Threlkeld ZD, Newcombe VFJ, Fernandez-Espejo D. Common Data Elements for Disorders of Consciousness: Recommendations from the Working Group on Neuroimaging. Neurocrit Care 2023; 39:611-617. [PMID: 37552410 DOI: 10.1007/s12028-023-01794-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 06/22/2023] [Indexed: 08/09/2023]
Abstract
BACKGROUND Over the past 5 decades, advances in neuroimaging have yielded insights into the pathophysiologic mechanisms that cause disorders of consciousness (DoC) in patients with severe brain injuries. Structural, functional, metabolic, and perfusion imaging studies have revealed specific neuroanatomic regions, such as the brainstem tegmentum, thalamus, posterior cingulate cortex, medial prefrontal cortex, and occipital cortex, where lesions correlate with the current or future state of consciousness. Advanced imaging modalities, such as diffusion tensor imaging, resting-state functional magnetic resonance imaging (fMRI), and task-based fMRI, have been used to improve the accuracy of diagnosis and long-term prognosis, culminating in the endorsement of fMRI for the clinical evaluation of patients with DoC in the 2018 US (task-based fMRI) and 2020 European (task-based and resting-state fMRI) guidelines. As diverse neuroimaging techniques are increasingly used for patients with DoC in research and clinical settings, the need for a standardized approach to reporting results is clear. The success of future multicenter collaborations and international trials fundamentally depends on the implementation of a shared nomenclature and infrastructure. METHODS To address this need, the Neurocritical Care Society's Curing Coma Campaign convened an international panel of DoC neuroimaging experts to propose common data elements (CDEs) for data collection and reporting in this field. RESULTS We report the recommendations of this CDE development panel and disseminate CDEs to be used in neuroimaging studies of patients with DoC. CONCLUSIONS These CDEs will support progress in the field of DoC neuroimaging and facilitate international collaboration.
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Affiliation(s)
- Brian L Edlow
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
| | - Varina L Boerwinkle
- Clinical Resting-State Functional Magnetic Resonance Imaging Laboratory and Service, Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Jitka Annen
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium
- Centre de Cerveau2, University Hospital of Liège, Liège, Belgium
| | - Melanie Boly
- Department of Neurology, University of Wisconsin, Madison, WI, USA
- Department of Psychiatry, Wisconsin Institute for Sleep and Consciousness, University of Wisconsin, Madison, WI, USA
| | - Olivia Gosseries
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium
- Centre de Cerveau2, University Hospital of Liège, Liège, Belgium
| | - Steven Laureys
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium
- Centre de Cerveau2, University Hospital of Liège, Liège, Belgium
- CERVO Research Institute, Laval University, Quebec, Canada
| | - Pratik Mukherjee
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
| | - Louis Puybasset
- Department of Anesthesiology and Intensive Care, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Robert D Stevens
- Departments of Anesthesiology and Critical Care Medicine, Neurology, Radiology, and Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zachary D Threlkeld
- Department of Neurology, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Davinia Fernandez-Espejo
- School of Psychology and Centre for Human Brain Health, University of Birmingham, Birmingham, UK
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Sun F, Wang S, Wang Y, Sun J, Li Y, Li Y, Xu Y, Wang X. Differences in generation and maintenance between ictal and interictal generalized spike-and-wave discharges in childhood absence epilepsy: A magnetoencephalography study. Epilepsy Behav 2023; 148:109440. [PMID: 37748416 DOI: 10.1016/j.yebeh.2023.109440] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/05/2023] [Accepted: 09/05/2023] [Indexed: 09/27/2023]
Abstract
PURPOSE Childhood absence epilepsy (CAE) is characterized by impaired consciousness and distinct electroencephalogram (EEG) patterns. However, interictal epileptiform discharges (IEDs) do not lead to noticeable symptoms. This study examines the disparity between ictal and interictal generalized spike-and-wave discharges (GSWDs) to determine the mechanisms behind CAE and consciousness. METHODS We enrolled 24 patients with ictal and interictal GSWDs in the study. The magnetoencephalography (MEG) data were recorded before and during GSWDs at a sampling rate of 6000 Hz and analyzed across six frequency bands. The absolute and relative spectral power were estimated with the Minimum Norm Estimate (MNE) combined with the Welch technique. All the statistical analyses were performed using paired-sample tests. RESULTS During GSWDs, the right lateral occipital cortex indicated a significant difference in the theta band (5-7 Hz) with stronger power (P = 0.027). The interictal group possessed stronger spectral power in the delta band (P < 0.01) and weaker power in the alpha band (P < 0.01) as early as 10 s before GSWDs in absolute and relative spectral power. Additionally, the ictal group revealed enhanced spectral power inside the occipital cortex in the alpha band and stronger spectral power in the right frontal regions within beta (15-29 Hz), gamma 1 (30-59 Hz), and gamma 2 (60-90 Hz) bands. CONCLUSIONS GSWDs seem to change gradually, with local neural activity changing even 10 s before discharge. During GSWDs, visual afferent stimulus insensitivity could be related to the impaired response state in CAE. The inhibitory signal in the low-frequency band can shorten GSWD duration, thereby achieving seizure control through inhibitory effect strengthening.
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Affiliation(s)
- Fangling Sun
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Siyi Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yingfan Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Jintao Sun
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yihan Li
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yanzhang Li
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yue Xu
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaoshan Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China.
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Caciagli L, Ratcliffe C, Xiao F, van Graan LA, Trimmel K, Vollmar C, Centeno M, Duncan JS, Thompson PJ, Baxendale S, Koepp MJ, Wandschneider B. Cognitive phenotype of juvenile absence epilepsy: An investigation of patients and unaffected siblings. Epilepsia 2023; 64:2792-2805. [PMID: 37475704 PMCID: PMC10952612 DOI: 10.1111/epi.17719] [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: 11/24/2022] [Revised: 07/13/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Abstract
OBJECTIVE The cognitive profile of juvenile absence epilepsy (JAE) remains largely uncharacterized. This study aimed to: (1) elucidate the neuropsychological profile of JAE; (2) identify familial cognitive traits by investigating unaffected JAE siblings; (3) establish the clinical meaningfulness of JAE-associated cognitive traits; (4) determine whether cognitive traits across the idiopathic generalized epilepsy (IGE) spectrum are shared or syndrome-specific, by comparing JAE to juvenile myoclonic epilepsy (JME); and (5) identify relationships between cognitive abilities and clinical characteristics. METHODS We investigated 123 participants-23 patients with JAE, 16 unaffected siblings of JAE patients, 45 healthy controls, and 39 patients with JME-who underwent a comprehensive neuropsychological test battery including measures within four cognitive domains: attention/psychomotor speed, language, memory, and executive function. We correlated clinical measures with cognitive performance data to decode effects of age at onset and duration of epilepsy. RESULTS Cognitive performance in individuals with JAE was reduced compared to controls across attention/psychomotor speed, language, and executive function domains; those with ongoing seizures additionally showed lower memory scores. Patients with JAE and their unaffected siblings had similar language impairment compared to controls. Individuals with JME had worse response inhibition than those with JAE. Across all patients, those with older age at onset had better attention/psychomotor speed performance. SIGNIFICANCE JAE is associated with wide-ranging cognitive difficulties that encompass domains reliant on frontal lobe processing, including language, attention, and executive function. JAE siblings share impairment with patients on linguistic measures, indicative of a familial trait. Executive function subdomains may be differentially affected across the IGE spectrum. Cognitive abilities are detrimentally modulated by an early age at seizure onset.
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Affiliation(s)
- Lorenzo Caciagli
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Department of Neurology, Inselspital, Sleep‐Wake‐Epilepsy‐Center, Bern University HospitalUniversity of BernBernSwitzerland
| | - Corey Ratcliffe
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Department of Pharmacology and Therapeutics, Institute of Systems, Molecular, and Integrative BiologyUniversity of LiverpoolLiverpoolUK
- Department of Neuroimaging and Interventional RadiologyNational Institute of Mental Health and NeurosciencesBangaloreIndia
| | - Fenglai Xiao
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Louis A. van Graan
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Karin Trimmel
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Department of NeurologyMedical University of ViennaViennaAustria
| | - Christian Vollmar
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Department of NeurologyLudwig‐Maximilians‐UniversitätMunichGermany
| | - Maria Centeno
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
- Epilepsy Unit, Department of NeurologyHospital Clínic de BarcelonaBarcelonaSpain
| | - John S. Duncan
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Pamela J. Thompson
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Sallie Baxendale
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Matthias J. Koepp
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
| | - Britta Wandschneider
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- MRI UnitEpilepsy SocietyBuckinghamshireUK
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Sun F, Wang Y, Li Y, Li Y, Wang S, Xu F, Wang X. Variation in functional networks between clinical and subclinical discharges in childhood absence epilepsy: A multi-frequency MEG study. Seizure 2023; 111:109-121. [PMID: 37598560 DOI: 10.1016/j.seizure.2023.08.005] [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: 04/24/2023] [Revised: 08/06/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
OBJECTIVE Two types of spike-and-wave discharges (SWDs) exist in childhood absence epilepsy (CAE): clinical discharges are prolonged and manifest primarily as impaired consciousness, whereas subclinical discharges are brief with few objectively visible symptoms. This study aimed to compare neural functional network and default mode network (DMN) activity between clinical and subclinical discharges to better understand the underlying mechanism of CAE. METHODS Using magnetoencephalography (MEG) data from 21 patients, we obtained 25 segments each of clinical discharges and subclinical discharges. Amplitude envelope correlation analysis was used to construct functional networks and graph theory was used to calculate network topological data. We then compared differences in functional connectivity within the DMN between clinical and subclinical discharges. All statistical comparisons were performed using paired-sample tests. RESULTS Compared to subclinical discharges, the functional network of clinical discharges exhibited higher synchronization - particularly in the parahippocampal gyrus - as early as 10 s before the seizure. Additionally, the functional network of clinical SWDs presented an anterior shift of key nodes in the alpha frequency band. Regarding clinical discharge progression, there were gradual increases in the parameter node strengths (S), clustering coefficients (C), and global efficiency (E) of the functional networks, while the path lengths (L) decreased. These changes were most prominent at the onset of discharges and followed by some recovery in the high-frequency bands, but no significant change in the low-frequency bands. Furthermore, connections within the DMN during the discharge period were significantly stronger for clinical discharge compared to subclinical discharges. CONCLUSIONS These findings suggest that a more regular network before abnormal discharges in clinical discharges contributes to SWD explosion and that the parahippocampal gyrus plays an important role in maintaining oscillations. An absence seizure is a gradual process and the emergence of SWDs may be accompanied by initiation of inhibitory mechanisms. Enhanced functional connectivity among DMN brain regions may indicate that patients have entered a state of introspection, and functional abnormalities in the parahippocampal gyrus may be associated with patients' transient memory loss.
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Affiliation(s)
- Fangling Sun
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yingfan Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yihan Li
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yanzhang Li
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Siyi Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Fengyuan Xu
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaoshan Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China.
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12
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Krestel H, Schreier DR, Sakiri E, von Allmen A, Abukhadra Y, Nirkko A, Steinlin M, Rosenow F, Markhus R, Schneider G, Jagella C, Mathis J, Blumenfeld H. Predictive Power of Interictal Epileptiform Discharges in Fitness-to-Drive Evaluation. Neurology 2023; 101:e866-e878. [PMID: 37414567 PMCID: PMC10501101 DOI: 10.1212/wnl.0000000000207531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 05/04/2023] [Indexed: 07/08/2023] Open
Abstract
BACKGROUND AND OBJECTIVES This study aimed to evaluate and predict the effects of interictal epileptiform discharges (IEDs) on driving ability using simple reaction tests and a driving simulator. METHODS Patients with various epilepsies were evaluated with simultaneous EEGs during their response to visual stimuli in a single-flash test, a car-driving video game, and a realistic driving simulator. Reaction times (RTs) and missed reactions or crashes (miss/crash) during normal EEG and IEDs were measured. IEDs, as considered in this study, were a series of epileptiform potentials (>1 potential) and were classified as generalized typical, generalized atypical, or focal. RT and miss/crash in relation to IED type, duration, and test type were analyzed. RT prolongation, miss/crash probability, and odds ratio (OR) of miss/crash due to IEDs were calculated. RESULTS Generalized typical IEDs prolonged RT by 164 ms, compared with generalized atypical IEDs (77.0 ms) and focal IEDs (48.0 ms) (p < 0.01). Generalized typical IEDs had a session miss/crash probability of 14.7% compared with a zero median for focal and generalized atypical IEDs (p < 0.01). Long repetitive bursts of focal IEDs lasting >2 seconds had a 2.6% miss/crash probabilityIED. Cumulated miss/crash probability could be predicted from RT prolongation: 90.3 ms yielded a 20% miss/crash probability. All tests were nonsuperior to each other in detecting miss/crash probabilitiesIED (zero median for all 3 tests) or RT prolongations (flash test: 56.4 ms, car-driving video game: 75.5 ms, simulator 86.6 ms). IEDs increased the OR of miss/crash in the simulator by 4.9-fold compared with normal EEG. A table of expected RT prolongations and miss/crash probabilities for IEDs of a given type and duration was created. DISCUSSION IED-associated miss/crash probability and RT prolongation were comparably well detected by all tests. Long focal IED bursts carry a low risk, while generalized typical IEDs are the primary cause of miss/crash. We propose a cumulative 20% miss/crash risk at an RT prolongation of 90.3 ms as a clinically relevant IED effect. The IED-associated OR in the simulator approximates the effects of sleepiness or low blood alcohol level while driving on real roads. A decision aid for fitness-to-drive evaluation was created by providing the expected RT prolongations and misses/crashes when IEDs of a certain type and duration are detected in routine EEG.
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Affiliation(s)
- Heinz Krestel
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway.
| | - David R Schreier
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Elmaze Sakiri
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Andreas von Allmen
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Yasmina Abukhadra
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Arto Nirkko
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Maja Steinlin
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Felix Rosenow
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Rune Markhus
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Gaby Schneider
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Caroline Jagella
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Johannes Mathis
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
| | - Hal Blumenfeld
- From the Departments of Neurology (H.K., Y.A., C.J., H.B.), Neuroscience (H.B.), and Neurosurgery (H.B.), Yale School of Medicine, New Haven, CT; Epilepsy Center Frankfurt Rhine-Main (H.K., F.R.), University Hospital Frankfurt, Center for Personalized Translational Epilepsy Research (CePTER), and Institute of Mathematics (G.S.), Department of Computer Science and Mathematics, Goethe University, Frankfurt, Germany; Department of Neurology (D.R.S., A.N., J.M.); Departments of Cardiology (E.S.) and Pediatric Neurology (M.S.), Bern University Hospital and University of Bern; Neurocenter Lucerne (A.N.), Switzerland; and National Centre for Epilepsy (R.M.), Division of Clinical Neuroscience Oslo University Hospital, Norway
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13
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Gallagher MJ. Neuronal Physiology of Generalized Seizures: The 4 Horsemen of Absence Epilepsy. Epilepsy Curr 2023; 23:262-264. [PMID: 37662465 PMCID: PMC10470100 DOI: 10.1177/15357597231172322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023] Open
Abstract
Decreased but Diverse Activity of Cortical and Thalamic Neurons in Consciousness-Impairing Rodent Absence Seizures McCafferty C, Gruenbaum BF, Tung R, Li JJ, Zheng X, Salvino P, Vincent P, Kratochvil Z, Ryu JH, Khalaf A, Swift K, Akbari R, Islam W, Antwi P, Johnson EA, Vitkovskiy P, Sampognaro J, Freedman IG, Kundishora A, Depaulis A, David F, Crunelli V, Sanganahalli BG, Herman P, Hyder F, Blumenfeld H. Nat Commun . 2023;14(1):117. doi:10.1038/s41467-022-35535-4 Absence seizures are brief episodes of impaired consciousness, behavioral arrest, and unresponsiveness, with yet-unknown neuronal mechanisms. Here we report that an awake female rat model recapitulates the behavioral, electroencephalographic, and cortical functional magnetic resonance imaging characteristics of human absence seizures. Neuronally, seizures feature overall decreased but rhythmic firing of neurons in cortex and thalamus. Individual cortical and thalamic neurons express one of four distinct patterns of seizure-associated activity, one of which causes a transient initial peak in overall firing at seizure onset, and another which drives sustained decreases in overall firing. 40-60 s before seizure onset there begins a decline in low frequency electroencephalographic activity, neuronal firing, and behavior, but an increase in higher frequency electroencephalography and rhythmicity of neuronal firing. Our findings demonstrate that prolonged brain state changes precede consciousness-impairing seizures, and that during seizures distinct functional groups of cortical and thalamic neurons produce an overall transient firing increase followed by a sustained firing decrease, and increased rhythmicity.
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14
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Crunelli V, David F, Morais TP, Lorincz ML. HCN channels and absence seizures. Neurobiol Dis 2023; 181:106107. [PMID: 37001612 DOI: 10.1016/j.nbd.2023.106107] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/20/2023] [Accepted: 03/25/2023] [Indexed: 03/31/2023] Open
Abstract
Hyperpolarization-activation cyclic nucleotide-gated (HCN) channels were for the first time implicated in absence seizures (ASs) when an abnormal Ih (the current generated by these channels) was reported in neocortical layer 5 neurons of a mouse model. Genetic studies of large cohorts of children with Childhood Absence Epilepsy (where ASs are the only clinical symptom) have identified only 3 variants in HCN1 (one of the genes that code for the 4 HCN channel isoforms, HCN1-4), with one (R590Q) mutation leading to loss-of-function. Due to the multi-faceted effects that HCN channels exert on cellular excitability and neuronal network dynamics as well as their modulation by environmental factors, it has been difficult to identify the detailed mechanism by which different HCN isoforms modulate ASs. In this review, we systematically and critically analyze evidence from established AS models and normal non-epileptic animals with area- and time-selective ablation of HCN1, HCN2 and HCN4. Notably, whereas knockout of rat HCN1 and mouse HCN2 leads to the expression of ASs, the pharmacological block of all HCN channel isoforms abolishes genetically determined ASs. These seemingly contradictory results could be reconciled by taking into account the well-known opposite effects of Ih on cellular excitability and network function. Whereas existing evidence from mouse and rat AS models indicates that pan-HCN blockers may provide a novel approach for the treatment of human ASs, the development of HCN isoform-selective drugs would greatly contribute to current research on the role for these channels in ASs generation and maintenance as well as offer new potential clinical applications.
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Affiliation(s)
- Vincenzo Crunelli
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK.
| | - Francois David
- Integrative Neuroscience and Cognition Center, Paris University, Paris, France
| | - Tatiana P Morais
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, Malta University, Msida, Malta
| | - Magor L Lorincz
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK; Department of Physiology, Szeged University, Szeged, Hungary.
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15
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McCafferty C, Gruenbaum BF, Tung R, Li JJ, Zheng X, Salvino P, Vincent P, Kratochvil Z, Ryu JH, Khalaf A, Swift K, Akbari R, Islam W, Antwi P, Johnson EA, Vitkovskiy P, Sampognaro J, Freedman IG, Kundishora A, Depaulis A, David F, Crunelli V, Sanganahalli BG, Herman P, Hyder F, Blumenfeld H. Decreased but diverse activity of cortical and thalamic neurons in consciousness-impairing rodent absence seizures. Nat Commun 2023; 14:117. [PMID: 36627270 PMCID: PMC9832004 DOI: 10.1038/s41467-022-35535-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 12/08/2022] [Indexed: 01/12/2023] Open
Abstract
Absence seizures are brief episodes of impaired consciousness, behavioral arrest, and unresponsiveness, with yet-unknown neuronal mechanisms. Here we report that an awake female rat model recapitulates the behavioral, electroencephalographic, and cortical functional magnetic resonance imaging characteristics of human absence seizures. Neuronally, seizures feature overall decreased but rhythmic firing of neurons in cortex and thalamus. Individual cortical and thalamic neurons express one of four distinct patterns of seizure-associated activity, one of which causes a transient initial peak in overall firing at seizure onset, and another which drives sustained decreases in overall firing. 40-60 s before seizure onset there begins a decline in low frequency electroencephalographic activity, neuronal firing, and behavior, but an increase in higher frequency electroencephalography and rhythmicity of neuronal firing. Our findings demonstrate that prolonged brain state changes precede consciousness-impairing seizures, and that during seizures distinct functional groups of cortical and thalamic neurons produce an overall transient firing increase followed by a sustained firing decrease, and increased rhythmicity.
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Affiliation(s)
- Cian McCafferty
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
| | | | - Renee Tung
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Jing-Jing Li
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Xinyuan Zheng
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Peter Salvino
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Peter Vincent
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Zachary Kratochvil
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Jun Hwan Ryu
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Aya Khalaf
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Kohl Swift
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Rashid Akbari
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Wasif Islam
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Prince Antwi
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Emily A Johnson
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Petr Vitkovskiy
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - James Sampognaro
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Isaac G Freedman
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Adam Kundishora
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Antoine Depaulis
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000, Grenoble, France
| | - François David
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK
| | - Vincenzo Crunelli
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK
| | - Basavaraju G Sanganahalli
- Magnetic Resonance Research Center, Yale University, New Haven, CT, 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, 06520, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA
| | - Peter Herman
- Magnetic Resonance Research Center, Yale University, New Haven, CT, 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, 06520, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA
| | - Fahmeed Hyder
- Magnetic Resonance Research Center, Yale University, New Haven, CT, 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, 06520, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale School of Medicine, New Haven, CT, 06520, USA.
- Magnetic Resonance Research Center, Yale University, New Haven, CT, 06520, USA.
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, 06520, USA.
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, 06520, USA.
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16
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Kumar A, Lyzhko E, Hamid L, Srivastav A, Stephani U, Japaridze N. Neuronal networks underlying ictal and subclinical discharges in childhood absence epilepsy. J Neurol 2023; 270:1402-1415. [PMID: 36370186 PMCID: PMC9971098 DOI: 10.1007/s00415-022-11462-8] [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: 09/08/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 11/13/2022]
Abstract
Childhood absence epilepsy (CAE), involves 3 Hz generalized spikes and waves discharges (GSWDs) on the electroencephalogram (EEG), associated with ictal discharges (seizures) with clinical symptoms and impairment of consciousness and subclinical discharges without any objective clinical symptoms or impairment of consciousness. This study aims to comparatively characterize neuronal networks underlying absence seizures and subclinical discharges, using source localization and functional connectivity (FC), to better understand the pathophysiological mechanism of these discharges. Routine EEG data from 12 CAE patients, consisting of 45 ictal and 42 subclinical discharges were selected. Source localization was performed using the exact low-resolution electromagnetic tomography (eLORETA) algorithm, followed by FC based on the imaginary part of coherency. FC based on the thalamus as the seed of interest showed significant differences between ictal and subclinical GSWDs (p < 0.05). For delta (1-3 Hz) and alpha bands (8-12 Hz), the thalamus displayed stronger connectivity towards other brain regions for ictal GSWDs as compared to subclinical GSWDs. For delta band, the thalamus was strongly connected to the posterior cingulate cortex (PCC), precuneus, angular gyrus, supramarginal gyrus, parietal superior, and occipital mid-region for ictal GSWDs. The strong connections of the thalamus with other brain regions that are important for consciousness, and with components of the default mode network (DMN) suggest the severe impairment of consciousness in ictal GSWDs. However, for subclinical discharges, weaker connectivity between the thalamus and these brain regions may suggest the prevention of impairment of consciousness. This may benefit future therapeutic targets and improve the management of CAE patients.
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Affiliation(s)
- Ami Kumar
- Department of Neuropediatrics, Children's Hospital, University Medical Center Schleswig-Holstein, University of Kiel, Kiel, Germany. .,Faculty of Mathematics and Natural Sciences, University of Kiel, Kiel, Germany. .,Department of Neurology, Columbia University Irving Medical Center, New York, USA.
| | - Ekaterina Lyzhko
- Department of Neuropediatrics, Children’s Hospital, University Medical Center Schleswig-Holstein, University of Kiel, Kiel, Germany
| | - Laith Hamid
- Institute of Medical Psychology and Medical Sociology, University of Kiel, Kiel, Germany ,Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Anand Srivastav
- Faculty of Mathematics and Natural Sciences, University of Kiel, Kiel, Germany
| | - Ulrich Stephani
- Department of Neuropediatrics, Children’s Hospital, University Medical Center Schleswig-Holstein, University of Kiel, Kiel, Germany
| | - Natia Japaridze
- Department of Neuropediatrics, Children’s Hospital, University Medical Center Schleswig-Holstein, University of Kiel, Kiel, Germany
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Kronemer SI, Aksen M, Ding JZ, Ryu JH, Xin Q, Ding Z, Prince JS, Kwon H, Khalaf A, Forman S, Jin DS, Wang K, Chen K, Hu C, Agarwal A, Saberski E, Wafa SMA, Morgan OP, Wu J, Christison-Lagay KL, Hasulak N, Morrell M, Urban A, Todd Constable R, Pitts M, Mark Richardson R, Crowley MJ, Blumenfeld H. Human visual consciousness involves large scale cortical and subcortical networks independent of task report and eye movement activity. Nat Commun 2022; 13:7342. [PMID: 36446792 PMCID: PMC9707162 DOI: 10.1038/s41467-022-35117-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 11/17/2022] [Indexed: 11/30/2022] Open
Abstract
The full neural circuits of conscious perception remain unknown. Using a visual perception task, we directly recorded a subcortical thalamic awareness potential (TAP). We also developed a unique paradigm to classify perceived versus not perceived stimuli using eye measurements to remove confounding signals related to reporting on conscious experiences. Using fMRI, we discovered three major brain networks driving conscious visual perception independent of report: first, increases in signal detection regions in visual, fusiform cortex, and frontal eye fields; and in arousal/salience networks involving midbrain, thalamus, nucleus accumbens, anterior cingulate, and anterior insula; second, increases in frontoparietal attention and executive control networks and in the cerebellum; finally, decreases in the default mode network. These results were largely maintained after excluding eye movement-based fMRI changes. Our findings provide evidence that the neurophysiology of consciousness is complex even without overt report, involving multiple cortical and subcortical networks overlapping in space and time.
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Affiliation(s)
- Sharif I Kronemer
- Department of Neurology, Yale University, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Mark Aksen
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Julia Z Ding
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Jun Hwan Ryu
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Qilong Xin
- Department of Neurology, Yale University, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Zhaoxiong Ding
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Jacob S Prince
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Hunki Kwon
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Aya Khalaf
- Department of Neurology, Yale University, New Haven, CT, USA
- Biomedical Engineering and Systems, Faculty of Engineering, Cairo University, Giza, Egypt
| | - Sarit Forman
- Department of Neurology, Yale University, New Haven, CT, USA
| | - David S Jin
- Department of Neurology, Yale University, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Kevin Wang
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Kaylie Chen
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Claire Hu
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Akshar Agarwal
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Erik Saberski
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Syed Mohammad Adil Wafa
- Department of Neurology, Yale University, New Haven, CT, USA
- Child Study Center, Yale University, New Haven, CT, USA
- Division of Psychology and Language Sciences, University College London, London, UK
| | - Owen P Morgan
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Jia Wu
- Child Study Center, Yale University, New Haven, CT, USA
| | | | | | | | | | - R Todd Constable
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
- Department of Neurosurgery, Yale University, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | | | - R Mark Richardson
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | | | - Hal Blumenfeld
- Department of Neurology, Yale University, New Haven, CT, USA.
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA.
- Department of Neurosurgery, Yale University, New Haven, CT, USA.
- Department of Neuroscience, Yale University, New Haven, CT, USA.
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18
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Li J, Feng P, Zhao L, Chen J, Du M, Song J, Wu Y. Transition behavior of the seizure dynamics modulated by the astrocyte inositol triphosphate noise. CHAOS (WOODBURY, N.Y.) 2022; 32:113121. [PMID: 36456345 DOI: 10.1063/5.0124123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
Epilepsy is a neurological disorder with recurrent seizures, which convey complex dynamical characteristics including chaos and randomness. Until now, the underlying mechanism has not been fully elucidated, especially the bistable property beneath the epileptic random induction phenomena in certain conditions. Inspired by the recent finding that astrocyte GTPase-activating protein (G-protein)-coupled receptors could be involved in stochastic epileptic seizures, we proposed a neuron-astrocyte network model, incorporating the noise of the astrocytic second messenger, inositol triphosphate (IP3) that is modulated by G-protein-coupled receptor activation. Based on this model, we have statistically analyzed the transitions of epileptic seizures by performing repeatable simulation trials. Our simulation results show that the increase in the IP3 noise intensity induces depolarization-block epileptic seizures together with an increase in neuronal firing frequency, consistent with corresponding experiments. Meanwhile, the bistable states of the seizure dynamics were present under certain noise intensities, during which the neuronal firing pattern switches between regular sparse spiking and epileptic seizure states. This random presence of epileptic seizures is absent when the noise intensity continues to increase, accompanying with an increase in the epileptic depolarization block duration. The simulation results also shed light on the fact that calcium signals in astrocytes play significant roles in the pattern formations of the epileptic seizure. Our results provide a potential pathway for understanding the epileptic randomness in certain conditions.
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Affiliation(s)
- Jiajia Li
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Peihua Feng
- State Key Laboratory for Strength and Vibration of Mechanical Structures, National Demonstration Center for Experimental Mechanics Education, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Liang Zhao
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Junying Chen
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Mengmeng Du
- School of Mathematics and Data Science, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Jian Song
- Department of Neurosurgery, Wuhan General Hospital of PLA, Wuhan 430070, China
| | - Ying Wu
- State Key Laboratory for Strength and Vibration of Mechanical Structures, National Demonstration Center for Experimental Mechanics Education, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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Springer M, Khalaf A, Vincent P, Ryu JH, Abukhadra Y, Beniczky S, Glauser T, Krestel H, Blumenfeld H. A machine-learning approach for predicting impaired consciousness in absence epilepsy. Ann Clin Transl Neurol 2022; 9:1538-1550. [PMID: 36114696 PMCID: PMC9539371 DOI: 10.1002/acn3.51647] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/10/2022] Open
Abstract
Behavior during 3-4 Hz spike-wave discharges (SWDs) in absence epilepsy can vary from obvious behavioral arrest to no detectible deficits. Knowing if behavior is impaired is crucial for clinical care but may be difficult to determine without specialized behavioral testing, often inaccessible in practice. We aimed to develop a pure electroencephalography (EEG)-based machine-learning method to predict SWD-related behavioral impairment. Our classification goals were 100% predictive value, with no behaviorally impaired SWDs misclassified as spared; and maximal sensitivity. First, using labeled data with known behavior (130 SWDs in 34 patients), we extracted EEG time, frequency domain, and common spatial pattern features and applied support vector machines and linear discriminant analysis to classify SWDs as spared or impaired. We evaluated 32 classification models, optimized with 10-fold cross-validation. We then generalized these models to unlabeled data (220 SWDs in 41 patients), where behavior during individual SWDs was not known, but observers reported the presence of clinical seizures. For labeled data, the best classifier achieved 100% spared predictive value and 93% sensitivity. The best classifier on the unlabeled data achieved 100% spared predictive value, but with a lower sensitivity of 35%, corresponding to a conservative classification of 8 patients out of 23 as free of clinical seizures. Our findings demonstrate the feasibility of machine learning to predict impaired behavior during SWDs based on EEG features. With additional validation and optimization in a larger data sample, applications may include EEG-based prediction of driving safety, treatment adjustment, and insight into mechanisms of impaired consciousness in absence seizures.
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Affiliation(s)
- Max Springer
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
| | - Aya Khalaf
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
- Biomedical Engineering and Systems, Faculty of EngineeringCairo UniversityGizaEgypt
| | - Peter Vincent
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
| | - Jun Hwan Ryu
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
| | - Yasmina Abukhadra
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
| | - Sandor Beniczky
- Department of Clinical NeuorophysiologyDanish Epilepsy CenterDianalundDenmark
- Aarhus University HospitalAarhusDenmark
| | - Tracy Glauser
- Division of NeurologyCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
- Department of PediatricsUniversity of Cincinnati College of MedicineCincinnatiOhioUSA
| | - Heinz Krestel
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
- Epilepsy CenterUniversity Hospital FrankfurtFrankfurtGermany
- Center for Personalized Translational Epilepsy Research (CePTER)Goethe UniversityFrankfurtGermany
| | - Hal Blumenfeld
- Department of NeurologyYale University School of MedicineNew HavenConnecticutUSA
- Department of NeuroscienceYale University School of MedicineNew HavenConnecticutUSA
- Department of NeurosurgeryYale University School of MedicineNew HavenConnecticutUSA
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20
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Scholly J, Gras A, Guye M, Bilger M, Valenti Hirsch MP, Hirsch E, Timofeev A, Vidailhet P, Bénar CG, Bartolomei F. Connectivity Alterations in Emotional and Cognitive Networks During a Manic State Induced by Direct Electrical Stimulation. Brain Topogr 2022; 35:627-635. [PMID: 36071370 DOI: 10.1007/s10548-022-00913-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 08/27/2022] [Indexed: 11/28/2022]
Abstract
Mania is characterized by affective and cognitive alterations, with heightened external and self-awareness that are opposite to the alteration of awareness during epileptic seizures. Electrical stimulations carried out routinely during stereotactic intracerebral EEG (SEEG) recordings for presurgical evaluation of epilepsy may represent a unique opportunity to study the pathophysiology of such complex emotional-behavioral phenomenon, particularly difficult to reproduce in experimental setting. We investigated SEEG signals-based functional connectivity between different brain regions involved in emotions and in consciousness processing during a manic state induced by electrical stimulation in a patient with drug-resistant focal epilepsy. The stimulation inducing manic state and an asymptomatic stimulation of the same site, as well as a seizure with alteration of awareness (AOA) were analyzed. Functional connectivity analysis was performed by measuring interdependencies (nonlinear regression analysis based on the h2 coefficient) between broadband SEEG signals and within typical sub-bands, before and after stimulation, or before and during the seizure with AOA, respectively. Stimulation of the right lateral prefrontal cortex induced a manic state lasting several hours. Its onset was associated with significant increase of broadband-signal functional coupling between the right hemispheric limbic nodes, the temporal pole and the claustrum, whereas significant decorrelation between the right lateral prefrontal and the anterior cingulate cortex was observed in theta-band. In contrast, ictal alteration of awareness was associated with increased broadband and sub-bands synchronization within and between the internal and external awareness networks, including the anterior and middle cingulate, the mesial and lateral prefrontal, the inferior parietal and the temporopolar cortex. Our data suggest the existence of network- and frequency-specific functional connectivity patterns during manic state. A transient desynchronization of theta activity between the external and internal awareness network hubs is likely to increase awareness, with potential therapeutic effect.
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Affiliation(s)
- Julia Scholly
- Service d'Epileptologie et de Rythmololgie Cérébrale, Hôpital Timone, AP-HM, Marseille, France. .,Aix Marseille Univ, CNRS, CRMBM, Marseille, France. .,Service d'Epileptologie et Rythmologie Cérébrale, Hôpital Timone, AP-HM, 264 Rue St Pierre, 13005, Marseille, France.
| | - Adrien Gras
- Consultation-Liaison Psychiatry Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Maxime Guye
- Service d'Epileptologie et de Rythmololgie Cérébrale, Hôpital Timone, AP-HM, Marseille, France.,Aix Marseille Univ, CNRS, CRMBM, Marseille, France
| | - Mathias Bilger
- Medical and Surgical Epilepsy Unit, University Hospital of Strasbourg, Strasbourg, France
| | | | - Edouard Hirsch
- Medical and Surgical Epilepsy Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Alexander Timofeev
- Medical and Surgical Epilepsy Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Pierre Vidailhet
- Consultation-Liaison Psychiatry Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Christian G Bénar
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Fabrice Bartolomei
- Service d'Epileptologie et de Rythmololgie Cérébrale, Hôpital Timone, AP-HM, Marseille, France.,Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
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21
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Gallagher MJ. Oh, What a Tangled Web Epilepsy Genes May Weave. Epilepsy Curr 2022; 22:309-311. [PMID: 36285202 PMCID: PMC9549235 DOI: 10.1177/15357597221112799] [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] [Indexed: 11/16/2022] Open
Abstract
Aberrant Neuronal Connectivity in the Cortex Drives Generation of Seizures in
Rat Absence Epilepsy Studer F, Jarre G, Pouyatos B, et al. Brain 2022;145(6):1978-1991.
doi:10.1093/brain/awab438. Absence epilepsy belongs to genetic epilepsies and is characterized by recurrent
generalized seizures that are concomitant with alterations of consciousness and
associated with cognitive comorbidities. Little is known about the mechanisms leading
to occurrence of epileptic seizures (i.e., epileptogenesis) and, in particular, it
remains an open question whether neuronal hypersynchronization, a key feature in
seizure initiation, could result from aberrant structural connectivity within neuronal
networks endowing them with epileptic properties. In the present study, we addressed
this question using a genetic model of absence epilepsy in the rat where seizures
initiate in the whisker primary somatosensory cortex. We hypothesized that alterations
in structural connectivity of neuronal networks within wS1 contribute to pathological
neuronal synchronization responsible for seizures. First, we used rabies
virus-mediated retrograde synaptic tracing and evidenced that cortical neurons located
in both upper- and deep-layers of whisker primary somatosensory cortex displayed
aberrant and significantly increased connectivity the genetic model of absence
epilepsy, as highlighted by a higher number of presynaptic partners. Next, we showed
at the functional level that disrupting these aberrant whisker primary somatosensory
cortex neuronal networks with synchrotron X-ray-mediated cortical microtransections
drastically decreased both whisker primary somatosensory cortex neuron synchronization
and seizure power, as revealed by in vivo local field potential recordings with
multichannel probes. Taken together, our data provide for the first time strong
evidence that increased structural connectivity patterns of cortical neurons represent
critical pathological substrates for increased neuronal synchronization and generation
of absence seizures.
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Affiliation(s)
- Martin J. Gallagher
- Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN, USA
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22
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Beniczky S, Tatum WO, Blumenfeld H, Stefan H, Mani J, Maillard L, Fahoum F, Vinayan KP, Mayor LC, Vlachou M, Seeck M, Ryvlin P, Kahane P. Seizure semiology: ILAE glossary of terms and their significance. Epileptic Disord 2022; 24:447-495. [PMID: 35770761 DOI: 10.1684/epd.2022.1430] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 02/19/2022] [Indexed: 11/17/2022]
Abstract
This educational topical review and Task Force report aims to address learning objectives of the International League Against Epilepsy (ILAE) curriculum. We sought to extract detailed features involving semiology from video recordings and interpret semiological signs and symptoms that reflect the likely localization for focal seizures in patients with epilepsy. This glossary was developed by a working group of the ILAE Commission on Diagnostic Methods incorporating the EEG Task Force. This paper identifies commonly used terms to describe seizure semiology, provides definitions, signs and symptoms, and summarizes their clinical value in localizing and lateralizing focal seizures based on consensus in the published literature. Video-EEG examples are included to illustrate important features of semiology in patients with epilepsy.
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23
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Li Z, Huang J, Wei W, Jiang S, Liu H, Luo H, Ruan J. EEG Oscillatory Networks in Peri-Ictal Period of Absence Epilepsy. Front Neurol 2022; 13:825225. [PMID: 35547382 PMCID: PMC9081722 DOI: 10.3389/fneur.2022.825225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 03/28/2022] [Indexed: 11/15/2022] Open
Abstract
Objective To investigate the dynamical brain network changes before and after an absence seizure episode in absence epilepsy (AE). Methods 21 AE patients with a current high frequency of seizures and 21 sex- and age-matched health control (HC) who reported no history of neurological or psychiatric disorders and visited the hospital for routine physical examinations were included. Each included subject underwent a 2-h and 19-channel video EEG examination. For AE patients, five epochs of 10-s EEG data in inter-ictal, pre-ictal, and post-ictal states were collected. For the HC group, five 10-s resting-state EEG epochs were extracted. Functional independent components analysis (ICA) was carried out using the LORETA KEY tool. Results Compared with the resting-state EEG data of the HC group, the EEG data from AE patients during inter-ictal periods showed decreased alpha oscillations in regions involving the superior frontal gyrus (SFG) (BA11). From inter-ictal to pre-ictal, SFG (BA10) showed maximum decreased delta oscillations. Additionally, from pre-ictal to post-ictal, superior temporal gyrus (STG) (BA 22) presented maximum increased neural activity in the alpha band. Moreover, compared with inter-ictal EEG, post-ictal EEG showed significantly decreased theta activity in SFG (BA8). Conclusion The changes in SFG alpha oscillations are the key brain network differences between inter-ictal EEG of AE patients and resting-state EEG of HCs. The brain networks of EEG oscillatory during peri-ictal episodes are mainly involving SFG and STG. Our study suggests that altered EEG brain networks dynamics exist between inter-ictal EEG of AE patients and resting-state EEG of HCs and between pre- and post-ictal EEG in AE patients.
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Affiliation(s)
- Zhiye Li
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Laboratory of Neurological Diseases and Brain Function, Luzhou, China
| | - Jialing Huang
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Laboratory of Neurological Diseases and Brain Function, Luzhou, China
| | - Wei Wei
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Laboratory of Neurological Diseases and Brain Function, Luzhou, China
| | - Sili Jiang
- Department of Neurology, Suining Central Hospital, Suining, China
| | - Hong Liu
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Laboratory of Neurological Diseases and Brain Function, Luzhou, China
| | - Hua Luo
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Laboratory of Neurological Diseases and Brain Function, Luzhou, China
| | - Jianghai Ruan
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Laboratory of Neurological Diseases and Brain Function, Luzhou, China
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24
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Chu C, Li N, Zhong R, Zhao D, Lin W. Efficacy of Phenobarbital and Prognosis Predictors in Women With Epilepsy From Rural Northeast China: A 10-Year Follow-Up Study. Front Neurol 2022; 13:838098. [PMID: 35250838 PMCID: PMC8889069 DOI: 10.3389/fneur.2022.838098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/24/2022] [Indexed: 01/03/2023] Open
Abstract
Objective To investigate the efficacy of phenobarbital (PB), factors associated with it, reasons for early treatment termination, and mortality rates in adult women living in rural Northeast China. Methods A prospective study was conducted in seven counties of Jilin Province from 2010 to 2020. Adult women diagnosed with convulsive epilepsy were recruited into the study and baseline demographics recorded upon enrollment. Seizure frequency, prescribed drug dose, and adverse reactions were monitored monthly by door-to-door survey or telephone interview. Results A total of 1,333 women were included in the study. During the follow-up period, 169 participants (12.7%) were lost to follow-up, and 100 of them (7.5%) died. The percentage of seizure-free participants was 45.3% in the first year, 74.6% in the third year, and 96.6% in the 10th year. A higher baseline seizure frequency (OR = 1.005, 95% CI: 1.002–1.009), more frequent loss-of-consciousness seizures (OR = 1.620, 95% CI: 1.318–1.990), a higher daily dose of PB in the first year (OR = 1.018, 95% CI: 1.014–1.022), a younger age at onset (OR = 0.990, 95% CI: 0.982–0.998), and more severe drowsiness (OR = 1.727, 95% CI: 1.374–2.173) were associated with an increased risk of seizures in the first year, and the higher baseline seizure frequency was still associated with the occurrence of seizures in the third (OR = 1.007, 95% CI: 1.004–1.010) and fifth year (OR = 1.005, 95% CI: 1.002–1.008). Age at enrollment (HR = 0.983, 95% CI: 0.971–0.994) was the only factor that correlated with withdrawal from the study and with the death of the participant during the follow up period, but the correlation in each case was in opposite directions. Significance PB has high effectiveness, retention rate, mild side effects, and tolerability when used as a treatment for epilepsy in women from rural areas. Baseline seizure frequency is an important predictor of prognosis regardless of treatment duration. PB is still a valuable tool for the management of epilepsy in adult women from poverty-stricken areas.
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Affiliation(s)
- Chaojia Chu
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Nan Li
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Rui Zhong
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Danyang Zhao
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Weihong Lin
- Department of Neurology, Neuroscience Center, The First Hospital of Jilin University, Changchun, China
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25
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Association of network connectivity via resting state functional MRI with consciousness, mortality, and outcomes in neonatal acute brain injury. Neuroimage Clin 2022; 34:102962. [PMID: 35152054 PMCID: PMC8851268 DOI: 10.1016/j.nicl.2022.102962] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 01/07/2023]
Abstract
Basal ganglia and seizure onset zone networks were associated with motor outcomes. Broad language/cognitive region networks were associated with developmental delay. Discharge with mortality was linked to default mode and language/cognitive networks. Exams were not linked to networks after multiple testing corrections. Lack of detection of all studied networks only occurred in those who did not survive.
Background An accurate and comprehensive test of integrated brain network function is needed for neonates during the acute brain injury period to inform on morbidity. This retrospective cohort study assessed whether integrated brain network function acquired by resting state functional MRI during the acute period in neonates with brain injury, is associated with acute exam, neonatal mortality, and 6-month outcomes. Methods Study subjects included 40 consecutive neonates with resting state functional MRI acquired within 31 days after suspected brain insult from March 2018 to July 2019 at Phoenix Children’s Hospital. Acute-period exam and test results were assigned ordinal scores based on severity as documented by respective treating specialists. Analyses (Fisher exact, Wilcoxon-rank sum test, ordinal/multinomial logistic regression) examined association of resting state networks with demographics, presentation, neurological exam, electroencephalogram, anatomical MRI, magnetic resonance spectroscopy, passive task functional MRI, and outcomes of discharge condition, outpatient development, motor tone, seizure, and mortality. Results Subjects had a mean (standard deviation) gestational age of 37.8 (2.6) weeks, a majority were male (63%), with a diagnosis of hypoxic ischemic encephalopathy (68%). Findings at birth included mild distress (48%), moderately abnormal neurological exam (33%), and consciousness characterized as awake but irritable (40%). Significant associations after multiple testing corrections were detected for resting state networks: basal ganglia with outpatient developmental delay (odds ratio [OR], 14.5; 99.4% confidence interval [CI], 2.00–105; P < .001) and motor tone/weakness (OR, 9.98; 99.4% CI, 1.72–57.9; P < .001); language/frontoparietal network with discharge condition (OR, 5.13; 99.4% CI, 1.22–21.5; P = .002) and outpatient developmental delay (OR, 4.77; 99.4% CI, 1.21–18.7; P=.002); default mode network with discharge condition (OR, 3.72; 99.4% CI, 1.01–13.78; P=.006) and neurological exam (P = .002 (FE); OR, 11.8; 99.4% CI, 0.73–191; P = .01 (OLR)); and seizure onset zone with motor tone/weakness (OR, 3.31; 99.4% CI, 1.08–10.1; P=.003). Resting state networks were not detected in three neonates, who died prior to discharge. Conclusions This study provides level 3 evidence (OCEBM Levels of Evidence Working Group) demonstrating that in neonatal acute brain injury, the degree of abnormality of resting state networks is associated with acute exam and outcomes. Total lack of brain network detection was only found in patients who did not survive.
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26
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Genetic generalized epilepsies in adults - challenging assumptions and dogmas. Nat Rev Neurol 2022; 18:71-83. [PMID: 34837042 DOI: 10.1038/s41582-021-00583-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2021] [Indexed: 01/16/2023]
Abstract
Genetic generalized epilepsy (GGE) syndromes start during childhood or adolescence, and four commonly persist into adulthood, making up 15-20% of all cases of epilepsy in adults. These four GGE syndromes are childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and epilepsy with generalized tonic-clonic seizures alone. However, in ~20% of patients with GGE, characteristics of more than one syndrome are present. Novel insights into the genetic aetiology, comorbidities and prognosis of the GGE syndromes have emerged and challenge traditional concepts about these conditions. Evidence has shown that the mode of inheritance in GGE is mostly polygenic. Neuropsychological and imaging studies indicate similar abnormalities in unaffected relatives of patients with GGE, supporting the concept that underlying alterations in bilateral frontothalamocortical networks are genetically determined. Contrary to popular belief, first-line anti-seizure medication often fails to provide seizure freedom in combination with good tolerability. Nevertheless, long-term follow-up studies have shown that with advancing age, many patients can discontinue their anti-seizure medication without seizure relapses. Several outcome predictors have been identified, but prognosis across the syndromes is more homogeneous than previously assumed. Overall, overlap in pathophysiology, seizure types, treatment responses and outcomes support the idea that GGEs are not separate nosological entities but represent a neurobiological continuum.
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Li T, Niu S, Qiu X, Zhai Z, Yang L, Chen L, Zhang XM. Altered Cerebral Blood Flow is Linked to Disease Duration in Patients with Generalized tonic‒clonic Seizures. Neuropsychiatr Dis Treat 2022; 18:2649-2659. [PMID: 36387946 PMCID: PMC9662018 DOI: 10.2147/ndt.s386509] [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: 08/17/2022] [Accepted: 10/29/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To investigate cerebral blood flow (CBF) characteristics in individuals with generalized tonic‒clonic seizures (GTCS) during the interictal phase using voxel-based analysis of 3D pseudocontinuous arterial spin labeling (PCASL). PATIENTS AND METHODS Patients with GTCS (GTCS group) (during the interictal period) and healthy volunteers (control group) underwent head MR imaging with a 3.0T MR scanner with a 3D PCASL sequence. CBF was compared between the two groups. Spearman correlations of CBF in regions of interest (ROIs) in GTCS patients with the duration of disease and age of onset were analyzed and corrected using the false discovery rate (FDR). RESULTS Twenty patients with GTCS (GTCS group) and twenty healthy volunteers (control group) were recruited for this study. On 3D PCASL, (1) GTCS patients had lower CBF in the brainstem, right cerebellum, right inferior temporal gyrus, parahippocampal gyrus, superior frontal gyrus, middle frontal gyrus, triangular part of inferior frontal gyrus, left temporal pole of superior temporal gyrus and thalamus and had higher CBF in the bilateral superior parietal gyri, precuneus, precentral gyri, postcentral gyri, and left dorsolateral superior frontal gyrus than controls. (2) The CBF of the right temporal pole of the middle temporal gyrus was negatively correlated with the duration of disease (PFDRcorrected<0.05), with a correlation coefficient r of -0.7333 and a PFDRcorrected value of 0.04. CONCLUSION Voxel-based analysis of 3D PCASL imaging can be used to sensitively detect brain perfusion differences in GTCS patients. The decrease in CBF in the right temporal pole of the middle temporal gyrus may be associated with disease onset. These findings may offer new perspectives on the pathogenesis of GTCS and the underlying pathophysiological changes associated with perfusion.
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Affiliation(s)
- Ting Li
- The First Affiliated Hospital, Jinan University, Guangzhou, People's Republic of China.,Medical Imaging Key Laboratory of Sichuan Province, and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, People's Republic of China
| | - Shaowei Niu
- Department of Infection, Affiliated Hospital of North Sichuan Medical College, Nanchong, People's Republic of China
| | - Xiang Qiu
- Department of Radiology, Integrated TCM & Western Medicine Hospital Affiliated to Chengdu University of TCM, Chengdu First People's Hospital, Chengdu, People's Republic of China
| | - Zhaohua Zhai
- Medical Imaging Key Laboratory of Sichuan Province, and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, People's Republic of China
| | - Lin Yang
- Medical Imaging Key Laboratory of Sichuan Province, and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, People's Republic of China
| | - Li Chen
- Medical Imaging Key Laboratory of Sichuan Province, and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, People's Republic of China
| | - Xiao Ming Zhang
- The First Affiliated Hospital, Jinan University, Guangzhou, People's Republic of China.,Medical Imaging Key Laboratory of Sichuan Province, and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, People's Republic of China
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Abstract
Impaired consciousness during seizures severely affects quality of life for people with
epilepsy but the mechanisms are just beginning to be understood. Consciousness is thought
to involve large-scale brain networks, so it is puzzling that focal seizures often impair
consciousness. Recent work investigating focal temporal lobe or limbic seizures in human
patients and experimental animal models suggests that impaired consciousness is caused by
active inhibition of subcortical arousal mechanisms. Focal limbic seizures exhibit
decreased neuronal firing in brainstem, basal forebrain, and thalamic arousal networks,
and cortical arousal can be restored when subcortical arousal circuits are stimulated
during seizures. These findings open the possibility of restoring arousal and
consciousness therapeutically during and following seizures by thalamic neurostimulation.
When seizures cannot be stopped by existing treatments, targeted subcortical stimulation
may improve arousal and consciousness, leading to improved safety and better psychosocial
function for people with epilepsy.
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Affiliation(s)
- Hal Blumenfeld
- Departments of Neurology, Neuroscience, Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
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Kumar A, Martin R, Chen W, Bauerschmidt A, Youngblood MW, Cunningham C, Si Y, Ezeani C, Kratochvil Z, Bronen J, Thomson J, Riordan K, Yoo JY, Shirka R, Manganas L, Krestel H, Hirsch LJ, Blumenfeld H. Simulated driving in the epilepsy monitoring unit: Effects of seizure type, consciousness, and motor impairment. Epilepsia 2021; 63:e30-e34. [PMID: 34816425 DOI: 10.1111/epi.17136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 11/29/2022]
Abstract
People with epilepsy face serious driving restrictions, determined using retrospective studies. To relate seizure characteristics to driving impairment, we aimed to study driving behavior during seizures with a simulator. Patients in the Yale New Haven Hospital undergoing video-electroencephalographic monitoring used a laptop-based driving simulator during ictal events. Driving function was evaluated by video review and analyzed in relation to seizure type, impairment of consciousness/responsiveness, or motor impairment during seizures. Fifty-one seizures in 30 patients were studied. In terms of seizure type, we found that focal to bilateral tonic-clonic or myoclonic seizures (5/5) and focal seizures with impaired consciousness/responsiveness (11/11) always led to driving impairment; focal seizures with spared consciousness/responsiveness (0/10) and generalized nonmotor (generalized spike-wave bursts; 1/19) usually did not lead to driving impairment. Regardless of seizure type, we found that seizures with impaired consciousness (15/15) or with motor involvement (13/13) always led to impaired driving, but those with spared consciousness (0/20) or spared motor function (5/38) usually did not. These results suggest that seizure types with impaired consciousness/responsiveness and abnormal motor function contribute to impaired driving. Expanding this work in a larger cohort could further determine how results with a driving simulator may translate into real world driving safety.
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Affiliation(s)
- Avisha Kumar
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Reese Martin
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - William Chen
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Andrew Bauerschmidt
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Mark W Youngblood
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Courtney Cunningham
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yang Si
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Cel Ezeani
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Zachary Kratochvil
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jared Bronen
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - James Thomson
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Katherine Riordan
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Ji Yeoun Yoo
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Romina Shirka
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Louis Manganas
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Heinz Krestel
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA.,Epilepsy Center of Frankfurt, Rhine-Main, Center for Personalized Translational Epilepsy Research, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Lawrence J Hirsch
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut, USA
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30
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Swinnen L, Chatzichristos C, Jansen K, Lagae L, Depondt C, Seynaeve L, Vancaester E, Van Dycke A, Macea J, Vandecasteele K, Broux V, De Vos M, Van Paesschen W. Accurate detection of typical absence seizures in adults and children using a two-channel electroencephalographic wearable behind the ears. Epilepsia 2021; 62:2741-2752. [PMID: 34490891 PMCID: PMC9292701 DOI: 10.1111/epi.17061] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/09/2021] [Accepted: 08/23/2021] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Patients with absence epilepsy sensitivity <10% of their absences. The clinical gold standard to assess absence epilepsy is a 24-h electroencephalographic (EEG) recording, which is expensive, obtrusive, and time-consuming to review. We aimed to (1) investigate the performance of an unobtrusive, two-channel behind-the-ear EEG-based wearable, the Sensor Dot (SD), to detect typical absences in adults and children; and (2) develop a sensitive patient-specific absence seizure detection algorithm to reduce the review time of the recordings. METHODS We recruited 12 patients (median age = 21 years, range = 8-50; seven female) who were admitted to the epilepsy monitoring units of University Hospitals Leuven for a 24-h 25-channel video-EEG recording to assess their refractory typical absences. Four additional behind-the-ear electrodes were attached for concomitant recording with the SD. Typical absences were defined as 3-Hz spike-and-wave discharges on EEG, lasting 3 s or longer. Seizures on SD were blindly annotated on the full recording and on the algorithm-labeled file and consequently compared to 25-channel EEG annotations. Patients or caregivers were asked to keep a seizure diary. Performance of the SD and seizure diary were measured using the F1 score. RESULTS We concomitantly recorded 284 absences on video-EEG and SD. Our absence detection algorithm had a sensitivity of .983 and false positives per hour rate of .9138. Blind reading of full SD data resulted in sensitivity of .81, precision of .89, and F1 score of .73, whereas review of the algorithm-labeled files resulted in scores of .83, .89, and .87, respectively. Patient self-reporting gave sensitivity of .08, precision of 1.00, and F1 score of .15. SIGNIFICANCE Using the wearable SD, epileptologists were able to reliably detect typical absence seizures. Our automated absence detection algorithm reduced the review time of a 24-h recording from 1-2 h to around 5-10 min.
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Affiliation(s)
- Lauren Swinnen
- Laboratory for Epilepsy Research, KU Leuven and Department of Neurology, University Hospitals, Leuven, Belgium
| | - Christos Chatzichristos
- Department of Electrical Engineering, STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Leuven, Belgium
| | - Katrien Jansen
- Department Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Lieven Lagae
- Department Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Chantal Depondt
- Department of Neurology, Hôpital Erasme, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Laura Seynaeve
- Department of Neurology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium.,Neuroprotection and Neuromodulation, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | | | | | - Jaiver Macea
- Laboratory for Epilepsy Research, KU Leuven and Department of Neurology, University Hospitals, Leuven, Belgium
| | - Kaat Vandecasteele
- Department of Electrical Engineering, STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Leuven, Belgium
| | - Victoria Broux
- Laboratory for Epilepsy Research, KU Leuven and Department of Neurology, University Hospitals, Leuven, Belgium
| | - Maarten De Vos
- Department of Electrical Engineering, STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Leuven, Belgium.,Department Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research, KU Leuven and Department of Neurology, University Hospitals, Leuven, Belgium
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31
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Sun Y, Li Y, Sun J, Zhang K, Tang L, Wu C, Gao Y, Liu H, Huang S, Hu Z, Xiang J, Wang X. Functional reorganization of brain regions into a network in childhood absence epilepsy: A magnetoencephalography study. Epilepsy Behav 2021; 122:108117. [PMID: 34246893 DOI: 10.1016/j.yebeh.2021.108117] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Epilepsy is considered as a network disorder. However, it is unknown how normal brain activity develops into the highly synchronized discharging activity seen in disordered networks. This study aimed to explore the epilepsy brain network and the significant re-combined brain areas in childhood absence epilepsy (CAE). METHODS Twenty-two children with CAE were recruited to study the neural source activity during ictal-onset and interictal periods at frequency bands of 1-30 Hz and 30-80 Hz with magnetoencephalography (MEG) scanning. Accumulated source imaging (ASI) was used to analyze the locations of neural source activity and peak source strength. RESULTS Most of the participants had more active source activity locations in the ictal-onset period rather than in the interictal period, both at 1-30 Hz and 30-80 Hz. The frontal lobe (FL), the temporo-parietal junction (T-P), and the parietal lobe (PL) became the main active areas of source activity during the ictal period, while the precuneus (PC), cuneus, and thalamus were relatively inactive. CONCLUSIONS Some brain areas become more excited and have increased source activity during seizures. These significant brain regions might be re-combined to form an epilepsy network that regulates the process of absence seizures. SIGNIFICANCE The study confirmed that important brain regions are reorganized in an epilepsy network, which provides a basis for exploring the network mechanism of CAE development. Imaging findings may provide a reference for clinical characteristics.
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Affiliation(s)
- Yulei Sun
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yihan Li
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jintao Sun
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Ke Zhang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Lu Tang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Caiyun Wu
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yuan Gao
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Hongxing Liu
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Shuyang Huang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Zheng Hu
- Department of Neurology, Nanjing Children's Hospital, Nanjing, Jiangsu 210029, China
| | - Jing Xiang
- Division of Neurology, MEG Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Xiaoshan Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
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Zheng Y, Xie Y, Qi M, Zhang L, Wang W, Zhang W, Sha L, Wu J, Li W, Wu T. Ginkgo Biloba Extract Is Comparable With Donepezil in Improving Functional Recovery in Alzheimer's Disease: Results From a Multilevel Characterized Study Based on Clinical Features and Resting-State Functional Magnetic Resonance Imaging. Front Pharmacol 2021; 12:721216. [PMID: 34413779 PMCID: PMC8369572 DOI: 10.3389/fphar.2021.721216] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/01/2021] [Indexed: 11/30/2022] Open
Abstract
Background: Ginkgo biloba extract (GBE) and donepezil have been reported to be effective in patients with Alzheimer's disease (AD). Nonetheless, how these drugs impact spontaneous brain activities and how they consequently improve functional recovery are currently unclear. Objectives: This study was to explore the efficacy of GBE vs. donepezil and their add-on efficacy on functional recovery and the adaption of spontaneous brain activities following pharmacologic treatment in patients with AD. Methods: Patients with AD were enrolled and assigned to the GBE group (n = 50), the donepezil group (n = 50), or the combined group (n = 50). Neuropsychological assessments, including minimum mental state examination (MMSE), Alzheimer's disease assessment scale-cognition (ADAS-Cog), instrumental activity of daily living (IADL), geriatric depression scale (GDS), neuropsychiatric inventory (NPI), and quality of life in Alzheimer's disease (QOL-AD), were conducted at baseline, 1 month, 3 months, and 6 months. Resting-state functional magnetic resonance imaging (rs-fMRI) was collected to compare the amplitude of low-frequency fluctuation (ALFF), percent amplitude of fluctuation (PerAF), regional homogeneity (ReHo), and degree centrality (DC) at baseline and 6 months. Results: No major significant differences were detected in all comparisons between groups across all follow-up time points. For intragroup comparison, MMSE and ADAS-Cog scores differed significantly across all follow-ups in three groups. The combined group showed significant improvement of GDS scores between baseline and 6 months (p = 0.007). The GBE group (p = 0.044) and donepezil group (p = 0.012) demonstrated significant improvement of NPI scores between baseline and 6 months. Significant correlations were observed between IADL and ALFF in the right gyrus rectus (p = 0.03) and in the left superior cerebellum gyrus (p = 0.01), between GDS and ALFF in the right middle temporal gyrus (p = 0.01), between NPI and PerAF in the left fusiform gyrus (p = 0.03), and between MMSE and ReHo in right superior frontal gyrus (p = 0.04). Conclusion: GBE was comparable with donepezil in the improvement of functional recovery in patients with AD while the combined application of GBE and donepezil seems unnecessary. GBE-mediated improvement of functional recovery was characterized by decreased ALFF values in the right gyrus rectus and decreased PerAF values in the left fusiform gyrus. These featured variations of imaging metrics in specific brain regions may serve as biomarkers in the monitoring of the therapeutic efficacy of GBE.
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Affiliation(s)
- Yu Zheng
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yi Xie
- Division of Brain Rehabilitation, Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ming Qi
- Departments of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ling Zhang
- Departments of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Wang
- Division of Brain Rehabilitation, Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wanrong Zhang
- Division of Brain Rehabilitation, Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Liju Sha
- Division of Brain Rehabilitation, Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jiawen Wu
- Division of Brain Rehabilitation, Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wanting Li
- Division of Brain Rehabilitation, Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ting Wu
- Division of Brain Rehabilitation, Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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Differentiating ictal/subclinical spikes and waves in childhood absence epilepsy by spectral and network analyses: A pilot study. Clin Neurophysiol 2021; 132:2222-2231. [PMID: 34311205 DOI: 10.1016/j.clinph.2021.06.011] [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: 12/22/2020] [Revised: 06/09/2021] [Accepted: 06/24/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Childhood absence epilepsy (CAE) is a disease with distinct seizure semiology and electroencephalographic (EEG) features. Differentiating ictal and subclinical generalized spikes and waves discharges (GSWDs) in the EEG is challenging, since they appear to be identical upon visual inspection. Here, spectral and functional connectivity (FC) analyses were applied to routine EEG data of CAE patients, to differentiate ictal and subclinical GSWDs. METHODS Twelve CAE patients with both ictal and subclinical GSWDs were retrospectively selected for this study. The selected EEG epochs were subjected to frequency analysis in the range of 1-30 Hz. Further, FC analysis based on the imaginary part of coherency was used to determine sensor level networks. RESULTS Delta, alpha and beta band frequencies during ictal GSWDs showed significantly higher power compared to subclinical GSWDs. FC showed significant network differences for all frequency bands, demonstrating weaker connectivity between channels during ictal GSWDs. CONCLUSION Using spectral and FC analyses significant differences between ictal and subclinical GSWDs in CAE patients were detected, suggesting that these features could be used for machine learning classification purposes to improve EEG monitoring. SIGNIFICANCE Identifying differences between ictal and subclinical GSWDs using routine EEG, may improve understanding of this syndrome and the management of patients with CAE.
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34
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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.
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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
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35
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Altered peri-seizure EEG microstate dynamics in patients with absence epilepsy. Seizure 2021; 88:15-21. [PMID: 33799135 DOI: 10.1016/j.seizure.2021.03.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 03/20/2021] [Accepted: 03/20/2021] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVE To investigate whether the parameters of EEG microstates changed before and after an absence seizure episode. METHODS AE patients with a current high frequency of seizures were included (n=21). Each included subject underwent a two-hour and 19-channel video EEG examination. Five epochs of 10-second EEG data in interictal, pre-seizure, and post-seizure states were collected from each AE patient. Five 10-second resting-state EEG epochs from sex- and age-matched HCs who reported no history of neurological or psychiatric disorders and visited the hospital for routine physical examinations were collected. Microstate analysis and source localization of microstates were performed using the LORETA KEY tool. RESULTS Compared with the resting-state EEGs of HCs, the interictal EEGs of AE patients showed a higher relative transition rate from microstates B to D (p<0.05). From interictal to pre-seizure EEG, the total time ratio of microstate C and the occurrence of microstate B decreased significantly, while the duration of microstate B increased significantly (p<0.05). Compared with pre-seizure EEGs, microstate C in post-seizure EEGs showed a significantly downregulated total time percentage and occurrence (p<0.05). The source localization of each microstate in each condition also varied and showed spatial recovery tends from pre- to post-seizure states. CONCLUSION Altered EEG microstate dynamics exist between inter-ictal EEGs of AE patients and resting-state EEGs of HCs and between pre- and post-seizure EEGs in AE patients. The EEG microstates of epileptic patients before and after absence seizures are characterized by a "slowdown" in transitions between microstates. Microstates might be used as an index to evaluate the temporal and spatial recovery process of absence seizures in AE.
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Frohlich J, Toker D, Monti MM. Consciousness among delta waves: a paradox? Brain 2021; 144:2257-2277. [PMID: 33693596 DOI: 10.1093/brain/awab095] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 02/12/2021] [Accepted: 02/25/2021] [Indexed: 01/29/2023] Open
Abstract
A common observation in EEG research is that consciousness vanishes with the appearance of delta (1 - 4 Hz) waves, particularly when those waves are high amplitude. High amplitude delta oscillations are very frequently observed in states of diminished consciousness, including slow wave sleep, anaesthesia, generalised epileptic seizures, and disorders of consciousness such as coma and vegetative state. This strong correlation between loss of consciousness and high amplitude delta oscillations is thought to stem from the widespread cortical deactivation that occurs during the "down states" or troughs of these slow oscillations. Recently, however, many studies have reported the presence of prominent delta activity during conscious states, which casts doubt on the hypothesis that high amplitude delta oscillations are an indicator of unconsciousness. These studies include work in Angelman syndrome, epilepsy, behavioural responsiveness during propofol anaesthesia, postoperative delirium, and states of dissociation from the environment such as dreaming and powerful psychedelic states. The foregoing studies complement an older, yet largely unacknowledged, body of literature that has documented awake, conscious patients with high amplitude delta oscillations in clinical reports from Rett syndrome, Lennox-Gastaut syndrome, schizophrenia, mitochondrial diseases, hepatic encephalopathy, and nonconvulsive status epilepticus. At the same time, a largely parallel body of recent work has reported convincing evidence that the complexity or entropy of EEG and magnetoencephalogram or MEG signals strongly relates to an individual's level of consciousness. Having reviewed this literature, we discuss plausible mechanisms that would resolve the seeming contradiction between high amplitude delta oscillations and consciousness. We also consider implications concerning theories of consciousness, such as integrated information theory and the entropic brain hypothesis. Finally, we conclude that false inferences of unconscious states can be best avoided by examining measures of electrophysiological complexity in addition to spectral power.
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Affiliation(s)
- Joel Frohlich
- Department of Psychology, University of California Los Angeles, 3423 Franz Hall, Los Angeles, California 90095, USA
| | - Daniel Toker
- Department of Psychology, University of California Los Angeles, 3423 Franz Hall, Los Angeles, California 90095, USA
| | - Martin M Monti
- Department of Psychology, University of California Los Angeles, 3423 Franz Hall, Los Angeles, California 90095, USA.,Department of Neurosurgery, UCLA Brain Injury Research Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
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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.
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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.
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Gruenbaum BF. Comparison of anaesthetic- and seizure-induced states of unconsciousness: a narrative review. Br J Anaesth 2021; 126:219-229. [PMID: 32951841 PMCID: PMC7844374 DOI: 10.1016/j.bja.2020.07.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/23/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022] Open
Abstract
In order to understand general anaesthesia and certain seizures, a fundamental understanding of the neurobiology of unconsciousness is needed. This review article explores similarities in neuronal and network changes during general anaesthesia and seizure-induced unconsciousness. Both seizures and anaesthetics cause disruption in similar anatomical structures that presumably lead to impaired consciousness. Despite differences in behaviour and mechanisms, both of these conditions are associated with disruption of the functionality of subcortical structures that mediate neuronal activity in the frontoparietal cortex. These areas are all likely to be involved in maintaining normal consciousness. An assessment of the similarities in the brain network disruptions with certain seizures and general anaesthesia might provide fresh insights into the mechanisms of the alterations of consciousness seen in these particular unconscious states, allowing for innovative therapies for seizures and the development of anaesthetic approaches targeting specific networks.
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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: 88] [Impact Index Per Article: 22.0] [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.
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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
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Sitnikova E, Smirnov K. Active avoidance learning in WAG/Rij rats with genetic predisposition to absence epilepsy. Brain Res Bull 2020; 165:198-208. [DOI: 10.1016/j.brainresbull.2020.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/23/2020] [Accepted: 10/05/2020] [Indexed: 11/29/2022]
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Gerster M, Berner R, Sawicki J, Zakharova A, Škoch A, Hlinka J, Lehnertz K, Schöll E. FitzHugh-Nagumo oscillators on complex networks mimic epileptic-seizure-related synchronization phenomena. CHAOS (WOODBURY, N.Y.) 2020; 30:123130. [PMID: 33380049 DOI: 10.1063/5.0021420] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
We study patterns of partial synchronization in a network of FitzHugh-Nagumo oscillators with empirical structural connectivity measured in human subjects. We report the spontaneous occurrence of synchronization phenomena that closely resemble the ones seen during epileptic seizures in humans. In order to obtain deeper insights into the interplay between dynamics and network topology, we perform long-term simulations of oscillatory dynamics on different paradigmatic network structures: random networks, regular nonlocally coupled ring networks, ring networks with fractal connectivities, and small-world networks with various rewiring probability. Among these networks, a small-world network with intermediate rewiring probability best mimics the findings achieved with the simulations using the empirical structural connectivity. For the other network topologies, either no spontaneously occurring epileptic-seizure-related synchronization phenomena can be observed in the simulated dynamics, or the overall degree of synchronization remains high throughout the simulation. This indicates that a topology with some balance between regularity and randomness favors the self-initiation and self-termination of episodes of seizure-like strong synchronization.
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Affiliation(s)
- Moritz Gerster
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Rico Berner
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Jakub Sawicki
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Anna Zakharova
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Antonín Škoch
- National Institute of Mental Health, Topolová 748, 250 67 Klecany, Czech Republic
| | - Jaroslav Hlinka
- National Institute of Mental Health, Topolová 748, 250 67 Klecany, Czech Republic
| | - Klaus Lehnertz
- Department of Epileptology, University of Bonn Medical Centre, Venusberg Campus 1, 53127 Bonn, Germany
| | - Eckehard Schöll
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
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Liu W, Yue Q, Wu X, Gong Q, Zhou D. Abnormal blood oxygen level-dependent fluctuations and remote connectivity in sleep-related hypermotor epilepsy. Acta Neurol Scand 2020; 143:514-520. [PMID: 33210736 DOI: 10.1111/ane.13379] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 11/16/2020] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Sleep-related hypermotor epilepsy (SHE) is a form of the epileptic syndrome that involves stereotyped hypermotor seizures and presents as asymmetric tonic or dystonic posturing events. We aimed to investigate the brain activities of SHE patients using structural and functional magnetic resonance imaging (fMRI). METHODS A total of 41 patients with SHE and 41 age- and sex-matched healthy controls (HCs) were prospectively enrolled and assessed using fMRI. The two groups were compared in amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo), and potential correlations between these measures and clinical features were also examined. The involvement of functional network integration was explored by analyzing seed-based functional connectivity. RESULTS In SHE patients, ALFF in the right precentral gyrus was significantly higher than in HCs, and ReHo in the left postcentral and right precentral gyrus was higher. None of the brain regions had lower ALFF or ReHo compared to HCs. ReHo in the left postcentral gyrus and ALFF in the right precentral gyrus were both negatively correlated with epilepsy duration. Patients with SHE had higher functional connectivity mainly in the precuneus, postcentral gyrus, and supplementary motor area. However, none of the brain regions in SHE group presented lower functional connectivity than in HCs. SHE is associated with disrupted regional and interregional functional activities. CONCLUSIONS The patients showed abnormalities within the sensorimotor gyrus and supplementary motor area, suggesting spontaneous fluctuations correlated with remote functional brain network. These results at the whole-brain level argue for further investigation into connectivity disturbance in SHE.
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Affiliation(s)
- Wenyu Liu
- Department of Neurology West China Hospital Sichuan University Chengdu China
| | - Qiang Yue
- Department of Radiology Huaxi MR Research Center (HMRRC) West China Hospital Sichuan University Chengdu China
| | - Xintong Wu
- Department of Neurology West China Hospital Sichuan University Chengdu China
| | - Qiyong Gong
- Department of Radiology Huaxi MR Research Center (HMRRC) West China Hospital Sichuan University Chengdu China
| | - Dong Zhou
- Department of Neurology West China Hospital Sichuan University Chengdu China
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Qin Y, Zhang N, Chen Y, Tan Y, Dong L, Xu P, Guo D, Zhang T, Yao D, Luo C. How Alpha Rhythm Spatiotemporally Acts Upon the Thalamus-Default Mode Circuit in Idiopathic Generalized Epilepsy. IEEE Trans Biomed Eng 2020; 68:1282-1292. [PMID: 32976091 DOI: 10.1109/tbme.2020.3026055] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
GOAL Idiopathic generalized epilepsy (IGE) represents generalized spike-wave discharges (GSWD) and distributed changes in thalamocortical circuit. The purpose of this study is to investigate how the ongoing alpha oscillation acts upon the local temporal dynamics and spatial hyperconnectivity in epilepsy. METHODS We evaluated the spatiotemporal regulation of alpha oscillations in epileptic state based on simultaneous EEG-fMRI recordings in 45 IGE patients. The alpha-BOLD temporal consistency, as well as the effect of alpha power windows on dynamic functional connectivity strength (dFCS) was analyzed. Then, stable synchronization networks during GSWD were constructed, and the spatial covariation with alpha-based network integration was investigated. RESULTS Increased temporal covariation was demonstrated between alpha power and BOLD fluctuations in thalamus and distributed cortical regions in IGE. High alpha power had inhibition effect on dFCS in healthy controls, while in epilepsy, high alpha windows arose along with the enhancement of dFCS in thalamus, caudate and some default mode network (DMN) regions. Moreover, synchronization networks in GSWD-before, GSWD-onset and GSWD-after stages were constructed, and the connectivity strength in prominent hub nodes (precuneus, thalamus) was associated with the spatially disturbed alpha-based network integration. CONCLUSION The results indicated spatiotemporal regulation of alpha in epilepsy by means of the increased power and decreased coherence communication. It provided links between alpha rhythm and the altered temporal dynamics, as well as the hyperconnectivity in thalamus-default mode circuit. SIGNIFICANCE The combination between neural oscillations and epileptic representations may be of clinical importance in terms of seizure prediction and non-invasive interventions.
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Ikemoto S, Hamano SI, Yokota S, Koichihara R, Hirata Y, Matsuura R. High-power, frontal-dominant ripples in absence status epilepticus during childhood. Clin Neurophysiol 2020; 131:1204-1209. [DOI: 10.1016/j.clinph.2020.02.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/28/2020] [Accepted: 02/12/2020] [Indexed: 11/25/2022]
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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]
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Ratcliffe C, Wandschneider B, Baxendale S, Thompson P, Koepp MJ, Caciagli L. Cognitive Function in Genetic Generalized Epilepsies: Insights From Neuropsychology and Neuroimaging. Front Neurol 2020; 11:144. [PMID: 32210904 PMCID: PMC7076110 DOI: 10.3389/fneur.2020.00144] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 02/10/2020] [Indexed: 12/17/2022] Open
Abstract
Genetic generalized epilepsies (GGE), previously called idiopathic generalized epilepsies, constitute about 20% of all epilepsies, and include childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone (CAE, JAE, JME, and GGE-GTCS, respectively). GGE are characterized by high heritability, likely underlain by polygenetic mechanisms, which may relate to atypical neurodevelopmental trajectories. Age of onset ranges from pre-school years, for CAE, to early adulthood for GGE-GTCS. Traditionally, GGE have been considered benign, a belief contrary to evidence from neuropsychology studies conducted over the last two decades. In JME, deficits in executive and social functioning are common findings and relate to impaired frontal lobe function. Studies using neuropsychological measures and cognitive imaging paradigms provide evidence for hyperconnectivity between prefrontal and motor cortices, aberrant fronto-thalamo-cortical connectivity, and reduced fronto-cortical and subcortical gray matter volumes, which are associated with altered cognitive performance. Recent research has also identified associations between abnormal hippocampal morphometry and fronto-temporal activation during episodic memory. Longitudinal studies on individuals with newly diagnosed JME have observed cortical dysmaturation, which is paralleled by delayed cognitive development compared to the patients' peers. Comorbidities and cognitive deficits observed in other GGE subtypes, such as visuo-spatial and language deficits in both CAE and JAE, have also been correlated with atypical neurodevelopment. Although it remains unclear whether cognitive impairment profiles differ amongst GGE subtypes, effects may become more pronounced with disease duration, particularly in absence epilepsies. Finally, there is substantial evidence that patients with JME and their unaffected siblings share patterns of cognitive deficits, which is indicative of an underlying genetic etiology (endophenotype), independent of seizures and anti-epileptic medication.
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Affiliation(s)
- Corey Ratcliffe
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom
| | - Britta Wandschneider
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom
| | - Sallie Baxendale
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom
| | - Pamela Thompson
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom
| | - Matthias J. Koepp
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom
| | - Lorenzo Caciagli
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
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Shi Q, Zhang T, Miao A, Sun J, Sun Y, Chen Q, Hu Z, Xiang J, Wang X. Differences Between Interictal and Ictal Generalized Spike-Wave Discharges in Childhood Absence Epilepsy: A MEG Study. Front Neurol 2020; 10:1359. [PMID: 32038453 PMCID: PMC6992575 DOI: 10.3389/fneur.2019.01359] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 12/09/2019] [Indexed: 12/05/2022] Open
Abstract
Purpose: To investigate the differences between interictal and ictal generalized spike-wave discharges (GSWDs) for insights on how epileptic activity propagates and the physiopathological mechanisms underlying childhood absence epilepsy (CAE). Methods: Twenty-five patients with CAE were studied using magnetoencephalography (MEG). MEG data were digitized at 6,000 Hz during the interictal and ictal GSWDs. GSWDs were analyzed at both neural magnetic source levels and functional connectivity (FC) in multifrequency bands: delta (1–4 Hz), theta (4–8 Hz), alpha (8–12 Hz), beta (12–30 Hz), gamma (30–80 Hz), ripple (80–250 Hz), and fast ripple (250–500 Hz). Brain FC was studied with the posterior cingulate cortex/precuneus (PCC/pC) as the seed region. Results: The magnetic source of interictal GSWDs mainly locates in the PCC/pC region at 4–8 and 8–12 Hz, while that of ictal GSWDs mainly locates in the medial frontal cortex (MFC) at 80–250 Hz. There were statistically significant differences between interictal and ictal GSWDs (p < 0.05). The FC network involving the PCC/pC showed strong connections in the anterior-posterior pathways (mainly with the frontal cortex) at 80–250 Hz during ictal GSWDs, while the interictal GSWDs FC were mostly limited to the posterior cortex region. There was no significant difference in the magnetic source strength among interictal and ictal GSWDs at all bandwidths. Conclusions: There are significant disparities in the source localization and FC between interictal and ictal GSWDs. Low-frequency activation in the PCC/pC during inhibition of seizures possibly relates to the maintenance of consciousness during interictal GSWDs. High-frequency oscillations (HFOs) of the MFC during CAE may associate with the inducing or occurrence of GSWDs. Weakened network connections may be in favor of preventing overexcitability and relates to the termination of GSWDs.
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Affiliation(s)
- Qi Shi
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Tingting Zhang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Ailiang Miao
- 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
| | - Qiqi Chen
- MEG Center, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Zheng Hu
- Department of Neurology, Nanjing Children's Hospital, Nanjing, China
| | - Jing Xiang
- Division of Neurology, MEG Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Xiaoshan Wang
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
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Williams MS, Lecas S, Charpier S, Mahon S. Phase-dependent modulation of cortical and thalamic sensory responses during spike-and-wave discharges. Epilepsia 2020; 61:330-341. [PMID: 31912497 DOI: 10.1111/epi.16422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/14/2019] [Accepted: 12/16/2019] [Indexed: 12/29/2022]
Abstract
OBJECTIVE The neuronal underpinnings of impaired consciousness during absence seizures remain largely unknown. Spike-and-wave (SW) activity associated with absences imposes two extremely different states in cortical neurons, which transition from suprathreshold synaptic depolarizations during spike phases to membrane hyperpolarization and electrical silence during wave phases. To investigate whether this rhythmic alternation of neuronal states affects the processing of sensory information during seizures, we examined cortical and thalamic responsiveness to brief sensory stimuli in the different phases of the epileptic cycle. METHODS Electrocorticographic (ECoG) monitoring from the primary somatosensory cortex combined with intracellular recordings of subjacent pyramidal neurons, or extracellular recordings of somatosensory thalamic neurons, were performed in the Genetic Absence Epilepsy Rat From Strasbourg. Sensory stimuli consisted of pulses of compressed air applied to the contralateral whiskers. RESULTS Whisker stimuli delivered during spike phases evoked smaller depolarizing synaptic potentials and fewer action potentials in cortical neurons compared to stimuli occurring during wave phases. This spike-related attenuation of cortical responsiveness was accompanied by a reduced neuronal membrane resistance, likely due to the large increase in synaptic conductance. Sensory-evoked firing in thalamocortical neurons was also decreased during ECoG spikes as compared to wave phases, indicating that time-to-time changes in the thalamocortical volley may also contribute to the variability of cortical responses during seizures. SIGNIFICANCE These findings demonstrate that thalamocortical sensory processing during absence seizures is nonstationary and strongly suggest that the cortical impact of a given environmental stimulus is conditioned by its exact timing relative to the SW cycle. The lack of stability of thalamic and cortical responses along seizures may contribute to impaired conscious sensory perception during absences.
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Affiliation(s)
- Mark S Williams
- Brain and Spine Institute, National Institute of Health and Medical Research Mixed Unit of Research 1127, National Center for Scientific Research Mixed Unit of Research 7225, Pitié-Salpêtrière Hospital, Paris, France
| | - Sarah Lecas
- Brain and Spine Institute, National Institute of Health and Medical Research Mixed Unit of Research 1127, National Center for Scientific Research Mixed Unit of Research 7225, Pitié-Salpêtrière Hospital, Paris, France.,Sorbonne University, Pierre and Marie Curie University, Paris, France
| | - Stéphane Charpier
- Brain and Spine Institute, National Institute of Health and Medical Research Mixed Unit of Research 1127, National Center for Scientific Research Mixed Unit of Research 7225, Pitié-Salpêtrière Hospital, Paris, France.,Sorbonne University, Pierre and Marie Curie University, Paris, France
| | - Séverine Mahon
- Brain and Spine Institute, National Institute of Health and Medical Research Mixed Unit of Research 1127, National Center for Scientific Research Mixed Unit of Research 7225, Pitié-Salpêtrière Hospital, Paris, France
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Spike-and-Wave Discharges Are Not Pathological Sleep Spindles, Network-Level Aspects of Age-Dependent Absence Seizure Development in Rats. eNeuro 2020; 7:ENEURO.0253-19.2019. [PMID: 31862790 PMCID: PMC6944477 DOI: 10.1523/eneuro.0253-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 11/04/2019] [Accepted: 12/11/2019] [Indexed: 12/28/2022] Open
Abstract
Spike-and-wave discharges (SWDs) of absence epilepsy are considered as pathologic alterations of sleep spindles; however, their network-level relationship has never been convincingly revealed. In order to observe the development and generalization of the thalamocortical SWDs and the concomitant alterations of sleep related oscillations, we performed local field potential (LFP) and single unit recordings in rats for three months during their maturation. We found that while SWDs and spindles look similar in young, they become different with maturation and shift to appear in different brain states. Thus, despite being generated by the same network, they are likely two distinct manifestations of the thalamocortical activity. We show that while spindles are already mainly global oscillations, SWDs appear mainly only focally in young. They become capable to generalize later with maturation, when the out-of-focus brain regions develop a decreased inhibitory/excitatory balance. These results suggest that a hyperexcitable focus is not sufficient alone to drive generalized absence seizures. Importantly, we also found the gradual age dependent disappearance of sleep spindles coinciding with the simultaneous gradual emergence of spike and waves, which both could be reversed by the proper dosing of ethosuximide (ETX). Based on these observations we conclude that the absence seizure development might be a multi-step process, which might involve the functional impairment of cortical interneurons and network-level changes that negatively affect sleep quality.
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