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Pigorini A, Avanzini P, Barborica A, Bénar CG, David O, Farisco M, Keller CJ, Manfridi A, Mikulan E, Paulk AC, Roehri N, Subramanian A, Vulliémoz S, Zelmann R. Simultaneous invasive and non-invasive recordings in humans: A novel Rosetta stone for deciphering brain activity. J Neurosci Methods 2024; 408:110160. [PMID: 38734149 DOI: 10.1016/j.jneumeth.2024.110160] [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: 12/18/2023] [Revised: 04/10/2024] [Accepted: 05/01/2024] [Indexed: 05/13/2024]
Abstract
Simultaneous noninvasive and invasive electrophysiological recordings provide a unique opportunity to achieve a comprehensive understanding of human brain activity, much like a Rosetta stone for human neuroscience. In this review we focus on the increasingly-used powerful combination of intracranial electroencephalography (iEEG) with scalp electroencephalography (EEG) or magnetoencephalography (MEG). We first provide practical insight on how to achieve these technically challenging recordings. We then provide examples from clinical research on how simultaneous recordings are advancing our understanding of epilepsy. This is followed by the illustration of how human neuroscience and methodological advances could benefit from these simultaneous recordings. We conclude with a call for open data sharing and collaboration, while ensuring neuroethical approaches and argue that only with a true collaborative approach the promises of simultaneous recordings will be fulfilled.
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Affiliation(s)
- Andrea Pigorini
- Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy; UOC Maxillo-facial Surgery and dentistry, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy.
| | - Pietro Avanzini
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Parma, Italy
| | | | - Christian-G Bénar
- Aix Marseille Univ, Inserm, U1106, INS, Institut de Neurosciences des Systèmes, Marseille, France
| | - Olivier David
- Aix Marseille Univ, Inserm, U1106, INS, Institut de Neurosciences des Systèmes, Marseille, France
| | - Michele Farisco
- Centre for Research Ethics and Bioethics, Department of Public Health and Caring Sciences, Uppsala University, P.O. Box 256, Uppsala, SE 751 05, Sweden; Science and Society Unit Biogem, Biology and Molecular Genetics Institute, Via Camporeale snc, Ariano Irpino, AV 83031, Italy
| | - Corey J Keller
- Department of Psychiatry & Behavioral Sciences, Stanford University Medical Center, Stanford, CA 94305, USA; Wu Tsai Neurosciences Institute, Stanford University Medical Center, Stanford, CA 94305, USA; Veterans Affairs Palo Alto Healthcare System, and the Sierra Pacific Mental Illness, Research, Education, and Clinical Center (MIRECC), Palo Alto, CA 94394, USA
| | - Alfredo Manfridi
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - Ezequiel Mikulan
- Department of Health Sciences, Università degli Studi di Milano, Milan, Italy
| | - Angelique C Paulk
- Department of Neurology and Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Nicolas Roehri
- EEG and Epilepsy Unit, Dpt of Clinical Neurosciences, Geneva University Hospitals and University of Geneva, Switzerland
| | - Ajay Subramanian
- Department of Psychiatry & Behavioral Sciences, Stanford University Medical Center, Stanford, CA 94305, USA; Wu Tsai Neurosciences Institute, Stanford University Medical Center, Stanford, CA 94305, USA; Veterans Affairs Palo Alto Healthcare System, and the Sierra Pacific Mental Illness, Research, Education, and Clinical Center (MIRECC), Palo Alto, CA 94394, USA
| | - Serge Vulliémoz
- EEG and Epilepsy Unit, Dpt of Clinical Neurosciences, Geneva University Hospitals and University of Geneva, Switzerland
| | - Rina Zelmann
- Department of Neurology and Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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Fernández-Torre JL, Hernández-Hernández MA, Cherchi MS, Mato-Mañas D, de Lucas EM, Gómez-Ruiz E, Vázquez-Higuera JL, Fanjul-Vélez F, Arce-Diego JL, Martín-Láez R. Comparison of Continuous Intracortical and Scalp Electroencephalography in Comatose Patients with Acute Brain Injury. Neurocrit Care 2024:10.1007/s12028-024-02016-z. [PMID: 38918336 DOI: 10.1007/s12028-024-02016-z] [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: 11/29/2023] [Accepted: 05/16/2024] [Indexed: 06/27/2024]
Abstract
BACKGROUND Depth electroencephalography (dEEG) is a recent invasive monitoring technique used in patients with acute brain injury. This study aimed to describe in detail the clinical manifestations of nonconvulsive seizures (NCSzs) with and without a surface EEG correlate, analyze their long-standing effects, and provide data that contribute to understanding the significance of certain scalp EEG patterns observed in critically ill patients. METHODS We prospectively enrolled a cohort of 33 adults with severe acute brain injury admitted to the neurological intensive care unit. All of them underwent multimodal invasive monitoring, including dEEG. All patients were scanned on a 3T magnetic resonance imaging scanner at 6 months after hospital discharge, and mesial temporal atrophy (MTA) was calculated using a visual scale. RESULTS In 21 (65.6%) of 32 study participants, highly epileptiform intracortical patterns were observed. A total of 11 (34.3%) patients had electrographic or electroclinical seizures in the dEEG, of whom 8 had both spontaneous and stimulus-induced (SI) seizures, and 3 patients had only spontaneous intracortical seizures. An unequivocal ictal scalp correlate was observed in only 3 (27.2%) of the 11 study participants. SI-NCSzs occurred during nursing care, medical procedures, and family visits. Subtle clinical manifestations, such as restlessness, purposeless stereotyped movements of the upper limbs, ventilation disturbances, jerks, head movements, hyperextension posturing, chewing, and oroalimentary automatisms, occurred during intracortical electroclinical seizures. MTA was detected in 18 (81.8%) of the 22 patients. There were no statistically significant differences between patients with MTA with and without seizures or status epilepticus. CONCLUSIONS Most NCSzs in critically ill comatose patients remain undetectable on scalp EEG. SI-NCSzs frequently occur during nursing care, medical procedures, and family visits. Semiology of NCSzs included ictal minor signs and subtle symptoms, such as breathing pattern changes manifested as patient-ventilator dyssynchrony.
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Affiliation(s)
- José L Fernández-Torre
- Department of Clinical Neurophysiology, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain.
- Department of Physiology and Pharmacology, School of Medicine, University of Cantabria, 39008, Santander, Cantabria, Spain.
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain.
| | - Miguel A Hernández-Hernández
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Intensive Medicine, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - Marina S Cherchi
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Intensive Medicine, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - David Mato-Mañas
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Neurosurgery, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - Enrique Marco de Lucas
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Radiology, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
- Department of Medical-Surgical Sciences, School of Medicine, University of Cantabria, 39008, Santander, Cantabria, Spain
| | - Elsa Gómez-Ruiz
- Department of Psychiatry, Marqués de Valdecilla University Hospital Santander, 39008, Cantabria, Spain
| | - José L Vázquez-Higuera
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Neurology, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - Félix Fanjul-Vélez
- Biomedical Engineering Group, Tecnología Electrónica, Ingeniería de Sistemas y Automática (TEISA) Department, University of Cantabria, 39005, Santander, Cantabria, Spain
| | - José L Arce-Diego
- Biomedical Engineering Group, Tecnología Electrónica, Ingeniería de Sistemas y Automática (TEISA) Department, University of Cantabria, 39005, Santander, Cantabria, Spain
| | - Rubén Martín-Láez
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Neurosurgery, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
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Bolzan A, Benoit J, Pizzo F, Makhalova J, Villeneuve N, Carron R, Scavarda D, Bartolomei F, Lagarde S. Correspondence between scalp-EEG and stereoelectroencephalography seizure-onset patterns in patients with MRI-negative drug-resistant focal epilepsy. Epilepsia Open 2024; 9:568-581. [PMID: 38148028 PMCID: PMC10984298 DOI: 10.1002/epi4.12886] [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: 09/11/2023] [Revised: 11/28/2023] [Accepted: 12/14/2023] [Indexed: 12/28/2023] Open
Abstract
OBJECTIVE Our objective was to evaluate the relationship between scalp-EEG and stereoelectroencephalography (SEEG) seizure-onset patterns (SOP) in patients with MRI-negative drug-resistant focal epilepsy. METHODS We analyzed retrospectively 41 patients without visible lesion on brain MRI who underwent video-EEG followed by SEEG. We defined five types of SOPs on scalp-EEG and eight types on SEEG. We examined how various clinical variables affected scalp-EEG SOPs. RESULTS The most prevalent scalp SOPs were rhythmic sinusoidal activity (56.8%), repetitive epileptiform discharges (22.7%), and paroxysmal fast activity (15.9%). The presence of paroxysmal fast activity on scalp-EEG was always seen without delay from clinical onset and correlated with the presence of low-voltage fast activity in SEEG (sensitivity = 22.6%, specificity = 100%). The main factor explaining the discrepancy between the scalp and SEEG SOPs was the delay between clinical and scalp-EEG onset. There was a correlation between the scalp and SEEG SOPs when the scalp onset was simultaneous with the clinical onset (p = 0.026). A significant delay between clinical and scalp discharge onset was observed in 25% of patients and featured always with a rhythmic sinusoidal activity on scalp, corresponding to similar morphology of the discharge on SEEG. The presence of repetitive epileptiform discharges on scalp was associated with an underlying focal cortical dysplasia (sensitivity = 30%, specificity = 90%). There was no significant association between the scalp SOP and the epileptogenic zone location (deep or superficial), or surgical outcome. SIGNIFICANCE In patients with MRI-negative focal epilepsy, scalp SOP could suggest the SEEG SOP and some etiology (focal cortical dysplasia) but has no correlation with surgical prognosis. Scalp SOP correlates with the SEEG SOP in cases of simultaneous EEG and clinical onset; otherwise, scalp SOP reflects the propagation of the SEEG discharge. PLAIN LANGUAGE SUMMARY We looked at the correspondence between the electrical activity recorded during the start of focal seizure using scalp and intracerebral electrodes in patients with no visible lesion on MRI. If there is a fast activity on scalp, it reflects similar activity inside the brain. We found a good correspondence between scalp and intracerebral electrical activity for cases without significant delay between clinical and scalp electrical onset (seen in 75% of the cases we studied). Visualizing repetitive epileptic activity on scalp could suggest a particular cause of the epilepsy: a subtype of brain malformation called focal cortical dysplasia.
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Affiliation(s)
- Anna Bolzan
- APHM, Timone Hospital, Epileptology and Cerebral RhythmologyMarseilleFrance
| | - Jeanne Benoit
- CHU de Nice, Epileptology DepartmentUniversité Côte d'Azur, UMR2CA (URRIS)NiceFrance
| | - Francesca Pizzo
- APHM, Timone Hospital, Epileptology and Cerebral RhythmologyMarseilleFrance
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseilleFrance
| | - Julia Makhalova
- APHM, Timone Hospital, Epileptology and Cerebral RhythmologyMarseilleFrance
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseilleFrance
- APHM, Timone Hospital, CEMEREMMarseilleFrance
| | | | - Romain Carron
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseilleFrance
- APHM, Timone Hospital, Stereotactic and Functional Neurosurgery, Gamma UnitMarseilleFrance
| | - Didier Scavarda
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseilleFrance
- APHM, Timone Hospital, Paediatric NeurosurgeryMarseilleFrance
| | - Fabrice Bartolomei
- APHM, Timone Hospital, Epileptology and Cerebral RhythmologyMarseilleFrance
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseilleFrance
| | - Stanislas Lagarde
- APHM, Timone Hospital, Epileptology and Cerebral RhythmologyMarseilleFrance
- Aix Marseille Univ, INSERM, INS, Inst Neurosci SystMarseilleFrance
- University Hospitals of Geneva (HUG), University of Geneva (UNIGE)GenevaSwitzerland
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Ghulaxe Y, Joshi A, Chavada J, Huse S, Kalbande B, Sarda PP. Understanding Focal Seizures in Adults: A Comprehensive Review. Cureus 2023; 15:e48173. [PMID: 38046728 PMCID: PMC10693312 DOI: 10.7759/cureus.48173] [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: 08/28/2023] [Accepted: 11/02/2023] [Indexed: 12/05/2023] Open
Abstract
Focal or partial seizures are a common neurological disorder affecting adults. This review aims to provide an in-depth understanding of focal seizures in adults, including their classification, clinical presentation, etiology, diagnosis, and management. This article seeks to enhance awareness and knowledge among medical professionals and the general public by exploring the latest research and clinical insights. Standard electroencephalography (EEG) and recordings in presurgical electrode depth in humans provide a clear definition of patterns similar to focal seizures. Models of animals with partial seizures and epilepsy mimic seizure patterns with comparable characteristics. However, the network factors supporting interictal spikes, as well as the start, development, and end of seizures remain obscure. According to recent research, inhibitory networks are heavily implicated at the beginning of seizures, and extracellular potassium alterations help start and maintain seizure continuation. An increase in network synchronization, which may be caused by both excitatory and inhibitory pathways, is correlated with the cessation of a partial seizure. Recent research on temporal lobe focal seizures in human and animal models leads to the hypothesis that the active blocking of subcortical arousal processes brings on unconsciousness. Brainstem, basal forebrain, and thalamic arousal networks' neuronal firing is diminished during focal limbic seizures, and cortical arousal can be recovered when subcortical arousal circuits are engaged. These results suggest that thalamic neurostimulation may be therapeutic to restore arousal and consciousness during and after seizures. Targeted subcortical stimulation may increase arousal and consciousness when current treatments cannot halt seizures, enhancing safety and psychosocial function for epileptic patients. We embark on an investigation into adult focal seizures in this thorough review that goes beyond a cursory knowledge of their clinical symptoms.
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Affiliation(s)
- Yash Ghulaxe
- Department of Community Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Abhishek Joshi
- Department of Community Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Jay Chavada
- Department of Community Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Shreyash Huse
- Department of Community Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Bhakti Kalbande
- Department of Dentistry, Sharad Pawar Dental College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Prayas P Sarda
- Department of Community Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
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Carlson CA. Psychogenic Nonepileptic Seizures-High Mortality Rate Is a 'Wake-Up Call'. J Pers Med 2023; 13:892. [PMID: 37373881 DOI: 10.3390/jpm13060892] [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: 04/25/2023] [Revised: 05/18/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023] Open
Abstract
Patients with epilepsy have an elevated mortality rate compared to the general population and now studies are showing a comparable death ratio in patients diagnosed with psychogenic nonepileptic seizures. The latter is a top differential diagnosis for epilepsy and the unexpected mortality rate in these patients underscores the importance of an accurate diagnosis. Experts have called for more studies to elucidate this finding but the explanation is already available, embedded in the existing data. To illustrate, a review of the diagnostic practice in epilepsy monitoring units, of the studies examining mortality in PNES and epilepsy patients, and of the general clinical literature on the two populations was conducted. The analysis reveals that the scalp EEG test result, which distinguishes a psychogenic from an epileptic seizure, is highly fallible; that the clinical profiles of the PNES and epilepsy patient populations are virtually identical; and that both are dying of natural and non-natural causes including sudden unexpected death associated with confirmed or suspected seizure activity. The recent data showing a similar mortality rate simply constitutes more confirmatory evidence that the PNES population consists largely of patients with drug-resistant scalp EEG-negative epileptic seizures. To reduce the morbidity and mortality in these patients, they must be given access to treatments for epilepsy.
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Affiliation(s)
- Catherine A Carlson
- Minnesota Judicial Branch Psychological Services Division, Minneapolis, MN 55487, USA
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Ferrand M, Baumann C, Aron O, Vignal JP, Jonas J, Tyvaert L, Colnat-Coulbois S, Koessler L, Maillard L. Intracerebral Correlates of Scalp EEG Ictal Discharges Based on Simultaneous Stereo-EEG Recordings. Neurology 2023; 100:e2045-e2059. [PMID: 36963841 PMCID: PMC10186237 DOI: 10.1212/wnl.0000000000207135] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/18/2023] [Indexed: 03/26/2023] Open
Abstract
BACKGROUND AND OBJECTIVES It remains unknown to what extent ictal scalp EEG can accurately predict the localization of the intracerebral seizure onset in presurgical evaluation of drug-resistant epilepsies. In this study, we aimed to define homogeneous ictal scalp EEG profiles (based on their first ictal abnormality) and assess their localizing value using simultaneously recorded scalp EEG and stereo-EEG. METHODS We retrospectively included consecutive patients with drug-resistant focal epilepsy who had simultaneous stereo-EEG and scalp EEG recordings of at least 1 seizure in the epileptology unit in Nancy, France. We analyzed 1 seizure per patient and used hierarchical cluster analysis to group similar seizure profiles on scalp EEG and then performed a descriptive analysis of their intracerebral correlates. RESULTS We enrolled 129 patients in this study. The hierarchical cluster analysis showed 6 profiles on scalp EEG first modification. None were specific to a single intracerebral localization. The "normal EEG" and "blurred EEG" clusters (early muscle artifacts) comprised only 5 patients each and corresponded to no preferential intracerebral localization. The "temporal discharge" cluster (n = 46) was characterized by theta or delta discharges on ipsilateral anterior temporal scalp electrodes and corresponded to a preferential mesial temporal intracerebral localization. The "posterior discharge" cluster (n = 42) was characterized by posterior ipsilateral or contralateral rhythmic alpha discharges or slow waves on scalp and corresponded to a preferential temporal localization. However, this profile was the statistically most frequent scalp EEG correlate of occipital and parietal seizures. The "diffuse suppression" cluster (n = 9) was characterized by a bilateral and diffuse background activity suppression on scalp and corresponded to mesial, and particularly insulo-opercular, localization. Finally, the "frontal discharge" cluster (n = 22) was characterized by bilateral frontal rhythmic fast activity or preictal spike on scalp and corresponded to preferential ventrodorsal frontal intracerebral localizations. DISCUSSION The hierarchical cluster analysis identified 6 seizure profiles regarding the first abnormality on scalp EEG. None of them were specific of a single intracerebral localization. Nevertheless, the strong relationships between the "temporal," "frontal," "diffuse suppression," and "posterior" profiles and intracerebral discharge localizations may contribute to hierarchize hypotheses derived from ictal scalp EEG analysis regarding intracerebral seizure onset.
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Affiliation(s)
- Mickaël Ferrand
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Cédric Baumann
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Olivier Aron
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Jean-Pierre Vignal
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Jacques Jonas
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Louise Tyvaert
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Sophie Colnat-Coulbois
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Laurent Koessler
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France
| | - Louis Maillard
- From the Department of Neurology (M.F., O.A., J.-P.V., J.J., L.T., L.M.), and University Hospital of Nancy, Lorraine University; Department of Epidemiology and Clinical Evaluation (C.B.), INSERM CIC-EC CIE6, Lorraine University, Vandoeuvre; Neurosciences of Systems and Cognition Project (O.A., J.J., L.T., L.K., L.M.), BioSiS Department (Department Biologie, Signaux et Systèmes en Cancérologie et Neurosciences), Research Center for Automatic Control of Nancy (CRAN), Lorraine University, CNRS, UMR 7039, Vandoeuvre; and Department of Neurosurgery (S.C.-C.), University Hospital of Nancy, Lorraine University, Nancy, France.
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7
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Mukae N, Shimogawa T, Sakata A, Uehara T, Shigeto H, Yoshimoto K, Morioka T. Reflection of the Ictal Electrocorticographic Discharges Confined to the Medial Temporal Lobe to the Scalp-Recorded Electroencephalogram. Clin EEG Neurosci 2023; 54:173-178. [PMID: 34825584 DOI: 10.1177/15500594211062702] [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] [Indexed: 01/11/2023]
Abstract
Objective: Previous reports on the simultaneous recording of electroencephalography (EEG) and electrocorticography (ECoG) have demonstrated that, in patients with temporal lobe epilepsy (TLE), ictal ECoG discharges with an amplitude as high as 1000 μV originating from the medial temporal lobe could not be recorded on EEG. In contrast, ictal EEG discharges were recorded after ictal ECoG discharges propagated to the lateral temporal lobe. Here, we report a case of TLE in which the ictal EEG discharges, corresponding to ictal ECoG discharges confined to the medial temporal lobe, were recorded. Case report: In the present case, ictal EEG discharges were hardly recognized when the amplitude of the ECoG discharges was less than 1500 μV. During the evolution and burst suppression phase, corresponding to highly synchronized ECoG discharges with amplitudes greater than 1500 to 2000 μV, rhythmic negative waves with the same frequency were clearly recorded both on the lateral temporal lobe and scalp. The amplitude of the lateral temporal ECoG was approximately one-tenth of that of the medial temporal ECoG. The amplitude of the scalp EEG was approximately one-tenth of that of the lateral temporal ECoG. Conclusions: Highly synchronized ictal ECoG discharges with high amplitude of greater than 1500 to 2000 μV in the medial temporal lobe could be recorded on the scalp as ictal EEG discharges via volume conduction.
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Affiliation(s)
- Nobutaka Mukae
- Department of Neurosurgery,Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takafumi Shimogawa
- Department of Neurosurgery,Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ayumi Sakata
- Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, Fukuoka, Japan
| | - Taira Uehara
- Department of Neurology, International University of Health and Welfare Narita Hospital, Narita, Japan
| | - Hiroshi Shigeto
- Division of Medical Technology, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Koji Yoshimoto
- Department of Neurosurgery,Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takato Morioka
- Department of Neurosurgery, 91356Harasanshin Hospital, Fukuoka, Japan
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Yoo JY. BIRDs (Brief Potentially Ictal Rhythmic Discharges) watching during EEG monitoring. Front Neurol 2022; 13:966480. [PMID: 36081872 PMCID: PMC9445572 DOI: 10.3389/fneur.2022.966480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Brief Potentially Ictal Rhythmic Discharges (BIRDs), initially described in neonates, have been shown to correlate with increased risk of seizures in both critically ill and non-critically ill adults. In critically ill patients, BIRDs are associated with acute brain injury and worse functional outcomes. In non-critically ill adults, BIRDs are seen in patients with epilepsy with a greater likelihood of having drug resistance. The location of BIRDs seems to better predict the seizure onset zone compared to other interictal epileptiform discharges. The definition of BIRDs includes Paroxysmal Fast Activity (PFA), and they have similar clinical significance regardless of the exact cut-off frequencies. Their potential as a biomarker for seizure activity and seizure onset zone has been suggested. In patients with status epilepticus, BIRDs also resolve or decrease when seizures resolve. Thus, if BIRDs are observed on scalp EEG, more extended EEG monitoring is recommended to estimate their seizure burden and to guide treatment. With the recent addition of BIRDs in the critical care EEG terminology, with future investigations, we may soon be able to reach a consensus about the definition of electrographic seizures and better understand their neurophysiology and clinical significance.
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9
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Ray J, Wijesekera L, Cirstea S. Machine learning and clinical neurophysiology. J Neurol 2022; 269:6678-6684. [PMID: 35907045 DOI: 10.1007/s00415-022-11283-9] [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: 06/13/2022] [Revised: 07/05/2022] [Accepted: 07/09/2022] [Indexed: 11/29/2022]
Abstract
Clinical neurophysiology constructs a wealth of dynamic information pertaining to the integrity and function of both central and peripheral nervous systems. As with many technological fields, there has been an explosion of data in neurophysiology over recent years, and this requires considerable analysis by experts. Computational algorithms and especially advances in machine learning (ML) have the ability to assist with this task and potentially reveal hidden insights. In this update article, we will provide a brief overview where such technology is being applied in clinical neurophysiology and possible future directions.
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Affiliation(s)
- Julian Ray
- Department of Clinical Neurophysiology, Addenbrooke's Hospital, Cambridge University Hospitals Neurosciences, Cambridge, UK.
| | - Lokesh Wijesekera
- Department of Clinical Neurophysiology, Addenbrooke's Hospital, Cambridge University Hospitals Neurosciences, Cambridge, UK
| | - Silvia Cirstea
- Department of Clinical Neurophysiology, Addenbrooke's Hospital, Cambridge University Hospitals Neurosciences, Cambridge, UK
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10
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Ricci L, Matarrese M, Peters JM, Tamilia E, Madsen JR, Pearl PL, Papadelis C. Virtual implantation using conventional scalp EEG delineates seizure onset and predicts surgical outcome in children with epilepsy. Clin Neurophysiol 2022; 139:49-57. [PMID: 35526353 PMCID: PMC10026594 DOI: 10.1016/j.clinph.2022.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 04/04/2022] [Accepted: 04/08/2022] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Delineation of the seizure onset zone (SOZ) is required in children with drug resistant epilepsy (DRE) undergoing neurosurgery. Intracranial EEG (icEEG) serves as gold standard but has limitations. Here, we examine the utility of virtual implantation with electrical source imaging (ESI) on ictal scalp EEG for mapping the SOZ and predict surgical outcome. METHODS We retrospectively analyzed EEG data from 35 children with DRE who underwent surgery and dichotomized into seizure-free (SF) and non-seizure-free (NSF). We estimated virtual sensors (VSs) at brain locations that matched icEEG implantation and compared ictal patterns at VSs vs icEEG. We calculated the agreement between VSs SOZ and clinically defined SOZ and built receiver operating characteristic (ROC) curves to test whether it predicted outcome. RESULTS Twenty-one patients were SF after surgery. Moderate agreement between virtual and icEEG patterns was observed (kappa = 0.45, p < 0.001). Virtual SOZ agreement with clinically defined SOZ was higher in SF vs NSF patients (66.6% vs 41.6%, p = 0.01). Anatomical concordance of virtual SOZ with clinically defined SOZ predicted outcome (AUC = 0.73; 95% CI: 0.57-0.89; sensitivity = 66.7%; specificity = 78.6%; accuracy = 71.4%). CONCLUSIONS Virtual implantation on ictal scalp EEG can approximate the SOZ and predict outcome. SIGNIFICANCE SOZ mapping with VSs may contribute to tailoring icEEG implantation and predict outcome.
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Affiliation(s)
- Lorenzo Ricci
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, University Campus Bio-Medico of Rome, Rome, Italy
| | - Margherita Matarrese
- Unit of Non-Linear Physics and Mathematical Modelling, Engineering Department, University Campus Bio-Medico of Rome, Rome, Italy; Jane and John Justin Neurosciences Center, Cook Children's Health Care System, Fort Worth, TX, USA; Department of Bioengineering, University of Texas at Arlington, Arlington, TX, USA
| | - Jurriaan M Peters
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Eleonora Tamilia
- Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Joseph R Madsen
- Division of Epilepsy Surgery, Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Phillip L Pearl
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christos Papadelis
- Jane and John Justin Neurosciences Center, Cook Children's Health Care System, Fort Worth, TX, USA; Department of Bioengineering, University of Texas at Arlington, Arlington, TX, USA; School of Medicine, Texas Christian University, Fort Worth, TX, USA.
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11
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Wei Zhang VJ, Jackson G, Fitt G, Perchyonok Y, Vaughan DN. Seizure Duration and Spread Dynamics in MRI-Defined Subtypes of Temporal Lobe Epilepsy. Neurology 2022; 99:e355-e363. [PMID: 35508399 DOI: 10.1212/wnl.0000000000200354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 02/21/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES MR and PET imaging enables subgroups of Temporal Lobe Epilepsy (TLE) to be defined on the basis of structural pathology. Few studies have examined the variation in electroclinical seizure spread patterns based on imaging findings. We performed a retrospective cohort study, to investigate the electroclinical differences between three specific groups of TLE: MRI-negative PET-positive TLE (MRI-neg TLE), temporal lobe lesion TLE (Lesional TLE) and unilateral hippocampal sclerosis TLE (HS-TLE). METHODS Patients with an electroclinical diagnosis of TLE who had video-scalp EEG recordings of seizures, were identified from the retrospective database of the Austin Comprehensive Epilepsy Program between 2005 and 2019. The cohort was further selected into the three defined groups based on imaging findings, using MRI and FDG-PET. Timings of clinical and electrographic seizure progression were measured, considering the onset, ipsilateral lobar spread, contralateral spread and termination. Durations were compared between groups using linear mixed models with inclusion of demographic and clinical covariates. RESULTS A total of 105 patients (137 seizures) were included, comprising 36 with MRI-neg TLE (54 seizures), 36 with Lesional TLE (18 lateral versus 16 mesial lesions; 44 seizures) and 33 with HS-TLE (39 seizures). Seizure duration was similar between MRI-neg TLE and Lesional TLE (mean 75.9 vs 71.7 seconds, p=0.91). Further dividing Lesional TLE into medial versus lateral temporal revealed no timing difference either. However, the HS-TLE group had longer total seizure duration (114 seconds) compared to both MRI-neg TLE (p<0.001) and Lesional TLE (p<0.001). Progression of electrographic spread also reflected this pattern, with involvement of extra-temporal regions and then the contralateral hemisphere each taking significantly longer in HS-TLE. DISCUSSION MRI-neg TLE appears electrographically similar to Lesional TLE, whether mesial or lateral, in the duration of seizures and the timing of electrographic spread. Both appear electrographically different from HS-TLE where propagation is slower, suggesting engagement of different epileptogenic networks or seizure suppression mechanisms. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that the electroclinical features of seizures in HS-TLE are different than MRI-neg TLE and lesional TLE.
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Affiliation(s)
- Victor Jia Wei Zhang
- Department of Neurology, Austin Hospital, Heidelberg, Victoria, Australia .,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia
| | - Graeme Jackson
- Department of Neurology, Austin Hospital, Heidelberg, Victoria, Australia.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia
| | - Greg Fitt
- Department of Radiology, Austin Hospital, Heidelberg, Victoria, Australia.,University of Melbourne, Parkville, Victoria, Australia
| | - Yuliya Perchyonok
- Department of Radiology, Austin Hospital, Heidelberg, Victoria, Australia.,University of Melbourne, Parkville, Victoria, Australia
| | - David Noel Vaughan
- Department of Neurology, Austin Hospital, Heidelberg, Victoria, Australia.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia
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12
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Casale MJ, Marcuse LV, Young JJ, Jette N, Panov FE, Bender HA, Saad AE, Ghotra RS, Ghatan S, Singh A, Yoo JY, Fields MC. The Sensitivity of Scalp EEG at Detecting Seizures-A Simultaneous Scalp and Stereo EEG Study. J Clin Neurophysiol 2022; 39:78-84. [PMID: 32925173 PMCID: PMC8290181 DOI: 10.1097/wnp.0000000000000739] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PURPOSE Compare the detection rate of seizures on scalp EEG with simultaneous intracranial stereo EEG (SEEG) recordings. METHODS Twenty-seven drug-resistant epilepsy patients undergoing SEEG with simultaneous scalp EEG as part of their surgical work-up were included. A total of 172 seizures were captured. RESULTS Of the 172 seizures detected on SEEG, 100 demonstrated scalp ictal patterns. Focal aware and subclinical seizures were less likely to be seen on scalp, with 33% of each observed when compared with focal impaired aware (97%) and focal to bilateral tonic-clonic seizures (100%) (P < 0.001). Of the 72 seizures without ictal scalp correlate, 32 demonstrated an abnormality during the SEEG seizure that was identical to an interictal abnormality. Seizures from patients with MRI lesions were statistically less likely to be seen on scalp than seizures from nonlesional patients (P = 0.0162). Stereo EEG seizures not seen on scalp were shorter in duration (49 seconds) compared with SEEG seizures seen on scalp (108.6 seconds) (P < 0.001). CONCLUSIONS Scalp EEG is not a sensitive tool for the detection of focal aware and subclinical seizures but is highly sensitive for the detection of focal impaired aware and focal to bilateral tonic-clonic seizures. Longer duration of seizure and seizures from patients without MRI lesions were more likely to be apparent on scalp. Abnormalities seen interictally may at times represent an underlying seizure. The cognitive, affective, and behavioral long-term effects of ongoing difficult-to-detect seizures are not known.
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Affiliation(s)
- Marc J. Casale
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Lara V. Marcuse
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - James J. Young
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Nathalie Jette
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Fedor E. Panov
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - H. Allison Bender
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Adam E. Saad
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Ravi S. Ghotra
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Saadi Ghatan
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Anuradha Singh
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Ji Yeoun Yoo
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
| | - Madeline C. Fields
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, U.S.A
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13
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Frazzini V, Cousyn L, Navarro V. Semiology, EEG, and neuroimaging findings in temporal lobe epilepsies. HANDBOOK OF CLINICAL NEUROLOGY 2022; 187:489-518. [PMID: 35964989 DOI: 10.1016/b978-0-12-823493-8.00021-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy. First descriptions of TLE date back in time and detailed portraits of epileptic seizures of temporal origin can be found in early medical reports as well as in the works of various artists and dramatists. Depending on the seizure onset zone, several subtypes of TLE have been identified, each one associated with peculiar ictal semiology. TLE can result from multiple etiological causes, ranging from genetic to lesional ones. While the diagnosis of TLE relies on detailed analysis of clinical as well as electroencephalographic (EEG) features, the lesions responsible for seizure generation can be highlighted by multiple brain imaging modalities or, in selected cases, by genetic investigations. TLE is the most common cause of refractory epilepsy and despite the great advances in diagnostic tools, no lesion is found in around one-third of patients. Surgical treatment is a safe and effective option, requiring presurgical investigations to accurately identify the seizure onset zone (SOZ). In selected cases, presurgical investigations need intracerebral investigations (such as stereoelectroencephalography) or dedicated metabolic imaging techniques (interictal PET and ictal SPECT) to correctly identify the brain structures to be removed.
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Affiliation(s)
- Valerio Frazzini
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France
| | - Louis Cousyn
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France
| | - Vincent Navarro
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France.
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14
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Sakata A, Mukae N, Morioka T, Tanaka S, Shimogawa T, Shigeto H, Hotta T, Kang D, Mizoguchi M. Simultaneous Electroencephalographic and Electocorticographic Recordings of Lateralized Periodic Discharges in Temporal Lobe Epilepsy. Clin EEG Neurosci 2022; 53:61-69. [PMID: 33172294 DOI: 10.1177/1550059420972266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Lateralized periodic discharges (LPDs), which constitute an abnormal electroencephalographic (EEG) pattern, are most often observed in critically ill patients with acute pathological conditions, and are less frequently observed in chronic conditions such as focal epilepsies, including temporal lobe epilepsy (TLE). Here we aim to explore the pathophysiological mechanism of LPD in TLE. METHODS We retrospectively selected 3 patients with drug-resistant TLE who simultaneously underwent EEG and electrocorticography (ECoG) and demonstrated LPDs. We analyzed the correlation between the EEG and ECoG findings. RESULTS In patients 1 and 2, LPDs were recorded in the temporal region of the scalp during the interictal periods, when repeated spikes followed by slow waves (spike-and-wave complexes; SWs) and periodic discharges (PDs) with amplitudes of >600 to 800 µV appeared in the lateral temporal lobe over a cortical area of >10 cm2. In patient 3, when the ictal discharges persisted and were confined to the medial temporal lobe, repeated SWs were provoked on the lateral temporal lobe. When repeated SWs with amplitudes of >800 µV appeared in an area of the lateral temporal lobe of >10 cm2, the corresponding EEG discharges appeared on the temporal scalp. CONCLUSIONS LPDs in patients with TLE originate from repeated SWs and PDs of the lateral temporal lobe, which might represent a highly irritable state of the lateral temporal cortex during both interictal and ictal periods.
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Affiliation(s)
- Ayumi Sakata
- Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, Fukuoka, Japan
| | - Nobutaka Mukae
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takato Morioka
- Department of Neurosurgery, Harasanshin Hospital, Fukuoka, Japan
| | - Shunya Tanaka
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takafumi Shimogawa
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hiroshi Shigeto
- Division of Medical Technology, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Taeko Hotta
- Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, Fukuoka, Japan
| | - Dongchong Kang
- Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, Fukuoka, Japan
| | - Masahiro Mizoguchi
- Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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15
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Highly consistent temporal lobe interictal spike networks revealed from foramen ovale electrodes. Clin Neurophysiol 2021; 132:2065-2074. [PMID: 34284241 DOI: 10.1016/j.clinph.2021.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 11/22/2022]
Abstract
OBJECTIVE A major challenge that limits understanding and treatment of epileptic events from mesial temporal structures comes from our inability to detect and map interictal networks reproducibly using scalp electrodes. Here, we developed a novel approach to map interictal spike networks and demonstrate their relationships to seizure onset and lesions in patients with foramen ovale electrode implantations. METHODS We applied the direct Directed Transfer Function to reveal interictal spike propagation from bilateral foramen ovale electrodes on 10 consecutive patients and co-registered spatially with both seizure onset zones and temporal lobe lesions. RESULTS Highly reproducible, yet unique interictal spike networks were seen for each patient (correlation: 0.93 ± 0.13). Interictal spikes spread in both anterior and posterior directions within each temporal lobe, often reverberating between sites. Spikes propagated to the opposite temporal lobe predominantly through posterior pathways. Patients with structural lesions (N = 4), including tumors and sclerosis, developed reproducible spike networks adjacent to their lesions that were highly lateralized compared to patients without lesions. Only 5% of mesial temporal lobe spikes were time-locked with scalp electrode spikes. Our preliminary observation on two lesional patients suggested that along with lesion location, Interictal spike networks also partially co-registered with seizure onset zones suggesting interrelationship between seizure onset and a subset of spike networks. CONCLUSIONS This is the first demonstration of patient-specific, reproducible interictal spike networks in mesial temporal structures that are closely linked to both temporal lobe lesions and seizure onset zones. SIGNIFICANCE Interictal spike connectivity is a novel approach to map epileptic networks that could help advance invasive and non-invasive epilepsy treatments.
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16
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Hasegawa D, Asada R, Hamamoto Y, Yu Y, Kuwabara T, Mizoguchi S, Chambers JK, Uchida K. Focal Cortical Resection and Hippocampectomy in a Cat With Drug-Resistant Structural Epilepsy. Front Vet Sci 2021; 8:719455. [PMID: 34355038 PMCID: PMC8329420 DOI: 10.3389/fvets.2021.719455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/25/2021] [Indexed: 11/13/2022] Open
Abstract
Epilepsy surgery is a common therapeutic option in humans with drug-resistant epilepsy. However, there are few reports of intracranial epilepsy surgery for naturally occurring epilepsy in veterinary medicine. A 12-year-old neutered male domestic shorthair cat with presumed congenital cortical abnormalities (atrophy) in the right temporo-occipital cortex and hippocampus had been affected with epilepsy from 3 months of age. In addition to recurrent epileptic seizures, the cat exhibited cognitive dysfunction, bilateral blindness, and right forebrain signs. Seizures had been partially controlled (approximately 0.3–0.7 seizures per month) by phenobarbital, zonisamide, diazepam, and gabapentin until 10 years of age; however, they gradually became uncontrollable (approximately 2–3 seizures per month). In order to plan epilepsy surgery, presurgical evaluations including advanced structural magnetic resonance imaging and long-term intracranial video-electroencephalography monitoring were conducted to identify the epileptogenic zone. The epileptogenic zone was suspected in the right atrophied temporo-occipital cortex and hippocampus. Two-step surgery was planned, and a focal cortical resection of that area was performed initially. After the first surgery, seizures were not observed for 2 months, but they then recurred. The second surgery was performed to remove the right atrophic hippocampus and extended area of the right cortex, which showed spikes on intraoperative electrocorticography. After the second operation, although epileptogenic spikes remained in the contralateral occipital lobe, which was suspected as the second epileptogenic focus, seizure frequency decreased to <0.3 seizure per month under treatment with antiseizure drugs at 1.5 years after surgery. There were no apparent complications associated with either operation, although the original neurological signs were unchanged. This is the first exploratory study of intracranial epilepsy surgery for naturally occurring epilepsy, with modern electroclinical and imaging evidence, in veterinary medicine. Along with the spread of advanced diagnostic modalities and neurosurgical devices in veterinary medicine, epilepsy surgery may be an alternative treatment option for drug-resistant epilepsy in cats.
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Affiliation(s)
- Daisuke Hasegawa
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan.,The Research Center of Animal Life Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Rikako Asada
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yuji Hamamoto
- Veterinary Medical Teaching Hospital, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yoshihiko Yu
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Takayuki Kuwabara
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Shunta Mizoguchi
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - James K Chambers
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Japan
| | - Kazuyuki Uchida
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Japan
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17
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Andrade-Machado R, Benjumea Cuartas V, Muhammad IK. Recognition of interictal and ictal discharges on EEG. Focal vs generalized epilepsy. Epilepsy Behav 2021; 117:107830. [PMID: 33639439 DOI: 10.1016/j.yebeh.2021.107830] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/23/2021] [Accepted: 01/26/2021] [Indexed: 01/17/2023]
Abstract
INTRODUCTION The differentiation between focal and generalized epilepsies based on clinical and electroencephalographic features is difficult and sometimes confusing. OBJECTIVE To review the EEG findings in patients with focal epilepsy. METHODS An extensive literature review was done. We used the following Pubmed and Medline descriptors alone and in different combinations for database searching: focal, partial, epilepsy, electroencephalographic findings, and EEG. Additional filters included review, original articles, and language limited to Spanish and English. Using the above criteria, a total of 69 articles showed the interictal and ictal EEG findings in focal epilepsy. DEVELOPMENT Focal epileptiform discharges and persistence of focal abnormalities, characterize the interictal EEG findings in focal epilepsies. To distinguish SBS from primary generalized spike waves are required to note: (a) a lead-in time of at least 2 s, (b) the morphology of the focal triggering spikes clearly differ from that of the bisynchronous epileptiform paroxysms, and (c) the morphology of triggering spikes resemble that of other focal spikes from the same region. Focal and Generalized Epilepsy can coexist. Delayed Lateralization on EEG with inconclusive onset and bizarre semiology confusing semiology should not be confused with generalized onset seizures with focal evolution. CONCLUSIONS A close attention to localization and morphology of epileptiform discharges, the correct interpretation of secondary bilateral synchrony, and provocative maneuvers help to correctly identify the EEG findings leading to diagnose focal epilepsies. The presence of generalized epileptiform activity does not rule out the existence of a focal epilepsy.
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18
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Itabashi I, Jin K, Sato S, Suzuki H, Iwasaki M, Kitazawa Y, Kakisaka Y, Nakasato N. Initial delta and delayed theta/alpha pattern in the temporal region on ictal EEG suggests purely hippocampal epileptogenicity in patients with mesial temporal lobe epilepsy. Clin Neurophysiol 2021; 132:737-743. [PMID: 33561726 DOI: 10.1016/j.clinph.2020.11.041] [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: 06/10/2020] [Revised: 11/14/2020] [Accepted: 11/24/2020] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine whether the ictal scalp EEG findings suggest purely hippocampal epileptogenicity in patients with mesial temporal lobe epilepsy (mTLE) associated with hippocampal sclerosis (HS). METHODS Twenty-three patients with mTLE with pathologically confirmed HS were divided into 12 with epileptogenicity only in the hippocampus (HS only group) and 11 with epileptogenicity in both the hippocampus and temporal neocortex or other locations (HS plus group), based on the combination of surgical procedures, postoperative outcome, and pathological findings. Sixteen underwent selective amygdalohippocampectomy (SelAH) and 7 received anterior temporal lobectomy. Ictal scalp EEG findings of 79 focal impaired awareness seizures were compared between the HS only and HS plus groups. We focused on the 1-4 Hz rhythmic delta activity at ictal onset followed by 5-9 Hz rhythmic theta/alpha activity 10-30 s after the onset in the temporal region. RESULTS The initial delta and delayed theta/alpha (ID-DT) pattern was observed in 8 of 12 patients in the HS only group, but in none of 11 patients in the HS plus group (p < 0.01). CONCLUSIONS ID-DT pattern on ictal EEG suggests purely hippocampal epileptogenicity in mTLE with HS. SIGNIFICANCE Patients with the ID-DT pattern are likely to become seizure-free after SelAH.
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Affiliation(s)
- Izumi Itabashi
- Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Kazutaka Jin
- Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
| | - Shiho Sato
- Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Hiroyoshi Suzuki
- Department of Pathology, National Hospital Organization Sendai Medical Center, Sendai, Miyagi, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan; Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Yu Kitazawa
- Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Yosuke Kakisaka
- Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Nobukazu Nakasato
- Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
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Abstract
BACKGROUND Patients with temporal lobe epilepsy (TLE) originating from different seizure onset zones had distinct electrophysiological characteristics and surgical outcomes. In this study, we aimed to investigate the relationship between the origin and prognosis of TLE, and the stereoelectroencephalography (SEEG) features. METHODS Thirty patients with TLE, who underwent surgical treatment in our functional neurosurgery department from January 2016 to December 2017, were enrolled in this study. All patients underwent anterior temporal lobectomy after an invasive pre-operative evaluation with SEEG. Depending on the epileptic focus location, patients were divided into those with medial temporal lobe seizures (MTLS) and those with lateral temporal lobe seizures (LTLS). The Engel classification was used to evaluate operation effectiveness, and the Kaplan-Meier analysis was used to detect seizure-free duration. RESULTS The mean follow-up time was 25.7 ± 4.8 months. Effectiveness was 63.3% for Engel I (n = 19), 13.3% for Engel II, 3.3% for Engel III, and 20.0% for Engel IV. According to the SEEG, 60.0% (n = 18) had MTLS, and 40.0% (n = 12) had LTLS. Compared with the MTLS group, the operation age of those with LTLS was significantly greater (26.9 ± 6.9 vs. 29.9 ± 12.5 years, t = -0.840, P = 0.009) with longer epilepsy duration (11.9 ± 6.0 vs. 17.9 ± 12.1 years, t = -1.801, P = 0.038). Patients with MTLS had a longer time interval between ictal onset to seizure (67.3 ± 59.1 s vs. 29.3 ± 24.4 s, t = 2.017, P = 0.008). The most common SEEG ictal pattern was a sharp/spike-wave rhythm in the MTLS group (55.6%) and low-voltage fast activity in the LTLS group (58.3%). Compared with the LTLS group, patients with MTLS had a more favorable prognosis (41.7% vs. 77.8%, P = 0.049). Post-operative recurrence was more likely to occur within three months after the operation for both groups, and there appeared to be a stable long-term outcome. CONCLUSION Patients with MTLS, who accounted for three-fifths of patients with TLE, showed a more favorable surgical outcome.
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20
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Morano A, Fanella M, Cerulli Irelli E, Barone FA, Fisco G, Orlando B, Albini M, Fattouch J, Manfredi M, Casciato S, Di Gennaro G, Giallonardo AT, Di Bonaventura C. Seizures in autoimmune encephalitis: Findings from an EEG pooled analysis. Seizure 2020; 83:160-168. [PMID: 33161244 DOI: 10.1016/j.seizure.2020.10.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/14/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Seizures are common in autoimmune encephalitis (AE), and an extensive work-up is required to exclude alternative etiologies. The aim of our study was to identify possible clinical/EEG peculiarities suggesting the immune-mediated origin of late-onset seizures. METHODS Thirty patients diagnosed with AE (19 men, median age 68 years, 18 seronegative) were included. Overall 212 video-electroencephalographic (EEG) and 31 24-h ambulatory EEG (AEEG) recordings were retrospectively reviewed. Posterior dominant rhythm, interictal epileptiform discharges (IEDs), clinical (CSs) and subclinical seizures (SCSs) were analyzed. RESULTS Six-hundred-nineteen ictal events were recorded in 19/30 subjects, mostly (568/619) during AE acute stage. Among ten patients with CSs other than faciobrachial dystonic seizures, 7 showed prominent autonomic and emotional manifestations. SCSs were detected in 11 subjects, mainly via AEEG (260/287 SCSs vs 150/332 CSs, p < 0.001). Eight patients presented seizures during hyperventilation. IEDs, documented in 21 cases, were bilateral in 14 and focal temporal in 13. Multiple ictal EEG patterns were detected in 9/19 patients, 6 of whom had both CSs and SCSs, bilateral asynchronous seizures and ictal activities arising from temporal and extra-temporal regions. No correlation was found between the lateralization of MRI alterations and that of EEG findings. CONCLUSION Our study confirms that adult-onset, high frequency focal seizures with prominent autonomic and emotional manifestations should be investigated for AE. Multiple ictal EEG patterns could represent a 'red flag', reflecting a widespread neuronal excitability related to the underlying immune-mediated process. Finally, our work enhances the crucial role of long-lasting EEG monitoring in revealing subclinical and relapsing seizures.
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Affiliation(s)
- Alessandra Morano
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | - Martina Fanella
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy; Neurology Unit, "San Camillo de' Lellis" General Hospital, Rieti, Italy
| | - Emanuele Cerulli Irelli
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | - Francesca A Barone
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | - Giacomo Fisco
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | - Biagio Orlando
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | | | - Jinane Fattouch
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | - Mario Manfredi
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | - Sara Casciato
- Epilepsy Surgery Unit, IRCCS "Neuromed", Pozzilli, IS, Italy
| | | | - Anna Teresa Giallonardo
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy
| | - Carlo Di Bonaventura
- Epilepsy Unit, Department of Human Neurosciences, "Sapienza" University of Rome, Rome, Italy.
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21
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Heers M, Reinacher PC, Scheiwe C, Schulze-Bonhage A, Altenmüller DM. Distinct ictal hippocampal sharp transients in scalp EEG. Clin Neurophysiol 2020; 131:1925-1927. [DOI: 10.1016/j.clinph.2020.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 10/24/2022]
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22
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Palepu A, Li A, Fitzgerald Z, Hu K, Costacurta J, Bulacio J, Martinez-Gonzalez J, Sarma SV. Evaluating Invasive EEG Implantations with Structural Imaging Data and Functional Scalp EEG Recordings from Epilepsy Patients. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:3866-3869. [PMID: 31946717 DOI: 10.1109/embc.2019.8857241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Seizures in patients with medically refractory epilepsy (MRE) cannot be controlled with drugs. For focal MRE, seizures originate in the epileptogenic zone (EZ), which is the minimum amount of cortex that must be treated to be seizure free. Localizing the EZ is often a laborious process wherein clinicians first inspect scalp EEG recordings during several seizure events, and then formulate an implantation plan for subsequent invasive monitoring. The goal of implantation is to place electrodes into the brain region covering the EZ. Then, during invasive monitoring, clinicians visually inspect intracranial EEG recordings to more precisely localize the EZ. Finally, the EZ is then surgically ablated, removed or treated with electrical stimulation. Unfortunately success rates average at 50%. Such grim outcomes call for analytical assistance in creating more accurate implantation plans from scalp EEG. In this paper, we introduce a method that combines imaging data (CT and MRI scans) with scalp EEG to derive an implantation distribution. Specifically, scalp EEG data recorded over a seizure event is converted into a time-gamma frequency map, which is then processed to derive a spectrally annotated implantation distribution (SAID). The SAID represents a distribution of gamma power in each of eight cortical lobe/hemisphere partitions. We applied this method to 4 MRE patients who underwent treatment, and found that the SAID distribution overlapped more with clinical implantations in success cases than in failed cases. These preliminary findings suggest that the SAID may help in improving EZ localization accuracy and surgical outcomes.
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23
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Quigg M, Skarpaas TL, Spencer DC, Fountain NB, Jarosiewicz B, Morrell MJ. Electrocorticographic events from long-term ambulatory brain recordings can potentially supplement seizure diaries. Epilepsy Res 2020; 161:106302. [PMID: 32126490 DOI: 10.1016/j.eplepsyres.2020.106302] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/11/2020] [Accepted: 02/22/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE To determine the feasibility of using epileptiform events detected by continuous electrocorticographic monitoring via a brain-responsive neurostimulation system to supplement patient-maintained seizure diaries. METHODS Data were retrospectively analyzed from a randomized controlled trial of brain-responsive neurostimulation (RNS® System) for adjunctive treatment of medically intractable focal onset seizures in 191 subjects. The long-term (≥3 months) correspondence between daily counts of diary-reported seizures and device-recorded "long epileptiform events" (LEs), a proxy for electrographic seizures (ESs), was assessed using cross-correlation and logistic generalized estimating equation models. RESULTS Diary-reported seizures and LEs significantly co-varied across days in 124 patients whose detection settings were held constant, with a significantly higher correlation in 54 patients (44 %) whose LEs were usually ESs (high concordance patients). There were more days in which LEs were detected than days in which patients reported a seizure (positive predictive value (PPV): 34 %). On days when there were no LEs, there were typically no diary-reported seizures (negative predictive value (NPV): 90 %). In patients with a high concordance between LEs and ESs, the PPV and NPV were both slightly higher, 43 % (35-52 %) and 93 % (95 % CI: 86-97 %) respectively. CONCLUSION Although LEs can substantially outnumber diary reported seizures, the high across-day correlation and strong NPV between LEs and diary seizures suggests that LEs recorded by the RNS® System could potentially supplement seizure diaries by providing an objective biomarker for relative seizure burden.
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Affiliation(s)
- Mark Quigg
- FE Dreifuss Comprehensive Epilepsy Program, Dept Neurology, University of Virginia, Charlottesville, VA, USA.
| | | | - David C Spencer
- Dept Neurology, Oregon Health & Science University, Portland, OR, USA
| | - Nathan B Fountain
- FE Dreifuss Comprehensive Epilepsy Program, Dept Neurology, University of Virginia, Charlottesville, VA, USA
| | | | - Martha J Morrell
- NeuroPace, Inc, Mountain View, CA, USA; Dept Neurology, Stanford University, Stanford, CA, USA
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24
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Abstract
PURPOSE OF REVIEW Epilepsy is a heterogeneous disorder that is often associated with abnormal electroencephalogram (EEG) findings. This article provides an overview of common EEG findings in epileptic disorders. The physiologic basis of EEG and intracranial EEG studies is also discussed. RECENT FINDINGS EEG is widely used in clinical practice. Because of the paroxysmal nature of seizure disorders, interictal epileptiform discharges, such as spikes and sharp waves, are often used to support the diagnosis of epilepsy when a habitual seizure is not captured by EEG. Interictal and ictal EEG findings also underlie the classification of seizures and epilepsy. Continuous critical care EEG monitoring has become an invaluable study in the diagnosis and treatment of subclinical seizures and nonconvulsive status epilepticus. Intracranial EEG with subdural or intraparenchymal electrodes is warranted when localization of the seizure focus and mapping of eloquent brain areas are required to plan epilepsy surgery. SUMMARY The EEG is a key tool in the diagnosis of epilepsy. Interictal and ictal EEG findings are crucial for the confirmation and classification of seizure disorders. Intracranial EEG monitoring is also indispensable for planning surgery for some patients.
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25
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Permutation entropy in intraoperative ECoG of brain tumour patients in awake tumour surgery- a robust parameter to separate consciousness from unconsciousness. Sci Rep 2019; 9:16482. [PMID: 31712616 PMCID: PMC6848144 DOI: 10.1038/s41598-019-52949-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 10/25/2019] [Indexed: 01/10/2023] Open
Abstract
Awake craniotomies represent an essential opportunity in the case of lesions in eloquent areas. Thus, optimal surveillance of the patient during different stages of sedation, as well as the detection of seizure activity during brain surgery, remains difficult, as skin electrodes for electroencephalographic (EEG) analysis are not applicable in most cases. We assessed the applicability of ECoG to monitor different stages of sedation, as well as the influence of different patient characteristics, such as tumour volume, size, entity, and age or gender on permutation entropy (PeEn). We conducted retrospective analysis of the ECoG data of 16 patients, who underwent awake craniotomies because of left-sided brain tumours at our centre between 2014 and 2016. PeEn could be easily calculated and compared using frontal and parietal cortical electrodes. A comparison of PeEn scores showed significantly higher values in awake patients than in patients under anaesthesia (p ≤ 0.004) and significantly higher ones in the state of transition than under general anaesthesia (p = 0.023). PeEn scores in frontal and parietal leads did not differ significantly, making them both applicable for continuous surveillance during brain surgery. None of the following clinical characteristics showed significant correlation with PeEn scores: tumour volume, WHO grade, first or recurrent tumour, gender, and sex. Being 50 years or older led to significantly lower values in parietal leads but not in frontal leads. ECoG and a consecutive analysis of PeEn are feasible and suitable for the continuous surveillance of patients during awake craniotomies. Hence, the analysis is not influenced by patients' clinical characteristics.
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26
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Weisdorf S, Duun-Henriksen J, Kjeldsen MJ, Poulsen FR, Gangstad SW, Kjaer TW. Ultra-long-term subcutaneous home monitoring of epilepsy-490 days of EEG from nine patients. Epilepsia 2019; 60:2204-2214. [PMID: 31608435 PMCID: PMC6899579 DOI: 10.1111/epi.16360] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/11/2019] [Accepted: 09/11/2019] [Indexed: 02/04/2023]
Abstract
Objective To explore the feasibility of home monitoring of epilepsy patients with a novel subcutaneous electroencephalography (EEG) device, including clinical implications, safety, and compliance via the first real‐life test. Methods We implanted a beta‐version of the 24/7 EEG SubQ (UNEEG Medical A/S, Denmark) subcutaneously in nine participants with temporal lobe epilepsy. Data on seizures, adverse events, compliance in using the device, and use of antiepileptic drugs (AEDs) were collected. EEG was recorded for up to 3 months, and all EEG data were reviewed visually to identify electrographic seizures. These were descriptively compared to seizure counts and AED changes reported in diaries from the same period. Results Four hundred ninety days of EEG and 338 electrographic seizures were collected. Eight participants completed at least 9 weeks of home monitoring, while one cancelled participation after 4 weeks due to postimplantation soreness. In total, 13 cases of device‐related adverse events were registered, none of them serious. Recordings obtained from the device covered 73% of the time, on average (range 45%‐91%). Descriptively, electrographic seizure counts were substantially different from diary seizure counts. We uncovered several cases of underreporting and revealed important information on AED response. Electrographic seizure counts revealed circadian distributions of seizures not visible from seizure diaries. Significance The study shows that home monitoring for up to 3 months with a subcutaneous EEG device is feasible and well tolerated. No serious adverse device‐related events were reported. An objective seizure count can be derived, which often differs substantially from self‐reported seizure counts. Larger clinical trials quantifying the benefits of objective seizure counting should be a priority for future research as well as development of algorithms for automated review of data.
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Affiliation(s)
- Sigge Weisdorf
- Department of Neurology, Zealand University Hospital, Roskilde, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Duun-Henriksen
- UNEEG Medical A/S, Lynge, Denmark.,Department of Basic and Clinical Neuroscience, King's College London, London, UK
| | - Marianne J Kjeldsen
- Department of Neurology, Odense University Hospital, Odense, Denmark.,Clinical Institute, University of Southern Denmark, Odense, Denmark
| | - Frantz R Poulsen
- Clinical Institute, University of Southern Denmark, Odense, Denmark.,Department of Neurosurgery, Odense University Hospital, Odense, Denmark
| | - Sirin W Gangstad
- UNEEG Medical A/S, Lynge, Denmark.,Department of Applied Mathematics and Computer Science, Technical University of Denmark, Lyngby, Denmark
| | - Troels W Kjaer
- Department of Neurology, Zealand University Hospital, Roskilde, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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27
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Lam AD, Cole AJ, Cash SS. New Approaches to Studying Silent Mesial Temporal Lobe Seizures in Alzheimer's Disease. Front Neurol 2019; 10:959. [PMID: 31551916 PMCID: PMC6737997 DOI: 10.3389/fneur.2019.00959] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 08/20/2019] [Indexed: 12/13/2022] Open
Abstract
Silent seizures were discovered in mouse models of Alzheimer's disease over 10 years ago, yet it remains unclear whether these seizures are a salient feature of Alzheimer's disease in humans. Seizures that arise early in the course of Alzheimer's disease most likely originate from the mesial temporal lobe, one of the first structures affected by Alzheimer's disease pathology and one of the most epileptogenic regions of the brain. Several factors greatly limit our ability to identify mesial temporal lobe seizures in patients with Alzheimer's disease, however. First, mesial temporal lobe seizures can be difficult to recognize clinically, as their accompanying symptoms are often subtle or even non-existent. Second, electrical activity arising from the mesial temporal lobe is largely invisible on the scalp electroencephalogram (EEG), the mainstay of diagnosis for epilepsy in this population. In this review, we will describe two new approaches being used to study silent mesial temporal lobe seizures in Alzheimer's disease. We will first describe the methodology and application of foramen ovale electrodes, which captured the first recordings of silent mesial temporal lobe seizures in humans with Alzheimer's disease. We will then describe machine learning approaches being developed to non-invasively identify silent mesial temporal lobe seizures on scalp EEG. Both of these tools have the potential to elucidate the role of silent seizures in humans with Alzheimer's disease, which could have important implications for early diagnosis, prognostication, and development of targeted therapies for this population.
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Affiliation(s)
- Alice D. Lam
- Massachusetts General Hospital, Department of Neurology, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Andrew J. Cole
- Massachusetts General Hospital, Department of Neurology, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Sydney S. Cash
- Massachusetts General Hospital, Department of Neurology, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
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28
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Liu X, Wu S, Daif A, Sun T, Chauhan V, Issa NP, Rose S, Tao JX. Clinical implications of scalp ictal EEG pattern in patients with temporal lobe epilepsy. Clin Neurophysiol 2019; 130:1604-1610. [DOI: 10.1016/j.clinph.2019.05.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 04/13/2019] [Accepted: 05/18/2019] [Indexed: 11/16/2022]
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29
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Driver J, DiRisio AC, Mitchell H, Threlkeld ZD, Gormley WB. Non-electrographic Seizures Due to Subdural Hematoma: A Case Series and Review of the Literature. Neurocrit Care 2019; 30:16-21. [PMID: 29476391 DOI: 10.1007/s12028-018-0503-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Seizures due to subdural hematoma (SDH) are a common finding, typically diagnosed using electroencephalography (EEG). At times, aggressive management of seizures is necessary to improve neurologic recovery and outcomes. Here, we present three patients who had undergone emergent SDH evacuation and showed postoperative focal deficits without accompanying electrographic epileptiform activity. After infarction and recurrent hemorrhage were ruled out, seizures were suspected despite a negative EEG. Patients were treated aggressively with AEDs and eventually showed clinical improvement. Long-term monitoring with EEG revealed electrographic seizures in a delayed fashion. EEG recordings are an important tool for seizure detection, but should be used as an adjunct to, rather than a replacement for, the clinical examination in the acute setting. At times, aggressive treatment of suspected postoperative seizures is warranted despite lack of corresponding electrographic activity and can improve clinical outcomes.
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Affiliation(s)
- Joseph Driver
- Department of Neurosurgery, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Aislyn C DiRisio
- Department of Neurosurgery, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Heidi Mitchell
- Massachusetts General Hospital Institute of Health Professions, Boston, MA, USA
| | - Zachary D Threlkeld
- Department of Neurology, Massachusetts General Hospital and Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - William B Gormley
- Department of Neurosurgery, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.
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30
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Bateman LM, Mendiratta A, Liou JY, Smith EJ, Bazil CW, Choi H, McKhann GM, Pack A, Srinivasan S, Schevon CA. Postictal clinical and electroencephalographic activity following intracranially recorded bilateral tonic-clonic seizures. Epilepsia 2019; 60:74-84. [PMID: 30577077 PMCID: PMC6400590 DOI: 10.1111/epi.14621] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/19/2018] [Accepted: 11/20/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The dynamics of the postictal period, which may demonstrate such dramatic clinical phenomena as focal neurological deficits, prolonged coma and immobility, and even sudden death, are poorly understood. We sought to classify and characterize postictal phases of bilateral tonic-clonic seizures based on electroencephalographic (EEG) criteria and associated clinical features. METHODS We performed a detailed electroclinical evaluation of the postictal period in a series of 31 bilateral tonic-clonic seizures in 16 patients undergoing epilepsy surgery evaluations for focal pharmacoresistant epilepsy with intracranial electrodes and time-locked video. RESULTS The postictal EEG demonstrated three clearly differentiated phases as follows: attenuation, a burst-attenuation pattern, and a return to continuous background, with abrupt, synchronized transitions between phases. Postictal attenuation was common, occurring in 84% of seizures in 94% of patients in this study. There was increased power in gamma frequencies (>25 Hz) during postictal attenuation periods relative to preictal baseline in 88% of seizures demonstrating the attenuation pattern (n = 25 seizures, P < 0.002). Such increases were seen in >90% of channels in 13 seizures (52%) and <10% of channels in three seizures (12%). Postictal immobility was seen in 87% of seizures, with either a flaccid (58%) or rigid/dystonic (29%) appearance. Clinical motor manifestations, including focal dystonic posturing, automatisms, head and eye deviation, and myoclonic jerking, continued or emerged within the first minute following seizure termination in 48% of seizures, regardless of EEG appearance. SIGNIFICANCE Intracranial postictal attenuation, which may be diffuse or focal, is so common that it should be regarded as a ubiquitous feature of bilateral tonic-clonic seizures, rather than an unusual event. The prominence of high-frequency activity coupled with emerging clinical features, including rigid immobility and semiologies such as automatisms, during the postictal period supports the presence of ongoing seizure-related neuronal activity in unrecorded brain regions.
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Affiliation(s)
- Lisa M Bateman
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Anil Mendiratta
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Jyun-You Liou
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, New York
| | - Elliot J Smith
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Carl W Bazil
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Hyunmi Choi
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Alison Pack
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Shraddha Srinivasan
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, New York, New York
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31
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Abstract
Electroencephalographic (EEG) investigations are crucial in the diagnosis and management of patients with focal epilepsies. EEG may reveal different interictal epileptiform discharges (IEDs: abnormal spikes, sharp waves). The EEG visibility of a spike depends on the surface area of cortex involved (>10cm2) and the brain localization of cortical generators. Regions generating IEDs (defining the "irritative zone") are not necessarily equivalent to the seizure onset zone. Focal seizures are dynamic processes originating from one or several brain regions (that generate fast oscillations and are called the epileptogenic zone) before spreading to other structures (that generate lower frequency oscillations and are called the propagation zone). Several factors limit the expression of seizures on scalp EEG, such as the area involved, degree of synchronization, and depth of the cortical generators. Different scalp EEG seizure onset patterns may be observed: fast discharge, background flattening, rhythmic spikes, sinusoidal discharge, or sharp activity. However, to a large extent EEG changes are linked to seizure propagation. Finally, in the context of presurgical evaluation, the combination of interictal and ictal EEG features is crucial to provide an optimal hypothesis concerning the epileptogenic zone.
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Affiliation(s)
- Stanislas Lagarde
- Institut de Neurosciences des Systèmes, Aix Marseille Université, Marseille, France; Department of Clinical Neurophysiology, Timone Hospital, Marseille, France
| | - Fabrice Bartolomei
- Institut de Neurosciences des Systèmes, Aix Marseille Université, Marseille, France; Department of Clinical Neurophysiology, Timone Hospital, Marseille, France.
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32
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Bumanglag AV, Sloviter RS. No latency to dentate granule cell epileptogenesis in experimental temporal lobe epilepsy with hippocampal sclerosis. Epilepsia 2018; 59:2019-2034. [PMID: 30338519 DOI: 10.1111/epi.14580] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/19/2018] [Accepted: 09/19/2018] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To determine when spontaneous granule cell epileptiform discharges first occur after hippocampal injury, and to identify the postinjury "latent" period as either a "silent" gestational state of epileptogenesis or a subtle epileptic state in gradual transition to a more obvious epileptic state. METHODS Nonconvulsive status epilepticus evoked by perforant path stimulation in urethane-sedated rats produced selective and extensive hippocampal injury and a "latent" period that preceded the onset of the first clinically obvious epileptic seizures. Continuous granule cell layer depth recording and video monitoring assessed the time course of granule cell hyperexcitability and the onset/offset times of spontaneous epileptiform discharges and behavioral seizures. RESULTS One day postinjury, granule cells in awake rats were hyperexcitable to afferent input, and continuously generated spontaneous population spikes. During the ~2-4 week "latent" period, granule cell epileptiform discharges lasting ~30 seconds caused subtle focal seizures characterized by immobilization and facial automatisms that were undetected by behavioral assessment alone but identified post hoc. Granule cell layer epileptiform discharge duration eventually tripled, which caused the first clinically obvious seizure, ending the "latent" period. Behavioral seizure duration was linked tightly to spontaneous granule cell layer events. Granule cell epileptiform discharges preceded all behavioral seizure onsets, and clonic behaviors ended abruptly within seconds of the termination of each granule cell epileptiform discharge. Noninjurious hippocampal excitation produced no evidence of granule cell hyperexcitability or epileptogenesis. SIGNIFICANCE The latent period in this model is a subtle epileptic state in transition to a more clinically obvious epileptic state, not a seizure-free "gestational" state when an unidentified epileptogenic mechanism gradually develops. Based on the onset/offset times of electrographic and behavioral events, granule cell behavior may be the prime determinant of seizure onset, phenotype, duration, and offset in this model of hippocampal-onset epilepsy. Extensive hippocampal neuron loss could be the primary epileptogenic mechanism.
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Affiliation(s)
| | - Robert S Sloviter
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, Georgia.,Department of Neurobiology, Morehouse School of Medicine, Atlanta, Georgia.,Department of Pharmacology & Toxicology, Morehouse School of Medicine, Atlanta, Georgia
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The Hippocampus and Cortex Together Generate the Scalp EEG Ictal Discharge in Temporal Lobe Epilepsy. J Clin Neurophysiol 2018; 34:448-455. [PMID: 28574952 DOI: 10.1097/wnp.0000000000000394] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The scalp EEG ictal discharge in temporal lobe epilepsy is reportedly visible only after the intracranial discharge becomes well synchronized and present over 10 to 30 cm of cortex. We investigated the role of the hippocampal formation in the generation of the scalp EEG ictal discharge. METHODS Intracranial EEG video monitors were recorded using simultaneous scalp, stereotaxic depth, and subdural strip electrodes in 19 subjects with temporal lobe epilepsy. The location, frequency, morphology, and timing of the initial ictal discharge, and subsequent ictal patterns, were examined in hippocampal formation, medial paleocortex, and lateral temporal neocortex electrocorticographic and scalp temporal EEG recordings. RESULTS In every subject, a scalp ictal discharge was visible only after the intracranial ictal discharge had spread to involve the whole temporal lobe (hippocampal formation, medial paleocortex, and lateral temporal neocortex). Beta/gamma frequency and decremental electrocorticographic ictal discharges were never visualized in the EEG. The scalp EEG ictal discharge frequency was 2.4 to 10 Hz and appeared a median of 18 seconds after a faster frequency electrocorticographic initial ictal discharge, once the intracranial discharge slowed to an alpha, theta, or delta frequency. CONCLUSIONS In temporal lobe epilepsy, an ictal pattern is not readily visible in the scalp EEG until the intracranial ictal discharge is ≤10 Hz and has propagated from its site of onset to involve the hippocampus, medial paleocortex, and lateral temporal neocortex.
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Sharma P, Scherg M, Pinborg LH, Fabricius M, Rubboli G, Pedersen B, Leffers AM, Uldall P, Jespersen B, Brennum J, Henriksen OM, Beniczky S. Ictal and interictal electric source imaging in pre-surgical evaluation: a prospective study. Eur J Neurol 2018; 25:1154-1160. [DOI: 10.1111/ene.13676] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 05/03/2018] [Indexed: 12/01/2022]
Affiliation(s)
- P. Sharma
- Department of Clinical Neurophysiology; Danish Epilepsy Centre; Dianalund Denmark
- Department of Neurology; King George's Medical University; Lucknow India
| | - M. Scherg
- Research Department; BESA GmbH; Gräfelfing Germany
| | - L. H. Pinborg
- Department of Neurology; Copenhagen University Hospital Rigshospitalet; Copenhagen
- Neurobiology Research Unit; Copenhagen University Hospital Rigshospitalet; Copenhagen
| | - M. Fabricius
- Department of Clinical Neurophysiology; Copenhagen University Hospital Rigshospitalet; Copenhagen
| | - G. Rubboli
- Department of Neurology; Danish Epilepsy Centre; Dianalund
| | - B. Pedersen
- Department of Neurology; Danish Epilepsy Centre; Dianalund
| | - A.-M. Leffers
- Department of Diagnostic Radiology; Hvidovre Hospital; Hvidovre
| | - P. Uldall
- Department of Paediatrics, Child Neurology; Copenhagen University Hospital Rigshospitalet; Copenhagen
| | - B. Jespersen
- Department of Neurosurgery; Copenhagen University Hospital Rigshospitalet; Copenhagen
| | - J. Brennum
- Department of Neurosurgery; Copenhagen University Hospital Rigshospitalet; Copenhagen
| | - O. M. Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET; Copenhagen University Hospital Rigshospitalet; Copenhagen
| | - S. Beniczky
- Department of Clinical Neurophysiology; Danish Epilepsy Centre; Dianalund Denmark
- Department of Clinical Neurophysiology; Aarhus University Hospital; Aarhus Denmark
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Abramovici S, Antony A, Baldwin ME, Urban A, Ghearing G, Pan J, Sun T, Krafty RT, Richardson RM, Bagic A. Features of Simultaneous Scalp and Intracranial EEG That Predict Localization of Ictal Onset Zone. Clin EEG Neurosci 2018; 49:206-212. [PMID: 29067832 DOI: 10.1177/1550059417738688] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To assess the utility of simultaneous scalp EEG in patients with focal epilepsy undergoing intracranial EEG evaluation after a detailed presurgical testing, including an inpatient scalp video EEG evaluation. METHODS Patients who underwent simultaneous scalp and intracranial EEG (SSIEEG) monitoring were classified into group 1 or 2 depending on whether the seizure onset zone was delineated or not. Seizures were analyzed using the following 3 EEG features at the onset of seizures latency, location, and pattern. RESULTS The criteria showed at least one of the following features when comparing SSIEEG: prolonged latency, absence of anatomical congruence, lack of concordance of EEG pattern in 11.11% (1/9) of the patients in group 1 and 75 % (3/4) of the patients in group 2. These 3 features were not present in any of the 5 patients who had Engel class I outcome compared with 1 of the 2 patients (50%) who had seizure recurrence after resective surgery. The mean latency of seizure onset in scalp EEG compared with intracranial EEG of patients in group 1 was 17.48 seconds (SD = 16.07) compared with 4.33 seconds (SD = 11.24) in group 2 ( P = .03). None of the seizures recorded in patients in group 1 had a discordant EEG pattern in SSIEEG. CONCLUSION Concordance in EEG features like latency, location, and EEG pattern, at the onset of seizures in SSIEEG is associated with a favorable outcome after epilepsy surgery in patients with intractable focal epilepsy. SIGNIFICANCE Simultaneous scalp EEG complements intracranial EEG evaluation even after a detailed inpatient scalp video EEG evaluation and could be part of standard intracranial EEG studies in patients with intractable focal epilepsy.
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Affiliation(s)
| | - Arun Antony
- 2 University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Maria Elizabeth Baldwin
- 2 University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Alexandra Urban
- 2 University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Gena Ghearing
- 2 University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Julie Pan
- 2 University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Tao Sun
- 3 Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert Todd Krafty
- 3 Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - R Mark Richardson
- 4 Department of Neurosurgery, University of Pittsburgh Medical Center, UPMC Presbyterian, Pittsburgh, PA, USA
| | - Anto Bagic
- 2 University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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Koren J, Gritsch G, Pirker S, Herta J, Perko H, Kluge T, Baumgartner C. Automatic ictal onset source localization in presurgical epilepsy evaluation. Clin Neurophysiol 2018; 129:1291-1299. [PMID: 29680731 DOI: 10.1016/j.clinph.2018.03.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 03/07/2018] [Accepted: 03/24/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVE To test the diagnostic accuracy of a new automatic algorithm for ictal onset source localization (IOSL) during routine presurgical epilepsy evaluation following STARD (Standards for Reporting of Diagnostic Accuracy) criteria. METHODS We included 28 consecutive patients with refractory focal epilepsy (25 patients with temporal lobe epilepsy (TLE) and 3 with extratemporal epilepsy) who underwent resective epilepsy surgery. Ictal EEG patterns were analyzed with a novel automatic IOSL algorithm. IOSL source localizations on a sublobar level were validated by comparison with actual resection sites and seizure free outcome 2 years after surgery. RESULTS Sensitivity of IOSL was 92.3% (TLE: 92.3%); specificity 60% (TLE: 50%); positive predictive value 66.7% (TLE: 66.7%); and negative predictive value 90% (TLE: 85.7%). The likelihood ratio was more than ten times higher for concordant IOSL results as compared to discordant results (p = 0.013). CONCLUSIONS We demonstrated the clinical feasibility of our IOSL approach yielding reasonable high performance measures on a sublobar level. SIGNIFICANCE Our IOSL method may contribute to a correct localization of the seizure onset zone in temporal lobe epilepsy and can readily be used in standard epilepsy monitoring settings. Further studies are needed for validation in extratemporal epilepsy.
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Affiliation(s)
- Johannes Koren
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Neurological Department, General Hospital Hietzing with Neurological Center Rosenhügel, Vienna, Austria
| | - Gerhard Gritsch
- Austrian Institute of Technology GmbH (AIT), Safety & Security Department, Vienna, Austria
| | - Susanne Pirker
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Neurological Department, General Hospital Hietzing with Neurological Center Rosenhügel, Vienna, Austria
| | - Johannes Herta
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Hannes Perko
- Austrian Institute of Technology GmbH (AIT), Safety & Security Department, Vienna, Austria
| | - Tilmann Kluge
- Austrian Institute of Technology GmbH (AIT), Safety & Security Department, Vienna, Austria
| | - Christoph Baumgartner
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Neurological Department, General Hospital Hietzing with Neurological Center Rosenhügel, Vienna, Austria; Department of Epileptology and Clinical Neurophysiology, Sigmund Freud University, Vienna, Austria.
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Tanaka H, Khoo HM, Dubeau F, Gotman J. Association between scalp and intracerebral electroencephalographic seizure-onset patterns: A study in different lesional pathological substrates. Epilepsia 2017; 59:420-430. [PMID: 29226305 DOI: 10.1111/epi.13979] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Our purpose was to determine the correlation between scalp electroencephalography (EEG) and intracerebral EEG (iEEG) seizure-onset patterns in patients with focal lesional epilepsy to determine whether scalp seizure-onset patterns can be specific to intracerebral seizure-onset patterns and to lesion type. METHODS We retrospectively analyzed 61 patients with focal epilepsy and a structural magnetic resonance imaging (MRI)-visible lesion, who first underwent extensive scalp recordings and then iEEG studies (stereo-EEG) for presurgical evaluation, and who showed an iEEG seizure onset in the lesional/perilesional area. Five seizure-onset patterns were recognized on scalp EEG, and 7 on iEEG, and in each patient, only the predominant scalp and iEEG seizure-onset patterns were compared. Because scalp and iEEG recordings were acquired at different times, we followed strict criteria based on semiology and topography to match scalp with intracerebral seizures. RESULTS Seventy-one pairs of seizure-onset patterns matched between scalp and iEEG were identified. Each scalp pattern did not correspond to a single intracerebral pattern, but there were significant associations: (1) paroxysmal fast activity (≥13 Hz) at scalp onset was associated with low-voltage fast activity at iEEG onset (P < .001), with malformations of cortical development (P < .001), and with superficial seizure-onset zone based on iEEG (P < .001); (2) rhythmic slow activity (<13 Hz) at scalp onset was associated with low-frequency high-amplitude periodic spikes at iEEG onset (P = .0014), with medial temporal atrophy/sclerosis (P < .001), and with deep seizure-onset zone (P < .001); and (3) repetitive epileptiform discharge at scalp onset was associated with a burst of high-amplitude polyspikes at iEEG onset (P = .0002). SIGNIFICANCE Our results disclosed that in focal epilepsy patients with seizures generated in an MRI-visible lesion, some scalp seizure-onset patterns are highly associated with a specific intracerebral pattern, with specific pathologies, and with the depth of seizure-onset zone. These findings allow the interpretation of scalp seizure-onset patterns to be significantly more informative.
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Affiliation(s)
- Hideaki Tanaka
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurosurgery, Fukuoka University Hospital, Fukuoka City, Japan
| | - Hui Ming Khoo
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Japan
| | - François Dubeau
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Jean Gotman
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
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Lam AD, Maus D, Zafar SF, Cole AJ, Cash SS. SCOPE-mTL: A non-invasive tool for identifying and lateralizing mesial temporal lobe seizures prior to scalp EEG ictal onset. Clin Neurophysiol 2017; 128:1647-1655. [PMID: 28732342 DOI: 10.1016/j.clinph.2017.06.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/01/2017] [Accepted: 06/14/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE In mesial temporal lobe (mTL) epilepsy, seizure onset can precede the appearance of a scalp EEG ictal pattern by many seconds. The ability to identify this early, occult mTL seizure activity could improve lateralization and localization of mTL seizures on scalp EEG. METHODS Using scalp EEG spectral features and machine learning approaches on a dataset of combined scalp EEG and foramen ovale electrode recordings in patients with mTL epilepsy, we developed an algorithm, SCOPE-mTL, to detect and lateralize early, occult mTL seizure activity, prior to the appearance of a scalp EEG ictal pattern. RESULTS Using SCOPE-mTL, 73% of seizures with occult mTL onset were identified as such, and no seizures that lacked an occult mTL onset were identified as having one. Predicted mTL seizure onset times were highly correlated with actual mTL seizure onset times (r=0.69). 50% of seizures with early mTL onset were lateralizable prior to scalp ictal onset, with 94% accuracy. CONCLUSIONS SCOPE-mTL can identify and lateralize mTL seizures prior to scalp EEG ictal onset, with high sensitivity, specificity, and accuracy. SIGNIFICANCE Quantitative analysis of scalp EEG can provide important information about mTL seizures, even in the absence of a visible scalp EEG ictal correlate.
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Affiliation(s)
- Alice D Lam
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Douglas Maus
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sahar F Zafar
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew J Cole
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sydney S Cash
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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van Mierlo P, Strobbe G, Keereman V, Birot G, Gadeyne S, Gschwind M, Carrette E, Meurs A, Van Roost D, Vonck K, Seeck M, Vulliémoz S, Boon P. Automated long-term EEG analysis to localize the epileptogenic zone. Epilepsia Open 2017; 2:322-333. [PMID: 29588961 PMCID: PMC5862106 DOI: 10.1002/epi4.12066] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2017] [Indexed: 11/10/2022] Open
Abstract
Objective We investigated the performance of automatic spike detection and subsequent electroencephalogram (EEG) source imaging to localize the epileptogenic zone (EZ) from long-term EEG recorded during video-EEG monitoring. Methods In 32 patients, spikes were automatically detected in the EEG and clustered according to their morphology. The two spike clusters with most single events in each patient were averaged and localized in the brain at the half-rising time and peak of the spike using EEG source imaging. On the basis of the distance from the sources to the resection and the known patient outcome after surgery, the performance of the automated EEG analysis to localize the EZ was quantified. Results In 28 out of the 32 patients, the automatically detected spike clusters corresponded with the reported interictal findings. The median distance to the resection in patients with Engel class I outcome was 6.5 and 15 mm for spike cluster 1 and 27 and 26 mm for cluster 2, at the peak and the half-rising time of the spike, respectively. Spike occurrence (cluster 1 vs. cluster 2) and spike timing (peak vs. half-rising) significantly influenced the distance to the resection (p < 0.05). For patients with Engel class II, III, and IV outcomes, the median distance increased to 36 and 36 mm for cluster 1. Localizing spike cluster 1 at the peak resulted in a sensitivity of 70% and specificity of 100%, positive prediction value (PPV) of 100%, and negative predictive value (NPV) of 53%. Including the results of spike cluster 2 led to an increased sensitivity of 79% NPV of 55% and diagnostic OR of 11.4, while the specificity dropped to 75% and the PPV to 90%. Significance We showed that automated analysis of long-term EEG recordings results in a high sensitivity and specificity to localize the epileptogenic focus.
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Affiliation(s)
- Pieter van Mierlo
- Medical Image and Signal Processing Group Department of Electronics and Information Systems Ghent University-iMinds Medical IT Department Ghent Belgium.,Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland
| | - Gregor Strobbe
- Medical Image and Signal Processing Group Department of Electronics and Information Systems Ghent University-iMinds Medical IT Department Ghent Belgium
| | - Vincent Keereman
- Medical Image and Signal Processing Group Department of Electronics and Information Systems Ghent University-iMinds Medical IT Department Ghent Belgium.,Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Gwénael Birot
- Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland
| | - Stefanie Gadeyne
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Markus Gschwind
- Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland.,Epilepsy and EEG Unit University Hospital of Geneva Geneva Switzerland
| | - Evelien Carrette
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Alfred Meurs
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Dirk Van Roost
- Department of Neurosurgery Ghent University Hospital Ghent Belgium
| | - Kristl Vonck
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Margitta Seeck
- Epilepsy and EEG Unit University Hospital of Geneva Geneva Switzerland
| | - Serge Vulliémoz
- Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland.,Epilepsy and EEG Unit University Hospital of Geneva Geneva Switzerland
| | - Paul Boon
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
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Temporal lobe spikes: EEG-fMRI contributions to the "mesial vs. lateral" debate. Clin Neurophysiol 2017; 128:986-991. [PMID: 28445839 DOI: 10.1016/j.clinph.2017.03.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 02/13/2017] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE It has been reported that interictal epileptic discharges (IEDs) recorded in temporal regions on scalp EEG are unlikely to originate from mesial temporal structures. However, EEG-fMRI sometimes show mesial temporal activation. We hypothesized that BOLD activation in the temporal neocortex is weaker than in the mesial structures, reflecting the fact that propagated activity has less metabolic demand than the original discharge. METHODS Twelve patients with epilepsy who have BOLD response in mesial temporal structures were selected from our EEG-fMRI database. We searched the temporal lobe ipsilateral to IEDs and checked whether there is positive BOLD response in the neocortex. RESULTS All IED types showed a BOLD response in the temporal neocortex ipsilateral to the mesial temporal BOLD response. T-values were higher in mesial temporal structures than in neocortex in 13/16 cases. CONCLUSIONS Hemodynamic changes were observed in the mesial temporal lobe at the time of IEDs recorded from the temporal region on the scalp. The finding of smaller BOLD changes in the ipsilateral neocortex is in agreement with our hypothesis. SIGNIFICANCE Our study indicates that scalp-recorded temporal lobe spikes are likely to result from mesial temporal spikes propagating neuronally to the neocortex.
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41
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Vossel KA, Ranasinghe KG, Beagle AJ, Mizuiri D, Honma SM, Dowling AF, Darwish SM, Van Berlo V, Barnes DE, Mantle M, Karydas AM, Coppola G, Roberson ED, Miller BL, Garcia PA, Kirsch HE, Mucke L, Nagarajan SS. Incidence and impact of subclinical epileptiform activity in Alzheimer's disease. Ann Neurol 2016; 80:858-870. [PMID: 27696483 DOI: 10.1002/ana.24794] [Citation(s) in RCA: 333] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Seizures are more frequent in patients with Alzheimer's disease (AD) and can hasten cognitive decline. However, the incidence of subclinical epileptiform activity in AD and its consequences are unknown. Motivated by results from animal studies, we hypothesized higher than expected rates of subclinical epileptiform activity in AD with deleterious effects on cognition. METHODS We prospectively enrolled 33 patients (mean age, 62 years) who met criteria for AD, but had no history of seizures, and 19 age-matched, cognitively normal controls. Subclinical epileptiform activity was assessed, blinded to diagnosis, by overnight long-term video-electroencephalography (EEG) and a 1-hour resting magnetoencephalography exam with simultaneous EEG. Patients also had comprehensive clinical and cognitive evaluations, assessed longitudinally over an average period of 3.3 years. RESULTS Subclinical epileptiform activity was detected in 42.4% of AD patients and 10.5% of controls (p = 0.02). At the time of monitoring, AD patients with epileptiform activity did not differ clinically from those without such activity. However, patients with subclinical epileptiform activity showed faster declines in global cognition, determined by the Mini-Mental State Examination (3.9 points/year in patients with epileptiform activity vs 1.6 points/year in patients without; p = 0.006), and in executive function (p = 0.01). INTERPRETATION Extended monitoring detects subclinical epileptiform activity in a substantial proportion of patients with AD. Patients with this indicator of network hyperexcitability are at risk for accelerated cognitive decline and might benefit from antiepileptic therapies. These data call for more sensitive and comprehensive neurophysiological assessments in AD patient evaluations and impending clinical trials. Ann Neurol 2016;80:858-870.
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Affiliation(s)
- Keith A Vossel
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
- Gladstone Institute of Neurological Disease, San Francisco, CA
| | - Kamalini G Ranasinghe
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Alexander J Beagle
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Danielle Mizuiri
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Susanne M Honma
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Anne F Dowling
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Sonja M Darwish
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Victoria Van Berlo
- Department of Neurology and Semel Institute for Neuroscience and Human Behavior in the Department of Psychiatry, University of California Los Angeles, Los Angeles, CA
| | - Deborah E Barnes
- Departments of Psychiatry and Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA
- Veterans Affairs Medical Center, San Francisco, CA
| | - Mary Mantle
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Anna M Karydas
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Giovanni Coppola
- Department of Neurology and Semel Institute for Neuroscience and Human Behavior in the Department of Psychiatry, University of California Los Angeles, Los Angeles, CA
| | - Erik D Roberson
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL
| | - Bruce L Miller
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Paul A Garcia
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Heidi E Kirsch
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Lennart Mucke
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
- Gladstone Institute of Neurological Disease, San Francisco, CA
| | - Srikantan S Nagarajan
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
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Beniczky S, Rosenzweig I, Scherg M, Jordanov T, Lanfer B, Lantz G, Larsson PG. Ictal EEG source imaging in presurgical evaluation: High agreement between analysis methods. Seizure 2016; 43:1-5. [PMID: 27764709 PMCID: PMC5176190 DOI: 10.1016/j.seizure.2016.09.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 09/24/2016] [Accepted: 09/30/2016] [Indexed: 11/17/2022] Open
Abstract
There was good agreement between different methods of ictal EEG source imaging. Ictal source imaging achieved an accuracy of 73% (for operated patients: 86%). Agreement between all methods did not necessarily imply accuracy of localization.
Purpose To determine the agreement between five different methods of ictal EEG source imaging, and to assess their accuracy in presurgical evaluation of patients with focal epilepsy. It was hypothesized that high agreement between methods was associated with higher localization-accuracy. Methods EEGs were recorded with a 64-electrode array. Thirty-eight seizures from 22 patients were analyzed using five different methods phase mapping, dipole fitting, CLARA, cortical-CLARA and minimum norm. Localization accuracy was determined at sub-lobar level. Reference standard was the final decision of the multidisciplinary epilepsy surgery team, and, for the operated patients, outcome one year after surgery. Results Agreement between all methods was obtained in 13 patients (59%) and between all but one methods in additional six patients (27%). There was a trend for minimum norm being less accurate than phase mapping, but none of the comparisons reached significance. Source imaging in cases with agreement between all methods was not more accurate than in the other cases. Ictal source imaging achieved an accuracy of 73% (for operated patients: 86%). Conclusion There was good agreement between different methods of ictal source imaging. However, good inter-method agreement did not necessarily imply accurate source localization, since all methods faced the limitations of the inverse solution.
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Affiliation(s)
- Sándor Beniczky
- Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
| | - Ivana Rosenzweig
- Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; Sleep and Brain Plasticity Centre, Department of Neuroimaging, IOPPN, King's College and Imperial College, London, UK
| | | | | | | | - Göran Lantz
- Clinical Neurophysiology Unit, Department of Clinical Sciences, Lund University, Lund, Sweden; Electrical Geodesics, Inc., Eugene, OR, USA
| | - Pål Gunnar Larsson
- Clinical Neurophysiology Section, Department of Neurosurgery, Oslo University Hospital, Norway
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Lam AD, Zepeda R, Cole AJ, Cash SS. Widespread changes in network activity allow non-invasive detection of mesial temporal lobe seizures. Brain 2016; 139:2679-2693. [PMID: 27474219 DOI: 10.1093/brain/aww198] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 06/20/2016] [Indexed: 11/14/2022] Open
Abstract
Decades of experience with intracranial recordings in patients with epilepsy have demonstrated that seizures can occur in deep cortical regions such as the mesial temporal lobes without showing any obvious signs of seizure activity on scalp electroencephalogram. Predicated on the idea that these seizures are purely focal, currently, the only way to detect these 'scalp-negative seizures' is with intracranial recordings. However, intracranial recordings are only rarely performed in patients with epilepsy, and are almost never performed outside of the context of epilepsy. As such, little is known about scalp-negative seizures and their role in the natural history of epilepsy, their effect on cognitive function, and their association with other neurological diseases. Here, we developed a novel approach to non-invasively identify scalp-negative seizures arising from the mesial temporal lobe based on scalp electroencephalogram network connectivity measures. We identified 25 scalp-negative mesial temporal lobe seizures in 10 patients and obtained control records from an additional 13 patients, all of whom underwent recordings with foramen ovale electrodes and scalp electroencephalogram. Scalp data from these records were used to train a scalp-negative seizure detector, which consisted of a pair of logistic regression classifiers that used scalp electroencephalogram coherence properties as input features. On cross-validation performance, this detector correctly identified scalp-negative seizures in 40% of patients, and correctly identified the side of seizure onset for each seizure detected. In comparison, routine clinical interpretation of these scalp electroencephalograms failed to identify any of the scalp-negative seizures. Among the patients in whom the detector raised seizure alarms, 80% had scalp-negative mesial temporal lobe seizures. The detector had a false alarm rate of only 0.31 per day and a positive predictive value of 75%. Of the 13 control patients, false seizure alarms were raised in only one patient. The fact that our detector specifically recognizes focal mesial temporal lobe seizures based on scalp electroencephalogram coherence features, lends weight to the hypothesis that even focal seizures are a network phenomenon that involve widespread neural connectivity. Our scalp-negative seizure detector has clear clinical utility in patients with temporal lobe epilepsy, and its potential easily translates to other neurological disorders, such as Alzheimer's disease, in which occult mesial temporal lobe seizures are suspected to play a significant role. Importantly, our work establishes a novel approach of using computational approaches to non-invasively detect deep seizure activity, without the need for invasive intracranial recordings.
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Affiliation(s)
- Alice D Lam
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Rodrigo Zepeda
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Andrew J Cole
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
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Avoli M, de Curtis M, Gnatkovsky V, Gotman J, Köhling R, Lévesque M, Manseau F, Shiri Z, Williams S. Specific imbalance of excitatory/inhibitory signaling establishes seizure onset pattern in temporal lobe epilepsy. J Neurophysiol 2016; 115:3229-37. [PMID: 27075542 DOI: 10.1152/jn.01128.2015] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/06/2016] [Indexed: 11/22/2022] Open
Abstract
Low-voltage fast (LVF) and hypersynchronous (HYP) patterns are the seizure-onset patterns most frequently observed in intracranial EEG recordings from mesial temporal lobe epilepsy (MTLE) patients. Both patterns also occur in models of MTLE in vivo and in vitro, and these studies have highlighted the predominant involvement of distinct neuronal network/neurotransmitter receptor signaling in each of them. First, LVF-onset seizures in epileptic rodents can originate from several limbic structures, frequently spread, and are associated with high-frequency oscillations in the ripple band (80-200 Hz), whereas HYP onset seizures initiate in the hippocampus and tend to remain focal with predominant fast ripples (250-500 Hz). Second, in vitro intracellular recordings from principal cells in limbic areas indicate that pharmacologically induced seizure-like discharges with LVF onset are initiated by a synchronous inhibitory event or by a hyperpolarizing inhibitory postsynaptic potential barrage; in contrast, HYP onset is associated with a progressive impairment of inhibition and concomitant unrestrained enhancement of excitation. Finally, in vitro optogenetic experiments show that, under comparable experimental conditions (i.e., 4-aminopyridine application), the initiation of LVF- or HYP-onset seizures depends on the preponderant involvement of interneuronal or principal cell networks, respectively. Overall, these data may provide insight to delineate better therapeutic targets in the treatment of patients presenting with MTLE and, perhaps, with other epileptic disorders as well.
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Affiliation(s)
- Massimo Avoli
- Montreal Neurological Institute and Departments of Neurology & Neurosurgery and of Physiology, McGill University, Montréal, Québec, Canada; Facoltà di Medicina e Odontoiatria, Sapienza Università di Roma, Rome, Italy;
| | - Marco de Curtis
- Epilepsy Unit, Fondazione Istituto Neurologico Carlo Besta, Milan, Italy
| | - Vadym Gnatkovsky
- Epilepsy Unit, Fondazione Istituto Neurologico Carlo Besta, Milan, Italy
| | - Jean Gotman
- Montreal Neurological Institute and Departments of Neurology & Neurosurgery and of Physiology, McGill University, Montréal, Québec, Canada
| | - Rüdiger Köhling
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany; and
| | - Maxime Lévesque
- Montreal Neurological Institute and Departments of Neurology & Neurosurgery and of Physiology, McGill University, Montréal, Québec, Canada
| | - Frédéric Manseau
- Douglas Mental Health University Institute, McGill University, Montréal, Québec, Canada
| | - Zahra Shiri
- Montreal Neurological Institute and Departments of Neurology & Neurosurgery and of Physiology, McGill University, Montréal, Québec, Canada
| | - Sylvain Williams
- Douglas Mental Health University Institute, McGill University, Montréal, Québec, Canada
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Shiri Z, Manseau F, Lévesque M, Williams S, Avoli M. Activation of specific neuronal networks leads to different seizure onset types. Ann Neurol 2016; 79:354-65. [PMID: 26605509 DOI: 10.1002/ana.24570] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/12/2015] [Accepted: 11/15/2015] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Ictal events occurring in temporal lobe epilepsy patients and in experimental models mimicking this neurological disorder can be classified, based on their onset pattern, into low-voltage, fast versus hypersynchronous onset seizures. It has been suggested that the low-voltage, fast onset pattern is mainly contributed by interneuronal (γ-aminobutyric acidergic) signaling, whereas the hypersynchronous onset involves the activation of principal (glutamatergic) cells. METHODS Here, we tested this hypothesis using the optogenetic control of parvalbumin-positive or somatostatin-positive interneurons and of calmodulin-dependent, protein kinase-positive, principal cells in the mouse entorhinal cortex in the in vitro 4-aminopyridine model of epileptiform synchronization. RESULTS We found that during 4-aminopyridine application, both spontaneous seizure-like events and those induced by optogenetic activation of interneurons displayed low-voltage, fast onset patterns that were associated with a higher occurrence of ripples than of fast ripples. In contrast, seizures induced by the optogenetic activation of principal cells had a hypersynchronous onset pattern with fast ripple rates that were higher than those of ripples. INTERPRETATION Our results firmly establish that under a similar experimental condition (ie, bath application of 4-aminopyridine), the initiation of low-voltage, fast and of hypersynchronous onset seizures in the entorhinal cortex depends on the preponderant involvement of interneuronal and principal cell networks, respectively.
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Affiliation(s)
- Zahra Shiri
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, and Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Frédéric Manseau
- Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada
| | - Maxime Lévesque
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, and Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Sylvain Williams
- Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada
| | - Massimo Avoli
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, and Department of Physiology, McGill University, Montreal, Quebec, Canada
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Strobbe G, Carrette E, López JD, Montes Restrepo V, Van Roost D, Meurs A, Vonck K, Boon P, Vandenberghe S, van Mierlo P. Electrical source imaging of interictal spikes using multiple sparse volumetric priors for presurgical epileptogenic focus localization. NEUROIMAGE-CLINICAL 2016; 11:252-263. [PMID: 26958464 PMCID: PMC4773507 DOI: 10.1016/j.nicl.2016.01.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/09/2015] [Accepted: 01/17/2016] [Indexed: 11/07/2022]
Abstract
Electrical source imaging of interictal spikes observed in EEG recordings of patients with refractory epilepsy provides useful information to localize the epileptogenic focus during the presurgical evaluation. However, the selection of the time points or time epochs of the spikes in order to estimate the origin of the activity remains a challenge. In this study, we consider a Bayesian EEG source imaging technique for distributed sources, i.e. the multiple volumetric sparse priors (MSVP) approach. The approach allows to estimate the time courses of the intensity of the sources corresponding with a specific time epoch of the spike. Based on presurgical averaged interictal spikes in six patients who were successfully treated with surgery, we estimated the time courses of the source intensities for three different time epochs: (i) an epoch starting 50 ms before the spike peak and ending at 50% of the spike peak during the rising phase of the spike, (ii) an epoch starting 50 ms before the spike peak and ending at the spike peak and (iii) an epoch containing the full spike time period starting 50 ms before the spike peak and ending 230 ms after the spike peak. To identify the primary source of the spike activity, the source with the maximum energy from 50 ms before the spike peak till 50% of the spike peak was subsequently selected for each of the time windows. For comparison, the activity at the spike peaks and at 50% of the peaks was localized using the LORETA inversion technique and an ECD approach. Both patient-specific spherical forward models and patient-specific 5-layered finite difference models were considered to evaluate the influence of the forward model. Based on the resected zones in each of the patients, extracted from post-operative MR images, we compared the distances to the resection border of the estimated activity. Using the spherical models, the distances to the resection border for the MSVP approach and each of the different time epochs were in the same range as the LORETA and ECD techniques. We found distances smaller than 23 mm, with robust results for all the patients. For the finite difference models, we found that the distances to the resection border for the MSVP inversions of the full spike time epochs were generally smaller compared to the MSVP inversions of the time epochs before the spike peak. The results also suggest that the inversions using the finite difference models resulted in slightly smaller distances to the resection border compared to the spherical models. The results we obtained are promising because the MSVP approach allows to study the network of the estimated source-intensities and allows to characterize the spatial extent of the underlying sources. A Bayesian ESI technique is evaluated to localize interictal spike activity. Averaged spikes in six patients were used that were seizure free after surgery. We compared the technique with the LORETA an ECD technique. We evaluated both spherical and 5-layered finite difference forward models. Our approach is potentially useful to delineate the irritative zone.
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Affiliation(s)
- Gregor Strobbe
- Ghent University, Department of Electronics and Information Systems, MEDISIP, De Pintelaan 185, Building BB Floor 5, 9000 Ghent, Belgium; iMinds Medical IT Department, Belgium.
| | - Evelien Carrette
- Laboratory for Clinical and Experimental Neurophysiology, Ghent University Hospital, Ghent, Belgium.
| | - José David López
- SISTEMIC, Department of Electronic Engineering, Universidad de Antioquia UDEA, Calle 70 No. 52-21,Medellín, Colombia.
| | - Victoria Montes Restrepo
- Ghent University, Department of Electronics and Information Systems, MEDISIP, De Pintelaan 185, Building BB Floor 5, 9000 Ghent, Belgium; iMinds Medical IT Department, Belgium
| | - Dirk Van Roost
- Department of Neurosurgery, Ghent University Hospital, Ghent, Belgium.
| | - Alfred Meurs
- Laboratory for Clinical and Experimental Neurophysiology, Ghent University Hospital, Ghent, Belgium.
| | - Kristl Vonck
- Laboratory for Clinical and Experimental Neurophysiology, Ghent University Hospital, Ghent, Belgium.
| | - Paul Boon
- Laboratory for Clinical and Experimental Neurophysiology, Ghent University Hospital, Ghent, Belgium.
| | - Stefaan Vandenberghe
- Ghent University, Department of Electronics and Information Systems, MEDISIP, De Pintelaan 185, Building BB Floor 5, 9000 Ghent, Belgium; iMinds Medical IT Department, Belgium.
| | - Pieter van Mierlo
- Ghent University, Department of Electronics and Information Systems, MEDISIP, De Pintelaan 185, Building BB Floor 5, 9000 Ghent, Belgium; iMinds Medical IT Department, Belgium.
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Malter MP, Bahrenberg C, Niehusmann P, Elger CE, Surges R. Features of scalp EEG in unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis: Determining factors and predictive value for epilepsy surgery. Clin Neurophysiol 2015; 127:1081-1087. [PMID: 26321666 DOI: 10.1016/j.clinph.2015.06.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 05/12/2015] [Accepted: 06/21/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To investigate determining factors of the ictal scalp EEG pattern at seizure onset and its predictive value for postsurgical outcome in people with unilateral MTLE due to hippocampal sclerosis (MTLE-HS). METHODS Review of consecutive people with chronic MTLE-HS undergoing presurgical video-EEG telemetry. Exclusion criteria were additional epileptogenic lesions or seizure generators or compromised EEG traces at seizure-onset. Mixed linear or logistic regression models were used. RESULTS Inclusion of 63 patients with 219 seizures with a favorable outcome (no seizures or auras only) in 43 patients at last follow-up. Rhythmic activity at seizure-onset (RA) had a frequency of 4.7±1.5/s (range 1-8/s), mostly localized in the anterior temporal region. Postsurgical seizure outcome was not associated with any clinical or electrophysiological feature. RA in the delta-band was more often observed with shorter epilepsy duration (p=0.002). CONCLUSIONS RA on scalp EEG gets faster with increasing epilepsy duration, possibly via time-dependent alterations of epileptogenic networks. Neither the frequency of RA nor other EEG-features appeared to predict postsurgical seizure outcome. SIGNIFICANCE The results challenge the view that if patients with apparent MTLE display RA in the delta-band, seizure-onset in neocortical structures rather than in temporo-mesial tissue should be considered and further investigations should be prompted.
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Affiliation(s)
- Michael P Malter
- Department of Epileptology, University Hospital of Bonn, Germany; Department of Neurology, University Hospital Cologne, Germany
| | | | - Pitt Niehusmann
- Department of Neuropathology, University Hospital of Bonn, Germany
| | | | - Rainer Surges
- Department of Epileptology, University Hospital of Bonn, Germany.
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48
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de Curtis M, Avoli M. Initiation, Propagation, and Termination of Partial (Focal) Seizures. Cold Spring Harb Perspect Med 2015; 5:a022368. [PMID: 26134843 PMCID: PMC4484951 DOI: 10.1101/cshperspect.a022368] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The neurophysiological patterns that correlate with partial (focal) seizures are well defined in humans by standard electroencephalogram (EEG) and presurgical depth electrode recordings. Seizure patterns with similar features are reproduced in animal models of partial seizures and epilepsy. However, the network determinants that support interictal spikes, as well as the initiation, progression, and termination of seizures, are still elusive. Recent findings show that inhibitory networks are prominently involved at the onset of these seizures, and that extracellular changes in potassium contribute to initiate and sustain seizure progression. The end of a partial seizure correlates with an increase in network synchronization, which possibly involves both excitatory and inhibitory mechanisms.
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Affiliation(s)
- Marco de Curtis
- Unit of Epileptology and Experimental Neurophysiology and Fondazione Istituto Neurologico Carlo Besta, 20133 Milano, Italy
| | - Massimo Avoli
- Montreal Neurological Institute and Departments of Neurology and Neurosurgery and Physiology, McGill University, Montréal, H3A 2B4 Québec, Canada Department of Experimental Medicine, Facoltà di Medicina e Odontoiatria, Sapienza Università di Roma, 00185 Roma, Italy
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49
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Sachdev RNS, Gaspard N, Gerrard JL, Hirsch LJ, Spencer DD, Zaveri HP. Delta rhythm in wakefulness: evidence from intracranial recordings in human beings. J Neurophysiol 2015; 114:1248-54. [PMID: 26084904 DOI: 10.1152/jn.00249.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/15/2015] [Indexed: 11/22/2022] Open
Abstract
A widely accepted view is that wakefulness is a state in which the entire cortical mantle is persistently activated, and therefore desynchronized. Consequently, the EEG is dominated by low-amplitude, high-frequency fluctuations. This view is currently under revision because the 1-4 Hz delta rhythm is often evident during "quiet" wakefulness in rodents and nonhuman primates. Here we used intracranial EEG recordings to assess the occurrence of delta rhythm in 18 awake human beings. Our recordings reveal rhythmic delta during wakefulness at 10% of all recording sites. Delta rhythm could be observed in a single cortical lobe or in multiple lobes. Sites with high delta could flip between high and low delta power or could be in a persistently high delta state. Finally, these sites were rarely identified as the sites of seizure onset. Thus rhythmic delta can dominate the background operation and activity of some neocortical circuits in awake human beings.
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Affiliation(s)
- Robert N S Sachdev
- Institute for Biology, Humboldt University of Berlin, Neuroscience Research Center, Berlin, Germany;
| | - Nicolas Gaspard
- Department of Neurology, Hôpital Erasme-ULB, Cliniques universitaires de Bruxelles, Brussels, Belgium
| | - Jason L Gerrard
- Department of Neurosurgery, Yale University, New Haven, Connecticut; Department of Neurobiology, Yale University, New Haven, Connecticut; and
| | | | - Dennis D Spencer
- Department of Neurosurgery, Yale University, New Haven, Connecticut
| | - Hitten P Zaveri
- Department of Neurology, Yale University, New Haven, Connecticut
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50
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Tarnutzer AA, Lee SH, Robinson KA, Kaplan PW, Newman-Toker DE. Clinical and electrographic findings in epileptic vertigo and dizziness: a systematic review. Neurology 2015; 84:1595-604. [PMID: 25795644 DOI: 10.1212/wnl.0000000000001474] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 12/22/2014] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Seizures can cause vestibular symptoms, even without obvious epileptic features. We sought to characterize epileptic vertigo or dizziness (EVD) to improve differentiation from nonepileptic causes, particularly when vestibular symptoms are the sole manifestation. METHODS We conducted a systematic review with electronic (Medline) and manual search for English-language studies (1955-2014). Two independent reviewers selected studies. Study/patient characteristics were abstracted. We defined 3 study population types: (1) seizures, some experiencing vertigo/dizziness (disease cohort); (2) vertigo/dizziness, some due to seizures (symptom cohort); (3) vertigo/dizziness due to seizures in all patients (EVD-only cohort). RESULTS We identified 84 studies describing 11,354 patients (disease cohort = 8,129; symptom cohort = 2,965; EVD-only cohort = 260). Among 1,055 EVD patients in whom a distinction could be made, non-isolated EVD was present in 8.5%, isolated EVD in 0.8%. Thorough diagnostic workups (ictal EEG, vestibular testing, and brain MRI to exclude other causes) were rare (<0.1%). Ictal EEG was reported in 487 (4.3%), formal neuro-otologic assessment in 1,107 (9.7%). Localized EEG abnormalities (n = 350) were most frequently temporal (79.8%) and uncommonly parietal (11.8%). Duration of episodic vestibular symptoms varied, but was very brief (<30 seconds) in 69.6% of isolated EVD and 6.9% of non-isolated EVD. CONCLUSIONS Non-isolated EVD is much more prevalent than isolated EVD, which appears to be rare. Diagnostic evaluations for EVD are often incomplete. EVD is primarily associated with temporal lobe seizures; whether this reflects greater epidemiologic prevalence of temporal lobe seizures or a tighter association with dizziness/vertigo presentations than with other brain regions remains unknown. Consistent with clinical wisdom, isolated EVD spells often last just seconds, although many patients experience longer spells.
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Affiliation(s)
- Alexander A Tarnutzer
- From the Department of Neurology (A.A.T.), University Hospital Zurich and the University of Zurich, Switzerland; the Department of Neurology (S.-H.L.), Chonnam National University Medical School, Gwangju, South Korea; the Departments of Medicine (K.A.R.), Neurology (D.E.N.-T.), and Otolaryngology Head & Neck Surgery (D.E.N.-T.), The Johns Hopkins University School of Medicine; and the Department of Neurology (P.W.K.), Johns Hopkins Bayview Medical Center, Baltimore, MD.
| | - Seung-Han Lee
- From the Department of Neurology (A.A.T.), University Hospital Zurich and the University of Zurich, Switzerland; the Department of Neurology (S.-H.L.), Chonnam National University Medical School, Gwangju, South Korea; the Departments of Medicine (K.A.R.), Neurology (D.E.N.-T.), and Otolaryngology Head & Neck Surgery (D.E.N.-T.), The Johns Hopkins University School of Medicine; and the Department of Neurology (P.W.K.), Johns Hopkins Bayview Medical Center, Baltimore, MD
| | - Karen A Robinson
- From the Department of Neurology (A.A.T.), University Hospital Zurich and the University of Zurich, Switzerland; the Department of Neurology (S.-H.L.), Chonnam National University Medical School, Gwangju, South Korea; the Departments of Medicine (K.A.R.), Neurology (D.E.N.-T.), and Otolaryngology Head & Neck Surgery (D.E.N.-T.), The Johns Hopkins University School of Medicine; and the Department of Neurology (P.W.K.), Johns Hopkins Bayview Medical Center, Baltimore, MD
| | - Peter W Kaplan
- From the Department of Neurology (A.A.T.), University Hospital Zurich and the University of Zurich, Switzerland; the Department of Neurology (S.-H.L.), Chonnam National University Medical School, Gwangju, South Korea; the Departments of Medicine (K.A.R.), Neurology (D.E.N.-T.), and Otolaryngology Head & Neck Surgery (D.E.N.-T.), The Johns Hopkins University School of Medicine; and the Department of Neurology (P.W.K.), Johns Hopkins Bayview Medical Center, Baltimore, MD
| | - David E Newman-Toker
- From the Department of Neurology (A.A.T.), University Hospital Zurich and the University of Zurich, Switzerland; the Department of Neurology (S.-H.L.), Chonnam National University Medical School, Gwangju, South Korea; the Departments of Medicine (K.A.R.), Neurology (D.E.N.-T.), and Otolaryngology Head & Neck Surgery (D.E.N.-T.), The Johns Hopkins University School of Medicine; and the Department of Neurology (P.W.K.), Johns Hopkins Bayview Medical Center, Baltimore, MD
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