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Tojima M, Shimotake A, Neshige S, Okada T, Kobayashi K, Usami K, Matsuhashi M, Honda M, Takeyama H, Hitomi T, Yoshida T, Yokoyama A, Fushimi Y, Ueno T, Yamao Y, Kikuchi T, Namiki T, Arakawa Y, Takahashi R, Ikeda A. Specific consistency score for rational selection of epilepsy resection surgery candidates. Epilepsia 2024; 65:1322-1332. [PMID: 38470337 DOI: 10.1111/epi.17945] [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: 12/08/2023] [Revised: 02/24/2024] [Accepted: 02/26/2024] [Indexed: 03/13/2024]
Abstract
OBJECTIVE Degree of indication for epilepsy surgery is determined by taking multiple factors into account. This study aimed to investigate the usefulness of the Specific Consistency Score (SCS), a proposed score for focal epilepsy to rate the indication for epilepsy focal resection. METHODS This retrospective cohort study included patients considered for resective epilepsy surgery in Kyoto University Hospital from 2011 to 2022. Plausible epileptic focus was tentatively defined. Cardinal findings were scored based on specificity and consistency with the estimated laterality and lobe. The total points represented SCS. The association between SCS and the following clinical parameters was assessed by univariate and multivariate analysis: (1) probability of undergoing resective epilepsy surgery, (2) good postoperative seizure outcome (Engel I and II or Engel I only), and (3) lobar concordance between the noninvasively estimated focus and intracranial electroencephalographic (EEG) recordings. RESULTS A total of 131 patients were evaluated. Univariate analysis revealed higher SCS in the (1) epilepsy surgery group (8.4 [95% confidence interval (CI) = 7.8-8.9] vs. 4.9 [95% CI = 4.3-5.5] points; p < .001), (2) good postoperative seizure outcome group (Engel I and II; 8.7 [95% CI = 8.2-9.3] vs. 6.4 [95% CI = 4.5-8.3] points; p = .008), and (3) patients whose focus defined by intracranial EEG matched the noninvasively estimated focus (8.3 [95% CI = 7.3-9.2] vs. 5.4 [95% CI = 3.5-7.3] points; p = .004). Multivariate analysis revealed areas under the curve of .843, .825, and .881 for Parameters 1, 2, and 3, respectively. SIGNIFICANCE SCS provides a reliable index of good indication for resective epilepsy surgery and can be easily available in many institutions not necessarily specializing in epilepsy.
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Affiliation(s)
- Maya Tojima
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihiro Shimotake
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shuichiro Neshige
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Tadashi Okada
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Katsuya Kobayashi
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kiyohide Usami
- Department of Epilepsy, Movement Disorders, and Physiology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masao Matsuhashi
- Department of Epilepsy, Movement Disorders, and Physiology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masayuki Honda
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hirofumi Takeyama
- Department of Respiratory Care and Sleep Control Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takefumi Hitomi
- Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takeshi Yoshida
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Atsushi Yokoyama
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yasutaka Fushimi
- Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tsukasa Ueno
- Department of Psychiatry, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yukihiro Yamao
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takayuki Kikuchi
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takao Namiki
- Department of Mathematics, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Yoshiki Arakawa
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ryosuke Takahashi
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders, and Physiology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Krishnan B, Tousseyn S, Wang ZI, Murakami H, Wu G, Burgess R, Iasemidis L, Najm I, Alexopoulos AV. Novel noninvasive identification of patient-specific epileptic networks in focal epilepsies: Linking single-photon emission computed tomography perfusion during seizures with resting-state magnetoencephalography dynamics. Hum Brain Mapp 2023; 44:1695-1710. [PMID: 36480260 PMCID: PMC9921232 DOI: 10.1002/hbm.26168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 08/31/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022] Open
Abstract
Single-photon emission computed tomography (SPECT) during seizures and magnetoencephalography (MEG) during the interictal state are noninvasive modalities employed in the localization of the epileptogenic zone in patients with drug-resistant focal epilepsy (DRFE). The present study aims to investigate whether there exists a preferentially high MEG functional connectivity (FC) among those regions of the brain that exhibit hyperperfusion or hypoperfusion during seizures. We studied MEG and SPECT data in 30 consecutive DRFE patients who had resective epilepsy surgery. We parcellated each ictal perfusion map into 200 regions of interest (ROIs) and generated ROI time series using source modeling of MEG data. FC between ROIs was quantified using coherence and phase-locking value. We defined a generalized linear model to relate the connectivity of each ROI, ictal perfusion z score, and distance between ROIs. We compared the coefficients relating perfusion z score to FC of each ROI and estimated the connectivity within and between resected and unresected ROIs. We found that perfusion z scores were strongly correlated with the FC of hyper-, and separately, hypoperfused ROIs across patients. High interictal connectivity was observed between hyperperfused brain regions inside and outside the resected area. High connectivity was also observed between regions of ictal hypoperfusion. Importantly, the ictally hypoperfused regions had a low interictal connectivity to regions that became hyperperfused during seizures. We conclude that brain regions exhibiting hyperperfusion during seizures highlight a preferentially connected interictal network, whereas regions of ictal hypoperfusion highlight a separate, discrete and interconnected, interictal network.
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Affiliation(s)
- Balu Krishnan
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Simon Tousseyn
- Academic Center for EpileptologyKempenhaeghe and Maastricht UMC+HeezeThe Netherlands
| | - Zhong Irene Wang
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Hiroatsu Murakami
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Guiyun Wu
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Richard Burgess
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Leonidas Iasemidis
- Department of Translational NeuroscienceBarrow Neurological InstituteScottsdaleArizonaUSA
- Department of NeurologyBarrow Neurological InstituteScottsdaleArizonaUSA
| | - Imad Najm
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
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Schulte F, Bitzer F, Gärtner FC, Bauer T, von Wrede R, Baumgartner T, Rácz A, Borger V, von Oertzen T, Vatter H, Essler M, Surges R, Rüber T. The diagnostic value of ictal SPECT-A retrospective, semiquantitative monocenter study. Epilepsia Open 2023; 8:183-192. [PMID: 36658093 PMCID: PMC9977750 DOI: 10.1002/epi4.12694] [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: 10/26/2022] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE Ictal single photon emission computed tomography (SPECT) can be used as an advanced diagnostic modality to detect the seizure onset zone in the presurgical evaluation of people with epilepsy. In addition to visual assessment (VSA) of ictal and interictal SPECT images, postprocessing methods such as ictal-interictal SPECT analysis using SPM (ISAS) can visualize regional ictal blood flow differences. We aimed to evaluate and differentiate the diagnostic value of VSA and ISAS in the Bonn cohort. METHODS We included 161 people with epilepsy who underwent presurgical evaluation at the University Hospital Bonn between 2008 and 2020 and received ictal and interictal SPECT and ISAS. We retrospectively assigned SPECT findings to one of five categories according to their degree of concordance with the clinical focus hypothesis. RESULTS Seizure onset zones could be identified more likely on a sublobar concordance level by ISAS than by VSA (31% vs. 19% of cases; OR = 1.88; 95% Cl [1.04, 3.42]; P = 0.03). Both VSA and ISAS more often localized a temporal seizure onset zone than an extratemporal one. Neither VSA nor ISAS findings were predicted by the latency between seizure onset and tracer injection (P = 0.75). In people who underwent successful epilepsy surgery, VSA and ISAS indicated the correct resection site in 54% of individuals, while MRI and EEG showed the correct resection localization in 96% and 33% of individuals, respectively. It was more likely to become seizure-free after epilepsy surgery if ISAS or VSA had been successful. There was no MR-negative case with successful surgery, indicating that ictal SPECT is more useful for confirmation than for localization. SIGNIFICANCE The results of the most extensive clinical study of ictal SPECT to date allow an assessment of the diagnostic value of this elaborate examination and emphasize the importance of postprocessing routines.
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Affiliation(s)
- Freya Schulte
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Felix Bitzer
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | | | - Tobias Bauer
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Randi von Wrede
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | | | - Attila Rácz
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Valeri Borger
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Tim von Oertzen
- Department of Neurology 1, Neuromed Campus, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Hartmut Vatter
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Markus Essler
- Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Theodor Rüber
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
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Kunz M, Karschnia P, Borggraefe I, Noachtar S, Tonn JC, Vollmar C. Seizure-free outcome and safety of repeated epilepsy surgery for persistent or recurrent seizures. J Neurosurg 2023; 138:9-18. [PMID: 35901761 DOI: 10.3171/2022.4.jns212753] [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: 12/03/2021] [Accepted: 04/25/2022] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Reoperation may be an option for select patients with unsatisfactory seizure control after their first epilepsy surgery. The aim of this study was to describe the seizure-free outcome and safety of repeated epilepsy surgery in our tertiary referral center. METHODS Thirty-eight patients with focal refractory epilepsy, who underwent repeated epilepsy surgeries and had a minimum follow-up time of 12 months after reoperation, were included. Systematic reevaluation, including comprehensive neuroimaging and noninvasive (n = 38) and invasive (n = 25, 66%) video-electroencephalography monitoring, was performed. Multimodal 3D resection maps were created for individual patients to allow personalized reoperation. RESULTS The median time between the first operation and reoperation was 74 months (range 5-324 months). The median age at reoperation was 34 years (range 1-74 years), and the median follow-up was 38 months (range 13-142 months). Repeat MRI after the first epilepsy surgery showed an epileptogenic lesion in 24 patients (63%). The reoperation was temporal in 18 patients (47%), extratemporal in 9 (24%), and multilobar in 11 (29%). The reoperation was left hemispheric in 24 patients (63%), close to eloquent cortex in 19 (50%), and distant from the initial resection in 8 (21%). Following reoperation, 27 patients (71%) became seizure free (Engel class I), while 11 (29%) continued to have seizures. There were trends toward better outcome in temporal lobe epilepsy and for unilobar resections adjacent to the initial surgery, but there was no difference between MRI lesional and nonlesional patients. In all subgroups, Engel class I outcome was at least 50%. Perioperative complications occurred in 4 patients (11%), with no fatalities. CONCLUSIONS Reoperation for refractory focal epilepsy is an effective and safe option in patients with persistent or recurrent seizures after initial epilepsy surgery. A thorough presurgical reevaluation is essential for favorable outcome.
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Affiliation(s)
- Mathias Kunz
- 1Department of Neurosurgery, University Hospital of the Ludwig-Maximilians-University of Munich
| | - Philipp Karschnia
- 1Department of Neurosurgery, University Hospital of the Ludwig-Maximilians-University of Munich
| | - Ingo Borggraefe
- 2Department of Pediatrics, Division of Pediatric Neurology and Developmental Medicine, University Hospital of the Ludwig-Maximilians-University of Munich; and
| | - Soheyl Noachtar
- 3Department of Neurology, Epilepsy Center, University Hospital of the Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Joerg-Christian Tonn
- 1Department of Neurosurgery, University Hospital of the Ludwig-Maximilians-University of Munich
| | - Christian Vollmar
- 3Department of Neurology, Epilepsy Center, University Hospital of the Ludwig-Maximilians-University of Munich, Munich, Germany
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Wang R, Zhu W, Liang G, Xu J, Guo J, Wang L. Animal models for epileptic foci localization, seizure detection, and prediction by electrical impedance tomography. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2022; 13:e1619. [PMID: 36093634 DOI: 10.1002/wcs.1619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/08/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Surgical resection of lesions and closed-loop suppression are the two main treatment options for patients with refractory epilepsy whose symptoms cannot be managed with medicines. Unfortunately, failures in foci localization and seizure prediction are constraining these treatments. Electrical impedance tomography (EIT), sensitive to impedance changes caused by blood flow or cell swelling, is a potential new way to locate epileptic foci and predict seizures. Animal validation is a necessary research process before EIT can be used in clinical practice, but it is unclear which among the many animal epilepsy models is most suited to this task. The selection of an animal model of epilepsy that is similar to human seizures and can be adapted to EIT is important for the accuracy and reliability of EIT research results. This study provides an overview of the animal models of epilepsy that have been used in research on the use of EIT to locate the foci or predict seizures; discusses the advantages and disadvantages of these models regarding inducement by chemical convulsant and electrical stimulation; and finally proposes optimal animal models of epilepsy to obtain more convincing research results for foci localization and seizure prediction by EIT. The ultimate goal of this study is to facilitate the development of new treatments for patients with refractory epilepsy. This article is categorized under: Neuroscience > Clinical Neuroscience Psychology > Brain Function and Dysfunction.
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Affiliation(s)
- Rong Wang
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Wenjing Zhu
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Guohua Liang
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Jiaming Xu
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Jie Guo
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Lei Wang
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
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Shoeibi A, Moridian P, Khodatars M, Ghassemi N, Jafari M, Alizadehsani R, Kong Y, Gorriz JM, Ramírez J, Khosravi A, Nahavandi S, Acharya UR. An overview of deep learning techniques for epileptic seizures detection and prediction based on neuroimaging modalities: Methods, challenges, and future works. Comput Biol Med 2022; 149:106053. [DOI: 10.1016/j.compbiomed.2022.106053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 08/17/2022] [Accepted: 08/17/2022] [Indexed: 02/01/2023]
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Yossofzai O, Fallah A, Maniquis C, Wang S, Ragheb J, Weil AG, Brunette-Clement T, Andrade A, Ibrahim GM, Mitsakakis N, Widjaja E. Development and validation of machine learning models for prediction of seizure outcome after pediatric epilepsy surgery. Epilepsia 2022; 63:1956-1969. [PMID: 35661152 DOI: 10.1111/epi.17320] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVE There is substantial variability in reported seizure outcome following pediatric epilepsy surgery, and lack of individualized predictive tools that could evaluate the probability of seizure freedom postsurgery. The aim of this study was to develop and validate a supervised machine learning (ML) model for predicting seizure freedom after pediatric epilepsy surgery. METHODS This is a multicenter retrospective study of children who underwent epilepsy surgery at five pediatric epilepsy centers in North America. Clinical information, diagnostic investigations, and surgical characteristics were collected, and used as features to predict seizure-free outcome 1 year after surgery. The dataset was split randomly into 80% training and 20% testing data. Thirty-five combinations of five feature sets with seven ML classifiers were assessed on the training cohort using 10-fold cross-validation for model development. The performance of the optimal combination of ML classifier and feature set was evaluated in the testing cohort, and compared with logistic regression, a classical statistical approach. RESULTS Of the 801 patients included, 61.3% were seizure-free 1 year postsurgery. During model development, the best combination was XGBoost ML algorithm with five features from the univariate feature set, including number of antiseizure medications, magnetic resonance imaging lesion, age at seizure onset, video-electroencephalography concordance, and surgery type, with a mean area under the curve (AUC) of .73 (95% confidence interval [CI] = .69-.77). The combination of XGBoost and univariate feature set was then evaluated on the testing cohort and achieved an AUC of .74 (95% CI = .66-.82; sensitivity = .87, 95% CI = .81-.94; specificity = .58, 95% CI = .47-.71). The XGBoost model outperformed the logistic regression model (AUC = .72, 95% CI = .63-.80; sensitivity = .72, 95% CI = .63-.82; specificity = .66, 95% CI = .53-.77) in the testing cohort (p = .005). SIGNIFICANCE This study identified important features and validated an ML algorithm, XGBoost, for predicting the probability of seizure freedom after pediatric epilepsy surgery. Improved prognostication of epilepsy surgery is critical for presurgical counseling and will inform treatment decisions.
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Affiliation(s)
- Omar Yossofzai
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Aria Fallah
- Department of Neurosurgery, University of California, Los Angeles Mattel Children's Hospital, Los Angeles, California, USA
| | - Cassia Maniquis
- Department of Neurosurgery, University of California, Los Angeles Mattel Children's Hospital, Los Angeles, California, USA
| | - Shelly Wang
- Division of Neurosurgery, Brain Institute, Nicklaus Children's Hospital, Miami, Florida, USA
| | - John Ragheb
- Division of Neurosurgery, Brain Institute, Nicklaus Children's Hospital, Miami, Florida, USA
| | - Alexander G Weil
- Department of Neurosurgery, Sainte-Justine University Hospital Center, Montreal, Quebec, Canada
| | | | - Andrea Andrade
- Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - George M Ibrahim
- Department of Neurosurgery, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Nicholas Mitsakakis
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Elysa Widjaja
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.,Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada.,Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
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Prognostic value of high-frequency oscillations combined with multimodal imaging methods for epilepsy surgery. Chin Med J (Engl) 2021; 135:1087-1095. [PMID: 35773966 PMCID: PMC9276102 DOI: 10.1097/cm9.0000000000001909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background: The combination of high-frequency oscillations (HFOs) with single-mode imaging methods has been proved useful in identifying epileptogenic zones, whereas few studies have examined HFOs combined with multimodal imaging methods. The aim of this study was to evaluate the prognostic value of ripples, an HFO subtype with a frequency of 80 to 200 Hz is combined with multimodal imaging methods in predicting epilepsy surgery outcome. Methods: HFOs were analyzed in 21 consecutive medically refractory epilepsy patients who underwent epilepsy surgery. All patients underwent positron emission tomography (PET) and deep electrode implantation for stereo-electroencephalography (SEEG); 11 patients underwent magnetoencephalography (MEG). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in predicting surgical outcome were calculated for ripples combined with PET, MEG, both PET and MEG, and PET combined with MEG. Kaplan-Meier survival analyses were conducted in each group to estimate prognostic value. Results: The study included 13 men and 8 women. Accuracy for ripples, PET, and MEG alone in predicting surgical outcome was 42.9%, 42.9%, and 81.8%, respectively. Accuracy for ripples combined with PET and MEG was the highest. Resection of regions identified by ripples, MEG dipoles, and combined PET findings was significantly associated with better surgical outcome (P < 0.05). Conclusions: Intracranial electrodes are essential to detect regions which generate ripples and to remove these areas which indicate good surgical outcome for medically intractable epilepsy. With the assistance of presurgical noninvasive imaging examinations, PET and MEG, for example, the SEEG electrodes would identify epileptogenic regions more effectively.
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Iachim E, Vespa S, Baroumand AG, Danthine V, Vrielynck P, de Tourtchaninoff M, Fierain A, Ribeiro Vaz JG, Raftopoulos C, Ferrao Santos S, van Mierlo P, El Tahry R. Automated electrical source imaging with scalp EEG to define the insular irritative zone: Comparison with simultaneous intracranial EEG. Clin Neurophysiol 2021; 132:2965-2978. [PMID: 34715421 DOI: 10.1016/j.clinph.2021.09.004] [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: 04/07/2021] [Revised: 08/13/2021] [Accepted: 09/16/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate the accuracy of automatedinterictallow-density electrical source imaging (LD-ESI) to define the insular irritative zone (IZ) by comparing the simultaneous interictal ESI localization with the SEEG interictal activity. METHODS Long-term simultaneous scalp electroencephalography (EEG) and stereo-EEG (SEEG) with at least one depth electrode exploring the operculo-insular region(s) were analyzed. Automated interictal ESI was performed on the scalp EEG using standardized low-resolution brain electromagnetic tomography (sLORETA) and individual head models. A two-step analysis was performed: i) sublobar concordance betweencluster-based ESI localization and SEEG-based IZ; ii) time-locked ESI-/SEEG analysis. Diagnostic accuracy values were calculated using SEEG as reference standard. Subgroup analysis wascarried out, based onthe involvement of insular contacts in the seizure onset and patterns of insular interictal activity. RESULTS Thirty patients were included in the study. ESI showed an overall accuracy of 53% (C.I. 29-76%). Sensitivity and specificity were calculated as 53% (C.I. 29-76%), 55% (C.I. 23-83%) respectively. Higher accuracy was found in patients with frequent and dominant interictal insular spikes. CONCLUSIONS LD-ESI defines with good accuracy the insular implication in the IZ, which is not possible with classical interictalscalpEEG interpretation. SIGNIFICANCE Automated LD-ESI may be a valuable additional tool to characterize the epileptogenic zone in epilepsies with suspected insular involvement.
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Affiliation(s)
- Evelina Iachim
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania; Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Simone Vespa
- Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium.
| | - Amir G Baroumand
- Medical Image and Signal Processing Group (MEDISIP), Department of Electronics and Information Systems, Ghent University, Ghent, Belgium; Epilog NV, Ghent, Belgium
| | - Venethia Danthine
- Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium
| | - Pascal Vrielynck
- Epileptology and Clinical Neurophysiology, Centre Neurologique William Lennox, Ottignies, Belgium
| | - Marianne de Tourtchaninoff
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Alexane Fierain
- Epileptology and Clinical Neurophysiology, Centre Neurologique William Lennox, Ottignies, Belgium
| | - Jose Geraldo Ribeiro Vaz
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | | | - Susana Ferrao Santos
- Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium; Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Pieter van Mierlo
- Medical Image and Signal Processing Group (MEDISIP), Department of Electronics and Information Systems, Ghent University, Ghent, Belgium; Epilog NV, Ghent, Belgium
| | - Riëm El Tahry
- Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium; Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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Laohathai C, Ebersole JS, Mosher JC, Bagić AI, Sumida A, Von Allmen G, Funke ME. Practical Fundamentals of Clinical MEG Interpretation in Epilepsy. Front Neurol 2021; 12:722986. [PMID: 34721261 PMCID: PMC8551575 DOI: 10.3389/fneur.2021.722986] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/06/2021] [Indexed: 11/29/2022] Open
Abstract
Magnetoencephalography (MEG) is a neurophysiologic test that offers a functional localization of epileptic sources in patients considered for epilepsy surgery. The understanding of clinical MEG concepts, and the interpretation of these clinical studies, are very involving processes that demand both clinical and procedural expertise. One of the major obstacles in acquiring necessary proficiency is the scarcity of fundamental clinical literature. To fill this knowledge gap, this review aims to explain the basic practical concepts of clinical MEG relevant to epilepsy with an emphasis on single equivalent dipole (sECD), which is one the most clinically validated and ubiquitously used source localization method, and illustrate and explain the regional topology and source dynamics relevant for clinical interpretation of MEG-EEG.
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Affiliation(s)
- Christopher Laohathai
- Division of Child Neurology, Department of Pediatrics, McGovern Medical School at UTHealth, Houston, TX, United States
- Department of Neurology, Saint Louis University, Saint Louis, MO, United States
| | - John S. Ebersole
- Northeast Regional Epilepsy Group, Atlantic Health Neuroscience Institute, Summit, NJ, United States
| | - John C. Mosher
- Department of Neurology, McGovern Medical School at UTHealth, Houston, TX, United States
| | - Anto I. Bagić
- University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), Department of Neurology, University of Pittsburgh Medical Center, Pittsburg, PA, United States
| | - Ai Sumida
- Department of Neurology, McGovern Medical School at UTHealth, Houston, TX, United States
| | - Gretchen Von Allmen
- Division of Child Neurology, Department of Pediatrics, McGovern Medical School at UTHealth, Houston, TX, United States
| | - Michael E. Funke
- Division of Child Neurology, Department of Pediatrics, McGovern Medical School at UTHealth, Houston, TX, United States
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11
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Madaan P, Gupta A, Gulati S. Pediatric Epilepsy Surgery: Indications and Evaluation. Indian J Pediatr 2021; 88:1000-1006. [PMID: 33740232 DOI: 10.1007/s12098-021-03668-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/12/2021] [Indexed: 12/26/2022]
Abstract
Epilepsy is a common neurological condition in children. It is usually amenable to drug therapy. However, nearly one-third of patients may be refractory to antiseizure drugs. Poor compliance and nonepileptic events should be ruled out as possible causes of drug-resistant epilepsy (DRE). After failing adequate trials of two appropriate antiseizure drugs, patients with focal DRE or poorly classifiable epilepsy or epileptic encephalopathy with focal electro-clinical features should be worked up for surgical candidacy. A randomized controlled trial provided a class I evidence for epilepsy surgery in pediatric DRE. Pre-surgical screening workup typically includes a high-resolution epilepsy protocol brain magnetic resonance imaging (MRI) and a high-quality in-patient video electroencephalography evaluation. Advanced investigations such as positron emission tomography (PET), single-photon emission computed tomography (SPECT), and magnetoencephalography (MEG) may be required in selected cases especially when brain MRI is normal, and further evidence for anatomo-electro-clinical concordance is necessary to refine candidacy for surgery and surgical strategy. Some children may also need functional MRI to map eloquent regions of interest such as motor, sensory, and language functions to avoid unacceptable neurological deficits after surgery. Selected children may need invasive long-term electroencephalographic monitoring using stereotactically implanted intracranial depth electrodes or subdural grids. Surgical options include resective surgeries (lesionectomy, lobectomy, multilobar resections) and disconnective surgeries (corpus callosotomy, etc.) with the potential to obtain seizure freedom. Other surgical procedures, typically considered to be palliative are neuromodulation [deep brain stimulation (DBS), vagal nerve stimulation (VNS), and responsive neural stimulation (RNS)]. DBS and RNS are currently not approved in children. Pediatric DRE should be evaluated early considering the risk of epileptic encephalopathy and negative impact on cognition.
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Affiliation(s)
- Priyanka Madaan
- Pediatric Neurology Unit, Department of Pediatrics, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Ajay Gupta
- Pediatric Epilepsy, Epilepsy Center, Department of Neurology/Neurological Institute, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Sheffali Gulati
- Center of Excellence & Advanced Research on Childhood Neurodevelopmental Disorders, Child Neurology Division, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, 110029, India.
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12
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Jin L, Choi JY, Bulacio J, Alexopoulos AV, Burgess RC, Murakami H, Bingaman W, Najm I, Wang ZI. Multimodal Image Integration for Epilepsy Presurgical Evaluation: A Clinical Workflow. Front Neurol 2021; 12:709400. [PMID: 34421808 PMCID: PMC8372749 DOI: 10.3389/fneur.2021.709400] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/25/2021] [Indexed: 12/02/2022] Open
Abstract
Multimodal image integration (MMII) is a promising tool to help delineate the epileptogenic zone (EZ) in patients with medically intractable focal epilepsies undergoing presurgical evaluation. We report here the detailed methodology of MMII and an overview of the utility of MMII at the Cleveland Clinic Epilepsy Center from 2014 to 2018, exemplified by illustrative cases. The image integration was performed using the Curry platform (Compumedics Neuroscan™, Charlotte, NC, USA), including all available diagnostic modalities such as Magnetic resonance imaging (MRI), Positron Emission Tomography (PET), single-photon emission computed tomography (SPECT) and Magnetoencephalography (MEG), with additional capability of trajectory planning for intracranial EEG (ICEEG), particularly stereo-EEG (SEEG), as well as surgical resection planning. In the 5-year time span, 467 patients underwent MMII; of them, 98 patients (21%) had a history of prior neurosurgery and recurring seizures. Of the 467 patients, 425 patients underwent ICEEG implantation with further CT co-registration to identify the electrode locations. A total of 351 patients eventually underwent surgery after MMII, including 197 patients (56%) with non-lesional MRI and 223 patients (64%) with extra-temporal lobe epilepsy. Among 269 patients with 1-year post-operative follow up, 134 patients (50%) had remained completely seizure-free. The most common histopathological finding is focal cortical dysplasia. Our study illustrates the usefulness of MMII to enhance SEEG electrode trajectory planning, assist non-invasive/invasive data interpretation, plan resection strategy, and re-evaluate surgical failures. Information presented by MMII is essential to the understanding of the anatomo-functional-electro-clinical correlations in individual cases, which leads to the ultimate success of presurgical evaluation of patients with medically intractable focal epilepsies.
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Affiliation(s)
- Liri Jin
- Department of Neurology, Peking Union Medical College Hospital, Beijing, China.,Epilepsy Center, Cleveland Clinic, Cleveland, OH, United States
| | - Joon Yul Choi
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, United States
| | - Juan Bulacio
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, United States
| | | | | | | | - William Bingaman
- Department of Neurosurgery, Cleveland Clinic, Cleveland, OH, United States
| | - Imad Najm
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, United States
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13
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Tripathi M, Kaur K, Ramanujam B, Viswanathan V, Bharti K, Singh G, Singh V, Garg A, Bal CS, Tripathi M, Sharma MC, Pandey R, Dash D, Mandal P, Chandra PS. Diagnostic added value of interictal magnetic source imaging in presurgical evaluation of persons with epilepsy: A prospective blinded study. Eur J Neurol 2021; 28:2940-2951. [PMID: 34124810 DOI: 10.1111/ene.14935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/27/2021] [Accepted: 05/06/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE In presurgical evaluation for epilepsy surgery, information is sourced from various imaging modalities to accurately localize the epileptogenic zone. Magnetoencephalography (MEG) is a newer noninvasive technique for localization. However, there is limited literature to evaluate if MEG provides additional advantage over the conventional imaging modalities in clinical decision making. The objective of this study was to assess the diagnostic added value of MEG in decision making before epilepsy surgery. METHOD This was a prospective observational study. Patients underwent 3 h of recording in a MEG scanner, and the resulting localizations were compared with other complimentary investigations. Added value of MEG (considered separately from high-density electroencephalography) was defined as the frequency of cases in which (i) the information provided by magnetic source imaging (MSI) avoided implantation of intracranial electrodes and the patient was directly cleared for surgery, and (ii) MSI indicated additional substrates for implantation of intracranial electrodes. Postoperative seizure freedom was used as the diagnostic reference by which to measure the localizing accuracy of MSI. RESULTS A total of 102 patients underwent epilepsy surgery. MEG provided nonredundant information, which contributed to deciding the course of surgery in 33% of the patients, and prevented intracranial recordings in 19%. A total of 76% of the patients underwent surgical resection in sublobes concordant with MSI localization, and the diagnostic odds ratio for good (Engel I) outcome in these patients was 2.3 (95% confidence interval 0.68, 7.86; p = 0.183) after long-term follow-up of 36 months. CONCLUSION Magnetic source imaging yields additional useful information which can significantly alter as well as improve the surgical strategy for persons with epilepsy.
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Affiliation(s)
- Manjari Tripathi
- Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Kirandeep Kaur
- Neurology, All India Institute of Medical Sciences, New Delhi, India.,MEG Facility, National Brain Research Institute, Manesar, India
| | | | - Vibhin Viswanathan
- Neurosurgery, All India Institute of Medical Sciences, New Delhi, India.,MEG Resource Facility, Collaborative Project Between AIIMS & NBRC, National Brain Research Center, Manesar, India
| | - Kamal Bharti
- MEG Resource Facility, Collaborative Project Between AIIMS & NBRC, National Brain Research Center, Manesar, India
| | - Gaurav Singh
- MEG Resource Facility, Collaborative Project Between AIIMS & NBRC, National Brain Research Center, Manesar, India
| | - Vivek Singh
- MEG Resource Facility, Collaborative Project Between AIIMS & NBRC, National Brain Research Center, Manesar, India
| | - Ajay Garg
- Neuroradiology, All India Institute of Medical Sciences, New Delhi, India
| | - Chandra Sekhar Bal
- Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Madhavi Tripathi
- Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
| | | | - Ravindra Pandey
- Biostatistics, All India Institute of Medical Sciences, New Delhi, India
| | - Deepa Dash
- Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Pravat Mandal
- MEG Resource Facility, Collaborative Project Between AIIMS & NBRC, National Brain Research Center, Manesar, India
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14
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Otsubo H, Ogawa H, Pang E, Wong SM, Ibrahim GM, Widjaja E. A review of magnetoencephalography use in pediatric epilepsy: an update on best practice. Expert Rev Neurother 2021; 21:1225-1240. [PMID: 33780318 DOI: 10.1080/14737175.2021.1910024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Introduction: Magnetoencephalography (MEG) is a noninvasive technique that is used for presurgical evaluation of children with drug-resistant epilepsy (DRE).Areas covered: The contributions of MEG for localizing the epileptogenic zone are discussed, in particular in extra-temporal lobe epilepsy and focal cortical dysplasia, which are common in children, as well as in difficult to localize epilepsy such as operculo-insular epilepsy. Further, the authors review current evidence on MEG for mapping eloquent cortex, its performance, application in clinical practice, and potential challenges.Expert opinion: MEG could change the clinical management of children with DRE by directing placement of intracranial electrodes thereby enhancing their yield. With improved identification of a circumscribed epileptogenic zone, MEG could render more patients as suitable candidates for epilepsy surgery and increase utilization of surgery.
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Affiliation(s)
- Hiroshi Otsubo
- Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
| | - Hiroshi Ogawa
- Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
| | - Elizabeth Pang
- Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada.,Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada
| | - Simeon M Wong
- Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada
| | - George M Ibrahim
- Division of Neurosurgery, Hospital for Sick Children, Toronto, Canada.,Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
| | - Elysa Widjaja
- Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada.,Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Canada.,Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
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15
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Kaur K, Garg A, Tripathi M, Chandra SP, Singh G, Viswanathan V, Bharti K, Singh V, Ramanujam B, Bal CS, Sharma MC, Pandey R, Vibha D, Singh RK, Mandal PK, Tripathi M. Comparative contribution of magnetoencephalography (MEG) and single-photon emission computed tomography (SPECT) in pre-operative localization for epilepsy surgery: A prospective blinded study. Seizure 2021; 86:181-188. [PMID: 33647809 DOI: 10.1016/j.seizure.2021.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 02/01/2021] [Accepted: 02/03/2021] [Indexed: 01/20/2023] Open
Abstract
PURPOSE The aim of this study was to compare the diagnostic value and accuracy of ictal SPECT and inter-ictal magnetoencephalography (MEG) in localizing the site for surgery in persons with drug resistant epilepsy. METHOD This was a prospective observational study. Patients expected to undergo epilepsy surgery were enrolled consecutively and the localization results from different imaging modalities were discussed in an epilepsy surgery meet. Odds ratio of good outcome (Engel I) were calculated in patients who underwent surgery in concordance with MEG and SPECT findings. Post-surgical seizure freedom lasting at least 36 months or more was considered the gold standard for determining the diagnostic output of SPECT and MEG. RESULTS MEG and SPECT were performed in 101 and 57 patients respectively. In 45 patients SPECT could not be done due to delay in injection or technical factors. The accuracy of MEG and SPECT in localizing the epileptogenic zone was found to be 74.26 % and 78.57 % respectively. The diagnostic odds ratio for Engel I surgical outcome was reported as 2.43 and 5.0 for MEG and SPECT respectively. The diagnostic odds ratio for MEG in whom SPECT was non-informative was found to be 6.57 [95 % CI 1.1, 39.24], although it was not significantly associated with good surgical outcome. MEG was useful in indicating sites for SEEG implantation. CONCLUSION SPECT was found to be non-informative for most patients, but reported better diagnostic output than MEG. MEG may be a useful alternative for patients in whom SPECT cannot be done or was non-localizing.
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Affiliation(s)
- Kirandeep Kaur
- Dept of Neurology, All India Institute of Medical Sciences, New Delhi, India; MEG Facility, National Brain Research Institute, Manesar, India
| | - Ajay Garg
- Dept of Neuroradiology, All India Institute of Medical Sciences, New Delhi, India
| | - Madhavi Tripathi
- Dept of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Sarat P Chandra
- Dept of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
| | - Gaurav Singh
- MEG Facility, National Brain Research Institute, Manesar, India
| | | | - Kamal Bharti
- MEG Facility, National Brain Research Institute, Manesar, India
| | - Vivek Singh
- MEG Facility, National Brain Research Institute, Manesar, India
| | - Bhargavi Ramanujam
- Dept of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Chandra Sekhar Bal
- Dept of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
| | - Mehar Chand Sharma
- Dept of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Ravindra Pandey
- Dept of Biostatistics, All India Institute of Medical Sciences, New Delhi, India
| | - Deepti Vibha
- Dept of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Rajesh Kumar Singh
- Dept of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | | | - Manjari Tripathi
- Dept of Neurology, All India Institute of Medical Sciences, New Delhi, India.
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16
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Krishnan B, Tousseyn S, Nayak CS, Aung T, Kheder A, Wang ZI, Wu G, Gonzalez-Martinez J, Nair D, Burgess R, Iasemidis L, Najm I, Bulacio J, Alexopoulos AV. Neurovascular networks in epilepsy: Correlating ictal blood perfusion with intracranial electrophysiology. Neuroimage 2021; 231:117838. [PMID: 33577938 DOI: 10.1016/j.neuroimage.2021.117838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/21/2020] [Accepted: 02/01/2021] [Indexed: 11/25/2022] Open
Abstract
Perfusion patterns observed in Subtraction Ictal SPECT Co-registered to MRI (SISCOM) assist in focus localization and surgical planning for patients with medically intractable focal epilepsy. While the localizing value of SISCOM has been widely investigated, its relationship to the underlying electrophysiology has not been extensively studied and is therefore not well understood. In the present study, we set to investigate this relationship in a cohort of 70 consecutive patients who underwent ictal and interictal SPECT studies and subsequent stereo-electroencephalography (SEEG) monitoring for localization of the epileptogenic focus and surgical intervention. Seizures recorded during SEEG evaluation (SEEG seizures) were matched to semiologically-similar seizures during the preoperative ictal SPECT evaluation (SPECT seizures) by comparing the semiological changes in the course of each seizure. The spectral changes of the ictal SEEG with respect to interictal ones over 7 traditional frequency bands (0.1 to 150Hz) were analyzed at each SEEG site. Neurovascular (SEEG/SPECT) relations were assessed by comparing the estimated spectral power density changes of the SEEG at each site with the perfusion changes (SISCOM z-scores) estimated from the acquired SISCOM map at that site. Across patients, a significant correlation (p<0.05) was observed between spectral changes during the SEEG seizure and SISCOM perfusion z-scores. Brain sites with high perfusion z-score exhibited higher increased SEEG power in theta to ripple frequency bands with concurrent suppression in delta and theta frequency bands compared to regions with lower perfusion z-score. The dynamics of the correlation of SISCOM perfusion and SEEG spectral power from ictal onset to seizure end and immediate postictal period were also derived. Forty-six (46) of the 70 patients underwent resective epilepsy surgery. SISCOM z-score and power increase in beta to ripple frequency bands were significantly higher in resected than non-resected sites in the patients who were seizure-free following surgery. This study provides for the first time concrete evidence that both hyper-perfusion and hypo-perfusion patterns observed in SISCOM maps have strong electrophysiological underpinnings, and that integration of the information from SISCOM and SEEG can shed light on the location and dynamics of the underlying epileptic brain networks, and thus advance our anatomo-electro-clinical understanding and approaches to targeted diagnostic and therapeutic interventions.
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Affiliation(s)
- Balu Krishnan
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA.
| | - Simon Tousseyn
- Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands
| | - Chetan Sateesh Nayak
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Thandar Aung
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Ammar Kheder
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Z Irene Wang
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Guiyun Wu
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Jorge Gonzalez-Martinez
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Dileep Nair
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Richard Burgess
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Leonidas Iasemidis
- Center for Biomedical Engineering and Rehabilitation Science, Louisiana Tech University, Ruston, LA, USA
| | - Imad Najm
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Juan Bulacio
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Andreas V Alexopoulos
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
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17
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Bagić AI, Funke ME, Kirsch HE, Tenney JR, Zillgitt AJ, Burgess RC. The 10 Common Evidence-Supported Indications for MEG in Epilepsy Surgery: An Illustrated Compendium. J Clin Neurophysiol 2021; 37:483-497. [PMID: 33165222 DOI: 10.1097/wnp.0000000000000726] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Unfamiliarity with the indications for and benefits of magnetoencephalography (MEG) persists, even in the epilepsy community, and hinders its acceptance to clinical practice, despite the evidence. The wide treatment gap for patients with drug-resistant epilepsy and immense underutilization of epilepsy surgery had similar effects. Thus, educating referring physicians (epileptologists, neurologists, and neurosurgeons) both about the value of epilepsy surgery and about the potential benefits of MEG can achieve synergy and greatly improve the process of selecting surgical candidates. As a practical step toward a comprehensive educational process to benefit potential MEG users, current MEG referrers, and newcomers to MEG, the authors have elected to provide an illustrated guide to 10 everyday situations where MEG can help in the evaluation of people with drug-resistant epilepsy. They are as follows: (1) lacking or imprecise hypothesis regarding a seizure onset; (2) negative MRI with a mesial temporal onset suspected; (3) multiple lesions on MRI; (4) large lesion on MRI; (5) diagnostic or therapeutic reoperation; (6) ambiguous EEG findings suggestive of "bilateral" or "generalized" pattern; (7) intrasylvian onset suspected; (8) interhemispheric onset suspected; (9) insular onset suspected; and (10) negative (i.e., spikeless) EEG. Only their practical implementation and furtherance of personal and collective education will lead to the potentially impactful synergy of the two-MEG and epilepsy surgery. Thus, while fulfilling our mission as physicians, we must not forget that ignoring the wealth of evidence about the vast underutilization of epilepsy surgery - and about the usefulness and value of MEG in selecting surgical candidates - is far from benign neglect.
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Affiliation(s)
- Anto I Bagić
- University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), Department of Neurology, University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, U.S.A
| | - Michael E Funke
- MEG Center, McGovern Medical School, UT Houston, Houston, Texas, U.S.A
| | - Heidi E Kirsch
- UCSF Biomagnetic Imaging Laboratory, UCSF, San Francisco, California, U.S.A
| | - Jeffrey R Tenney
- MEG Center, Cincinnati Children's Hospital Medical Center , Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, U.S.A
| | - Andrew J Zillgitt
- Department of Neurology, Beaumont Health Adult Comprehensive Epilepsy Center, Neurosicence Center, Royal Oak, Michigan, U.S.A.; and
| | - Richard C Burgess
- Magnetoencephalography Laboratory, Cleveland Clinic Epilepsy Center, Cleveland, Ohio, U.S.A
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18
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Shawarba J, Kaspar B, Rampp S, Winter F, Coras R, Blumcke I, Hamer H, Buchfelder M, Roessler K. Advantages of magnetoencephalography, neuronavigation and intraoperative MRI in epilepsy surgery re-operations. Neurol Res 2021; 43:434-439. [PMID: 33402062 DOI: 10.1080/01616412.2020.1866384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Objective: Management of patients after failed epilepsy surgery is still challenging. Advanced diagnostic and intraoperative tools including magneto-encephalography (MEG) as well as neuronavigation and intraoperative magnetic resonance imaging (iopMRI) may contribute to a better postoperative seizure outcome in this patient group.Methods: We retrospectively analyzed consecutive patients after reoperation of failed epilepsy surgery for medically refractory epilepsy at the University of Erlangen between 1988 and 2017. Inclusion criteria for patients were available MEG, neuronavigation and iopMRI data. The Engel scale was used to categorize seizure outcome.Results: We report on 27 consecutive patients (13 female/14 male mean age at first surgery 29.4 years) who had operative revision of the first resection after failed epilepsy surgery. An improved seizure outcome postoperatively was observed in 78% of patients (p < 0.001) with 55% seizure free (Engel I) patients after a mean follow-up time of 4.9 years. In detail, 80% of lesional cases were seizure free compared to 59% of MRI negative patients. Localizing MEG spike activity in the vicinity of the first resection cavity was present in 12 of 27 patients (44%) corresponding to 83% (10/12) of MEG localizing spike patients having advanced seizure outcome after operative revision.Conclusion: Re-operation after failed surgery in refractory epilepsy may lead to a better seizure outcome in the majority of patients. Preoperative MEG may support the decision for surgery and may facilitate targeting epileptogenic tissue for re-resection by employing navigation and iopMR imaging.
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Affiliation(s)
- Julia Shawarba
- Neurosurgical Department, Erlangen University Clinic, Erlangen, Germany
| | - Burkhard Kaspar
- Neurological Department, Erlangen University Clinic, Erlangen, Germany
| | - Stefan Rampp
- Neurosurgical Department, Erlangen University Clinic, Erlangen, Germany
| | - Fabian Winter
- Neurosurgical Clinic, Vienna Medical University, Vienna, Austria
| | - Roland Coras
- Neuropathological Institute, Erlangen University Clinic, Erlangen, Germany
| | - Ingmar Blumcke
- Neuropathological Institute, Erlangen University Clinic, Erlangen, Germany
| | - Hajo Hamer
- Neurological Department, Erlangen University Clinic, Erlangen, Germany
| | | | - Karl Roessler
- Neurosurgical Department, Erlangen University Clinic, Erlangen, Germany.,Neurosurgical Clinic, Vienna Medical University, Vienna, Austria
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19
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Otsuka K, Egawa K, Fujima N, Kudo K, Terae S, Nakajima M, Ito T, Yagyu K, Shiraishi H. Reinterpretation of magnetic resonance imaging findings with magnetoencephalography can improve the accuracy of detecting epileptogenic cortical lesions. Epilepsy Behav 2021; 114:107516. [PMID: 33323336 DOI: 10.1016/j.yebeh.2020.107516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/10/2020] [Accepted: 09/20/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE This study examined whether the application of magnetoencephalography (MEG) to interpret magnetic resonance imaging (MRI) findings can aid the diagnosis of intractable epilepsy caused by organic brain lesions. METHODS This study included 51 patients with epilepsy who had MEG clusters but whose initial MRI findings were interpreted as being negative for organic lesions. Three board-certified radiologists reinterpreted the MRI findings, utilizing the MEG findings as a guide. The degree to which the reinterpretation of the imaging results identified an organic lesion was rated on a 5-point scale. RESULTS Reinterpretation of the MRI data with MEG guidance helped detect an abnormality by at least one radiologist in 18 of the 51 patients (35.2%) with symptomatic localization-related epilepsy. A surgery was performed in 7 of the 51 patients, and histopathological analysis results identified focal cortical dysplasia in 5 patients (Ia: 1, IIa: 2, unknown: 2), hippocampal sclerosis in 1 patient, and dysplastic neurons/gliosis in 1 patient. CONCLUSIONS The results of this study highlight the potential diagnostic applications of MEG to detect organic epileptogenic lesions, particularly when radiological visualization is difficult with MRI alone.
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Affiliation(s)
- Kosuke Otsuka
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Noriyuki Fujima
- Department of Diagnostic and Interventional Radiology, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Kohsuke Kudo
- Department of Diagnostic and Interventional Radiology, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Satoshi Terae
- Department of Diagnostic Radiology, Sapporo City General Hospital, North 11, West 13, Chuou-ku, Sapporo, Hokkaido 060-8604, Japan
| | - Midori Nakajima
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Tomoshiro Ito
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Kazuyori Yagyu
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan; Department of Child and Adolescent Psychiatry, Hokkaido University Hospital, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15, West 7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan.
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Vespa S, Baroumand AG, Ferrao Santos S, Vrielynck P, de Tourtchaninoff M, Feys O, Strobbe G, Raftopoulos C, van Mierlo P, El Tahry R. Ictal EEG source imaging and connectivity to localize the seizure onset zone in extratemporal lobe epilepsy. Seizure 2020; 78:18-30. [DOI: 10.1016/j.seizure.2020.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/27/2020] [Accepted: 03/01/2020] [Indexed: 12/16/2022] Open
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Choi JY, Wang ZI. Merging Magnetoencephalography into Epilepsy Presurgical Work-up Under the Framework of Multimodal Integration. Neuroimaging Clin N Am 2020; 30:249-259. [PMID: 32336411 DOI: 10.1016/j.nic.2020.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Multimodal image integration is the procedure that puts together imaging data from multiple sources into the same space by a computerized registration process. This procedure is relevant to patients with difficult-to-localize epilepsy undergoing presurgical evaluation, who typically have many tests performed, including MR imaging, PET, ictal single-photon emission computed tomography, magnetoencephalography (MEG), and intracranial electroencephalogram (EEG). This article describes the methodology of such integration, focusing on integration of MEG. Also discussed is the clinical value of integration of MEG, in terms of planning of intracranial EEG implantation, interpretation of intracranial EEG data, planning of final resection, and addressing surgical failures.
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Affiliation(s)
- Joon Yul Choi
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Desk S51, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Zhong Irene Wang
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Desk S51, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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Carrette E, Stefan H. Evidence for the Role of Magnetic Source Imaging in the Presurgical Evaluation of Refractory Epilepsy Patients. Front Neurol 2019; 10:933. [PMID: 31551904 PMCID: PMC6746885 DOI: 10.3389/fneur.2019.00933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/12/2019] [Indexed: 12/03/2022] Open
Abstract
Magnetoencephalography (MEG) in the field of epilepsy has multiple advantages; just like electroencephalography (EEG), MEG is able to measure the epilepsy specific information (i.e., the brain activity reflecting seizures and/or interictal epileptiform discharges) directly, non-invasively and with a very high temporal resolution (millisecond-range). In addition MEG has a unique sensitivity for tangential sources, resulting in a full picture of the brain activity when combined with EEG. It accurately allows to perform source imaging of focal epileptic activity and functional cortex and shows a specific high sensitivity for a source in the neocortex. In this paper the current evidence and practice for using magnetic source imaging of focal interictal and ictal epileptic activity during the presurgical evaluation of drug resistant patients is being reviewed.
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Affiliation(s)
- Evelien Carrette
- Reference Centre for Refractory Epilepsy, Ghent University Hospital, Ghent, Belgium
| | - Hermann Stefan
- Department of Neurology-Biomagnetism, University Hospital Erlangen, Erlangen, Germany
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Steriade C, Martins W, Bulacio J, Morita-Sherman ME, Nair D, Gupta A, Bingaman W, Gonzalez-Martinez J, Najm I, Jehi L. Localization yield and seizure outcome in patients undergoing bilateral SEEG exploration. Epilepsia 2018; 60:107-120. [PMID: 30588603 DOI: 10.1111/epi.14624] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVE We aimed to determine the rates and predictors of resection and seizure freedom after bilateral stereo-electroencephalography (SEEG) implantation. METHODS We reviewed 184 patients who underwent bilateral SEEG implantation (2009-2015). Noninvasive and invasive evaluation findings were collected. Outcomes of interest included subsequent resection and seizure freedom. Statistical analyses employed multivariable logistic regression and proportional hazard modeling. Preoperative and postoperative seizure frequency, severity, and quality of life scales were also compared. RESULTS Following bilateral SEEG implantation, 106 of 184 patients (58%) underwent resection. Single seizure type (P = 0.007), a family history of epilepsy (P = 0.003), 10 or more seizures per month (P = 0.004), lower number of electrodes (P = 0.02), or sentinel electrode placement (P = 0.04) was predictive of undergoing a resection, as were lack of nonlocalized (P < 0.0001) or bilateral (P < 0.0001) ictal-onset zones on SEEG. Twenty-six of 81 patients (32% with follow-up greater than 1 year) remained seizure-free. Predictors of seizure freedom were single seizure type (P = 0.01), short epilepsy duration (P = 0.008), use of 2 or fewer antiepileptic drugs (AEDs) at the time of surgery (P = 0.0006), primary localization hypothesis involving the frontal lobe (P = 0.002), sentinel electrode placement only (P = 0.02), and lack of overlap between ictal-onset zone and eloquent cortex (P = 0.04), along with epilepsy substrate histopathology (P = 0.007). Complete resection of a suspected focal cortical dysplasia showed a trend to increased likelihood of seizure freedom (P = 0.09). The 44 of 55 patients (80%) who underwent resection and experienced seizure recurrence had >50% seizure reduction, as opposed to 26 of 45 patients (58%) who continued medical therapy alone (P = 0.003). Seventy-two percent of patients had a clinically meaningful quality of life improvement (>10% decrease in the Quality of Life in Epilepsy [QOLIE-10] score) at 1 year. SIGNIFICANCE A strong preimplantation hypothesis of a suspected unifocal epilepsy increases the odds of resection and seizure freedom. We discuss a tailored approach, taking into account localization hypothesis and suspected epilepsy etiology in guiding implantation and subsequent surgical strategy.
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Affiliation(s)
- Claude Steriade
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, Ohio
| | - William Martins
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, Ohio.,Porto Alegre Epilepsy Surgery Program, Neurology and Neurosurgery Services, Hospital São Lucas, Porto Alegre, Brazil
| | - Juan Bulacio
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, Ohio
| | | | - Dileep Nair
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Ajay Gupta
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, Ohio
| | | | | | - Imad Najm
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Lara Jehi
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, Ohio
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