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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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The Value of Source Localization for Clinical Magnetoencephalography: Beyond the Equivalent Current Dipole. J Clin Neurophysiol 2020; 37:537-544. [DOI: 10.1097/wnp.0000000000000487] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Pellegrino G, Hedrich T, Chowdhury R, Hall JA, Lina JM, Dubeau F, Kobayashi E, Grova C. Source localization of the seizure onset zone from ictal EEG/MEG data. Hum Brain Mapp 2016; 37:2528-46. [PMID: 27059157 DOI: 10.1002/hbm.23191] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 11/08/2022] Open
Abstract
INTRODUCTION Surgical treatment of drug-resistant epilepsy relies on the identification of the seizure onset zone (SOZ) and often requires intracranial EEG (iEEG). We have developed a new approach for non-invasive magnetic and electric source imaging of the SOZ (MSI-SOZ and ESI-SOZ) from ictal magnetoencephalography (MEG) and EEG recordings, using wavelet-based Maximum Entropy on the Mean (wMEM) method. We compared the performance of MSI-SOZ and ESI-SOZ with interictal spike source localization (MSI-spikes and ESI-spikes) and clinical localization of the SOZ (i.e., based on iEEG or lesion topography, denoted as clinical-SOZ). METHODS A total of 46 MEG or EEG seizures from 13 patients were analyzed. wMEM was applied around seizure onset, centered on the frequency band showing the strongest power change. Principal component analysis applied to spatiotemporal reconstructed wMEM sources (0.4-1 s around seizure onset) identified the main spatial pattern of ictal oscillations. Qualitative sublobar concordance and quantitative measures of distance and spatial overlaps were estimated to compare MSI/ESI-SOZ with MSI/ESI-Spikes and clinical-SOZ. RESULTS MSI/ESI-SOZ were concordant with clinical-SOZ in 81% of seizures (MSI 90%, ESI 64%). MSI-SOZ was more accurate and identified sources closer to the clinical-SOZ (P = 0.012) and to MSI-Spikes (P = 0.040) as compared with ESI-SOZ. MSI/ESI-SOZ and MSI/ESI-Spikes did not differ in terms of concordance and distance from the clinical-SOZ. CONCLUSIONS wMEM allows non-invasive localization of the SOZ from ictal MEG and EEG. MSI-SOZ performs better than ESI-SOZ. MSI/ESI-SOZ can provide important additional information to MSI/ESI-Spikes during presurgical evaluation. Hum Brain Mapp 37:2528-2546, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Giovanni Pellegrino
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada.,Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Tanguy Hedrich
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada
| | - Rasheda Chowdhury
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada
| | - Jeffery A Hall
- Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Jean-Marc Lina
- Département de Génie Electrique, École de Technologie Supérieure, Montreal, Québec, Canada.,Centre De Recherches En Mathématiques, Montreal, Québec, Canada.,Centre D'etudes Avancées En Médecine Du Sommeil, Centre De Recherche De L'hôpital Sacré-Coeur De Montréal, Montreal, Québec, Canada
| | - Francois Dubeau
- Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Eliane Kobayashi
- Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Christophe Grova
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada.,Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada.,Centre De Recherches En Mathématiques, Montreal, Québec, Canada.,Physics Department and PERFORM Centre, Concordia University, Montreal, Québec, Canada
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Ito T, Otsubo H, Shiraishi H, Yagyu K, Takahashi Y, Ueda Y, Takeuchi F, Takahashi K, Nakane S, Kohsaka S, Saitoh S. Advantageous information provided by magnetoencephalography for patients with neocortical epilepsy. Brain Dev 2015; 37:237-42. [PMID: 24819913 DOI: 10.1016/j.braindev.2014.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 04/04/2014] [Accepted: 04/08/2014] [Indexed: 11/29/2022]
Abstract
PURPOSE We evaluated whether magnetoencephalography (MEG), in addition to surgery, was valuable for the diagnosis and management of epileptic syndromes in patients with neocortical epilepsy (NE). METHODS We studied MEG in 73 patients (29 females; aged 1-26years; mean 10.3years) for the clinical diagnosis of epilepsy and for preoperative evaluation. MEG data were recorded by 204-channel whole head gradiometers with a 600Hz sampling rate. MEG spike sources were localized on magnetic resonance images (MRI) using a single dipole model to project equivalent current dipoles. RESULTS MEG localized an epileptic focus with single clustered dipoles in 24 (33%) of 73 NE patients: 16 (25%) of 64 symptomatic localization-related epilepsy (SLRE) patients and eight (89%) of nine idiopathic localization-related epilepsy (ILRE) patients. MEG provided advantageous information in 12 (50%) of 24 patients with clustered dipoles and confirmed the diagnosis in the remaining 12 (50%). Furthermore, the use of MEG resulted in changes to surgical treatments in nine (38%) patients and in medical management in eight (33%). MEG confirmed the diagnosis in eight (16%) of 49 patients with scattered dipoles. MRI identified a single lesion (28 patients, 38%), multiple lesions (5, 7%), and no lesion (40, 55%). MRI provided confirming information in 19 of 28 patients with a single lesion and 18 of them required surgical resections. MRI did not provide any supportive information in 54 (74%) patients with a single (9), multiple (5) and no lesion (40). CONCLUSION Our study shows that MEG provides fundamental information to aid the choice of diagnostic and therapeutic procedures including changes in medication in addition to surgical treatments for NE.
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Affiliation(s)
- Tomoshiro Ito
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Hiroshi Otsubo
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children and The University of Toronto, Toronto, Canada.
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Kazuyori Yagyu
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Yumi Takahashi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Yuki Ueda
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Fumiya Takeuchi
- Faculty of Health Sciences, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Kayoko Takahashi
- Division of Magnetoencephalography, Hokkaido University Hospital, Sapporo, Japan
| | - Shingo Nakane
- Division of Magnetoencephalography, Hokkaido University Hospital, Sapporo, Japan
| | - Shinobu Kohsaka
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Shinji Saitoh
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan; Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Kim H, Chung CK, Hwang H. Magnetoencephalography in pediatric epilepsy. KOREAN JOURNAL OF PEDIATRICS 2013; 56:431-8. [PMID: 24244211 PMCID: PMC3827491 DOI: 10.3345/kjp.2013.56.10.431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 06/04/2013] [Indexed: 11/27/2022]
Abstract
Magnetoencephalography (MEG) records the magnetic field generated by electrical activity of cortical neurons. The signal is not distorted or attenuated, and it is contactless recording that can be performed comfortably even for longer than an hour. It has excellent and decent temporal resolution, especially when it is combined with the patient's own brain magnetic resonance imaging (magnetic source imaging). Data of MEG and electroencephalography are not mutually exclusive and it is recorded simultaneously and interpreted together. MEG has been shown to be useful in detecting the irritative zone in both lesional and nonlesional epilepsy surgery. It has provided valuable and additive information regarding the lesion that should be resected in epilepsy surgery. Better outcomes in epilepsy surgery were related to the localization of the irritative zone with MEG. The value of MEG in epilepsy surgery is recruiting more patients to epilepsy surgery and providing critical information for surgical planning. MEG cortical mapping is helpful in younger pediatric patients, especially when the epileptogenic zone is close to the eloquent cortex. MEG is also used in both basic and clinical research of epilepsy other than surgery. MEG is a valuable diagnostic modality for diagnosis and treatment, as well as research in epilepsy.
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Affiliation(s)
- Hunmin Kim
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea
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Sun ZY, Wang JH, Sun JL, Wang TJ, Li L, Dong YH, Wu J, Cui WZ, Wu YJ, Lu PY. Magnetoencephalography assessment of evoked magnetic fields and cognitive function in subcortical ischemic vascular dementia patients. Neurosci Lett 2013; 532:17-22. [DOI: 10.1016/j.neulet.2012.10.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 10/13/2012] [Accepted: 10/17/2012] [Indexed: 10/27/2022]
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