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Park SC, Chung CK. Postoperative seizure outcome-guided machine learning for interictal electrocorticography in neocortical epilepsy. J Neurophysiol 2018. [PMID: 29513147 DOI: 10.1152/jn.00225.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The objective of this study was to introduce a new machine learning guided by outcome of resective epilepsy surgery defined as the presence/absence of seizures to improve data mining for interictal pathological activities in neocortical epilepsy. Electrocorticographies for 39 patients with medically intractable neocortical epilepsy were analyzed. We separately analyzed 38 frequencies from 0.9 to 800 Hz including both high-frequency activities and low-frequency activities to select bands related to seizure outcome. An automatic detector using amplitude-duration-number thresholds was used. Interictal electrocorticography data sets of 8 min for each patient were selected. In the first training data set of 20 patients, the automatic detector was optimized to best differentiate the seizure-free group from not-seizure-free-group based on ranks of resection percentages of activities detected using a genetic algorithm. The optimization was validated in a different data set of 19 patients. There were 16 (41%) seizure-free patients. The mean follow-up duration was 21 ± 11 mo (range, 13-44 mo). After validation, frequencies significantly related to seizure outcome were 5.8, 8.4-25, 30, 36, 52, and 75 among low-frequency activities and 108 and 800 Hz among high-frequency activities. Resection for 5.8, 8.4-25, 108, and 800 Hz activities consistently improved seizure outcome. Resection effects of 17-36, 52, and 75 Hz activities on seizure outcome were variable according to thresholds. We developed and validated an automated detector for monitoring interictal pathological and inhibitory/physiological activities in neocortical epilepsy using a data-driven approach through outcome-guided machine learning. NEW & NOTEWORTHY Outcome-guided machine learning based on seizure outcome was used to improve detections for interictal electrocorticographic low- and high-frequency activities. This method resulted in better separation of seizure outcome groups than others reported in the literature. The automatic detector can be trained without human intervention and no prior information. It is based only on objective seizure outcome data without relying on an expert's manual annotations. Using the method, we could find and characterize pathological and inhibitory activities.
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Affiliation(s)
- Seong-Cheol Park
- Department of Neurosurgery, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Republic of Korea.,Department of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Chun Kee Chung
- Department of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea.,Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea.,Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, Republic of Korea
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Davis KA, Devries SP, Krieger A, Mihaylova T, Minecan D, Litt B, Wagenaar JB, Stacey WC. The effect of increased intracranial EEG sampling rates in clinical practice. Clin Neurophysiol 2017; 129:360-367. [PMID: 29288992 DOI: 10.1016/j.clinph.2017.10.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/09/2017] [Accepted: 10/22/2017] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Recent research suggests that high frequency intracranial EEG (iEEG) may improve localization of epileptic networks. This study aims to determine whether recording macroelectrode iEEG with higher sampling rates improves seizure localization in clinical practice. METHODS 14 iEEG seizures from 10 patients recorded with >2000 Hz sampling rate were downsampled to four sampling rates: 100, 200, 500, 1000 Hz. In the 56 seizures, seizure onset time and location was marked by 5 independent, blinded EEG experts. RESULTS When reading iEEG under clinical conditions, there was no consistent difference in time or localization of seizure onset or number of electrodes involved in the seizure onset zone with sampling rates varying from 100 to 1000 Hz. Stratification of patients by outcome did not improve with higher sampling rate. CONCLUSION When utilizing standard clinical protocols, there was no benefit to acquiring iEEGs with sampling rate >100 Hz. Significant variability was noted in EEG marking both within and between individual expert EEG readers. SIGNIFICANCE Although commercial equipment is capable of sampling much faster than 100 Hz, tools allowing visualization of subtle high frequency activity such as HFOs will be required to improve patient care. Quantitative methods may decrease reader variability, and potentially improve patient outcomes.
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Affiliation(s)
| | - Seth P Devries
- Dept of Pediatric Neurology, Helen DeVos Children's Hospital, USA
| | - Abba Krieger
- Dept of Statistics, The Wharton School of the University of Pennsylvania, USA
| | | | | | - Brian Litt
- Department of Neurology, University of Pennsylvania, USA
| | - Joost B Wagenaar
- Department of Neurology, University of Pennsylvania, USA; Blackfynn, Inc, USA
| | - William C Stacey
- Dept of Neurology, University of Michigan, USA; Dept of Biomedical Engineering, University of Michigan, USA
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Wang MY, Wang J, Zhou J, Guan YG, Zhai F, Liu CQ, Xu FF, Han YX, Yan ZF, Luan GM. Identification of the epileptogenic zone of temporal lobe epilepsy from stereo-electroencephalography signals: A phase transfer entropy and graph theory approach. NEUROIMAGE-CLINICAL 2017; 16:184-195. [PMID: 28794979 PMCID: PMC5542420 DOI: 10.1016/j.nicl.2017.07.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 06/15/2017] [Accepted: 07/22/2017] [Indexed: 01/09/2023]
Abstract
The aim of this research is to apply an approach based on phase transfer entropy (PTE) and graph theory to study the interactions between the stereo-electroencephalography (SEEG) activities recorded in multilobar origin, in order to evaluate their ability to detect the epileptogenic zone (EZ) of temporal lobe epilepsies (TLE). Forty-three patients were included in this retrospective study. Five to sixteen (median = 12) multilead electrodes were implanted per patient, and, for each patient, a sub-set of between 10 and 32 (median = 22) bipolar derivations was selected for analysis. The leads were classified into the onset leads (OLs), the early propagation leads (EPLs), and the rest of the leads (RLs). The results showed that a significantly different dynamic trend of the out/in ratio (more obvious in the gamma band) distinguishes the OLs from RLs in the 23 patients who were seizure-free not only during the ictal event (significant elevation), but also during the inter-,pre-, late-ictal periods, and especially in the post-ictal (sharp decline) state. However, in the 20 patients who were not-seizure-free, the differences between the OLs and RLs during the post-ictal period were not found in any frequency band. The dynamic trend was used to predict surgical outcome, and the results showed that the sensitivity was 91% and the specificity was 70%. In brief, this study indicates that our approach may add new and valuable information, providing efficient quantitative measures useful for localizing the EZ.
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Affiliation(s)
- Meng-Yang Wang
- Epilepsy Center and Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Jing Wang
- Epilepsy Center and Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Jian Zhou
- Epilepsy Center and Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Yu-Guang Guan
- Epilepsy Center and Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Feng Zhai
- Epilepsy Center and Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Chang-Qing Liu
- Epilepsy Center and Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Fei-Fei Xu
- Epilepsy Center and Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Yi-Xian Han
- Epilepsy Center and Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Zhao-Fen Yan
- Epilepsy Center and Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
| | - Guo-Ming Luan
- Epilepsy Center and Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing Key Laboratory of Epilepsy, Beijing Institute for Brain Disorders, 50, Xiang-shan-yi-ke-song, Haidian District, Beijing 100093, China
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Jeong W, Kim JS, Chung CK. Usefulness of multiple frequency band source localizations in ictal MEG. Clin Neurophysiol 2015; 127:1049-1056. [PMID: 26235699 DOI: 10.1016/j.clinph.2015.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/24/2015] [Accepted: 07/15/2015] [Indexed: 12/13/2022]
Abstract
OBJECTIVE We evaluated the diagnostic value of multiple frequency band MEG source localization within a wide time window during the preictal period. METHODS Data for 13 epilepsy patients who showed an ictal event during MEG were analyzed. Several seconds of preictal data were localized in the theta, alpha, beta, and gamma bands by using wavelet transformation and the sLORETA algorithm. The same analysis was performed with narrow time and frequency band. Localization concordances to the surgically resected area were compared. RESULTS Source localization in the gamma band for a 10s window before ictal onset showed best concordance to the resection cavity. Eight of 13 patients showed sub-lobar concordance in the 10s gamma band localization, whereas 3 showed concordance in the narrow time and frequency analysis. Four of 7 patients with focal cortical dysplasia (FCD) achieved seizure-free outcome, and all 4 showed sub-lobar concordance. CONCLUSIONS A 10s time window gamma source localization method can be used to delineate the epileptogenic zone. SIGNIFICANCE The use of a long period during preictal gamma source localization has the potential to become a localizing biomarker of the epileptogenic zone in candidates for surgical intervention, especially in MRI-suspected FCD.
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Affiliation(s)
- Woorim Jeong
- Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea; Interdisciplinary Program in Neuroscience, Seoul National University College of Natural Science, Seoul, South Korea.
| | - June Sic Kim
- Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, South Korea.
| | - Chun Kee Chung
- Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea; Interdisciplinary Program in Neuroscience, Seoul National University College of Natural Science, Seoul, South Korea; Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, South Korea; Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, South Korea.
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