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Sun T, Wu S, Liu X, Tao JX, Wang Q. Impact of intracranial subclinical seizures on seizure outcomes after SLAH in patients with mesial temporal lobe epilepsy. Clin Neurophysiol 2024; 160:121-129. [PMID: 38422970 DOI: 10.1016/j.clinph.2024.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/31/2023] [Accepted: 02/11/2024] [Indexed: 03/02/2024]
Abstract
OBJECTIVE To investigate the association between subclinical seizures detected on intracranial electroencephalographic (i-SCSs)recordings and mesial temporal sclerosis (MTS), as well as their impact on surgical outcomes of stereotactic laser amygdalohippocampotomy (SLAH). METHODS A retrospective review was conducted on 27 patients with drug-resistant mesial temporal lobe epilepsy (MTLE) who underwent SLAH. The number of seizures detected on scalp EEG and iEEG was assessed. Patients were followed for a minimum of 3 years after SLAH. RESULTS Of the 1715 seizures recorded from mesial temporal regions, 1640 were identified as i-SCSs. Patients with MTS were associated with favorable short- and long-term surgical outcomes. Patients with MTS had a higher number of i-SCSs compared to patients without MTS. The numbers of i-SCSs were higher in patients with Engel I-II outcomes, but no significant statistical difference was found. However, it was observed that patients with MTS who achieved Engel I-II classification had higher numbers of i-SCSs than patients without MTS (P < 0.05). CONCLUSION Patients with MTS exhibited favorable short-term and long-term surgical outcome after SLAH. A higher number of i-SCSs was significantly associated with MTS in patients with MTLE. The number of i-SCSs tended to be higher in patients with Engel Ⅰ-Ⅱ surgical outcomes. SIGNIFICANCE The association between i-SCSs, MTS, and surgical outcomes in MTLE patients undergoing SLAH has significant implications for understanding the underlying mechanisms and identifying potential therapeutic targets to enhance surgical outcomes.
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Affiliation(s)
- Taixin Sun
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China; Department of Neurology, Beijing Electric Power Hospital, Capital Medical University, Beijing, PR China
| | - Shasha Wu
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | - Xi Liu
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, Hubei Province, PR China
| | - James X Tao
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | - Qun Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China.
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O’Leary J, McAndrew J, Shukralla A, Murphy K. Neuropsychiatric manifestations in a patient with prolonged COVID-19 encephalopathy: case report and literature review. Ir J Psychol Med 2023; 40:487-490. [PMID: 34544516 PMCID: PMC8523973 DOI: 10.1017/ipm.2021.67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 08/31/2021] [Accepted: 09/06/2021] [Indexed: 11/06/2022]
Abstract
While the respiratory complications of COVID-19 infection are now well known, psychiatric manifestations are an emerging issue. We report a case of prolonged encephalopathy secondary to COVID-19 which was associated with prominent neuropsychiatric features. The patient went on to develop sub-clinical seizures, a rare but recognised complication of SARS-CoV-2.
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Affiliation(s)
- J. O’Leary
- Department of Liaison Psychiatry, Beaumont Hospital, Dublin, Ireland
| | - J. McAndrew
- Department of Liaison Psychiatry, Beaumont Hospital, Dublin, Ireland
| | - A. Shukralla
- Department of Neurology, Beaumont Hospital, Dublin, Ireland
| | - K.C. Murphy
- Department of Liaison Psychiatry, Beaumont Hospital, Dublin, Ireland
- Department of Psychiatry, Royal College of Surgeons in Ireland, Dublin, Ireland
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Cui J, Balzekas I, Nurse E, Viana P, Gregg N, Karoly P, Stirling RE, Worrell G, Richardson MP, Freestone DR, Brinkmann BH. Perceived seizure risk in epilepsy: Chronic electronic surveys with and without concurrent electroencephalography. Epilepsia 2023; 64:2421-2433. [PMID: 37303239 PMCID: PMC10526687 DOI: 10.1111/epi.17678] [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: 01/22/2023] [Revised: 06/07/2023] [Accepted: 06/07/2023] [Indexed: 06/13/2023]
Abstract
OBJECTIVE Previous studies suggested that patients with epilepsy might be able to forecast their own seizures. This study aimed to assess the relationships between premonitory symptoms, perceived seizure risk, and future and recent self-reported and electroencephalographically (EEG)-confirmed seizures in ambulatory patients with epilepsy in their natural home environments. METHODS Long-term e-surveys were collected from patients with and without concurrent EEG recordings. Information obtained from the e-surveys included medication adherence, sleep quality, mood, stress, perceived seizure risk, and seizure occurrences preceding the survey. EEG seizures were identified. Univariate and multivariate generalized linear mixed-effect regression models were used to estimate odds ratios (ORs) for the assessment of the relationships. Results were compared with the seizure forecasting classifiers and device forecasting literature using a mathematical formula converting OR to equivalent area under the curve (AUC). RESULTS Fifty-four subjects returned 10 269 e-survey entries, with four subjects acquiring concurrent EEG recordings. Univariate analysis revealed that increased stress (OR = 2.01, 95% confidence interval [CI] = 1.12-3.61, AUC = .61, p = .02) was associated with increased relative odds of future self-reported seizures. Multivariate analysis showed that previous self-reported seizures (OR = 5.37, 95% CI = 3.53-8.16, AUC = .76, p < .001) were most strongly associated with future self-reported seizures, and high perceived seizure risk (OR = 3.34, 95% CI = 1.87-5.95, AUC = .69, p < .001) remained significant when prior self-reported seizures were added to the model. No correlation with medication adherence was found. No significant association was found between e-survey responses and subsequent EEG seizures. SIGNIFICANCE Our results suggest that patients may tend to self-forecast seizures that occur in sequential groupings and that low mood and increased stress may be the result of previous seizures rather than independent premonitory symptoms. Patients in the small cohort with concurrent EEG showed no ability to self-predict EEG seizures. The conversion from OR to AUC values facilitates direct comparison of performance between survey and device studies involving survey premonition and forecasting.
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Affiliation(s)
- Jie Cui
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Mayo College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, USA
| | - Irena Balzekas
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Ewan Nurse
- Seer Medical, Melbourne, Australia
- Department of Medicine, St. Vincent’s Hospital Melbourne, University of Melbourne, Melbourne, Australia
| | - Pedro Viana
- School of Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, UK
- Faculty of Medicine, University of Lisbon, Portugal
| | - Nicholas Gregg
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Philippa Karoly
- Department of Medicine, St. Vincent’s Hospital Melbourne, University of Melbourne, Melbourne, Australia
| | - Rachel E Stirling
- Seer Medical, Melbourne, Australia
- Department of Medicine, St. Vincent’s Hospital Melbourne, University of Melbourne, Melbourne, Australia
| | - Gregory Worrell
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Mark P Richardson
- School of Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, UK
| | | | - Benjamin H Brinkmann
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
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Ye H, He C, Hu W, Xiong K, Hu L, Chen C, Xu S, Xu C, Wang Y, Ding Y, Wu Y, Zhang K, Wang S, Wang S. Pre-ictal fluctuation of EEG functional connectivity discriminates seizure phenotypes in mesial temporal lobe epilepsy. Clin Neurophysiol 2023; 151:107-115. [PMID: 37245497 DOI: 10.1016/j.clinph.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 04/29/2023] [Accepted: 05/10/2023] [Indexed: 05/30/2023]
Abstract
OBJECTIVE We explored whether quantifiable differences between clinical seizures (CSs) and subclinical seizures (SCSs) occur in the pre-ictal state. METHODS We analyzed pre-ictal stereo-electroencephalography (SEEG) retrospectively across mesial temporal lobe epilepsy patients with recorded CSs and SCSs. Power spectral density and functional connectivity (FC) were quantified within and between the seizure onset zone (SOZ) and the early propagation zone (PZ), respectively. To evaluate the fluctuation of neural connectivity, FC variability was computed. Measures were further verified by a logistic regression model to evaluate their classification potentiality through the area under the receiver-operating-characteristics curve (AUC). RESULTS Fifty-four pre-ictal SEEG epochs (27 CSs and 27 SCSs) were selected among 14 patients. Within the SOZ, pre-ictal FC variability of CSs was larger than SCSs in 1-45 Hz during 30 seconds before seizure onset. Pre-ictal FC variability between the SOZ and PZ was larger in SCSs than CSs in 55-80 Hz within 1 minute before onset. Using these two variables, the logistic regression model achieved an AUC of 0.79 when classifying CSs and SCSs. CONCLUSIONS Pre-ictal FC variability within/between epileptic zones, not signal power or FC value, distinguished SCSs from CSs. SIGNIFICANCE Pre-ictal epileptic network stability possibly marks seizure phenotypes, contributing insights into ictogenesis and potentially helping seizure prediction.
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Affiliation(s)
- Hongyi Ye
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Chenmin He
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Wenhan Hu
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kai Xiong
- State Key Lab of CAD&CG, Zhejiang University, Hangzhou, China
| | - Lingli Hu
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Cong Chen
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Sha Xu
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Cenglin Xu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, Basic Medical College, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yi Wang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, Basic Medical College, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yao Ding
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yingcai Wu
- State Key Lab of CAD&CG, Zhejiang University, Hangzhou, China
| | - Kai Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shan Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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Erkent I, Arslan GA, Saygi S, Irsel Tezer F. Subclinical seizures: The demographic data and scalp video-EEG findings, concordance with the epilepsy type and prognosis. Epilepsy Res 2023; 192:107142. [PMID: 37075526 DOI: 10.1016/j.eplepsyres.2023.107142] [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: 02/26/2023] [Revised: 04/01/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
BACKGROUND Subclinical seizures(SCSs) are overlooked in clinical practice. This study aims to investigate clinical, electrophysiological features of SCSs detected during video-electroencephalography(EEG) monitorization(VEM), concordance of the epilepsy type and SCSs, and predictors of the concordance. METHODS The data of drug-resistant epilepsy patients who had undergone video-EEG between 2010 and 2020 were investigated. Ictal activities showing temporospatial evolution lasted ≥ 10 s, without any behavioural changes were considered SCSs. Findings were re-evaluated for ictal localization, lateralization, ictal discharge type, vigilance status, and duration of SCSs to the accompaniment of clinical findings. Additionally, the concordance of epilepsy type and SCSs were analyzed. RESULTS Fifty-five SCSs were obtained in 24 of 804 patients (2,9 %) who were followed in the VEM unit; the epilepsy type of the patients was temporal in 26 and extratemporal lobe epilepsy in 29 SCSs. Among 55 SCSs recordings, 30 originated from the temporal lobe and 24 from the extratemporal lobe, and seizure localization could not be determined in one. The patients were younger, age at seizure onset was earlier, habitual seizures were more frequent, multiple anti-seizure drug use was higher, seizures more frequently occurred during sleep, cranial MR tended to be abnormal, patients were more likely to have a history of perinatal injury/head trauma, and the concordance of discharge patterns was lower in extratemporal SCSs.The concordance of epilepsy type with localization and lateralization of SCSs was not statistically significant. CONCLUSIONS SCSs originating from the temporal and extratemporal lobes might show similar characteristics with the epilepsy type, and SCSs might have clinical importance apart from epilepsy surgery.
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Affiliation(s)
- Irem Erkent
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| | - Gokce Ayhan Arslan
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Serap Saygi
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - F Irsel Tezer
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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Cui J, Balzekas I, Nurse E, Viana P, Gregg N, Karoly P, Worrell G, Richardson MP, Freestone DR, Brinkmann BH. Perceived seizure risk in epilepsy â€" Chronic electronic surveys with and without concurrent EEG. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.23.23287561. [PMID: 37034596 PMCID: PMC10081426 DOI: 10.1101/2023.03.23.23287561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Objective Previous studies suggested that patients with epilepsy might be able to fore-cast their own seizures. We sought to assess the relationships of premonitory symptoms and perceived seizure risk with future and recent self-reported and EEG-confirmed seizures in the subjects living with epilepsy in their natural home environments. Methods We collected long-term e-surveys from ambulatory patients with and without concurrent EEG recordings. Information obtained from the e-surveys included medication compliance, sleep quality, mood, stress, perceived seizure risk and seizure occurrences preceding the survey. EEG seizures were identified. Univariate and multivariate generalized linear mixed-effect regression models were used to estimate odds ratios (ORs) for the assessment of the relationships. Results were compared with device seizure forecasting literature using a mathematical formula converting OR to equivalent area under the curve (AUC). Results Sixty-nine subjects returned 12,590 e-survey entries, with four subjects acquiring concurrent EEG recordings. Univariate analysis revealed increased stress (OR = 2.52, 95% CI = [1.52, 4.14], p < 0.001) and decreased mood (0.32, [0.13, 0.82], 0.02) were associated with increased relative odds of future self-reported seizures. On multivariate analysis, previous self-reported seizures (4.24, [2.69, 6.68], < 0.001) were most strongly associated with future self-reported seizures, and high perceived seizure risk (3.30, [1.97, 5.52], < 0.001) remained significant when prior self-reported seizures were added to the model. No significant association was found between e-survey responses and subsequent EEG seizures. Significance It appears that patients may tend to self-forecast seizures that occur in sequential groupings. Our results suggest that low mood and increased stress may be the result of previous seizures rather than independent premonitory symptoms. Patients in the small cohort with concurrent EEG showed no ability to self-predict EEG seizures. The conversion from OR to AUC values facilitates direct comparison of performance between survey and device studies involving survey premonition and forecasting. Key points Long-term e-surveys data and concurrent EEG signals were collected across three study sites to assess the ability of the patients to self-forecast their seizures.Patients may tend to self-forecast self-reported seizures that occur in sequential groupings.Factors, such as mood and stress, may not be independent premonitory symptoms but may be the consequence of recent seizures.No ability to self-forecast EEG confirmed seizures was observed in a small cohort with concurrent EEG validation.A mathematic relation between OR and AUC provides a means to compare forecasting performance between survey and device studies.
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Affiliation(s)
- Jie Cui
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
- Mayo College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, USA
| | - Irena Balzekas
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Ewan Nurse
- Seer Medical, Melbourne, Australia
- Department of Medicine, St. Vincent’s Hospital Melbourne, University of Melbourne, Melbourne, Australia
| | - Pedro Viana
- School of Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, UK
- Faculty of Medicine, University of Lisbon, Portugal
| | - Nicholas Gregg
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Philippa Karoly
- Department of Medicine, St. Vincent’s Hospital Melbourne, University of Melbourne, Melbourne, Australia
| | - Gregory Worrell
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Mark P Richardson
- School of Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, UK
| | | | - Benjamin H. Brinkmann
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
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Cox BC, Khattak JF, Starnes K, Brinkmann BH, Tatum WO, Noe KH, Van Gompel JJ, Miller KJ, Marsh WR, Grewal SS, Zimmerman RS, So EL, Wong-Kisiel LC, Burkholder DB. Subclinical seizures on stereotactic EEG: characteristics and prognostic value. Seizure 2022; 101:96-102. [DOI: 10.1016/j.seizure.2022.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/14/2022] [Accepted: 07/24/2022] [Indexed: 12/01/2022] Open
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He C, Chen C, Yang Y, Hu L, Jin B, Ming W, Wang Z, Ding Y, Ding M, Wang S, Wang S. Clinical Characteristics and Prognostic Significance of Subclinical Seizures in Focal Epilepsy: A Retrospective Study. Neurol Ther 2022; 11:763-779. [PMID: 35378679 PMCID: PMC9095772 DOI: 10.1007/s40120-022-00342-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/09/2022] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION The aim was to evaluate the clinical characteristics and prognostic significance of subclinical seizures (SCSs) on scalp video-electroencephalogram (VEEG) monitoring with or without intracranial electroencephalogram (IEEG) monitoring in patients who had epilepsy surgery. METHODS We reviewed 286 epileptic patients who underwent subsequent epilepsy surgery during scalp-VEEG evaluation with or without IEEG monitoring between 2013 and 2020, with a minimum follow-up of 1 year. The prevalence and clinical characteristics of SCSs, as well as their prognostic significance, were analyzed. RESULTS A total of 286 patients were enrolled for analysis, and 80 patients had IEEG implanted. SCSs were recorded in 9.79% of the patients based on VEEG and 50% based on IEEG. In the VEEG group (n = 286), younger seizure onset (P = 0.004) was associated with the presence of s-SCSs (SCSs detected on scalp VEEG). In the IEEG group (n = 80), temporal lobe epilepsy (P = 0.015) was associated with the presence of i-SCSs (SCSs detected on IEEG). Of 286 patients, 208 (72.73%) were seizure-free in the VEEG group, and 56 0f 80 patients (70%) were seizure-free in the IEEG group through the last follow-up. In the VEEG group, the presence of s-SCSs did not affect seizure outcome; predictors of seizure recurrence were longer epilepsy duration (P = 0.003, OR 1.003, 95% CI 1.001-1.005), history of focal to bilateral tonic-clonic seizure (P = 0.027, OR 1.665, 95% CI 1.060-2.613), nonspecific pathology (P = 0.018, OR 2.184, 95% CI 1.145-4.163), and incomplete resection (P = 0.004, OR 2.705, 95% CI 1.372-5.332). In the IEEG group, i-SCSs were significantly associated with seizure outcome (P = 0.028, OR 0.371, 95% CI 0.153-0.898). CONCLUSION The rate of SCSs captured on IEEG monitoring was higher than that on VEEG monitoring during presurgical evaluation. SCSs detected on VEEG monitoring were associated with younger seizure onset. SCSs detected on IEEG monitoring were associated with temporal lobe epilepsy and also predicted surgical outcomes in focal epilepsy.
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Affiliation(s)
- Chenmin He
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Cong Chen
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Yuyu Yang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Lingli Hu
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Bo Jin
- Department of Neurology, Zhejiang Provincial People's Hospital, Hangzhou, China
| | - Wenjie Ming
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Zhongjin Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Yao Ding
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Meiping Ding
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Shuang Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
| | - Shan Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
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Tsuboyama M, Harini C, Liu S, Zhang B, Bolton J. Subclinical seizures detected on intracranial EEG: Patient characteristics and impact on surgical outcome in a single pediatric epilepsy surgery center. Epilepsy Behav 2021; 121:108040. [PMID: 34058491 DOI: 10.1016/j.yebeh.2021.108040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/02/2021] [Accepted: 05/02/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Subclinical seizures (SCS) are often captured during intracranial EEG monitoring of pediatric patients with refractory focal epilepsy. However, their clinical significance remains uncertain. We aimed to characterize features associated with SCS and whether their presence impacts epilepsy outcomes post-surgically. METHODS A single center retrospective chart review of patients with refractory focal epilepsy who underwent intracranial EEG monitoring at Boston Children's Hospital between 2004 and 2014 was conducted. Patient and seizure characteristics as well as post-operative outcome data were collected. RESULTS Of the 104 patients included in the study, SCS were recorded in 66 (63%). Fifty-eight had electroclinical seizures (ECS) and SCS (ECS + SCS), and eight patients only had SCS. There were no significant patient characteristics associated with the presence of SCS. One hundred one of the 104 patients (97%) underwent surgical resection after the intracranial EEG monitoring, 53 of which had Engel 1 outcomes (52%). Incomplete resection (OR 0.15, 95% confidence interval (CI) [0.06, 0.40], p < 0.001) or presence of temporal plus epilepsy (OR 0.23, 95% CI [0.06, 0.80], p = 0.04) was associated with poor Engel outcomes (Engel 2-4). Presence of SCS was not associated with epilepsy surgical outcomes (p = 0.99). SIGNIFICANCE Nearly 2/3 of patients in our study had SCS captured on intracranial EEG monitoring, and arose in overlapping regions with the ictal onset zone of ECS. Completeness of resection remains the most important predictor of seizure outcome, regardless of the presence of SCS. In the absence of ECS during intracranial EEG monitoring, SCS onset zones may provide useful localization information to guide surgical resection plans. This is the largest cohort reported in the literature describing characteristics associated with the presence of SCS and the impact of SCS on pediatric epilepsy surgery outcomes.
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Affiliation(s)
- Melissa Tsuboyama
- Division of Epilepsy and Neurophysiology, Boston Children's Hospital, Boston, MA, United States.
| | - Chellamani Harini
- Division of Epilepsy and Neurophysiology, Boston Children's Hospital, Boston, MA, United States
| | - Shanshan Liu
- Biostatistics and Research Design Center, Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, United States
| | - Bo Zhang
- Department of Neurology, Boston Children's Hospital, Boston, MA, United States; Biostatistics and Research Design Center, Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, United States
| | - Jeffrey Bolton
- Division of Epilepsy and Neurophysiology, Boston Children's Hospital, Boston, MA, United States
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Balzekas I, Sladky V, Nejedly P, Brinkmann BH, Crepeau D, Mivalt F, Gregg NM, Pal Attia T, Marks VS, Wheeler L, Riccelli TE, Staab JP, Lundstrom BN, Miller KJ, Van Gompel J, Kremen V, Croarkin PE, Worrell GA. Invasive Electrophysiology for Circuit Discovery and Study of Comorbid Psychiatric Disorders in Patients With Epilepsy: Challenges, Opportunities, and Novel Technologies. Front Hum Neurosci 2021; 15:702605. [PMID: 34381344 PMCID: PMC8349989 DOI: 10.3389/fnhum.2021.702605] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/29/2021] [Indexed: 01/10/2023] Open
Abstract
Intracranial electroencephalographic (iEEG) recordings from patients with epilepsy provide distinct opportunities and novel data for the study of co-occurring psychiatric disorders. Comorbid psychiatric disorders are very common in drug-resistant epilepsy and their added complexity warrants careful consideration. In this review, we first discuss psychiatric comorbidities and symptoms in patients with epilepsy. We describe how epilepsy can potentially impact patient presentation and how these factors can be addressed in the experimental designs of studies focused on the electrophysiologic correlates of mood. Second, we review emerging technologies to integrate long-term iEEG recording with dense behavioral tracking in naturalistic environments. Third, we explore questions on how best to address the intersection between epilepsy and psychiatric comorbidities. Advances in ambulatory iEEG and long-term behavioral monitoring technologies will be instrumental in studying the intersection of seizures, epilepsy, psychiatric comorbidities, and their underlying circuitry.
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Affiliation(s)
- Irena Balzekas
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States
- Mayo Clinic Alix School of Medicine, Rochester, MN, United States
- Mayo Clinic Medical Scientist Training Program, Rochester, MN, United States
| | - Vladimir Sladky
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czechia
| | - Petr Nejedly
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- The Czech Academy of Sciences, Institute of Scientific Instruments, Brno, Czechia
| | - Benjamin H. Brinkmann
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Daniel Crepeau
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Filip Mivalt
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Faculty of Electrical Engineering and Communication, Department of Biomedical Engineering, Brno University of Technology, Brno, Czechia
| | - Nicholas M. Gregg
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Tal Pal Attia
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Victoria S. Marks
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States
| | - Lydia Wheeler
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Biomedical Engineering and Physiology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States
- Mayo Clinic Alix School of Medicine, Rochester, MN, United States
| | - Tori E. Riccelli
- Mayo Clinic Alix School of Medicine, Rochester, MN, United States
| | - Jeffrey P. Staab
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
- Department of Otorhinolaryngology, Mayo Clinic, Rochester, MN, United States
| | - Brian Nils Lundstrom
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Kai J. Miller
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Department of Neurosurgery, Mayo Clinic, Rochester, MN, United States
| | - Jamie Van Gompel
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Department of Neurosurgery, Mayo Clinic, Rochester, MN, United States
| | - Vaclav Kremen
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Prague, Czechia
| | - Paul E. Croarkin
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
| | - Gregory A. Worrell
- Bioelectronics, Neurophysiology, and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, United States
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11
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Wang GH, Chou P, Hsueh SW, Yang YC, Kuo CC. Glutamate transmission rather than cellular pacemaking propels excitatory-inhibitory resonance for ictogenesis in amygdala. Neurobiol Dis 2020; 148:105188. [PMID: 33221531 DOI: 10.1016/j.nbd.2020.105188] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 10/20/2020] [Accepted: 11/17/2020] [Indexed: 12/16/2022] Open
Abstract
Epileptic seizures are automatic, excessive, and synchronized neuronal activities originating from many brain regions especially the amygdala, the allocortices and neocortices. This may reflect a shared principle for network organization and signaling in these telencephalic structures. In theory, the automaticity of epileptic discharges may stem from spontaneously active "oscillator" neurons equipped with intrinsic pacemaking conductances, or from a group of synaptically-connected collaborating "resonator" neurons. In the basolateral amygdalar (BLA) network of pyramidal-inhibitory (PN-IN) neuronal resonators, we demonstrated that rhythmogenic currents are provided by glutamatergic rather than the classic intrinsic or cellular pacemaking conductances (namely the h currents). The excitatory output of glutamatergic neurons such as PNs presumably propels a novel network-based "relay burst mode" of discharges especially in INs, which precondition PNs into a state prone to burst discharges and thus further glutamate release. Also, selective activation of unilateral PNs, but never INs, readily drives bilateral BLA networks into reverberating discharges which are fully synchronized with the behavioral manifestations of seizures (e.g. muscle contractions). Seizures originating in BLA and/or the other structures with similar PN-IN networks thus could be viewed as glutamate-triggered erroneous network oscillations that are normally responsible for information relay.
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Affiliation(s)
- Guan-Hsun Wang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; School of Medicine, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Department of Medical Education, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan
| | - Ping Chou
- Department of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shu-Wei Hsueh
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Ya-Chin Yang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan.
| | - Chung-Chin Kuo
- Department of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.
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12
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Kokkinos V, Sisterson ND, Wozny TA, Richardson RM. Association of Closed-Loop Brain Stimulation Neurophysiological Features With Seizure Control Among Patients With Focal Epilepsy. JAMA Neurol 2020; 76:800-808. [PMID: 30985902 DOI: 10.1001/jamaneurol.2019.0658] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance A bidirectional brain-computer interface that performs neurostimulation has been shown to improve seizure control in patients with refractory epilepsy, but the therapeutic mechanism is unknown. Objective To investigate whether electrographic effects of responsive neurostimulation (RNS), identified in electrocorticographic (ECOG) recordings from the device, are associated with patient outcomes. Design, Setting, and Participants Retrospective review of ECOG recordings and accompanying clinical meta-data from 11 consecutive patients with focal epilepsy who were implanted with a neurostimulation system between January 28, 2015, and June 6, 2017, with 22 to 112 weeks of follow-up. Recorded ECOG data were obtained from the manufacturer; additional system-generated meta-data, including recording and detection settings, were collected directly from the manufacturer's management system using an in-house, custom-built platform. Electrographic seizure patterns were identified in RNS recordings and evaluated in the time-frequency domain, which was locked to the onset of the seizure pattern. Main Outcomes and Measures Patterns of electrophysiological modulation were identified and then classified according to their latency of onset in relation to triggered stimulation events. Seizure control after RNS implantation was assessed by 3 main variables: mean frequency of seizure occurrence, estimated mean severity of seizures, and mean duration of seizures. Overall seizure outcomes were evaluated by the extended Personal Impact of Epilepsy Scale questionnaires, a patient-reported outcome measure of 3 domains (seizure characteristics, medication adverse effects, and quality of life), with a range of possible scores from 0 to 300 in which lower scores indicate worse status, and the Engel scale, which comprises 4 classes (I-IV) in which lower numbers indicate greater improvement. Results Electrocorticographic data from 11 patients (8 female; mean [range] age, 35 [19-65] years; mean [range] duration of epilepsy, 19 [5-37] years) were analyzed. Two main categories of electrophysiological signatures of stimulation-induced modulation of the seizure network were discovered: direct and indirect effects. Direct effects included ictal inhibition and early frequency modulation but were not associated with improved clinical outcomes (odds ratio [OR], 0.67; 95% CI, 0.06-7.35; P > .99). Only indirect effects-those occurring remote from triggered stimulation-were associated with improved clinical outcomes (OR, infinity; 95% CI, -infinity to infinity; P = .02). These indirect effects included spontaneous ictal inhibition, frequency modulation, fragmentation, and ictal duration modulation. Conclusions and Relevance These findings suggest that RNS effectiveness may be explained by long-term, stimulation-induced modulation of seizure network activity rather than by direct effects on each detected seizure.
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Affiliation(s)
- Vasileios Kokkinos
- Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, Pennsylvania
| | - Nathaniel D Sisterson
- Medical student, Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Thomas A Wozny
- Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - R Mark Richardson
- Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, Pennsylvania.,University of Pittsburgh Brain Institute, Pittsburgh, Pennsylvania
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13
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King-Stephens D. The Value of Localizing Subclinical Seizures. Epilepsy Curr 2020; 20:147-148. [PMID: 32550835 PMCID: PMC7281903 DOI: 10.1177/1535759720917401] [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: 11/15/2022] Open
Abstract
[Box: see text]
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14
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Tanaka H, Gotman J, Khoo HM, Olivier A, Hall J, Dubeau F. Neurophysiological seizure-onset predictors of epilepsy surgery outcome: a multivariable analysis. J Neurosurg 2019; 133:1863-1872. [PMID: 31783358 DOI: 10.3171/2019.9.jns19527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 09/18/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The authors sought to determine which neurophysiological seizure-onset features seen during scalp electroencephalography (EEG) and intracerebral EEG (iEEG) monitoring are predictors of postoperative outcome in a large series of patients with drug-resistant focal epilepsy who underwent resective surgery. METHODS The authors retrospectively analyzed the records of 75 consecutive patients with focal epilepsy, who first underwent scalp EEG and then iEEG (stereo-EEG) for presurgical assessment and who went on to undergo resective surgery between 2004 and 2015. To determine the independent prognostic factors from the neurophysiological scalp EEG and iEEG seizure-onset information, univariate and standard multivariable logistic regression analyses were used. Since scalp EEG and iEEG data were recorded at different times, the authors matched scalp seizures with intracerebral seizures for each patient using strict criteria. RESULTS A total of 3057 seizures were assessed. Forty-eight percent (36/75) of patients had a favorable outcome (Engel class I-II) after a minimum follow-up of at least 1 year. According to univariate analysis, a localized scalp EEG seizure onset (p < 0.001), a multilobar intracerebral seizure-onset zone (SOZ) (p < 0.001), and an extended SOZ (p = 0.001) were significantly associated with surgical outcome. According to multivariable analysis, the following two independent factors were found: 1) the ability of scalp EEG to localize the seizure onset was a predictor of a favorable postoperative outcome (OR 6.073, 95% CI 2.011-18.339, p = 0.001), and 2) a multilobar SOZ was a predictor of an unfavorable outcome (OR 0.076, 95% CI 0.009-0.663, p = 0.020). CONCLUSIONS The study findings show that localization at scalp seizure onset and a multilobar SOZ were strong predictors of surgical outcome. These predictors can help to select the better candidates for resective surgery.
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Affiliation(s)
- Hideaki Tanaka
- 1Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
- 2Department of Neurosurgery, Fukuoka University Hospital
- 3Fukuoka Sanno Hospital, Epilepsy and Sleep Center, Fukuoka; and
| | - Jean Gotman
- 1Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Hui Ming Khoo
- 1Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
- 4Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - André Olivier
- 1Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Jeffery Hall
- 1Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - François Dubeau
- 1Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
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15
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Wang S, Wang ZI, Tang Y, Alexopoulos AV, Chen C, Katagiri M, Aung T, Najm IM, Ding M, Wang S, Chauvel P. Localization value of subclinical seizures on scalp video‐EEG in epilepsy presurgical evaluation. Epilepsia 2019; 60:2477-2485. [PMID: 31755095 DOI: 10.1111/epi.16383] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Shan Wang
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Z. Irene Wang
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Yingying Tang
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
- Department of Neurology West China Hospital Sichuan University Chengdu China
| | | | - Cong Chen
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
| | - Masaya Katagiri
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Thandar Aung
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Imad M. Najm
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Meiping Ding
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
| | - Shuang Wang
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
| | - Patrick Chauvel
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
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16
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de Groen AEC, Bolton J, Bergin AM, Sahin M, Peters JM. The Evolution of Subclinical Seizures in Children With Tuberous Sclerosis Complex. J Child Neurol 2019; 34:770-777. [PMID: 31290714 DOI: 10.1177/0883073819860640] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Subclinical seizures are electrographic seizures that present without subjective or objective clinical symptoms. In tuberous sclerosis complex, it is not known whether subclinical seizures occur alone, forewarn, or coexist with clinical seizures. To address this knowledge gap, we studied the prevalence and evolution of subclinical seizures in tuberous sclerosis complex. METHODS We retrospectively reviewed electroencephalography (EEG) data from our tuberous sclerosis complex clinic with subclinical seizures and clinical seizures in a blinded fashion. Based on EEG location and ictal pattern, subclinical seizures were classified as having a clinical counterpart from the same epileptogenic region (match) or not (no match). RESULTS Of 208 children with tuberous sclerosis complex, 138 had epilepsy and available EEG data. Subclinical seizures were detected in 26 of 138 (19%) children. Twenty-four children had both subclinical seizures and clinical seizures captured on EEG. In 13 of 24, subclinical seizures were detected as a novel, not previously recorded seizure type. In these children, subclinical seizures preceded matching clinical seizures in 4 (31%) within a median time of 4.5 months (range 2-14), whereas 9 (69%) never had any matching clinical seizure. In 11 of 24 children, subclinical seizures were not novel and could be matched to a previously recorded clinical seizure. Matching seizure types were focal (n = 10, 67%), tonic (n = 2), epileptic spasms (n = 2), and status epilepticus (n = 1). CONCLUSIONS Subclinical seizures occur in one-fifth of children with tuberous sclerosis complex and epilepsy, and match with clinical seizures in a small majority. In a third of patients presenting with a novel subclinical seizure, matching clinical seizures follow.
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Affiliation(s)
- Anne-Elise C de Groen
- 1 Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jeffrey Bolton
- 1 Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ann Marie Bergin
- 1 Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Mustafa Sahin
- 2 Department of Neurology, Translational Neuroscience Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jurriaan M Peters
- 1 Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
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17
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Abstract
BACKGROUND This is an updated version of the original Cochrane review, published in 2015.Focal epilepsies are caused by a malfunction of nerve cells localised in one part of one cerebral hemisphere. In studies, estimates of the number of individuals with focal epilepsy who do not become seizure-free despite optimal drug therapy vary between at least 20% and up to 70%. If the epileptogenic zone can be located, surgical resection offers the chance of a cure with a corresponding increase in quality of life. OBJECTIVES The primary objective is to assess the overall outcome of epilepsy surgery according to evidence from randomised controlled trials.Secondary objectives are to assess the overall outcome of epilepsy surgery according to non-randomised evidence, and to identify the factors that correlate with remission of seizures postoperatively. SEARCH METHODS For the latest update, we searched the following databases on 11 March 2019: Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid, 1946 to March 08, 2019), ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). SELECTION CRITERIA Eligible studies were randomised controlled trials (RCTs) that included at least 30 participants in a well-defined population (age, sex, seizure type/frequency, duration of epilepsy, aetiology, magnetic resonance imaging (MRI) diagnosis, surgical findings), with an MRI performed in at least 90% of cases and an expected duration of follow-up of at least one year, and reporting an outcome related to postoperative seizure control. Cohort studies or case series were included in the previous version of this review. DATA COLLECTION AND ANALYSIS Three groups of two review authors independently screened all references for eligibility, assessed study quality and risk of bias, and extracted data. Outcomes were proportions of participants achieving a good outcome according to the presence or absence of each prognostic factor of interest. We intended to combine data with risk ratios (RRs) and 95% confidence intervals (95% CIs). MAIN RESULTS We identified 182 studies with a total of 16,855 included participants investigating outcomes of surgery for epilepsy. Nine studies were RCTs (including two that randomised participants to surgery or medical treatment (99 participants included in the two trials received medical treatment)). Risk of bias in these RCTs was unclear or high. Most of the remaining 173 non-randomised studies followed a retrospective design. We assessed study quality using the Effective Public Health Practice Project (EPHPP) tool and determined that most studies provided moderate or weak evidence. For 29 studies reporting multivariate analyses, we used the Quality in Prognostic Studies (QUIPS) tool and determined that very few studies were at low risk of bias across domains.In terms of freedom from seizures, two RCTs found surgery (n = 97) to be superior to medical treatment (n = 99); four found no statistically significant differences between anterior temporal lobectomy (ATL) with or without corpus callosotomy (n = 60), between subtemporal or transsylvian approach to selective amygdalohippocampectomy (SAH) (n = 47); between ATL, SAH and parahippocampectomy (n = 43) or between 2.5 cm and 3.5 cm ATL resection (n = 207). One RCT found total hippocampectomy to be superior to partial hippocampectomy (n = 70) and one found ATL to be superior to stereotactic radiosurgery (n = 58); and another provided data to show that for Lennox-Gastaut syndrome, no significant differences in seizure outcomes were evident between those treated with resection of the epileptogenic zone and those treated with resection of the epileptogenic zone plus corpus callosotomy (n = 43). We judged evidence from the nine RCTs to be of moderate to very low quality due to lack of information reported about the randomised trial design and the restricted study populations.Of the 16,756 participants included in this review who underwent a surgical procedure, 10,696 (64%) achieved a good outcome from surgery; this ranged across studies from 13.5% to 92.5%. Overall, we found the quality of data in relation to recording of adverse events to be very poor.In total, 120 studies examined between one and eight prognostic factors in univariate analysis. We found the following prognostic factors to be associated with a better post-surgical seizure outcome: abnormal pre-operative MRI, no use of intracranial monitoring, complete surgical resection, presence of mesial temporal sclerosis, concordance of pre-operative MRI and electroencephalography, history of febrile seizures, absence of focal cortical dysplasia/malformation of cortical development, presence of tumour, right-sided resection, and presence of unilateral interictal spikes. We found no evidence that history of head injury, presence of encephalomalacia, presence of vascular malformation, and presence of postoperative discharges were prognostic factors of outcome.Twenty-nine studies reported multi-variable models of prognostic factors, and showed that the direction of association of factors with outcomes was generally the same as that found in univariate analyses.We observed variability in many of our analyses, likely due to small study sizes with unbalanced group sizes and variation in the definition of seizure outcome, the definition of prognostic factors, and the influence of the site of surgery AUTHORS' CONCLUSIONS: Study design issues and limited information presented in the included studies mean that our results provide limited evidence to aid patient selection for surgery and prediction of likely surgical outcomes. Future research should be of high quality, follow a prospective design, be appropriately powered, and focus on specific issues related to diagnostic tools, the site-specific surgical approach, and other issues such as extent of resection. Researchers should investigate prognostic factors related to the outcome of surgery via multi-variable statistical regression modelling, where variables are selected for modelling according to clinical relevance, and all numerical results of the prognostic models are fully reported. Journal editors should not accept papers for which study authors did not record adverse events from a medical intervention. Researchers have achieved improvements in cancer care over the past three to four decades by answering well-defined questions through the conduct of focused RCTs in a step-wise fashion. The same approach to surgery for epilepsy is required.
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Affiliation(s)
- Siobhan West
- Royal Manchester Children's HospitalDepartment of Paediatric NeurologyHathersage RoadManchesterUKM13 0JH
| | - Sarah J Nevitt
- University of LiverpoolDepartment of BiostatisticsBlock F, Waterhouse Building1‐5 Brownlow HillLiverpoolUKL69 3GL
| | - Jennifer Cotton
- The Clatterbridge Cancer Centre NHS Foundation TrustWirralUK
| | - Sacha Gandhi
- NHS Ayrshire and ArranDepartment of General SurgeryAyrUKKA6 6DX
| | - Jennifer Weston
- Institute of Translational Medicine, University of LiverpoolDepartment of Molecular and Clinical PharmacologyClinical Sciences Centre for Research and Education, Lower LaneFazakerleyLiverpoolMerseysideUKL9 7LJ
| | - Ajay Sudan
- Royal Manchester Children's HospitalDepartment of Paediatric NeurologyHathersage RoadManchesterUKM13 0JH
| | - Roberto Ramirez
- Royal Manchester Children's HospitalHospital RoadPendleburyManchesterUKM27 4HA
| | - Richard Newton
- Royal Manchester Children's HospitalDepartment of Paediatric NeurologyHathersage RoadManchesterUKM13 0JH
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18
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Abstract
After more than 85 years of development and use in clinical practice, the electroencephalogram (EEG) remains a dependable, inexpensive, and useful diagnostic tool for the investigation of the electrophysiologic activity of the brain. The advent of digital technology has led to greater sophistication and multiple software applications to extend the utility of EEG beyond the confines of the laboratory. Despite the discovery of new waveforms, basic neurophysiologic principles remain essential to the clinical care of patients. Patterns in the interictal EEG make it possible to clarify the differential diagnosis of paroxysmal neurological events, classify seizure type and epilepsy syndromes, and characterize and quantify seizures when ictal recordings are obtained. EEG can also demonstrate cerebral dysfunction when structural imaging is normal to detect focal or lateralized abnormalities in patients with encephalopathy. High-density EEG with electrical source imaging has improved localization in candidates for epilepsy surgery. Quantitative EEG and broadband EEG are advancing our understanding of the functional processes of the brain itself.
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Affiliation(s)
- Anteneh M Feyissa
- Department of Neurology, Mayo Clinic College of Medicine and Health Sciences, Jacksonville, FL, United States.
| | - William O Tatum
- Department of Neurology, Mayo Clinic College of Medicine and Health Sciences, Jacksonville, FL, United States
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19
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Smith ZZ, Benison AM, Bercum FM, Dudek FE, Barth DS. Progression of convulsive and nonconvulsive seizures during epileptogenesis after pilocarpine-induced status epilepticus. J Neurophysiol 2018; 119:1818-1835. [PMID: 29442558 DOI: 10.1152/jn.00721.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although convulsive seizures occurring during pilocarpine-induced epileptogenesis have received considerable attention, nonconvulsive seizures have not been closely examined, even though they may reflect the earliest signs of epileptogenesis and potentially guide research on antiepileptogenic interventions. The definition of nonconvulsive seizures based on brain electrical activity alone has been controversial. Here we define and quantify electrographic properties of convulsive and nonconvulsive seizures in the context of the acquired epileptogenesis that occurs after pilocarpine-induced status epilepticus (SE). Lithium-pilocarpine was used to induce the prolonged repetitive seizures characteristic of SE; when SE was terminated with paraldehyde, seizures returned during the 2-day period after pilocarpine treatment. A distinct latent period ranging from several days to >2 wk was then measured with continuous, long-term video-EEG. Nonconvulsive seizures dominated the onset of epileptogenesis and consistently preceded the first convulsive seizures but were still present later. Convulsive and nonconvulsive seizures had similar durations. Postictal depression (background suppression of the EEG) lasted for >100 s after both convulsive and nonconvulsive seizures. Principal component analysis was used to quantify the spectral evolution of electrical activity that characterized both types of spontaneous recurrent seizures. These studies demonstrate that spontaneous nonconvulsive seizures have electrographic properties similar to convulsive seizures and confirm that nonconvulsive seizures link the latent period and the onset of convulsive seizures during post-SE epileptogenesis in an animal model. Nonconvulsive seizures may also reflect the earliest signs of epileptogenesis in human acquired epilepsy, when intervention could be most effective. NEW & NOTEWORTHY Nonconvulsive seizures usually represent the first bona fide seizure following a latent period, dominate the early stages of epileptogenesis, and change in severity in a manner consistent with the progressive nature of epileptogenesis. This analysis demonstrates that nonconvulsive and convulsive seizures have different behavioral outcomes but similar electrographic signatures. Alternatively, epileptiform spike-wave discharges fail to recapitulate several key seizure features and represent a category of electrical activity separate from nonconvulsive seizures in this model.
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Affiliation(s)
- Zachariah Z Smith
- Department of Psychology and Neuroscience, University of Colorado , Boulder, Colorado
| | - Alexander M Benison
- Department of Psychology and Neuroscience, University of Colorado , Boulder, Colorado
| | - Florencia M Bercum
- Department of Psychology and Neuroscience, University of Colorado , Boulder, Colorado
| | - F Edward Dudek
- Department of Neurosurgery, University of Utah School of Medicine , Salt Lake City, Utah
| | - Daniel S Barth
- Department of Psychology and Neuroscience, University of Colorado , Boulder, Colorado
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20
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Clinical value and predictors of subclinical seizures in patients with temporal lobe epilepsy undergoing scalp video-EEG monitoring. J Clin Neurosci 2017; 44:214-217. [DOI: 10.1016/j.jocn.2017.06.071] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/21/2017] [Indexed: 11/20/2022]
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21
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Tramoni-Negre E, Lambert I, Bartolomei F, Felician O. Long-term memory deficits in temporal lobe epilepsy. Rev Neurol (Paris) 2017; 173:490-497. [DOI: 10.1016/j.neurol.2017.06.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 06/15/2017] [Indexed: 11/25/2022]
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22
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Twele F, Schidlitzki A, Töllner K, Löscher W. The intrahippocampal kainate mouse model of mesial temporal lobe epilepsy: Lack of electrographic seizure-like events in sham controls. Epilepsia Open 2017; 2:180-187. [PMID: 29588947 PMCID: PMC5719860 DOI: 10.1002/epi4.12044] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2017] [Indexed: 12/13/2022] Open
Abstract
Objective There is an ongoing debate about definition of seizures in experimental models of acquired epilepsy and how important adequate sham controls are in this respect. For instance, several mouse and rat strains exhibit high-voltage rhythmic spike or spike-wave discharges in the cortical electroencephalogram (EEG), which has to be considered when using such strains for induction of epilepsy by status epilepticus, traumatic brain injury, or other means. Mice developing spontaneous recurrent nonconvulsive and convulsive seizures after intrahippocampal injection of kainate are increasingly being used as a model of mesial temporal lobe epilepsy. We performed a prospective study in which EEG alterations occurring in this model were compared with the EEGs in appropriate sham controls, using hippocampal electrodes and video-EEG monitoring. Methods Experiments with intrahippocampal kainate (or saline) injections started when mice were about 8 weeks of age. Continuous video-EEG recording via hippocampal electrodes was performed 6 weeks after surgery in kainate-injected mice and sham controls, that is, at an age of about 14 weeks. Three days of continuous video-EEG monitoring were compared between kainate-injected mice and experimental controls. Results As reported previously, kainate-injected mice exhibited two types of highly frequent electrographic seizures: high-voltage sharp waves, which were often monomorphic, and polymorphic hippocampal paroxysmal discharges. In addition, generalized convulsive clinical seizures were infrequently observed. None of these electrographic or electroclinical seizures were observed in sham controls. The only infrequently observed EEG abnormalities in sham controls were isolated spikes or spike clusters, which were also recorded in epileptic mice. Significance This study rigorously demonstrates, by explicit comparison with the EEGs of sham controls, that the nonconvulsive paroxysmal events observed in this model are consequences of the induced epilepsy and not features of the EEG expected to be seen in some experimental control mice or unintentionally induced by surgical procedures.
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Affiliation(s)
- Friederike Twele
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
| | - Alina Schidlitzki
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
| | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
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Won SY, Dubinski D, Herrmann E, Cuca C, Strzelczyk A, Seifert V, Konczalla J, Freiman TM. Epileptic Seizures in Patients Following Surgical Treatment of Acute Subdural Hematoma-Incidence, Risk Factors, Patient Outcome, and Development of New Scoring System for Prophylactic Antiepileptic Treatment (GATE-24 score). World Neurosurg 2017; 101:416-424. [PMID: 28213197 DOI: 10.1016/j.wneu.2017.02.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 11/18/2022]
Abstract
OBJECT Clinically evident or subclinical seizures are common manifestations in acute subdural hematoma (aSDH); however, there is a paucity of research investigating the relationship between seizures and aSDH. The purpose of this study is 2-fold: determine incidence and predictors of seizures and then establish a guideline in patients with aSDH to standardize the decision for prophylactic antiepileptic treatment. METHOD The author analyzed 139 patients with aSDH treated from 2007 until 2015. Baseline characteristics and clinical findings including Glasgow Coma Scale (GCS) at admission, 24 hours after operation, timing of operation, anticoagulation, and Glasgow Outcome Scale at hospital discharge and after 3 months were analyzed. Multivariate logistic regression analysis was performed to detect independent predictors of seizures, and a scoring system was developed. RESULTS Of 139 patients, overall incidence of seizures was 38%, preoperatively 16% and postoperatively 24%. Ninety percent of patients with preoperative seizures were seizure free after operation for 3 months. Independent predictors of seizures were GCS <9 (odds ratio [OR] 3.3), operation after 24 hours (OR 2.0), and anticoagulation (OR 2.2). Patients with seizures had a significantly higher rate of unfavorable outcome at hospital discharge (P = 0.001) and in 3-month follow-up (P = 0.002). Furthermore, a score system (GATE-24) was developed. In patients with GCS <14, anticoagulation, or surgical treatment 24 hours after onset, a prophylactic antiepileptic treatment is recommended. CONCLUSION Occurrence of seizures affected severity and outcomes after surgical treatment of aSDH. Therefore seizure prophylaxis should be considered in high-risk patients on the basis of the GATE-24 score to promote better clinical outcome.
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Affiliation(s)
- Sae-Yeon Won
- Department of Neurosurgery, University Hospital, Goethe-University, Frankfurt am Main, Germany.
| | - Daniel Dubinski
- Department of Neurosurgery, University Hospital, Goethe-University, Frankfurt am Main, Germany
| | - Eva Herrmann
- Department of Medicine, Institute of Biostatistics and Mathematical Modelling, University Hospital, Goethe-University, Frankfurt am Main, Germany
| | - Colleen Cuca
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital, Goethe-University, Frankfurt am Main, Germany
| | - Adam Strzelczyk
- Department of Neurology and Epilepsy Center Frankfurt Rhine-Main, University Hospital, Goethe-University, Frankfurt am Main, Germany
| | - Volker Seifert
- Department of Neurosurgery, University Hospital, Goethe-University, Frankfurt am Main, Germany
| | - Juergen Konczalla
- Department of Neurosurgery, University Hospital, Goethe-University, Frankfurt am Main, Germany
| | - Thomas M Freiman
- Department of Neurosurgery, University Hospital, Goethe-University, Frankfurt am Main, Germany
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24
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Jin B, Wang S, Yang L, Shen C, Ding Y, Guo Y, Wang Z, Zhu J, Wang S, Ding M. Prevalence and predictors of subclinical seizures during scalp video-EEG monitoring in patients with epilepsy. Int J Neurosci 2016; 127:651-658. [PMID: 27569054 DOI: 10.1080/00207454.2016.1220946] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Bo Jin
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shan Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Linglin Yang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Chunhong Shen
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yao Ding
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yi Guo
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhongjin Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Junming Zhu
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Meiping Ding
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Ferastraoaru V, Schulze-Bonhage A, Lipton RB, Dümpelmann M, Legatt AD, Blumberg J, Haut SR. Termination of seizure clusters is related to the duration of focal seizures. Epilepsia 2016; 57:889-95. [PMID: 27030215 DOI: 10.1111/epi.13375] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2016] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Clustered seizures are characterized by shorter than usual interseizure intervals and pose increased morbidity risk. This study examines the characteristics of seizures that cluster, with special attention to the final seizure in a cluster. METHODS This is a retrospective analysis of long-term inpatient monitoring data from the EPILEPSIAE project. Patients underwent presurgical evaluation from 2002 to 2009. Seizure clusters were defined by the occurrence of at least two consecutive seizures with interseizure intervals of <4 h. Other definitions of seizure clustering were examined in a sensitivity analysis. Seizures were classified into three contextually defined groups: isolated seizures (not meeting clustering criteria), terminal seizure (last seizure in a cluster), and intracluster seizures (any other seizures within a cluster). Seizure characteristics were compared among the three groups in terms of duration, type (focal seizures remaining restricted to one hemisphere vs. evolving bilaterally), seizure origin, and localization concordance among pairs of consecutive seizures. RESULTS Among 92 subjects, 77 (83%) had at least one seizure cluster. The intracluster seizures were significantly shorter than the last seizure in a cluster (p = 0.011), whereas the last seizure in a cluster resembled the isolated seizures in terms of duration. Although focal only (unilateral), seizures were shorter than seizures that evolved bilaterally and there was no correlation between the seizure type and the seizure position in relation to a cluster (p = 0.762). Frontal and temporal lobe seizures were more likely to cluster compared with other localizations (p = 0.009). Seizure pairs that are part of a cluster were more likely to have a concordant origin than were isolated seizures. Results were similar for the 2 h definition of clustering, but not for the 8 h definition of clustering. SIGNIFICANCE We demonstrated that intracluster seizures are short relative to isolated seizures and terminal seizures. Frontal and temporal lobe seizures are more likely to cluster.
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Affiliation(s)
- Victor Ferastraoaru
- Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, U.S.A.,Comprehensive Epilepsy Management Center, Montefiore Medical Center, Bronx, New York, U.S.A
| | | | - Richard B Lipton
- Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, U.S.A
| | | | - Alan D Legatt
- Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, U.S.A.,Comprehensive Epilepsy Management Center, Montefiore Medical Center, Bronx, New York, U.S.A
| | - Julie Blumberg
- Epilepsy Center, University Medical Center Freiburg, Freiburg, Germany.,Department of Neuropediatrics and Muscle Disorders, University Medical Center Freiburg, Freiburg, Germany
| | - Sheryl R Haut
- Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, U.S.A.,Comprehensive Epilepsy Management Center, Montefiore Medical Center, Bronx, New York, U.S.A
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Abstract
BACKGROUND Focal epilepsies are caused by a malfunction of nerve cells localised in one part of one cerebral hemisphere. In studies, estimates of the number of individuals with focal epilepsy who do not become seizure-free despite optimal drug therapy vary according to the age of the participants and which focal epilepsies are included, but have been reported as at least 20% and in some studies up to 70%. If the epileptogenic zone can be located surgical resection offers the chance of a cure with a corresponding increase in quality of life. OBJECTIVES The primary objective is to assess the overall outcome of epilepsy surgery according to evidence from randomised controlled trials.The secondary objectives are to assess the overall outcome of epilepsy surgery according to non-randomised evidence and to identify the factors that correlate to remission of seizures postoperatively. SEARCH METHODS We searched the Cochrane Epilepsy Group Specialised Register (June 2013), the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 6), MEDLINE (Ovid) (2001 to 4 July 2013), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for relevant trials up to 4 July 2013. SELECTION CRITERIA Eligible studies were randomised controlled trials (RCTs), cohort studies or case series, with either a prospective and/or retrospective design, including at least 30 participants, a well-defined population (age, sex, seizure type/frequency, duration of epilepsy, aetiology, magnetic resonance imaging (MRI) diagnosis, surgical findings), an MRI performed in at least 90% of cases and an expected duration of follow-up of at least one year, and reporting an outcome relating to postoperative seizure control. DATA COLLECTION AND ANALYSIS Three groups of two review authors independently screened all references for eligibility, assessed study quality and risk of bias, and extracted data. Outcomes were proportion of participants achieving a good outcome according to the presence or absence of each prognostic factor of interest. We intended to combine data with risk ratios (RR) and 95% confidence intervals. MAIN RESULTS We identified 177 studies (16,253 participants) investigating the outcome of surgery for epilepsy. Four studies were RCTs (including one that randomised participants to surgery or medical treatment). The risk of bias in the RCTs was unclear or high, limiting our confidence in the evidence that addressed the primary review objective. Most of the remaining 173 non-randomised studies had a retrospective design; they were of variable size, were conducted in a range of countries, recruited a wide demographic range of participants, used a wide range of surgical techniques and used different scales used to measure outcomes. We performed quality assessment using the Effective Public Health Practice Project (EPHPP) tool and determined that most studies provided moderate or weak evidence. For 29 studies reporting multivariate analyses we used the Quality in Prognostic Studies (QUIPS) tool and determined that very few studies were at low risk of bias across the domains.In terms of freedom from seizures, one RCT found surgery to be superior to medical treatment, two RCTs found no statistically significant difference between anterior temporal lobectomy (ATL) with or without corpus callosotomy or between 2.5 cm or 3.5 cm ATL resection, and one RCT found total hippocampectomy to be superior to partial hippocampectomy. We judged the evidence from the four RCTs to be of moderate to very low quality due to the lack of information reported about the randomised trial design and the restricted study populations.Of the 16,253 participants included in this review, 10,518 (65%) achieved a good outcome from surgery; this ranged across studies from 13.5% to 92.5%. Overall, we found the quality of data in relation to the recording of adverse events to be very poor.In total, 118 studies examined between one and eight prognostic factors in univariate analysis. We found the following prognostic factors to be associated with a better post-surgical seizure outcome: an abnormal pre-operative MRI, no use of intracranial monitoring, complete surgical resection, presence of mesial temporal sclerosis, concordance of pre-operative MRI and electroencephalography (EEG), history of febrile seizures, absence of focal cortical dysplasia/malformation of cortical development, presence of tumour, right-sided resection and presence of unilateral interictal spikes. We found no evidence that history of head injury, presence of encephalomalacia, presence of vascular malformation or presence of postoperative discharges were prognostic factors of outcome. We observed variability between studies for many of our analyses, likely due to the small study sizes with unbalanced group sizes, variation in the definition of seizure outcome, definition of the prognostic factor and the influence of the site of surgery, all of which we observed to be related to postoperative seizure outcome. Twenty-nine studies reported multivariable models of prognostic factors and the direction of association of factors with outcome was generally the same as found in the univariate analyses. However, due to the different multivariable analysis approaches and selective reporting of results, meaningful comparison of multivariate analysis with univariate meta-analysis is difficult. AUTHORS' CONCLUSIONS The study design issues and limited information presented in the included studies mean that our results provide limited evidence to aid patient selection for surgery and prediction of likely surgical outcome. Future research should be of high quality, have a prospective design, be appropriately powered and focus on specific issues related to diagnostic tools, the site-specific surgical approach and other issues such as the extent of resection. Prognostic factors related to the outcome of surgery should be investigated via multivariable statistical regression modelling, where variables are selected for modelling according to clinical relevance and all numerical results of the prognostic models are fully reported. Protocols should include pre- and postoperative measures of speech and language function, cognition and social functioning along with a mental state assessment. Journal editors should not accept papers where adverse events from a medical intervention are not recorded. Improvements in the development of cancer care over the past three to four decades have been achieved by answering well-defined questions through the conduct of focused RCTs in a step-wise fashion. The same approach to surgery for epilepsy is required.
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Affiliation(s)
- Siobhan West
- Department of Paediatric Neurology, Royal Manchester Children's Hospital, Hathersage Road, Manchester, UK, M13 0JH
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Felician O, Tramoni E, Bartolomei F. Transient epileptic amnesia: Update on a slowly emerging epileptic syndrome. Rev Neurol (Paris) 2015; 171:289-97. [DOI: 10.1016/j.neurol.2014.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/11/2014] [Indexed: 11/30/2022]
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28
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Langston ME, Tatum WO. Focal seizures without awareness. Epilepsy Res 2015; 109:163-8. [DOI: 10.1016/j.eplepsyres.2014.10.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 10/14/2014] [Accepted: 10/26/2014] [Indexed: 10/24/2022]
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29
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Farooque P, Duckrow R. Subclinical seizures during intracranial EEG recording: Are they clinically significant? Epilepsy Res 2014; 108:1790-6. [DOI: 10.1016/j.eplepsyres.2014.09.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 09/09/2014] [Accepted: 09/20/2014] [Indexed: 10/24/2022]
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Seizure initiation and propagation in the pilocarpine rat model of temporal lobe epilepsy. J Neurosci 2013; 33:16409-11. [PMID: 24133247 DOI: 10.1523/jneurosci.3687-13.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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31
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Early activation of ventral hippocampus and subiculum during spontaneous seizures in a rat model of temporal lobe epilepsy. J Neurosci 2013; 33:11100-15. [PMID: 23825415 DOI: 10.1523/jneurosci.0472-13.2013] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Temporal lobe epilepsy is the most common form of epilepsy in adults. The pilocarpine-treated rat model is used frequently to investigate temporal lobe epilepsy. The validity of the pilocarpine model has been challenged based largely on concerns that seizures might initiate in different brain regions in rats than in patients. The present study used 32 recording electrodes per rat to evaluate spontaneous seizures in various brain regions including the septum, dorsomedial thalamus, amygdala, olfactory cortex, dorsal and ventral hippocampus, substantia nigra, entorhinal cortex, and ventral subiculum. Compared with published results from patients, seizures in rats tended to be shorter, spread faster and more extensively, generate behavioral manifestations more quickly, and produce generalized convulsions more frequently. Similarities to patients included electrographic waveform patterns at seizure onset, variability in sites of earliest seizure activity within individuals, and variability in patterns of seizure spread. Like patients, the earliest seizure activity in rats was recorded most frequently within the hippocampal formation. The ventral hippocampus and ventral subiculum displayed the earliest seizure activity. Amygdala, olfactory cortex, and septum occasionally displayed early seizure latencies, but not above chance levels. Substantia nigra and dorsomedial thalamus demonstrated consistently late seizure onsets, suggesting their unlikely involvement in seizure initiation. The results of the present study reveal similarities in onset sites of spontaneous seizures in patients with temporal lobe epilepsy and pilocarpine-treated rats that support the model's validity.
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Rocamora R, Andrzejak RG, Jiménez-Conde J, Elger CE. Sleep modulation of epileptic activity in mesial and neocortical temporal lobe epilepsy: a study with depth and subdural electrodes. Epilepsy Behav 2013; 28:185-90. [PMID: 23751358 DOI: 10.1016/j.yebeh.2013.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/11/2013] [Accepted: 04/12/2013] [Indexed: 10/26/2022]
Abstract
This study characterizes the spatial-temporal distribution of epileptic activity in mesial and neocortical temporal lobe epilepsy (TLE) assessed by subdural and depth electrodes during sleep. We determined in 13 patients the frequency, lateralization, and localization of interictal epileptic discharges (IEDs). As compared to the waking state, IEDs increased in light sleep (196%, p < 0.05) and in deep sleep (601%, p < 0.05) but did not change significantly in REM sleep (-8.33%, p = 0.94). From 11 patients with unilateral TLE, in all cases, IEDs lateralized to the seizure onset side during REM sleep and the waking state. In mesial TLE, IEDs tended to shift in an anterior-posterior axis and remained always localized in the amygdalo-hippocampal complex. By contrast, in neocortical TLE, the maximal activity moved in a mesial-lateral axis between neocortical and mesial structures. Twenty-six seizures were registered in 7 patients, 22 of which occurred in light sleep and 4 in wakefulness, but none occurred in deep or REM sleep.
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Affiliation(s)
- Rodrigo Rocamora
- Epilepsy Monitoring Unit, Department of Neurology, Hospital del Mar, Passeig Maritim 25-29, 08003 Barcelona, Spain.
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Prediction of seizure likelihood with a long-term, implanted seizure advisory system in patients with drug-resistant epilepsy: a first-in-man study. Lancet Neurol 2013; 12:563-71. [PMID: 23642342 DOI: 10.1016/s1474-4422(13)70075-9] [Citation(s) in RCA: 482] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Seizure prediction would be clinically useful in patients with epilepsy and could improve safety, increase independence, and allow acute treatment. We did a multicentre clinical feasibility study to assess the safety and efficacy of a long-term implanted seizure advisory system designed to predict seizure likelihood and quantify seizures in adults with drug-resistant focal seizures. METHODS We enrolled patients at three centres in Melbourne, Australia, between March 24, 2010, and June 21, 2011. Eligible patients had between two and 12 disabling partial-onset seizures per month, a lateralised epileptogenic zone, and no history of psychogenic seizures. After devices were surgically implanted, patients entered a data collection phase, during which an algorithm for identification of periods of high, moderate, and low seizure likelihood was established. If the algorithm met performance criteria (ie, sensitivity of high-likelihood warnings greater than 65% and performance better than expected through chance prediction of randomly occurring events), patients then entered an advisory phase and received information about seizure likelihood. The primary endpoint was the number of device-related adverse events at 4 months after implantation. Our secondary endpoints were algorithm performance at the end of the data collection phase, clinical effectiveness (measures of anxiety, depression, seizure severity, and quality of life) 4 months after initiation of the advisory phase, and longer-term adverse events. This trial is registered with ClinicalTrials.gov, number NCT01043406. FINDINGS We implanted 15 patients with the advisory system. 11 device-related adverse events were noted within four months of implantation, two of which were serious (device migration, seroma); an additional two serious adverse events occurred during the first year after implantation (device-related infection, device site reaction), but were resolved without further complication. The device met enabling criteria in 11 patients upon completion of the data collection phase, with high likelihood performance estimate sensitivities ranging from 65% to 100%. Three patients' algorithms did not meet performance criteria and one patient required device removal because of an adverse event before sufficient training data were acquired. We detected no significant changes in clinical effectiveness measures between baseline and 4 months after implantation. INTERPRETATION This study showed that intracranial electroencephalographic monitoring is feasible in ambulatory patients with drug-resistant epilepsy. If these findings are replicated in larger, longer studies, accurate definition of preictal electrical activity might improve understanding of seizure generation and eventually lead to new management strategies. FUNDING NeuroVista.
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Brotherstone R, McLellan A. Parasympathetic alteration during sub-clinical seizures. Seizure 2012; 21:391-8. [PMID: 22494870 DOI: 10.1016/j.seizure.2012.03.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 03/19/2012] [Accepted: 03/20/2012] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Autonomic instability is considered a contributing factor in sudden unexpected death in epilepsy (SUDEP). The aim of this pilot study was to measure parasympathetic activity in sub-clinical seizures to investigate autonomic instability. MATERIALS AND METHODS A prospective study based on Video-electroencephalography (EEG)/electrocardiography (ECG)/oxygen saturation (SAO2) recordings was selected from patients having sub-clinical seizures during stage 3 or 4 sleep. We analysed R-R intervals in the ECG from 1-min prior to the electrographic onset to the end of sub-clinical seizures. Matched non-ictal R-R baseline measurements were selected from stages 3 or 4 sleep. R-R interval data were analysed using NeuroScope software providing a cardiac index of parasympathetic activity (CIPA). BioSignal short-term heart rate variability (HRV) software was used to analyse the same R-R interval data previously analysed using NeuroScope except that sub-clinical seizure data was embedded within 5-min epochs and compared to 5-min epochs of non-ictal measurements. RESULTS A total of 33 sub-clinical seizures were recorded from 11 patients comprising 19 generalised sub-clinical seizures (2 patients), 9 right temporal lobe sub-clinical seizures (5 patients) and 5 left temporal lobe sub-clinical seizures (4 patients) were compared to matched non-ictal measurements. Parasympathetic activity was clearly altered during total sub-clinical seizures in terms of the CIPA (p<0.001) and 5-min HRV high frequency (HF) % (p=0.026) measures. Generalised sub-clinical seizures resulted in increased cardiac parasympathetic activity whereas temporal lobe seizures were associated with a decrease in parasympathetic activity. CONCLUSION This pilot study indicates that parasympathetic changes occur during sub-clinical seizures. Generalised sub-clinical seizures may be associated with more autonomic instability compared to temporal lobe sub-clinical seizures.
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Affiliation(s)
- Ruth Brotherstone
- Department of Clinical Neurophysiology, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom.
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Feldwisch-Drentrup H, Ihle M, Quyen MLV, Teixeira C, Dourado A, Timmer J, Sales F, Navarro V, Schulze-Bonhage A, Schelter B. Anticipating the unobserved: prediction of subclinical seizures. Epilepsy Behav 2011; 22 Suppl 1:S119-26. [PMID: 22078512 DOI: 10.1016/j.yebeh.2011.08.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 08/23/2011] [Indexed: 11/26/2022]
Abstract
Subclinical seizures (SCS) have rarely been considered in the diagnosis and therapy of epilepsy and have not been systematically analyzed in studies on seizure prediction. Here, we investigate whether predictions of subclinical seizures are feasible and how their occurrence may affect the performance of prediction algorithms. Using the European database of long-term recordings of surface and invasive electroencephalography data, we analyzed the data from 21 patients with SCS, including in total 413 clinically manifest seizures (CS) and 3341 SCS. Based on the mean phase coherence we investigated the predictive performance of CS and SCS. The two types of seizures had similar prediction sensitivities. Significant performance was found considerably more often for SCS than for CS, especially for patients with invasive recordings. When analyzing false alarms triggered by predicting CS, a significant number of these false predictions were followed by SCS for 9 of 21 patients. Although currently observed prediction performance may not be deemed sufficient for clinical applications for the majority of the patients, it can be concluded that the prediction of SCS is feasible on a similar level as for CS and allows a prediction of more of the seizures impairing patients, possibly also reducing the number of false alarms that were in fact correct predictions of CS. This article is part of a Supplemental Special Issue entitled The Future of Automated Seizure Detection and Prediction.
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36
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Nagarajan L, Ghosh S, Palumbo L. Ictal electroencephalograms in neonatal seizures: characteristics and associations. Pediatr Neurol 2011; 45:11-6. [PMID: 21723453 DOI: 10.1016/j.pediatrneurol.2011.01.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 12/14/2010] [Accepted: 01/17/2011] [Indexed: 11/20/2022]
Abstract
The characteristics of ictal electroencephalograms in 160 neonatal seizures of 43 babies were correlated with mortality and neurodevelopmental outcomes. Neonatal seizures are focal at onset, most frequently temporal, and often occur during sleep. Twenty-one percent of babies with seizures died, and 76% of survivors manifested neurodevelopmental impairment during 2-6-year follow-up. A low-amplitude ictal electroencephalogram discharge was associated with increased mortality, and a frequency of <2 Hz with increased morbidity. Status epilepticus, ictal fractions, multiple foci, and bihemispheric involvement did not influence outcomes. Of 160 seizures, 99 exhibited no associated clinical features (electrographic seizures). Neonatal seizures with clinical correlates (electroclinical seizures) exhibited a higher amplitude and frequency of ictal electroencephalogram discharge than electrographic seizures. During electroclinical seizures, the ictal electroencephalogram was more likely to involve larger areas of the brain and to cross the midline. Mortality and morbidity were similar in babies with electroclinical and electrographic seizures, emphasizing the need to diagnose and treat both types. Ictal electroencephalogram topography has implications for electrode application during limited-channel, amplitude-integrated electroencephalograms. We recommend temporal and paracentral electrodes. Video electroencephalograms are important in diagnosing neonatal seizures and providing useful information regarding ictal electroencephalogram characteristics.
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Affiliation(s)
- Lakshmi Nagarajan
- Department of Neurology, Princess Margaret Hospital for Children, Perth, Western Australia, Australia.
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Clinical value of subclinical seizures in children with focal epilepsy. Epilepsy Res 2011; 95:82-5. [DOI: 10.1016/j.eplepsyres.2011.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Revised: 02/21/2011] [Accepted: 03/04/2011] [Indexed: 11/17/2022]
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Maroso M, Balosso S, Ravizza T, Iori V, Wright CI, French J, Vezzani A. Interleukin-1β biosynthesis inhibition reduces acute seizures and drug resistant chronic epileptic activity in mice. Neurotherapeutics 2011; 8:304-15. [PMID: 21431948 PMCID: PMC3101825 DOI: 10.1007/s13311-011-0039-z] [Citation(s) in RCA: 221] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Experimental evidence and clinical observations indicate that brain inflammation is an important factor in epilepsy. In particular, induction of interleukin-converting enzyme (ICE)/caspase-1 and activation of interleukin (IL)-1β/IL-1 receptor type 1 axis both occur in human epilepsy, and contribute to experimentally induced acute seizures. In this study, the anticonvulsant activity of VX-765 (a selective ICE/caspase-1 inhibitor) was examined in a mouse model of chronic epilepsy with spontaneous recurrent epileptic activity refractory to some common anticonvulsant drugs. Moreover, the effects of this drug were studied in one acute model of seizures in mice, previously shown to involve activation of ICE/caspase-1. Quantitative analysis of electroencephalogram activity was done in mice exposed to acute seizures or those developing chronic epileptic activity after status epilepticus to assess the anticonvulsant effects of systemic administration of VX-765. Histological and immunohistochemical analysis of brain tissue was carried out at the end of pharmacological experiments in epileptic mice to evaluate neuropathology, glia activation and IL-1β expression, and the effect of treatment. Repeated systemic administration of VX-765 significantly reduced chronic epileptic activity in mice in a dose-dependent fashion (12.5-200 mg/kg). This effect was observed at doses ≥ 50 mg/kg, and was reversible with discontinuation of the drug. Maximal drug effect was associated with inhibition of IL-1β synthesis in activated astrocytes. The same dose regimen of VX-765 also reduced acute seizures in mice and delayed their onset time. These results support a new target system for anticonvulsant pharmacological intervention to control epileptic activity that does not respond to some common anticonvulsant drugs.
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Affiliation(s)
- Mattia Maroso
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milano, 20156 Italy
| | - Silvia Balosso
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milano, 20156 Italy
| | - Teresa Ravizza
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milano, 20156 Italy
| | - Valentina Iori
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milano, 20156 Italy
| | | | - Jacqueline French
- New York University Comprehensive Epilepsy Center, New York, New York 10016 USA
| | - Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milano, 20156 Italy
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Tramoni E, Felician O, Barbeau EJ, Guedj E, Guye M, Bartolomei F, Ceccaldi M. Long-term consolidation of declarative memory: insight from temporal lobe epilepsy. Brain 2011; 134:816-31. [DOI: 10.1093/brain/awr002] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Parisi P. News on the horizon is not good: interictal epileptic discharges continue to be unaffected by the therapeutic level of AEDs. Epilepsia 2010; 51:933-4. [PMID: 20536530 DOI: 10.1111/j.1528-1167.2009.02418.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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When "long-term memory" no longer means "forever": analysis of accelerated long-term forgetting in a patient with temporal lobe epilepsy. Neuropsychologia 2010; 48:1707-15. [PMID: 20178808 DOI: 10.1016/j.neuropsychologia.2010.02.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 02/13/2010] [Accepted: 02/16/2010] [Indexed: 11/22/2022]
Abstract
Classical amnesia involves a difficulty in transferring information to long-term memory and can be detected with standard clinical tests. However, there are some patients who pass these tests but nonetheless show longer-term memory impairments. A case study is presented of a patient, RY, with temporal lobe epilepsy, who exhibited such a profile of "accelerated long-term forgetting". To investigate the effect of recalling information on later retention, recall and recognition for pairs of novel stories were tested at five intervals ranging from 30 min to 4 weeks; we also manipulated whether or not recall and recognition were repeatedly tested for stories. Two studies are reported, one before RY commenced treatment with anticonvulsant medication, and one following 6 months of treatment. Very similar memory profiles were observed in both settings. Against a background of above average cognitive function, results showed that RY's free recall, although initially average or above, was significantly impaired at extended delays (within 24h) for non-repeatedly recalled episodic information. However, this contrasted with normal performance for information that had been repeatedly recalled. An unresolved issue in the field is the impact of anticonvulsant medication on alleviating long-term forgetting, and the current study shows that anticonvulsant medication can have negligible beneficial effects in improving the rate of long-term forgetting in this type of patient. In addition, our study highlights the possible protective effect of active review of recent episodic memories.
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Tyvaert L, LeVan P, Dubeau F, Gotman J. Noninvasive dynamic imaging of seizures in epileptic patients. Hum Brain Mapp 2010; 30:3993-4011. [PMID: 19507156 DOI: 10.1002/hbm.20824] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Epileptic seizures are due to abnormal synchronized neuronal discharges. Techniques measuring electrical changes are commonly used to analyze seizures. Neuronal activity can be also defined by concomitant hemodynamic and metabolic changes. Simultaneous electroencephalogram (EEG)-functional MRI (fMRI) measures noninvasively with a high-spatial resolution BOLD changes during seizures in the whole brain. Until now, only a static image representing the whole seizure was provided. We report in 10 focal epilepsy patients a new approach to dynamic imaging of seizures including the BOLD time course of seizures and the identification of brain structures involved in seizure onset and discharge propagation. The first activation was observed in agreement with the expected location of the focus based on clinical and EEG data (three intracranial recordings), thus providing validity to this approach. The BOLD signal preceded ictal EEG changes in two cases. EEG-fMRI may detect changes in smaller and deeper structures than scalp EEG, which can only record activity form superficial cortical areas. This method allowed us to demonstrate that seizure onset zone was limited to one structure, thus supporting the concept of epileptic focus, but that a complex neuronal network was involved during propagation. Deactivations were also found during seizures, usually appearing after the first activation in areas close or distant to the activated regions. Deactivations may correspond to actively inhibited regions or to functional disconnection from normally active regions. This new noninvasive approach should open the study of seizure generation and propagation mechanisms in the whole brain to groups of patients with focal epilepsies.
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Affiliation(s)
- Louise Tyvaert
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4.
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Adjei P, Surges R, Scott CA, Kallis C, Shorvon S, Walker MC. Do subclinical electrographic seizure patterns affect heart rate and its variability? Epilepsy Res 2009; 87:281-5. [DOI: 10.1016/j.eplepsyres.2009.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 08/11/2009] [Accepted: 08/22/2009] [Indexed: 10/20/2022]
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Goldman AM, Glasscock E, Yoo J, Chen TT, Klassen TL, Noebels JL. Arrhythmia in heart and brain: KCNQ1 mutations link epilepsy and sudden unexplained death. Sci Transl Med 2009; 1:2ra6. [PMID: 20368164 PMCID: PMC2951754 DOI: 10.1126/scitranslmed.3000289] [Citation(s) in RCA: 214] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Sudden unexplained death is a catastrophic complication of human idiopathic epilepsy, causing up to 18% of patient deaths. A molecular mechanism and an identified therapy have remained elusive. Here, we find that epilepsy occurs in mouse lines bearing dominant human LQT1 mutations for the most common form of cardiac long QT syndrome, which causes syncopy and sudden death. KCNQ1 encodes the cardiac KvLQT1 delayed rectifier channel, which has not been previously found in the brain. We have shown that, in these mice, this channel is found in forebrain neuronal networks and brainstem nuclei, regions in which a defect in the ability of neurons to repolarize after an action potential, as would be caused by this mutation, can produce seizures and dysregulate autonomic control of the heart. That long QT syndrome mutations in KCNQ1 cause epilepsy reveals the dual arrhythmogenic potential of an ion channelopathy coexpressed in heart and brain and motivates a search for genetic diagnostic strategies to improve risk prediction and prevention of early mortality in persons with seizure disorders of unknown origin.
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Affiliation(s)
- A M Goldman
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
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Akman CI, Montenegro MA, Jacob S, Eck K, McBrian D, Chiriboga CA, Patterson MC. Subclinical seizures in children diagnosed with localization-related epilepsy: clinical and EEG characteristics. Epilepsy Behav 2009; 16:86-98. [PMID: 19632903 DOI: 10.1016/j.yebeh.2009.06.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 06/08/2009] [Accepted: 06/13/2009] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Subclinical seizures (SCSs) are characterized by paroxysmal rhythmic epileptiform discharges that evolve in time and space in the absence of objective clinical manifestation or report of a seizure. The aim of this study was to evaluate the frequency and characteristics of SCSs in children with localization-related epilepsy (LRE). METHODS The results of video/EEG monitoring were reviewed to identify patients with SCS. We identified 187 children diagnosed with LRE, in 32 of whom SCSs were reported in the EEG recording. RESULTS SCSs were reported only in the children who had received a diagnosis of either symptomatic or cryptogenic LRE. All children had a history of clinical seizure(s). The ictal onset of SCSs was most frequent from the temporal and frontal lobes. SCSs were lateralized to the left hemispheres in 19, right hemisphere in 8, and both hemispheres independently in 5 children. SCSs were more often reported in young children, and associated with a history of developmental delay, infantile spasms, and frequent seizures. EEG abnormalities included background slowing and lack of normal sleep architecture in addition to the epileptiform activity. Seizure freedom was reported less often in children with SCSs. Six patients seizure free at the time of the admission were found to have SCSs. CONCLUSION Subclinical seizures are not uncommon in children with LRE, in particular, with younger age, developmental disability, and medically refractory clinical course. Video/EEG monitoring will be informative in selected children with LRE to assess the seizure frequency more accurately.
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Affiliation(s)
- Cigdem I Akman
- Comprehensive Epilepsy Center, Department of Neurology, Columbia University College of Physician and Surgeons, New York, NY, USA.
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LeVan P, Tyvaert L, Moeller F, Gotman J. Independent component analysis reveals dynamic ictal BOLD responses in EEG-fMRI data from focal epilepsy patients. Neuroimage 2009; 49:366-78. [PMID: 19647798 DOI: 10.1016/j.neuroimage.2009.07.064] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 07/16/2009] [Accepted: 07/24/2009] [Indexed: 10/20/2022] Open
Abstract
INTRODUCTION Seizures occur rarely during EEG-fMRI acquisitions of epilepsy patients, but can potentially offer a better estimation of the epileptogenic zone than interictal activity. Independent component analysis (ICA) is a data-driven method that imposes minimal constraints on the hemodynamic response function (HRF). In particular, the investigation of HRFs with clear peaks, but varying latency, may be used to differentiate the ictal focus from propagated activity. METHODS ICA was applied on ictal EEG-fMRI data from 15 patients. Components related to seizures were identified by fitting an HRF to the component time courses at the time of the ictal EEG events. HRFs with a clear peak were used to derive maps of significant BOLD responses and their associated peak delay. The results were then compared with those obtained from a general linear model (GLM) method. Concordance with the presumed epileptogenic focus was also assessed. RESULTS The ICA maps were significantly correlated with the GLM maps for each patient (Spearman's test, p<0.05). The ictal BOLD responses identified by ICA always included the presumed epileptogenic zone, but were also more widespread, accounting for 20.3% of the brain volume on average. The method provided a classification of the components as a function of peak delay. BOLD response clusters associated with early HRF peaks were concordant with the suspected epileptogenic focus, while subsequent HRF peaks may correspond to ictal propagation. CONCLUSION ICA applied to EEG-fMRI can detect areas of significant BOLD response to ictal events without having to predefine an HRF. By estimating the HRF peak time in each identified region, the method could also potentially provide a dynamic analysis of ictal BOLD responses, distinguishing onset from propagated activity.
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Affiliation(s)
- Pierre LeVan
- Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, Canada.
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Bleasel A. Seizures, EEG Events, and the Ketogenic Diet: Response. Epilepsia 2009; 50:332. [DOI: 10.1111/j.1528-1167.2008.01873.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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