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Jia M, Liu W, Duan J, Chen L, Chen CLP, Wang Q, Zhou Z. Efficient graph convolutional networks for seizure prediction using scalp EEG. Front Neurosci 2022; 16:967116. [PMID: 35979333 PMCID: PMC9376592 DOI: 10.3389/fnins.2022.967116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 07/08/2022] [Indexed: 11/23/2022] Open
Abstract
Epilepsy is a chronic brain disease that causes persistent and severe damage to the physical and mental health of patients. Daily effective prediction of epileptic seizures is crucial for epilepsy patients especially those with refractory epilepsy. At present, a large number of deep learning algorithms such as Convolutional Neural Networks and Recurrent Neural Networks have been used to predict epileptic seizures and have obtained better performance than traditional machine learning methods. However, these methods usually transform the Electroencephalogram (EEG) signal into a Euclidean grid structure. The conversion suffers from loss of adjacent spatial information, which results in deep learning models requiring more storage and computational consumption in the process of information fusion after information extraction. This study proposes a general Graph Convolutional Networks (GCN) model architecture for predicting seizures to solve the problem of oversized seizure prediction models based on exploring the graph structure of EEG signals. As a graph classification task, the network architecture includes graph convolution layers that extract node features with one-hop neighbors, pooling layers that summarize abstract node features; and fully connected layers that implement classification, resulting in superior prediction performance and smaller network size. The experiment shows that the model has an average sensitivity of 96.51%, an average AUC of 0.92, and a model size of 15.5 k on 18 patients in the CHB-MIT scalp EEG dataset. Compared with traditional deep learning methods, which require a large number of parameters and computational effort and are demanding in terms of storage space and energy consumption, this method is more suitable for implementation on compact, low-power wearable devices as a standard process for building a generic low-consumption graph network model on similar biomedical signals. Furthermore, the edge features of graphs can be used to make a preliminary determination of locations and types of discharge, making it more clinically interpretable.
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Affiliation(s)
- Manhua Jia
- School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing, China
| | - Wenjian Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Junwei Duan
- College of Information Science and Technology, Jinan University, Guangzhou, China
| | - Long Chen
- Faculty of Science and Technology, University of Macau, Taipa, Macau SAR, China
| | - C. L. Philip Chen
- School of Computer Science and Engineering, South China University of Technology, Guangzhou, China
| | - Qun Wang
- School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing, China
- *Correspondence: Qun Wang
| | - Zhiguo Zhou
- School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing, China
- Zhiguo Zhou
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Jber M, Habibabadi JM, Sharifpour R, Marzbani H, Hassanpour M, Seyfi M, Mobarakeh NM, Keihani A, Hashemi-Fesharaki SS, Ay M, Nazem-Zadeh MR. Temporal and extratemporal atrophic manifestation of temporal lobe epilepsy using voxel-based morphometry and corticometry: clinical application in lateralization of epileptogenic zone. Neurol Sci 2021; 42:3305-3325. [PMID: 33389247 DOI: 10.1007/s10072-020-05003-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 12/14/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Advances in MRI acquisition and data processing have become important for revealing brain structural changes. Previous studies have reported widespread structural brain abnormalities and cortical thinning in patients with temporal lobe epilepsy (TLE), as the most common form of focal epilepsy. METHODS In this research, healthy control cases (n = 20) and patients with left TLE (n = 19) and right TLE (n = 14) were recruited, all underwent 3.0 T MRI with magnetization-prepared rapid gradient echo sequence to acquire T1-weighted images. Morphometric alterations in gray matter were identified using voxel-based morphometry (VBM). Volumetric alterations in subcortical structures and cortical thinning were also determined. RESULTS Patients with left TLE demonstrated more prevailing and widespread changes in subcortical volumes and cortical thickness than right TLE, mainly in the left hemisphere, compared to the healthy group. Both VBM analysis and subcortical volumetry detected significant hippocampal atrophy in ipsilateral compared to contralateral side in TLE group. In addition to hippocampus, subcortical volumetry found the thalamus and pallidum bilaterally vulnerable to the TLE. Furthermore, the TLE patients underwent cortical thinning beyond the temporal lobe, affecting gray matter cortices in frontal, parietal, and occipital lobes in the majority of patients, more prevalently for left TLE cases. Exploiting volume changes in individual patients in the hippocampus alone led to 63.6% sensitivity and 100% specificity for lateralization of TLE. CONCLUSION Alteration of gray matter volumes in subcortical regions and neocortical temporal structures and also cortical gray matter thickness were evidenced as common effects of epileptogenicity, as manifested by the majority of cases in this study.
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Affiliation(s)
- Majdi Jber
- Medical School, International Campus, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Roya Sharifpour
- Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Molecular and Cellular Imaging, Advanced Medical Technologies and Equipment Institute (AMTEI), Tehran University of Medical Sciences, Tehran, Iran
| | - Hengameh Marzbani
- Department of Biomedical Engineering, Amirkabir University of Technology (AUT), Tehran, Iran
| | - Masoud Hassanpour
- Research Center for Molecular and Cellular Imaging, Advanced Medical Technologies and Equipment Institute (AMTEI), Tehran University of Medical Sciences, Tehran, Iran
| | - Milad Seyfi
- Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Molecular and Cellular Imaging, Advanced Medical Technologies and Equipment Institute (AMTEI), Tehran University of Medical Sciences, Tehran, Iran
| | - Neda Mohammadi Mobarakeh
- Research Center for Molecular and Cellular Imaging, Advanced Medical Technologies and Equipment Institute (AMTEI), Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmedreza Keihani
- Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mohammadreza Ay
- Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran
- Research Center for Molecular and Cellular Imaging, Advanced Medical Technologies and Equipment Institute (AMTEI), Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Reza Nazem-Zadeh
- Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.
- Research Center for Molecular and Cellular Imaging, Advanced Medical Technologies and Equipment Institute (AMTEI), Tehran University of Medical Sciences, Tehran, Iran.
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Spring AM, Pittman DJ, Bessemer R, Federico P. Graph index complexity as a novel surrogate marker of high frequency oscillations in delineating the seizure onset zone. Clin Neurophysiol 2019; 131:78-87. [PMID: 31756595 DOI: 10.1016/j.clinph.2019.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/09/2019] [Accepted: 09/06/2019] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To investigate the Graph Index Complexity (uGIC) as a marker of high frequency oscillatory (HFO) activity, the seizure onset zone (SOZ), and surgical outcome. METHODS The SOZ, rates of HFOs at two thresholds (broad, strict), and uGIC were determined using EEG data from 41 patients. The correlation between HFOs and uGIC were calculated. HFOs and uGIC were compared within and outside the SOZ. Postsurgical outcome was compared to the colocalization of HFOs and resected SOZ. RESULTS There was significant correlation between uGIC and both broad (r = 0.69, p < 0.0005) and strict HFOs (r = 0.48, p < 0.0005). All were significantly greater within the SOZ overall, but only in 17/41 (strict, uGIC) or 18/41 (broad) patients. HFO markers were significantly greater within the SOZ for 8/15 patients with positive postsurgical outcomes, but not for any patients with negative outcomes (0/5). CONCLUSION The uGIC is a marker of HFO activity, while HFOs and uGIC are markers of the SOZ overall. Colocalization of HFOs and the SOZ has strong positive predictive value for postsurgical outcome, but poor negative predictive value. SIGNIFICANCE The uGIC is an objective surrogate marker of HFO activity independent of identifying discrete HFO events.
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Affiliation(s)
- Aaron M Spring
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada
| | - Daniel J Pittman
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada
| | - Robin Bessemer
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada
| | - Paolo Federico
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada; Department of Radiology, University of Calgary, Calgary, AB, Canada.
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Fraser-Rini J, Ochoa J. Panic Attack as the Sole Manifestation of Epilepsy Localized to the Nondominant Temporal Region. J Neuropsychiatry Clin Neurosci 2019; 32:309-311. [PMID: 31726919 DOI: 10.1176/appi.neuropsych.19070158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James Fraser-Rini
- The Department of Neurology, College of Medicine, University of South Alabama, Mobile, Ala. (Fraser-Rini, Ochoa)
| | - Juan Ochoa
- The Department of Neurology, College of Medicine, University of South Alabama, Mobile, Ala. (Fraser-Rini, Ochoa)
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Gong A, Liu J, Li F, Liu F, Jiang C, Fu Y. Correlation Between Resting-state Electroencephalographic Characteristics and Shooting Performance. Neuroscience 2017; 366:172-183. [PMID: 29079062 DOI: 10.1016/j.neuroscience.2017.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/28/2017] [Accepted: 10/13/2017] [Indexed: 11/30/2022]
Abstract
According to the theories of neural plasticity and neural efficiency, professional skill training improves performance by strengthening the underlying neural mechanisms. Therefore, subjects trained professionally may exhibit changes in resting-state neurophysiological characteristics closely related to performance. To test this notion, the resting-state electroencephalogram (EEG) was measured from 35 rifle shooters after the same training regimen, and resting-state EEG characteristics were analyzed for correlations with shooting performance. The results showed a significant linear correlation between shooting performance and the coherence of electrode channels C3 and T3 in the beta1 band (r = 0.74, P < 4.2 × 10-6). There was also a significant linear correlation between the characteristic path length of the resting-state theta band brain network and shooting performance (r = 0.56, P < 0.0005). This study identifies potential neural mechanisms underlying successful shooting and a new method for predicting and evaluating performance based on EEG characteristics.
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Affiliation(s)
- Anmin Gong
- School of Science, Engineering University of Chinese People's Armed Police Force, China.
| | - Jianping Liu
- School of Science, Engineering University of Chinese People's Armed Police Force, China
| | - Fangbo Li
- School of Science, Engineering University of Chinese People's Armed Police Force, China
| | - Fangyi Liu
- School of Science, Engineering University of Chinese People's Armed Police Force, China
| | - Changhao Jiang
- Key Laboratory of Sports Performance Evaluation and Technical Analysis, Capital Institute of Physical Education, China
| | - Yunfa Fu
- School of Automation and Information Engineering, Kunming University of Science and Technology, China
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Chi Y, Wu B, Guan J, Xiao K, Lu Z, Li X, Xu Y, Xue S, Xu Q, Rao J, Guo Y. Establishment of a rhesus monkey model of chronic temporal lobe epilepsy using repetitive unilateral intra-amygdala kainic acid injections. Brain Res Bull 2017; 134:273-282. [PMID: 28842304 DOI: 10.1016/j.brainresbull.2017.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 08/09/2017] [Accepted: 08/18/2017] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) is a common type of acquired epilepsy refractory to medical treatment. As such, establishing animal models of this disease is critical to developing new and effective treatment modalities. Because of their small head size, rodents are not suitable for comprehensive electroencephalography (EEG) evaluation via scalp or subdural electrodes. Therefore, a larger primate model that closely recapitulates signs of TLE is needed; here we describe a rhesus monkey model resembling chronic TLE. METHODS Eight monkeys were divided into two groups: kainic acid (KA) group (n=6) and saline control group (n=2). Intra-amygdala KA injections were performed biweekly via an Ommaya device until obvious epileptiform discharges were recorded. Video-EEG recording was conducted intermittently throughout the experiment using both scalp and subdural electrodes. Brains were then analyzed for Nissl and glial fibrillary acid protein (GFAP) immunostaining. RESULTS After 2-4 injections of KA (approximately 1.2-2.4mg, 0.12-0.24mg/kg), interictal epileptiform discharges (IEDs) were recorded in all KA-treated animals. Spontaneous recurrent seizures (SRSs) accompanied by symptoms mimicking temporal lobe absence (undetectable without EEG recording), but few mild motor signs, were recorded in 66.7% (four of six) KA-treated animals. Both IEDs and seizures indicated a primary epileptic zone in the right temporal region and contralateral discharges were later detected. Segmental pyramidal cell loss and gliosis were detected in the brain of a KA-treated monkey. CONCLUSIONS Through a modified protocol of unilateral repetitive intra-amygdala KA injections, a rhesus monkey model with similar behavioral and brain electrical features as TLE was developed.
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Affiliation(s)
- Yajie Chi
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China; Department of Neurosurgery, Shunde Hospital of Southern Medical University, Foshan, 528300, China
| | - Bolin Wu
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Jianwei Guan
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Kuntai Xiao
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Ziming Lu
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Xiao Li
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Yuting Xu
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Shan Xue
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.
| | - Qiang Xu
- Department of Neurosurgery, Affiliated Shunde Heping Surgical Hospital of GUCM, Foshan, 528308, China.
| | - Junhua Rao
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, 510282, China.
| | - Yanwu Guo
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.
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Interrater reliability of visually evaluated high frequency oscillations. Clin Neurophysiol 2017; 128:433-441. [DOI: 10.1016/j.clinph.2016.12.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 11/13/2016] [Accepted: 12/15/2016] [Indexed: 02/01/2023]
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Feng R, Hu J, Pan L, Wu J, Lang L, Jiang S, Gu X, Guo J, Zhou L. Application of 256-channel dense array electroencephalographic source imaging in presurgical workup of temporal lobe epilepsy. Clin Neurophysiol 2016; 127:108-116. [DOI: 10.1016/j.clinph.2015.03.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 02/26/2015] [Accepted: 03/13/2015] [Indexed: 11/27/2022]
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Muldoon SF, Villette V, Tressard T, Malvache A, Reichinnek S, Bartolomei F, Cossart R. GABAergic inhibition shapes interictal dynamics in awake epileptic mice. Brain 2015; 138:2875-90. [PMID: 26280596 DOI: 10.1093/brain/awv227] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/22/2015] [Indexed: 12/12/2022] Open
Abstract
Epilepsy is characterized by recurrent seizures and brief, synchronous bursts called interictal spikes that are present in-between seizures and observed as transient events in EEG signals. While GABAergic transmission is known to play an important role in shaping healthy brain activity, the role of inhibition in these pathological epileptic dynamics remains unclear. Examining the microcircuits that participate in interictal spikes is thus an important first step towards addressing this issue, as the function of these transient synchronizations in either promoting or prohibiting seizures is currently under debate. To identify the microcircuits recruited in spontaneous interictal spikes in the absence of any proconvulsive drug or anaesthetic agent, we combine a chronic model of epilepsy with in vivo two-photon calcium imaging and multiunit extracellular recordings to map cellular recruitment within large populations of CA1 neurons in mice free to run on a self-paced treadmill. We show that GABAergic neurons, as opposed to their glutamatergic counterparts, are preferentially recruited during spontaneous interictal activity in the CA1 region of the epileptic mouse hippocampus. Although the specific cellular dynamics of interictal spikes are found to be highly variable, they are consistently associated with the activation of GABAergic neurons, resulting in a perisomatic inhibitory restraint that reduces neuronal spiking in the principal cell layer. Given the role of GABAergic neurons in shaping brain activity during normal cognitive function, their aberrant unbalanced recruitment during these transient events could have important downstream effects with clinical implications.
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Affiliation(s)
- Sarah Feldt Muldoon
- 1 Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France 2 Aix-Marseille Université, Unité Mixte de Recherche S901, 13009 Marseille, France 3 Institut de Neurobiologie de la Méditerranée, 13009 Marseille, France
| | - Vincent Villette
- 1 Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France 2 Aix-Marseille Université, Unité Mixte de Recherche S901, 13009 Marseille, France 3 Institut de Neurobiologie de la Méditerranée, 13009 Marseille, France
| | - Thomas Tressard
- 1 Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France 2 Aix-Marseille Université, Unité Mixte de Recherche S901, 13009 Marseille, France 3 Institut de Neurobiologie de la Méditerranée, 13009 Marseille, France
| | - Arnaud Malvache
- 1 Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France 2 Aix-Marseille Université, Unité Mixte de Recherche S901, 13009 Marseille, France 3 Institut de Neurobiologie de la Méditerranée, 13009 Marseille, France
| | - Susanne Reichinnek
- 1 Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France 2 Aix-Marseille Université, Unité Mixte de Recherche S901, 13009 Marseille, France 3 Institut de Neurobiologie de la Méditerranée, 13009 Marseille, France
| | - Fabrice Bartolomei
- 4 Institut des Neurosciences des Systèmes, Institut National de la Santé et de la Recherche Médicale Unité 1106, 13005 Marseille, France
| | - Rosa Cossart
- 1 Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France 2 Aix-Marseille Université, Unité Mixte de Recherche S901, 13009 Marseille, France 3 Institut de Neurobiologie de la Méditerranée, 13009 Marseille, France
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Brna P, Duchowny M, Resnick T, Dunoyer C, Bhatia S, Jayakar P. The diagnostic utility of intracranial EEG monitoring for epilepsy surgery in children. Epilepsia 2015; 56:1065-70. [DOI: 10.1111/epi.12983] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Paula Brna
- IWK Health Centre; Dalhousie University; Halifax Nova Scotia Canada
| | - Michael Duchowny
- Brain Institute; Miami Children's Hospital; Miami Florida U.S.A
- Department of Neurology; Miami Children's Hospital; Miami Florida U.S.A
| | - Trevor Resnick
- Brain Institute; Miami Children's Hospital; Miami Florida U.S.A
- Department of Neurology; Miami Children's Hospital; Miami Florida U.S.A
| | | | - Sanjiv Bhatia
- Brain Institute; Miami Children's Hospital; Miami Florida U.S.A
- Division of Neurosurgery; Miami Children's Hospital; Miami Florida U.S.A
| | - Prasanna Jayakar
- Brain Institute; Miami Children's Hospital; Miami Florida U.S.A
- Department of Neurology; Miami Children's Hospital; Miami Florida U.S.A
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Kowski AB, Holtkamp M. Electrically induced limbic seizures: preliminary findings in a rodent model. J Exp Neurosci 2015; 9:7-14. [PMID: 25861223 PMCID: PMC4376203 DOI: 10.4137/jen.s23759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 02/03/2015] [Accepted: 02/05/2015] [Indexed: 11/05/2022] Open
Abstract
In epilepsy, novel pharmacological and nonpharmacological treatment approaches are commonly assessed in model systems of acute motor and often generalized seizures. We developed a rodent model with short-term electrical stimulation of the perforant path resulting in stereotyped limbic seizures. Limbic structures play a major role in human intractable epilepsy. In 10 rats, single electrical 5-second and 20-Hz stimuli to the perforant path reliably produced limbic seizures characterized by resting behavior and subtle motor signs. Electrophysiological recordings from the dentate gyrus demonstrated a seizure pattern with 4-Hz to 5-Hz discharges. Multiple inductions of seizures within 72 hours did not alter behavioral and electrophysiological seizure characteristics. Electrophysiological excitatory and inhibitory parameters assessed by evoked single and paired pulses did not change with increasing number of seizures. We present preliminary findings on a new model of electrically induced limbic seizures of mesiotemporal origin. This model may represent a reliable screening tool for new treatment approaches such as deep brain stimulation.
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Affiliation(s)
- Alexander B Kowski
- Department of Neurology, Epilepsy-Center Berlin-Brandenburg, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Martin Holtkamp
- Department of Neurology, Epilepsy-Center Berlin-Brandenburg, Charité-Universitätsmedizin Berlin, Berlin, Germany
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A History of the Epilepsy Programme at University Hospital (LHSC) & Western University, London, Ontario Canada 1975- 2012. Can J Neurol Sci 2014. [DOI: 10.1017/s0317167100018096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Mani J. Video electroencephalogram telemetry in temporal lobe epilepsy. Ann Indian Acad Neurol 2014; 17:S45-9. [PMID: 24791089 PMCID: PMC4001214 DOI: 10.4103/0972-2327.128653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/02/2013] [Accepted: 10/02/2013] [Indexed: 11/15/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is the most commonly encountered medically refractory epilepsy. It is also the substrate of refractory epilepsy that gives the most gratifying results in any epilepsy surgery program, with a minimum use of resources. Correlation of clinical behavior and the ictal patterns during ictal behavior is mandatory for success at epilepsy surgery. Video electroencephalogram (EEG) telemetry achieves this goal and hence plays a pivotal role in pre-surgical assessment. The role of telemetry is continuously evolving with the advent of digital EEG technology, of high-resolution volumetric magnetic resonance imaging and other functional imaging techniques. Most of surgical selection in patients with TLE can be done with a scalp video EEG monitoring. However, the limitations of the scalp EEG technique demand invasive recordings in a selected group of TLE patients. This subset of the patients can be a challenge to the epileptologist.
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Affiliation(s)
- Jayanti Mani
- Department of Brain and Nervous System, Kokilaben Dhirubhai Ambani Hospital, Andheri West, Mumbai, Maharashtra, India, Department of Medicine Lokmanya Tilak Memorial Medical College and Municipal Hospital, Mumbai, Maharashtra, India
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Valentín A, Alarcón G, Barrington SF, García Seoane JJ, Martín-Miguel MC, Selway RP, Koutroumanidis M. Interictal estimation of intracranial seizure onset in temporal lobe epilepsy. Clin Neurophysiol 2014; 125:231-8. [DOI: 10.1016/j.clinph.2013.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 06/06/2013] [Accepted: 07/11/2013] [Indexed: 01/01/2023]
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Shen CP, Liu ST, Zhou WZ, Lin FS, Lam AYY, Sung HY, Chen W, Lin JW, Chiu MJ, Pan MK, Kao JH, Wu JM, Lai F. A physiology-based seizure detection system for multichannel EEG. PLoS One 2013; 8:e65862. [PMID: 23799053 PMCID: PMC3683026 DOI: 10.1371/journal.pone.0065862] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 04/29/2013] [Indexed: 11/22/2022] Open
Abstract
Background Epilepsy is a common chronic neurological disorder characterized by recurrent unprovoked seizures. Electroencephalogram (EEG) signals play a critical role in the diagnosis of epilepsy. Multichannel EEGs contain more information than do single-channel EEGs. Automatic detection algorithms for spikes or seizures have traditionally been implemented on single-channel EEG, and algorithms for multichannel EEG are unavailable. Methodology This study proposes a physiology-based detection system for epileptic seizures that uses multichannel EEG signals. The proposed technique was tested on two EEG data sets acquired from 18 patients. Both unipolar and bipolar EEG signals were analyzed. We employed sample entropy (SampEn), statistical values, and concepts used in clinical neurophysiology (e.g., phase reversals and potential fields of a bipolar EEG) to extract the features. We further tested the performance of a genetic algorithm cascaded with a support vector machine and post-classification spike matching. Principal Findings We obtained 86.69% spike detection and 99.77% seizure detection for Data Set I. The detection system was further validated using the model trained by Data Set I on Data Set II. The system again showed high performance, with 91.18% detection of spikes and 99.22% seizure detection. Conclusion We report a de novo EEG classification system for seizure and spike detection on multichannel EEG that includes physiology-based knowledge to enhance the performance of this type of system.
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Affiliation(s)
- Chia-Ping Shen
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Shih-Ting Liu
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Wei-Zhi Zhou
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Feng-Seng Lin
- Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan
| | - Andy Yan-Yu Lam
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Hsiao-Ya Sung
- Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan
| | - Wei Chen
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Jeng-Wei Lin
- Department of Information Management, Tunghai University, Tai-Chung, Taiwan
| | - Ming-Jang Chiu
- Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan
- Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan
- * E-mail:
| | - Ming-Kai Pan
- Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan
- Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan
| | - Jui-Hung Kao
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Jin-Ming Wu
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Feipei Lai
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
- Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan
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Blume WT. Slowly evolving trends in temporal lobe epilepsy management at london health sciences centre. EPILEPSY RESEARCH AND TREATMENT 2013; 2013:387510. [PMID: 23533736 PMCID: PMC3596901 DOI: 10.1155/2013/387510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 06/15/2012] [Indexed: 11/17/2022]
Abstract
Although the advent of MRI impacted significantly our presurgical investigation, ictal semiology with interictal and ictal EEG has clearly retained its roles in localizing epileptogenesis. MRI-identified lesions considered epileptogenic on semiological and electroencephalographic grounds have increased the likelihood of resective surgery effectiveness whereas a nonlesional MRI would diminish this probability. Ictal propagation and the interplay between its source and destination have emerged as a significant component of seizure evaluation over the past 30 years.
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Affiliation(s)
- Warren T. Blume
- London Health Sciences Centre, Western University, London, ON, Canada N6A 5A5
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18
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Raghavendra S, Nooraine J, Mirsattari SM. Role of electroencephalography in presurgical evaluation of temporal lobe epilepsy. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:204693. [PMID: 23198144 PMCID: PMC3503287 DOI: 10.1155/2012/204693] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 01/18/2012] [Accepted: 06/28/2012] [Indexed: 11/17/2022]
Abstract
Surgery remains a therapeutic option for patients with medically refractory epilepsy. Comprehensive presurgical evaluation includes electroencephalography (EEG) and video EEG in identifying patients who are likely to benefit from surgery. Here, we discuss in detail the utility of EEG in presurgical evaluation of patients with temporal lobe epilepsy along with illustrative cases.
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Affiliation(s)
| | - Javeria Nooraine
- Department of Neurology, Vikram Hospital, Bangalore 560052, India
| | - Seyed M. Mirsattari
- Departments of Clinical Neurological Sciences, Medical Imaging, Medical Biophysics, and Psychology, University of Western Ontario, London, ON, Canada N6A 5A5
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19
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Ákos P, Thalhammer J, Leschnik M, Halász P. Electroencephalographic examination of epileptic dogs under propofol restraint. Acta Vet Hung 2012; 60:309-24. [PMID: 22903076 DOI: 10.1556/avet.2012.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The main aim of this study was to identify interictal epileptiform discharges in a group of dogs with seizures of known aetiology (symptomatic epilepsy, SE) and in dogs with idiopathic epilepsy (IE). Propofol was used for chemical restraint in all dogs. We found electroencephalographic (EEG) changes that could be considered epileptiform discharges (EDs) in 5 out of 40 dogs (12.5%). The EEG changes identified were spikes in four cases and periodic epileptiform discharges in one case. All EDs were seen in the SE group. We conclude that the interictal electroencephalographic examinations of propofolanaesthetised dogs suffering from IE and SE rarely show epileptic discharges and that the diagnostic value of such EEGs in the work-up for epilepsy seems to be low as epileptic discharges were unlikely to be detected. However, positive findings are more likely to be connected with SE. We found frequent, transient EEG phenomena (spindles, K-complexes, vertex waves, positive occipital sharp transients of sleep, cyclic alternating patterns), which are non-epileptic but their differentiation from epileptic phenomena is challenging.
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Affiliation(s)
- Pákozdy Ákos
- 1 University of Veterinary Medicine Clinic for Internal Medicine for Small Animals A-1210 Veterinärplatz 1 Vienna Austria
| | - Johann Thalhammer
- 1 University of Veterinary Medicine Clinic for Internal Medicine for Small Animals A-1210 Veterinärplatz 1 Vienna Austria
| | - Michael Leschnik
- 1 University of Veterinary Medicine Clinic for Internal Medicine for Small Animals A-1210 Veterinärplatz 1 Vienna Austria
| | - Péter Halász
- 2 Institute of Experimental Medicine Budapest Hungary
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20
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Bercovici E, Kumar BS, Mirsattari SM. Neocortical temporal lobe epilepsy. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:103160. [PMID: 22953057 PMCID: PMC3420667 DOI: 10.1155/2012/103160] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 01/04/2012] [Accepted: 05/22/2012] [Indexed: 01/15/2023]
Abstract
Complex partial seizures (CPSs) can present with various semiologies, while mesial temporal lobe epilepsy (mTLE) is a well-recognized cause of CPS, neocortical temporal lobe epilepsy (nTLE) albeit being less common is increasingly recognized as separate disease entity. Differentiating the two remains a challenge for epileptologists as many symptoms overlap due to reciprocal connections between the neocortical and the mesial temporal regions. Various studies have attempted to correctly localize the seizure focus in nTLE as patients with this disorder may benefit from surgery. While earlier work predicted poor outcomes in this population, recent work challenges those ideas yielding good outcomes in part due to better localization using improved anatomical and functional techniques. This paper provides a comprehensive review of the diagnostic workup, particularly the application of recent advances in electroencephalography and functional brain imaging, in neocortical temporal lobe epilepsy.
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Affiliation(s)
- Eduard Bercovici
- Division of Neurology, University of Toronto, Toronto, ON, Canada
| | - Balagobal Santosh Kumar
- Department of Clinical Neurological Sciences, University of Western Ontario, London, ON, Canada
| | - Seyed M. Mirsattari
- Department of Clinical Neurological Sciences, University of Western Ontario, London, ON, Canada
- Department of Medical Imaging, University of Western Ontario, London, ON, Canada
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
- Department of Psychology, University of Western Ontario, London, ON, Canada
- London Health Sciences Centre, B10-110, London, ON, Canada N6A 5A5
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Badawy RAB, Johnson KA, Cook MJ, Harvey AS. A mechanistic appraisal of cognitive dysfunction in epilepsy. Neurosci Biobehav Rev 2012; 36:1885-96. [PMID: 22617705 DOI: 10.1016/j.neubiorev.2012.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 03/24/2012] [Accepted: 05/13/2012] [Indexed: 12/14/2022]
Abstract
A strong relationship between the clinical characteristics of epilepsy and the nature of cognitive impairments associated with the condition has been found, but the nature of this relationship appears to be quite complex and not well understood. This review presents a summary of the research on the interaction between cognition and epilepsy, surveyed from a mechanistic perspective with the aim of clarifying factors that contribute to the co-existence of both disorders. The physiological basis underpinning cognitive processing is first reviewed. The physiology of epilepsy is reviewed, with emphasis placed on interictal discharges and seizures. The nature of the impact of epilepsy on cognition is described, with transient and prolonged effects distinguished. Finally, the complexity of the co-morbidity between cognitive dysfunction and epilepsy is discussed in relation to childhood and adult-onset epilepsy syndromes and severe epileptic encephalopathies. Structural and functional abnormalities exist in patients with epilepsy that may underpin both the cognitive dysfunction and epilepsy, highlighting the complexity of the association. Research, possibly of a longitudinal nature, is needed to elucidate this multifactorial relationship between cognitive dysfunction and epilepsy.
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Affiliation(s)
- Radwa A B Badawy
- Department of Clinical Neurosciences, St. Vincent's Hospital, Melbourne, Victoria, Australia; Department of Medicine, Melbourne, Victoria, Australia; Electrical and Electronic Engineering, Melbourne, Victoria, Australia. ,
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Negishi M, Martuzzi R, Novotny EJ, Spencer DD, Constable RT. Functional MRI connectivity as a predictor of the surgical outcome of epilepsy. Epilepsia 2011; 52:1733-40. [PMID: 21801165 DOI: 10.1111/j.1528-1167.2011.03191.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE In planning epilepsy surgery, it is important to be able to assess the likelihood of success of surgery for each patient so that the possible risk and benefit can be properly considered. In this study, functional connectivity was investigated as a means for predicting surgical outcome from the preoperative functional magnetic resonance imaging (fMRI) of epilepsy patients. METHODS Resting-state simultaneous electroencephalography (EEG)-fMRI data were collected from 18 patients with intractable epilepsy before surgery and from 14 healthy subjects. For each patient, EEG-spike correlated fMRI analysis was performed and an activation cluster that overlapped the most with the planned resection area for each patient was chosen as the seed for the functional connectivity analysis. After the functional connectivity maps were computed, laterality indices of functional connectivity were contrasted between patients who had seizures after surgeries (seizure-recurrence group) and those who did not have them for at least a year (seizure-free group). KEY FINDINGS Patients in the seizure-recurrence group had less-lateralized functional connectivity than patients in the seizure-free group (t(16) = 2.3, after control subtracted and Fisher transformed, p < 0.05, two-tailed). SIGNIFICANCE This study suggests the potential for using preoperative fMRI connectivity analysis as a predictive outcome measure. If confirmed by further research, a high laterality will be an important addition to the other predictors of better surgical outcome such as febrile seizures, mesial temporal sclerosis, tumors, abnormal MRI, and EEG/MRI concordance.
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Affiliation(s)
- Michiro Negishi
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520-8043, USA.
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23
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Extent of EEG epileptiform pattern distribution in "focal" cortical dysplasia. J Clin Neurophysiol 2011; 27:309-11. [PMID: 20844446 DOI: 10.1097/wnp.0b013e3181f38693] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
To assess the pathophysiological complexity of cortical dysplasia-related intractable focal epilepsy among surgical candidates, using our data-based EEG classification system, we reviewed preresection scalp awake and sleep EEGs (median, 8) in 46 consecutive patients whose resected pathology disclosed cortical dysplasia. Epileptiform phenomena occurred on at least one EEG in 42 (91%) patients. Twenty-three (50%) of the 46 patients displayed at least one type of independently occurring abnormality (spikes, excess delta, or theta) in each hemisphere. Nineteen of these 23 (83%), thus 41% of all 46 patients, showed independently occurring epileptiform abnormalities (spikes) in each hemisphere, i.e., the multiple independent spike foci phenomenon. In an additional 13 of the 46 (28%) patients, spike foci involving more than one lobe appeared within a single hemisphere. Thus, spike foci involving more than one lobe appeared in 32 of the 46 (70%) patients. Generalized bilaterally synchronous epileptiform features (spike waves, slow spike waves, or fast rhythmic waves) appeared in 10 (22%) of the 46 patients. Two findings suggest more widespread dysfunction among extratemporal patients than temporal patients: (1) a significantly higher number of lobes containing focal interictal epileptiform activity in extra temporal patients (mean = 3.14) than among temporal patients (mean = 2.14) (P = 0.02), (2) a higher percentage of bisynchronous epileptiform abnormalities: 8 of 23 (35%) versus 2 of 23 (9%). Among 34 patients with a Principal Spike Lobe (more active spiking over more EEGs), those of 32 (94%) arose from the ultimately resected lobe. Of the 30 patients with scalp-recorded seizures, relationship between seizure origin and ultimately resected lobe were same lobe (16 patients), same and adjacent lobes (12), adjacent lobe only (1), and distant lobe (1). Thus, despite the multifocality of several EEG features, Principal Spike Lobe and scalp-recorded seizure origin correlate well with epileptogenesis.
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Keller CJ, Truccolo W, Gale JT, Eskandar E, Thesen T, Carlson C, Devinsky O, Kuzniecky R, Doyle WK, Madsen JR, Schomer DL, Mehta AD, Brown EN, Hochberg LR, Ulbert I, Halgren E, Cash SS. Heterogeneous neuronal firing patterns during interictal epileptiform discharges in the human cortex. ACTA ACUST UNITED AC 2010; 133:1668-81. [PMID: 20511283 DOI: 10.1093/brain/awq112] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Epileptic cortex is characterized by paroxysmal electrical discharges. Analysis of these interictal discharges typically manifests as spike-wave complexes on electroencephalography, and plays a critical role in diagnosing and treating epilepsy. Despite their fundamental importance, little is known about the neurophysiological mechanisms generating these events in human focal epilepsy. Using three different systems of microelectrodes, we recorded local field potentials and single-unit action potentials during interictal discharges in patients with medically intractable focal epilepsy undergoing diagnostic workup for localization of seizure foci. We studied 336 single units in 20 patients. Ten different cortical areas and the hippocampus, including regions both inside and outside the seizure focus, were sampled. In three of these patients, high density microelectrode arrays simultaneously recorded between 43 and 166 single units from a small (4 mm x 4 mm) patch of cortex. We examined how the firing rates of individual neurons changed during interictal discharges by determining whether the firing rate during the event was the same, above or below a median baseline firing rate estimated from interictal discharge-free periods (Kruskal-Wallis one-way analysis, P<0.05). Only 48% of the recorded units showed such a modulation in firing rate within 500 ms of the discharge. Units modulated during the discharge exhibited significantly higher baseline firing and bursting rates than unmodulated units. As expected, many units (27% of the modulated population) showed an increase in firing rate during the fast segment of the discharge (+ or - 35 ms from the peak of the discharge), while 50% showed a decrease during the slow wave. Notably, in direct contrast to predictions based on models of a pure paroxysmal depolarizing shift, 7.7% of modulated units recorded in or near the seizure focus showed a decrease in activity well ahead (0-300 ms) of the discharge onset, while 12.2% of units increased in activity in this period. No such pre-discharge changes were seen in regions well outside the seizure focus. In many recordings there was also a decrease in broadband field potential activity during this same pre-discharge period. The different patterns of interictal discharge-modulated firing were classified into more than 15 different categories. This heterogeneity in single unit activity was present within small cortical regions as well as inside and outside the seizure onset zone, suggesting that interictal epileptiform activity in patients with epilepsy is not a simple paroxysm of hypersynchronous excitatory activity, but rather represents an interplay of multiple distinct neuronal types within complex neuronal networks.
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Affiliation(s)
- Corey J Keller
- Department of Neurology, 30 Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
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Jaseja H. Vagal nerve stimulation: exploring its efficacy and success for an improved prognosis and quality of life in cerebral palsy patients. Clin Neurol Neurosurg 2008; 110:755-62. [PMID: 18572305 DOI: 10.1016/j.clineuro.2008.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2007] [Revised: 04/29/2008] [Accepted: 05/09/2008] [Indexed: 02/08/2023]
Abstract
Cerebral palsy (CP) continues to pose a cause for major socioeconomic concern and medical challenge worldwide. It is associated with a multi-faceted symptomatology warranting a multi-dimensional management-approach. Recent recognition of neurocognitive impairment and its hopefully possible treatment has opened up a new dimension in its management to the neurologists. Vagal nerve stimulation (VNS) technique is presently emerging as an effective alternative anti-epileptic therapeutic measure in intractable epilepsy. VNS has recently been shown to possess a suppressive effect also on interictal epileptiform discharges (IEDs) that are now being widely accepted as established associates of neurocognitive impairment. In this paper, the author proposes VNS technique implantation in CP patients on account of its dual therapeutic effectiveness, i.e. anti-epileptic and IED-suppression. These two effects are likely to control seizures that are quite often drug-resistant and also improve neurocognition in CP patients, thus hoping for a better overall prognostic outcome and an improved quality of life of the CP patients by VNS.
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Affiliation(s)
- Harinder Jaseja
- Physiology Department, G.R. Medical College, Gwalior 474001, MP, India.
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26
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Zijlmans M, Huiskamp GM, van Huffelen AC, Spetgens WP, Leijten FS. Detection of temporal lobe spikes: Comparing nasopharyngeal, cheek and anterior temporal electrodes to simultaneous subdural recordings. Clin Neurophysiol 2008; 119:1771-1777. [DOI: 10.1016/j.clinph.2008.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2007] [Revised: 04/09/2008] [Accepted: 04/10/2008] [Indexed: 10/22/2022]
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Tao JX, Baldwin M, Ray A, Hawes-Ebersole S, Ebersole JS. The Impact of Cerebral Source Area and Synchrony on Recording Scalp Electroencephalography Ictal Patterns. Epilepsia 2007; 48:2167-76. [PMID: 17662060 DOI: 10.1111/j.1528-1167.2007.01224.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
PURPOSE To determine the cerebral electroencephalography (EEG) substrates of scalp EEG seizure patterns, such as source area and synchrony, and in so doing assess the limitations of scalp seizure recording in the localization of seizure onset zones in patients with temporal lobe epilepsy. METHODS We recorded simultaneously 26 channels of scalp EEG with subtemporal supplementary electrodes and 46-98 channels of intracranial EEG in presurgical candidates with temporal lobe epilepsy. We correlated intracranial EEG source area and synchrony at seizure onset with the corresponding scalp EEG. Eighty-six simultaneous intracranial- and scalp-recorded seizures from 23 patients were evaluated. RESULTS Thirty-four intracranial ictal discharges (40%) from 9 patients (39%) had sufficient cortical source area (namely > 10 cm(2)) and synchrony at seizure onset to produce a simultaneous or nearly simultaneous focal scalp EEG ictal pattern. Forty-one intracranial ictal discharges (48%) from 10 patients (43%) gradually achieved the necessary source area and synchrony over several seconds to generate a scalp EEG ictal pattern. These scalp rhythms were lateralized, but not localizable as to seizure origin. Eleven intracranial ictal discharges (13%) from 4 patients (17%) recruited the necessary source area, but lacked sufficient synchrony to result in a clearly localized or lateralized scalp ictal pattern. CONCLUSIONS Sufficient source area and synchrony are mandatory cerebral EEG requirements for generating scalp-recordable ictal EEG patterns. The dynamic interaction of cortical source area and synchrony at the onset and during a seizure is a primary reason for heterogeneous scalp ictal EEG patterns.
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Affiliation(s)
- James X Tao
- Adult Epilepsy Service, Department of Neurology, The University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, U.S.A.
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Jaseja H. Treatment of interictal epileptiform discharges in cerebral palsy patients without clinical epilepsy: hope for a better outcome in prognosis. Clin Neurol Neurosurg 2007; 109:221-4. [PMID: 17157435 DOI: 10.1016/j.clineuro.2006.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Revised: 11/10/2006] [Accepted: 11/14/2006] [Indexed: 02/05/2023]
Abstract
Cerebral palsy (CP) is a motor disorder due to cerebral damage. It is commonly associated with neuro-psychological retardation and also with epilepsy; hence, its management warrants a multi-dimensional approach. In a significant number of CP patients, interictal epileptiform discharges (IEDs) are obtained in their EEG even in absence of clinical epilepsy. Epileptiform discharge-firing cortical neurons are found to be associated with elevated intracellular Ca(2+) levels and exhibition of abnormal response on exposure to excitotoxic glutamate; both these features have been found to lead to subsequent death of these neurons. This further damage is likely to aggravate the already existing cortical damage in CP patients thereby worsening their prognosis. IEDs are also known to be associated with other neuro-psychological disorders like cognitive impairment and behavioral problems even in absence of clinical epilepsy. Thus, the IEDs cannot be viewed as benign events and their occurrence even in absence of clinical epilepsy cannot be ignored. A few trials aimed at treating IEDs in autistic patients without epilepsy and in children with behavior problems have yielded favorable results. Based on these studies, the author proposes inclusion of EEG investigation in the management protocol of CP patients and treatment of IEDs (when detected even in absence of clinical epilepsy) for a better outcome in their prognosis.
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Affiliation(s)
- Harinder Jaseja
- Physiology Department, G.R. Medical College, Gwalior 474001, Madhya Pradesh, India.
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Koukou A, Dupont S, Szurhaj W, Baulac M, Derambure P, Adam C. Complete change of seizure and spike lateralization in temporal lobe epilepsy at two separate monitorings. Clin Neurophysiol 2007; 118:255-61. [PMID: 17141566 DOI: 10.1016/j.clinph.2006.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 09/26/2006] [Accepted: 10/03/2006] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To report complete change of seizure and spike lateralization over time in bilateral temporal lobe epilepsies (TLE). METHODS Repetition of video-EEG monitorings in 115 patients; 2 cases are reported in detail; 113 other severe partial epilepsies were included to estimate retrospectively the frequency of the reported phenomenon. RESULTS In 2 cases, two video-EEG monitorings, separated by several months, revealed the first time one unilateral TL (temporal lobe) seizure and spike focus and the second time a distinct seizure and spike focus located in the opposite TL. The second monitoring was planned for these two patients because of the presence of a discordant lesion or, in the absence of a lesion, of some bilateral or discordant functional (EEG, SPECT and PET) abnormalities. No patient among the other 113 cases had this video-EEG pattern. CONCLUSIONS In TLE, two video-EEG sessions may be necessary to disclose two opposite TL epileptogenic foci. SIGNIFICANCE In rare bilateral TLE cases, the expression of seizure and spike foci can alternate between hemispheres.
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Affiliation(s)
- Areti Koukou
- AP-HP, Epileptology Unit, Hôpital de La Pitié-Salpêtrière, Service de Neurologie 1, Hôpital de La Pitié-Salpêtrière 47-83 Bd de 1'Hôpital 75651, Paris Cedex 13, France
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Ray A, Tao JX, Hawes-Ebersole SM, Ebersole JS. Localizing value of scalp EEG spikes: A simultaneous scalp and intracranial study. Clin Neurophysiol 2007; 118:69-79. [PMID: 17126071 DOI: 10.1016/j.clinph.2006.09.010] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Revised: 09/09/2006] [Accepted: 09/17/2006] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To determine the relationship between cortical origins of interictal and ictal EEG discharges in patients with temporal lobe epilepsy. METHODS Simultaneous cortical and scalp EEG recordings were obtained from six patients with temporal lobe epilepsy. Subdural electrode contacts active at seizure onset and when scalp ictal rhythms became evident were identified. Similarly, cortical substrates of scalp EEG spikes were identified at spike peak and at the initial rising phase of the potential. RESULTS Intracranial seizure onsets were commonly focal and involved only a few electrode contacts, as opposed to scalp ictal rhythms, which required synchronous activation of multiple electrode contacts. At the peak of scalp spikes, multiple electrode contacts were similarly active. However, at spike onset, cortical substrates were more discrete and commonly involved electrodes similar to that of seizure onsets. CONCLUSIONS Scalp EEG ictal rhythms and the peak of a scalp spike may poorly localize the epileptogenic focus because of propagation. Cortical source area at scalp spike onset is more discrete, however, and the seizure onset zone often lies within this area. SIGNIFICANCE Analysis of scalp spikes, such as source modeling, at their initial rising phase might provide useful localizing information about seizure origins in the same patient.
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Affiliation(s)
- Amit Ray
- Department of Neurology, Section of Epilepsy, Cleveland Clinic Foundation, Cleveland, OH, USA.
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Gaggero R, Haupt R, Paola Fondelli M, De Vescovi R, Marino A, Lanino E, Dallorso S, Faraci M. Intractable epilepsy secondary to cyclosporine toxicity in children undergoing allogeneic hematopoietic bone marrow transplantation. J Child Neurol 2006; 21:861-6. [PMID: 17005102 DOI: 10.1177/08830738060210100501] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The long-term evolution to intractable epilepsy in children treated with cyclosporine administered for graft-versus-host-disease after hematopoietic stem cell transplantation was evaluated. In a group of 185 children treated with cyclosporine after bone marrow transplantation, 15 (8%) presented with acute seizures that were generalized in 7 and focal in 7 and had absence status in 1. Electroencephalography (EEG) and neuroimaging showed predominant abnormalities in the occipital regions. One patient died shortly after the seizure; in seven cases, seizures remitted, whereas relapses were observed in seven others. After the first year, seizures persisted chronically in four cases and evolved to intractable epilepsy. Focal temporal epilepsy was diagnosed in three cases, whereas in the fourth case, a multifocal epilepsy was observed. Magnetic resonance imaging (MRI) detected mesial temporal sclerosis in all of these cases. The risk factors associated with evolution to epilepsy included lower age at transplantation (3-5 years), more than one relapsing seizure in the first year after transplantation, and longer treatment with cyclosporine. Not only can cyclosporine cause acute central nervous system toxicity, it can also determine intractable epilepsy associated with mesial temporal sclerosis.
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Affiliation(s)
- Roberto Gaggero
- Child Neurology Department, Gaslini Children's Research Institute, Genova, Italy.
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Abstract
PURPOSE To determine the area of cortical generators of scalp EEG interictal spikes, such as those in the temporal lobe epilepsy. METHODS We recorded simultaneously 26 channels of scalp EEG with subtemporal supplementary electrodes and 46 to 98 channels of intracranial EEG in 16 surgery candidates with temporal lobe epilepsy. Cerebral discharges with and without scalp EEG correlates were identified, and the area of cortical sources was estimated from the number of electrode contacts demonstrating concurrent depolarization. RESULTS We reviewed approximately 600 interictal spikes recorded with intracranial EEG. Only a very few of these cortical spikes were associated with scalp recognizable potentials; 90% of cortical spikes with a source area of >10 cm(2) produced scalp EEG spikes, whereas only 10% of cortical spikes having <10 cm(2) of source area produced scalp potentials. Intracranial spikes with <6 cm(2) of area were never associated with scalp EEG spikes. CONCLUSIONS Cerebral sources of scalp EEG spikes are larger than commonly thought. Synchronous or at least temporally overlapping activation of 10-20 cm(2) of gyral cortex is common. The attenuating property of the skull may actually serve a useful role in filtering out all but the most significant interictal discharges that can recruit substantial surrounding cortex.
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Affiliation(s)
- James X Tao
- Department of Neurology, Adult Epilepsy Center, University of Chicago, Illinois 60637, USA.
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Abstract
This study compares ictal semiology, neurological examination and scalp EEG between lateral and mesial occipital epilepsy to assess the contribution non-invasive data make in determining the epileptogenic region within an occipital lobe. We assessed seizure origin in 41 occipital patients as lateral (11 patients), mesial (20) and both surfaces (10) as indicated by subdurally recorded seizures (nine), a lesion whose removal reduced seizure quantity by > or =90% (six), or who met both criteria (26). No aspect of semiology distinguished lateral from mesially originating occipital seizures. A pre-operative visual field deficit appeared in eight (42%) out of 19 testable patients with mesial originating seizures, three (30%) out of 10 patients with both surfaces epileptogenic, but none of the 10 testable patients whose seizures arose only from the lateral surface (P = 0.0373, lateral versus mesial and both surfaces). Although occipital seizures appeared on the majority of the first five scalp EEG recordings in four (36%) out of 11 patients with laterally originating occipital seizures compared with none of 20 patients in whom seizures originated mesially (P = 0.0105), no other scalp EEG feature distinguished seizures from these surfaces. We conclude that subdural electroencephalography is likely to be necessary to delineate the epileptogenic region within an occipital lobe. Nonetheless, focally originating scalp-recorded seizures accurately lateralized the epileptogenic zone in 20 (49%) of our 41 patients compared with only one (2%) which originated contralaterally (P = 0.0001). This relationship held when considering only the first five scalp EEGs: the seizures of 10 patients (24%) appeared ipsilaterally and none contralaterally (P = 0.001). Moreover, interictal occipital (01,2) and posterior temporal (T5, T6) spikes appeared consistently and significantly (P < 0.001) more commonly ipsilateral to epileptogenesis than contralateral using multiple methods of analysis.
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Affiliation(s)
- Warren T Blume
- University Hospital, The University of Western Ontario, London, Ontario, Canada.
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Blume WT. The necessity for sphenoidal electrodes in the presurgical evaluation of temporal lobe epilepsy: con position. J Clin Neurophysiol 2004; 20:305-10. [PMID: 14701991 DOI: 10.1097/00004691-200309000-00002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This article reviews several lines of evidence that efface the requirement for sphenoidal leads in the EEG investigation of temporal lobe epilepsy. Mandibular notch or anterior temporal electrodes, each situated well within the anterior temporal spike field, detect interictal and ictal epileptiform phenomena virtually as well as do sphenoidal leads, provide consistent recording circumstances, do not require physician expertise for their placement, and create no discomfort. This article also cites many studies demonstrating the reliability of ictal semeiology and of MRI in lateralizing and localizing temporal epileptogenesis. Thus, EEG constitutes one element in a matrix of lateralizing data.
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Affiliation(s)
- Warren T Blume
- London Health Sciences Centre-University Campus, The University of Western Ontario, London, Ontario, Canada
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Worrell GA, Parish L, Cranstoun SD, Jonas R, Baltuch G, Litt B. High-frequency oscillations and seizure generation in neocortical epilepsy. Brain 2004; 127:1496-506. [PMID: 15155522 DOI: 10.1093/brain/awh149] [Citation(s) in RCA: 346] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Neocortical seizures are often poorly localized, explosive and widespread at onset, making them poorly amenable to epilepsy surgery in the absence of associated focal brain lesions. We describe, for the first time in an unselected group of patients with neocortical epilepsy, the finding that high-frequency (60-100 Hz) epileptiform oscillations are highly localized in the seizure onset zone, both before and temporally removed from seizure onset. These findings were observed in all six patients with neocortical epilepsy out of 23 consecutive patients implanted with intracranial electrodes for pre-surgical evaluation during the study period. The majority of seizures (62%) in these patients were anticipated by an increase in high-frequency activity in the 20 min prior to neocortical seizure onset. Contrary to observations in normal brain, high-frequency activity was strongly modulated by behavioural state, and was maximal during slow-wave sleep, which may explain the propensity for neocortical onset seizures to begin during sleep. These findings point to an important role for neuromodulatory circuits, probably involving the thalamus, in mechanisms underlying seizure generation in neocortical epilepsy. These findings demonstrate that high-frequency epileptiform oscillations may prove clinically useful in localizing the seizure onset zone in neocortical epilepsy, for identifying periods of increased probability of seizure onset, and in elucidating mechanisms underlying neocortical ictogenesis. Confirmation that prolonged bursts of high-frequency activity may predict focal onset neocortical seizures will require prospective validation on continuous, prolonged recordings in a larger number of patients. Importantly, the results show that the dynamic range utilized in current clinical practice for localization of epileptogenic brain largely ignores fundamental oscillations that are signatures of an epileptogenic brain. It may prove that many currently available clinical EEG systems and EEG analysis methods utilize a dynamic range that discards clinically important information.
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Affiliation(s)
- Greg A Worrell
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, USA.
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Blume WT, Ganapathy GR, Munoz D, Lee DH. Indices of resective surgery effectiveness for intractable nonlesional focal epilepsy. Epilepsia 2004; 45:46-53. [PMID: 14692907 DOI: 10.1111/j.0013-9580.2004.11203.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Among 70 patients with intractable focal epilepsy and no specific lesion, as determined by both MRI (magnetic resonance imaging) and histopathology, outcome after resective surgery was polarized: 26 (37%) became seizure free (SF), and 27 (39%) were not helped. Eighteen (42%) of 43 standard temporal resections rendered patients SF, somewhat more than eight (30%) of 27 other procedures. To seek reliable prognostic factors, the subsequent correlative data compared features of the 26 SF patients with those of the 27 not helped. Although ictal semiology guided the site of surgical resection, it and other aspects of seizure and neurologic history failed to predict surgical outcome. However, two aspects of preoperative scalp EEGs correlated with SF outcomes: (a) among 25 patients in whom >50% of clinical seizures arose from the later resected lobe and no other origins, 18 (72%) became SF compared with seven (28%) of 25 with other ictal profiles; (b) 13 (93%) of 14 temporal lobe patients whose interictal and ictal EEGs lacked features indicative of multifocal epileptogenesis became SF compared with five (33%) of 15 with such components. The considered need for subdural (SD) EEG reduced SF outcome from 18 (90%) of 20 patients without SD to eight (24%) of 33 with SD; this likely reflected an insufficient congruity of ictal semiology and interictal and ictal scalp EEG for localizing epileptogenesis. Within this SD group, >50% of clinical seizure origins from a later resected lobe increased SF outcome somewhat: from two (14%) of 14 without this attribute to six (40%) of 15 with it; 100% of such origins increased SF outcome from two (12%) of 16 to six (46%) of 13.
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Affiliation(s)
- Warren T Blume
- London Health Sciences Centre-University Campus, Epilepsy Unit, University of Western Ontario, London, Ontario, Canada
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