Reoperation for Refractory Epilepsy in Childhood

Abstract BACKGROUND: Reoperations account for >10% in pediatric epilepsy surgery cohorts, and they are especially relevant in young children with catastrophic epilepsy. OBJECTIVE: To determine surgical outcomes and their predictive factors in reoperations for refractory epilepsy in childhood. METHODS: We retrospectively analyzed presurgical findings, resections, and outcomes of 23 consecutive children who underwent reoperations from 2000 to 2011. RESULTS: Etiology included cortical dysplasia with/without glioneuronal tumor in 19 patients (83%), sole glioneuronal tumor in 2, and tuberous sclerosis and Rasmussen encephalitis in 1 each. The reasons for the failure of the initial surgery were functional considerations in 8 (35%), incorrect delineation of the epileptogenic zone in 8 (35%), and resection not performed as initially planned in 7 (30%) cases. Final procedures included 8 (35%) intralobar, 8 (35%) multilobar resections, and 7 (30%) hemispherotomies. Following reoperations, 14 (61%) patients were seizure free, 6 (26%) showed significant or worthwhile improvement, and 3 (13%) did not respond to surgery. Six of 8 patients who underwent the first resection before the age of 3 years, 6 of 8 whose first resection was limited by functional considerations, and all 7 with hemispherotomy as the final resection achieved seizure freedom after reoperation. CONCLUSION: Reoperation is particularly beneficial for selected children with refractory epilepsy associated with cortical dysplasia that did not respond to an initial limited and/or early resection but achieved seizure freedom after extensive procedures. When indicated, reoperation should be performed at the youngest possible age to profit from higher functional plasticity in compensating for neurological deficit.

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Epilepsy surgery failure in children: a quantitative and qualitative analysis

Journal of Neurosurgery Pediatrics ◽

10.3171/2014.7.peds13658 ◽

2014 ◽

Vol 14 (4) ◽

pp. 386-395 ◽

Cited By ~ 28

Author(s):

Dario J. Englot ◽

Seunggu J. Han ◽

John D. Rolston ◽

Michael E. Ivan ◽

Rachel A. Kuperman ◽

...

Keyword(s):

Epilepsy Surgery ◽

Epilepsy Syndrome ◽

Pediatric Epilepsy ◽

Seizure Outcome ◽

Seizure Freedom ◽

Mesial Temporal Sclerosis ◽

Epileptogenic Zone ◽

Factors Associated ◽

Resection Cavity ◽

Pediatric Epilepsy Surgery

Object Resection is a safe and effective treatment option for children with pharmacoresistant focal epilepsy, but some patients continue experience seizures after surgery. While most studies of pediatric epilepsy surgery focus on predictors of postoperative seizure outcome, these factors are often not modifiable, and the reasons for surgical failure may remain unclear. Methods The authors performed a retrospective cohort study of children and adolescents who received focal resective surgery for pharmacoresistant epilepsy. Both quantitative and qualitative analyses of factors associated with persistent postoperative seizures were conducted. Results Records were reviewed from 110 patients, ranging in age from 6 months to 19 years at the time of surgery, who underwent a total of 115 resections. At a mean 3.1-year follow-up, 76% of patients were free of disabling seizures (Engel Class I outcome). Seizure freedom was predicted by temporal lobe surgery compared with extratemporal resection, tumor or mesial temporal sclerosis compared with cortical dysplasia or other pathologies, and by a lower preoperative seizure frequency. Factors associated with persistent seizures (Engel Class II–IV outcome) included residual epileptogenic tissue adjacent to the resection cavity (40%), an additional epileptogenic zone distant from the resection cavity (32%), and the presence of a hemispheric epilepsy syndrome (28%). Conclusions While seizure outcomes in pediatric epilepsy surgery may be improved by the use of high-resolution neuroimaging and invasive electrographic studies, a more aggressive resection should be considered in certain patients, including hemispherectomy if a hemispheric epilepsy syndrome is suspected. Family counseling regarding treatment expectations is critical, and reoperation may be warranted in select cases.

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Robot-assisted stereoelectroencephalography in children

Journal of Neurosurgery Pediatrics ◽

10.3171/2018.7.peds18305 ◽

2019 ◽

Vol 23 (3) ◽

pp. 288-296 ◽

Cited By ~ 3

Author(s):

Robert A. McGovern ◽

Elia Pestana Knight ◽

Ajay Gupta ◽

Ahsan N. V. Moosa ◽

Elaine Wyllie ◽

...

Keyword(s):

Proportional Hazards Model ◽

Refractory Epilepsy ◽

Cox Proportional Hazards Model ◽

Older Age ◽

Hospital Length Of Stay ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Robot Assisted ◽

Resective Surgery ◽

Medically Refractory Epilepsy

OBJECTIVEThe goal in the study was to describe the clinical outcomes associated with robot-assisted stereoelectroencephalography (SEEG) in children.METHODSThe authors performed a retrospective, single-center study in consecutive children with medically refractory epilepsy who were undergoing robot-assisted SEEG. Kaplan-Meier survival analysis was used to calculate the probability of seizure freedom. Both univariate and multivariate methods were used to analyze the preoperative and operative factors associated with seizure freedom.RESULTSFifty-seven children underwent a total of 64 robot-assisted procedures. The patients’ mean age was 12 years, an average of 6.4 antiepileptic drugs (AEDs) per patient had failed prior to implantation, and in 56% of the patients the disease was considered nonlesional. On average, children had 12.4 electrodes placed per implantation, with an implantation time of 9.6 minutes per electrode and a 10-day postoperative stay. SEEG analysis yielded a definable epileptogenic zone in 51 (89%) patients; 42 (74%) patients underwent surgery, half of whom were seizure free at last follow-up, 19.6 months from resection. In a multivariate generalized linear model, resective surgery, older age, and shorter SEEG-related hospital length of stay were associated with seizure freedom. In a Cox proportional hazards model including only the children who underwent resective surgery, older age was the only significant factor associated with seizure freedom. Complications related to bleeding were the major contributors to morbidity. One patient (1.5%) had a symptomatic hemorrhage resulting in a permanent neurological deficit.CONCLUSIONSThe authors report one of the largest pediatric-specific SEEG series demonstrating that the modern surgical management of medically refractory epilepsy in children can lead to seizure freedom in many patients, while also highlighting the challenges posed by this difficult patient population.

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Depth Electrodes in Pediatric Epilepsy Surgery

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100012944 ◽

2013 ◽

Vol 40 (1) ◽

pp. 48-55 ◽

Cited By ~ 10

Author(s):

Janani Kassiri ◽

Jeff Pugh ◽

Sharon Carline ◽

Laura Jurasek ◽

Thomas Snyder ◽

...

Keyword(s):

Epilepsy Surgery ◽

Pediatric Epilepsy ◽

Surgical Removal ◽

Seizure Freedom ◽

Sufficient Information ◽

Epileptogenic Zone ◽

Depth Electrodes ◽

Depth Electrode ◽

Intractable Seizures ◽

Clinical Scenarios

Abstract:Background:The surgical removal of the epileptogenic zone in medically intractable seizures depends on accurate localization to minimize the neurological sequelae and prevent future seizures. To date, few studies have demonstrated the use of depth electrodes in a pediatric epilepsy population. Here, we report our study of pediatric epilepsy patients at our epilepsy center who were successfully operated for medically intractable seizures following the use of intracranial depth electrodes. In addition, we detail three individuals with distinct clinical scenarios in which depth electrodes were helpful and describe our technical approach to implantation and surgery.Methods:We retrospectively reviewed 18 pediatric epilepsy patients requiring depth electrode studies who presented at the University of Alberta Comprehensive Epilepsy Program between 1999 and 2010 with medically intractable epilepsy. Patients underwent cortical resection following depth electrode placement according to the Comprehensive Epilepsy Program surgical protocols after failure of surface electroencephalogram and magnetic resonance imaging to localize ictal onset zone.Result:The ictal onset zone was successfully identified in all 18 patients. Treatment of all surgical patients resulted in successful seizure freedom (Engel class I) without neurological complications.Conclusion:Intracranial depth electrode use is safe and able to provide sufficient information for the identification of the epileptogenic zone in pediatric epilepsy patients previously not considered for epilepsy surgery.

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Validating EEG, MEG and combined MEG and EEG beamforming for an estimation of the epileptogenic zone in focal cortical dysplasia

10.1101/2021.12.07.21267178 ◽

2021 ◽

Author(s):

Frank Neugebauer ◽

Marios Antonakakis ◽

Kanjana Unnwongse ◽

Yaroslav Parpaley ◽

Jörg Wellmer ◽

...

Keyword(s):

Regularization Parameter ◽

Focal Cortical Dysplasia ◽

Estimation Method ◽

Cortical Dysplasia ◽

Source Analysis ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Scanning Method ◽

Eeg Source Analysis ◽

Skull Conductivity

AbstractMEG and EEG source analysis is frequently used for the presurgical evaluation of pharma-coresistant epilepsy patients. The source localization of the epileptogenic zone depends, among other aspects, on the selected inverse and forward approaches and their respective parameter choices. In this validation study, we compare for the inverse problem the standard dipole scanning method with two beamformer approaches and we investigate the influence of the covariance estimation method and the strength of regularization on the localization performance for EEG, MEG and combined EEG and MEG. For forward modeling, we investigate the difference between calibrated six-compartment and standard three-compartment head modeling. In a retrospective study of two patients with focal epilepsy due to focal cortical dysplasia type IIb and seizure-freedom following lesionectomy or radiofrequency-guided thermocoagulation, we used the distance of the localization of interictal epileptic spikes to the resection cavity resp. rediofrequency lesion as reference for good localization. We found that beamformer localization can be sensitive to the choice of the regularization parameter, which has to be individually optimized. Estimation of the covariance matrix with averaged spike data yielded more robust results across the modalities. MEG was the dominant modality and provided a good localization in one case, while it was EEG for the other. When combining the modalities, the good results of the dominant modality were mostly not spoiled by the weaker modality. For appropriate regularization parameter choices, the beamformer localized better than the standard dipole scan. Compared to the importance of an appropriate regularization, the sensitivity of the localization to the head modeling was smaller, due to similar skull conductivity modeling and the fixed source space without orientation constraint.

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On The Use of Machine Learning Algorithms to Classify Focal Cortical Dysplasia on MRI

10.5753/sbcas.2021.16063 ◽

2021 ◽

Author(s):

João Guilherme Pereira ◽

Matheus de Freitas Oliveira Baffa ◽

Fabrício Henrique Simozo ◽

Luiz Otavio Murta Junior ◽

Joaquim Cezar Felipe

Keyword(s):

Deep Neural Network ◽

Surgical Intervention ◽

Refractory Epilepsy ◽

Focal Cortical Dysplasia ◽

Cortical Dysplasia ◽

Machine Learning Algorithms ◽

Textural Features ◽

Epileptogenic Zone ◽

Neural Network Classifier ◽

Multiple Classifiers

Refractory epilepsy is a condition characterized by epileptic seizure occurrence which cannot be controlled with antiepileptic drugs. This condition is associated with an excessive neuronal discharge produced by a group of neurons in a certain epileptogenic zone. Focal Cortical Dysplasia (FCD), usually found in these zones, was detected as one of the main causes of refractory epilepsy. In these cases, surgical intervention is necessary to minimize or eliminate the seizure occurrences. However, surgical treatment is only indicated in cases where there is complete certainty of the FCD. In order to assist neurosurgeons to detect precisely these regions, this paper aims to develop a classiﬁcation method to detect FCD on MRI based on morphological and textural features from a voxel-level perspective. Multiple classiﬁers were tested throughout the extracted features, the best results achieved an accuracy of 91.76% using a Deep Neural Network classiﬁer and 96.15% with J48 Decision Tree. The set of evaluating metrics showed that the results are promising.

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Pediatric Epilepsy Surgery in Focal and Generalized Epilepsy: Current Trends and Recent Advancements

Journal of Pediatric Epilepsy ◽

10.1055/s-0040-1722298 ◽

2021 ◽

Author(s):

William B. Harris ◽

H. Westley Phillips ◽

Aria Fallah ◽

Gary W. Mathern

Keyword(s):

Epilepsy Surgery ◽

Intractable Epilepsy ◽

Pediatric Epilepsy ◽

Seizure Freedom ◽

Surgical Interventions ◽

Current Trends ◽

Pediatric Epilepsy Surgery ◽

Generalized Epilepsy ◽

Epileptogenic Foci

AbstractFor a subset of children with medically intractable epilepsy, surgery may provide the best chances of seizure freedom. Whereas the indications for epilepsy surgery are commonly thought to be limited to patients with focal epileptogenic foci, modern imaging and surgical interventions frequently permit successful surgical treatment of generalized epilepsy. Resection continues to be the only potentially curative intervention; however, the advent of various neuromodulation interventions provides an effective palliative strategy for generalized or persistent seizures. Although the risks and benefits vary greatly by type and extent of intervention, the seizure outcomes appear to be uniformly favorable. Advances in both resective and nonresective surgical interventions provide promise for improved seizure freedom, function, and quality of life. This review summarizes the current trends and recent advancements in pediatric epilepsy surgery from diagnostic workup and indications through surgical interventions and postoperative outcomes.

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Neurons Recorded from Pediatric Epilepsy Surgery Patients with Cortical Dysplasia

Epilepsia ◽

10.1111/j.1528-1157.2000.tb01575.x ◽

2000 ◽

Vol 41 (s6) ◽

pp. S162-S167 ◽

Cited By ~ 48

Author(s):

Gary W. Mathern ◽

Carlos Cepeda ◽

Raymond S. Hurst ◽

Jorge Flores-Hernandez ◽

Delia Mendoza ◽

...

Keyword(s):

Epilepsy Surgery ◽

Cortical Dysplasia ◽

Pediatric Epilepsy ◽

Pediatric Epilepsy Surgery

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Cognitive Development in Pediatric Epilepsy Surgery

Neuropediatrics ◽

10.1055/s-0037-1609034 ◽

2017 ◽

Vol 49 (02) ◽

pp. 093-103 ◽

Cited By ~ 11

Author(s):

Gitta Reuner ◽

Georgia Ramantani

Keyword(s):

Cognitive Development ◽

Epilepsy Surgery ◽

Verbal Learning ◽

Pediatric Epilepsy ◽

Seizure Freedom ◽

Effective Treatment Option ◽

Multicenter Studies ◽

Assessment Protocol ◽

Pediatric Epilepsy Surgery ◽

Developmental Impairment

AbstractEpilepsy surgery is a very effective treatment option for children and adolescents with drug-resistant structural epilepsy, resulting in seizure freedom in the majority of cases. Beyond seizure freedom, the postsurgical stabilization or even improvement of cognitive development constitutes a fundamental objective. This study aims to address key features of cognitive development in the context of pediatric epilepsy surgery. Many surgical candidates present with severe developmental delay and cognitive deficits prior to surgery. Recent studies support that global cognitive development remains stable after surgery. Individual developmental trajectories are determined by the degree of presurgical developmental impairment, age at surgery, seizure freedom, antiepileptic drug tapering, and other case-specific factors. Compared with adults, children may better compensate for temporary postsurgical deficits in circumscribed cognitive functions such as memory. Particularly for left-sided temporal resections, children present a clear advantage in terms of postsurgical recovery with regard to verbal learning compared with adults. In the case of severe presurgical developmental impairment, minimal postsurgical improvements are often not measurable, although they are evident to patients' families and have a large impact on their quality of life. Multicenter studies with a standardized assessment protocol and longer follow-up intervals are urgently called for to provide deeper insights into the cognitive development after epilepsy surgery, to analyze the interaction between different predictors, and to facilitate the selection of appropriate candidates as well as the counseling of families.

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Surgery for Nontumoral Insular Epilepsy Explored by Stereoelectroencephalography

Neurosurgery ◽

10.1227/neu.0000000000001257 ◽

2016 ◽

Vol 79 (4) ◽

pp. 578-588 ◽

Cited By ~ 27

Author(s):

Guillaume Gras-Combe ◽

Lorella Minotti ◽

Dominique Hoffmann ◽

Alexandre Krainik ◽

Philippe Kahane ◽

...

Keyword(s):

Focal Cortical Dysplasia ◽

Intractable Epilepsy ◽

Insular Cortex ◽

Cavernous Angioma ◽

Cortical Dysplasia ◽

Electrode Placement ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Pharmacoresistant Epilepsy ◽

The Right

Abstract BACKGROUND Hidden by the perisylvian operculi, insular cortex has long been underexplored in the context of epilepsy surgery. Recent studies advocated stereoelectroencephalography (SEEG) as a reliable tool to explore insular cortex and its involvement in intractable epilepsy and suggested that insular seizures could be an underestimated entity. However, the results of insular resection to treat pharmacoresistant epilepsy are rarely reported. OBJECTIVE We report 6 consecutive cases of right insular resection performed based on anatomoelectroclinical correlations provided by SEEG. METHODS Six right-handed patients (3 male, 3 female) with drug-resistant epilepsy underwent comprehensive presurgical evaluation. Based on video electroencephalographic recordings, they all underwent SEEG evaluation with bilateral (n = 4) or unilateral right (n = 2) insular depth electrode placement. All patients had both orthogonal and oblique (1 anterior, 1 posterior) insular electrodes (n = 4-6 electrodes). Preoperative magnetic resonance imaging findings were normal in 4 patients, 1 patient had right insular focal cortical dysplasia, and 1 patient had a right opercular postoperative scar (cavernous angioma). All patients underwent right partial insular corticectomy via the subpial transopercular approach. RESULTS Intracerebral recordings demonstrated an epileptogenic zone confined to the right insula in all patients. After selective insular resection, 5 of 6 patients were seizure free (Engel class I) with a mean follow-up of 36.2 months (range, 18-68 months). Histological findings revealed focal cortical dysplasia in 5 patients and a gliosis scar in 1 patient. All patients had minor transient neurological deficit (eg, facial paresis, dysarthria). CONCLUSION Insular resection based on SEEG findings can be performed safely with a significant chance of seizure freedom.

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