Reoperation after failed resective epilepsy surgery in children

OBJECTIVEAlthough epilepsy surgery is an effective treatment option, at least 20%–40% of patients can continue to experience uncontrolled seizures resulting from incomplete resection of the lesion, epileptogenic zone, or secondary epileptogenesis. Reoperation could eliminate or improve seizures. Authors of this study evaluated outcomes following reoperation in a pediatric population.METHODSA retrospective single-center analysis of all patients who had undergone resective epilepsy surgery in the period from 2001 to 2013 was performed. After excluding children who had repeat hemispherotomy, there were 24 children who had undergone a second surgery and 2 children who had undergone a third surgery. All patients underwent MRI and video electroencephalography (VEEG) and 21 underwent magnetoencephalography (MEG) prior to reoperation.RESULTSThe mean age at the first and second surgery was 7.66 (SD 4.11) and 10.67 (SD 4.02) years, respectively. The time between operations ranged from 0.03 to 9 years. At reoperation, 8 patients underwent extended cortical resection; 8, lobectomy; 5, lesionectomy; and 3, functional hemispherotomy. One year after reoperation, 58% of the children were completely seizure free (International League Against Epilepsy [ILAE] Class 1) and 75% had a reduction in seizures (ILAE Classes 1–4). Patients with MEG clustered dipoles were more likely to be seizure free than to have persistent seizures (71% vs 40%, p = 0.08).CONCLUSIONSReoperation in children with recurrent seizures after the first epilepsy surgery could result in favorable seizure outcomes. Those with residual lesion after the first surgery should undergo complete resection of the lesion to improve seizure outcome. In addition to MRI and VEEG, MEG should be considered as part of the reevaluation prior to reoperation.

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Association of fast ripples on intracranial EEG and outcomes after epilepsy surgery

Neurology ◽

10.1212/wnl.0000000000010468 ◽

2020 ◽

Vol 95 (16) ◽

pp. e2235-e2245

Author(s):

Päivi Nevalainen ◽

Nicolás von Ellenrieder ◽

Petr Klimeš ◽

François Dubeau ◽

Birgit Frauscher ◽

...

Keyword(s):

Epilepsy Surgery ◽

Slow Wave Sleep ◽

Seizure Outcome ◽

Incomplete Resection ◽

Epileptogenic Zone ◽

Poor Prognostic Factor ◽

Individual Level ◽

Poor Outcome ◽

Surgery Outcome ◽

The Individual

ObjectiveTo examine whether fast ripples (FRs) are an accurate marker of the epileptogenic zone, we analyzed overnight stereo-EEG recordings from 43 patients and hypothesized that FR resection ratio, maximal FR rate, and FR distribution predict postsurgical seizure outcome.MethodsWe detected FRs automatically from an overnight recording edited for artifacts and visually from a 5-minute period of slow-wave sleep. We examined primarily the accuracy of removing ≥50% of total FR events or of channels with FRs to predict postsurgical seizure outcome (Engel class I = good, classes II–IV = poor) according to the whole-night and 5-minute analysis approaches. Secondarily, we examined the association of low overall FR rates or absence or incomplete resection of 1 dominant FR area with poor outcome.ResultsThe accuracy of outcome prediction was highest (81%, 95% confidence interval [CI] 67%–92%) with the use of the FR event resection ratio and whole-night recording (vs 72%, 95% CI 56%–85%, for the visual 5-minute approach). Absence of channels with FR rates >6/min (p = 0.001) and absence or incomplete resection of 1 dominant FR area (p < 0.001) were associated with poor outcome.ConclusionsFRs are accurate in predicting epilepsy surgery outcome at the individual level when overnight recordings are used. Absence of channels with high FR rates or absence of 1 dominant FR area is a poor prognostic factor that may reflect suboptimal spatial sampling of the epileptogenic zone or multifocality, rather than an inherently low sensitivity of FRs.Classification of evidenceThis study provides Class II evidence that FRs are accurate in predicting epilepsy surgery outcome.

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Factors Associated with Short-Term Seizure Recurrence in Extratemporal Epilepsy Surgery

Neuroscience and Neurological Surgery ◽

10.31579/2578-8868/196 ◽

2021 ◽

Vol 9 (3) ◽

pp. 01-07

Author(s):

Aisel Santos

Keyword(s):

Epilepsy Surgery ◽

Incomplete Resection ◽

Epileptogenic Zone ◽

Drug Resistant ◽

Seizure Recurrence ◽

Short Term ◽

Factors Associated ◽

Epileptiform Discharges ◽

One Year

Introduction: Drug-resistant extratemporal epilepsy is the second cause of referral to epilepsy surgery. Objectives: To identify factors associated with short-term seizure recurrence following extratemporal epilepsy surgery. Materials and Methods: We performed a retrospective study of 19 consecutive patients who underwent surgery for drug-resistant extratemporal epilepsy at the National Institute of Neurology and Neurosurgery of Havana, Cuba, from September 2014 to October 2019. All patients had at least one year of postoperative follow-up. Fisher's exact test was used to search for an association between dichotomous variables. A value of p≤0.05 was considered significant. Results: After one year of follow-up, seizure freedom reached 31.6% (Engel I) and 36.8% showed significant improvement in the number of seizures (Engel II). The frontal location (p=0.046) and incomplete resection of the epileptogenic zone (p=0.017), bilateral interictal discharges on the preoperative electroencephalogram (EEG) (p=0.017), the presence of epileptiform discharges on the postsurgical EEG (p=0.001), and the occurrence of seizures after the sixth month of surgery (p=0.001), were associated with seizures recurrence. Conclusions: After one year, 31.6% of patients operated on for extratemporal epilepsy were seizure-free. The incomplete resection of the epileptogenic zone and the presence of epileptogenic discharges in the postsurgical EEG, and the presence of seizures after the sixth month of surgery were the most significant factors of seizure recurrence.

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Tumour - Related Epilepsy and Post-Surgical Outcome: Tertiary Hospital Experience in Saudi Arabia

10.21203/rs.3.rs-53251/v1 ◽

2020 ◽

Author(s):

Alawi Aqel Aqel Abdullah Alattas ◽

Hindi Al-Hindi ◽

Tariq AbaAlkhail ◽

Amen Bawazir ◽

Hesham Aldhalaan ◽

...

Keyword(s):

Brain Tumors ◽

Epilepsy Surgery ◽

Tertiary Hospital ◽

First Year ◽

Seizure Outcome ◽

Low Grade ◽

Presurgical Evaluation ◽

Tumor Pathology ◽

Class 1 ◽

One Year

Abstract Background Some studies have suggested that tumor pathology significantly influence freedom from seizures post epilepsy surgery; however, there is no consensus among researchers regarding this issue. This study aims to retrospectively look for different types of tumor- related epilepsy and their outcomes in the first-year post epilepsy surgery among both adults and children. Methods In this hospital-based retrospective study, patients with drug resistant epilepsy due to brain tumor who underwent epilepsy surgery were included. Our patients underwent a thorough presurgical evaluation in an Epilepsy Monitoring Unit (EMU) before deciding to undergo surgical intervention, according to an epilepsy case-management conference. Four outcomes of interest were investigated during the first-year post epilepsy surgery.Results One hundred patients with brain tumors were included in this study (male: female = 3:2); 45 patients were children. Most of the patients (93) had low-grade gliomas or glioneuronal tumors (G/GNT). No significant differences in outcome were observed between sex, age, or histopathological categories. However, during the first year after epilepsy surgery most of the low-grade G/GNT cases showed favorable outcomes of International League Against Epilepsy (ILAE) class 1 and 2 (61.3% and 9.7%, respectively), while high-grade gliomas and meningothelial tumors showed outcomes of ILAE class 1 (40% and 100%, respectively). Conclusions One-year favorable outcome of post epilepsy surgery of different brain tumors have been achieved among both children and adults. Adequate presurgical evaluation in EMU (for long-term video-electroencephalography monitoring) to plan appropriate surgical strategy is advised. Tumor Pathology does not influence seizure outcome one-year post epilepsy surgery.

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Multivariable prediction of seizure outcome one year after resective epilepsy surgery: development of a model with independent validation

Epilepsy Research ◽

10.1016/s0920-1211(97)00083-1 ◽

1998 ◽

Vol 29 (3) ◽

pp. 185-194 ◽

Cited By ~ 38

Author(s):

Anne T Berg ◽

Thaddeus Walczak ◽

Lawrence J Hirsch ◽

Susan S Spencer

Keyword(s):

Epilepsy Surgery ◽

Seizure Outcome ◽

Independent Validation ◽

One Year

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Selection of children with drug resistant epilepsy who are candidates for epilepsy surgery: pre and post-operative evaluation

QJM ◽

10.1093/qjmed/hcab113.056 ◽

2021 ◽

Vol 114 (Supplement_1) ◽

Author(s):

Osama Salah Mohamed El Sharkawy ◽

Zeinab Anwar El kabbany ◽

Neveen Tawakol Younis ◽

Khaled Aboulfotouh Ahmad ◽

Ahmed Darwish Mahmoud ◽

...

Keyword(s):

Epilepsy Surgery ◽

Preoperative Evaluation ◽

Drug Resistant ◽

Surgery Outcome ◽

Class 1 ◽

Operative Evaluation ◽

Drug Resistant Epilepsy ◽

Stage 1 ◽

International League ◽

Selection Of

Abstract Objective To select patients with drug resistant epilepsy following up in Pediatrics Neurology Outpatient Clinic of Children's Hospital, Ain Shams University who are candidates for epilepsy surgery and to detect outcome of epilepsy surgery in such children as regards seizures control. Methods This prospective study was conducted over a period of 36 months and comprises of 3 stages. Stage 1 includes selection of candidates for epilepsy surgery and preoperative evaluation. Evaluation included clinical assessment, video EEG, MRI epilepsy protocol. Stage 2 include surgery phase where decision of surgery was made by a multidisciplinary team. Stage 3 includes post-operative evaluation as regards Seizures frequency, Seizures Severity using Chalfont score, Engel Epilepsy Surgery Outcome Scale and the International League Against Epilepsy (ILAE) outcome classification. Data was tabulated and analyzed with SSPS package for windows. Results 17 patients underwent epilepsy surgery. Results revealed significant decrease in seizures frequency and severity at 6 and 12 months after surgery. As regards Engel Epilepsy Surgery Outcome Scale 11 (64.7%) patients were class I at 12 months. As regards the ILAE outcome classification 10 (58.8%) patients are class 1 at 12 months. Conclusions epilepsy surgery can be a hope for patients with drug resistant epilepsy who are well selected and evaluated preoperatively. New studies on larger number and for longer duration are recommended.

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The proportion of seizure onset zone contacts resected is not associated with outcome following SEEG-guided resective epilepsy surgery in children

10.1101/2021.09.18.21263722 ◽

2021 ◽

Author(s):

Mehdi Khan ◽

Aswin Chari ◽

Kiran Seunarine ◽

Christin Eltze ◽

Friederike Moeller ◽

...

Keyword(s):

Epilepsy Surgery ◽

Univariate Analysis ◽

Seizure Outcome ◽

Epileptogenic Zone ◽

Imaging Data ◽

Seizure Onset ◽

Binary Logistic Regression Model ◽

Primary Analysis ◽

Seizure Onset Zone

AbstractPurposeChildren undergoing stereoelectroencephalography (SEEG)-guided epilepsy surgery represent a complex cohort. We aimed to determine whether the proportion of putative seizure onset zone (SOZ) contacts resected associates with seizure outcome in a cohort of children undergoing SEEG-guided resective epilepsy surgery.MethodsPatients who underwent SEEG-guided resective surgery over a six-year period were included. The proportion of SOZ contacts resected was determined by co-registration of pre- and post-operative imaging. Seizure outcomes were classified as seizure free (SF, Engel class I) or not seizure-free (NSF, Engel class II-IV) at last clinical follow-up.ResultsOf 94 patients undergoing SEEG, 29 underwent subsequent focal resection of whom 22 had sufficient imaging data to be included in the primary analysis (median age at surgery of 10 years, range 5-18). Fifteen (68.2%) were SF and 7 (31.8%) NSF at median follow-up of 19.5 months (range 12-46). On univariate analysis, histopathology, was the only significant factor associated with SF (p<0.05). The percentage of defined SOZ contacts resected ranged from 25-100% and was not associated with SF (p=0.89). In a binary logistic regression model, it was highly likely that histology was the only independent predictor of outcome, although the interpretation was limited by pseudo-complete separation of the data.ConclusionHistopathology is a significant predictor of surgical outcomes in children undergoing SEEG-guided resective epilepsy surgery. The percentage of SOZ contacts resected was not associated with SF. Factors such as spatial organisation of the epileptogenic zone, neurophysiological biomarkers and the prospective identification of pathological tissue may therefore play an important role.

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Resective Epilepsy Surgery for Tuberous Sclerosis in Children

Neurosurgery ◽

10.1227/neu.0000000000000875 ◽

2015 ◽

Vol 77 (4) ◽

pp. 517-524 ◽

Cited By ~ 43

Author(s):

Aria Fallah ◽

Shaun D. Rodgers ◽

Alexander G. Weil ◽

Sumeet Vadera ◽

Alireza Mansouri ◽

...

Keyword(s):

Tuberous Sclerosis ◽

Epilepsy Surgery ◽

Medical Center ◽

Cleveland Clinic ◽

Intractable Epilepsy ◽

Seizure Outcome ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Children's Hospital ◽

Children’S Hospital

Abstract BACKGROUND: There are no established variables that predict the success of curative resective epilepsy surgery in children with tuberous sclerosis complex (TSC). OBJECTIVE: We performed a multicenter observational study to identify preoperative factors associated with seizure outcome in children with TSC undergoing resective epilepsy surgery. METHODS: A retrospective chart review was performed in eligible children at New York Medical Center, Miami Children's Hospital, Cleveland Clinic Foundation, BC Children's Hospital, Hospital for Sick Children, and Sainte-Justine Hospital between January 2005 and December 2013. A time-to-event analysis was performed. The “event” was defined as seizures after resective epilepsy surgery. RESULTS: Seventy-four patients (41 male) were included. The median age of the patients at the time of surgery was 120 months (range, 3-216 months). The median time to seizure recurrence was 24.0 ± 12.7 months. Engel Class I outcome was achieved in 48 (65%) and 37 (50%) patients at 1- and 2-year follow-up, respectively. On univariate analyses, younger age at seizure onset (hazard ratio [HR]: 2.03, 95% confidence interval [CI]: 1.03-4.00, P = .04), larger size of predominant tuber (HR: 1.03, 95% CI: 0.99-1.06, P = .12), and resection larger than a tuberectomy (HR: 1.86, 95% CI: 0.92-3.74, P = .084) were associated with a longer duration of seizure freedom. In multivariate analyses, resection larger than a tuberectomy (HR: 2.90, 95% CI: 1.17-7.18, P = .022) was independently associated with a longer duration of seizure freedom. CONCLUSION: In this large consecutive cohort of children with TSC and medically intractable epilepsy, a greater extent of resection (more than just the tuber) is associated with a greater probability of seizure freedom. This suggests that the epileptogenic zone may include the cortex surrounding the presumed offending tuber.

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HIGH-FREQUENCY ELECTROCORTICOGRAPHIC MARKER OF EPILEPTOGENIC ZONE

Translational Medicine ◽

10.18705/2311-4495-2018-5-6-23-30 ◽

2019 ◽

Vol 5 (6) ◽

pp. 23-30 ◽

Cited By ~ 1

Author(s):

N. B. Arkhipova ◽

A. Yu. Ulitin ◽

M. M. Tastanbekov ◽

M. V. Aleksandrov

Keyword(s):

Surgical Treatment ◽

Epilepsy Surgery ◽

High Frequency ◽

Activity Index ◽

High Frequency Component ◽

Seizure Outcome ◽

Bioelectrical Activity ◽

Epileptogenic Zone ◽

Potential Marker ◽

Structural Epilepsy

Background. The search for new markers of the epileptogenic zone (EZ) for the surgical treatment of epilepsy is currently of relevance. Pathological high-frequency oscillations (pHFO) are considered to be a potential marker for EZ. Papers devoted to this topic are few and insufficiently systematized, mostly due to a small quantity of patients.Objective. This study was aimed to determine the diagnostic efficacy of high-frequency electrocorticography (HF ECoG) based on the epilepsy surgery outcomes.Design and methods. This is an original retrospective study of high-frequency bioelectrical activity parameters in 114 patients who underwent surgical treatment in the Polenov Neurosurgical Institute Clinic during 2017–2018. In the subgroup of patients with pharmacoresistant course of structural epilepsy (21 patients) on the preresective electrocorticogram, the pHFO index was higher than in the subgroup with intracerebral neoplasms (11 patients), which may be associated with a longer history and severity of the disease.Results. Through the analysis of the high-frequency component of the post-resective HF ECoG, it was shown that the presence or absence of pHFO in the range of 250–500 Hz does not affect the seizure outcome. The dynamics of the high-frequency activity index before and after the resection are statistically significant for the seizure outcome prediction for structural epilepsy surgery. In this study, the specificity of the pHFO dynamics analysis technique was 85.71 % and sensitivity equaled 58.33 %.Conclusion. Thus, the HF ECoG and the assessment of the dynamics of the pHFO index in the range of 250–500 Hz can complement the traditional method of intraoperative ECoG in the range of up to 70 Hz, including the prediction of the results of surgical treatment.

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A spiking neural network (SNN) for detecting high frequency oscillations (HFOs) in the intraoperative ECoG

Scientific Reports ◽

10.1038/s41598-021-85827-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Karla Burelo ◽

Mohammadali Sharifshazileh ◽

Niklaus Krayenbühl ◽

Georgia Ramantani ◽

Giacomo Indiveri ◽

...

Keyword(s):

Neural Network ◽

Real Time ◽

Epilepsy Surgery ◽

High Frequency ◽

Seizure Outcome ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Spiking Neural Network ◽

High Frequency Oscillations ◽

Neuromorphic Hardware

AbstractTo achieve seizure freedom, epilepsy surgery requires the complete resection of the epileptogenic brain tissue. In intraoperative electrocorticography (ECoG) recordings, high frequency oscillations (HFOs) generated by epileptogenic tissue can be used to tailor the resection margin. However, automatic detection of HFOs in real-time remains an open challenge. Here we present a spiking neural network (SNN) for automatic HFO detection that is optimally suited for neuromorphic hardware implementation. We trained the SNN to detect HFO signals measured from intraoperative ECoG on-line, using an independently labeled dataset (58 min, 16 recordings). We targeted the detection of HFOs in the fast ripple frequency range (250-500 Hz) and compared the network results with the labeled HFO data. We endowed the SNN with a novel artifact rejection mechanism to suppress sharp transients and demonstrate its effectiveness on the ECoG dataset. The HFO rates (median 6.6 HFO/min in pre-resection recordings) detected by this SNN are comparable to those published in the dataset (Spearman’s $$\rho$$ ρ = 0.81). The postsurgical seizure outcome was “predicted” with 100% (CI [63 100%]) accuracy for all 8 patients. These results provide a further step towards the construction of a real-time portable battery-operated HFO detection system that can be used during epilepsy surgery to guide the resection of the epileptogenic zone.

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SURG-38. SEIZURE OUTCOME AFTER EPILEPSY SURGERY IN CHILDREN WITH BRAIN TUMORS

Neuro-Oncology ◽

10.1093/neuonc/noaa215.884 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii211-ii211

Author(s):

Ayat Siddiqui ◽

Amy L McGregor ◽

James W Wheless ◽

Stephen P Fulton ◽

Sarah E Weatherspoon ◽

...

Keyword(s):

Brain Tumors ◽

Epilepsy Surgery ◽

Neurological Complication ◽

Cortical Atrophy ◽

Seizure Outcome ◽

Childhood Brain Tumors ◽

Institutional Review ◽

Intractable Seizures ◽

Class 1

Abstract INTRODUCTION Epilepsy is a common chronic neurological complication of childhood brain tumors and seizures are refractory to medical therapy in up to 10% of patients. Referral for a diagnostic evaluation is recommended in patients with seizures refractory to ≥2 anti-epileptic drugs (AED). Utility of epilepsy surgery is not established in children with brain tumors. OBJECTIVE Primary aim of this study was to determine seizure outcome after epilepsy surgery in children with childhood brain tumors. METHODS Institutional Review Board’s approval was obtained for this retrospective study. A diagnosis of childhood brain tumor and a referral to the epilepsy monitoring unit (EMU) were required to be included in this study. Seizure outcome was defined according to International League Against Epilepsy (ILAE) outcome scale. Pre and post-operative MRIs were reviewed. RESULTS Forty-two children were referred to the EMU from May 2004 to July 2019. Of the 10 patients that underwent epilepsy surgery, 7 (70%) had pre-surgery frequency of >10 seizures/month and 3(30%) of these had multiple daily seizures; the rest had 3-4 seizures/month. All were taking ≥3 AEDs. Median time from first seizure to surgery was 83.7 months (range 24.3-151.6). At a median follow-up of 67.5 months (range 4.9-133.5) after epilepsy surgery, 60% reported no seizures in the 6-months before the last follow-up. Three (30%) had ILAE class-1 outcome, 4 (40%) class-3, and 3 (30%) were class-4. One child was off AEDs and the others were on a single AED at last follow-up. No post-operative neurological or cognitive deficits were recognized. Focal cortical atrophy was present in 40% of children before and in 30% after surgery. CONCLUSION Epilepsy surgery improved seizure outcome in all children that had epilepsy surgery and reduced the number of AEDs needed to treat seizures. Children with brain tumors and intractable seizures should be referred for epilepsy surgery evaluation.

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