scholarly journals Predictive Factors of Surgical Outcome in Frontal Lobe Epilepsy Explored with Stereoelectroencephalography

Neurosurgery ◽  
2017 ◽  
Vol 83 (2) ◽  
pp. 217-225 ◽  
Author(s):  
Francesca Bonini ◽  
Aileen McGonigal ◽  
Didier Scavarda ◽  
Romain Carron ◽  
Jean Régis ◽  
...  

Abstract BACKGROUND Resective surgery established treatment for pharmacoresistant frontal lobe epilepsy (FLE), but seizure outcome and prognostic indicators are poorly characterized and vary between studies. OBJECTIVE To study long-term seizure outcome and identify prognostic factors. METHODS We retrospectively analyzed 42 FLE patients having undergone surgical resection, mostly preceded by invasive recordings with stereoelectroencephalography (SEEG). Postsurgical outcome up to 10-yr follow-up and prognostic indicators were analyzed using Kaplan–Meier analysis and multivariate and conditional inference procedures. RESULTS At the time of last follow-up, 57.1% of patients were seizure-free. The estimated chance of seizure freedom was 67% (95% confidence interval [CI]: 54-83) at 6 mo, 59% (95% CI: 46-76) at 1 yr, 53% (95% CI: 40-71) at 2 yr, and 46% (95% CI: 32-66) at 5 yr. Most relapses (83%) occurred within the first 12 mo. Multivariate analysis showed that completeness of resection of the epileptogenic zone (EZ) as defined by SEEG was the main predictor of seizure outcome. According to conditional inference trees, in patients with complete resection of the EZ, focal cortical dysplasia as etiology and focal EZ were positive prognostic indicators. No difference in outcome was found in patients with positive vs negative magnetic resonance imaging. CONCLUSION Surgical resection in drug-resistant FLE can be a successful therapeutic approach, even in the absence of neuroradiologically visible lesions. SEEG may be highly useful in both nonlesional and lesional FLE cases, because complete resection of the EZ as defined by SEEG is associated with better prognosis.

2007 ◽  
Vol 7 (4) ◽  
pp. 98-99 ◽  
Author(s):  
John W. Miller

Surgical Outcome and Prognostic Factors of Frontal Lobe Epilepsy Surgery. Jeha LE, Najm I, Bingaman W, Dinner D, Widdess-Walsh P, Luders H. Brain 2007;130(Pt 2):574–584. Epub 2007 Jan 5. Frontal lobe epilepsy (FLE) surgery is the second most common surgery performed to treat pharmacoresistant epilepsy. Yet, little is known about long-term seizure outcome following frontal lobectomy. The aim of this study is to investigate the trends in longitudinal outcome and identify potential prognostic indicators in a cohort of FLE patients investigated using modern diagnostic techniques. We reviewed 70 patients who underwent a frontal lobectomy between 1995 and 2003 (mean follow-up 4.1 ± 3 years). Data were analysed using survival analysis and multivariate regression with Cox proportional hazard models. A favourable outcome was defined as complete seizure-freedom, allowing for auras and seizures restricted to the first post-operative week. The estimated probability of complete seizure-freedom was 55.7% [95% confidence interval (CI) = 50–62] at 1 post-operative year, 45.1% (95% CI = 39–51) at 3 years, and 30.1% (95% CI = 21–39) at 5 years. Eighty per cent of seizure recurrences occurred within the first 6 post-operative months. Late remissions and relapses occurred, but were rare. After multivariate analysis, the following variables retained their significance as independent predictors of seizure recurrence: MRI-negative malformation of cortical development as disease aetiology [risk ratio (RR) = 2.22, 95% CI = 1.40–3.47], any extrafrontal MRI abnormality (RR = 1.75, 95% CI = 1.12–2.69), generalized/non-localized ictal EEG patterns (RR = 1.83, 95% CI = 1.15–2.87), occurrence of acute post-operative seizures (RR = 2.17, 95% CI = 1.50–3.14) and incomplete surgical resection (RR = 2.56, 95% CI = 1.66–4.05) (log likelihood-ratio test P-value < 0.0001). More than half of patients in favourable prognostic categories were seizure-free at 3 years, and up to 40% were seizure-free at 5 years, compared to <15% in those with unfavourable outcome predictors. These data underscore the importance of appropriate selection of potential surgical candidates.


Neurosurgery ◽  
2014 ◽  
Vol 75 (3) ◽  
pp. 258-268 ◽  
Author(s):  
Jorge Gonzalez-Martinez ◽  
Jeffrey Mullin ◽  
Juan Bulacio ◽  
Ajay Gupta ◽  
Rei Enatsu ◽  
...  

Abstract BACKGROUND: Although stereoelectroencephalography (SEEG) has been shown to be a valuable tool for preoperative decision making in focal epilepsy, there are few reports addressing the utility and safety of SEEG methodology applied to children and adolescents. OBJECTIVE: To present the results of our early experience using SEEG in pediatric patients with difficult-to-localize epilepsy who were not considered candidates for subdural grid evaluation. METHODS: Thirty children and adolescents with the diagnosis of medically refractory focal epilepsy (not considered ideal candidates for subdural grids and strip placement) underwent SEEG implantation. Demographics, electrophysiological localization of the hypothetical epileptogenic zone, complications, and seizure outcome after resections were analyzed. RESULTS: Eighteen patients (60%) underwent resections after SEEG implantations. In patients who did not undergo resections (12 patients), reasons included failure to localize the epileptogenic zone (4 patients); multifocal epileptogenic zone (4 patients); epileptogenic zone located in eloquent cortex, preventing resection (3 patients); and improvement in seizures after the implantation (1 patient). In patients who subsequently underwent resections, 10 patients (55.5%) were seizure free (Engel class I) and 5 patients (27.7%) experienced seizure improvement (Engel class II or III) at the end of the follow-up period (mean, 25.9 months; range, 12 to 47 months). The complication rate in SEEG implantations was 3%. CONCLUSION: The SEEG methodology is safe and should be considered in children/adolescents with difficult-to-localize epilepsy. When applied to highly complex and difficult-to-localize pediatric patients, SEEG may provide an additional opportunity for seizure freedom in association with a low morbidity rate.


2020 ◽  
Vol 133 (4) ◽  
pp. 950-959
Author(s):  
Alain Bouthillier ◽  
Alexander G. Weil ◽  
Laurence Martineau ◽  
Laurent Létourneau-Guillon ◽  
Dang Khoa Nguyen

OBJECTIVEPatients with refractory epilepsy of operculoinsular origin are often denied potentially effective surgical treatment with operculoinsular cortectomy (also termed operculoinsulectomy) because of feared complications and the paucity of surgical series with a significant number of cases documenting seizure control outcome. The goal of this study was to document seizure control outcome after operculoinsular cortectomy in a group of patients investigated and treated by an epilepsy team with 20 years of experience with this specific technique.METHODSClinical, imaging, surgical, and seizure control outcome data of all patients who underwent surgery for refractory epilepsy requiring an operculoinsular cortectomy were retrospectively reviewed. Tumors and progressive encephalitis cases were excluded. Descriptive and uni- and multivariate analyses were done to determine seizure control outcome and predictors.RESULTSForty-three patients with 44 operculoinsular cortectomies were studied. Kaplan-Meier estimates of complete seizure freedom (first seizure recurrence excluding auras) for years 0.5, 1, 2, and 5 were 70.2%, 70.2%, 65.0%, and 65.0%, respectively. With patients with more than 1 year of follow-up, seizure control outcome Engel class I was achieved in 76.9% (mean follow-up duration 5.8 years; range 1.25–20 years). With multivariate analysis, unfavorable seizure outcome predictors were frontal lobe–like seizure semiology, shorter duration of epilepsy, and the use of intracranial electrodes for invasive monitoring. Suspected causes of recurrent seizures were sparing of the language cortex part of the focus, subtotal resection of cortical dysplasia/polymicrogyria, bilateral epilepsy, and residual epileptic cortex with normal preoperative MRI studies (insula, frontal lobe, posterior parieto-temporal, orbitofrontal).CONCLUSIONSThe surgical treatment of operculoinsular refractory epilepsy is as effective as epilepsy surgeries in other brain areas. These patients should be referred to centers with appropriate experience. A frontal lobe–like seizure semiology should command more sampling with invasive monitoring. Recordings with intracranial electrodes are not always required if the noninvasive investigation is conclusive. The complete resection of the epileptic zone is crucial to achieve good seizure control outcome.


Neurosurgery ◽  
2011 ◽  
Vol 69 (1) ◽  
pp. 80-94 ◽  
Author(s):  
Jean Régis ◽  
Manabu Tamura ◽  
Michael C Park ◽  
Aileen McGonigal ◽  
Denis Rivière ◽  
...  

Abstract BACKGROUND: Epilepsy surgery for magnetic resonance imaging (MRI)-negative patients has a less favorable outcome. OBJECTIVE: Detection of subclinical abnormal gyration (SAG) patterns and their potential contribution to assessment of the topography of the epileptogenic zone (EZ) is addressed in MRI-negative patients with frontal lobe epilepsy. METHODS: Between September 1998 and July 2005, 12 MRI-negative frontal lobe epilepsy patients underwent stereoelectroencephalography with postcorticectomy follow-up of longer than 1 year (average, 3.3 years). Original software (BrainVISA/Anatomist, http://brainvisa.info) trained on a database of normal volunteers was used to determine which sulci had morphology out of the normal range (SAG). Topography of the EZ, SAG pattern, corticectomy, postoperative seizure control, and histopathology were analyzed. RESULTS: At last follow-up, 8 of 12 patients (66.7%) were Engel class I (7 IA and 1 IB), 2 class II, and 2 class IV. Small focal cortical dysplasia was histologically diagnosed in 9 of the 12 patients (75%), including 7 of 8 seizure-free patients (87.5%). A SAG pattern was found to be in the EZ area in 9 patients (75%), in the ipsilateral frontal lobe out of the EZ in 2, and limited to the contralateral hemisphere in 1. CONCLUSION: SAG patterns appear to be associated with the topography of the EZ in MRI-negative frontal lobe epilepsy and may have a useful role in preoperative assessment. Small focal cortical dysplasia not detected with MRI is often found on histopathological examination, particularly in the depth of the posterior part of the superior frontal sulcus and intermediate frontal sulcus, suggesting a specific developmental critical zone in these locations.


Neurosurgery ◽  
2017 ◽  
Vol 83 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Georgia Ramantani ◽  
Navah Ester Kadish ◽  
Hans Mayer ◽  
Constantin Anastasopoulos ◽  
Kathrin Wagner ◽  
...  

Abstract BACKGROUND Although frontal lobe resections account for one-third of intralobar resections in pediatric epilepsy surgery, there is a dearth of information regarding long-term seizure freedom, overall cognitive and adaptive functioning. OBJECTIVE To identify outcome predictors and define the appropriate timing for surgery. METHODS We retrospectively analyzed the data of 75 consecutive patients aged 10.0 ± 4.9 yr at surgery that had an 8.1 yr mean follow-up. RESULTS Etiology comprised focal cortical dysplasia (FCD) in 71% and benign tumors in 16% cases. All patients but one had a magnetic resonance imaging-visible lesion. At last follow-up, 63% patients remained seizure-free and 37% had discontinued antiepileptic drugs. Presurgical predictors of seizure freedom were a shorter epilepsy duration, strictly regional epileptic discharges in electroencephalography (EEG), and an epileptogenic zone and/or lesion distant from eloquent cortex. Postsurgical predictors were the completeness of resection and the lack of early postoperative seizures or epileptic discharges in EEG. Higher presurgical overall cognitive and adaptive functioning was related to later epilepsy onset and to a sublobar epileptogenic zone and/or lesion. Following surgery, scores remained stable in the majority of patients. Postsurgical gains were determined by higher presurgical performance and tumors vs FCD. CONCLUSION Our findings highlight the favorable long-term outcomes following frontal lobe epilepsy surgery in childhood and adolescence and underline the importance of early surgical intervention in selected candidates. Early postsurgical relapses and epileptic discharges in EEG constitute key markers of treatment failure and should prompt timely reevaluation. Postsurgical overall cognitive and adaptive functioning is stable in most patients, whereas those with benign tumors have higher chances of improvement.


2012 ◽  
Vol 116 (5) ◽  
pp. 1042-1048 ◽  
Author(s):  
Dario J. Englot ◽  
Doris D. Wang ◽  
John D. Rolston ◽  
Tina T. Shih ◽  
Edward F. Chang

Object Frontal lobe epilepsy (FLE) is the second-most common focal epilepsy syndrome, and seizures are medically refractory in many patients. Although various studies have examined rates and predictors of seizure freedom after resection for FLE, there is significant variability in their results due to patient diversity, and inadequate follow-up may lead to an overestimation of long-term seizure freedom. Methods In this paper the authors report a systematic review and meta-analysis of long-term seizure outcomes and predictors of response after resection for intractable FLE. Only studies of at least 10 patients examining seizure freedom after FLE surgery with postoperative follow-up duration of at least 48 months were included. Results Across 1199 patients in 21 studies, the overall rate of postoperative seizure freedom (Engel Class I outcome) was 45.1%. No trend in seizure outcomes across all studies was observed over time. Significant predictors of long-term seizure freedom included lesional epilepsy origin (relative risk [RR] 1.67, 95% CI 1.36–28.6), abnormal preoperative MRI (RR 1.64, 95% CI 1.32–2.08), and localized frontal resection versus more extensive lobectomy with or without an extrafrontal component (RR 1.71, 95% CI 1.26–2.43). Within lesional FLE cases, gross-total resection led to significantly improved outcome versus subtotal lesionectomy (RR 1.99, 95% CI 1.47–2.84). Conclusions These findings suggest that FLE patients with a focal and identifiable lesion are more likely to achieve seizure freedom than those with a more poorly defined epileptic focus. While seizure freedom can be achieved in the surgical treatment of medically refractory FLE, these findings illustrate the compelling need for improved noninvasive and invasive localization techniques in FLE.


2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii45-ii45
Author(s):  
M Tomschik ◽  
E Horner ◽  
G Kasprian ◽  
C Dorfer ◽  
K Roessler

Abstract BACKGROUND Gangliogliomas (GG) and dysembryoplastic neuroepithelial tumors (DNET) are glioneural tumors associated with treatment refractory seizures, especially in younger patients. Because there is a relative paucity of data on which factors predispose patients for recurrences, we analyzed our own cohort treated over the last 25 years. MATERIAL AND METHODS We performed a retrospective analysis of all patients undergoing resection of a glioneural tumor with a minimum follow up of one year. Surgery type, histological findings, and seizure outcome were extracted from patient records. Recurrence was defined as new tumor lesions in previously unremarkable parenchyma or tumor growth of a residual lesion. We performed a Mann-Whitney-U test to determine statistical significance of differences in continuous variables and Fisher’s exact test in categorical. RESULTS In total, 109 patients were operated between March 1994 to March and followed for a median of 62.4 months (range 12–281 months). The average age of patients at the time of surgery was 21.2 years with 60 patients belonging to the pediatric population. Complete lesionectomies were the goal in 72 cases, extended resections in 10, and partial resection due to proximity of eloquent areas was performed in 27 cases. 77 tumors were classified histologically as a GG and 32 as a DNET. The temporal lobe was the most common site of origin with 65 tumors (59.6%) being found there. On postoperative MRI, complete resection was achieved in 76 cases. Local tumor recurrences were seen in 14 patients (12 GG and 2 DNET), 9 of which occurred in patients with apparently complete resection. Overall, only one malignant transformation of a GG was observed. Age at surgery was significantly lower for patients with later recurrence (11.9 yrs vs. 22.6 yrs for patients without recurrence, p=0.0047). A second surgery was performed in 11 patients with previously incomplete resections (33%) and 7 patients with complete resection (9.2%), p=0.0038. 95 patients (87.2%) had preoperative seizures for a median of 26 months before surgery. One year after surgery, a documented ILAE outcome was available for 90 of these patients and 63 (70%) were seizure free one year after surgery. While 45 patients with epilepsy (47.4%) had at least one seizure relapse after surgery - most often associated with AED withdrawal or tumor recurrence - medical therapy and repeat resection allowed 76 patients (80%) to be seizure free for over one year at their last follow up. Age at surgery was not a significant predictor of seizure freedom. CONCLUSION Glioneural tumors are highly epileptogenic but neurosurgical resection allows seizure freedom in the large majority of these patients. Tumor recurrences were more likely in younger patients and incomplete resections predisposed patients to need another surgery. Resection extent on MRI does not appear to be a reliable marker for future recurrence risk.


2021 ◽  
Author(s):  
Amr Ali Hasanain ◽  
Mohamed Sawan ◽  
Ahmed Mohamed Ali

Abstract BACKGROUNDExtratemporal lesional epilepsy can be managed with various surgical techniques such as simple lesionectomy or more extensive resections, all of which aim at targeting the epileptogenic zone which is the key for achieving a favorable outcome. This study aimed at evaluating the effectiveness of lesionectomy in the treatment of extra-temporal epilepsy associated with a lesion on radiological imaging, and to show the effect of lesional factors on seizure outcome including the anatomical location, the relation to cerebral parenchyma, the extent of surgical excision and the histopathological nature of the lesion.METHODSA prospective study on 20 patients presenting with focal epilepsy, or focal epilepsy with secondary generalized seizures with evidence of focal lesion in an extratemporal location on MRI. Lesionectomy was done and we used the Engel’s classification for seizure outcome.RESULTSLesions were mostly tumors (85 %). The frontal lobe is the most frequent locations (60 %). Low-grade glioma represented 35 % while meningioma represented 45 % of all lesions (both intra-axial and extra-axial). Four patients were lost during follow up (mean 23.31 months). For the remaining 16 patients, 13 cases were tumors (81.25%). Lesionectomy achieved seizure freedom in 68.75 %.CONCLUSIONSIn a country with limited resources, lesionectomy is a valid technique for epilepsy surgery as long as the radiological data and the seizure semiology are concordant. Total lesionectomy provides good seizure control when the clinical and radiological data are concordant with seizure semiology, in particular with tumor-related epilepsy. A study comparing postoperative seizure outcome between intra-axial and extra-axial lesions on a larger scale and with a longer follow up period is recommended.


2015 ◽  
Vol 15 (6) ◽  
pp. 644-650 ◽  
Author(s):  
Chima O. Oluigbo ◽  
Jichuan Wang ◽  
Matthew T. Whitehead ◽  
Suresh Magge ◽  
John S. Myseros ◽  
...  

OBJECT Focal cortical dysplasia (FCD) is one of the most common causes of intractable epilepsy leading to surgery in children. The predictors of seizure freedom after surgical management for FCD are still unclear. The objective of this study was to perform a volumetric analysis of factors shown on the preresection and postresection brain MRI scans of patients who had undergone resective epilepsy surgery for cortical dysplasia and to determine the influence of these factors on seizure outcome. METHODS The authors reviewed the medical records and brain images of 43 consecutive patients with focal MRI-documented abnormalities and a pathological diagnosis of FCD who had undergone surgical treatment for refractory epilepsy. Preoperative lesion volume and postoperative resection volume were calculated by manual segmentation using OsiriX PRO software. RESULTS Forty-three patients underwent first-time surgery for resection of an FCD. The age range of these patients at the time of surgery ranged from 2 months to 21.8 years (mean age 7.3 years). The median duration of follow-up was 20 months. The mean age at onset was 31.6 months (range 1 day to 168 months). Complete resection of the area of an FCD, as adjudged from the postoperative brain MR images, was significantly associated with seizure control (p = 0.0005). The odds of having good seizure control among those who underwent complete resection were about 6 times higher than those among the patients who did not undergo complete resection. Seizure control was not significantly associated with lesion volume (p = 0.46) or perilesion resection volume (p = 0.86). CONCLUSIONS The completeness of FCD resection in children is a significant predictor of seizure freedom. Neither lesion volume nor the further resection of perilesional tissue is predictive of seizure freedom.


2021 ◽  
Author(s):  
Mehdi Khan ◽  
Aswin Chari ◽  
Kiran Seunarine ◽  
Christin Eltze ◽  
Friederike Moeller ◽  
...  

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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