scholarly journals Secondary generalization of focal-onset seizures: examining the relationship between seizure propagation and epilepsy surgery outcome

2017 ◽  
Vol 117 (4) ◽  
pp. 1426-1430 ◽  
Author(s):  
Samuel B. Tomlinson ◽  
Arun Venkataraman

Surgical intervention often fails to achieve seizure-free results in patients with intractable epilepsy. Identifying features of the epileptic brain that dispose certain patients to unfavorable outcomes is critical for improving surgical candidacy assessments. Recent research by Martinet, Ahmad, Lepage, Cash, and Kramer ( J Neurosci 35: 9477–9490, 2015) suggests that pathways of secondary seizure generalization distinguish patients with favorable (i.e., seizure free) vs. unfavorable (i.e., seizure persistent) surgical outcomes, lending insights into the network mechanisms of epilepsy surgery failure.

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Abdulaziz Alsemari ◽  
Faisal Al-Otaibi ◽  
Salah Baz ◽  
Ibrahim Althubaiti ◽  
Hisham Aldhalaan ◽  
...  

Purpose. To review the postoperative seizure outcomes of patients that underwent surgery for epilepsy at King Faisal Specialist Hospital & Research Centre (KFSHRC). Methods. A descriptive retrospective study for 502 patients operated on for medically intractable epilepsy between 1998 and 2012. The surgical outcome was measured using the ILAE criteria. Results. The epilepsy surgery outcome for temporal lobe epilepsy surgery (ILAE classes 1, 2, and 3) at 12, 36, and 60 months is 79.6%, 74.2%, and 67%, respectively. The favorable 12- and 36-month outcomes for frontal lobe epilepsy surgery are 62% and 52%, respectively. For both parietal and occipital epilepsy lobe surgeries the 12- and 36-month outcomes are 67%. For multilobar epilepsy surgery, the 12- and 36-month outcomes are 65% and 50%, respectively. The 12- and 36-month outcomes for functional hemispherectomy epilepsy surgery are 64.2% and 63%, respectively. According to histopathology diagnosis, mesiotemporal sclerosis (MTS) and benign CNS tumors had the best favorable outcome after surgery at 1 year (77.27% and 84.3%, resp.,) and 3 years (76% and 75%, resp.,). The least favorable seizure-free outcome after 3 years occurred in cases with dual pathology (66.6%). Thirty-four epilepsy patients with normal magnetic resonance imaging (MRI) brain scans were surgically treated. The first- and third-year epilepsy surgery outcome of 17 temporal lobe surgeries were (53%) and (47%) seizure-free, respectively. The first- and third-year epilepsy surgery outcomes of 15 extratemporal epilepsy surgeries were (47%) and (33%) seizure-free. Conclusion. The best outcomes are achieved with temporal epilepsy surgery, mesial temporal sclerosis, and benign CNS tumor. The worst outcomes are from multilobar surgery, dual pathology, and normal MRI.


2021 ◽  
Author(s):  
Ana P Millan ◽  
Elisabeth CW van Straaten ◽  
Cornelis J Stam ◽  
Ida A Nissen ◽  
Sander Idema ◽  
...  

Background Epilepsy surgery is the treatment of choice for drug-resistant epilepsy patients. However, seizure-freedom is currently achieved in only 2/3 of the patients after surgery. In this study we have developed an individualized computational model based on functional brain networks to explore seizure propagation and the efficacy of different virtual resections. Eventually, the goal is to obtain individualized models to optimize resection strategy and outcome. Methods We have modelled seizure propagation as an epidemic process using the susceptible-infected (SI) model on individual functional networks derived from presurgical MEG. We included 10 patients who had received epilepsy surgery and for whom the surgery outcome at least one year after surgery was known. The model parameters were tuned in order to reproduce the patient-specific seizure propagation patterns as recorded with invasive EEG. We defined a personalized search algorithm that combined structural and dynamical information to find resections that maximally decreased seizure propagation for a given resection size. The optimal resection for each patient was defined as the smallest resection leading to at least a $90\%$ reduction in seizure propagation. Results The individualized model reproduced the basic aspects of seizure propagation for 9 out of 10 patients when using the resection area as the origin of epidemic spreading, and for 10 out of 10 patients with an alternative definition of the seed region. We found that, for 7 patients, the optimal resection was smaller than the resection area, and for 4 patients we also found that a resection smaller than the resection area could lead to a 100% decrease in propagation. Moreover, for two cases these alternative resections included nodes outside the resection area. Conclusion Epidemic spreading models fitted with patient specific data can capture the fundamental aspects of clinically observed seizure propagation, and can be used to test virtual resections in silico. Combined with optimization algorithms, smaller or alternative resection strategies, that are individually targeted for each patient, can be determined with the ultimate goal to improve surgery outcome.


Neurosurgery ◽  
2007 ◽  
Vol 60 (5) ◽  
pp. 873-880 ◽  
Author(s):  
Jorge A. González-Martínez ◽  
Teeradej Srikijvilaikul ◽  
Dileep Nair ◽  
William E. Bingaman

Abstract OBJECTIVE Treatment of patients who fail epilepsy surgery is problematic. Selected patients may be candidates for further surgery, potentially leading to a significant decrease in the frequency and severity of seizures. We present our long-term outcome series of highly investigated patients who failed resective epilepsy surgery and subsequently underwent reoperative resective procedures. METHODS We performed a retrospective consecutive analysis of patients who underwent reoperative procedures because of medically intractable epilepsy at our institution from 1990 to 2001. Seventy patients underwent reoperative epilepsy surgery, with 57 patients having a minimum follow-up period of 2 years. We assessed the relationship between seizure outcome and categorical variables using χ2 and Fisher's exact tests, and the relationship between outcome and continuous variables using a Wilcoxon rank-sum test. Statistical significance was set at a P value of 0.05. RESULTS Of the 57 patients (29 male and 28 female patients), the age of seizure onset ranged from 3 months to 39 years (mean, 10.7 ± 10.3 yr; median, 7 yr). The mean age at reoperation was 24.7 ± 12 years (range, 4–50 yr). The interval between first and second resection was 7 days to 16 years. The follow-up period ranged from 24 to 228 months (mean, 128 mo; mode, 132 mo). Seizure outcome was classified according to Engel's classification. Fifty-two percent of the patients had a favorable outcome (38.6% were Class I and 14.0% were Class II). Patients with tumors as their initial pathology had better outcome compared with patients with focal cortical dysplasia and mesial temporal sclerosis (P < 0.05). CONCLUSION Reoperation should be considered in selected patients failing epilepsy resective surgery because approximately 50% of patients may have benefit. Patients with cortical dysplasia and mesial temporal sclerosis are less likely to improve after reoperation.


2021 ◽  
Vol 31 (4) ◽  
Author(s):  
Lara Jehi ◽  
Kees Braun

2013 ◽  
Vol 118 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Dario J. Englot ◽  
David Ouyang ◽  
Doris D. Wang ◽  
John D. Rolston ◽  
Paul A. Garcia ◽  
...  

Object Epilepsy surgery remains significantly underutilized. The authors recently reported that the number of lobectomies for localized intractable epilepsy in the US has not changed despite the implementation of clear evidence-based guidelines 10 years ago supporting early referral for surgery. To better understand why epilepsy surgery continues to be underused, the authors' objective was to carefully examine hospital-related factors related to the following: 1) where patients are being admitted for the evaluation of epilepsy, 2) rates of utilization for surgery across hospitals, and 3) perioperative morbidity between hospitals with low versus high volumes of epilepsy surgery. Methods The authors performed a population-based cohort study of US hospitals between 1990 and 2008 using the Nationwide Inpatient Sample (NIS), stratifying epilepsy surgery rates and trends as well as perioperative morbidity rates by hospital surgical volume. Results The number of lobectomies for epilepsy performed at high-volume centers (> 15 lobectomies/year) significantly decreased between 1990 and 2008 (F = 20.4, p < 0.001), while significantly more procedures were performed at middle-volume hospitals (5–15 lobectomies/year) over time (F = 16.1, p < 0.001). No time trend was observed for hospitals performing fewer than 5 procedures per year. However, patients admitted to high-volume centers were significantly more likely to receive lobectomy than those at low-volume hospitals (relative risk 1.05, 95% CI 1.03–1.08, p < 0.001). Also, the incidence of perioperative adverse events was significantly higher at low-volume hospitals (12.9%) than at high-volume centers (6.1%) (relative risk 1.08, 95% CI 1.03–1.07, p < 0.001). Conclusions Hospital volume is an important predictor of epilepsy surgery utilization and perioperative morbidity. Patients with medically refractory epilepsy should be referred to a comprehensive epilepsy treatment center for surgical evaluation by an experienced clinical team.


1996 ◽  
Vol 2 (6) ◽  
pp. 556-564 ◽  
Author(s):  
Stephen M. Sawrie ◽  
Gordon J. Chelune ◽  
Richard I. Naugle ◽  
Hans O. Lüders

AbstractTraditional methods for assessing the neurocognitive effects of epilepsy surgery are confounded by practice effects, test-retest reliability issues, and regression to the mean. This study employs 2 methods for assessing individual change that allow direct comparison of changes across both individuals and test measures. Fifty-one medically intractable epilepsy patients completed a comprehensive neuropsychological battery twice, approximately 8 months apart, prior to any invasive monitoring or surgical intervention. First, a Reliable Change (RC) index score was computed for each test score to take into account the reliability of that measure, and a cutoff score was empirically derived to establish the limits of statistically reliable change. These indices were subsequently adjusted for expected practice effects. The second approach used a regression technique to establish “change norms” along a common metric that models both expected practice effects and regression to the mean. The RC index scores provide the clinician with a statistical means of determining whether a patient's retest performance is “significantly” changed from baseline. The regression norms for change allow the clinician to evaluate the magnitude of a given patient's change on 1 or more variables along a common metric that takes into account the reliability and stability of each test measure. Case data illustrate how these methods provide an empirically grounded means for evaluating neurocognitive outcomes following medical interventions such as epilepsy surgery. (JINS, 1996, 2, 556–564.)


QJM ◽  
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 ◽  
...  

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.


2011 ◽  
Vol 28 (3) ◽  
pp. 401-408
Author(s):  
Eri Takeshita ◽  
Eiji Nakagawa ◽  
Asako Arai ◽  
Yoshiaki Saito ◽  
Hirofumi Komaki ◽  
...  

2020 ◽  
Vol 30 (1) ◽  
pp. 85-90
Author(s):  
Yoshihiro Inoue ◽  
Kazuya Kitada ◽  
Kensuke Fujii ◽  
Syuji Kagota ◽  
Atsushi Tomioka ◽  
...  

Neurology ◽  
2020 ◽  
Vol 95 (16) ◽  
pp. e2235-e2245
Author(s):  
Päivi Nevalainen ◽  
Nicolás von Ellenrieder ◽  
Petr Klimeš ◽  
François Dubeau ◽  
Birgit Frauscher ◽  
...  

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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