Underwent Epilepsy Surgery Research Articles

Surgical treatment of epilepsy - Initial experience from a comprehensive epilepsy program in coastal South India.

The objectives of this study were to share our initial experience with epilepsy surgery and provide an overview on the surgical treatments of epilepsies. This was a retrospective analysis of the demographics and clinical and investigative features of patients who underwent epilepsy surgery between January 2016 and August 2021. Postoperative seizure outcome was categorized according to modified Engel's classification, and the minimum period of follow-up was 1 year. The study group included 30 patients with an age ranging from 6 years to 45 years (mean: 22.28 years, median: 20 years) and a male: female ratio of 20:10. The epilepsy duration before surgery ranged from 3 years to 32 years (median: 7 years). Majority of our patients underwent resective surgeries (28/30 = 93.3%), and disconnection procedures were done in two patients. This included one functional hemispherotomy and one posterior quadrantic disconnection. Temporal lobe resective surgery was the most common procedure (16/30 = 53.3%), followed by eight frontal lobe and two parietal lobe surgeries. Among resective surgeries, majority were lesional surgeries and the pathologies included mesial temporal sclerosis (4), dysembryoplastic neuroepithelial tumor (8), ganglioglioma (6), cavernoma (4), focal cortical dysplasia (2), gliosis (1), and one case of hypothalamic hamartoma. Intraoperative electrocorticography was used in all cases for optimizing surgical resection/disconnection. Nearly two-thirds of our patients (66.6%) had an Engel's Class I outcome, five patients had Engel's Class II outcome, three patients had Class III outcome, and one patient did not have any worthwhile improvement. Temporal lobe surgery patients had a better seizure outcome compared to extratemporal surgeries (84% vs. 74%). Overall, complications were minimal and short lasting, and comprised meningitis in three patients (5.6%) and transient worsening of hemiparesis following hemispherotomy in two patients. There was no mortality or long-lasting major morbidity in our patients. In carefully selected patients with drug-resistant epilepsy, surgery offers an excellent chance of becoming seizure-free with significant improvement in overall quality of life. Majority of the common epilepsy surgery procedures can be performed through a multidisciplinary approach even in centers with limited resources.

Outcomes of resective surgery in pediatric patients with drug-resistant epilepsy: A single-center study from the Eastern Mediterranean Region.

Epilepsy surgery is widely accepted as an effective therapeutic option for carefully selected patients with drug-resistant epilepsy (DRE). There is limited data on the outcome of epilepsy surgery, especially in pediatric patients from the Eastern Mediterranean region. Hence, we performed a retrospective study examining the outcomes of resective surgery in 53 pediatric patients with focal DRE. Patients with focal DRE who had undergone epilepsy surgery were included in the present study. All patients underwent a comprehensive presurgical evaluation. Postoperative seizure outcomes were classified using the Engel Epilepsy Surgery Outcome Scale. After surgery, 33 patients (62.2%) were Class I according to the Engel classification of surgical outcomes; eight patients (15.0%) were Class II, 11 (20.7%) were Class III, and one (1.8%) was Class IV. The relationships of presurgical, surgical, and postsurgical clinical variables to seizure outcomes were compared. Older age at seizure onset, older age at the time of surgery, the presence of focal to bilateral tonic-clonic seizures, seizure duration over 2 minutes, unsuccessful treatment with three or fewer antiseizure medications, lesions confined to one lobe (as demonstrated via magnetic resonance imaging [MRI]), surgical site in the temporal lobe, and histopathology including developmental tumors were significantly linked to an Engel Class I outcome. A univariate analysis of excellent surgical outcomes showed that lateralized semiology, localized interictal and ictal electroencephalogram (EEG) discharges, lateralized single-photon emission computed tomography and positron emission tomography findings, and temporal lobe resections were significantly related to excellent seizure outcomes. The results of our study are encouraging and similar to those found in other centers around the world. Epilepsy surgery remains an underutilized treatment for children with DRE and should be offered early.

Thalamic responsive neurostimulation for the treatment of refractory epilepsy: an individual patient data meta-analysis.

In recent years, the treatment of drug-resistant epilepsy (DRE) has made greater use of surgery and expanded options for neurostimulation or neuromodulation. Up to this point, responsive neurostimulation (RNS) has been very promising but has mainly used only the cortex as a target. In this individual patient data meta-analysis (IPDMA), the authors sought to establish if a novel RNS target, the thalamus, can be used to treat DRE. The literature regarding the management of DRE by targeting the thalamus with RNS was reviewed per IPDMA guidelines. Five databases were searched with keywords [((Responsive neurostimulation) OR (RNS)) AND ((thalamus) OR (thalamic) OR (Deep-seated) OR (Diencephalon) OR (limbic))] in March 2022. The median (interquartile range) age at implantation was 17 (13.5-27.5) years (n = 42) with an epilepsy duration of 12.1 (5.8-15.3) years. In total, 52.4% of patients had previously undergone epilepsy surgery, 28.6% had prior vagus nerve stimulation, and 2.4% had prior RNS. The median preimplant seizure frequency was 12 per week. The median seizure reduction at last follow-up was 73%. No study in this IPDMA reported complications, although 7 cases (16.3%) did require reoperation. Behavioral improvements and reduced antiepileptic drug dose or quantity were reported for 80% and 28.6% of patients, respectively. This review indicates that thalamic RNS may be safe and effective for treating DRE. Long-term and controlled studies on thalamic RNS for DRE would further elucidate this technique's potential benefits and complications and help guide clinical judgment in the management of DRE.

Impact of epilepsy surgery on quality of life: Systematic review and meta-analysis.

Improved quality of life (QoL) is an important outcome goal following epilepsy surgery. This study aims to quantify change in QoL for adults with drug-resistant epilepsy (DRE) who undergo epilepsy surgery, and to explore clinicodemographic factors associated with these changes. We conducted a systematic review and meta-analysis using Medline, Embase, and Cochrane Central Register of Controlled Trials. All studies reporting pre- and post-epilepsy surgery QoL scores in adults with DRE via validated instruments were included. Meta-analysis assessed the postsurgery change in QoL. Meta-regression assessed the effect of postoperative seizure outcomes on postoperative QoL as well as change in pre- and postoperative QoL scores. A total of 3774 titles and abstracts were reviewed, and ultimately 16 studies, comprising 1182 unique patients, were included. Quality of Life in Epilepsy Inventory-31 item (QOLIE-31) meta-analysis included six studies, and QOLIE-89 meta-analysis included four studies. Postoperative change in raw score was 20.5 for QOLIE-31 (95% confidence interval [CI] = 10.9-30.1, I2 = 95.5) and 12.1 for QOLIE-89 (95% CI = 8.0-16.1, I2 = 55.0%). This corresponds to clinically meaningful QOL improvements. Meta-regression demonstrated a higher postoperative QOLIE-31 score as well as change in pre- and postoperative QOLIE-31 score among studies of cohorts with higher proportions of patients with favorable seizure outcomes. At an individual study level, preoperative absence of mood disorders, better preoperative cognition, fewer trials of antiseizure medications before surgery, high levels of conscientiousness and openness to experience at the baseline, engagement in paid employment before and after surgery, and not being on antidepressants following surgery were associated with improved postoperative QoL. This study demonstrates the potential for epilepsy surgery to provide clinically meaningful improvements in QoL, as well as identifies clinicodemographic factors associated with this outcome. Limitations include substantial heterogeneity between individual studies and high risk of bias.

Short and long term prediction of seizure freedom in drug-resistant focal epilepsy surgery

BackgroundThe selection of candidates for drug-resistant focal epilepsy surgery is essential to achieve the best post-surgical outcomes. Objective: To develop two prediction models for seizure freedom in the short and long-term follow-up and from them to create a risk calculator in order to individualize the selection of candidates for surgery and future therapies in each patients. MethodsA sample of 64 consecutive patients who underwent epilepsy surgery at two Cuban tertiary health institutions between 2012 and 2020 constituted the basis for the prediction models. Two models were obtained through the novel methodology, based on biomarker selection reached by resampling methods, cross-validation and high-accuracy index measured through the area under the receiving operating curve (ROC) procedure. ResultsThe first, to pre-operative model included five predictors: epilepsy type, seizures per month, ictal pattern, interictal EEG topography and normal or abnormal magnetic resonance imaging,. it's precision was 0.77 at one year, and with four years and more 0.63. The second model including variables from the trans-surgical and post-surgical stages: the interictal discharges in the post-surgical EEG, incomplete or complete resection of the epileptogenic zone, the surgical techniques employed and disappearance of the discharge in post-resection electrocorticography; the precision of this model was 0.82 at one year, and with four years and more 0.97. ConclusionsThe introduction of trans-surgical and post-surgical variables increase the prediction of the pre-surgical model. A risk calculator was developed using these prediction models, which could be useful as an accurate tool to improve the prediction in epilepsy surgery.

An individual data-driven virtual resection model based on epileptic network dynamics in children with intractable epilepsy: a magnetoencephalography interictal activity application.

Epilepsy surgery continues to be a recommended treatment for intractable (medication-resistant) epilepsy; however, 30-70% of epilepsy surgery patients can continue to have seizures. Surgical failures are often associated with incomplete resection or inaccurate localization of the epileptogenic zone. This retrospective study aims to improve surgical outcome through in silico testing of surgical hypotheses through a personalized computational neurosurgery model created from individualized patient's magnetoencephalography recording and MRI. The framework assesses the extent of the epileptic network and evaluates underlying spike dynamics, resulting in identification of one single brain volume as a candidate for resection. Dynamic-locked networks were utilized for virtual cortical resection. This in silico protocol was tested in a cohort of 24 paediatric patients with focal drug-resistant epilepsy who underwent epilepsy surgery. Of 24 patients who were included in the analysis, 79% (19 of 24) of the models agreed with the patient's clinical surgery outcome and 21% (5 of 24) were considered as model failures (accuracy 0.79, sensitivity 0.77, specificity 0.82). Patients with unsuccessful surgery outcome typically showed a model cluster outside of the resected cavity, while those with successful surgery showed the cluster model within the cavity. Two of the model failures showed the cluster in the vicinity of the resected tissue and either a functional disconnection or lack of precision of the magnetoencephalography-MRI overlapping could explain the results. Two other cases were seizure free for 1 year but developed late recurrence. This is the first study that provides in silico personalized protocol for epilepsy surgery planning using magnetoencephalography spike network analysis. This model could provide complementary information to the traditional pre-surgical assessment methods and increase the proportion of patients achieving seizure-free outcome from surgery.

Development of De novo Functional Seizures after Epilepsy Surgery (S35.010)

<h3>Objective:</h3> The purpose of this evaluation was to identify the frequency and risk factors of de novo FS in patient after epilepsy surgery. <h3>Background:</h3> Functional seizures (FS) (also known as psychogenic non-epileptic seizures (PNES) or dissociative seizures) are seizures that mimic an epileptic seizure but have no associated epileptogenic EEG changes and are thought to have a psychological basis. Epilepsy surgery can be an effective means of treatment for patients with drug refractory seizures, but it is important to understand the complications that can arise from surgery. <h3>Design/Methods:</h3> The surgical data based showed 1116 patients who underwent epilepsy surgery from 1998 to 2022. The clinic notes were reviewed and identified 37 patients who developed de novo FS post-surgery. They were characterised by their age, sex, age of surgery, duration of epilepsy before surgery, pre-operative psychiatric co-morbidities, type/site of surgery, and post-operative complications <h3>Results:</h3> 37 patients were identified (30F, 7M). The mean age at the time of surgery was 36.2 (17–52 years). 31 patients had documented post-operative de novo FS. 16 patients had a documented pre-operative psychiatric diagnosis. 10 patients developed immediate post-operative complications and de novo FS an average of 9.8 months after surgery. 4 patients with no past psychiatric issues developed psychosis following immediate post-operative complications. Patient with no immediate post-operative complications with or without pre-operative psychiatric diagnosis developed de novo FS on average of 29.4 months after epilepsy surgery <h3>Conclusions:</h3> 1) The rate of development of de novo FS after epilepsy surgery is low (2.77%). 2) The patients who have de novo FS after surgery have high rates of pre-operative psychiatric diagnoses (43.2 %), are predominantly female (81.1%) , and have immediate post-op complications (27%). 3) Immediate post-operative complications can result in new functional seizures developing less a year after surgery <b>Disclosure:</b> Dr. Manoj has nothing to disclose. Dr. Yogarajah has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for MEWA. Dr. Yogarajah has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Forensic Access. Dr. Yogarajah has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Eopinex. The institution of Dr. Yogarajah has received research support from MRC. Dr. Yogarajah has received publishing royalties from a publication relating to health care. Dr. Huda has nothing to disclose. Ms. De Tisi has nothing to disclose. John Duncan has nothing to disclose.

Characteristics and Surgical Outcomes in a Cohort of Patients with Epilepsy and encephaloceles (P2-1.007)

<h3>Objective:</h3> To describe demographics, clinical characteristics, presurgical data, surgical approach, and outcomes of epilepsy patients with encephaloceles at The University of Kansas Medical Center. <h3>Background:</h3> Drug-resistant epilepsy (DRE) comprises around 1/3 of epilepsy patients. Encephaloceles are increasingly recognized as a DRE cause with an unknown incidence and prevalence. It can take ≥15 years to identify encephaloceles in DRE patients, with severe implications for quality of life and costs of care. In many cases, surgical resection/repair can be curative. <h3>Design/Methods:</h3> IRB approval was obtained. Informed consent was not required from individual patients. Data were retrospectively abstracted from the electronic medical record. Data analysis was performed using REDCap. <h3>Results:</h3> We identified 48 patients with epilepsy and encephaloceles in our Epilepsy Clinic. Twenty-eight (58%) were female; the mean age was 48.6 years (range 25–85). The average time from epilepsy onset to encephalocele discovery was 7.5 years (SD 8.4). Thirty-three (75%) met criteria for DRE. Twenty-three (48%) had no epilepsy risk factors, but in patients that did, trauma was the most frequent (13 pts, 27%). A lack of aura (14 patients, 29%) and psychic aura (déjà vu) (10 patients, 21%) were the two most frequently occurring auras. A slight majority had focal to bilateral tonic-clonic seizures (27 pts, 56%). Most encephaloceles were temporal (97%). A majority of encephaloceles were of unknown etiology (67%); 17% had associated venous sinus stenosis and 11% had trauma and IIH as possible etiologies, respectively. Clinical, imaging, and electrophysiologic evaluation (scalp/invasive EEG) estimated that 68% of encephaloceles caused epilepsy. Nine patients underwent epilepsy surgery. No patient undergoing surgery died. <h3>Conclusions:</h3> Most of our patients with epilepsy and encephaloceles met criteria for DRE. Early encephalocele recognition in DRE patients, followed by a prompt pre-surgical evaluation may impact seizure control, quality of life, and the financial burden of DRE on individual patients and health care systems. <b>Disclosure:</b> Dr. Mafla Delgado has nothing to disclose. Dr. Matloub has nothing to disclose. Dr. Masood has nothing to disclose. Dr. Schatmeyer has nothing to disclose. Miss Holland has nothing to disclose. Dr. Landazuri has nothing to disclose.

Accuracy of predicting surgical outcomes using interictal electrical source imaging in patients with MRI-negative intractable epilepsy

ObjectiveWe investigated the accuracy of interictal electrical source imaging (II-ESI) in localizing the epileptogenic zone in MRI-negative epilepsy patients who underwent epilepsy surgery. We also aimed to compare II-ESI's utility with other presurgical investigations and its role in guiding intracranial electroencephalography (iEEG) planning. MethodsWe retrospectively reviewed the medical records of patients with operated MRI-negative intractable epilepsy at our center between 2010 and 2016. All patients underwent video electroencephalography (EEG) monitoring, high-resolution MRI, 18 fluorodeoxyglucose positron emission tomography (FDG-PET) scans, ictal single-photon emission computed tomography (SPECT) and intracranial EEG (iEEG) monitoring. We computed II-ESI following the visual identification of interictal spikes, and outcomes were determined using Engel’s classification at 6 months after surgery. ResultsAmong 21 operated MRI-negative intractable epilepsy patients, 15 had sufficient data for II-ESI analysis. Of these, nine patients (60%) showed favorable outcomes corresponding to Engle's classification I and II. The localization accuracy of II-ESI was 53%, which was not significantly different from those of FDG-PET and ictal SPECT (47% and 45%, respectively). Among the patients, iEEG did not cover the areas suggested by II-ESIs in seven cases (47%). In two of those patients (29%), the regions indicated by II-ESIs were not resected, resulting in poor surgical outcomes. ConclusionThis study demonstrates that the localization accuracy of II-ESI was comparable to ictal SPECT and the brain FDG-PET scan. II-ESI is a simple, noninvasive method for evaluating the epileptogenic zone and guiding iEEG planning in patients with MRI-negative epilepsy.

Is There a Cognitive Decline in Pediatric Patients Following Epilepsy Surgery?

BackgroundEpilepsy surgery is currently the only way to cure drug-resistant epilepsy (DRE). The loss of epileptic activity or its propagation in the developing brain may not only result in seizure freedom but also be associated with further positive effects. Here, we analyzed the cognitive development of children and adolescents with DRE after epilepsy surgery. MethodsWe evaluated retrospectively the cognitive development of children and adolescents before and after epilepsy surgery. ResultsFifty-three children and adolescents underwent epilepsy surgery at a median age of 7.62 years. Overall seizure freedom was 86.8% at a current median observation period of 20 months. Presurgically, 81.1% had the clinical diagnosis of cognitive impairment, which was confirmed by standardized tests in 43 of 53 patients (76.7%). Further 10 patients had severe cognitive impairment rendering a standardized test impossible. The median intelligence quotient (IQ)/development quotient value was 74. After surgery, caretakers reported developmental progress in all patients, whereas the median IQ decreased slightly (P = 0.404). In eight patients the IQ points decreased after surgery; however, their individual raw scores increased in line with their reported increase in cognitive abilities. ConclusionsWe did not detect any cognitive deterioration in children following epilepsy surgery. A loss of IQ points did not correspond to a real loss of cognitive abilities. These patients developed more slowly than age-matched peers with an average development speed but profited individually as seen in their raw scores. Therefore, an individual analysis of raw scores is relevant to assess the cognitive development after surgery.

Study on the relationship between obesity and complications of Pediatric Epilepsy surgery

ObjectiveStudies have shown that obesity has a significant impact on poor surgical outcomes. However, the relationship between obesity and pediatric epilepsy surgery has not been reported. This study aimed to explore the relationship between obesity and complications of pediatric epilepsy surgery and the effect of obesity on the outcome of pediatric epilepsy surgery, and to provide a reference for weight management of children with epilepsy.MethodsA single-center retrospective analysis of complications in children undergoing epilepsy surgery was conducted. Body mass index (BMI) percentiles were adjusted by age and used as a criterion for assessing obesity in children. According to the adjusted BMI value, the children were divided into the obese group (n = 16) and nonobese group (n = 20). The intraoperative blood loss, operation time, and postoperative fever were compared between the two groups.ResultsA total of 36 children were included in the study, including 20 girls and 16 boys. The mean age of the children was 8.0 years old, ranging from 0.8 to 16.9 years old. The mean BMI was 18.1 kg/m2, ranging from 12.4 kg/m2 to 28.3 kg/m2. Sixteen of them were overweight or obese (44.4%). Obesity was associated with higher intraoperative blood loss in children with epilepsy (p = 0.04), and there was no correlation between obesity and operation time (p = 0.21). Obese children had a greater risk of postoperative fever (56.3%) than nonobese children (55.0%), but this was statistically nonsignificant (p = 0.61). The long-term follow-up outcomes showed that 23 patients (63.9%) were seizure-free (Engel grade I), 6 patients (16.7%) had Engel grade II, and 7 patients (19.4%) had Engel grade III. There was no difference in long-term seizure control outcomes between obese and nonobese groups (p = 0.682). There were no permanent neurological complications after surgery.ConclusionCompared with nonobese children with epilepsy, obese children with epilepsy had a higher intraoperative blood loss. It is necessary to conduct early weight management of children with epilepsy as long as possible.

Brain somatic mosaicism in epilepsy: Bringing results back to the clinic

Over the past decade, there has been tremendous progress in understanding brain somatic mosaicism in epilepsy in the research setting. Access to resected brain tissue samples from patients with medically refractory epilepsy undergoing epilepsy surgery has been key to making these discoveries. In this review, we discuss the gap between making discoveries in the research setting and bringing results back to the clinical setting. Current clinical genetic testing mainly uses clinically accessible tissue samples, like blood and saliva, and can detect inherited and de novo germline variants and potentially non-brain-limited mosaic variants that have resulted from post-zygotic mutation (also called “somatic mutations”). Methods developed in the research setting to detect brain-limited mosaic variants using brain tissue samples need to be further translated and validated in the clinical setting, which will allow post-resection brain tissue genetic diagnoses. However, obtaining a genetic diagnosis after surgery for refractory focal epilepsy, when brain tissue samples are available, is arguably “too late” to guide precision management. Emerging methods using cerebrospinal fluid (CSF) and stereoelectroencephalography (SEEG) electrodes hold promise for establishing genetic diagnoses pre-resection without the need for actual brain tissue. In parallel, development of curation rules for interpreting the pathogenicity of mosaic variants, which have unique considerations compared to germline variants, will assist clinically accredited laboratories and epilepsy geneticists in making genetic diagnoses. Returning results of brain-limited mosaic variants to patients and their families will end their diagnostic odyssey and advance epilepsy precision management.

Long-term seizure outcome with the surgically remediable syndrome of frontal lobe epilepsy associated with superior frontal sulcus-related dysplasia.

To assess the long-term outcome of the surgically remediable syndrome of frontal lobe epilepsy (FLE) associated with superior frontal sulcus (SFS)-related dysplasia. We retrospectively reviewed the medical charts and surgical features of 31 patients with drug-resistant frontal lobe epilepsy in our centers between 2016 and 2018. All patients underwent surgical resection. According to the epileptogenic zone (EZ), localization and resection extent were classified as (1) pure SFS group (PS group), (2) associated SFS group (AS group), and (3) no SFS group (NS group). The general characteristics, neuroradiological findings, morbidity, pathology, and long-term seizure outcome after surgery were analyzed to extract the potential value of the surgery for SFS-related dysplasia. Of 31 patients with FLE who underwent epilepsy surgery, 15 patients (nine men) were included PS group, five patients (five men) in the AS group, and 11 patients (eight men) in the NS group. Eleven patients detected abnormal focal signals in the presurgical MRI. Six patients in the PS group demonstrated the suspected focal cortical dysplasia (FCD) in the SFS detected with MRI. All patients demonstrated focal abnormal hypometabolism foci in the PET-MR co-registration. Twenty-five patients (80.6%) were seizure-free since surgery, including all 15 patients (100%) of the PS group, three in five patients (60%) of the AS group, and seven in 11 patients (63.6%) of the NS group. The difference in outcome between different groups was significant (p = 0.004, PS vs. AS group; p = 0.005, PS vs. NS group). As of the last follow-up (mean 66.2 ± 9.7months), 25 patients (80.6%) were seizure-free since surgery (Engel's class I). In addition, antiseizure medication was withdrawn in 19 patients (61.3%). Histologic examination of resected specimens revealed FCD in all 31 patients. The percentage of FCD II type was 100, 60, and 63.6% in the three different groups, respectively. SFS-related dysplasia is a neuropathologic entity with a favorable postoperative outcome. FCD II is the most common type of SFS-related dysplasia. FDG-PET co-registered with MRI should be performed in patients with suspected SFS-related dysplasia, since it may depict areas of hypometabolism suggestive of dysplasia in the absence of MRI abnormalities.

Epilepsy surgery outcomes in patients with GATOR1 gene complex variants: Report of new cases and review of literature

AimTo report seizure outcomes in children with GATOR1 gene complex disorders who underwent epilepsy surgery and perform a systematic literature search to study the available evidence. MethodsThe records of children with pathogenic/likely pathogenic variants in GATOR1 gene complex who underwent epilepsy surgery were reviewed. Clinical, radiological, neurophysiological, and histological data were extracted/summarized. The systematic review included all case series/reports and observational studies reporting on children or adults with genetic (germline or somatic) variants in the GATOR1 complex genes (DEPDC5, NPRL2, NPRL3) with focal epilepsy with/without focal cortical dysplasia who underwent epilepsy surgery; seizure outcomes were analyzed. ResultsEight children with pathogenic/likely pathogenic variants in GATOR1 complex genes were included. All had drug-resistant epilepsy. Six children had significant neurodevelopmental delay. Epilepsy surgery was performed in all; clinical seizure freedom was noted in 4 children (50%). Systematic literature search identified 17 eligible articles; additional 30 cases with patient-level data were studied. Lesional MRI brain was seen in 80% cases. The pooled rate of seizure freedom following surgery was 60%; FCD IIa was the most encountered pathology. InterpretationEpilepsy surgery may be effective in some children with GATOR1 complex gene variants. Seizure outcomes may be compromised by extensive epileptogenic zones.

Prognostic analysis in children with focal cortical dysplasia II undergoing epilepsy surgery: Clinical and radiological factors.

The aim of this study was to investigate the value of clinical profiles and radiological findings in assessing postsurgical outcomes in children with focal cortical dysplasia (FCD) II while exploring prognostic predictors of this disease. We retrospectively reviewed 50 patients with postoperative pathologically confirmed FCD II from January 2016 to June 2021. The clinical profiles and preoperative radiological findings were measured and analyzed. The patients were classified into four classes based on the Engel Class Outcome System at the last follow-up. For the analysis, the patients were divided into two categories based on Engel I and Engel II-IV, namely, seizure-free and non-seizure-free groups. Qualitative and quantitative factors were subsequently compared by groups using comparative statistics. Receiver operating characteristic (ROC) curves were used to identify the predictors of prognosis in children with FCD II. Thirty-seven patients (74%) had Engel class I outcomes. The minimum postsurgical follow-up was 1 year. At the epilepsy onset, patients who attained seizure freedom were older and less likely to have no apparent lesions on the preoperative MRI ("MRI-negative"). The non-seizure-free group exhibited a higher gray matter signal intensity ratio (GR) on 3D T1-MPRAGE images (p = 0.006), with a lower GR on T2WI images (p = 0.003) and FLAIR images (p = 0.032). The ROC curve indicated that the model that combined the GR value of all MRI sequences (AUC, 0.87; 95% CI, 0.77-0.97; p < 0.001; 86% sensitivity, 85% specificity) was able to predict prognosis accurately. A lower age at the onset or the MRI-negative finding of FCD lesions suggests a poor prognosis for children with FCD II. The model consisting of GR values from three MRI sequences facilitates the prognostic assessment of FCD II patients with subtle MRI abnormalities to prevent worse outcomes.

The clinicopathological features of ganglioglioma with CD34 expression and BRAF mutation in patients with epilepsy.

The aim of the study was to evaluate the clinicopathological features, as well as the surgical prognosis, of epilepsy-associated gangliogliomas (GG) with CD34 expression and BRAFV600E mutation. Clinical data of patients who underwent epilepsy surgery for GG were retrospectively studied. Univariate and multivariate analyses were performed to evaluate the correlations of clinical and pathological factors with molecular markers of CD34 expression and BRAFV600E mutation in GG. A total of 208 patients with GG had immunohistochemical detection of CD34 expression (positive/negative: 184/24), and among them, 89 patients had immunohistochemical detection of BRAFV600E mutation (positive/negative: 54/35). By univariate and multivariate analyses, seizure aura (p = 0.025), concordance of ictal electroencephalogram (EEG) findings (p = 0.045) and medial temporal tumor (p = 0.030) were found to be related to CD34 expression, but only hospitalization time (p = 0.042) was different for BRAF-mutated status. In addition, drug-resistant epilepsy (p = 0.040) and concordance of interictal EEG findings (p = 0.009) were found to be associated with tumor progression-free survival (PFS) in univariate analysis, but only concordance of interictal EEG findings was with significance in multivariate analysis. However, CD34 expression or BRAFV600E mutation in GG was not found to be associated with surgical outcomes of seizure control and tumor PFS. The CD34 expression or BRAFV600E mutation in GG may partly influence the distribution of clinicopathological features of patients with epilepsy, but they may be not able to predict the surgical prognosis of seizure outcome and tumor recurrence.

The Epilepsy Surgery Experience in Children With Infantile Epileptic Spasms Syndrome at a Tertiary Care Center in Canada.

Background: Infantile epileptic spasms syndrome is an epileptic encephalopathy, characterized by spasms, hypsarrhythmia, and developmental regression. Appropriately selected patients with infantile epileptic spasms syndrome may be candidates for epilepsy surgery. Methods: This is a single-center retrospective case series of children 0-18 years with a current or previous diagnosis of infantile epileptic spasms syndrome with a lesion on magnetic resonance imaging (MRI) and/or positron emission tomography scan who underwent epilepsy surgery at The Hospital for Sick Children (HSC) in Toronto, Canada. The records of 223 patients seen in the infantile epileptic spasms syndrome clinic were reviewed. Results: Nineteen patients met inclusion criteria. The etiology of infantile epileptic spasms syndrome was encephalomalacia in 6 patients (32%), malformations of cortical development in 12 patients (63%), and atypical hypoglycemic injury in 1 patient (5%). Nine patients (47%) underwent hemispherectomy, and 10 patients (53%) underwent lobectomy/lesionectomy. Three patients (16%) underwent a second epilepsy surgery. Fifteen patients (79%) were considered ILAE seizure outcome class 1 (completely seizure free; no auras) at their most recent follow-up visit. The percentage of patients who were ILAE class 1 at most recent follow-up decreased with increasing duration of epilepsy prior to surgery. Developmental outcome after surgery was improved in 14 of 19 (74%) and stable in 5 of 19 (26%) patients. Conclusions: Our study found excellent seizure freedom rates and improved developmental outcomes following epilepsy surgery in patients with a history of infantile epileptic spasms syndrome with a structural lesion detected on MRI brain. Patients who undergo surgery earlier have improved seizure freedom rates and improved developmental outcomes.

Surgical planning, histopathology findings and postoperative outcome in MR-negative extra-temporal epilepsy using intracranial EEG, functional imaging, magnetoencephalography, neuronavigation and intraoperative MRI

ObjectiveMRI-negative drug-resistant epilepsy presents a challenge when it comes to surgical planning, and surgical outcome is worse than in cases with an identified lesion. Although increasing implementation of more powerful MRI scanners and artificial intelligence has led to the detection of previously unrecognizable lesions, in some cases even postoperative pathological evaluation of electrographically epileptogenic zones shows no structural alterations. While in temporal lobe epilepsy a standardized resection approach can usually be performed, the surgical management of extra-temporal lesions is always individual. Here we present a strategy for treating patients with extra-temporal MRI-negative epilepsy focus and report our histological findings and patient outcome. MethodsPatients undergoing epilepsy surgery in the Department of Neurosurgery at the University Hospital Erlangen between 2012 and 2020 were included in the study. Inclusion criteria were: (1) failure to identify a structural lesion on preoperative high-resolution 3 Tesla MRI with a standardized epilepsy protocol and (2) preoperative intracranial EEG (iEEG) diagnostics. ResultsWe identified 8 patients corresponding to the inclusion criteria. Second look MRI analysis by an experienced neuroradiologist including the most recent analysis algorithm utilized in our clinic revealed a possible lesion in two patients. One of the patients with a clear focal cortical dysplasia (FCD) finding on a second look was excluded from further analysis. Of the other 7 patients, in one patient iEEG was performed with subdural electrodes, whereas the other 6 were evaluated with depth electrodes. MEG was performed preoperatively in all but one patient. An MEG focus was implemented in resection planning in 3 patients. FDG PET was performed in all, but only implemented in one patient. Histopathological evaluation revealed one non-lesional case, 4 cases of FCD and 2 cases with mild developmental malformation. All patients were free from permanent neurological deficits and presented with Engel 1A or 1B outcome on the last follow-up. ConclusionWe demonstrate that extra-temporal MRI-negative epilepsy can be treated successfully provided an extensive preoperative planning is performed. The most important diagnostic was stereo-EEG, whereas additional data from MEG was helpful and FDG PET was rarely useful in our cohort.

Age of readiness for epilepsy surgery

Introduction The average time between epilepsy onset and epilepsy surgery is currently approximately 20 years. In epilepsy, research on the problem of late referral for neurosurgical treatment is crucial. We aimed to investigate gender differences in the willingness of patients to undergo epilepsy surgery for focal drug-resistant epilepsy (DRE). Methods. It was a single-centre retrospective, observational, longitudinal cohort study in the outpatient and functional neurosurgery departments. We developed a structured questionnaire to examine patients' demographic data, disease history, and perceptions of neurosurgical treatment (duration of epilepsy and optimal age for neurosurgery) in two gender groups. We examined data from 53 patients; eight people were dropped out from the research. Results. Ninety-four point three per cent of outpatients and inpatients answered in the affirmative form the question about their willingness to undergo epilepsy surgery for focal DRE. There were 26 men in group one and 19 women in group two. The disease had been present for 19.26 ± 1.35 years before epilepsy surgery or the decision to undergo surgery. Patients with no significant gender differences between groups considered that the ideal age for neurosurgery was 18.66 ± 1.3 years and that the optimal duration of the disease was 6.94 ± 1.02 years, which was two point eight times shorter than the actual duration of epilepsy. Conclusions. No gender differences in willingness to undergo surgical management of focal DRE were found. The subjective time in which a patient decides to undergo epilepsy surgery is much shorter than the objective time from epilepsy onset to neurosurgery. This could be one of the solutions to the problem of late referral for epilepsy surgery.

Epilepsy with anterior temporal encephaloceles: Baseline characteristics, post-surgical outcomes, and comparison to mesial temporal sclerosis

ObjectiveTo review clinical and neuropsychological characteristics and natural history of a series of patients with temporal lobe epilepsy (TLE) and anterior temporal encephaloceles (ATE) and compare them to a similar series of TLE patients with mesial temporal sclerosis (MTS) to identify characteristics suggestive of ATE-related epilepsy. MethodsPatients with epilepsy and ATE were identified via clinic encounters and consensus epilepsy surgery conference at a Level 4 epilepsy center. The drug-resistant subset of these patients who underwent epilepsy surgery (twenty-two of thirty-five) were compared to age- and laterality-matched patients with MTS. Clinical, neuropsychological, electrophysiologic, and surgical data were abstracted through chart review. ResultsIn comparison with MTS, ATE patients were more often female, had significantly later onset of epilepsy, and did not have prior febrile seizures. In addition, ATE patients were more likely to have chronic headaches and other historical features consistent with idiopathic intracranial hypertension (IIH). Failure to identify ATE on initial imaging was common. Most patients had limited temporal cortical resections sparing mesial structures. Of the twenty ATE patients who had a long-term postsurgical follow-up, seventeen (85%) had International League Against Epilepsy (ILAE) Class 1 or 2 outcomes. SignificanceA shorter duration of epilepsy, female gender, and lack of history of febrile seizures may suggest ATE as an etiology of refractory TLE in adults. Targeted encephalocele resections can result in seizure freedom, underscoring the importance of encephalocele identification.