Underwent Epilepsy Surgery Research Articles

Dramatic improvement of drug-resistant epilepsy following cerebral infarction: a case report

BackgroundAn estimated 30% of patients with epilepsy experience drug-resistant epilepsy, which is the failure to control seizures despite the use of two or more antiseizure medications. Although other treatment options are considered, these alternatives often prove ineffective.Case presentationA 60-year-old East Asian male patient diagnosed with drug-resistant epilepsy experienced several seizures daily despite being on eight different antiseizure medications. Seizures began at age 15. He underwent epilepsy surgery at age 34, yet the seizures persisted. An electroencephalogram revealed multifocal sharp waves in the left hemisphere. Cerebral hemorrhages at ages 47, 50, and 56 were caused by head trauma during seizures. The patient became wheelchair-bound and now resides in a nursing home. At age 58, after suffering an acute cerebral infarction due to occlusion of the left internal carotid artery, his daily seizures ceased entirely. Despite remaining wheelchair-bound, he did not experience a significant decline in his quality of life. The cessation of seizures has reduced his risk of further trauma, and he has remained seizure-free for 3 years on just one antiseizure medication.ConclusionSurgical treatments for epilepsy often fail, with insufficient resection being a leading cause of these failures. In some cases, extensive destruction from an ischemic stroke may be beneficial. Furthermore, this case suggests that infarction therapy could be a potential treatment for patients with drug-resistant epilepsy.

Exploration of epileptic networks in temporal lobe encephaloceles with stereotactic EEG: Electroclinical characteristics and surgical outcomes.

Temporal lobe encephaloceles (TLEN) have been implicated as a cause of temporal lobe epilepsy (TLE), the treatment which is primarily surgical; however, there is no clear consensus on the optimal surgical approach, because it is unclear whether TLE related to TLEN can be addressed by a restricted encephalocele resection or if a more extensive resection is required. The aim of the current article is to report the clinical and electrophysiological profile of patients with TLE secondary to TLEN who underwent stereotactic electroencephalography (SEEG) implantation to identify the epileptogenic network. A retrospective review was performed of patients with TLE related to TLEN who underwent SEEG implantation. Medical charts were reviewed for demographic data, the results of noninvasive and invasive investigations, and operative details. Surgical outcomes were based on Engel classification with at least 6 months follow-up. Nine patients were identified. The mean age at epilepsy onset was 28 years (range, 15-41 years), and 7/9 patients were female. Scalp EEG revealed interictal epileptiform activity most often maximum in the frontotemporal and/or temporal regions. A discrete TLEN was often not identified on initial imaging, but was identified during re-review or at the time of surgery. Seizure onset zones during SEEG were localized to the mesial temporal structures, the temporal pole, or both. One patient became seizure-free following SEEG and another refused further surgery. Of the 7 patients who underwent epilepsy surgery, 5/7 underwent an anterior temporal lobectomy-surgical outcomes were favorable, with 5/7 achieving Engel I outcomes. Invasive SEEG monitoring demonstrated ictal onsets may not be restricted to the TLEN, and often the temporal pole and mesial structures are involved at seizure onset. Ictal propagation patterns vary significantly, which may be related to the underlying pathology and explain the variability in semiology. These findings may inform surgical treatment options. Temporal lobe encephaloceles can cause intractable epilepsy, although their presence may be missed on routine imaging. The management of encephaloceles is primarily surgical; however, the optimal surgical approach can be unclear. Invasive monitoring with SEEG may help characterize the epileptogenic network and result in more optimal surgical outcomes.

Development of a stereo-EEG based seizure matching system for clinical decision making in epilepsy surgery.

Objective.The proportion of patients becoming seizure-free after epilepsy surgery has stagnated. Large multi-center stereo-electroencephalography (SEEG) datasets can allow comparing new patients to past similar cases and making clinical decisions with the knowledge of how cases were treated in the past. However, the complexity of these evaluations makes the manual search for similar patients impractical. We aim to develop an automated system that electrographically and anatomically matches seizures to those in a database. Additionally, since features that define seizure similarity are unknown, we evaluate the agreement and features among experts in classifying similarity.Approach.We utilized 320 SEEG seizures from 95 consecutive patients who underwent epilepsy surgery. Eight international experts evaluated seizure-pair similarity using a four-level similarity score. As our primary outcome, we developed and validated an automated seizure matching system by employing patient data marked by independent experts. Secondary outcomes included the inter-rater agreement (IRA) and features for classifying seizure similarity.Main results.The seizure matching system achieved a median area-under-the-curve of 0.76 (interquartile range, 0.1), indicating its feasibility. Six distinct seizure similarity features were identified and proved effective: onset region, onset pattern, propagation region, duration, extent of spread, and propagation speed. Among these features, the onset region showed the strongest correlation with expert scores (Spearman's rho = 0.75,p< 0.001). Additionally, the moderate IRA confirmed the practicality of our approach with an agreement of 73.9% (7%), and Gwet's kappa of 0.45 (0.16). Further, the interoperability of the system was validated on seizures from five centers.Significance.We demonstrated the feasibility and validity of a SEEG seizure matching system across patients, effectively mirroring the expertise of epileptologists. This novel system can identify patients with seizures similar to that of a patient being evaluated, thus optimizing the treatment plan by considering the results of treating similar patients in the past, potentially improving surgery outcome.

Beyond seizure freedom: Reduction in anti-seizure medication after epilepsy surgery

IntroductionPatients considering therapeutic epilepsy surgery often seek to decrease the number of anti-seizure medications (ASMs) they need. Predicting such reductions remains challenging. Although predictors of seizure freedom after epilepsy surgery are well-established, long-term outcomes remain modest and factors associated with ASM reduction, even in the absence of seizure freedom, may improve surgical planning to align with patient goals. MethodsWe studied a large multi-institutional cohort of patients who underwent epilepsy surgery between 2001 and 2022, with a minimum of two years follow-up. Preoperative features, including duration of epilepsy, epilepsy etiology, non-invasive investigation data, and total number of ASMs prescribed immediately prior to surgery were extracted for each patient. Primary endpoints included likelihood of ASM reduction and ASM freedom at multiple post-operative time points up to 15 years and stratified by seizure control. ResultsA total of 250 patients were followed for a median of 6.0 (range 2, 22) years after intracranial EEG (iEEG) surgery. Significant ASM reduction was only observed in those who underwent subsequent resection, whereas those undergoing neuromodulation saw their ASM usage maintained. Engel I outcomes were the strongest driver of ASM reduction. In patients with persistent seizures, patients with lateralized seizure onset zones (SOZs) also achieved sustained ASM reduction over time. Similarly, an increased number of preoperative ASMs also corresponded to a higher likelihood of ASM reduction across all follow-up periods. Other preoperative factors, including seizure etiology, did not independently influence ASM reduction. ConclusionsEven patients with persistent seizures after epilepsy surgery can observe meaningful ASM reduction during long-term follow-up. ASM reduction may be a relevant secondary outcome measure for epilepsy surgery.

Epidemiology and real-world management of childhood epilepsy in Japan: A descriptive study using a health claim database

IntroductionThe purpose of this epidemiological study was to assess the prevalence, comorbidities, and real-world management of childhood epilepsy to provide insights for enhancing epilepsy management and medical resource planning. Materials and methodsThe study encompassed insured individuals aged 0–17 years as of December 2018 who were registered at any point in 2018, for at least part of the year, in a Japanese health claims database spanning January—December 2018. Epilepsy was defined as a diagnosis of epilepsy based on the International Classification of Diseases, 10th Revision codes, and a claimed management fee for epilepsy or an anti-seizure medication (ASM) prescription for longer than 4 weeks. The prevalence of epilepsy, patient characteristics, including comorbidities, and management status, such as prescription of ASMs, were evaluated. ResultsAmong 1528,905 registered children, 9279 were identified as having epilepsy. The prevalence of epilepsy was the lowest at 1.97 per 1000 population (95 % confidence interval [CI] 1.80–2.15) in the 0–2-year age group and increased with age to 9.34 per 1000 population (95 % CI 8.98–9.72) in the 15–17-year age group, with a significantly higher prevalence in boys than in girls in the ≥12-year age group. ASMs were prescribed to 88.3 %–91.9 % of the patients. Moreover, 27 (0.29 %) patients underwent epilepsy surgery. The frequency of claiming intravenous ASMs and long-term electroencephalogram fees increased with a decrease in age. ConclusionsOur findings indicate that young children receive more medical resources than adolescents and that epilepsy surgery is underutilized. Further investigations will help improve the management of and develop measures against epilepsy.

Preliminary observation on clinical outcome and safety of surgery in early infants (

ObjectiveTo investigate the clinical outcomes and safety of surgery in infants (< 12 months of age) with drug-resistant epilepsy, clarify surgical indications, and select appropriate surgical methods. MethodsThis was a retrospective analysis of infants with drug-resistant epilepsy who underwent epilepsy surgery and were followed up for > 6 months at the Epilepsy Center of Shenzhen Children's Hospital. Clinical data included etiology, seizure type, surgical procedure, preoperative auxiliary examinations, pathological findings, and intraoperative and postoperative complications. Clinical outcomes were assessed based on postoperative seizure frequency, antiseizure medicines (ASMs) use, and neurocognitive development. Intraoperative blood loss, operative duration, postoperative complications, and duration of intensive care were evaluated to assess the safety of epilepsy surgery. Univariate and logistic analyses were performed to explore the factors influencing prognosis. ResultsEpilepsy surgery was performed on 44 infants with drug-resistant epilepsy, including 7 patients who underwent two operations. The age of seizure onset ranged from 1 day to 11 months (median: 1 month, interquartile range (IQR): 0.1–3.8), the disease course was 1–11 months (median: 4 months, IQR: 2–7), and the age at surgery was 6.9±3.6 months. Twenty-three patients underwent hemispherectomy (52.3%), and two underwent subtotal hemispherectomy. Five patients underwent multilobar disconnection, five underwent frontal lobotomy, and the remaining nine underwent focal resection. The surgical duration was 7.5±2 hours. Intraoperative blood loss ranged from 50–1800 ml (median: 275 ml, IQR: 200–500), with all patients receiving an intraoperative blood transfusion of 0.5–6 U (median: 1.5 U, IQR: 1.5–3). The intensive care unit stay was 1–4 days (median: 1 day, IQR: 1–2). The postoperative complication rate was 13.6% (6/44; two cases of hydrocephalus with intracranial infection, two isolated hydrocephalus, and two subdural hematomas). Excluding one child who died of severe lung infection approximately one year after surgery and one child lost to follow-up after surgery, all other cases were regularly followed up for 10 –49 months (median: 30 months, IQR: 16.5–36). After surgery, patients were treated with 0–3 ASMs (median: 1 ASM, IQR: 0–2); 27.9% (12/43) stopped taking ASMs and 51.2% (22/43) had reduced number of ASMs. Engel I was achieved in 76.7% (33/43) of the patients at the last follow-up. In 17 cases with complete developmental quotient follow-up data, the preoperative and postoperative developmental quotient means were 28.8±21 and 43.2±20.1, showing statistically significant differences (p<0.05) SignificanceEpilepsy surgery in infants under 12 months of age is safe and effective. Early preoperative evaluation is crucial for identifying structural lesions and suitable candidates for surgery among infants with drug-resistant epilepsy. The timeliness of surgery is essential for achieving favorable clinical outcomes.

The relationship between anti-seizures medications and metabolic acidosis in craniotomy operations: is topiramate or zonisamide the cause of metabolic acidosis?

Background/aimThe most commonly prescribed anti-seizures medications (ASMs) for the treatment of epilepsy are currently topiramate, zonisamide, lacosamide, carbamazepine and levetiracetam. The objective of this study was to examine the correlation between preoperative, intraoperative, and postoperative metabolic acidosis and the use of ASMs prior to craniotomy operations.Materials and methodsThis retrospective cross-sectional study evaluated patients who underwent intracranial surgery with craniotomy under general anaesthesia between May 2020 and April 2023 and used ASMs. The patients were classified into four groups based on the pharmacological mechanisms of action of the ASMs administered before intracranial surgery (Group-I, zonisamide or topiramate; Group-II, lacosamide; Group-III, carbamazepine; Group-IV, levetiracetam). Metabolic acidosis severity was defined based on base excess (BE) levels: mild (-3 to -5), moderate (-5 to -10), and severe (below − 10). The study investigated the correlation between ASMs and the severity of metabolic acidosis in preoperative, intraoperative, and postoperative blood gas measurements.ResultsOut of 35 patients, 24 patients underwent intracranial surgery and 11 patients underwent epilepsy surgery. There were statistically significant differences in the severity of metabolic acidosis between preoperative (p < 0.001), intraoperative (p < 0.001) and postoperative (p = 0.01) groups. The preoperative mean BE of group-I was − 4.7, which was statistically lower than that of group-III (p = 0.01) and group-IV (p < 0.001). Intraoperatively and postoperatively, group-I had a mean BE of -7.5 and − 3.2, respectively, which was statistically lower than that of groups II (p = 0.007; p = 0.04), III (p = 0.002; p = 0.03), and IV (p < 0.001; p = 0.009). There was no statistically significant difference in BE between groups II, III and IV at all three time points. Group I had the lowest BE at all three time points. Intraoperative bicarbonate was administered to all patients in group I, whereas no intraoperative bicarbonate was required in the other groups. In group I, 50% of patients required postoperative intensive care.ConclusionThe use of ASMs in patients undergoing surgery is important in terms of mortality and morbidity. Topirimat and zonisamide are ASMs that can cause preoperative, intraoperative and postoperative metabolic acidosis. Patients receiving topirimat or zonisamide are particularly susceptible to metabolic acidosis. Special care should be taken in the management of anaesthesia in patients receiving these drugs, and monitoring of the perioperative metabolic status is essential.

Higher Validity, Lower Radiation: A New Ictal Single-Photon Emission Computed Tomography Framework.

To assess whether arterial spin labeling perfusion images of healthy controls can enhance ictal single-photon emission computed tomography analysis and whether the acquisition of the interictal image can be omitted. We developed 2 pipelines: The first uses ictal and interictal images and compares these to single-photon emission computed tomography and arterial spin labeling of healthy controls. The second pipeline uses only the ictal image and the analogous healthy controls. Both pipelines were compared to the gold standard analysis and evaluated on data of individuals with epilepsy who underwent ictal single-photon emission computed tomography imaging during presurgical evaluation between 2010 and 2022. Fifty healthy controls prospectively underwent arterial spin labeling imaging. The correspondence between the detected hyperperfusion and the postoperative resection cavity or the presumably affected lobe was assessed using Dice score and mean Euclidean distance. Additionally, the outcomes of the pipelines were automatically assigned to 1 of 5 concordance categories. Inclusion criteria were met by 43 individuals who underwent epilepsy surgery and by 73 non-surgical individuals with epilepsy. Compared to the gold standard analysis, both pipelines resulted in significantly higher Dice scores and lower mean distances (p < 0.05). The combination of both provided localizing results in 85/116 cases, compared to 54/116 generated by the current gold standard analysis and the ictal image alone produced localizing results in 60/116 (52%) cases. We propose a new ictal single-photon emission computed tomography protocol; it finds relevantly more ictal hyperperfusion, and halves the radiation dose in about half of the individuals. ANN NEUROL 2024.

Hippocampal activations obtained during language fMRI tasks: A complementary tool for predicting postoperative memory prognosis

In medial temporal lobe epilepsy (MTLE), the benefits of surgery must be balanced against the risk of post-operative memory decline. Prediction of postoperative outcomes based on functional magnetic resonance imaging (fMRI) tasks is increasingly common but remains uncertain. The aim of this retrospective study was to determine whether hippocampal activations elicited by fMRI language tasks could enhance or refine memory fMRI in MTLE patients candidates to surgery. Forty-six patients were included: 30 right and 16 left MTLE, mostly with hippocampal sclerosis. Preoperative assessment included neuropsychological tests and fMRI with language (syntactic verbal fluency) and memory tasks (encoding, delayed, and immediate recognition of images of objects). Thirty patients underwent surgery and had neuropsychological evaluations one year after surgery. Worsening was defined as a degradation of more than 10 % in postoperative forgetting scores compared to preoperative scores in verbal, non-verbal and global memory. Memory fMRI had the best sensitivity with hippocampal activations obtained in 95 % of patients, versus 65 % with language fMRI. Considering the patients who elicited an hippocampal activation, language fMRI led to 80 %, 65 % and 85 % of correct predictions for respectively global, verbal and non verbal memory (versus 71 %, 64 % and 68 % with memory fMRI). Memory and language fMRI predictions outperformed those made by neuropsychological tests. In summary, language fMRI was less sensitive than memory fMRI to elicit hippocampal activations but when it did, the proportion of correct memory predictions was better. Moreover, it proved to be an independent predictive factor regardless of the side of the epileptic focus. Given the ease of setting up a language task in fMRI, we recommend the systematic combination of memory and language tasks to predict the post-operative memory outcome of MTLE patients undergoing epilepsy surgery.

Electrocorticographic Patterns in Frontal Epilepsy and Long-Term Outcomes [RETRACTED

The prognostic significance of tailored resection guided with intraoperative electrocorticography (iECoG) in frontal lobe epilepsy surgery has not been fully elucidated. To analyze influence of preresection and postresection iECoG patterns on long-term seizure control of adults with frontal lobe epilepsy undergoing epilepsy surgery. We retrospectively analyzed 27 patients undergoing epilepsy surgery from two centers with preresection and postresection iECoG and reported clinical variables, preresection and postresection iECoG patterns, and outcome using the Engel Outcome Scale. Descriptive statistics, Kaplan-Meier, the logistic regression model, and analysis of variance tests were used. Fifteen males (55.6%), a mean and mode follow-up after surgery of 43 (range 2-117) and 19 months, respectively. At 6 months, seizure frequency outcome according to Engel Scale was I 74.1% (20/27), II 7.4% (2/27), III 3.7% (1/27), and IV 14.8% (4/27). We found that 51.9% (14/27) and 40.8% (11/27) of patients without residual epileptiform discharges in postresective iECoG become seizure-free at 6 and 12 months of follow-up, respectively, compared with other postresective iECoG patterns. Disregarding the presence of lack of residual epileptiform discharges (interictal epileptiform discharges) after resection, Engel I outcome was seen between 74.1% and 63% at 6- and 12-month postresection follow-up, suggesting the outcome might be in relation with other factors.

Two-Year Follow-up Outcomes of Non-lesional Epilepsy Surgery in Iran

Background: Despite treatment with anti-epileptic drugs, 30% of epileptic patients continue to experience seizures, making surgery a viable option. Surgery has shown efficacy even in non-lesional epileptic individuals, although there is limited research on this topic. Objectives: This study aimed to investigate surgical outcomes in individuals with drug-resistant epilepsy (DRE) who undergo surgery despite having non-lesional magnetic resonance imaging (MRI) findings. Methods: This observational longitudinal study was conducted between 2017 and 2020 at a referral hospital in Tehran, Iran. Using census sampling, we screened 750 epilepsy cases and enrolled 80 patients (42 women and 38 men) with DRE and non-lesional MRI findings who underwent epilepsy surgery. We collected patients' demographics and seizure characteristics. A 2-year follow-up was conducted to assess the seizure freedom rate. We compared seizure-free and non-seizure-free patients who underwent temporal epilepsy surgery, extratemporal epilepsy surgery, corpus callosotomy, and Vagus nerve stimulation (VNS) using chi-square, Fisher exact, and binary logistic regression tests. Results: The seizure freedom rate was 62.7% for temporal surgery, 83.33% for extratemporal surgery, 26.66% for corpus callosotomy, and none for patients who underwent VNS. There was no difference between seizure-free and non-seizure-free patients in terms of their baseline characteristics, seizure semiology, lesion features, and post-operative findings (P-values &gt; 0.05), except that patients without a history of febrile convulsions tended to experience more seizure freedom after extratemporal surgery (P = 0.007). Additionally, older patients tended to experience more seizure freedom after temporal surgery (P = 0.03). Conclusions: This study underscores the potential benefits of epilepsy surgery in non-lesional DRE patients. Further research is needed to establish criteria for patient selection in this context.

Long-term seizure outcome after epilepsy surgery of neuroglial tumors

PurposeNeuroglial tumors are frequently associated with pharmacorefractory epilepsies. However, comprehensive knowledge about long-term outcomes after epilepsy surgery and the main prognostic factors for outcome is still limited. We sought to evaluate long-term outcomes and potential influencing factors in a large cohort of patients who underwent surgery for neuroglial tumors in a single-center setting.MethodsThe study analyzed the outcomes of 107 patients who underwent epilepsy surgery for neuroglial tumors between 2001 and 2020 at the Department of Epileptology, University Hospital Bonn, in Germany. The outcomes were evaluated using Engel classification. Differences in outcome related to potential prognostic factors were examined using the Chi2-test, Fisher’s exact test and sign test. Additionally, stepwise logistic regression analysis was employed to identify independent prognostic factors.ResultsComplete seizure freedom (Engel Class IA) was achieved in 75% of the operated patients at 12 months, and 56% at the last follow-up visit (70.4 ± 6.2 months, median: 40 months). Completeness of resection was a crucial factor for both 12-month follow-up outcomes and the longest available outcomes, whereas lobar tumor localization, histology (ganglioglioma vs. dysembryoplastic neuroepithelial tumor), history of bilateral tonic–clonic seizures prior to surgery, invasive diagnostics, side of surgery (dominant vs. non-dominant hemisphere), age at epilepsy onset, age at surgery, and epilepsy duration did not consistently impact postsurgical outcomes. Among temporal lobe surgeries, patients who underwent lesionectomy and lesionectomy, including hippocampal resection, demonstrated similar outcomes.ConclusionNeuroglial tumors present as excellent surgical substrates in treating structural epilepsy. To achieve an optimal postsurgical outcome, a complete lesion resection should be pursued whenever possible.

The value of linear and non-linear quantitative EEG analysis in paediatric epilepsy surgery: a machine learning approach

Epilepsy surgery is effective for patients with medication-resistant seizures, however 20–40% of them are not seizure free after surgery. Aim of this study is to evaluate the role of linear and non-linear EEG features to predict post-surgical outcome. We included 123 paediatric patients who underwent epilepsy surgery at Bambino Gesù Children Hospital (January 2009–April 2020). All patients had long term video-EEG monitoring. We analysed 1-min scalp interictal EEG (wakefulness and sleep) and extracted 13 linear and non-linear EEG features (power spectral density (PSD), Hjorth, approximate entropy, permutation entropy, Lyapunov and Hurst value). We used a logistic regression (LR) as feature selection process. To quantify the correlation between EEG features and surgical outcome we used an artificial neural network (ANN) model with 18 architectures. LR revealed a significant correlation between PSD of alpha band (sleep), Mobility index (sleep) and the Hurst value (sleep and awake) with outcome. The fifty-four ANN models gave a range of accuracy (46–65%) in predicting outcome. Within the fifty-four ANN models, we found a higher accuracy (64.8% ± 7.6%) in seizure outcome prediction, using features selected by LR. The combination of PSD of alpha band, mobility and the Hurst value positively correlate with good surgical outcome.

Mapping interictal discharges using intracranial EEG-fMRI to predict postsurgical outcomes.

Various subjective and objective methods have been proposed to identify which interictal epileptiform discharge (IED)-related EEG-fMRI results are more likely to delineate seizure generating tissue in patients with drug-resistant focal epilepsy for the purposes of surgical planning. In this intracranial EEG-fMRI study, we evaluated the utility of these methods to localize clinically relevant regions pre-operatively and compared the extent of resection of these areas to post-operative outcome. Seventy patients admitted for intracranial video-EEG monitoring were recruited for a simultaneous intracranial EEG-fMRI study. For all analyses of blood oxygen level-dependent responses associated with IEDs, an experienced epileptologist identified the most Clinically Relevant brain activation cluster using available clinical information. The Maximum cluster (the cluster with the highest z-score) was also identified for all analyses and assigned to one of three confidence levels (low, medium, or high) based on the difference of the peak z-scores between the Maximum and Second Maximum cluster (the cluster with the second highest peak z-value). The distance was measured and compared between the peak voxel of the aforementioned clusters and the electrode contacts where the interictal discharge and seizure onset were recorded. In patients who subsequently underwent epilepsy surgery, the spatial concordance between the aforementioned clusters and the area of resection was determined and compared to post-operative outcome. We evaluated 106 different IEDs in 70 patients. Both subjective (identification of the Clinically Relevant cluster) and objective (Maximum cluster much more significant than the second maximum cluster) methods of culling non-localizing EEG-fMRI activation maps increased the spatial concordance between these clusters and the corresponding IED or seizure onset zone contacts. However, only the objective methods of identifying medium and high confidence maps resulted in a significant association between resection of the peak voxel of the Maximum cluster and post-operative outcome. Resection of this area was associated with good post-operative outcomes but was not sufficient for seizure freedom. On the other hand, we found that failure to resect the medium and high confidence Maximum clusters was associated with a poor post-surgical outcome (negative predictive value = 1.0, sensitivity = 1.0). Objective methods to identify higher confidence EEG-fMRI results are needed to localize areas necessary for good post-operative outcomes. However, resection of the peak voxel within higher confidence Maximum clusters is not sufficient for good outcomes. Conversely, failure to resect the peak voxel in these clusters is associated with a poor post-surgical outcome.

Pediatric Palliative Epilepsy Surgery: A Report From the Pediatric Epilepsy Research Consortium (PERC) Surgery Database

BackgroundEpilepsy surgery is an underutilized resource for children with drug-resistant epilepsy. Palliative and definitive surgical options can reduce seizure burden and improve quality of life. Palliative epilepsy surgery is often seen as a “last resort” compared to definitive surgical options. We compare patient characteristics between palliative and definitive epilepsy surgical patients and present palliative surgical outcomes from the Pediatric Epilepsy Research Consortium surgical database. MethodsThe Pediatric Epilepsy Research Consortium Epilepsy Surgery database is a prospective registry of patients aged 0-18 years undergoing evaluation for epilepsy surgery at 20 pediatric epilepsy centers. We included all children with completed surgical therapy characterized as definitive or palliative. Demographics, epilepsy type, age of onset, age at referral, etiology of epilepsy, treatment history, time-to-referral/evaluation, number of failed anti-seizure medications (ASMs), imaging results, type of surgery, and postoperative outcome were acquired. ResultsSix hundred forty patients undergoing epilepsy surgery were identified. Patients undergoing palliative procedures were younger at seizure onset (median: 2.1 vs 4 years, P= 0.0008), failed more ASM trials before referral for presurgical evaluation (P=<0.0001), and had longer duration of epilepsy before referral for surgery (P=<0.0001). During presurgical evaluation, patients undergoing palliative surgery had shorter median duration of video-EEG data collected (P=0.007) but number of cases where ictal data were acquired was similar between groups. The most commonly performed palliative procedure was corpus callosotmy (31%), followed by lobectomy (21%) and neuromodulation (82% responsive neurostimulation vs 18% deep brain stimulation). Palliative patients were further categorized into traditionally palliative procedures vs traditionally definitive procedures. The majority of palliative patients had 50% reduction or better in seizure burden. Seizure free outcomes were significantly higher among those with traditional definitive surgeries, 41% (95% confidence interval: 26% to 57%) compared with traditional palliative surgeries and 9% (95% confidence interval: 2% to 17%). Rate of seizure freedom was 46% at 24 months or greater of follow-up in the traditional definitive group. ConclusionsPatients receiving palliative epilepsy surgery trialed more ASMs, were referred later after becoming drug resistant, and had longer gaps between drug resistance and epilepsy surgery compared with patients undergoing definitive epilepsy surgery. The extent of surgical evaluation is impacted if surgery is thought to be palliative. A majority of palliative surgery patients achieved >50% seizure reduction at follow-up, both in groups that received traditionally palliative and traditionally definitive surgical procedures. Palliative surgical patients can achieve greater seizure control and should be referred to an epilepsy surgery center promptly after failing two appropriate anti-seizure medications.

Naming assessment in bilinguals for epilepsy surgery-adaptation and standardization of Boston Naming Test in India

Purpose Naming difficulty is associated with temporal lobe epilepsy and a decline in naming ability is reported following dominant temporal lobe resections. The Boston Naming Test (BNT) is the most frequently used test for assessing naming ability. Evaluating naming ability in bilingual/multilingual populations is a challenge when participants are restricted to responding in one language. The study aimed to adapt and standardize the BNT as a valid clinical tool for evaluating bilingual/multilingual people undergoing epilepsy surgery in urban India. Results Culture-appropriate adaptations were done, and participants were allowed to respond in any language. Data from 197 participants showed a strong education effect. The adaptation showed strong internal consistency, reliability, construct validity, and high sensitivity to left temporal lobe epilepsy performance. Conclusions The adapted version that allowed for flexible use of more than one language is a useful clinical tool for evaluating bilingual people undergoing epilepsy surgery.

Long-term neuropsychological trajectories in children with epilepsy: does surgery halt decline?

Neuropsychological impairments are common in children with drug-resistant epilepsy. It has been proposed that epilepsy surgery might alleviate these impairments by providing seizure freedom; however, findings from prior studies have been inconsistent. We mapped long-term neuropsychological trajectories in children before and after undergoing epilepsy surgery, to measure the impact of disease course and surgery on functioning. We performed a retrospective cohort study of 882 children who had undergone epilepsy surgery at Great Ormond Street Hospital (1990-2018). We extracted patient information and neuropsychological functioning [obtained from IQ tests (domains: full-scale IQ, verbal IQ, performance IQ, working memory and processing speed) and tests of academic attainment (reading, spelling and numeracy)] and investigated changes in functioning using regression analyses. We identified 500 children (248 females) who had undergone epilepsy surgery [median age at surgery = 11.9 years, interquartile range = (7.8, 15.0)] and neuropsychological assessment. These children showed declines in all domains of neuropsychological functioning in the time leading up to surgery (all P-values ≤0.001; e.g. βFSIQ = -1.9, SEFSIQ = 0.3, PFSIQ < 0.001). Children lost on average one to four points per year, depending on the domain considered; 27%-43% declined by ≥10 points from their first to their last preoperative assessment. At the time of presurgical evaluation, most children (46%-60%) scored one or more standard deviations below the mean (<85) on the different neuropsychological domains; 37% of these met the threshold for intellectual disability (full-scale IQ < 70). On a group level, there was no change in performance from pre- to postoperative assessment on any of the domains (all P-values ≥0.128). However, children who became seizure free through surgery showed higher postoperative neuropsychological performance (e.g. rrb-FSIQ = 0.37, P < 0.001). These children continued to demonstrate improvements in neuropsychological functioning over the course of their long-term follow-up (e.g. βFSIQ = 0.9, SEFSIQ = 0.3, PFSIQ = 0.004). Children who had discontinued antiseizure medication treatment at 1-year follow-up showed an 8- to 13-point advantage in postoperative working memory, processing speed and numeracy, and greater improvements in verbal IQ, working memory, reading and spelling (all P-values ≤0.034) over the postoperative period compared with children who were seizure free and still receiving antiseizure medication. In conclusion, by providing seizure freedom and the opportunity for antiseizure medication cessation, epilepsy surgery might not only halt but reverse the downward trajectory that children with drug-resistant epilepsy display in neuropsychological functioning. To halt this decline as soon as possible or, potentially, to prevent it from occurring in the first place, children with focal epilepsy should be considered for epilepsy surgery as early as possible after diagnosis.

Incidence, Severity, and Risk Factors of Hemorrhagic Complications of Epilepsy Surgery After 2026 Craniotomies from 2003 to 2019: A Single Center Experience

Surgery is effective in the treatment of epilepsy, particularly focal epilepsy. The aim of this work was to report the incidence and grade of severity of hemorrhagic complications after cranial epilepsy surgery, and investigate the risk factors. Patients who underwent epilepsy surgery via craniotomy between October 2003 and April 2019 were retrospectively analyzed. The incidence of hemorrhagic complications occurring in a 3-month period after cranial surgery was recorded. Other outcomes included the grade of hemorrhagic severity and risk factors. During the inclusion period, 2026 surgical procedures were performed. Sixty-six hemorrhagic complications were recorded. The total incidence of hemorrhagic complications after cranial epilepsy surgery was 3.3%. The most common type of hemorrhagic complications was epidural hemorrhage (57.6%), followed by intraparenchymal hemorrhage (33.3%). Forty-five patients (68.2%) had grade I complications, 4 (6.1%) grade II, 16 (24.2%) grade III, and 1 (1.5%) grade IV. The mortality due to hemorrhagic complications was 1.5% (1 of 66) and hemorrhagic mortality among all cranial surgery was 0.05% (1 of 2026). Left craniotomy induced a higher percentage of severe hemorrhage than the right (34.2% vs. 14.3%). Extratemporal lobe epilepsy induced a higher percentage of severe hemorrhage than other epilepsy type (34.2% vs. 14.3%). However, no statistically significant difference was observed between these two factors (P= 0.067). Hemorrhagic complications were uncommon after open surgery for epilepsy. Most hemorrhagic complications were mild while the severe were rare. Patients with hemorrhagic complications had a good prognosis after effective treatment.

Management of Anti-seizure Medication in Patients with Drug-resistant Focal Epilepsy Secondary to Focal Cortical Dysplasia Undergoing Epilepsy Surgery in Argentina (P10-1.016)

Management of Anti-seizure Medication in Patients with Drug-resistant Focal Epilepsy Secondary to Focal Cortical Dysplasia Undergoing Epilepsy Surgery in Argentina (P10-1.016)

Epilepsy surgery in adults older than 50 years: A systematic review and meta-analysis.

Despite the general safety and efficacy of epilepsy surgery, there is evidence that epilepsy surgery remains underutilized. Although there are an increasing number of studies reporting epilepsy surgery in older adults, there is no consensus on whether epilepsy surgery is efficacious or safe for this population. Our objective was to systematically assess the efficacy as well as safety of resective surgery in people aged 50 years or older with drug-resistant epilepsy. We considered studies that examine the efficacy and safety of epilepsy surgery in adults aged 50 years and older. Study eligibility was limited to studies carried out after 1990, with a minimum of 10 participants and 6 months of follow-up. We searched the following databases for published studies: Ovid MEDLINE, Ovid Embase, Cumulative Index to Nursing and Allied Health Literature, PsychInfo, and Web of Science Conference Proceedings Citation Index - Science. The risk of bias of each included study was independently assessed by two reviewers using the MINORS (Methodological Index for Non-Randomized Studies) instrument. Eleven case series and 14 cohort studies met the criteria for inclusion, for a total of 1111 older adults who underwent epilepsy surgery along with 4111 adults younger than 50 years as control groups. The pooled cumulative incidence of older adults achieving seizure freedom after resective surgery was 70.1% (95% confidence interval [CI] = 65.3-74.7). There was no evident difference in the incidence of seizure freedom among older adults as compared to younger adults (risk ratio [RR] = 1.05, 95% CI = .97-1.14) in cohort studies. The pooled cumulative incidence of perioperative complications in older adults was 26.2% (95% CI = 21.3-31.7). Among them, 7.5% (95% CI = 5.8-9.5) experienced major complications. Older adults were significantly more at risk of experiencing any complication than younger adults (RR = 2.8, 95% CI = 1.5-5.4). Despite important considerations, epilepsy surgery may be considered appropriate among carefully selected individuals older than 50 years.