Surgical versus medical treatment of drug-resistant epilepsy: A systematic review and meta-analysis

Epilepsy surgery perceptions among general neurologists and epilepsy specialists: A survey

OBJECTIVE

Surgical intervention for drug-resistant epilepsy (DRE) is a safe and efficacious evidence-based treatment. Yet, neurologists have historically revealed hesitance in referring patients for surgical evaluations. The present study surveyed general neurologists and epilepsy specialists to assess their views and process in referring patients for specialized epilepsy care and epilepsy surgery.

METHODS

A 14-item survey assessing epilepsy referrals and views of epilepsy surgery was distributed to all neurologists currently practicing in a large national integrated health system using REDCap. Responses were qualitatively analyzed and differences between general neurologists and epileptologists were assessed using chi-squared tests.

RESULTS

In total, 100 responses were received from 67 general neurologists and 33 epileptologists with several similarities and differences emerging between the two groups. Both groups endorsed surgery and neuromodulation as treatment options in DRE, felt that seizure frequency rather than duration was relevant in considering epilepsy surgery, and indicated patient preference as the largest barrier limiting epilepsy surgery. General neurologists were more likely to require ≥ 3 ASMs to fail to diagnose DRE compared to epileptologists (45% vs. 15%, p < 0.01) who more often required ≥ 2 ASMs to fail. Epileptologists were also more likely than neurologists to try a new ASM (75.8% vs. 53.7%, p < 0.05) or optimize the current ASM (75.8% vs. 49.3%, p < 0.05) in DRE. General neurologists were more likely to consider epilepsy surgery to be less efficacious (p = 0.001) or less safe (p < 0.05).

SIGNIFICANCE

Overall, neurologists appear to have generally positive opinions of epilepsy surgery, which is a change from prior literature and represents a changing landscape of views toward this intervention. Furthermore, epileptologists and general neurologists endorsed more similarities than differences in their opinions of surgery and steps to referral, which is another encouraging finding. Those gaps that remain between epileptologists and general neurologists, particularly in standards of ASM prescription, may be addressed by more consistent education about DRE and streamlining of surgical referral procedures.

Association Between Magnetoencephalography-Localized Epileptogenic Zone, Surgical Resection Volume, and Postsurgical Seizure Outcome

PURPOSE

Surgical resection of magnetoencephalography (MEG) dipole clusters, reconstructed from interictal epileptiform discharges, is associated with favorable seizure outcomes. However, the relation of MEG cluster resection to the surgical resection volume is not known nor is it clear whether this association is direct and causal, or it may be mediated by the resection volume or other predictive factors. This study aims to clarify these open questions and assess the diagnostic accuracy of MEG in our center.

METHODS

We performed a retrospective cohort study of 68 patients with drug-resistant epilepsy who underwent MEG followed by resective epilepsy surgery and had at least 12 months of postsurgical follow-up.

RESULTS

Good seizure outcomes were associated with monofocal localization (χ2 = 6.94, P = 0.001; diagnostic odds ratio = 10.2) and complete resection of MEG clusters (χ2 = 22.1, P < 0.001; diagnostic odds ratio = 42.5). Resection volumes in patients with and without removal of MEG clusters were not significantly different (t = 0.18, P = 0.86; removed: M = 20,118 mm3, SD = 10,257; not removed: M = 19,566 mm3, SD = 10,703). Logistic regression showed that removal of MEG clusters predicts seizure-free outcome independent of the resection volume and other prognostic factors (P < 0.001).

CONCLUSIONS

Complete resection of MEG clusters leads to favorable seizure outcomes without affecting the volume of surgical resection and independent of other prognostic factors. MEG can localize the epileptogenic zone with high accuracy. MEG interictal epileptiform discharges mapping should be used whenever feasible to improve postsurgical seizure outcomes.

Outcomes after laser interstitial thermal ablation for temporal lobe epilepsy: a systematic review and meta-analysis

Epilepsy is a common condition that affects approximately 1% of the world's population, with about one-third being refractory epilepsy. Temporal lobe epilepsy is the most common type of drug-resistant epilepsy, and laser interstitial thermal therapy (LITT) is an innovative treatment. In this systematic review and meta-analysis, we aimed to summarize the current evidence on outcomes after LITT, including seizure freedom rate, complication rate, and neurocognitive outcome. PubMed and OVID Medline search engines were systematically searched for all indexed publications in the English language up to July15, 2023. The search was limited to human studies. Proportions and 95% confidence interval (CI) values were calculated for seizure, neurocognitive outcome, and complication rate. A total of 836 patients were included. Overall seizure outcomes, regardless of the pathology, included Engel I outcome in 56% (95% CI, 52.4-59.5%), Engel II outcome in 19.2% (95% CI, 15.4-23.6%), Engel III outcome in 17.3% (95% CI, 13.5-21.8%), and Engel IV outcome in 10.5% (95% CI 6.3-17%) of the patients. The overall decline in verbal and visual memory regardless of laterality was 24.2 (95% CI 8.6-52%) and 25.2% (8.3-55.8%). For naming, the decline was 13.4% (6.6-25.4%). The results of the pooled analysis in comparison with available data in the literature showed that seizure outcomes after LITT were slightly inferior to published data after temporal lobectomy. Data on cognitive outcomes after LITT are scarce and heterogeneous.

How are they doing as adults? Psychosocial and socioeconomic outcomes 11-30 years after pediatric epilepsy surgery

OBJECTIVE

Pediatric epilepsy surgery yields cure from epilepsy or complete seizure control with continued medication in many patients early in life. This study aimed to evaluate the long-term (>10 years) psychosocial and socioeconomic outcomes of pediatric epilepsy surgery and examine the role of comorbid disability, type of surgery, seizure freedom, and age at surgery.

METHODS

A novel ad hoc parent/patient questionnaire was used to assess educational and occupational attainment, marital/familial status, mobility, and other outcomes in patients who underwent unilobar or multilobar surgery for drug-refractory epilepsy during their childhood. The questionnaire also captured information on comorbid disability.

RESULTS

Of the 353 eligible patients, 203 could still be contacted and 101 of these (50%) returned appropriately filled-in questionnaires (follow-up intervals: 11-30 [mean: 19.6] years). The cure from epilepsy rate was 53%. Type of surgery was strongly confounded by comorbid disability. Patients with comorbid disabilities had significantly lower rates of regular school degrees, gainful employment, marriage, and driving license (N = 29; 12%, 4%, 0%, 3%) compared with non-disabled patients (N = 69; 89%, 80%, 43%, and 67%, respectively). Patients achieved lower school degrees than their siblings and parents. Non-disabled seizure-free patients had better employment and mobility outcomes compared with non-seizure-free patients. Age at surgery (<10 vs. ≥10 years of age) did not have any effect on any outcome in patients with preschool seizure onset.

SIGNIFICANCE

Pediatric epilepsy surgery can lead to permanent relief from epilepsy in many patients, but comorbid disability strongly impacts adult life achievement. In non-disabled patients, favorable outcomes in academic, occupational, marital, and mobility domains were achieved, approaching respective rates in the German population. Complete seizure freedom had additional positive effects on employment and mobility in this group. However, in case of chronic comorbid disability the overall life prospects may be limited despite favorable seizure outcomes.

Cost-effectiveness of surgical treatment compared to medical treatment in patients with drug-refractory epilepsy: A systematic review

BACKGROUND AND PURPOSE

Approximately 30% of epilepsy patients develop a drug-refractory epilepsy, that is, seizures cannot be controlled with antiepileptic drugs. Surgery has been evaluated as an effective but costly form of treatment. The aim of this systematic review is to synthesize the available evidence on the cost-effectiveness of surgical treatment compared to medical treatment for these patients.

METHOD

A systematic literature search was performed in MEDLINE, Embase, PsycINFO, Cochrane Library and the National Health Service Economic Evaluation Database until September 2022. Title, abstract and full-text screening were conducted by two researchers. Original studies published in English or German analyzing the cost-effectiveness of surgical compared to medical treatment were included. Study characteristics, effectiveness measures, costs and incremental cost-effectiveness ratios (ICERs) were extracted. The quality of studies was assessed using the Drummond checklist.

RESULTS

Fourteen studies were included. Most studies evaluated surgery as cost-effective. The ICER per patient seizure free ranged from dominant to purchasing power parity US dollars (PPP-USD) 479,275. The ICER per 1% seizure reduction ranged from PPP-USD 227 to PPP-USD 342. The ICER per year without seizures was PPP-USD 4202 and the ICER per quality-adjusted life-year ranged from dominant to PPP-USD 90,874. The studies varied greatly in their methodology and time horizon.

CONCLUSION

Surgical treatment is cost-effective compared to medical treatment, especially when a lifetime horizon is adopted. It is concluded that all disease-specific costs should be considered over a long period when assessing the cost-effectiveness of epilepsy treatment. From an economic perspective, efforts should be made to improve access to surgical treatment for patients with drug-refractory epilepsy.

Stereo-electroencephalography-guided radiofrequency thermocoagulation in patients with MRI-negative focal epilepsy

OBJECTIVE

Coupled with stereo-electroencephalography (SEEG), radiofrequency thermocoagulation (RFTC) has emerged as a therapeutic alternative for patients with refractory focal epilepsy, with proven safe but highly variable results across studies. The authors aimed to describe the outcomes and safety of SEEG-RFTC, focusing on patients with MRI-negative epilepsy.

METHODS

A retrospective observational study was conducted on patients evaluated by SEEG in the authors' center. Of 84 total cases, 55 underwent RFTC, with 31 MRI-negative epilepsies that were ultimately included in the study. The primary outcome was freedom from disabling seizures at last follow-up. Secondary outcomes were reduction in seizure frequency (RFTC response = seizure frequency reduction > 50%), peri-interventional complications, and neuropsychological outcomes. Potential factors influencing post-RFTC outcome were considered by comparing different variables between responders and nonresponders.

RESULTS

The mean follow-up period was 30.9 months (range 7.1-69.8 months). Three patients underwent subsequent resection/laser interstitial thermal therapy within the 1st year after RFTC failure. All other patients completed a minimum follow-up period of 1 year. Fourteen patients (45.2%) showed at least a 50% reduction in seizure frequency (responders), and 8 were seizure free (25.8% of the whole cohort). One case showed a permanent complication not directly related to thermolesions. Most patients (76%) showed no significant cognitive decline. Electrically elicited seizures (EESs) were observed in all seizure-free patients and were more frequent in responders (p = 0.038). All patients who were seizure free at the 6-month visit maintained their status during long-term follow-up.

CONCLUSIONS

SEEG-RFTC is a safe procedure and leads to a good response in many cases of MRI-negative focal epilepsies. One-quarter of the patients were seizure free and almost one-half were responders at the last follow-up. Although these results are still far from those achieved through conventional resection, a nonnegligible proportion of patients may benefit from this one-stage and much less invasive approach. Factors associated with seizure outcome remain to be elucidated; however, responders were significantly more frequent among patients with EESs, and achieving 6 months of seizure freedom appears to predict a good long-term response. In addition, the positive predictive value of RFTC response may be a valuable factor in the decision to proceed to subsequent surgery.

Clinical adult outcome 11-30 years after pediatric epilepsy surgery: Complications and other surgical adverse events, seizure control, and cure of epilepsy

OBJECTIVE

Pediatric epilepsy surgery promises seizure freedom or even cure of epilepsy. We evaluated the long-term (≥10 years) adult clinical outcome including surgery-related adverse events and complications, which are generally underreported.

METHODS

A monocentric, single-arm, questionnaire study in now adult patients who underwent epilepsy surgery during childhood. A novel ad hoc parental/patient questionnaire, which addressed diverse outcome domains was applied.

RESULTS

From a total of 353 eligible patients, 203 could be contacted (3 patients died of causes unknown) and 101 (50%) returned appropriately filled-in surveys. No evidence for a survey-response bias was found. The rate of surgical complications according to the patient records was 9%. As regards the survey, half of the parents/patients reported surgical adverse events (expected and unexpected issues) and one-third reported permanent aversive sequels. Two-thirds of the patients were seizure-free during the last year before follow-up; 63% were Engel class 1A; favorable seizure outcomes (including auras only) were obtained in 73%; and 54% were seizure-free and off antiseizure medicine (ASM), that is, cured of epilepsy. In non-seizure-free patients, seizure relapse occurred at any time during the follow-up interval but 87% of those with a seizure-free first postoperative year were seizure-free at follow-up. One patient experienced a seizure relapse during the ASM withdrawal trial but became seizure-free again with ASMs. Eleven patients reported an increased number of ASMs as compared to the time before surgery. Earlier focal surgery did not affect the long-term clinical outcome.

SIGNIFICANCE

Pediatric epilepsy surgery was capable of curing epilepsy in about one-half of the children and to significantly control seizures in about three-fourths. Long-term success of focal surgery did not depend on age at surgery or duration of epilepsy. Surgical adverse events including complications may be underreported and must be assessed more thoroughly.

Depiction of nervous system disorders in television medical drama: A content analysis of 18 seasons of Grey's Anatomy

BACKGROUND

Television medical dramas enjoy great popularity among the general public, and can be a source of information and misinformation about medical disorders. Nervous system disorders have always received attention in popular media, yet no studies have been performed to analyze their depiction and accuracy, to our knowledge.

OBJECTIVE

To investigate the representation of neurological and neurosurgical diseases in Grey's Anatomy, one of most popular and longest running primetime medical melodramas in American television.

METHODS

We performed a quantitative and qualitative content analysis of depictions of nervous system disorders in all 18 seasons of Grey's Anatomy, in addition to investigating the medical accuracy and the global quality of the portrayed medical content.

RESULTS

A total of 285 depictions were identified in 314 out of 400 episodes (78.5%) of Grey's Anatomy. Most of portrayed characters were males (59.2%), Caucasians (72.6%), and adults (76.4%), with a mean age of 32.6 ± 19.7 years for those mentioned. Most of the portrayals were of acute nature (65.5%), with neurosurgical diseases constituting the majority; 85.6%, while 31.6% depicted neurological diseases, and 19.3% had both. The most common clinical presentations were altered level of consciousness (16.5%) and seizures (14.4%). Traumatic brain injury was the most common portrayed diagnosis (39.3%), followed by brain tumors (13.7%), stroke (8.4%), and spinal injury (8.1%). Management was surgical for the majority of cases (79.6%), while only 17.9% received pharmacotherapy. The prognosis of portrayed cases was generally favorable, as 79.5% showed good/full recovery, while mortality rate was 18.6%. Forty cases (14.0%) were depictions of rare to very rare diseases. As regards to medical accuracy, 74.3% of depictions were deemed accurate within reason, with a mean GQS score of 4.38 ± 1.4. Four clinical trials involving the nervous system have been depicted throughout the show.

CONCLUSIONS

Neurosurgical and neurological diseases were portrayed in most episodes of Grey's Anatomy, with a good quality of its scientific content within reason. This study demonstrated that Grey's Anatomy had a good amount of medical information that could be able to improve the public perception of the specialty. However, there is still a room for significant improvement to acknowledge certain inaccuracies and misrepresentations in future episodes.

18F-FDG-PET hypometabolism as a predictor of favourable outcome in epilepsy surgery: protocol for a systematic review and meta-analysis

INTRODUCTION

A substantial proportion of patients who undergo surgery for drug resistant focal epilepsy do not become seizure free. While some factors, such as the detection of hippocampal sclerosis or a resectable lesion on MRI and electroencephalogram-MRI concordance, can predict favourable outcomes in epilepsy surgery, the prognostic value of the detection of focal hypometabolism with ¹⁸F-fluorodeoxyglucose positive emission tomography (¹⁸F-FDG-PET) hypometabolism is uncertain. We propose a protocol for a systematic review and meta-analysis to examine whether localisation with ¹⁸F-FDG-PET hypometabolism predicts favourable outcomes in epilepsy surgery.

METHODS AND ANALYSIS

A systematic literature search of Medline, Embase and Web of Science will be undertaken. Publications which include evaluation with ¹⁸F-FDG-PET prior to surgery for drug resistant focal epilepsy, and which report ≥12 months of postoperative surgical outcome data will be included. Non-human, non-English language publications, publications with fewer than 10 participants and unpublished data will be excluded. Screening and full-text review of publications for inclusion will be undertaken by two independent investigators, with discrepancies resolved by consensus or a third investigator. Data will be extracted and pooled using random effects meta-analysis, with heterogeneity quantified using the I² analysis.

ETHICS AND DISSEMINATION

Ethics approval is not required. Once complete, the systematic review will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022324823.

Implementation of a Morphological Filter for Removing Spikes from the Epileptic Brain Signals to Improve Identification Ripples

Epilepsy is a very common disease affecting at least 1% of the population, comprising a number of over 50 million people. As many patients suffer from the drug-resistant version, the number of potential treatment methods is very small. However, since not only the treatment of epilepsy, but also its proper diagnosis or observation of brain signals from recordings are important research areas, in this paper, we address this very problem by developing a reliable technique for removing spikes and sharp transients from the baseline of the brain signal using a morphological filter. This allows much more precise identification of the so-called epileptic zone, which can then be resected, which is one of the methods of epilepsy treatment. We used eight patients with 5 KHz data set and depended upon the Staba 2002 algorithm as a reference to detect the ripples. We found that the average sensitivity and false detection rate of our technique are significant, and they are ∼94% and ∼14%, respectively.

Next-Generation Personalized Medicine: Implementation of Variability Patterns for Overcoming Drug Resistance in Chronic Diseases

Chronic diseases are a significant healthcare problem. Partial or complete non-responsiveness to chronic therapies is a significant obstacle to maintaining the long-term effect of drugs in these patients. A high degree of intra- and inter-patient variability defines pharmacodynamics, drug metabolism, and medication response. This variability is associated with partial or complete loss of drug effectiveness. Regular drug dosing schedules do not comply with physiological variability and contribute to resistance to chronic therapies. In this review, we describe a three-phase platform for overcoming drug resistance: introducing irregularity for improving drug response; establishing a deep learning, closed-loop algorithm for generating a personalized pattern of irregularity for overcoming drug resistance; and upscaling the algorithm by implementing quantified personal variability patterns along with other individualized genetic and proteomic-based ways. The closed-loop, dynamic, subject-tailored variability-based machinery can improve the efficacy of existing therapies in patients with chronic diseases.

Functional Connectivity Alterations Based on Hypometabolic Region May Predict Clinical Prognosis of Temporal Lobe Epilepsy: A Simultaneous 18F-FDG PET/fMRI Study

(1) Background: Accurate localization of the epileptogenic zone and understanding the related functional connectivity (FC) alterations are critical for the prediction of clinical prognosis in patients with temporal lobe epilepsy (TLE). We aim to localize the hypometabolic region in TLE patients, compare the differences in FC alterations based on hypometabolic region and structural lesion, respectively, and explore their relationships with clinical prognosis. (2) Methods: Thirty-two TLE patients and 26 controls were recruited. Patients underwent 18F-FDG PET/MR scan, surgical treatment, and a 2−3-year follow-up. Visual assessment and voxel-wise analyses were performed to identify hypometabolic regions. ROI-based FC analyses were performed. Relationships between clinical prognosis and FC values were performed by using Pearson correlation analyses and receiver operating characteristic (ROC) analysis. (3) Results: Hypometabolic regions in TLE patients were found in the ipsilateral hippocampus, parahippocampal gyrus, and temporal lobe (p < 0.001). Functional alterations based on hypometabolic regions showed a more extensive whole-brain FC reduction. FC values of these regions negatively correlated with epilepsy duration (p < 0.05), and the ROC curve of them showed significant accuracy in predicting postsurgical outcome. (4) Conclusions: In TLE patients, FC related with hypometabolic region obtained by PET/fMRI may provide value in the prediction of disease progression and seizure-free outcome.

fMRI-Based Effective Connectivity in Surgical Remediable Epilepsies: A Pilot Study

Simultaneous EEG-fMRI can contribute to identify the epileptogenic zone (EZ) in focal epilepsies. However, fMRI maps related to Interictal Epileptiform Discharges (IED) commonly show multiple regions of signal change rather than focal ones. Dynamic causal modeling (DCM) can estimate effective connectivity, i.e. the causal effects exerted by one brain region over another, based on fMRI data. Here, we employed DCM on fMRI data in 10 focal epilepsy patients with multiple IED-related regions of BOLD signal change, to test whether this approach can help the localization process of EZ. For each subject, a family of competing deterministic, plausible DCM models were constructed using IED as autonomous input at each node, one at time. The DCM findings were compared to the presurgical evaluation results and classified as: "Concordant" if the node identified by DCM matches the presumed focus, "Discordant" if the node is distant from the presumed focus, or "Inconclusive" (no statistically significant result). Furthermore, patients who subsequently underwent intracranial EEG recordings or surgery were considered as having an independent validation of DCM results. The effective connectivity focus identified using DCM was Concordant in 7 patients, Discordant in two cases and Inconclusive in one. In four of the 6 patients operated, the DCM findings were validated. Notably, the two Discordant and Invalidated results were found in patients with poor surgical outcome. Our findings provide preliminary evidence to support the applicability of DCM on fMRI data to investigate the epileptic networks in focal epilepsy and, particularly, to identify the EZ in complex cases.

A meta-analysis on potential modifiers of LITT efficacy for mesial temporal lobe epilepsy: Seizure-freedom seems to fade with time

BACKGROUND

The efficacy of laser interstitial thermal therapy (LITT) in mesial temporal lobe epilepsy (MTLE) has not been clearly established yet.

OBJECTIVE

We conducted a meta-analysis to estimate the efficacy of LITT for TLE (Q1). We also examined the effect of the patient's age (Q2), the total ablation volume (TAV) (Q3), the strength of the MRI unit (Q4), the type of the utilized stereotactic platform (Q5), and the follow up period (Q6) on the patient's outcome.

METHODS

Fixed- and random-effects model meta-analysis was conducted to assess the proportion estimate for each parameter individually. Kaplan-Meier survival-analysis was performed on the available individual patient time-to-first seizure data.

RESULTS

Sixteen studies with 575 patients fulfilled our eligibility criteria. The efficacy of LITT was 0.547 (95%CI: 0.506-0.588). Our statistical analysis had robust results after stratification according to the study population (Q2; p = 0.3418), and the type of the utilized stereotactic platform (Q5; p = 0.286), whereas the role of the TAV (Q3; p = 0.058) and strength of the magnetic field (Q4; p = 0.062) in seizure control remained unclear. The median seizure-free period (Q6) was 0.643 (0.569-0.726) and 0.467 (0.385-0.566) for the one- and the two-year follow up.

CONCLUSIONS

LITT seems to offer a viable alternative to resective surgery, with a moderate efficacy and enduring results. Higher ablation volumes may be associated with improved seizure control, although our current study provided no statistically significant data. More high-quality studies are required to highlight the role of LITT in epilepsy surgery, particularly in the pediatric population.

Facial memory ability and self-awareness in patients with temporal lobe epilepsy after anterior temporal lobectomy

Anterior temporal lobectomy (ATL) is the most common surgical treatment for drug-resistant temporal lobe epilepsy (TLE). Right ATL has been reported to reduce facial memory ability in patients with TLE, as indicated by poor performance on the Warrington Recognition Memory Test for Faces (RMF), which is commonly used to evaluate visual memory in these patients. However, little is known about whether patients with TLE exhibit difficulties in identifying faces in daily life after ATL. The aim of this study was to investigate facial memory ability and self-awareness of face identification difficulties in patients with TLE after ATL. Sixteen patients with TLE after right ATL, 14 patients with TLE after left ATL, and 29 healthy controls were enrolled in this study. We developed the multiview face recognition test (MFRT), which comprises a learning phase (one or three frontal face images without external facial feature information) and a recognition phase (frontal, oblique, or noise-masked face images). Facial memory abilities were examined in all participants using the MFRT and RMF, and self-awareness of difficulties in face identification was evaluated using the 20-item prosopagnosia index (PI20), which has been widely used to assess developmental prosopagnosia. The MFRT performance in patients with TLE after ATL was significantly worse than that in healthy controls regardless of the resected side, whereas the RMF scores in patients with TLE were significantly worse than those in healthy controls only after right ATL. The MFRT performance in patients with TLE after both left and right ATL was more influenced by working memory load than that in healthy controls. The PI20 scores revealed that patients with TLE after left ATL were aware of their difficulties in identifying faces. These findings suggest that patients with TLE not only after right ATL but also after left ATL might have difficulties in face identification.

Efficient automated localization of ECoG electrodes in CT images via shape analysis

Purpose

People with drug-refractory epilepsy are potential candidates for surgery. In many cases, epileptogenic zone localization requires intracranial investigations, e.g., via ElectroCorticoGraphy (ECoG), which uses subdural electrodes to map eloquent areas of large cortical regions. Precise electrodes localization on cortical surface is mandatory to delineate the seizure onset zone. Simple thresholding operations performed on patients’ computed tomography (CT) volumes recognize electrodes but also other metal objects (e.g., wires, stitches), which need to be manually removed. A new automated method based on shape analysis is proposed, which provides substantially improved performances in ECoG electrodes recognition.

Methods

The proposed method was retrospectively tested on 24 CT volumes of subjects with drug-refractory focal epilepsy, presenting a large number (> 1700) of round platinum electrodes. After CT volume thresholding, six geometric features of voxel clusters (volume, symmetry axes lengths, circularity and cylinder similarity) were used to recognize the actual electrodes among all metal objects via a Gaussian support vector machine (G-SVM). The proposed method was further tested on seven CT volumes from a public repository. Simultaneous recognition of depth and ECoG electrodes was also investigated on three additional CT volumes, containing penetrating depth electrodes.

Results

The G-SVM provided a 99.74% mean classification accuracy across all 24 single-patient datasets, as well as on the combined dataset. High accuracies were obtained also on the CT volumes from public repository (98.27% across all patients, 99.68% on combined dataset). An overall accuracy of 99.34% was achieved for the recognition of depth and ECoG electrodes.

Conclusions

The proposed method accomplishes automated ECoG electrodes localization with unprecedented accuracy and can be easily implemented into existing software for preoperative analysis process. The preliminary yet surprisingly good results achieved for the simultaneous depth and ECoG electrodes recognition are encouraging.

Ethical approval n°NCT04479410 by “IRCCS Neuromed” (Pozzilli, Italy), 30th July 2020.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11548-021-02325-0.

Pediatric Epilepsy Surgery in Focal and Generalized Epilepsy: Current Trends and Recent Advancements

For a subset of children with medically intractable epilepsy, surgery may provide the best chances of seizure freedom. Whereas the indications for epilepsy surgery are commonly thought to be limited to patients with focal epileptogenic foci, modern imaging and surgical interventions frequently permit successful surgical treatment of generalized epilepsy. Resection continues to be the only potentially curative intervention; however, the advent of various neuromodulation interventions provides an effective palliative strategy for generalized or persistent seizures. Although the risks and benefits vary greatly by type and extent of intervention, the seizure outcomes appear to be uniformly favorable. Advances in both resective and nonresective surgical interventions provide promise for improved seizure freedom, function, and quality of life. This review summarizes the current trends and recent advancements in pediatric epilepsy surgery from diagnostic workup and indications through surgical interventions and postoperative outcomes.

Comparison of clinical efficacy of oxcarbazepine and lamotrigine combined with escitalopram, and impact on prognostic quality of life in treating patients with epilepsy and depressive disorder

This study aimed to investigate the clinical efficacy of oxcarbazepine and lamotrigine combined with escitalopram in treating patients with epilepsy and depressive disorder, and their influence on the prognostic quality of life. A total of 108 patients with epilepsy and depression were selected as research participants. Among them, 53 patients were treated by oxcarbazepine combined with escitalopram (group A) and 55 patients were treated by lamotrigine combined with escitalopram (group B). Following six-month treatment, efficacy, epilepsy frequency and duration, Hamilton Depression Rating (HAMD) and Montgomery-Asberg Depression Rating (MADRS) scores, adverse reactions, improvement of electroencephalogram (EEG) epileptic discharge, quality of life, 1-year drug retention rate and withdrawal reasons of the two groups were compared. There was no remarkable difference in the total efficacy rate between both groups. The number and duration of epileptic seizures, improvement of EEG epileptic discharge and quality of life in the two groups significantly improved after treatment, with no marked difference. HAMD and MADRS scores of patients from group B were significantly lower after treatment compared with those of patients from group A. The incidence rate of adverse reactions in group B was dramatically lower compared with group A, and the 1-year drug retention rate of group B was dramatically higher compared with that in group A. Both oxcarbazepine and lamotrigine combined with escitalopram exhibited good efficacy in patients with epilepsy and depressive disorder, and they may effectively improve the prognostic quality of life of patients. Lamotrigine combined with escitalopram presented with a better antidepressant effect and safety, with higher patient tolerance.

Contralateral Preoperative Resting-State Functional MRI Network Integration Is Associated with Surgical Outcome in Temporal Lobe Epilepsy

Background Although most patients with medically refractory temporal lobe epilepsy (TLE) experience seizure freedom after anterior temporal lobectomy, approximately 40% may continue to have seizures. Functional network integration, as measured with preoperative resting-state functional MRI, may help stratify patients who are more likely to experience postoperative seizure freedom. Purpose To relate preoperative resting-state functional MRI and surgical outcome in patients with medically refractory TLE. Materials and Methods Data from patients with medically intractable TLE were retrospectively analyzed. Patients underwent preoperative resting-state functional MRI between March 2010 and April 2013 and subsequent unilateral anterior temporal lobectomy. Postoperative seizure-free status was categorized using the Engel Epilepsy Surgery Outcome Scale. Global and regional resting-state functional MRI network properties on preoperative functional MRI scans related to integration were calculated and statistically compared between patients who experienced complete postoperative seizure freedom (Engel class IA) and all others (Engel class IB to class IV) using t tests and multiple logistic regression. Results Forty patients (mean age, 34 years ± 15 [standard deviation]; 21 female) were evaluated. Preoperative global network integration was different (P = .01) between patients who experienced seizure freedom after surgery and all other patients, with 9% lower leaf fraction and 10% lower tree hierarchy in patients with ongoing seizures. Preoperative regional network integration in the contralateral temporoinsular region was different (P = .04) between patients in these two groups. Specifically, the group-level leaf proportion was 59% lower in the entorhinal cortex, 73% lower in the inferior temporal gyrus, 43% lower in the temporal pole, and 69% lower in the insula in patients with ongoing seizures after surgery. When using multivariate regression, contralateral temporoinsular leaf proportion (P = .002) and epilepsy duration (P = .04) were predictive of postoperative seizure freedom, while age (P > .70) and age at seizure onset (P > .50) were not. Conclusion Lower network integration globally and involving the contralateral temporoinsular cortex on preoperative resting-state functional MRI scans is associated with ongoing postoperative seizures in patients with temporal lobe epilepsy. © RSNA, 2020.

Parents' view of the cognitive outcome one year after pediatric epilepsy surgery

OBJECTIVES

The cognitive outcome of pediatric epilepsy surgery has mainly been examined on the basis of standardized tests. Here, we analyzed the outcome in six cognitive domains from the parents' view.

METHODS

Included were consecutive surgical pediatric patients whose parents filled-in a comprehensive questionnaire on cognitive problems in children and adolescents (Kognitive Probleme bei Kindern und Jugendlichen (KOPKIJ); Gleissner et al. 2006) at the preoperative baseline (T1) as well as twelve months thereafter (T2). All children also underwent standard neuropsychological assessments at T1 and T2.

RESULTS

Parents of 96 patients provided pre- and postoperative KOPKIJ data. Overall, 80% of the children became seizure-free at the follow-up. Group means indicated a strong positive effect of time on KOPKIJ and neuropsychological performance. We found postoperative improvements in five out of six cognitive domains (language, memory, executive functions, attention, school; unchanged: visuospatial abilities). Individually, improvements were twice as likely as declines. However, 33 patients (35%) experienced significant decline in at least one cognitive domain. Later onset of epilepsy resulted in better performance but had no effect on change scores. Seizure-free status, lower antiseizure drug load, and stronger drug reduction after surgery contributed to postoperative cognitive improvements as perceived by the parents; no other effects of clinical factors were obtained (e.g., localization/lateralization). Despite their similar outcome patterns, change scores as derived from parental ratings and neuropsychological assessment were not correlated.

CONCLUSIONS

Parents acknowledged the overall positive neurocognitive development after pediatric epilepsy surgery as previously shown by standardized tests. Seizure freedom and lower antiseizure drug load contributed to the beneficial cognitive outcome. Even if cognitive improvements outweighed declines, a risk for cognitive decline with impact on everyday functioning does exist.

Neural stimulation systems for the control of refractory epilepsy: a review

Epilepsy affects nearly 1% of the world's population. A third of epilepsy patients suffer from a kind of epilepsy that cannot be controlled by current medications. For those where surgery is not an option, neurostimulation may be the only alternative to bring relief, improve quality of life, and avoid secondary injury to these patients. Until recently, open loop neurostimulation was the only alternative for these patients. However, for those whose epilepsy is applicable, the medical approval of the responsive neural stimulation and the closed loop vagal nerve stimulation systems have been a step forward in the battle against uncontrolled epilepsy. Nonetheless, improvements can be made to the existing systems and alternative systems can be developed to further improve the quality of life of sufferers of the debilitating condition. In this paper, we first present a brief overview of epilepsy as a disease. Next, we look at the current state of biomarker research in respect to sensing and predicting epileptic seizures. Then, we present the current state of open loop neural stimulation systems. We follow this by investigating the currently approved, and some of the recent experimental, closed loop systems documented in the literature. Finally, we provide discussions on the current state of neural stimulation systems for controlling epilepsy, and directions for future studies.

[Prognosis for surgical treatment of pharmacoresistant epilepsy: the role of mental and cognitive disorders]

This review focuses on the role of mental and cognitive disorders in the prognosis for surgical treatment of pharmacoresistant epilepsy. The authors analyze historical aspects of the surgical treatment of epilepsy and present current data on the prognosis of operative intervention with respect to seizure control, cognitive functioning, and psychiatric disorders. The psychiatrist's role in the structure of preoperative and postoperative management of patients is considered.

Stereoelectroencephalography Versus Subdural Electrodes for Localization of the Epileptogenic Zone: What Is the Evidence?

Accurate and safe localization of epileptic foci is the crux of surgical therapy for focal epilepsy. As an initial evaluation, patients with drug-resistant epilepsy often undergo evaluation by noninvasive methods to identify the epileptic focus (i.e., the epileptogenic zone (EZ)). When there is incongruence of noninvasive neuroimaging, electroencephalographic, and clinical data, direct intracranial recordings of the brain are often necessary to delineate the EZ and determine the best course of treatment. Stereoelectroencephalography (SEEG) and subdural electrodes (SDEs) are the 2 most common methods for recording directly from the cortex to delineate the EZ. For the past several decades, SEEG and SDEs have been used almost exclusively in specific geographic regions (i.e., France and Italy for stereo-EEG and elsewhere for SDEs) for virtually the same indications. In the last decade, however, stereo-EEG has started to spread from select centers in Europe to many locations worldwide. Nevertheless, it is still not the preferred method for invasive localization of the EZ at many centers that continue to employ SDEs exclusively. Despite the increased dissemination of the SEEG method throughout the globe, important questions remain unanswered. Which method (SEEG or SDEs) is superior for identification of the EZ and does it depend on the etiology of epilepsy? Which technique is safer and does this hold for all patient populations? Should these 2 methods have equivalent indications or be used selectively for different focal epilepsies? In this review, we seek to address these questions using current invasive monitoring literature. Available meta-analyses of observational data suggest that SEEG is safer than SDEs, but it is less clear from available data which method is more accurate at delineating the EZ.

Cortical GABAergic Interneuron/Progenitor Transplantation as a Novel Therapy for Intractable Epilepsy

Epilepsy is a severe neurological disease affecting more than 70 million people worldwide that is characterized by unpredictable and abnormal electrical discharges resulting in recurrent seizures. Although antiepileptic drugs (AEDs) are the mainstay of epilepsy treatment for seizure control, about one third of patients with epilepsy suffer from intractable seizures that are unresponsive to AEDs. Furthermore, the patients that respond to AEDs typically experience adverse systemic side effects, underscoring the urgent need to develop new therapies that target epileptic foci rather than more systemic interventions. Neurosurgical removal of affected brain tissues or implanting neurostimulator devices are effective options only for a fraction of patients with drug-refractory seizures, so it is imperative to develop treatments that are more generally applicable and restorative in nature. Considering the abnormalities of GABAergic inhibitory interneurons in epileptic brain tissues, one strategy with considerable promise is to restore normal circuit function by transplanting GABAergic interneurons/progenitors into the seizure focus. In this review, we focus on recent studies of cortical GABAergic interneuron transplantation to treat epilepsy and discuss critical issues in moving this promising experimental therapeutic treatment into clinic.