Dorfer, Christian

Abstract Objective There is a need to develop a comprehensive, formalized, and globally applicable epilepsy surgery curriculum in order to help standardize the quality of epilepsy surgery practice in the world. Methods The Epilepsy Surgery Educational Task Force of the ILAE developed a competency‐based epilepsy surgery educational curriculum comprised of four domains: Diagnosis, Counseling, Pre‐surgical Work‐up, and Surgical Techniques. To evaluate this educational curriculum, a survey questionnaire consisting of 11 items was sent out for feedback to ILAE and IESS members. The survey questionnaire asked respondents to rate the degree of importance of each competency on a five‐point scale that ranged from “extremely important” to “not at all important” and provided space for free text comments. All competencies that were rated as “slightly important” or “somewhat important” by more than 10% of responders, as well as all free text feedback comments, were fully reviewed, and the final curriculum was adjusted accordingly. Results One hundred and twenty‐two responses ( n = 122) were submitted by the ILAE and IESS communities. Seventy‐one percent (71.9%) of the responses came from neurosurgeons of varied experience and training levels. Ninety‐four percent (94.4%) of responders stated that they “support a curriculum to determine the competency of neurosurgeons participating in the care of people with epilepsy in my country,” and 94.3% confirmed that they “would be interested in taking or would recommend an ILAE course based on these competencies, that would provide an ILAE certificate of completion.” Relevant changes within the curriculum were made based on feedback. Significance The newly developed ILAE comprehensive epilepsy surgery educational curriculum has a high level of support from neurosurgeons and neurologists around the world and shows potential for broad acceptance and implementation.

Abstract Up to 80% of the world's population with epilepsy lives in low and middle‐income countries. Around one‐third of these patients will have drug‐resistant epilepsy, for which epilepsy surgery is an option. Unfortunately, many of these regions, as well as some more developed nations, lack sufficient epilepsy surgery units and trained neurosurgeons. With this in mind, the International League Against Epilepsy (ILAE) formed the Epilepsy Surgery Education Taskforce to address the shortage of further educational opportunities for surgeons and neurologists and to promote the creation of more epilepsy surgery units around the world. In this article, we publish our findings from a web‐based international survey, in which we investigated the global distribution and experience of neurosurgeons who perform epilepsy surgery, their educational paths, and opinions on the further need for epilepsy surgery education, as well as the resources available to them. We report a detailed analysis of the 202 survey replies received from 35 different countries across six continents. The lack of adequate numbers of epilepsy surgery units in the Southern Hemisphere is notable, and the aim of this task force with other ILAE committees, is to improve access to epilepsy surgery for patients and to enhance training for their health care providers.

AbstractObjectivesAlthough hemispheric surgeries are among the most effective procedures for drug‐resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1‐, 2‐, and 5‐years post‐hemispherectomy.MethodsRetrospective data of all pediatric patients with DRE and seizure outcome data from the original Hemispherectomy Outcome Prediction Scale (HOPS) study were included. The primary outcome of interest was time‐to‐seizure recurrence. A multivariate Cox proportional‐hazards regression model was developed to predict the likelihood of post‐hemispheric surgery seizure freedom at three time points (1‐, 2‐ and 5‐ years) based on a combination of variables identified by clinical judgment and inferential statistics predictive of the primary outcome. The final model from this study was encoded in a publicly accessible online calculator on the International Network for Epilepsy Surgery and Treatment (iNEST) website (https://hops‐calculator.com/).ResultsThe selected variables for inclusion in the final model included the five original HOPS variables (age at seizure onset, etiologic substrate, seizure semiology, prior non‐hemispheric resective surgery, and contralateral fluorodeoxyglucose–positron emission tomography [FDG‐PET] hypometabolism) and three additional variables (age at surgery, history of infantile spasms, and magnetic resonance imaging [MRI] lesion). Predictors of shorter time‐to‐seizure recurrence included younger age at seizure onset, prior resective surgery, generalized seizure semiology, FDG‐PET hypometabolism contralateral to the side of surgery, contralateral MRI lesion, non‐lesional MRI, non‐stroke etiologies, and a history of infantile spasms. The area under the curve (AUC) of the final model was 73.0%.SignificanceOnline calculators are useful, cost‐free tools that can assist physicians in risk estimation and inform joint decision‐making processes with patients and families, potentially leading to greater satisfaction. Although the HOPS data was validated in the original analysis, the authors encourage external validation of this new calculator.

AbstractObjectiveThis study was undertaken to determine whether the vertical parasagittal approach or the lateral peri‐insular/peri‐Sylvian approach to hemispheric surgery is the superior technique in achieving long‐term seizure freedom.MethodsWe conducted a post hoc subgroup analysis of the HOPS (Hemispheric Surgery Outcome Prediction Scale) study, an international, multicenter, retrospective cohort study that identified predictors of seizure freedom through logistic regression modeling. Only patients undergoing vertical parasagittal, lateral peri‐insular/peri‐Sylvian, or lateral trans‐Sylvian hemispherotomy were included in this post hoc analysis. Differences in seizure freedom rates were assessed using a time‐to‐event method and calculated using the Kaplan–Meier survival method.ResultsData for 672 participants across 23 centers were collected on the specific hemispherotomy approach. Of these, 72 (10.7%) underwent vertical parasagittal hemispherotomy and 600 (89.3%) underwent lateral peri‐insular/peri‐Sylvian or trans‐Sylvian hemispherotomy. Seizure freedom was obtained in 62.4% (95% confidence interval [CI] = 53.5%–70.2%) of the entire cohort at 10‐year follow‐up. Seizure freedom was 88.8% (95% CI = 78.9%–94.3%) at 1‐year follow‐up and persisted at 85.5% (95% CI = 74.7%–92.0%) across 5‐ and 10‐year follow‐up in the vertical subgroup. In contrast, seizure freedom decreased from 89.2% (95% CI = 86.3%–91.5%) at 1‐year to 72.1% (95% CI = 66.9%–76.7%) at 5‐year to 57.2% (95% CI = 46.6%–66.4%) at 10‐year follow‐up for the lateral subgroup. Log‐rank test found that vertical hemispherotomy was associated with durable seizure‐free progression compared to the lateral approach (p = .01). Patients undergoing the lateral hemispherotomy technique had a shorter time‐to‐seizure recurrence (hazard ratio = 2.56, 95% CI = 1.08–6.04, p = .03) and increased seizure recurrence odds (odds ratio = 3.67, 95% CI = 1.05–12.86, p = .04) compared to those undergoing the vertical hemispherotomy technique.SignificanceThis pilot study demonstrated more durable seizure freedom of the vertical technique compared to lateral hemispherotomy techniques. Further studies, such as prospective expertise‐based observational studies or a randomized clinical trial, are required to determine whether a vertical approach to hemispheric surgery provides superior long‐term seizure outcomes.

AbstractObjectiveTo develop and validate a model to predict seizure freedom in children undergoing cerebral hemispheric surgery for the treatment of drug‐resistant epilepsy.MethodsWe analyzed 1267 hemispheric surgeries performed in pediatric participants across 32 centers and 12 countries to identify predictors of seizure freedom at 3 months after surgery. A multivariate logistic regression model was developed based on 70% of the dataset (training set) and validated on 30% of the dataset (validation set). Missing data were handled using multiple imputation techniques.ResultsOverall, 817 of 1237 (66%) hemispheric surgeries led to seizure freedom (median follow‐up = 24 months), and 1050 of 1237 (85%) were seizure‐free at 12 months after surgery. A simple regression model containing age at seizure onset, presence of generalized seizure semiology, presence of contralateral 18‐fluoro‐2‐deoxyglucose–positron emission tomography hypometabolism, etiologic substrate, and previous nonhemispheric resective surgery is predictive of seizure freedom (area under the curve = .72). A Hemispheric Surgery Outcome Prediction Scale (HOPS) score was devised that can be used to predict seizure freedom.SignificanceChildren most likely to benefit from hemispheric surgery can be selected and counseled through the implementation of a scale derived from a multiple regression model. Importantly, children who are unlikely to experience seizure control can be spared from the complications and deficits associated with this surgery. The HOPS score is likely to help physicians in clinical decision‐making.