Ostendorf, Adam P.

Abstract Objective Surgery is an effective, yet underutilized treatment for children with drug‐resistant epilepsy. Although predictors of surgical outcomes are well described, the decision to recommend surgery varies by institution. We aim to evaluate the rates of not recommending surgery, identify associated patient characteristics, and quantify variability across centers. Methods We queried the Pediatric Epilepsy Research Consortium Surgery database, a prospective multicenter cohort of children (0–18 years) undergoing initial evaluation for epilepsy surgery. Patients with documented surgical decisions were included. Demographic, clinical, and presurgical evaluation variables were compared by surgical recommendation status. Logistic regression identified factors associated with not recommending surgery. Mixed‐effects models quantified between‐center variability. Results Among 2480 patients across 29 centers, 532 (21%) were not recommended epilepsy surgery (median center rate 17%, interquartile range [IQR] 10%–28%). After accounting for patient characteristics associated with surgical candidacy, substantial variation in decision‐making remained across centers, with a median twofold difference in the odds of not recommending surgery between otherwise similar patients evaluated at different institutions (Median Odds Ratio = 2.25; Intraclass Correlation Coefficient = .18). The clinical characteristics most strongly associated with not recommending surgery included monthly or less frequent seizures (odds ratio [OR] 2.17, 95% confidence interval [CI] 1.75–2.69), non‐structural etiology (OR 2.02, 95% CI 1.56–2.61), and taking ≤2 anti‐seizure medications (ASMs) (OR 1.67, 95% CI 1.34–2.08, all p 's < .01). These characteristics showed minimal clustering across centers (ICCs < .05). Significance One in five children evaluated for epilepsy surgery are not recommended to pursue surgical treatment. Although clinical factors influence decision‐making, they do not explain the substantial variation in recommendations across pediatric epilepsy centers. Similar children evaluated at different institutions had significant differences in the odds of not being recommended surgery, suggesting that institutional decision‐making contributes importantly to surgical candidacy.

Abstract Objective Epilepsy duration is a modifiable risk factor in the outcome of definitive epilepsy surgery; however, an analogous effect in palliative procedures has not been shown. We reviewed the Pediatric Epilepsy Surgery Database data for an association between epilepsy duration and seizure reduction in palliative procedures. Methods Patients enrolled between January 2018 and April 2025 who underwent their first epilepsy surgery with palliative intent with 6 months of follow‐up were included. Procedures included neuromodulation, corpus callosotomy, hemispherotomy, lesionectomy, and lobectomy where surgical intent was not seizure freedom. Outcomes of seizure freedom, 90% seizure reduction, and 50% seizure reduction were considered at 6–12 months and >12 months from surgery. Duration from epilepsy onset to surgery was compared for patients above and below each outcome threshold at each time point. Logistic regression analysis for the association between epilepsy duration and seizure reduction adjusted for potential confounders including procedure type, etiology, and other clinical factors. Logistic regression analysis was performed on the overall cohort and subgroups of patients with each procedure. Results A total of 588 patients were included. Initial univariate analysis suggested that epilepsy duration at time of surgery was significantly associated with seizure freedom and 90% seizure reduction at both 6–12 months and >12 months. After adjusting for confounders, only seizure freedom at >12 months was significantly associated with duration of epilepsy. When individual procedures were considered, only lobectomy was sensitive to duration of epilepsy in multivariate analysis, with significant impacts on >50% and >90% seizure reduction at >12 months. Lesional epilepsy predicted seizure freedom at >12 months. Neuromodulation and corpus callosotomy were less likely to achieve seizure reduction than other procedures. Significance We did not find an association between early epilepsy surgery and seizure reduction. This reflects the heterogeneity of our population, including different types of surgical procedures and lesional and nonlesional epilepsies.

Abstract Objective Despite being safe and effective, surgery for pediatric epilepsy is underutilized. Social determinants of health (SDoH) are important to consider when examining this treatment gap. This study examined the potential systemic inequities at three different stages in the journey toward epilepsy surgery across the Pediatric Epilepsy Research Consortium (PERC). Methods Any youth in the PERC prospective surgery database (≤18 years) was eligible and included if sociodemographic factors were also available. We examined if there were differences in disparity factors in: (1) referral to Phase I evaluation, (2) offering of surgery, and (3) completion of surgery. Results Of 1309 patients, the majority were male (53%, p = .04), White (82.2%, p < .001), not Hispanic or Latino (84.3%, p < .001), and privately insured (56.3%, p < .001). Of the youth who were offered surgical treatment ( n = 1103, 84.3%), there were no significant differences in race/ethnicity or sex. Those with a structural lesion were more likely to be offered surgery, and historically marginalized youth were more likely to have a lesion. Of patients who completed surgery ( n = 927, 84.0%), White patients were 1.88 times (95% confidence interval [CI]: 1.14–3.04) more likely than Black patients to complete surgery ( p = .01). Significance Youth who began surgery evaluation are not representative of the demographics of those with epilepsy in the United States, with greater representation of White, non‐Hispanic male individuals. In addition, youth who began surgery evaluation disproportionally have private insurance. At the next stage of offering surgery, there were no differences based on SDoH. However, there is evidence that underrepresented youth that were magnetic resonance negative were less likely to be referred for surgical workup and that Black youth were less likely to undergo surgery. Therefore, efforts to provide equitable opportunity for all youth with refractory epilepsy should be concentrated at the referral for surgery evaluation point of care; however, additional efforts are also needed at later stages.

ABSTRACT Rationale Longer duration of epilepsy before surgery is a predictor of poor outcome. While referral delays of surgical candidates are well documented, factors causing delay during the presurgical evaluation remain unclear and may vary depending on institutional characteristics. By benchmarking the duration of presurgical evaluation across multiple centers and identifying patient and evaluation characteristics contributing to duration, we can ascertain best practices and address modifiable contributors to reduce delays. Methods We queried the Pediatric Epilepsy Research Consortium Surgery Database, a prospective, observational multicenter study enrolling children 0–18 years at 27 US pediatric epilepsy centers, for all patients undergoing initial presurgical evaluation for drug‐resistant epilepsy (DRE). We included patients with completed evaluations and data on duration from initiation of presurgical evaluation to final surgical decision. We compared patient characteristics and evaluation components between those with long duration evaluations (> 75% quartile) and those with short evaluations (< 25% quartile). Akaike information criteria selection identified variables associated with longer duration. From these, we developed a logistic prediction model for evaluation duration, using a random 80/20 training/testing split of the entire cohort. The model was tested among institutions with ≥ 10 patients in the cohort to assess its accuracy in predicting long durations. Linear models for each site assessed each variable's impact on duration. Variables with < 10% of the patient population at each site were excluded. Beta values were compared to identify intra‐ and inter‐institution variability and to delineate institutions with the shortest added duration for each variable. Results Of 2318 patients undergoing surgical evaluation, 1655 (71%) from 23 sites had complete data. Median evaluation duration was 8 weeks (interquartile range 3–22); 453 (27%) were short‐duration evaluations and 414 (25%) were long‐duration evaluations. Multiple patient and evaluation characteristics were associated with duration (Table 1). Table 6 provides the average duration each variable contributes to evaluation by site, highlighting the shortest durations compared with other groups. Conclusions Duration of presurgical evaluation for DRE can be accurately modeled using multiple patient characteristics and testing strategies commonly employed in epilepsy surgery evaluations. This predictive model can not only estimate evaluation duration but also identify opportunities to improve systemic efficiency. Institution‐level modeling identifies specific program strengths, providing an opportunity to learn from successful processes. Subsequent research will focus on institutional process mapping to better understand systemic practices that lead to improved efficiencies, then sharing these processes across the consortium to shorten evaluation durations.

Objective Epilepsy surgery is vital in managing of children with drug-resistant epilepsy. Noninvasive and invasive testing modalities allow for evaluation and treatment of children with drug-resistant epilepsy. Evidence-based algorithms for this process do not exist. This study examines expert response to a vignette of pediatric nonlesional epilepsy to assess associations in evaluation and treatment choices. Methods We analyzed annual report data and an epilepsy practice survey reported in 2020 from 135 pediatric epilepsy center directors in the United States. Characteristics of centers along with noninvasive and invasive testing and surgical treatment strategies were collected. Multivariable logistic regression modeling was performed. Results The response rate was 100% with 135 responses included in the analyses. Most used noninvasive testing modalities included Neuropsychology evaluation (90%), interictal brain fluorodeoxyglucose-positron emission tomography (85%), and functional magnetic resonance imaging (MRI) (72%) with nearly half obtaining genetic testing. Choosing functional MRI was associated with stereo electroencephalography (EEG) ( P = .025) and selecting Wada with subdural grid/strips ( P = .038). Directors from pediatric-only centers were more likely to choose stereo EEG as opposed to combined centers ( P = .042). Laser interstitial thermal therapy was almost 7 times as likely to be chosen as a treatment modality compared with open resection in dedicated pediatric centers (OR 6.96, P = .002). Significance In a vignette of nonlesional childhood drug-resistant epilepsy, epilepsy center directors’ patterns of noninvasive testing, invasive testing, and treatment were examined. Management choices were associated with pediatric versus combined pediatric/adult center characteristics. Expert opinions demonstrated equipoise in evaluation and management of children with drug-resistant epilepsy and the need for evidence-based management strategies.

AbstractObjectivesThe main goal of presurgical evaluation in drug‐resistant focal epilepsy is to identify a seizure onset zone (SOZ). Of the noninvasive, yet resource‐intensive tests available, ictal single‐photon emission computed tomography (SPECT) aids SOZ localization by measuring focal increases in blood flow within the SOZ via intravenous peri‐ictal radionuclide administration. Recent studies indicate that geographic and center‐specific factors impact utilization of these diagnostic procedures. Our study analyzed successful ictal SPECT acquisition (defined as peri‐ictal injection during inpatient admission) using surgery‐related data from the Pediatric Epilepsy Research Consortium (PERC) surgery database. We hypothesized that a high seizure burden, longer duration of video EEG monitoring (VEEG), and more center‐specific hours of SPECT availability would increase the likelihood of successful ictal SPECT.MethodsWe identified study participants (≤18 years of age) who underwent SPECT as part of their phase 1 VEEG from January 2018 to June 2022. We assessed association between ictal SPECT outcomes (success vs. failure) and variables including patient demographics, epilepsy history, and center‐specific SPECT practices.ResultsPhase 1 VEEG monitoring with ictal SPECT injection was planned in 297 participants and successful in 255 participants (85.86%). On multivariable analysis, the likelihood of a successful SPECT injection was higher in patients of non‐Hispanic ethnicity (p = 0.040), shorter duration VEEG (p = 0.004), and higher hours of available SPECT services (p < 0.001). Higher seizure frequency (p = 0.033) was significant only in bivariate analysis. Patients treated at centers with more operational hours were more likely to experience pre‐admission protocols prior to VEEG (p = 0.002).SignificanceThere is inter‐center variability in protocols and SPECT acquisition capabilities. Shorter duration of EEG monitoring, non‐Hispanic ethnicity (when on private insurance), extended operational hours of nuclear medicine as noted on multivariate analysis and higher seizure frequency in bivariate analysis are strongly associated with successful ictal SPECT injection.Plain Language SummaryIn pediatric patients with drug‐resistant epilepsy, single‐photon emission computed tomography (SPECT) scans can be helpful in localizing seizure onset zone. However, due to many logistical challenges described below, which include not only the half‐life of the technetium isotope used to inject intravenously during a seizure (called the ictal SPECT scan) but also available nuclear scanner time in addition to the unpredictability of seizures, obtaining an ictal SPECT during a planned elective inpatient hospital stay is not guaranteed. Thus, as healthcare costs increase, planning a prolonged hospital stay during which an ictal SPECT scan is not feasible is not optimal. We leveraged our prospective surgery database to look at center‐specific factors and patient‐specific factors associated with an ictal SPECT injection in the first, pediatric‐focussed, large‐scale, multicenter, prospective, SPECT feasibility study. We found that longer availability of the scanner is the most important center‐specific factor in assuring ictal SPECT injection. Although seizure frequency is an important patient‐specific factor on bivariate analysis, this factor lost statistical significance when other factors like patient insurance status and video EEG duration were also considered in our multivariable logistical model.

AbstractObjectivesCorpus callosotomy (CC) is used to reduce seizures, primarily in patients with generalized drug‐resistant epilepsy (DRE). The invasive nature of the procedure contributes to underutilization despite its potential superiority to other palliative procedures. The goal of this study was to use a multi‐institutional epilepsy surgery database to characterize the use of CC across participating centers.MethodsData were acquired from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database, a prospective observational study collecting data on children 0–18 years referred for surgical evaluation of DRE across 22 U.S. pediatric epilepsy centers. Patient, epilepsy, and surgical characteristics were collected across multiple CC modalities. Outcomes and complications were recorded and analyzed statistically.ResultsEighty‐three patients undergoing 85 CC procedures at 14 participating epilepsy centers met inclusion criteria. Mean age at seizure onset was 2.3 years (0–9.4); mean age for Phase I evaluation and surgical intervention were 9.45 (.1–20) and 10.46 (.2–20.6) years, respectively. Generalized seizure types were the most common (59%). Complete CC was performed in 88%. The majority of CC procedures (57%) were via open craniotomy, followed by laser interstitial thermal therapy (LiTT) (20%) and mini‐craniotomy/endoscopic (mc/e) (22%). Mean operative times were significantly longer for LiTT, whereas mean estimated blood loss was greater in open cases. Complications occurred in 11 cases (13%) and differed significantly between surgical techniques (p < .001). There was no statistically significant difference in length of postoperative stay across approaches. Mean follow‐up was 12.8 months (range 1–39). Favorable Engel outcomes were experienced by 37 (78.7%) of the patients who underwent craniotomy, 10 (58.8%) with LiTT, and 12 (63.2%) with mc/e; these differences were not statistically significant.SignificanceCC is an effective surgical modality for children with DRE. Regardless of surgical modality, complication rates are acceptable and seizure outcomes generally favorable. Newer, less‐invasive, surgical approaches may lead to increased adoption of this efficacious therapeutic option for pediatric DRE.