Karakas, Cemal

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 Objective The objective of this study is to characterize contemporary surgical management practices and factors influencing surgical decision‐making in the management of Lennox–Gastaut Syndrome (LGS) across pediatric epilepsy centers in the United States. Methods A 45‐item cross‐sectional survey was developed and distributed to Pediatric Epilepsy Research Consortium centers. Domains included institutional demographics, surgical evaluation timing and goals, presurgical workup, procedural utilization and outcomes, and barriers to surgery. Descriptive statistics and thematic analysis were performed. Results Thirty‐two pediatric epilepsy centers participated (38% response), the majority comprising pediatric epileptologists at Level 4 National Association of Epilepsy Centers. Most centers (66%) considered surgery after failure of 3–4 antiseizure medications. Presurgical workup typically included brain magnetic resonance imaging (MRI), long‐term electroencephalography (EEG) monitoring, and neuropsychological assessment, while use of functional imaging, magnetoencephalography, and intracranial EEG varied considerably. All centers offered vagus nerve stimulation and corpus callosotomy; 80%–90% offered resection, hemispherectomy, responsive neurostimulation (RNS); 60%–65% offered deep brain stimulation (DBS) and laser ablation. Among centers offering RNS, half targeted thalamic structures exclusively, and the remainder targeted cortical or combined cortical‐thalamic structures; the centromedian nucleus was the preferred thalamic target for RNS and DBS. Surgical decision‐making was influenced by patient characteristics, procedural considerations, and systemic factors. Seizure frequency, family preference, and multidisciplinary input were highly rated across all interventions. Etiology was critical for resection and hemispherectomy, while financial constraints, insurance barriers, and the need for future neuroimaging impacted neuromodulation selection. Scenario‐specific trends included less frequent consideration of DBS and RNS in children under five years, less use of hemispherectomy in older children, preference for corpus callosotomy in children with predominantly drop seizures, and procedural selection based on MRI findings. Significance Substantial variability exists in the surgical management of LGS. These findings highlight critical opportunities to harmonize practices, reduce disparities, and guide comparative effectiveness research to optimize outcomes. Plain Language Summary Lennox–Gastaut Syndrome (LGS) is a severe form of epilepsy that may require surgery when medications are not effective. This study found that surgical care for LGS varies widely across pediatric epilepsy centers in the United States, including when surgery is recommended, how patients are evaluated, and which procedures are available. Newer approaches such as brain stimulation are being used more often, although access remains inconsistent. These findings highlight the need for clearer treatment pathways to ensure that children with LGS have equitable access to the best possible care.

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.