Wong-Kisiel, Lily C.

Abstract Introduction Quantitative interpretation of pediatric brain [ 18 F]-FDG PET is limited by the lack of age-matched normative reference databases, despite substantial developmental variation in cerebral glucose metabolism. This study aimed to construct a large-scale normative pediatric [ 18 F]-FDG PET database and develop an age-specific z-score mapping framework for quantitative evaluation of pediatric epilepsy. Method Pediatric brain PET data were retrospectively derived from clinically acquired whole-body or dedicated [ 18 F]-FDG PET examinations in participants 0–19 years of age without neurologic disease or visible brain abnormalities. A total of 417 PET scans from 341 participants were stratified into five developmental age groups: infancy, early childhood, middle childhood/school age, adolescence, and late adolescence. SUVR maps were generated using whole-brain atlas and brainstem reference regions. Voxel-wise t-test analyses were performed to characterize age- and sex-related metabolic differences. Age-specific voxel-wise mean and standard deviation maps were generated from the normative cohort and used to calculate age-matched hypometabolic z-score maps in 14 pediatric patients with epilepsy. The resulting abnormalities were qualitatively evaluated for concordance with epileptogenic findings identified on clinical MRI and/or PET by expert image review. Results Voxel-wise analyses demonstrated prominent age-dependent SUVR differences, particularly between infancy and older age groups. With whole-brain atlas normalization, older children showed progressively higher relative SUVR in cortical and cerebellar gray matter regions, whereas infancy showed relatively higher SUVR in the occipital cortex, white matter, thalamus, and brainstem. Brainstem normalization produced distinct developmental patterns, emphasizing higher white matter SUVR in infancy and broader gray matter differences in older groups. Sex-related differences were limited and regionally specific. Whole-brain atlas normalization showed lower variability than brainstem normalization and was selected for z-score mapping. In representative epilepsy cases, age-matched z-score maps identified focal or regional hypometabolism corresponding to malformations of cortical development, focal cortical dysplasia, mesial temporal sclerosis, nonlesional MRI cases, remote insult, tumor-related abnormalities, and Sturge-Weber syndrome. Discussion A large-scale normative pediatric [18F]-FDG PET database can support developmentally appropriate quantitative interpretation of pediatric brain PET. Age-matched z-score mapping may complement visual assessment by highlighting abnormal cerebral glucose metabolism in pediatric epilepsy, although findings should be interpreted with MRI, EEG, seizure semiology, and other presurgical data.

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.

Objective Lennox–Gastaut syndrome (LGS) is a severe treatment‐resistant epilepsy. Although vagus nerve stimulation (VNS) and deep brain stimulation (DBS) are established therapies, comparative data and the impact of dual neuromodulation remain limited. We compared seizure outcomes across VNS, DBS, and combined DBS + VNS therapy in LGS. Methods This retrospective cohort study at Mayo Clinic (2005–2024) included LGS patients treated with VNS and/or DBS . Seizure frequency was assessed at 6, 12, and 24 months post‐stimulation. Responder was defined as 50% or more seizure reduction. Results Forty patients were included (42% female, median, 150 seizures/month). Eleven patients underwent sequential VNS followed by DBS and contributed data to 2 treatment epochs, yielding 3 treatment groups: VNS alone (n = 29), DBS alone (n = 12), and DBS + VNS (n = 10). At 24 months, median seizure reduction rate was comparable between VNS (50%; 95% confidence interval [ CI], 44–75%) and the overall DBS cohort (59%, 95% CI, 33–86%) ( p = 0.54). However, a significant difference emerged when comparing the 3 treatment arms ( p = 0.027). Specifically, DBS + VNS therapy yielded significantly greater median reduction rate (81%, 95% CI, 60–99%) than DBS alone (43%, 95% CI, 0–58%) ( p adj = 0.027) or VNS alone (50%, 95% CI, 44.4–75.0%) ( p adj = 0.048). Four patients attained sustained seizure freedom above 1 year at last follow‐up. Interpretation VNS and DBS provide comparable seizure reduction in LGS over a 2‐year follow‐up period. DBS + VNS was associated with further improvements in seizure reduction in this small, retrospective dataset. This possibility warrants further investigation. ANN NEUROL 2026

Abstract In epilepsy patients lacking magnetic resonance imaging‐visible lesions such as focal cortical dysplasia (FCD), surgical resections target regions with abnormal electroencephalographic (EEG) activity. However, histopathological identification of subtle cortical architectural abnormalities in these specimens remains challenging. We investigated whether artificial intelligence (AI)‐based morphometric and spatial analysis of NeuN‐stained cortical sections could detect neuronal architectural disorganization in epilepsy resections, including regions without definitive histologic dysplasia. Whole slide images were generated from 83 FCD regions and 19 neurologically normal autopsy controls. Regions of interest were annotated in QuPath as FCD, FCD‐adjacent, FCD‐distant, apparently normal (abnormal EEG without histologic dysplasia), and true normal (autopsy controls). NeuN‐positive neurons were detected using QuPath (90% sensitivity, 12% false positive rate). Spatial and morphometric features—including neuronal clustering, distribution inhomogeneity, and nuclear morphology—were extracted and used to train a multinomial, Least Absolute Shrinkage and Selection Operator‐regularized regression classifier. The classifier achieved 70.6% accuracy in subregion classification and 88.2% accuracy in overall specimen diagnosis. Notably, regions with abnormal EEG but lacking histologic dysplasia exhibited quantifiable architectural disorganization similar to those seen in areas adjacent to FCD and distinct from control tissue. AI‐driven analysis of neuronal morphology and spatial distribution reveals subtle cortical disorganization in epilepsy resections, including in histologically ambiguous regions. Further investigation is warranted to determine if this methodology can enhance the diagnostic yield of neuropathological evaluation and support more precise surgical targeting in epilepsy.

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.