Search

Objective: Epilepsy affects approximately 470,000 children in the United States. The estimated median incidence is 50.4 cases per 100,000 persons per year. There are approximately 3.1 million seizure-related emergency department (ED) visits per year among children. Vagus nerve stimulation (VNS) is a treatment option for drug-resistant epilepsy (DRE). While its primary goal is to decrease seizure burden, VNS may decrease seizure intensity and improve quality of life. The authors assessed whether VNS decreased the number of seizure-related ED visits in a cohort of children with DRE., Methods: The authors performed a retrospective chart review of pediatric patients (aged 0-21 years) who underwent implantation of a vagus nerve stimulator between January 2009 and January 2020 at the University of Pittsburgh Medical Center Children's Hospital of Pittsburgh. They used paired t-tests to assess differences in the number of ED visits 2 years before versus 2 years after VNS device implantation. Univariable linear regression analyses were used to test associations of preoperative characteristics with change in the number of ED visits following vagus nerve stimulator insertion., Results: This study included 240 patients. Compared with patients without seizure-related ED visits before VNS, patients with ≥ 1 ED visits were younger in age at first VNS surgery (9.5 vs 10.8 years), had a shorter epilepsy duration before VNS surgery (5.8 vs 7.4 years), had a later year of device implantation (2014 vs 2012), and on average took more antiseizure medications (ASMs; 2.4 vs 2.1). There was no significant difference between the total number of seizure-related ED visits pre- versus post-VNS surgery (1.72 vs 1.59, p = 0.50), and no difference in status epilepticus-related visits (0.59 vs 0.46, p = 0.17). Univariable linear regression analyses revealed a mean change in ED visits of +0.3 for each year prior to 2022 and -0.5 for each additional ASM that patients took before vagus nerve stimulator insertion., Conclusions: This single-institution analysis demonstrated no significant change in the number of seizure-related ED visits within 2 years following VNS device implantation. Earlier VNS surgery was associated with more seizure-related ED visits after device insertion, suggesting that medical management and center experience may play a role in decreasing seizure-related ED visits. A greater number of ASMs was associated with fewer seizure-related ED visits after VNS device insertion, suggesting the role of medical management, patient baseline seizure threshold, and caregiver comfort with at-home seizure management.

Purpose: Epilepsy following non-accidental trauma (NAT) occurs in 18% of pediatric patients. About 33% of patients with epilepsy develop drug-resistant epilepsy. For these patients, vagus nerve stimulation (VNS) is a palliative treatment option. We aimed to investigate the effectiveness of VNS among pediatric NAT-related epilepsy patients compared to those with non-NAT-related epilepsy., Methods: We performed an 11-year retrospective analysis of VNS implantations for drug-resistant epilepsy at UPMC Children's Hospital of Pittsburgh. Patients were split into two groups: NAT vs. non-NAT. The primary outcome was the attainment of ≥ 50% seizure frequency reduction at 1-year post-VNS implantation. Fisher's exact tests and Wilcoxon rank-sum tests were used to compare groups. Significance was assessed at the alpha = 0.05 level., Results: This analysis included data from 370 pediatric VNS patients, of whom 9 had NAT-related epilepsy. NAT patients had a significantly younger age of epilepsy onset than non-NAT patients (0.3 years vs. 3.3 years). Otherwise, there were no statistically significant baseline differences between groups, including patient sex and quantity of antiseizure medications pre-VNS. Overall, 71% of NAT patients experienced ≥ 50% seizure frequency reduction compared to 48% of non-NAT patients (p = 0.269)., Conclusion: VNS may allow a higher proportion of pediatric patients with NAT-related epilepsy to achieve ≥ 50% seizure frequency reduction compared to other epilepsy etiologies. While the results of this study were not statistically significant, the effect size was large. Our results underscore the need for larger, multi-center studies to validate the effectiveness of VNS for this patient population., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Epilepsy impacts 470,000 children in the United States. For patients with drug-resistant epilepsy (DRE) and unresectable seizure foci, vagus nerve stimulation (VNS) is a treatment option. Predicting response to VNS has been historically challenging. The objective of this study was to create a clinical VNS prediction tool for use in an outpatient setting., Methods: The authors performed an 11-year retrospective cohort analysis with 1-year follow-up. Patients < 21 years of age with DRE who underwent VNS (n = 365) were included. Logistic regressions were performed to assess clinical factors associated with VNS response (≥ 50% seizure frequency reduction after 1 year); 70% and 30% of the sample were used to train and validate the multivariable model, respectively. A prediction score was subsequently developed. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated., Results: Variables associated with VNS response were < 4-year epilepsy duration before VNS (p = 0.008) and focal motor seizures (p = 0.037). The variables included in the clinical prediction score were epilepsy duration before VNS, age at seizure onset, number of pre-VNS antiseizure medications, if VNS was the patient's first therapeutic epilepsy surgery, and predominant seizure semiology. The final AUCs were 0.7013 for the "fitted" sample and 0.6159 for the "validation" sample., Conclusions: The authors developed a clinical model to predict VNS response in a large sample of pediatric patients treated with VNS. Despite the large sample size, clinical variables alone were not able to accurately predict VNS response. This score may be useful after further validation, although its predictive ability underscores the need for more robust biomarkers to predict treatment response.

Objective: Drug-resistant epilepsy occurs in up to 40% of patients with epilepsy who may be considered for epilepsy surgery. For drug-resistant focal epilepsy, up to 50% of patients require invasive monitoring prior to surgery. Of the most common invasive monitoring strategies (subdural electrodes [SDEs] and stereo-electroencephalography [sEEG]), the most cost-effective strategy is unknown despite substantial differences in morbidity profiles., Methods: Using data collected from an internationally representative sample published in available systematic reviews and meta-analyses, this economic evaluation study employs a decision analysis model to simulate the risks and benefits of SDE and sEEG invasive monitoring strategies. In this model, patients faced differing risks of morbidity, mortality, resection, and seizure freedom depending on which invasive monitoring strategy they underwent. A range of cost values was obtained from a recently published single-center cost-utility analysis. The model considers a base case simulation of a characteristic patient with drug-resistant epilepsy using clinical parameters obtained from systematic reviews of invasive monitoring available in the literature. The main outcome measure was the probability of a positive outcome after invasive monitoring, which was defined as improvement in seizures without a complication. Cost-effectiveness was measured using an incremental cost-effectiveness ratio (ICER)., Results: Invasive monitoring with sEEG had an increased cost of $274 and increased probability of effectiveness of 0.02 compared with SDEs, yielding an ICER of $12,630 per positive outcome obtained. Sensitivity analyses varied parameters widely and revealed consistent model results across the range of clinical parameters reported in the literature. One-way sensitivity analyses revealed that invasive monitoring strategy costs were the most influential parameter for model outcome., Conclusions: In this analysis, based on available observational data and estimates of complication costs, invasive monitoring with either SDEs or sEEG was nearly equivalent in terms of cost-effectiveness.

Objective: For epilepsy patients with drug-resistant, unresectable epilepsy, vagus nerve stimulation (VNS) is an option for seizure control. Approximately 40-70% of patients will achieve ≥50% seizure reduction with VNS. New closed loop VNS models detect ictal tachycardia and responsively stimulate the vagus nerve. The effectiveness of closed loop VNS compared to traditional VNS for pediatric epilepsy is unknown., Methods: An 11-year retrospective electronic medical record review at Children's Hospital of Pittsburgh was performed. Patients with drug-resistant epilepsy who underwent VNS implantation were included. Patients were divided into groups based on VNS model: traditional versus closed loop. Those who transitioned from traditional to closed loop VNS were excluded. Given potential for selection bias, propensity scores matching was utilized to compare traditional to closed loop VNS patients. Patients with focal versus generalized epilepsy were also separately analyzed. The primary outcome was "VNS response", defined as at least 50% seizure frequency reduction from baseline., Results: A total of 320 patients were included in this sample. The percentage of matched patients (total n = 220: n = 179 traditional VNS, n = 41 closed loop VNS) who responded to VNS after one year of therapy was 43% for traditional VNS and 39% for closed loop VNS (p = 0.64). After two years of therapy, a higher proportion of closed loop VNS patients than traditional VNS patients responded to VNS among all subgroups, though no differences were statistically significant (p>0.05). Notably, for those with generalized epilepsy, 73% of closed loop patients responded to VNS compared to only 46% of traditional patients (p = 0.10). After two years of VNS therapy, patients were taking approximately the same quantity of antiseizure medications as baseline (change of +0.074 +/- 0.90 ) with no difference between VNS models (p = 0.87)., Significance: Among pediatric patients with drug-resistant epilepsy, closed loop VNS trends towards a higher rate of VNS response after two years of treatment, especially among generalized epilepsy patients. Neither model of VNS allows patients to reduce antiseizure medication quantity after two years., (Copyright © 2021 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)