Abstracts

Comparison of Standard and Closed-Loop Vagus Nerve Stimulation for Treatment of Pediatric Drug-Resistant Epilepsy: A Propensity-Matched Retrospective Cohort Study

Abstract number : 1.322
Submission category : 9. Surgery / 9B. Pediatrics
Year : 2021
Submission ID : 1826601
Source : www.aesnet.org
Presentation date : 12/4/2021 12:00:00 PM
Published date : Nov 22, 2021, 06:54 AM

Authors :
Nallammai Muthiah, BS - University of Pittsburgh Medical Center; Emefa Akwayena - University of Pittsburgh Medical Center; Nikhil Sharma - University of Pittsburgh Medical Center; Lena Vodovotz - University of Pittsburgh Medical Center; Jong Jeong - University of Pittsburgh Graduate School of Public Health; Gretchen White - University of Pittsburgh; Taylor Abel - University of Pittsburgh Medical Center

Rationale: For epilepsy patients with drug-resistant, unresectable epilepsy, vagus nerve stimulation (VNS) is an option for seizure control. Approximately 60% of patients will achieve ≥50% seizure reduction with VNS. Closed-loop VNS models detect ictal tachycardia and responsively stimulate the vagus nerve. The effectiveness of closed-loop models compared to traditional models for pediatric epilepsy is unknown.

Methods: A retrospective electronic medical record review at UPMC Children’s Hospital of Pittsburgh between January 1st 2009 and January 1st 2020 was performed. Patients with drug-resistant epilepsy who underwent VNS implantation were included. Patients were divided into groups based on VNS model: traditional VNS and closed-loop VNS. Patients who transitioned from traditional to closed-loop models were excluded from this analysis. The primary outcome was seizure frequency reduction. Chi-squared tests and independent sample t-tests were performed to compare groups. Propensity scores were calculated to match patients and assess seizure frequency reduction at several follow-up time points.

Results: The percentage of traditional VNS patients (n=308) achieving >50% seizure reduction at one, two, and four years was 42.6%, 47.6%, and 51.1%, respectively, whereas it was 40.5%, 63.0%, and 53.8% in the closed-loop group (n=62), respectively. There was no difference in total seizure frequency reduction between the traditional and closed-loop groups after years 1 (p=0.799). 2 (p=0.138), or 4 (p=849), even after propensity score matching. For patients with focal seizures preoperatively as well as among those with generalized seizures preoperatively, there were still no differences in seizure frequency reduction between groups at years 1 (pfocal=0.791; pgeneralized=0.926), 2 (pfocal=0.416; pgeneralized=0.058), 4 (pfocal=0.699; pgeneralized=0.669), or latest follow-up (pfocal=0.378; pgeneralized=0.516). The mean change in AEDs from pre- to post-VNS was 0.03 + 1.421 AEDs for the traditional VNS group and 0.06 + 0.827 for the closed-loop group, with no significant difference between groups (p=0.809).

Conclusions: Among pediatric patients with drug-resistant, unresectable epilepsy, closed-loop VNS does not allow more patients to achieve ≥50% seizure frequency reduction compared to traditional models. When further analyzing response to VNS by origin of seizure activity, closed-loop VNS performs similarly to traditional VNS for focal and generalized epilepsy. Closed-loop VNS does not allow for reduction in AED quantity compared to traditional VNS.

Funding: Please list any funding that was received in support of this abstract.: None.

Surgery