2023 American Academy of Neurology Abstract Website

Cornelia Drees¹, Mesha-Gay Brown², Danielle McDermott³, Lesley Kaye⁴, O'Dwyer Rebecca⁵, Micheal Macken⁶, Muhammad Zafar⁷, William Tatum⁸, Zeenat Jaisani⁹, Kristl Vonck¹⁰, Pegah Afra¹¹, Blake Newman¹², Ryan Verner¹³, Amy Keith¹³, Mei Jiang¹³, Selim Benbadis¹⁴
¹Mayo Clinic Arizona, ²Neurology, Centura Health, ³University of Colorado, ⁴Department of Neurology, CU Anschutz Medical Campus, ⁵Rush University, ⁶Northwestern University, ⁷Duke University, ⁸Mayo Clinic, ⁹University of Alabama Birmingham, ¹⁰Ghent University Hospital, ¹¹Weill-Cornell Medicine, Department of Neurology, ¹²University of Utah, ¹³LivaNova Company, ¹⁴University of South Florida

Objective:

We assessed the clinical impact of Microburst-VNS in an early feasibility study.

Background:

Vagus nerve stimulation (VNS) therapy is an established treatment for drug-resistant epilepsy. New settings called “microburst stimulation” (µVNS) with high-frequency bursts are hypothesized to be more tolerable and efficacious than standard VNS (VNS) therapy.

Design/Methods:

This prospective, unblinded multicenter study aimed to recruit 2 cohorts of 20 VNS-naïve patients each, age ≥12 years, with either refractory focal (FE) or generalized epilepsy with tonic-clonic convulsions (GE). Enrolled subjects underwent 4 functional MRIs to titrate settings to µVNS parameters with the most robust thalamic blood-oxygen-level-dependent signal response. Data collected at baseline and during 12-months follow-up included demographics, seizure frequency, antiseizure medications (ASMs), quality of life in epilepsy questionnaires (QOLIE-31-P/QOLIE-AD-48), seizure severity questionnaire (SSQ), VNS parameters/malfunction and adverse events (AE). Primary endpoints were safety and efficacy, secondary endpoints changes in QOLIE and SSQ scores.

Results:

A total of 32 subjects were implanted with µVNS, 20 FE and 12 GE patients. At baseline, patients had failed 4-6 ASMs (FE 4.5 vs GE 6.6). For the total population, responder rates (≥50% seizure reduction) at 6- and 12-months were 41.9% and 63.3%, respectively, with 63.2% of responders experiencing ≥80% reduction (12/19). At 12-months, overall seizure severity decreased in 70% of subjects (21/30), QOLIE total scores improved, and median ASM drug load decreased by 10%. Stimulation/device-related AE from 6 to 12 months were reported in one FE patient (cough, battery replacement), and 5 GE patients (dysphonia, device removal, implant site pain, seizure, agitation).

Conclusions:

Despite limitations of design, sampling, and premature termination, µVNS therapy seems safe and potentially more efficacious than VNS, as responders appeared more likely to have ≥80% seizure reduction within the first 12 months. Seizure severity, QOL, and ASM load improved. Rate of AEs were similar to VNS. Further prospective study is warranted.