Abstracts

This is a Late-Breaking abstract.

Rationale: Vagus nerve stimulation (VNS) therapy has been a widely adopted therapy for drug-resistant epilepsy (DRE) for several decades.  However, the paucity of evidence-based recommendations for VNS dosing and titration has led to variability in practical implementation of VNS around the globe.  _x000D_  
Methods: A survey was developed to assess VNS dosing and titration behaviors amongst healthcare professionals (HCPs) treating patients with DRE. All HCPs treating patients with DRE were eligible to take part in this survey, not just those that manage neuromodulation therapies or VNS Therapy. The survey was executed at the 2022 European Epilepsy Congress in Geneva Switzerland and via email by VNS researchers from the UC Louvain.

Results: As of August 2022, 79 responses have been collected from largely Western European HCPs (68/79; 86.1%).  Most respondents reported using at least one neuromodulation modality for treatment of DRE in their clinical practice (68/79; 86.1%), with the majority using VNS only (42/68; 61.8%). Further investigation of practice behavior was possible in the 57 respondents that reported personal responsibility for management of VNS in their practice (83.3% of the 68 VNS users). Of these VNS programmers, the average minimum target output current was 1.40 mA and the maximum target was 2.43 mA; however, there was significant variability in responses and some users reported programming VNS output currents to a maximum of 0.5 mA. The most common pulse width and frequency used were 250 µsec (37/57; 64.9%) and 20 Hz (29/57; 50.9%), respectively. On average, HCPs reached what they perceived as the target dose within 10.5 weeks (range, 2 to 56 weeks). Respondents report assessing the impact of VNS at 6 months after achieving the perceived target dose range. Some users had access to VNS devices with novel features including cardiac-based seizure detection (AutoStim) and Scheduled Programming. The majority of VNS users with access to these features reported using them in most patients, with 77.2% reporting using AutoStim in more than half of their patients, and 53.3% reported using Scheduled Programming in as many patients as possible. When assessing dosing and titration practices of experienced users (>100 patients treated) vs less experienced users (< 20 patients treated) a possible trend towards higher maximal VNS output current was found in the experienced user group but did not reach significance (average 2.69 mA vs. 2.15 mA). Increasing the number of responses to this survey will be crucial in investigating whether experience with VNS significantly impacts dosing and titration.

Conclusions: While typical VNS management in Western European countries mostly follows the manufacturer’s recommendations for use, individual VNS users may have highly variable dosing and titration approaches.

Funding: Livanova