# Research progress on the electrophysiological indicators to predict the efficacy of vagus nerve stimulation for drug-refractory epilepsy

## TL;DR

This review discusses potential electrophysiological indicators to predict the effectiveness of Vagus Nerve Stimulation for drug-resistant epilepsy.

## Contribution

The paper updates potential biomarkers for VNS outcomes in drug-resistant epilepsy patients.

## Key findings

- EEG activity and event-related potentials are potential biomarkers for VNS outcomes.
- Heart rate variability and laryngeal muscle evoked potentials may also predict VNS effectiveness.
- The mechanism of VNS action remains unknown, complicating the identification of optimal indicators.

## Abstract

Vagus nerve stimulation (VNS) is an important treatment option for drug-refractory epilepsy (DRE), with well-established efficacy and safety in clinical practice for more than 20 years. However, it is very difficult to find the optimal electrophysiological indicators for the effectiveness of VNS on DRE because the mechanism of action is unknown. In this review, we provide an update of the potential applications of VNS outcomes in patients with drug-resistant epilepsy. Electroencephalographic (EEG) activity, event-related potentials, EEG synchronization levels, magnetoencephalographic, laryngeal muscle evoked potentials, and heart rate variability are potential biomarkers for VNS outcomes in people with DRE.