Vagus nerve stimulation-induced laryngeal motor evoked potentials for response prediction and intensity titration in drug-resistant epilepsy

Alexandre Berger; Evelina Carapancea; Simone Vespa; Venethia Danthine; Pascal Doguet; Jean Delbeke; Antoine Nonclercq; Riëm El Tahry

doi:10.1016/j.clinph.2023.01.009

Vagus nerve stimulation-induced laryngeal motor evoked potentials for response prediction and intensity titration in drug-resistant epilepsy

Clin Neurophysiol. 2023 Mar:147:99-107. doi: 10.1016/j.clinph.2023.01.009. Epub 2023 Jan 27.

Authors

Alexandre Berger¹, Evelina Carapancea², Simone Vespa², Venethia Danthine², Pascal Doguet³, Jean Delbeke⁴, Antoine Nonclercq⁵, Riëm El Tahry⁶

Affiliations

¹ Institute of Neuroscience (IoNS), Department of Clinical Neuroscience, Université Catholique de Louvain, Brussels, Belgium; Synergia Medical SA, Mont-Saint-Guibert, Belgium; Sleep and Chronobiology Lab, GIGA-Institute, CRC-In Vivo Imaging Unit, University of Liège, Liège, Belgium. Electronic address: alexandre.berger@uclouvain.be.
² Institute of Neuroscience (IoNS), Department of Clinical Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
³ Synergia Medical SA, Mont-Saint-Guibert, Belgium.
⁴ Institute of Neuroscience (IoNS), Department of Clinical Neuroscience, Université Catholique de Louvain, Brussels, Belgium; Institute of Neuroscience, LCEN3, Department of Neurology, Ghent University, Ghent, Belgium.
⁵ Institute of Neuroscience (IoNS), Department of Clinical Neuroscience, Université Catholique de Louvain, Brussels, Belgium; Bio, Electro and Mechanical Systems Department (BEAMS), Ecole Polytechnique de Bruxelles, Brussels, Belgium.
⁶ Institute of Neuroscience (IoNS), Department of Clinical Neuroscience, Université Catholique de Louvain, Brussels, Belgium; Center for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium; Walloon Excellence in Life Sciences and Biotechnology (WELBIO) Department, WEL Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium.

PMID: 36764043
DOI: 10.1016/j.clinph.2023.01.009

Abstract

Objective: The objective of the study was to record Laryngeal Motor Evoked Potentials (LMEPs) in Vagus Nerve Stimulation (VNS)-implanted patients suffering from Drug-Resistant Epilepsy (DRE). Based on these recordings, LMEPs characteristics were evaluated and compared between responders (R) and non-responders (NR). Finally, possible under- or over-stimulation was assessed based on a physiological indicator of fiber engagement.

Methods: Mean dose-response curves were compared between R and NR. A Support Vector Machine (SVM) model was built based on both LMEP and dose-response curves features, to discriminate R from NR. For the exploration of possible under- or over-stimulation, a ratio between the clinically applied stimulation intensity and the intensity yielding to LMEP saturation was computed for each patient.

Results: A trend towards a greater excitability of the nerve was observed in R compared to NR. The SVM classifier discriminated R and NR with an accuracy of 80%. An ineffective attempt to overstimulate at current levels above what is usually necessary to obtain clinical benefits was suggested in NR.

Conclusions: The SVM model built emphasizes a possible link between vagus nerve recruitment characteristics and treatment effectiveness. Most of the clinically responding patients receive VNS at a stimulation intensity 1-fold and 2-fold the intensity inducing LMEP saturation.

Significance: LMEP saturation could be a practical help in guiding the titration of the stimulation parameters using a physiological indicator of fiber engagement.

Keywords: Biomarker; Epilepsy; Larynx; Motor-evoked potentials; SVM; Vagus nerve stimulation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Drug Resistant Epilepsy* / etiology
Evoked Potentials, Motor
Humans
Larynx*
Treatment Outcome
Vagus Nerve / physiology
Vagus Nerve Stimulation*