Laryngeal Motor Evoked-potentials as a Biomarker of Vagus Nerve Stimulation in Epileptic Patients

Study Overview
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Brief Summary
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The goal of this study is to record and characterize larynx evoked motor potentials induced by vagus nerve stimulation. This study will include 10 adult patients implanted with a Vagus nerve stimulator, followed at the Center for Refractory Epilepsy at Cliniques St Luc. The inclusion criteria are: (1) patient aged between 18 and 65 years ; (2) cervical VNS device (Cyberonics, Houston, TX, USA) implanted for at least 6 months, (3) normal electrode impedance of the electrode. Exclusion criteria are (1) presence of a concomitant laryngeal pathology or recurrent laryngeal nerve damage, independent from VNS ; (2) important VNS side effects reported by the patient, such as severe dyspnea (grade III-IV) or severe pain in the neck/ear region.

Official Title
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NEURO-LARYNX:Laryngeal Motor Evoked-potentials as a Biomarker of Vagus Nerve Stimulation

Conditions
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Epilepsy

Intervention / Treatment
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* Other: Characterization of Vagus nerve stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients aged between 18 and 65 years Vagus nerve stimulation implanted for at least 6 months No impedance issues with the VNS electrode Exclusion Criteria: presence of a concomitant laryngeal pathology or RLN damage, independent from vagus nerve stimulation important side effects of the VNS reported by the patient such as dyspnea, pain in neck/ear region and gastrointestinal complaints.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Interventional Model Description: Patients participating will be asked to come to the Neurophysiology Department of Saint Luc Clinic to peform the laryngeal evoked motor potential.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: refractory epilepsy patients<br>All patients belong to the refractory epilepsy group. Intervention: Characterization of Vagus nerve stimulation: Evoked potentials (EP) are recorded using an EEG/EP digital acquisition system | Other: Characterization of Vagus nerve stimulation<br>* Characterization of Vagus nerve stimulation induced larynx evoked motor potential. Patients participating in the study will be asked to come to perform the experiment (duration maximum 1 hour) at the Neurophysiology Department of Saint Luc .<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Laryngeal motor evoked potential (LMEP) | Characteristics of the laryngeal motor evoked potential Threshold : the mA of current output necessary for evoking the LMEP Latency : the time between the negative peak of the stimulation artifact and the first positive deflection of the LMEP Amplitude : the difference in μV between the lowest negative and the highest positive peak of the LMEP Duration : the time between the first positive deflection of LMEP and the return to the noise level Dose- response curve: the relation between increasing intensity of vagal nerve stimulation and amplitude of the LMEP | the LMEP is recorded for 60 minutes from the moment the patient arrives to the clinic to perform the test | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Epilepsy