Optimization of the Parameters of Vagal Nerve Stimulation

Study Overview
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Brief Summary
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Vagal nerve stimulation (VNS) is one of the neuromodulation techniques that can be indicated in patients suffering from refractory epilepsies, especially when an open resection has failed or is not indicated. However to date it is not possible to predict which patients will respond and what are the best parameters of stimulation to be set (pulse width, frequency and intensity). It has been shown that responders to VNS have reduced interictal cortical synchronicity on scalp EEG based on phase lag index (PLI), a marker of functional connectivity (Fc) The aim of this study is to test the following hypothesis: setting the parameters of stimulation on the basis of the lowest values of Phase Lag Index (PLI) obtained on scalp EEG with different settings of parameters (as compared with a randomly chosen set of commonly used parameters) will increase the rate of responders to VNS.

Official Title
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Optimization of the Parameters of Vagal Nerve Stimulation in Pharmaco- Resistant Epileptic Patients Based on a Surface EEG Index of Functional Connectivity (PLI: Phase Lag Index): a Randomized Double-blind Multicenter Controlled Study.

Conditions
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Epilepsy

Intervention / Treatment
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* Other: Choice of VNS set of parameters based on the lowest PLI
* Other: EEG


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female epileptic patients over 12 years of age Suffering from pharmaco-resistant epilepsy With newly implanted VNS Aspire SR device Surgery performed in the previous 6 months Electrode impedance should be within normal range ( < 4000 Ohms) Auto-stim mode working properly Mean number of seizures of at least (average 4 (mean value) / months during the baseline period) Patient, parents or legally representatives who have given written informed consent to allow the study data collection and procedures Exclusion Criteria: Difficulty to read or understand the French language, or inability to understand the information regarding the study Total patient's IQ below 64 Subject in exclusion period due to enrolment in another study Patient with postoperative left vocal cord paralysis Patient on VNS since more than 6 months

Ages Eligible for Study
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Minimum Age: 12 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Control<br>VNS therapy with randomly-set combination of parameters (similar to current practice) | Other: EEG<br>* Patient will have an EEG and 12 sets of parameters will be tested. EEG results will be analyzed which will allow to determine the set involving the lowest phase lag index.<br>|
| Experimental: Experimental<br>VNS therapy with set combination of parameters chosen based on the lowest phase lag index | Other: Choice of VNS set of parameters based on the lowest PLI<br>* Vagal nerve stimulation according to PLI results.<br>Other: EEG<br>* Patient will have an EEG and 12 sets of parameters will be tested. EEG results will be analyzed which will allow to determine the set involving the lowest phase lag index.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean number of seizures per month |  | Change from baseline to 6 months | 
| Mean number of seizures per month |  | Change from baseline to 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of responders in each group |  | Change from baseline to 6 months | 
| Number of responders in each group |  | Change from baseline to 12 months | 
| Number of generalized seizures |  | Change from baseline to 6 months | 
| Number of generalized seizures |  | Change from baseline to 12 months | 
| Number of seizures with falls |  | Change from baseline to 6 months | 
| Number of seizures with falls |  | Change from baseline to 12 months | 
| Number of seizures with alteration of consciousness |  | Change from baseline to 6 months | 
| Number of seizures with alteration of consciousness |  | Change from baseline to 12 months | 
| Score of depression | NDDI-E | Change from baseline to 6 months | 
| Score of depression | NDDI-E | Change from baseline to 12 months | 
| Score of anxiety | GAD-7 | Change from baseline to 6 months | 
| Score of anxiety | GAD-7 | Change from baseline to 12 months | 
| Score of quality of life | QUOLIE 31 | Change from baseline to 6 months | 
| Score of quality of life | QUOLIE 31 | Change from baseline to 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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epilepsy, vagal nerve stimulation, phase lag index