Overview
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.
Eligibility
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