Refractory EpilepsyVNSNCT07909486
Identification of Biomarkers for Vagus Nerve Stimulation in Patients With Refractory Epilepsy
A study testing Vagus nerve stimulation in people with Refractory Epilepsy, run by Cliniques universitaires Saint-Luc- Université Catholique de Louvain at 1 site in Belgium.
Trial summary
A VNS longitudinal study focused on pre and post-VNS implantation in order to predict the VNS response and to understand better mechanisms of VNS using some connectivity and network measures. Read more about this study
- Who is it for?
- Ages 18 to 79 years
- Conditions the study is for
- Refractory Epilepsy
- What is being tested?
- Vagus nerve stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteBelgium
- Study dates
- 28 Feb 2022to Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 79 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients aged >18 years
- Intelectual Quotient >55 on Wechsler scale (normal or mild cognitive impairment)
- Patients have refractory epilepsy and are planned for VNS implantation
Who cannot join
- Concomitant laryngeal pathology (e.g. recurrent nerve lesions, vocal fold paralysis).
- Dementia/ Neurodegenerative diseases
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Clinique Universitaires Saint-Luc
Brussels, 1200
About this study
A VNS longitudinal study focused on pre and post-VNS implantation in order to predict the VNS response and to understand better mechanisms of VNS using some connectivity and network measures.
- Conditions
- Refractory Epilepsy
- Being tested
- Vagus nerve stimulation
- Medical subject headings
- Drug Resistant Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vagus nerve stimulationDevice
No intervention was performed for the study, since VNS is already part of the treatment of these patients. However, VNS parameters are changed for the sake of the study and reestablished at the end.
| Study group | Role | What they receive |
|---|---|---|
| VNS Implanted Group | Experimental | The investigators will compare responders with non-responders to VNS, but both are part of the implanted arm. Receives: Device: Vagus nerve stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pupillometry
Using an eye-tracking camera, the investigators will record pupil dilation responses (PDR) induced by both VNS and an oddball paradigm. The PDR signals (measured in arbitrary units and converted to mm) will be aligned with the corresponding stimulus in order to extract the trials. From these, classical PDR metrics such as peak amplitude or latency can be derived.
Measured: Before Implantation, 3 Months, and 6 Months Post Implantation
P300
The P300 component of the evoked potential can be extracted from electroencephalography (EEG) signals as a wave peaking around 300 ms after a given stimulus. An auditory oddball paradigm will be employed as the stimulus. Then, classical metrics will be derived from the P300, such as amplitude and latency.
Measured: Before Implantation, 3 Months, and 6 Months Post Implantation
LMEP
The investigators aim to record a reproducible and quantifiable VNS-induced laryngeal motor-evoked potential (LMEP) from the electromyography (EMG) signal at the larynx level. After filtering the signal, the relevant component that is expected to be observed consists of the artefacts generated by the ON periods of the VNS - each VNS pulse will contain a laryngeal response, which appears right after the VNS pulse. With this laryngeal response detected, the LMEP will be characterised by quantitative features including peak amplitude (μV) and latency (ms).
Measured: Before Implantation, 3 Months, and 6 Months Post Implantation
Secondary outcomes (1)
Response assessment
At 6 months, the seizure frequency reduction will be evaluated compared to 3 months before implantation.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Nov 2026
- Study start28 Feb 2022
- Primary completion1 Sep 2025
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Refractory EpilepsyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cliniques universitaires Saint-Luc- Université Catholique de Louvain
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07909486
- Sponsor's protocol ID
- 2022/10JAN/009
- Acronym
- VNS
- Status last verified
- Oct 2026
- First submitted
- 4 Dec 2023
- Last updated
- 5 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Identification of Biomarkers for Vagus Nerve Stimulation in Patients With Refractory Epilepsy
- ClinicalTrials.gov ID
- NCT07909486
- Acronym / sponsor ID
- VNS / 2022/10JAN/009
- Conditions
- Refractory Epilepsy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Cliniques universitaires Saint-Luc- Université Catholique de LouvainUniversity, hospital or other
- Study start
- 28 Feb 2022 (actual)
- Primary completion
- 1 Sep 2025 (actual)
- Study completion
- Dec 2028 (estimated)
- First posted
- 2 Nov 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A VNS longitudinal study focused on pre and post-VNS implantation in order to predict the VNS response and to understand better mechanisms of VNS using some connectivity and network measures.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| VNS Implanted Group | Experimental | Device: Vagus nerve stimulationThe investigators will compare responders with non-responders to VNS, but both are part of the implanted arm. |
Who may qualify
- Ages
- 18 to 79 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients aged >18 years
- Intelectual Quotient >55 on Wechsler scale (normal or mild cognitive impairment)
- Patients have refractory epilepsy and are planned for VNS implantation
Key exclusion criteria (2 listed)
- Concomitant laryngeal pathology (e.g. recurrent nerve lesions, vocal fold paralysis).
- Dementia/ Neurodegenerative diseases
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Vagus nerve stimulationNo intervention was performed for the study, since VNS is already part of the treatment of these patients. However, VNS parameters are changed for the sake of the study and reestablished at the end. | Device | VNS Implanted Group |
Primary outcome
Pupillometry
Time frame: Before Implantation, 3 Months, and 6 Months Post Implantation
Using an eye-tracking camera, the investigators will record pupil dilation responses (PDR) induced by both VNS and an oddball paradigm. The PDR signals (measured in arbitrary units and converted to mm) will be aligned with the corresponding stimulus in order to extract the trials. From these, classical PDR metrics such as peak amplitude or latency can be derived.
P300
Time frame: Before Implantation, 3 Months, and 6 Months Post Implantation
The P300 component of the evoked potential can be extracted from electroencephalography (EEG) signals as a wave peaking around 300 ms after a given stimulus. An auditory oddball paradigm will be employed as the stimulus. Then, classical metrics will be derived from the P300, such as amplitude and latency.
LMEP
Time frame: Before Implantation, 3 Months, and 6 Months Post Implantation
The investigators aim to record a reproducible and quantifiable VNS-induced laryngeal motor-evoked potential (LMEP) from the electromyography (EMG) signal at the larynx level. After filtering the signal, the relevant component that is expected to be observed consists of the artefacts generated by the ON periods of the VNS - each VNS pulse will contain a laryngeal response, which appears right after the VNS pulse. With this laryngeal response detected, the LMEP will be characterised by quantitative features including peak amplitude (μV) and latency (ms).
1 secondary outcome
Response assessment
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Nov 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Vagus nerve stimulation in people with Refractory Epilepsy, run by Cliniques universitaires Saint-Luc- Université Catholique de Louvain at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 5 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Riëm EL TAHRY, Pr. (+322 764 28 55, riem.eltahry@uclouvain.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pupillometry (time frame: Before Implantation, 3 Months, and 6 Months Post Implantation). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Nov 2026.