EpilepsyNCT05395026
Systematic Evaluation of VNS Parameters
A study testing electrical stimulation of vagus nerve in people with Epilepsy, run by Duke University at 1 site in United States.
Trial summary
The goal of this study is to measure the activation of the vagus nerve and the side effects of vagus nerve stimulation (VNS) (neck muscle contractions, changes in heart rate) across a range of stimulation parameters typically used in VNS therapy for epilepsy (pulse durations, pulse amplitudes, pulse repetition rates). Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Epilepsy
- What is being tested?
- electrical stimulation of vagus nerve
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Nov 2022to 23 Jul 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- adult epilepsy patients undergoing VNS electrode implantation or implanted pulse generator (IPG) replacement surgery
- in good health
- neurologically stable aside from epilepsy
- able to provide informed consent
Who cannot join
- patients with another implanted electrical device (besides VNS)
- a history of heart conditions that the surgeon considers a contraindication to study participation
Trial locations and contacts
1 site in 1 country.
United States1 site
Duke University Medical Center
Durham, North Carolina, 27710
About this study
Official title: Systematic Evaluation of Vagus Nerve Stimulation Parameters on Cardiac Rhythm, Laryngeal Muscle Electromyography, and Vagus Nerve Activation in Acute and Chronic Implantations
The goal of this study is to measure the activation of the vagus nerve and the side effects of vagus nerve stimulation (VNS) (neck muscle contractions, changes in heart rate) across a range of stimulation parameters typically used in VNS therapy for epilepsy (pulse durations, pulse amplitudes, pulse repetition rates). This mapping of the parameter space may inform future device programming to improve electrical activation of the vagus nerve and/or to reduce side effects, and it may be used for validation of computational models. The study will recruit adult participants with epilepsy who are undergoing surgery either for an initial implant of a VNS device or for replacement of the implanted pulse generator (IPG) due to battery depletion. During surgery, the study will involve stimulating the vagus nerve via the standard implanted clinical VNS electrodes over a range of stimulation parameters while recording the activity of the vagus nerve (electroneurogram (ENG)), electromyogram (EMG) response of neck/throat muscles, and the heart rate (electrocardiogram (EKG)). Stimulation parameters will be within the ranges used for clinical therapy and below limits established for non-damaging electrical stimulation.
Read the detailed description
This study will recruit adult participants with epilepsy who are undergoing planned surgery either for an initial implant of a vagus nerve stimulation (VNS) device or for replacement of their VNS implanted pulse generator (IPG) due to battery depletion. The primary study goals are to measure the activation of the vagus nerve and the side effects of vagus nerve stimulation (neck muscle contractions, changes in heart rate) across a range of stimulation parameters typically used in VNS therapy for epilepsy. This mapping of the parameter space may inform future device programming to improve electrical activation of the vagus nerve and/or to reduce side effects. All study participants will be assigned to a single study group and will complete the same study procedures.
The research study will take place during VNS surgery. For participants undergoing a first VNS implant surgery, once the vagus nerve is exposed and before placing the VNS electrodes, the investigators may image the nerve with ultrasound. Mapping of the parameter space will then occur after placement of the cuff electrodes around the cervical vagus nerve for participants undergoing a first VNS implant surgery or removal of the IPG with the depleted battery for patients undergoing IPG replacement surgery. Temporary sterile extension wires will connect the implanted VNS electrode to the research stimulation system. Research procedures will involve stimulating the vagus nerve through the standard implanted clinical VNS electrodes over a range of stimulation parameters. At the same time, the investigators will record how changes in stimulation affect the activity of the vagus nerve (measured by electroneurogram (ENG)), the response of the neck and throat muscles (by electromyogram (EMG)) and the heart rate (by electrocardiogram (EKG)). Several stimulation trials will be conducted with different VNS parameters (pulse duration, pulse amplitude, and pulse repetition rate) delivered in randomized order. Stimulation parameters will be within the ranges used for clinical therapy and will not exceed those that produce a 25% reduction in heart rate. Measurements will be made during 10 to 60 second trials, in which stimulation will be off for the first section (baseline), on for the second section (responses to stimulation), and off for the final section (recovery). The stimulus waveform will be a charge-balanced biphasic pulse, with values of charge density (D) limited to values below the nondamaging limits that are well-established in literature.
- Conditions
- Epilepsy
- Being tested
- electrical stimulation of vagus nerve
- Medical subject headings
- Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
electrical stimulation of vagus nerveOther
VNS electrical stimulation parameters (pulse duration, pulse amplitude, and pulse frequency) will be systematically changed to determine the effect on vagus nerve activation, laryngeal muscle contraction, and heart rate.
| Study group | Role | What they receive |
|---|---|---|
| Investigational Stimulation Parameters | Experimental | Not described Receives: Other: electrical stimulation of vagus nerve |
What is being measured
The primary outcome is the main question the study is designed to answer.
stimulation amplitude threshold
The stimulation amplitude threshold is the amplitude when vagus nerve stimulation (VNS) activates the laryngeal muscles and has potential to cause subject discomfort during stimulation. The stimulation amplitude threshold will be measured with the NIM-EMG endotracheal tube recording, and the threshold will be determined as the amplitude that causes the first evoked potential in the laryngeal muscles.
Measured: During procedure (30 minutes)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 May 2022
- Study start28 Nov 2022
- Primary completion23 Jul 2024
- Study completion23 Jul 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for EpilepsyStudies of the same condition, open and under way.
- More trials run by Duke UniversityThe sponsor's other registered studies.
- 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- Duke University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Warren M Grill, PhD, Principal investigator, Duke University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05395026
- Sponsor's protocol ID
- Pro00103473
- Status last verified
- Mar 2026
- First submitted
- 18 May 2022
- Last updated
- 9 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Cogan SF, Ludwig KA, Welle CG, Takmakov P. Tissue damage thresholds during therapeutic electrical stimulation. J Neural Eng. 2016 Apr;13(2):021001. doi: 10.1088/1741-2560/13/2/021001. Epub 2016 Jan 20.
PubMed 26792176Kumsa D, Steinke GK, Molnar GF, Hudak EM, Montague FW, Kelley SC, Untereker DF, Shi A, Hahn BP, Condit C, Lee H, Bardot D, Centeno JA, Krauthamer V, Takmakov PA. Public Regulatory Databases as a Source of Insight for Neuromodulation Devices Stimulation Parameters. Neuromodulation. 2018 Feb;21(2):117-125. doi: 10.1111/ner.12641. Epub 2017 Aug 7.
PubMed 28782181Turk KM, Mohsenian KJ, Peters JJ, Southwell DG, Grill WM, Pelot NA. Intraoperative Laryngeal Muscle and Heart Rate Responses to Implanted Vagus Nerve Stimulation. Neuromodulation. 2026 Apr 22:S1094-7159(26)00064-4. doi: 10.1016/j.neurom.2026.02.010. Online ahead of print.
PubMed 42024053
Study at a glance
From the registry record, last updated by the sponsor on 9 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Systematic Evaluation of Vagus Nerve Stimulation Parameters on Cardiac Rhythm, Laryngeal Muscle Electromyography, and Vagus Nerve Activation in Acute and Chronic Implantations
- ClinicalTrials.gov ID
- NCT05395026
- Acronym / sponsor ID
- Pro00103473
- Conditions
- Epilepsy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- Duke UniversityUniversity, hospital or other
- Study start
- 28 Nov 2022 (actual)
- Primary completion
- 23 Jul 2024 (actual)
- Study completion
- 23 Jul 2024 (actual)
- First posted
- 27 May 2022 (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.
The goal of this study is to measure the activation of the vagus nerve and the side effects of vagus nerve stimulation (VNS) (neck muscle contractions, changes in heart rate) across a range of stimulation parameters typically used in VNS therapy for epilepsy (pulse durations, pulse amplitudes, pulse repetition rates). This mapping of the parameter space may inform future device programming to improve electrical activation of the vagus nerve and/or to reduce side effects, and it may be used for validation of computational models. The study will recruit adult participants with epilepsy who are undergoing surgery either for an initial implant of a VNS device or for replacement of the implanted pulse generator (IPG) due to battery depletion. During surgery, the study will involve stimulating the vagus nerve via the standard implanted clinical VNS electrodes over a range of stimulation parameters while recording the activity of the vagus nerve (electroneurogram (ENG)), electromyogram (EMG) response of neck/throat muscles, and the heart rate (electrocardiogram (EKG)). Stimulation parameters will be within the ranges used for clinical therapy and below limits established for non-damaging electrical stimulation.
Detailed description
This study will recruit adult participants with epilepsy who are undergoing planned surgery either for an initial implant of a vagus nerve stimulation (VNS) device or for replacement of their VNS implanted pulse generator (IPG) due to battery depletion. The primary study goals are to measure the activation of the vagus nerve and the side effects of vagus nerve stimulation (neck muscle contractions, changes in heart rate) across a range of stimulation parameters typically used in VNS therapy for epilepsy. This mapping of the parameter space may inform future device programming to improve electrical activation of the vagus nerve and/or to reduce side effects. All study participants will be assigned to a single study group and will complete the same study procedures.
The research study will take place during VNS surgery. For participants undergoing a first VNS implant surgery, once the vagus nerve is exposed and before placing the VNS electrodes, the investigators may image the nerve with ultrasound. Mapping of the parameter space will then occur after placement of the cuff electrodes around the cervical vagus nerve for participants undergoing a first VNS implant surgery or removal of the IPG with the depleted battery for patients undergoing IPG replacement surgery. Temporary sterile extension wires will connect the implanted VNS electrode to the research stimulation system. Research procedures will involve stimulating the vagus nerve through the standard implanted clinical VNS electrodes over a range of stimulation parameters. At the same time, the investigators will record how changes in stimulation affect the activity of the vagus nerve (measured by electroneurogram (ENG)), the response of the neck and throat muscles (by electromyogram (EMG)) and the heart rate (by electrocardiogram (EKG)). Several stimulation trials will be conducted with different VNS parameters (pulse duration, pulse amplitude, and pulse repetition rate) delivered in randomized order. Stimulation parameters will be within the ranges used for clinical therapy and will not exceed those that produce a 25% reduction in heart rate. Measurements will be made during 10 to 60 second trials, in which stimulation will be off for the first section (baseline), on for the second section (responses to stimulation), and off for the final section (recovery). The stimulus waveform will be a charge-balanced biphasic pulse, with values of charge density (D) limited to values below the nondamaging limits that are well-established in literature.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Investigational Stimulation Parameters | Experimental | Other: electrical stimulation of vagus nerve |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- adult epilepsy patients undergoing VNS electrode implantation or implanted pulse generator (IPG) replacement surgery
- in good health
- neurologically stable aside from epilepsy
- able to provide informed consent
Key exclusion criteria (2 listed)
- patients with another implanted electrical device (besides VNS)
- a history of heart conditions that the surgeon considers a contraindication to study participation
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 |
|---|---|---|
| electrical stimulation of vagus nerveVNS electrical stimulation parameters (pulse duration, pulse amplitude, and pulse frequency) will be systematically changed to determine the effect on vagus nerve activation, laryngeal muscle contraction, and heart rate. | Other | Investigational Stimulation Parameters |
Primary outcome
stimulation amplitude threshold
Time frame: During procedure (30 minutes)
The stimulation amplitude threshold is the amplitude when vagus nerve stimulation (VNS) activates the laryngeal muscles and has potential to cause subject discomfort during stimulation. The stimulation amplitude threshold will be measured with the NIM-EMG endotracheal tube recording, and the threshold will be determined as the amplitude that causes the first evoked potential in the laryngeal muscles.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Mar 2026.
- Background: PubMed 26792176Cogan SF, Ludwig KA, Welle CG, Takmakov P. Tissue damage thresholds during therapeutic electrical stimulation. J Neural Eng. 2016 Apr;13(2):021001. doi: 10.1088/1741-2560/13/2/021001. Epub 2016 Jan 20.
- Background: PubMed 28782181Kumsa D, Steinke GK, Molnar GF, Hudak EM, Montague FW, Kelley SC, Untereker DF, Shi A, Hahn BP, Condit C, Lee H, Bardot D, Centeno JA, Krauthamer V, Takmakov PA. Public Regulatory Databases as a Source of Insight for Neuromodulation Devices Stimulation Parameters. Neuromodulation. 2018 Feb;21(2):117-125. doi: 10.1111/ner.12641. Epub 2017 Aug 7.
- Derived from this study: PubMed 42024053Turk KM, Mohsenian KJ, Peters JJ, Southwell DG, Grill WM, Pelot NA. Intraoperative Laryngeal Muscle and Heart Rate Responses to Implanted Vagus Nerve Stimulation. Neuromodulation. 2026 Apr 22:S1094-7159(26)00064-4. doi: 10.1016/j.neurom.2026.02.010. Online ahead of print.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Warren M Grill, PhD principal investigator
Duke University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing electrical stimulation of vagus nerve in people with Epilepsy, run by Duke University at 1 site in United States.
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 4 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: finished, as of the sponsor's last update on 9 Mar 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 United States. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
stimulation amplitude threshold (time frame: During procedure (30 minutes)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05395026, which also lists 3 linked publications.
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 9 Mar 2026.