EpilepsyPhase 1NCT06016686
Microelectrode Recordings From the Vagus Nerve in Awake Humans
A Phase 1 study testing VNS stimulation and intraneural recordings and Record multi-unit activity from intraneural sites in people with Epilepsy, run by University of Minnesota at 1 site in United States.
Trial summary
This Anchillary project uses a refined technique of ultrasound-guided microneurography of the human cervical vagus nerve, an approach developed by Professor Vaughan Macefield and used safely to-date in 44 prior study participants. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Epilepsy
- What is being tested?
- VNS stimulation and intraneural recordings and Record multi-unit activity from intraneural sites
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Apr 2024to 31 Dec 2026
- Phase
- Phase 1
- 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 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- The participant is greater than or equal to (≥)18 years and is less than or equal to (≤) 40 years of age
- English speaking
- Medicare covered or equivalent health insurance from a partner country
Who cannot join
- Pregnant
- Smokes and is unwilling to abstain from smoking on the day of the experiment.
- Inability or unwillingness to provide written informed consent.
- Individuals with difficulty standing unassisted for 5 minutes during the tilt-table testing
- Individuals found to have a significant carotid artery plaque or intima-media thickness > 1 mm as assessed by ultrasonography during the ultrasound-screening steps of the study visit
- Vagus nerve not visible on ultrasound
- VNS electrodes are not in a suitable location to allow for microelectrode insertion
- Any other clinical reasons deemed by the investigators
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Minnesota
Minneapolis, Minnesota, 55455
Kathryn Vera, PhD, 612-625-5018, giero002@umn.edu
About this study
This Anchillary project uses a refined technique of ultrasound-guided microneurography of the human cervical vagus nerve, an approach developed by Professor Vaughan Macefield and used safely to-date in 44 prior study participants.
The overall goal of this project is to build upon prior data obtained using this approach by undertaking a detailed neurophysiological investigation of the human vagus nerve and to identify the nerve fibers activated during vagal nerve stimulation (VNS) in participants with implanted VNS devices in response to different stimulation parameters. In addition to providing data in unprecedented detail into the physiology of the human vagus nerve, this project will investigate different stimulus intensities, durations and frequencies that differentially excite myelinated and unmyelinated nerve fibers. These results will inform the CSP and guide future development of novel neural interfaces for VNS for various clinical applications.
- Conditions
- Epilepsy
- Being tested
- VNS stimulation and intraneural recordings, Record multi-unit activity from intraneural sites
- Medical subject headings
- Epilepsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VNS stimulation and intraneural recordingsOther
A minimum of three stimulation frequencies (1, 10 and 30 Hz), each up to 60s in duration, will be delivered via the VNS device. Intraneural recordings proximal or distal to the VNS electrodes during delivery of VNS will be performed. Approximately two to five fascicles will be explored in each nerve.
Record multi-unit activity from intraneural sitesOther
Perform a more detailed vagal nerve mapping study by recording from single nerve fibers, including those fibers supplying the heart, lungs, airways and other end-organs. The investigators shall perform functional mapping of the left and right vagus nerves, such as those with cardiac-related and/or respiratory-related neural activity. The research team will also record activity from other nearby fibers to map the differences in neurological behavior in fascicles that control the heart, lungs, airways and other systems.
| Study group | Role | What they receive |
|---|---|---|
| VNS | Experimental | participants with surgically implanted VNS electrodes to treat drug-resistant epilepsy Receives: Other: VNS stimulation and intraneural recordings |
| non-VNS participants | Experimental | participants without implanted VNS devices Receives: Other: Record multi-unit activity from intraneural sites |
What is being measured
The primary outcome is the main question the study is designed to answer.
identify action potential morphology of specific fibers activated by vagal nerve stimulation (VNS)
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module
Measured: 4 hours
identify ratio of myelinated fibers in specific fibers activated by vagal nerve stimulation (VNS)
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. Whether a nerve fiber is (un)myelinated can be determined by visual inspection. Myelinated fibers typically produce "a positive-going narrow spike profile.
Measured: 4 hours
physiological identification of the specific fibers activated by vagal nerve stimulation (VNS)
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. use of tracing and nerve recordings analysis to identify the types of nerves
Measured: 4 hours
identify firing rates of the specific fibers activated by vagal nerve stimulation (VNS)
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. in Hertz
Measured: 4 hours
identify stimulus current required to activate specific fibers activated by vagal nerve stimulation (VNS)
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. in milli-amps
Measured: 4 hours
differences in firing rates of cardiac parasympathetic vagal activity
compare any changes in parasympathetic vagal activity with participants who have not been implanted with a vagal nerve stimulator (Non-VNS Participants).
Labchart; spike histogram module. Unit: Hz.
Measured: 4 hours
Discharge variability of cardiac parasympathetic nerve fibers
Vagal nerve stimulator device. Coefficient of variation, %
Measured: 4 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Aug 2023
- Study start1 Apr 2024
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for 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 1
- Primary purpose
- Supportive care
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Minnesota
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Vaughan G Macefield, PhD, Principal investigator, Monash UniversityJohn Osborn, Principal investigator, University of Minnesota
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06016686
- Sponsor's protocol ID
- VNS
- Status last verified
- Apr 2026
- First submitted
- 10 Jul 2023
- Last updated
- 20 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Microelectrode Recordings From the Vagus Nerve in Awake Humans
- ClinicalTrials.gov ID
- NCT06016686
- Acronym / sponsor ID
- VNS
- Conditions
- Epilepsy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- University of MinnesotaUniversity, hospital or other
- Study start
- 1 Apr 2024 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 30 Aug 2023 (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.
This Anchillary project uses a refined technique of ultrasound-guided microneurography of the human cervical vagus nerve, an approach developed by Professor Vaughan Macefield and used safely to-date in 44 prior study participants.
The overall goal of this project is to build upon prior data obtained using this approach by undertaking a detailed neurophysiological investigation of the human vagus nerve and to identify the nerve fibers activated during vagal nerve stimulation (VNS) in participants with implanted VNS devices in response to different stimulation parameters. In addition to providing data in unprecedented detail into the physiology of the human vagus nerve, this project will investigate different stimulus intensities, durations and frequencies that differentially excite myelinated and unmyelinated nerve fibers. These results will inform the CSP and guide future development of novel neural interfaces for VNS for various clinical applications.
Study design
- Primary purpose
- Supportive care
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| VNS | Experimental | Other: VNS stimulation and intraneural recordingsparticipants with surgically implanted VNS electrodes to treat drug-resistant epilepsy |
| non-VNS participants | Experimental | Other: Record multi-unit activity from intraneural sitesparticipants without implanted VNS devices |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- The participant is greater than or equal to (≥)18 years and is less than or equal to (≤) 40 years of age
- English speaking
- Medicare covered or equivalent health insurance from a partner country
Key exclusion criteria (8 listed)
- Pregnant
- Smokes and is unwilling to abstain from smoking on the day of the experiment.
- Inability or unwillingness to provide written informed consent.
- Individuals with difficulty standing unassisted for 5 minutes during the tilt-table testing
- Individuals found to have a significant carotid artery plaque or intima-media thickness > 1 mm as assessed by ultrasonography during the ultrasound-screening steps of the study visit
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 |
|---|---|---|
| VNS stimulation and intraneural recordingsA minimum of three stimulation frequencies (1, 10 and 30 Hz), each up to 60s in duration, will be delivered via the VNS device. Intraneural recordings proximal or distal to the VNS electrodes during delivery of VNS will be performed. Approximately two to five fascicles will be explored in each nerve. | Other | VNS |
| Record multi-unit activity from intraneural sitesPerform a more detailed vagal nerve mapping study by recording from single nerve fibers, including those fibers supplying the heart, lungs, airways and other end-organs. The investigators shall perform functional mapping of the left and right vagus nerves, such as those with cardiac-related and/or respiratory-related neural activity. The research team will also record activity from other nearby fibers to map the differences in neurological behavior in fascicles that control the heart, lungs, airways and other systems. | Other | non-VNS participants |
Primary outcome
identify action potential morphology of specific fibers activated by vagal nerve stimulation (VNS)
Time frame: 4 hours
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module
identify ratio of myelinated fibers in specific fibers activated by vagal nerve stimulation (VNS)
Time frame: 4 hours
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. Whether a nerve fiber is (un)myelinated can be determined by visual inspection. Myelinated fibers typically produce "a positive-going narrow spike profile.
physiological identification of the specific fibers activated by vagal nerve stimulation (VNS)
Time frame: 4 hours
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. use of tracing and nerve recordings analysis to identify the types of nerves
identify firing rates of the specific fibers activated by vagal nerve stimulation (VNS)
Time frame: 4 hours
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. in Hertz
identify stimulus current required to activate specific fibers activated by vagal nerve stimulation (VNS)
Time frame: 4 hours
assessing vagal nerve activity in epilepsy participants during and in the absence of stimulation. Labchart; spike histogram module. in milli-amps
differences in firing rates of cardiac parasympathetic vagal activity
Time frame: 4 hours
compare any changes in parasympathetic vagal activity with participants who have not been implanted with a vagal nerve stimulator (Non-VNS Participants). Labchart; spike histogram module. Unit: Hz.
Discharge variability of cardiac parasympathetic nerve fibers
Time frame: 4 hours
Vagal nerve stimulator device. Coefficient of variation, %
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 20 Apr 2026.
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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.
Vaughan G Macefield, PhD principal investigator
Monash University
John Osborn principal investigator
University of Minnesota
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing VNS stimulation and intraneural recordings and Record multi-unit activity from intraneural sites in people with Epilepsy, run by University of Minnesota 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 3 inclusion and 8 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 20 Apr 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.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Kathryn Vera, PhD (612-625-5018, giero002@umn.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
identify action potential morphology of specific fibers activated by vagal nerve stimulation (VNS) (time frame: 4 hours). The study lists 7 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 20 Apr 2026.