Auricular Vagus Nerve Stimulation Mechanisms for HIV-Associated Peripheral Neuropathy

September 10, 2026 updated by: Marlon Wong, University of Miami

Mechanistic Modulation of HIV-Associated Peripheral Neuropathy in Older Adults Via Auricular Vagus Nerve Stimulation

This study looks at a non-invasive ear stimulation treatment to better understand nerve pain in people living with HIV. The study aims to assess how the body and nervous system respond to this treatment, including changes in heart function and pain signals. The goal is to learn how future treatments for nerve pain may be improved.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

70

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Florida
      • Miami, Florida, United States, 33136
        • Christine E Lynn Rehabilitation Center
        • Contact:
        • Principal Investigator:
          • Marlon L. Wong, PT, PhD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Established HIV infection
  • Glove/stocking dysesthesias lasting for ≥3 months
  • HIV-associated peripheral neuropathy (HIV-PN) related symptoms ≥4 (on a scale of 0-10) within the last week
  • Stable medical care (i.e., no changes in Antiretroviral Therapy or pain medication within 2 months of enrollment)
  • Able to read the consent form, demonstrate understanding of study procedures and requirements, and independently provide written informed consent

Exclusion Criteria:

  • Unstable cardiac disease
  • Implanted electronic or magnetic devices (e.g., pacemaker, cochlear implants, medication pumps, and other implanted neurostimulation systems)
  • Head or neck cancer or metastases
  • Recent ear trauma or metal implants in the head
  • History of epilepsy, unprovoked seizure, stroke, brain tumor, significant traumatic brain injury, prior intracranial surgery, or other neurological condition associated with increased seizure risk
  • Active or uncontrolled comorbidities that independently cause neuropathy (e.g., recent chemotherapy, uncontrolled diabetes with documented neuropathic complications)
  • Clinical evidence of non-HIV neuropathy (e.g., neuropathic symptoms predating HIV diagnosis, uncontrolled diabetes)
  • Known allergy to tape/adhesive
  • Ferromagnetic or non-MRI-compatible metal in the head, neck, eye, or cranial region, including aneurysm clips, retained metal fragments, bullets, shrapnel, or other metallic implants not demonstrated to be TMS-compatible.
  • Pregnancy or actively breast feeding

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Auricular Vagus Nerve (AVNS) Group
Participants in this group will receive 6 sessions of transcutaneous auricular vagus nerve stimulation (AVNS) over 2 weeks. Each stimulation session will last approximately 90 minutes at monophasic pulses.
Device: Transcutaneous Auricular Vagus Nerve Stimulation (AVNS)
Transcutaneous auricular vagus nerve stimulation (taVNS) will be administered at the cymba concha using hydrogel electrodes and a Digitimer DS8R biphasic constant-current stimulator. Participants will receive 90-minute stimulation sessions consisting of monophasic pulses (pulse width: 500 microseconds; frequency: 25 Hz; duty cycle: 50%). Stimulation intensity will be set at 200% of the participant's sensory perception threshold and may be adjusted up to 5 milliamperes (mA) while remaining below the pain threshold.
Other Names:
  • Digitimer DS8R
No Intervention: Waitlist Control
Participants in this group will not receive an intervention. Participants will be placed on a waitlist to try the intervention and will be assessed pre and post the 2-week waiting period. No stimulation device is provided, and no active treatment or experimental procedure is administered during the 14-day waitlist period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Short Interval intraCortical Inhibition (SICI)
Time Frame: Baseline (Day 0), Post-trial (Day 14)
Short-interval intracortical inhibition (SICI) will be assessed using paired-pulse transcranial magnetic stimulation (TMS) with a MagPro X100 stimulator. Change in SICI will be calculated as the difference between post-intervention and pre-intervention measurements. Negative values indicate increased intracortical inhibition.
Baseline (Day 0), Post-trial (Day 14)
Change in Root Mean Square of Successive Differences (RMSSD)
Time Frame: (Days 1-13), Post-trial (Day 14)
The root mean square of successive differences (RMSSD), will be assessed using a three-lead electrocardiogram (ECG). Change in RMSSD will be calculated as the difference between post-intervention and baseline measurements. Higher RMSSD values indicate greater parasympathetic (vagal) activity and heart rate variability.
(Days 1-13), Post-trial (Day 14)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Neuropathic Pain Symptom Severity (NPSI)
Time Frame: Baseline (Day 0), post-trial (Day 14)
Neuropathic pain symptom severity will be assessed using the Neuropathic Pain Symptom Inventory (NPSI), a patient-reported questionnaire that evaluates 10 neuropathic pain symptoms on an 11-point numeric scale ranging from 0 (no symptom) to 10 (worst symptom severity imaginable). The NPSI also includes 2 items assessing the duration of ongoing pain and the frequency of pain attacks. Higher scores indicate greater neuropathic pain symptom severity.
Baseline (Day 0), post-trial (Day 14)
Change in Neuropathic Symptom Intensity (Numeric Rating Scale)
Time Frame: Baseline (Day 0), pre/post each treatment session (Days 1-13), post-trial (Day 14), and at follow up (Day 45)
Neuropathic symptom intensity will be assessed using the 0-10 Numeric Rating Scale (NRS). Participants will rate the average severity of HIV-associated peripheral neuropathy symptoms from 0 (not bothersome) to 10 (worst imaginable). Higher scores indicate greater symptom intensity.
Baseline (Day 0), pre/post each treatment session (Days 1-13), post-trial (Day 14), and at follow up (Day 45)
Change in Serum Neurofilament Light Chain (NfL)
Time Frame: Baseline (Day 0), Post-trial (Day 14)
Serum neurofilament light chain (NfL) will be measured from non-fasted venous blood samples. NfL concentrations (pg/mL) will be quantified using enzyme-linked immunosorbent assay (ELISA). Change in NfL will be calculated as the difference between post-intervention and baseline serum concentrations. Higher concentrations indicate greater neuroaxonal injury.
Baseline (Day 0), Post-trial (Day 14)
Change in Serum Interleukin-1 Beta (IL-1β)
Time Frame: Baseline (Day 0), Post-trial (Day 14)
Serum interleukin-1 beta (IL-1β) will be measured from non-fasted venous blood samples. IL-1β concentrations (pg/mL) will be quantified using enzyme-linked immunosorbent assay (ELISA). Change in IL-1β will be calculated as the difference between post-intervention and baseline serum concentrations. Higher concentrations indicate greater systemic inflammation.
Baseline (Day 0), Post-trial (Day 14)
Change in Serum Tumor Necrosis Factor-Alpha (TNF-α)
Time Frame: Baseline (Day 0), Post-trial (Day 14)
Serum Tumor Necrosis Factor-Alpha (TNF-α) will be measured from non-fasted venous blood samples. TNF-α concentrations (pg/mL) will be quantified using enzyme-linked immunosorbent assay (ELISA). Change in TNF-α will be calculated as the difference between post-intervention and baseline serum concentrations. Higher concentrations indicate greater systemic inflammation.
Baseline (Day 0), Post-trial (Day 14)
Change in Wind-Up Ratio (WUR)
Time Frame: Baseline (Day 0), Pre/post each treatment session (Days 1-13), Post-trial (Day 14)
Wind-up ratio (WUR), will be assessed using responses to repeated pinprick stimuli. Change in WUR will be calculated as the difference between post-intervention and baseline measurements. Lower WUR values indicate reduced temporal summation and decreased central sensitization.
Baseline (Day 0), Pre/post each treatment session (Days 1-13), Post-trial (Day 14)
Change in Conditioned Pain Modulation (CPM)
Time Frame: Baseline (Day 0), Post-trial (Day 14)
Conditioned pain modulation (CPM), will be assessed using a cold pressor conditioning stimulus (1 to 4°C for 60 seconds) and pressure pain threshold (PPT) testing on the forearm. The CPM effect will be calculated as the percent change in PPT from before to after the conditioning stimulus (%ΔPPT). Higher CPM values indicate greater endogenous pain inhibition.
Baseline (Day 0), Post-trial (Day 14)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Miami

Investigators

  • Principal Investigator: Marlon L. Wong, PT, PhD, University of Miami

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

November 1, 2026

Primary Completion (Estimated)

August 30, 2028

Study Completion (Estimated)

September 30, 2028

Study Registration Dates

First Submitted

September 10, 2026

First Submitted That Met QC Criteria

September 10, 2026

First Posted (Actual)

September 16, 2026

Study Record Updates

Last Update Posted (Actual)

September 16, 2026

Last Update Submitted That Met QC Criteria

September 10, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 20260653
  • 1R21NS149935-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified participant-level clinical, physiological, biomarker, and patient-reported outcome data underlying published study findings.

IPD Sharing Time Frame

By publication of primary study findings or no later than the end of the award period

IPD Sharing Access Criteria

The study protocol, statistical analysis plan, informed consent form template, and analytic code will be made available upon publication of the primary results or study completion, consistent with the approved NIH Data Management and Sharing Plan. Materials will be shared through appropriate repositories and/or institutional platforms in accordance with participant privacy protections and applicable policies.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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