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.
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)
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
Parallel
Transcutaneous Auricular Vagus Nerve Stimulation (AVNS)
DeviceTranscutaneous 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.
Change in Short Interval intraCortical Inhibition (SICI)
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.
Change in Root Mean Square of Successive Differences (RMSSD)
The root mean square of successive differences (RMSSD), will be assessed using a three-lead electrocardiogram (ECG) and reported in milliseconds (ms). Higher RMSSD values indicate greater parasympathetic (vagal) activity and heart rate variability.
Change in Neuropathic Pain Symptom Severity Inventory (NPSI)
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.
Change in Neuropathic Symptom Intensity (Numeric Rating Scale)
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.
Change in Serum Neurofilament Light Chain (NfL)
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.
Change in Serum Interleukin-1 Beta (IL-1β)
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.
Click on the lead sponsor to view all of their trials.
University of Miami
Lead sponsor
National Institute of Neurological Disorders and Stroke (NINDS)
Collaborator
