NCT05625178

Effects of Vagus Nerve Stimulation on Central Pain Sensitivity & Parasympathetic Function in Knee Osteoarthritis

Investigating Effects of Auricular Vagus Nerve Stimulation on Central Pain Mechanisms, Autonomic Function, and Pain Severity in People With Knee Osteoarthritis

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (actual)
• Sponsor: University of Texas, El Paso · Academic / Other
• Sex: All
• Age: 45 Years – 90 Years
• Healthy volunteers: Not accepted

Summary

The goal of this clinical trial is to test the feasibility and effectiveness of transcutaneous vagus nerve stimulation (tVNS) to the ear on pain and autonomic function in people with knee osteoarthritis (OA). The main questions it aims to answer are: 1) whether tVNS is feasible to be used in people with knee OA; 2) whether tVNS demonstrates the trend in improving knee pain; and 3) whether tVNS has physiological effects on autonomic function (e.g., parasympathetic function) and pain perception in the central nervous system such as brain (i.e., central pain mechanisms). Participants will be asked to complete a battery of self-reported questionnaires about their demographic and behavioral information, ethnicity, pain, sleep, psychological/emotional symptoms. Subsequently, participants will complete baseline assessment where investigators will assess their knee pain severity, central pain sensitivity, and heart rate variability (a measurement for autonomic function). Then participants will receive a 60-minute tVNS. Investigators will redo the same assessment as baseline assessment after tVNS intervention to see the degree of knee pain, central pain sensitivity, and autonomic function changes. At the end of the study, investigators will assess their satisfaction level with the tVNS intervention and the feasibility of the intervention (e.g., completion rate, side effects).

Conditions

• Knee Osteoarthritis
• Central Pain Syndrome

Interventions

Type	Name	Description
DEVICE	Transcutaneous vagus nerve stimulation	tVNS will be performed by the application of an auricular electrode placed at the cymba concha of the left ear. The auricular electrode containing the anode will be applied with a conductive gel without prior disinfection. Once the electrode fits the cymba concha comfortably, the participant will lie down or take a position that is comfortable for them. Once in position, investigators initiate tVNS for 60 minutes with a below-discomfort-threshold intensity with 25 Hz and pulse width 250 uS. The electrical parameters will be modified accordingly to keep the below-discomfort threshold during the intervention.

Timeline

• Start date: 2022-12-15
• Primary completion: 2023-06-03
• Completion: 2023-06-08
• First posted: 2022-11-22
• Last updated: 2025-04-02

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated device study