The Combined Effect of TENS and TaVNS on Pressure and Heat Pain Thresholds in Pain-Free Subjects

Healthy Volunteers Clinical Trial

Official title:

The Combined Effect of Transcutaneous Electrical Nerve Stimulation and Transcutaneous Auricular Vagus Nerve Stimulation on Pressure and Heat Pain Thresholds in Pain-Free Subjects: A Randomized Cross-Over Trial

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT06361381
• Other study ID #: 24-01-281
• Status: Not yet recruiting
• Phase: N/A
• Start date: April 2024
• Est. completion date: December 2024

Study information

• Verified date: April 2024
• Source: University of Hartford
• Contact: Richard E Liebano, PhD
• Phone: 8607685181
• Email: liebano[@]hartford.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive modality that utilizes electrical currents to modulate pain in populations with acute and chronic pain. TENS has been demonstrated to produce hypoalgesic effects in postoperative pain, fibromyalgia, knee osteoarthritis, and healthy subjects. Transcutaneous auricular vagus nerve stimulation (TaVNS) is a non-invasive modality that modulates the vagus nerve by stimulating its auricular branches. The effects of the combination of TENS and TaVNS on producing an analgesic response have not been studied. Considering that TENS and TaVNS both stimulate similar analgesic pathways but through different means of activation, the investigators can hypothesize that a combination of both methods can produce a more pronounced analgesic response. Therefore, the objective of this study is to assess the hypoalgesic effect of a combination of TENS and TaVNS in pain-free subjects.

The study will be a simple crossover design conducted at the University of Hartford. Subjects will be recruited from the University of Hartford population via oral communication, digital flyers, and posters on campus. Thirty participants will undergo two sessions in a crossover manner with one week in between. During one session, the participants will receive TENS with active TaVNS and the other session will be a placebo procedure (TENS with placebo TaVNS). The order of these sessions will be randomized. Importantly, the pressure pain threshold (PPT) and heat pain threshold (HPT) assessors will be blinded to the treatment category. For active TaVNS, a frequency of 25 Hz will be applied with a pulse duration of 200 µs. For placebo TaVNS, the intensity will be increased to a sensory level and then decreased to 0 mA. High frequency TENS of 100Hz will be applied in both sessions, with a pulse duration of 200 µsec, asymmetrical biphasic square waveform, and intensity of maximal tolerance without pain. TENS and TaVNS will be turned on for 30 minutes after a baseline measurement of outcomes. TENS and TaVNS will then be turned off, but the electrodes will remain on until completion of post-treatment assessment. Pressure pain threshold, heat pain threshold, blood pressure, oxygen saturation and heart rate will be tested 4 times: Once pre-intervention, once during intervention, once immediately after the intervention and once 15 minutes post-intervention.

Description:

The study will be a simple crossover design with the following two treatments: (1) active TaVNS and (2) placebo TaVNS. Each subject will receive both interventions in random order.

Pressure and Heat pain thresholds will be recorded at baseline, 15 min, 30 min, and 45 min.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 30
• Est. completion date: December 2024
• Est. primary completion date: June 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 40 Years

Eligibility

Inclusion Criteria:

• Absence of pain

• Age 18-40

• Men and women

Exclusion Criteria:

• Neurological diseases

• Severe cardiorespiratory disease

• Pregnancy

• Skin infection or lesions or change in sensation at the TENS or TaVNS application site

• Cancer

• Cardiac pacemaker

• Allergy to electrodes

• Chronic illness or pain

• Use of drugs that affect pain or vagal tone in the past 48 hours prior to data collection

Related Conditions & MeSH terms

• Healthy Volunteers

Intervention

Device:
• Active Transcutaneous Auricular Vagus Nerve Stimulation (TaVNS)
Both concha will be swabbed with an alcohol wipe before applying a thin layer of conductive gel. An ear clip electrode will be placed in the concha of both ears. A frequency of 25 Hz will be applied with a pulse duration of 200 µs. Every 5 minutes, the subject will be asked if the intensity can be increased, decreased or remain the same to maintain the same level of intensity. Participants will also receive active TENS, 100 Hz, 200 µsec on forearm.
• Placebo Transcutaneous Auricular Vagus Nerve Stimulation (TaVNS)
For placebo TaVNS, the intensity will be increased to a sensory level and then decreased to 0 mA. Participants will also receive active TENS, 100 Hz, 200 µsec on forearm.
• Transcutaneous Electrical Nerve Stimulation
TENS will be applied on subject's forearm at a strong but comfortable intensity

Locations

Country	Name	City	State
United States	University of Hartford	West Hartford	Connecticut

Sponsors (1)

Lead Sponsor	Collaborator
University of Hartford

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Pressure Pain Threshold	A digital pressure algometer will measure the pain threshold to deep mechanical stimuli in kPa	2 weeks
Secondary	Heat Pain Threshold	Superficial heat pain sensitivity, in degree Celsius, will be assessed using a handheld thermode.	2 weeks
Secondary	Heart rate	Heart rate (beats per minute) will be assessed using a fingertip pulse oximeter	2 weeks
Secondary	Oxygen saturation	Oxygen saturation in percentage will be assessed using a fingertip pulse oximeter	2 weeks
Secondary	Blood pressure	Blood pressure in millimeters of mercury will be assessed using a upper arm cuff, blood pressure monitor	2 weeks