The Combined Effect of TENS and TaVNS on Pressure and Heat Pain Thresholds in Pain-Free Subjects - Trial NCT06361381

Timeline & Enrollment

Primary Outcome

Pressure Pain Threshold

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.

ICD-10 Classifications