Health TrialsbyHealthPanel

Tonic Pain and Transauricular Vagal Nerve Stimulation

ConditionExperimental Pain in Healthy Human Subjects
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age16-60
SponsorAalborg University

About this trial

This study aims to explore the effect of burst-taVNS (electric stimulation of the concha cymba) on tonic (capsaicin-induced skin pain) and acute (pressure pain sensitivity) experimental pain and cardioception. Primary outcomes include pain intensity. Secondary outcomes include sensory thresholds, resting heart rate (EKG), pupillary measurements and conditioned pain modulation.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Healthy

Speak and understand English

18-60 years old.

Disqualifiers

Pregnant and/or breastfeeding

Regular use of cannabis, opioids or other drugs

Current or previous neurologic, musculoskeletal, mental, or other illnesses (e.g., brain or spinal cord injuries, degenerative neurological disorders, major depression, cardiovascular disease, chronic lung disease, etc.)

Current regular (once or more a week) use of analgesic medication or other medication which may affect the trial (including paracetamol and NSAIDs)

Trial design

Design model

Crossover

Treatments tested in this trial

  • taVNS

    Device

    Two-headed ball-point electrode which is placed in the concha cymba.

  • Earlobe Stimulation

    Device

    Circular urface adhering electrodes will be attached to either facet of the earlobe.

  • Sham (No Treatment)

    Device

    Circular surface adhesive electrodes will be placed on either facet of the earlobe. No current will pass through the electrodes.

Treatment groups

36 Participants
are divided into 3 treatment groups
Group A: taVNSExperimental treatment 1 intervention
Group B: Earlobe StimulationActive comparator 1 intervention
Group C: ShamPlacebo comparator 1 intervention

Trial outcomes

Primary outcomes

1

Pain Intensity

Capaisin is a topically administered tonic pain model. Stemming from its chilly-origin, pain induced ressembels heat/light burning sensation which increases within 20minute of application to the forearm, before it plateaus. Associated pain can be stopped immediately by applying ice/cold water. Participants will be asked to rate (using a scale from 0 denoting no pain, to 10 denoting maximal pain) the intensity of the pain in 5 min time intervals.

Time frame
From when capsaicin is applied to the end of the experiment in 5 min intervals.

Secondary outcomes

1

Pressure Pain Detection Threshold

Using the computerized pressure pain algometer tool (Nocitech, Aalborg, Denmark), cuffs placed on the calves of participants wll inflate at a consistent rate. Participants are instructed to rate the pain experiences using a visual analogue scale (VAS) and to press a button when the pain becomes intolerable. The VAS ranges from 0 denoting no pain, to 10 denoting maximal pain. Pain detection, namely the kPa where the VAS is at 1cm, and the pain tolerance, namely the kPa when the deflation-button is pressed, will be acquired.

Time frame
Before Capsaicin application and at 3 time intervals from when the ear stimulation (taVNS, Active Control or Sham) is applied: before, as the stimulation starts and halfway during (at min 20).
2

Conditioned Pain Modulation Effect

Using the computerized pressure pain algometer tool (Nocitech, Aalborg, Denmark), cuffs placed on the calves of participants wll inflate at a consistent rate. Whilst participants have a constant pressure applied to their non-dominant leg, they are instructed to rate the pain experienced on the dominant leg as the cuff slowly inflates using a visual analogue scale (VAS) and to press a button when the pain becomes intolerable. The VAS ranges from 0 denoting no pain, to 10 denoting maximal pain. Conditioned pain detection, namely the kPa where the VAS is at 1cm, will be acquired.

Time frame
Before Capsaicin application and at 3 time intervals from when the ear stimulation (taVNS, Active Control or Sham) is applied: before, as the stimulation starts and halfway during (at min 20).
3

Pressure Pain Perception

Trapezius pressure pain perception will be acquired using a handheld pressure algometer (Somedic, Solna, Sweden). Perpendicular to the musle and halfway between the acrominion and the processus spinous vertebrae, the 1cm2 probe will be applied at a constant rate. When particpants first feel pressure pain, they will respond with a button-press.

Time frame
Before Capsaicin application and at 3 time intervals from when the ear stimulation (taVNS, Active Control or Sham) is applied: before, as the stimulation starts and halfway during (at min 20).
4

Pupillary Light Reflex

Using the Neurolight, per pupil, a 3s light reflex will be acquired. This refers to the reflex following the exposure to a light flash.

Time frame
Before Capsaicin application and at 3 time intervals from when the ear stimulation (taVNS, Active Control or Sham) is applied: before, as the stimulation starts and halfway during (at min 20).

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Aalborg University

Lead sponsor

Source ClinicalTrials.gov
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