Tonic Pain and Transauricular Vagal Nerve Stimulation

Aalborg University

Status: Enrolling

Conditions: Experimental Pain in Healthy Human Subjects

Treatments: Device: Earlobe Stimulation; Device: taVNS; Device: Sham (No Treatment)

Study type: Interventional

Funder types: Other

Identifiers

NCT07325058

N-20230022-5

Details and patient eligibility

About

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.

Full description

Across 3 visits, each lasting around 2.5hours, burst-taVNS (electrical stimulation of the concha cymba) will be compared to active-control (electrircal stimulation of the earlobe) and sham (no current) stimulation, two gold-standard controls. Assessments of outcomes will occur before capsaicin application and before, twice during and after electrical ear stimulation.

Enrollment: 36 estimated patients

Sex: All

Ages: 16 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy
• Speak and understand English
• 18-60 years old.

Exclusion criteria

• 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)
• Recent history of acute pain particularly in the lower limbs
• Abnormally disrupted sleep in 24 hours preceding experiment
• Contraindications to electric stimulation application (history of epilepsy, metal implants in head or jaw, etc.)
• Lack of ability to cooperate
• Contraindications for capsaicin including an intolerance chili consumption and burns or wounds to the application site.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Triple Blind

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36 participants in 3 patient groups, including a placebo group

taVNS

Experimental group

Description:

Bursts of 25Hz occuring for 3.4sec every 29.4sec for 40min.

Treatment:

Device: taVNS

Earlobe Stimulation

Active Comparator group

Description:

Bursts of 25Hz occuring for 3.4sec every 29.4sec for 40min.

Treatment:

Device: Earlobe Stimulation

Sham

Placebo Comparator group

Description:

No stimulation.

Treatment:

Device: Sham (No Treatment)