Effects of Transcutaneous Vagus Nerve Stimulation in Chronic Pain Patients and Healthy Controls

Randomized Trial of Effects of Transcutaneous Vagus Nerve Stimulation in Chronic Pain Patients and Healthy Controls

The tVNS-PP trial investigates the effects of transcutaneous vagus nerve stimulation (tVNS) on autonomic functions, immune responses, and disease severity in chronic pain and restless legs syndrome (RLS) patients as compared to healthy controls.

A pilot study with healthy participants will investigate whether transcutaneous vagus nerve stimulation at the inner tragus reduces heart rate variability and lowers blood pressure without causing undesirable, severe side effects. In addition, changes in immune markers will be analyzed in blood samples before and after the interventions. Patients with primary restless legs syndrome will undergo a similar experimental protocol, except that transcutaneous vagus nerve stimulation will be performed daily. The aim is to determine whether stimulation reduces disease severity and chronic pain while improving quality of life.

Inclusion criteria:

• Male and female participants between 18 and 80 years old
• Written informed consent

Exclusion criteria:

• Age younger than 18 years or older than 80 years
• Participants with somatic or mental comorbidities, especially malignant tumor diseases, cardiac insufficiencies > NYHA II, severe depressive episodes, psychosis or dementia
• Pregnancy or breast feeding
• Addictions to alcohol, medications or drugs (except tobacco)
• An existing legal guardianship
• Participation in another scientific study within the previous eight weeks before enrollment
• Restless Legs Syndrome patients with one of the following secondary predispositions: iron deficiency, polyneuropathy, prolapsed disk, spinal stenosis or chronic obstructive pulmonary disease