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

Not Applicable

Active, not recruiting

• Conditions: Chronic Pain; Restless Legs Syndrome
• Interventions: Device: Transcutaneous vagus nerve stimulation

• Registration Number: NCT05007743
• Lead Sponsor: University Medical Center Goettingen

Brief Summary

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.

Detailed Description

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.

Study Timeline

• Study Start: 2019-07-21
• Study First Submitted: 2021-07-15
• Study First Submitted QC: 2021-08-09
• Study First Posted: 2021-08-16
• Status Verified: 2023-05
• Last Update Submitted: 2023-05-09
• Last Update Posted: 2023-05-10
• Primary Completion: 2023-08
• Study Completion: 2023-08

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Stimulation of inner tragus	Transcutaneous vagus nerve stimulation	Comparing autonomic hemodynamic functions and immune responses pre- and post-stimulation of the vagus nerve
Stimulation of ear lobe	Transcutaneous vagus nerve stimulation	Comparing autonomic hemodynamic functions and immune responses pre- and post-stimulation of the vagus nerve

Primary Outcome Measures

Name	Time	Method
Spectral analysis of heart rate variability	Two days	The normalized high frequency component of the RR intervals (HF-HRV) is expressed as a percentage.
Spontaneous baroreceptor sensitivity	Two days	The average baroreceptor sensitivity in ms/mmHg.
Time domain analysis of heart rate variability	Two days	The standard deviation of the RR intervals (SDNN) and the root mean square of successive differences (RMSSD) in milliseconds.
International RLS Severity Scale	Seven days	Numeric score quantifying disease severity. This numeric rating scale ranges from 0 to 40 points.; The higher the achieved score, the higher is the RLS disease severity. 0 points: no symptoms, 1-10 points: mild symptoms, 11-20 points: moderate symptoms, 21-30 points: severe symptoms, 31-40 points: extreme symptoms

Secondary Outcome Measures

Name	Time	Method
Sudoscan	Two days	Measurement of electrochemical skin conductance
Hospital Anxiety and Depression scale	Two days	This questionnaire has 14 items that evaluate depression and anxiety symptoms. Each item has four possible responses and is scored in a range from zero to three with higher scores representing more symptoms.
Median nerve stimulation	Two days	Electrical nerve stimulation of the median nerve to assess its strength-duration time constant (SDTC) or chronaxie in milliseconds. The SDTC is a measure of axonal excitability and provides indirect information about the functionality of sodium ion channels.
Brief Pain Inventory	Two days	This questionnaire assesses pain severity, location of pain, and impact on daily functions in the past 24 hours. Pain severity is scored on a numeric scale from zero to ten, with zero being no pain and ten being the worst possible pain.
Serum cytokine concentrations	Two days	Interleukin-6, interleukin-8, interleukin-1ß and tumor necrosis factor alpha in pg/ml.
Short Form 12 (SF-12)	Two days	This questionnaire assesses the quality of life using 12 items. Each item is scaled on a range between zero and a maximum of six. Weighted sums are calculated and transformed into a population-standardized score ranging between zero and 100. The higher the score, the better is the respective life quality compared to the average population.

Trial Locations

Locations (1)

University Medical Center; 🇩🇪 Göttingen, Germany