Vagus Nerve Stimulation for Chronic Widespread Pain
This study is looking at how stimulating a nerve called the vagus nerve might help adults with chronic widespread pain or fibromyalgia. Researchers want to see if two different ways of stimulating this nerve—either through deep breathing exercises (deep exhalation) or with a small electrical device placed on the ear (ear electrical stimulation)—can reduce pain intensity, muscle stiffness, and improve overall well-being. The study aims to find out if vagus nerve stimulation helps with pain and which method might be more effective. You could be eligible if you are an adult aged 18 or older with a diagnosis of chronic widespread pain or fibromyalgia, but not if you have certain heart or nerve conditions.
- Study design
- This is a randomized controlled study planning to enroll 100 participants. It will compare two types of vagus nerve stimulation with a group that receives no immediate treatment.
- What's involved
- Participants will either perform deep exhalation exercises, use an ear electrical stimulator, or be in a group that receives no treatment for two weeks. Pain intensity will be measured at two weeks, and muscle stiffness at eight weeks.
- Compensation
- Not stated in the trial record.
- Follow-up
- Pain intensity is measured from enrollment to the end of treatment at 2 weeks, and muscle stiffness is measured from enrollment to the end of treatment at 8 weeks.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
The Effect of Vagus Nerve Stimulation on Pain and Functional Activities in Individuals With Chronic Widespread Pain
At a glance
Conditions
Where it's being run
1 sites across 1 statesWho to contact
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What this trial measures
- Pain IntensityFrom enrollment to the end of treatment at 2 weeks
Pain intensity will be assessed using the Visual Analog Scale (VAS), a 10 cm horizontal line anchored by "no pain" and "worst imaginable pain." Participants mark their current level of pain on the line, which is measured in centimeters (cm).
- Muscle stiffnessFrome enrollment to the end of treatment at 8 weeks
Muscle stiffness, defined as the resistance of the tissue to an external force, will be measured in the upper trapezius using the MyotonPro device. Stiffness reflects the biomechanical integrity of muscle tissue. Unit of Measure: Newtons per meter (N/m)
- Pressure Pain Threshold - Trapezius muscleFrom enrollment to the end of treatment period at 2 weeks
Pressure pain threshold (PPT) at the mid-belly of the upper trapezius will be assessed using a calibrated analog pressure algometer. PPT is defined as the minimum force required to elicit pain and reflects mechanical pain sensitivity. Unit of Measure: Kilograms per square centimeter (kg/cm²).
- SDNN (Standard Deviation of NN intervals)From enrollment to the end of treatment at 2 weeks
SDNN will be used to assess overall heart rate variability, reflecting both sympathetic and parasympathetic nervous system activity over a 10-minute resting period. Unit of Measure: milliseconds (ms).
- Mechanical Stress Relaxation TimeFrom enrollment to the end of treatment at 8 weeks
Mechanical Stress Relaxation Time, defined as the time required for tissue to return to its original state following a mechanical impulse, will be measured using the MyotonPro device. This parameter reflects the viscoelastic properties of skeletal muscle. Unit of Measure: milliseconds (ms).
- Muscle Oscillation FrequencyFrom enrollment to the end of treatment at 8 weeks.
Frequency, representing the natural oscillation frequency of muscle tissue in response to a brief mechanical impulse, will be measured using the MyotonPro device. It reflects the intrinsic muscle tone and biomechanical behavior of the tissue. Unit of Measure: Hertz (Hz).
- Pressure Pain Threshold - Lumbar Paraspinal MusclesFrom enrollment to the end of treatment at 8 weeks
PPT at the lumbar paraspinal region (L5 level) will be measured using an analog pressure algometer to assess localized pain sensitivity. Unit of measurement: Kilograms per square centimeter (kg/cm²)
- Pressure Pain Threshold - Calf MusclesFrom enrollment to the end of treatment at 8 weeks
PPT at the junction of the gastrocnemius and soleus muscles in the calf will be measured using a pressure algometer to evaluate distal pain sensitivity. Unit of Measure: Kilograms per square centimeter (kg/cm²)
- Muscle Elasticity (Logarithmic Decrement)From enrollment to the end of treatment at 8 weeks
Elasticity, measured as logarithmic decrement, describes the ability of muscle tissue to return to its original shape after deformation. It will be measured using the MyotonPro on the upper trapezius. Lower values indicate greater elasticity. Unit of Measure: Unitless (logarithmic decrement)
- RMSSD (Root Mean Square of Successive Differences)Baseline, after 2 weeks and after 8 weeks
RMSSD will be used as a marker of short-term parasympathetic activity. Unit of Measure: milliseconds (ms).
- SDANN (Standard Deviation of Average NN intervals)Baseline, after 2 weeks, and after 8 weeks
SDANN will be used to evaluate longer-term components of heart rate variability associated with sympathetic activity. Unit of Measure: milliseconds (ms)
- LF Power (Low Frequency Power)Baseline, after 2 weeks and after 8 weeks
LF Power will be analyzed to assess contributions from both sympathetic and parasympathetic nervous systems in frequency domain. Unit of Measure: milliseconds² (ms²).
- HF Power (High Frequency Power)Baseline, after 2 weeks and after 8 weeks
HF Power will be measured to evaluate parasympathetic (vagal) nervous system activity. Unit of Measure: milliseconds² (ms²).
- LF/HF RatioBaseline, after 2 weeks and after 8 weeks
LF/HF ratio will be used as a marker of autonomic balance, indicating the relative influence of sympathetic to parasympathetic tone. Unit of Measure: Ratio (unitless).
- VLF Power (Very Low Frequency Power)Baseline, after 2 weeks and after 8 weeks
VLF Power will be measured to assess longer-term regulatory systems, including thermoregulation and hormonal factors. Unit of Measure: milliseconds² (ms²).
- ULF Power (Ultra Low Frequency Power)Baseline, after 2 weeks and after 8 weeks
ULF Power will be assessed to capture circadian and ultradian influences on autonomic regulation. Unit of Measure: milliseconds² (ms²).