The Effects of Vagus Nerve Stimulation on Pain, Muscle Stiffness, Heart Rate, And Functional Activities in Individuals With Chronic Widespread Pain - A Double Blinded Randomized Control Trial
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 入组人数
- 100
- 试验地点
- 2
- 主要终点
- Pain Intensity
研究概览
简要总结
The goal of this clinical trial is to examine the effect of vagus nerve stimulation (VNS) on chronic, widespread pain in adults. The study will also evaluate which method of VNS-electrical ear stimulation or deep exhalation breathing-has a more significant impact on pain intensity, quality of life, and emotional well-being.
The main questions it aims to answer are:
Does vagus nerve stimulation reduce pain intensity in individuals with chronic, widespread pain?
Which intervention-electrical ear stimulation or deep exhalation breathing-provides a greater improvement in autonomic function, emotional status, and quality of life?
Researchers will compare two active interventions-electrical ear stimulation and deep exhalation breathing-to a no-treatment control group to determine relative effectiveness on pain and related outcomes.
Participants will:
Be randomly assigned to one of three groups:
- Electrical Ear Stimulation: Apply a small, non-invasive device to the ear for 20 minutes, twice daily for two weeks.
- Deep Exhalation Breathing: Perform balloon-blowing exercises (four deep exhalations per set) once every waking hour each day for two weeks.
- Control Group: Receive no intervention during the two-week period. These participants will complete baseline testing, return after two weeks for follow-up testing, and then be debriefed. They will have the option to withdraw or receive an active treatment after study data collection concludes.
Complete four questionnaires to assess pain, emotional state, and quality of life.
Undergo physiological assessments including heart rate variability, neck muscle tissue flexibility (via MyotonPro), and pressure pain sensitivity (via pressure algometer), both before and after the 2-week period.
Participation includes two in-person sessions (approximately 1 hour each) and daily home practice (for intervention groups) lasting 40-60 minutes per day for two weeks. The study involves minimal risk, and no compensation is provided. Participation is voluntary, and confidentiality will be strictly maintained.
详细描述
Detailed Description:
Study Overview:
This randomized controlled clinical trial investigates the effects of two forms of non-invasive vagus nerve stimulation (VNS) on chronic widespread pain (CWP). The study is designed to explore whether stimulating the vagus nerve through auricular electrical stimulation (AES) or deep forced exhalation (DFE) improves pain, muscle stiffness, and functional status in individuals with CWP.
Vagal nerve stimulation (VNS) has been associated with modulation of the autonomic nervous system, leading to downstream effects on inflammation, pain perception, and emotional regulation. This study compares the effectiveness of these two intervention methods with a control group that receives no treatment during the study period.
Research Questions:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Participant, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults 18 years of age or older
- •Diagnosed by a healthcare provider with chronic widespread pain or fibromyalgia
排除标准
- •Cardiovascular disorders: Such as arrhythmia (irregular heartbeat), heart failure, coronary artery disease, or history of heart surgery
- •Neurological disorders: Including epilepsy, Parkinson's disease, multiple sclerosis, neuropathy, or seizures
- •Endocrine disorders: Such as uncontrolled diabetes, thyroid disease (hypothyroidism or hyperthyroidism), or adrenal disorders
- •Gastrointestinal disorders: Including inflammatory bowel disease (Crohn's disease, ulcerative colitis), irritable bowel syndrome, or chronic acid reflux (GERD)
- •Respiratory disorders: Such as asthma, chronic bronchitis, emphysema, or sleep apnea
- •Vestibular disorders: Including Meniere's disease, benign paroxysmal positional vertigo (BPPV), or any condition causing balance problems
- •History of concussion or traumatic brain injury
- •Frequent dizziness or vertigo: History of unexplained or recurring episodes
- •Chronic or recurrent headaches: Including migraines, tension-type headaches, or cluster headaches
- •Ear problems: History of ear infections, hearing loss, tinnitus (ringing in the ears), or ear surgeries
- •Throat problems: History of chronic sore throat, difficulty swallowing (dysphagia), or throat surgery
- •Herniation: History of any type of herniation such as spinal disc herniation, inguinal (groin) hernia, or abdominal hernia
- •Skin sensitivity to electrical stimulation: Known allergic reaction, rash, or irritation from electrode pads or electrical devices applied to the skin
结局指标
主要结局
Pain Intensity
时间窗: From 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 stiffness
时间窗: Frome 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 muscle
时间窗: From 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)
时间窗: 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 Time
时间窗: From 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 Frequency
时间窗: From 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 Muscles
时间窗: From 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 Muscles
时间窗: From 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)
时间窗: 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)
SDANN (Standard Deviation of Average NN intervals)
时间窗: 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)
时间窗: 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)
时间窗: 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 Ratio
时间窗: Baseline, 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)
时间窗: 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)
时间窗: 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).
Pain Intensity
时间窗: From 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 stiffness
时间窗: Frome 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 muscle
时间窗: From 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)
时间窗: 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 Time
时间窗: From 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 Frequency
时间窗: From 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 Muscles
时间窗: From 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 Muscles
时间窗: From 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)
时间窗: 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)
时间窗: 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)
时间窗: 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)
时间窗: 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)
时间窗: 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 Ratio
时间窗: Baseline, 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)
时间窗: 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)
时间窗: 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).
次要结局
- Quality of Life (Quality of Life Scale - QOLS)(From enrollment to the end of treatment period at 2 weeks.)
- Positive Affect Score (PANAS)(From enrollment to the end of treatment period at 2 weeks)
- Quality of Life (Quality of Life Scale - QOLS)(From enrollment to the end of treatment period at 2 weeks.)
- Positive Affect Score (PANAS)(From enrollment to the end of treatment period at 2 weeks)
- Depression Severity (Patient Health Questionnaire-9)(From enrollment to the of treatment period at 2 weeks)
- Negative Affect Score (Positive and Negative Affect Schedule - PANAS)(From enrollment to the end of treatment at 8 weeks)
- Muscle Creep/Compliance(From enrollment to the end of treatment at 8 weeks)
研究者
Mohammad(Reza) Nourbakhsh
Professor of Physical Therapy
University of North Georgia