Fibromyalgia Syndrome
Conditions
Keywords
Transcutaneous auricular vagus nerve stimulation, taVNS, Heart rate variability, Exercise performance, Autonomic nervous system, Fibromyalgia Syndrome
Brief summary
This randomized controlled trial aimed to compare the effects of unilateral (left-sided) and bilateral transcutaneous auricular vagus nerve stimulation (taVNS) combined with a home exercise program on clinical outcomes, autonomic nervous system function, and exercise performance in individuals with fibromyalgia syndrome (FMS). Participants diagnosed with fibromyalgia were randomly assigned to one of three groups: unilateral taVNS, bilateral taVNS, or a home exercise program. The intervention period lasted two weeks and included ten treatment sessions. Clinical outcomes were assessed using validated scales including the Fibromyalgia Impact Questionnaire (FIQ), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and Pittsburgh Sleep Quality Index (PSQI). Autonomic function was evaluated using heart rate variability (HRV) parameters, and exercise performance was assessed based on repetition capacity. The study aimed to determine whether bilateral stimulation provides additional benefits compared to unilateral stimulation and exercise alone. The findings may contribute to understanding the role of neuromodulation strategies in improving autonomic regulation, symptom severity, and functional performance in individuals with fibromyalgia.
Detailed description
Fibromyalgia syndrome (FMS) is a chronic condition characterized by widespread pain, fatigue, sleep disturbances, and psychological symptoms, often associated with autonomic nervous system dysfunction. Reduced heart rate variability (HRV) and increased sympathetic activity are commonly observed in individuals with FMS, contributing to impaired exercise tolerance and reduced quality of life. Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique that targets the auricular branch of the vagus nerve and has been shown to influence autonomic regulation and central pain processing. However, evidence regarding its effects on exercise performance and the comparative efficacy of unilateral versus bilateral stimulation remains limited. This study was designed as a randomized controlled trial including individuals diagnosed with fibromyalgia. Participants were allocated into three groups: unilateral taVNS, bilateral taVNS, and a home exercise program. The interventions were applied over a two-week period consisting of ten sessions. The taVNS intervention was administered via auricular stimulation targeting vagal afferents, while the exercise group followed a structured home-based program. Outcome measures included clinical symptom scales (FIQ, BAI, BDI, PSQI), autonomic nervous system parameters derived from HRV analysis (including RMSSD, pNN50, LF, HF, and LF/HF ratio), and exercise performance assessed through repetition capacity. Assessments were conducted before and after the intervention period. The primary objective was to compare the effects of unilateral and bilateral taVNS on autonomic function and exercise performance, and to evaluate whether combining neuromodulation with exercise provides additional clinical benefits in individuals with fibromyalgia. The results of this study may help inform rehabilitation strategies integrating neuromodulation and exercise-based interventions.
Interventions
DEVICEtaVNS
Transcutaneous auricular vagus nerve stimulation applied via the auricular branch of the vagus nerve for neuromodulation purposes.
BEHAVIORALHome Exercise Program
A structured home-based exercise program including strengthening and mobility exercises performed over a two-week period.
Sponsors
Istanbul Gelisim University
Bahçeşehir University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Masking description
This study was conducted as an open-label trial; no masking was applied.
Intervention model description
Participants were randomly assigned to one of three parallel groups: unilateral transcutaneous auricular vagus nerve stimulation (taVNS), bilateral taVNS, or a home exercise program. Each participant remained in their assigned group throughout the intervention period, and outcomes were compared between groups.
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
* Were between 18 and 45 years of age * Were diagnosed with fibromyalgia according to the 2016 ACR diagnostic criteria \-- Stable clinical condition * Ability to understand and follow study procedures * Willingness to participate and provide informed consent
Exclusion criteria
* A history of malignancy * Cardiopulmonary diseases contraindicating exercise * Limb loss * Ear infections and implants, implanted electronic devices * Systemic diseases (hematological, endocrine, rheumatological, renal, cardiovascular, gastrointestinal, neurological, or autoimmune diseases) * Active infection * Surgery or major trauma within the previous 6 months * Postmenopausal status * Pregnancy or lactation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Exercise performance (repetition count) | Baseline (Week 0) and Week 2 | Number of repetitions performed during exercise sessions to evaluate functional exercise performance. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fibromyalgia Impact Questionnaire (FIQ) score | Baseline (Week 0) and Week 2 | Change in Fibromyalgia Impact Questionnaire (FIQ) score (range: 0-100; higher scores indicate worse disease severity and functional impairment) to assess disease severity and functional status in patients with fibromyalgia. |
| Beck Anxiety Inventory (BAI) score | Baseline (Week 0) and Week 2 | Change in Beck Anxiety Inventory (BAI) score (range: 0-63; higher scores indicate greater anxiety levels) to assess anxiety severity. |
| Beck Depression Inventory (BDI) score | Baseline (Week 0) and Week 2 | Change in Beck Depression Inventory (BDI) score (range: 0-63; higher scores indicate more severe depressive symptoms) to assess depression severity. |
| Pittsburgh Sleep Quality Index (PSQI) score | Baseline (Week 0) and Week 2 | Change in Pittsburgh Sleep Quality Index (PSQI) score (range: 0-21; higher scores indicate worse sleep quality) to assess sleep quality. |
| Heart Rate Variability (RMSSD) | Week 0 pre-exercise measurement, Week 0 post-exercise measurement, Week 2 pre-exercise measurement, and Week 2 post-exercise measurement | Change in RMSSD (ms), reflecting parasympathetic activity. |
| Heart Rate Variability (pNN50) | Week 0 pre-exercise measurement, Week 0 post-exercise measurement, Week 2 pre-exercise measurement, and Week 2 post-exercise measurement | Change in pNN50 (%), representing parasympathetic modulation. |
| Heart Rate Variability (HF power) | Week 0 pre-exercise measurement, Week 0 post-exercise measurement, Week 2 pre-exercise measurement, and Week 2 post-exercise measurement | Change in high-frequency (HF) power (ms²), reflecting parasympathetic nervous system activity. |
| Heart Rate Variability (LF power) | Week 0 pre-exercise measurement, Week 0 post-exercise measurement, Week 2 pre-exercise measurement, and Week 2 post-exercise measurement | Change in low-frequency (LF) power (ms²), reflecting mixed sympathetic and parasympathetic activity. |
| Heart Rate Variability (LF/HF ratio) | Week 0 pre-exercise measurement, Week 0 post-exercise measurement, Week 2 pre-exercise measurement, and Week 2 post-exercise measurement | Change in LF/HF ratio (unitless), indicating autonomic balance between sympathetic and parasympathetic systems. |
Countries
Turkey (Türkiye)
Contacts
PRINCIPAL_INVESTIGATORKerem KARAGÖZ, PhD
Bahçeşehir University
Outcome results
None listed