NCT07173400

Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Symptom Severity, Sleep Quality, Central Sensitization, and Kinesiophobia in Fibromyalgia

Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Symptom Severity, Sleep Quality, Central Sensitization, and Kinesiophobia in Fibromyalgia: A Randomized Controlled Trial

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (actual)
• Sponsor: Hatice Betigul Meral · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

Fibromyalgia is a chronic condition characterized by widespread musculoskeletal pain, fatigue, sleep disturbances, and sensitivity to touch. Current treatments often provide only partial relief. This study evaluates a non-invasive technique called transcutaneous auricular vagus nerve stimulation (TaVNS), which delivers gentle electrical impulses to a part of the ear connected to the vagus nerve. The vagus nerve plays an important role in regulating pain, stress, and autonomic body functions such as sleep. In this randomized controlled pilot trial, participants with fibromyalgia are assigned to receive either active TaVNS or sham (placebo) stimulation for 30 minutes per day, five days per week, over a four-week period. Participants are followed for a total of 8 weeks. The investigators will assess outcomes including pain intensity, sleep quality, central sensitization, and fear of movement (kinesiophobia).

Detailed description

Fibromyalgia (FM) is a chronic pain syndrome associated with widespread musculoskeletal pain, fatigue, sleep disturbances, and autonomic dysregulation. Current treatments provide only partial relief, highlighting the need for novel therapeutic approaches. Rationale: The vagus nerve is a key regulator of autonomic and inflammatory processes. Transcutaneous auricular vagus nerve stimulation (TaVNS) is a non-invasive technique that can modulate vagal activity through electrodes placed on the external ear, offering a potential alternative to surgically implanted vagus nerve stimulators. Study Design: This is a randomized, sham-controlled pilot trial conducted at Istanbul Medipol University. Thirty participants with fibromyalgia are randomized in a 1:1 ratio to receive either active TaVNS or sham stimulation. Intervention: Device: VagusStim® (Vagus Medical Technologies, Istanbul, Türkiye; CE-marked). Electrode placement: left cymba concha (active group) vs. left earlobe (sham group). Stimulation parameters: frequency 1-30 Hz, pulse width 50-250 μs, current intensity individually adjusted (0.1-36 mA) to each participant's sensory threshold. Schedule: 30 minutes per day, 5 days per week, for 4 consecutive weeks (20 sessions total). Supervision: All sessions are clinician-supervised. Outcome Measures: Primary outcomes: Pittsburgh Sleep Quality Index (PSQI) - subjective sleep quality. Fibromyalgia Impact Questionnaire (FIQ) - disease severity and functional impact. Central Sensitization Inventory (CSI) - symptoms related to central sensitization. Secondary outcomes: Visual Analog Scale (VAS) - pain intensity. Tampa Scale for Kinesiophobia (TSK) - fear of movement. Symptom Severity Scale (SSS). Widespread Pain Index (WPI). Assessment timepoints: baseline, week 2, week 4, and week 8.

Conditions

• Fibromyalgia (FM)
• Chronic Pain

Interventions

Type	Name	Description
DEVICE	Active Transcutaneous Auricular Vagus Nerve Stimulation (TaVNS)	Active TaVNS delivered with the VagusStim® device (Vagus Medical Technologies, Istanbul, Türkiye). The bipolar electrode was placed on the left cymba concha. Stimulation was applied for 30 minutes per day, 5 days per week, for 4 weeks (20 sessions). Parameters included frequency 1-30 Hz, pulse width 50-250 μs, and current intensity individually adjusted (0.1-36 mA) to the participant's sensory threshold.
DEVICE	Sham Transcutaneous Auricular Vagus Nerve Stimulation	Sham stimulation delivered with the same VagusStim® device under identical conditions. The electrode was rotated and placed on the left earlobe, which lacks vagal innervation. Sessions lasted 30 minutes per day, 5 days per week, for 4 weeks (20 sessions). No effective vagus nerve stimulation was delivered, preserving participant blinding.

Timeline

• Start date: 2025-08-01
• Primary completion: 2025-10-10
• Completion: 2025-10-10
• First posted: 2025-09-15
• Last updated: 2026-01-15

Locations

1 site across 1 country: Turkey (Türkiye)