Multisite Transcutaneous Electrical Nerve Stimulation in Fibromyalgia: A Randomized, Double-Blind, Sham-Controlled Crossover Trial Comparing Two Stimulation Modalities
Fibromyalgia is a chronic and multifactorial disorder characterized by widespread musculoskeletal pain, heightened pain sensitivity, fatigue, sleep disturbances, cognitive complaints, and affective symptoms such as anxiety and depression. Despite the availability of pharmacological and non-pharmacological interventions, symptom control often remains suboptimal, and currently available treatments may be associated with limited efficacy or poor tolerability. Consequently, there is a growing need for effective, safe, and personalized non-pharmacological therapeutic approaches. In a previous randomized controlled trial (EXOFIB), we investigated the effects of the Exopulse Mollii Suit, a non-invasive neuromodulation device delivering multisite transcutaneous electrical nerve stimulation (TENS), in patients with fibromyalgia. Using stimulation parameters consisting of a frequency of 20 Hz, a voltage of 20 V, and a pulse width of 55-85 µs, active stimulation was associated with clinically meaningful improvements in pain, fatigue, and quality of life compared with sham stimulation. These findings provided evidence supporting the therapeutic potential of the Exopulse Mollii Suit in the management of fibromyalgia-related symptoms. However, while EXOFIB established the efficacy of active stimulation relative to sham stimulation, it did not address whether alternative stimulation parameter configurations could yield superior clinical outcomes. To date, no randomized crossover study has directly compared different active stimulation settings of the Exopulse Mollii Suit in patients with fibromyalgia. Consequently, the optimal stimulation parameters for maximizing therapeutic benefit in this population remain unknown. The present study has therefore been designed to compare the effects of three stimulation modalities delivered by the Exopulse Mollii Suit, including two active stimulation configurations and one sham stimulation condition. The primary objective is to evaluate and compare their effects on functional disability associated with fibromyalgia, assessed using the Fibromyalgia Impact Questionnaire (FIQ). The inclusion of a sham condition allows assessment of non-specific effects while preserving participant blinding. The stimulation conditions evaluated in this study are: * Condition A (active stimulation): frequency 20 Hz, voltage 20 V, pulse width 55-85 µs; * Condition B (active stimulation): frequency 20 Hz, voltage 20 V, pulse width 100-125 µs; * Condition C (sham stimulation): brief initial active stimulation followed by discontinuation of stimulation after one minute, while maintaining identical device settings, session duration, and study procedures in order to preserve participant blinding. By identifying the most effective stimulation setting, this study aims to optimize the clinical use of the Exopulse Mollii Suit in fibromyalgia and to contribute to the development of more individualized neuromodulation strategies. Ultimately, the findings may improve symptom management, reduce functional disability, and enhance quality of life in patients living with fibromyalgia.
Patients aged between 18 and 75 years, [+2]
Patient included in another research protocol during the study period; [+8]