Résumé
Background: well known for its effects on vegetative functions, the vagus nerve also plays a role in controlling and reducing the pain signal. The aim of this open-label pilot study is to determine the efficacy of transcutaneous vagal stimulation (tVNS) in chronic low back pain. Methods: chronic low back pain patients with VAS≥40/100 mm were recruited in the the Physical Medicine and Rehabilitation Department of Montpellier University Hospital. The tVNS was performed for 3 months, using an upstream VAGUSTIM device connected to an auricular electrode placed 30 minutes a day on the left ear. Clinical efficacy was evaluated by changes between baseline and at 4 weeks with low back pain VAS. Results: thirty patients (mean age 47.8, 60% women) were included from February to December 2023. After 1 month of use, we observed a statistically significant reduction in the pain VAS, mean decrease of 16.1 mm [-9; -23.1] (p<.0001). This effect continued for up to three months of daily use of the tVNS device, mean decrease of 22.9 mm [-12.5; -33.3] (p=0.0001). We also noted a significant reduction in patients' assessment of functional disability and perceived catastrophizing, anxiety and depression, and an improvement in quality of life, with an increasing effect over time. No serious adverse events were reported. Conclusion: this first proof-of-concept trial indicated that tVNS could reduce pain in chronic low back pain, making it possible to carry out a prospective blind study with a control group.