Background:

Bechterew disease (ankylosing spondylitis) is a chronic inflammatory rheumatic condition affecting the axial skeleton, commonly causing persistent back pain, morning stiffness, and reduced mobility. Pharmacological therapies (e.g., NSAIDs, DMARDs) may be limited by side effects or insufficient symptom control. Non-invasive vagus nerve stimulation (nVNS) has been proposed as a potential adjunct approach for pain and inflammation modulation, as the vagus nerve is involved in autonomic regulation and inflammatory signaling.

Methods:

Study design: Single-center, prospective, open-label pilot study.

Participants: 7 patients diagnosed with Bechterew disease, aged 18–65 years. Inclusion criteria included confirmed diagnosis, persistent pain despite conventional pharmacological treatment, and ability to provide informed consent.

Intervention: Participants used the Pulsetto nVNS device twice daily with 20-minute pain management sessions (morning and evening). If no improvement was observed after the morning session, patients were advised to repeat stimulation after 1 hour for another 20 minutes.

Assessments: Participants completed a daily quiz assessing morning spinal stiffness (yes/no), joint pain before and after stimulation (1–10 scale), spinal range of motion (increased/decreased), mood/well-being, sleep quality, immediate subjective effects, concentration/task completion, and nighttime sleep difficulty.

Data analysis: Descriptive statistics (frequencies, percentages, means, SD). Paired t-tests compared pre- vs post-stimulation pain intensity.

Results:

Morning stiffness: Decreased in 82.05% of observations (n = 64) and unchanged in 17.95% (n = 14).  Joint pain (before stimulation): Mean 4.18 (SD = 1.87).  Joint pain (after stimulation): Mean 2.10 (SD = 1.29).  Pain reduction: Significant reduction in pain intensity following nVNS (t(77) = 12.64, p < 0.001). Spinal range of motion: Increased in 71.79% (n = 56), decreased in 2.56% (n = 2), unchanged in 25.65% (n = 20). Well-being/mood: Improved in 51.3% (n = 40), neutral in 46.2% (n = 36), worsened in 2.6% (n = 2). Sleep quality: Improved in 43.6% (n = 34), neutral in 51.3% (n = 40), worsened in 5.1% (n = 4). Immediate subjective response: Most reported feeling relaxed, calm, or energised; a smaller proportion reported mild discomfort or dizziness that subsided shortly after the session. Concentration/task completion: Improved in 63.5% (n = 49), unchanged in 30.8% (n = 24), worsened in 5.7% (n = 5). Nighttime sleep: No trouble sleeping in 87% (n = 68); difficulty falling asleep in 11.5% (n = 9); frequent awakenings/poor sleep quality in 1.5% (n = 1).

Conclusion:

In this small, open-label pilot study of Bechterew disease patients, nVNS with Pulsetto was associated with a significant reduction in self-reported joint pain and high proportions of observations reporting improvements in morning spinal stiffness, spinal range of motion, mood, sleep quality, and concentration. Key limitations include the absence of a control group, reliance on self-reported outcomes, small sample size, and short study duration (two weeks). Larger randomized controlled trials with longer follow-up and optimized stimulation parameters are needed to confirm effectiveness and characterize safety and durability of effects.

Author:

Dr. Vaidas Dirse

Hematology, Oncology and Transfusion Medicine Center,

Vilnius University Hospital Santaros Klinikos.