Transcutaneous auricular vagus nerve stimulation of limited benefit in erosive osteoarthritis
- 17-12-2025
- Osteoarthrosis
- Editor's Choice
- News
medwireNews: Transcutaneous auricular vagus nerve stimulation (taVNS) does not significantly improve hand pain relative to sham stimulation in people with erosive hand osteoarthritis but is well tolerated and may benefit patients with at least two inflamed synovial joints, research suggests.
The multicenter, randomized controlled ESTIVAL trial also found that “taVNS was associated with improved function and patient global assessment score,” report Jérémie Sellam (Saint-Antoine Hospital, Paris, France) and co-authors in The Lancet Rheumatology.
In all, 142 adults (mean age 67 years, 88% women) with hand osteoarthritis with at least one erosive interphalangeal joint and ultrasound-confirmed synovitis were randomly assigned to receive 20 minutes of taVNS (VAGUSTIM; Schwa Medico, Rouffach, France; n=73) or sham stimulation with no electrical current (n=69) every day for 12 weeks.
At baseline, participants in the taVNS group reported a median hand pain score of 63 mm, measured on a visual analog scale (VAS) of 0–100 mm, while those in the sham group had a median score of 60 mm.
At week 12, VAS hand pain had reduced by a median of 16 mm in the taVNS group compared with a median of 6 mm reduction in the sham group. The between-group difference of 10 mm was not statistically significant, and the primary study endpoint was not met, the researchers note.
Between baseline and 12 weeks, there were also no significant differences between taVNS and sham stimulation in changes in Australian–Canadian Osteoarthritis pain, function, and stiffness scales, Cochin hand functional disability scale score, quality of life (EQ-D5), Hospital Anxiety and Depression scale score, fatigue intensity, number of painful and swollen hand joints, or inflammatory biomarkers.
There was, however, a significant improvement in the modified Functional Index for Hand Osteoarthritis scale with taVNS versus sham treatment. At week 12, the score had fallen by 4.9 points in the taVNS group whereas it increased by 2.4 points in the sham group.
In addition, mean patient global assessment score improved by 6.9 points among patients in the taVNS group but fell by 3.8 points among those in the sham group, a significant difference.
Reduced pain in people with greater joint inflammation
An exploratory subgroup analysis among patients with at least two joints with ultrasound synovitis showed that those given taVNS (n=58) had a significantly greater reduction in the median VAS pain score than those given sham treatment (n=56), at 22.5 mm versus 6.5 mm.
In patients with at least five joints with ultrasound synovitis the reduction in median VAS pain score was 28 mm with taVNS (n=35) compared with 9 mm with sham stimulation (n=36), also a significant difference.
No new safety signals
The researchers note that there were “no emerging safety concerns,” and no serious adverse events (AEs) occurred in either group. Non-serious AEs, including skin irritation, mild pain, and ear tingling, occurred in 30% of participants in the taVNS group and 23% of those in the sham group.
Sellam et al conclude: “Although the primary endpoint was not met, the consistent pain reduction observed in patients with greater synovial inflammation suggests that taVNS merits further investigation in this erosive hand osteoarthritis population.”
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