Home-based Respiratory-gated Transcutaneous Auricular Vagus Nerve Stimulation for Rheumatoid Arthritis—A Feasibility Study

Abstract

Introduction/objectives: Rheumatoid arthritis is a chronic autoimmune disease that primarily affects the joints, causing pain, inflammation, and long-term joint damage. Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising non-pharmacological intervention for managing pain and inflammation, particularly when delivered in the exhalation phase of respiration. However, until now, the lack of portable equipment has meant the respiratory phase effects have not been evaluated outside of the laboratory or in a home setting. The primary goal of this study was to determine the feasibility of a future clinical trial of home-based respiratory-gated taVNS in people with rheumatoid arthritis.

Methods: This was a single-arm, non-randomised feasibility trial involving 12 individuals with active rheumatoid arthritis. Participation involved 12 respiratory-gated taVNS sessions at home and three laboratory visits for outcome assessments (day 1, day 8, and day 15). Feasibility outcomes focused on recruitment rate, intervention adherence, acceptability questionnaires, and adverse events. In addition, outcome measures related to pain, psychological distress, and key inflammatory biomarkers were assessed.

Results: Feasibility outcomes demonstrated an acceptable recruitment rate, high adherence (90% session completion), excellent usability (9/10), and acceptability (average score 66%, general score 87%), with no severe treatment-emergent adverse events. While single-armed and not powered to determine efficacy, medium to large pre- to post-intervention reductions in pain interference, grip pain intensity, psychological distress, and tumour necrosis factor-alpha levels were observed, with minimal changes in other outcomes.

Conclusion: An adequately powered, randomised controlled trial of home-based respiratory-gated taVNS in people with rheumatoid arthritis is feasible and safe.

Key Points: To the best of our knowledge, this study is the first to evaluate the feasibility of homebased respiratory-gated (RG) transcutaneous auricular vagus nerve stimulation (taVNS) for the treatment of rheumatoid arthritis (RA). Feasibility outcomes demonstrated high adherence and excellent usability ratings with few treatment-emergent adverse events reported. Home-based RG taVNS using the developed system is safe and feasible to evaluate in an adequately powered, controlled trial.