The primary objective of the study is to study the change in SpA disease activity, according to ASAS20 definition (Anderson et al., 2001), after 8 weeks of VNS treatment versus placebo non-specific stimulation (control group).
The secondary objectives of the Clinical Investigation are to show differences in disease evolution between the active and placebo periods of 8 weeks treatment with active VNS versus placebo VNS of the following items:
1. Change in disease activity according to "ASAS40" criteria 2. Obtaining a partial remission according to the ASAS definition 3. Change in BASFI 4. Change in C-reactive protein (CRP)serum level and erythrocytes sedimentation rate (ESR), 5. Change in ASDAS\_CRP and ASDAS\_ESR 6. Difference in levels of circulating cytokines, IL-6, IL-23, IL-17, IL-33 and of matrix metallopeptidases (MMP3-8-9). 7. Change in quality of life : assessment according to the following indexes: SF-36, AS Quality of Life (ASQOL) 8. Change in Health Index of patient with SpA (ASAS HI) and of the Productivity at Work Index (WPI) 9. Change in fatigue (BASDAI 1st question) and global pain 10. Change in Anxiety and Depression Assessment (HAD) 11. Change in BASMI 12. Change in non-steroidal anti-inflammatory drugs (NSAID) intake score.
Patient from 18 to 90 years with axial SpA, meeting the ASAS classification criteria, followed for at least one year, with presence of radiological sacro-illitis (ankylosing spondylitis) or not;
Patient suffering active SpA, with or without treatment, having a total BASDAI score ≥ 4 (0-10) at baseline and a score of global pain ≥ 4 (0-10);
SpA insufficiently relieved despite optimal drug management for at least 6 months including at least 2 different NSAIDs at the maximum tolerated dose for at least 3 months (or less in case of intolerance) and at least two lines of biotherapies or discontinued SpA treatments due to intolerance, contraindication.
Patient under guardianship;
Cardiac arrhythmia;
Patients with cochlear implant;
Patients with known heart disease;