Central sensitisation features are associated with neuropathic pain-like symptoms in patients with longstanding rheumatoid arthritis: a cross-sectional study using the central sensitisation inventory.

Objectives: Several studies have indicated that arthralgia may be driven by central sensitisation. Central sensitivity syndrome (CSS) is a concept that unifies various symptoms due to central sensitisation. Recently, the central sensitisation inventory (CSI) was developed as a screening questionnaire to detect CSS. Using the CSI, we examined the prevalence, the clinical characteristics of CSS, and the association between CSS and neuropathic pain (NP)-like symptoms among rheumatoid arthritis (RA) patients.

Methods: The CSI was administered to 240 RA outpatients. We evaluated their disease activity and several potentially relevant patient-reported outcomes. We compared the clinical parameters depending on the severity of CSS and examined the effect of the CSI score on NP-like symptoms among the relevant clinical parameters using multivariate analyses.

Results: The mean disease duration was 9.58 ± 7.76 years. Eighteen (7.5 %) patients had CSS, which was associated with evaluator global assessment (EGA) (odds ratio (OR) 0.860); fibromyalgia symptom scale (OR 1.46); painDETECT questionnaire score (OR 1.24); hospital anxiety and depression scale-anxiety (OR 1.35); and physical (OR 0.898), mental (OR 0.828), and role-social (OR 0.946) component summary scores on the Short-Form 36-Item Health Survey. CSI score was the factor that contributed most to NP-like symptoms (p=0.000, β=0.266).

Conclusions: NP-like symptoms might be one of the symptoms of CSS in longstanding RA patients. In longstanding RA patients who have disproportionately greater NP-like symptoms and/or widespread pain compared with degree of inflammation, detecting CSS using CSI might help to understand the pathogenesis of patients.