How do central sensitisation features affect symptoms among patients with rheumatoid arthritis? Analysis of pain descriptors and the effect of central sensitivity syndrome on patient and evaluator global assessments.

OBJECTIVES: Central sensitivity syndrome (CSS) comprises various symptoms caused by central sensitisation (CS). Using the central sensitisation inventory (CSI), a screening questionnaire developed for detecting CSS, this syndrome was recently identified in patients with long-standing rheumatoid arthritis (RA). However, the descriptors of CS-related pain and the effects of CSS on symptoms in patients with rheumatoid arthritis (RA) remain unknown. We examined the characteristics of pain and influence of CSS on patient and evaluator global assessment among multiple clinical variables. METHODS: We used the central sensitisation inventory (CSI) and short-form McGill pain questionnaire to evaluate CSS and characteristics of pain in 240 outpatients with RA. Disease activity, fibromyalgia, neuropathic pain, anxiety, depression, pain catastrophising, and health-related quality of life were evaluated. We used multivariate analysis to analyse the characteristics of CS-related pain according to CSI and the effect of CSS on patient global assessment (PGA), evaluator global assessment (EGA), and PGA minus EGA among relevant clinical variables. RESULTS: In patients with RA, the main descriptors of pain according to severity of CSI scores were "sharp" and "stabbing", whereas those of pain according to disease activity were "tender" and "throbbing". CSS was associated with EGA (p=0.000, ß=- 0.199) and PGA minus EGA (p=0.021, ß=0.147), but not with PGA. CONCLUSIONS: In patients with RA, descriptors for CS-related pain differ from those for disease activity-related pain. CSS may have an important impact on EGA and PGA minus EGA. Additionally, CSI may be helpful in identifying why there is discordance between PGA and EGA.

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, ß=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.

How do neuropathic pain-like symptoms affect health-related quality of life among patients with rheumatoid arthritis?: A comparison of multiple pain-related parameters.

Objectives: Rheumatoid arthritis (RA) pain is thought to be nociceptive. However, recent studies indicate that RA also involves the neuropathic pain (NP) mechanism. We examined pain features and the effect of NP-like symptoms on health-related quality of life (HRQOL) among patients with RA.Methods: The painDETECT questionnaire (PDQ) was used to evaluate NP-like symptoms among 145 outpatients with RA. Disease activity, pain quality, and HRQOL were evaluated. We compared clinical parameters between patients with and without NP-like symptoms and analyzed pain features and the effect of NP-like symptoms on HRQOL, along with multiple other pain-related parameters.Results: Thirty (20.7%) patients had NP-like symptoms (PDQ ≥13). Patient global assessment and evaluator global assessment diverged for patients with RA who had NP-like symptoms. Of the examined pain-related parameters, PDQ score (p = .038, ß = -.173) was associated with the Short-Form 36-Item Health Survey role-social component summary score, but not with the physical or mental component summary scores.Conclusion: NP-like symptoms affected HRQOL among patients with RA. There was discordance between global assessments by patients and by evaluators for patients with RA who had NP-like symptoms. Therefore, NP-like symptoms should be given somewhat more attention when treating patients with RA.