Clinical, neurophysiological, and radiological characteristics of peripheral neuropathy in patients with rheumatoid arthritis: A cross-sectional observational study.

Neural involvement contributes to body dysfunction and compromised life quality in patients with rheumatoid arthritis (RA). We aimed to investigate the incidence, pattern, associations, predictors and best diagnostic tools of peripheral neuropathy (PN) in RA patients. We recruited 586 RA patients. Patients were categorized into three groups based on the presence (either clinically or subclinical) or absence of PN. PN was found electro-physiologically in 396 patients, 348 with clinical evidence of PN and 48 without clinical evidence. There were significant correlations between PN development and age, disease duration, involved joints, subcutaneous nodule, and VAS score. The mean cross-sectional areas were 9.55 ± 2.35, 9.62 ± 2.28, 9.19 ± 2.51 and 9.16 ± 2.43 mm2 in the right and left median and ulnar nerves, respectively. The number of affected small joints was an independent predictive factor of polyneuropathy and multiple mononeuropathy with an adjusted OR of 1.62 and 1.352, respectively. PN is highly prevalent in patients with RA, including those without overt symptoms or signs. It is highly associated with disease severity, disease duration, age, joint affection and erosion, VAS score and HAQD1. All types of PN could occur in RA. The US could be used for the diagnosis of PN in RA patients. The ultrasonographic references for the examined nerves were provided.