Ultrasonographic measurement of the peroneal and tibial nerves in patients with rheumatoid arthritis with symptoms or signs of polyneuropathy: A cross-sectional study

Abstract

Background: Drug toxicity, vasculitis, entrapment neuropathy, and amyloidosis are among the various different reasons of peripheral neuropathy in rheumatoid arthritis (RA). We aimed to determine the cross-sectional areas (CSA) of the peroneal and tibial nerves in patients with RA who had neuropathic symptoms, and to determine a cutoff value for peroneal and tibial nerves CSA by ultrasonography (USG) to diagnose polyneuropathy (PN) in patients with RA. Materials and Methods: Sixty-nine patients with RA and thirty healthy controls were included in this cross-sectional study. According to nerve conduction study (NCS) test, patients with RA were divided into two groups, diagnosed as having PN or not. Demographic data, laboratory findings, CSA of bilateral peroneal and tibial nerves, NCS values, and painDETECT (PD-Q) scores of all patients were assessed. Disease duration, disease activity score 28, duration of neuropathic symptoms, and Health Assessment Questionnaire of patients with RA were also determined. Results: No statistically significant difference was found among the groups in terms of age, gender, and laboratory findings. However, a statistically significant difference was found among these three groups in comparison with PD-Q, NCS values, and nerve CSA (P < 0.05). Seropositivity was statistically higher in the group with PN. When peroneal nerve CSA cutoff value was taken as 20 mm2, sensitivity and specificity values were 96.6% and 79.6%, respectively, for the diagnosis of PN (area under the curve [AUC] = 0.962). When tibial nerve CSA cutoff value was taken as 8.5 mm2, the sensitivity and specificity values were 93.1% and 71.6%, respectively, for the diagnosis of PN (AUC = 0.897). Conclusion: USG can be used as a noninvasive diagnostic modality in the assessment of RA-associated PN. © 2020 Indian Journal of Rheumatology Published by Wolters Kluwer - Medknow.