Prevalence of various forms of peripheral neuropathy in patients with systemic connective tissue diseases: a clinical and electrophysiological study

Background/Aim. Peripheral neuropathy (PN) in sys-temic connective tissue diseases (SCTDs) represents the apparent disease complications or initial manifestations of clinically undiagnosed conditions. The aim of the study was to identify neuropathies (Ns) and their prevalence, point out the diagnostic significance of some electrophysi-ological (EP) parameters in patients with rheumatoid ar-thritis (RA), systemic lupus erythematosus (SLE), and sys-temic sclerosis (SSc), and establish their association with disease activity (DA) and disease duration (DDu). Meth-ods. A prospective study was conducted at the Rheuma-tology Clinic of the Institute for Treatment and Rehabilita-tion "Niska Banja" over a three-year period. The study in-cluded 157 patients in total, of whom 61 had RA, 40 had SLE, and 56 had SSc. The following parameters were ana-lyzed: age, gender, DDu, course of the disease, and DA index. Moreover, clinical, rheumatological, and neurologi-cal examinations, as well as neurology tests, nerve conduc-tion studies (NCS), and laboratory analyses, were also conducted. Results. In the studied population, we were able to identify various forms of Ns (in 28.7% of patients) by NCS. In all three groups, the most prevalent type of Ns was axonal (23.6%), sensorimotor (18.5%), and polyneu-ropathy (23.6%). There was a significant association be-tween DA and the occurrence of Ns (p < 0.001) in the to-tal population. The most important EP parameter was the sensory nerve action potential amplitude of nervus peroneus superficialis [in 70 (44.6%) patients] and nervus suralis [in 35 (22.3%) patients], and compound muscle action potential amplitude of nervus peroneus [in 32 (20.4%) patients]. DDu in all three groups was longer in the population of patients with Ns. Conclusion. Ns are most common in patients with longer DDu and higher DA. The EP method is im-portant in detecting Ns, especially in the early detection of subclinical forms of Ns and the prevention of disease complications.