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 systemic connective tissue diseases (SCTDs) represents the apparent disease complications or initial manifestations of clinicaly undiagnosed conditions. The aim of our study was to identify neuropathies and their prevalence and point out diagnostic significance of some electrophysiological parameters in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) and to establish their association with disease activity and duration. Methods. A prospective study was conducted at the Rheumatology Clinic of the Institute for Treatment and Rehabilitation ?Niska Banja? over a three-year-period. It included 157 patients in total, distributed as 61 with RA, 40 with SLE, and 56 with SSc. The following parameters were analyzed: age, gender, disease duration, course of disease, disease activity index, clinical rheumatological and neurological examination, neurology tests, nerve conduction study (NCS) and laboratory analyses. Results. In the studied population, we were able to identify various forms of neuropathies (in 28.7% of patients) by nerve conduction study (NCS). In all the three groups the most prevalent type of neuropathy was axonal (23,6%), sensorimotor (18,5%), polyneuropathy (23,6%). There was a significant association between disease activity and the occurrence of neuropathy (p<0.001). The most important electrophysiological parameter was SNAP amplitude n. peroneus superfitialis (70 patients; 51.9%), n. suralis (35 patients; 22.3%) and CMAP amplitude n. peroneus (32 patients; 20.8%). Disease duration in all three groups was greater in the population of patients with neuropathy. Conclusion. Neuropathies are most common in patients with longer disease duration and higher disease activity. The electrophysiological method is important in the detection of neuropathies, especially in the early detection of subclinical forms of neuropathies and the prevention of disease complications.