Electrophysiological evaluation of upper extremity entrapment neuropathies in rheumatic diseases

Systemic inflammation in rheumatic diseases (RDs) can affect the peripheral nervous system, leading to neuropathic and myopathic complications. This study aimed to assess the frequency of upper extremity entrapment neuropathies in patients with RDs and identify associated predictive variables. A secondary objective was to highlight the role of electroneuromyography (ENMG) in early diagnosis and awareness about these issue. In this cross-sectional study, 102 patients diagnosed with RDs were evaluated. Demographic and clinical data, including disease duration, medications, joint involvement, and comorbidities, were recorded. Laboratory parameters such as rheumatoid factor, cyclic citrullinated peptide, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were recorded. Patients were referred for nerve conduction studies performed according to the American Academy of Neurology standards. Disease activity was measured using the Disease Activity Score 28 for rheumatoid arthritis (RA), Disease Activity Score for psoriatic arthritis (PsA), and European League Against Rheumatism Sjögren Syndrome Disease Activity Index for Sjögren syndrome. The frequency of carpal tunnel syndrome was 50% in RA, 47.4% in PsA, and 22.2% in Sjögren syndrome patients. Additionally, 9.5% of RA patients had cubital tunnel syndrome. Positive ENMG findings were weakly correlated with age (r = 0.234; P = .018), RD (r = 0.221; P = .026), ESR (r = 0.216; P = .029), CRP (r = 0.229; P = .02), disease activity (r = 0.354; P < .001), and comorbidities (r = 0.229; P = .02). Moderate correlations were observed with disease duration (r = 0.432; P = .037) and the side affected by the lesion (r = 0.447; P < .001). In ordinal regression analysis, age and CRP had a nonsignificant positive effect on abnormal ENMG results. Disease duration, ESR, diagnosis (RA/PsA), disease activity, and comorbidities showed a nonsignificant negative effect on the likelihood of normal ENMG findings. The affected side was significantly associated with ENMG results; compared to bilateral involvement, right-sided neuropathy had a 1.5% and left-sided 4.3% chance of normal ENMG results. In RD patients with symptoms such as wrist or elbow pain, tingling, or numbness, peripheral neuropathies should be considered. ENMG is a critical tool for early diagnosis, as it offers detailed insights into lesion localization, severity, and prognosis.