Prevalence and characteristics of immunomediated neuropathies in a group of patients with autoimmune diseases.

OBJECTIVE: To determine the prevalence and the clinical-neurophysiological characteristics of immunomediated peripheral neuropathies (PN) in a group of patients with systemic autoimmune diseases. METHOD: Fifty-nine patients with proved systemic autoimmune diseases were included. Patients underwent clinical examination and nerve conduction studies to diagnose the PN. RESULTS: Immune PNs were detected in 18 patients (30.5%). Out of the total number of PNs (18), 39% were sensory-motor polyneuropathies, 33% mononeuritis multiplex, 11% pure sensory polyneuropathies, 11% cranial neuropathies, and 6% proximal motor neuropathies, such as the Guillain-Barré syndrome. Nine PNs (50%) appeared at the onset of the connective tissue disorders, and the rest of the cases appeared during the course of the disease. Of the total of PNs detected in this study, only 45% had a previous diagnosis. Vasculitis was the disease that presented more associated PNs. Systemic lupus erythematosus showed the widest range of PN clinical varieties. CONCLUSIONS: The first national prevalence rate of PNs in patients with systemic autoimmune diseases was provided: 30.5%. No comparative data were found in the international bibliography. Sensory-motor polyneuropathy was the most frequently observed form of PN, followed by mononeuritis multiplex. The NPs appeared with the same frequency both at the onset and during the course of the diseases under study; these predominated at the onset of vasculitis and primary Sjögren syndrome. The compromise of the peripheral nervous system is underdiagnosed.