In patients with systemic lupus erythematosus (SLE), to determine 1) the prevalence and clinical features of peripheral neuropathies (PN) and whether they were SLE related, 2) whether there are associations between other SLE features and PN.
Patients who met the American College of Rheumatology case definition criteria for SLE peripheral neuropsychiatric syndromes were selected from the University of Toronto Lupus Clinic database. Demographic data and SLE-related clinical and laboratory data were extracted. Health-related quality of life was assessed using the mental and physical component summary score of the SF-36 questionnaire. In a nested case-control study, SLE patients with PN were matched by disease duration and compared with those without PN.
Of 1533 patients in the database, 207 (14%) had PN. Of these, 40% were non-SLE-related. Polyneuropathy was diagnosed in 56%, mononeuritis multiplex in 9%, cranial neuropathy in 13%, and mononeuropathy in 11% of patients. Asymmetric presentation was most common (59%) and distal weakness occurred in 34%. Electrophysiologic studies indicated axonal neuropathy in 70% and signs of demyelination in 20% of patients. Compared with patients without PN, those with PN had significantly more central nervous system involvement, higher SLE-disease activity index 2000 and lower SF-36-PCS.
The prevalence of PN is relatively high in SLE and occurs more frequently in patients with central nervous system involvement and high SLE-disease activity index. There is a predilection for asymmetric and lower extremities involvement, especially peroneal and sural nerves. This manifestation of the disease has a significant impact on the patient's quality of life.