Peripheral nervous system disease, predominantly neuropathies, constitutes a substantial proportion of the manifestations of neuropsychiatric systemic lupus erythematosus (SLE) and has a lasting negative impact on health-related quality of life, John G. Hanly, MD, of Queen Elizabeth II Health Sciences Center and Dalhousie University, Halifax, N.S., and associates reported in Arthritis & Rheumatology.
According to the study of 1,827 SLE patients who had been recently diagnosed and enrolled in the Systemic Lupus International Collaborating Clinics (SLICC) network at sites in Europe, Asia, and North America during 1999-2011, 161 peripheral nervous system (PNS) events occurred in 139 of the patients (8%) over a mean 7.6 years of follow-up.
Using the seven American College of Rheumatology case definitions for PNS disease in neuropsychiatric SLE, most of the events were peripheral neuropathy (41%), mononeuropathy (27%), and cranial neuropathy (24%). For 110 with peripheral neuropathy or mononeuropathy who underwent electrophysiologic testing, axonal damage was often present (42%), followed by demyelination (22%).
The PNS events were attributed to SLE in about 58%-75% of the patients. Based on these data the investigators estimated that after 10 years the cumulative incidence of any PNS event regardless of its attribution was about 9%, and it was nearly 7% for events attributed to SLE.
The probability that the neuropathies would not resolve over time was estimated at about 43% for peripheral neuropathy, 29% for mononeuropathy, and 30% for cranial neuropathy. Resolution of neuropathy was most rapid for cranial neuropathy, followed by mononeuropathy and peripheral neuropathy.
Patients with PNS events had significantly lower physical and mental health component scores on the 36-item Short Form Health Survey than did patients without a neuropsychiatric event up to the study assessment, and these differences persisted for 10 years of follow-up.
These “findings provide a benchmark for the assessment of future treatment modalities,” the investigators concluded.
SOURCE: Hanly JG et al. Arthritis Rheumatol. 2019 Aug 7. doi: 10.1002/art.41070.