Peripheral neuropathy in primary Sjogren syndrome - A population-based study

Background: Neurological manifestations appear to be frequently involved in patients with primary Sjogren syndrome (PSS). Objective: To investigate the involvement of the peripheral nervous system, including small-diameter nerve fibers, in an unselected cohort of patients who fulfilled the new international criteria for PSS. Design: Cross-sectional study. Setting: Stavanger University Hospital. Patients: Sixty-two patients with PSS (mean +/- SD age, 57.1 +/- 14.6 years). Interventions: Clinical neurologic examinations, conventional nerve conduction studies, and skin punch biopsies. Main Outcome Measures: Signs of large-diameter and small-diameter peripheral nerve fiber neuropathy as determined by clinical examination, nerve conduction studies, and densities of intraepidermal nerve fibers in skin punch biopsy specimens. Results: Seventeen patients (27%) were diagnosed as having neuropathy after clinical examination. The results of nerve conduction studies were abnormal in 34 patients (55%): 19 patients (31%) had motor neuropathy, 8 (13%) had sensory neuropathy, and 7 (11%) had sensorimotor neuropathy. Two patients had intraepidermal nerve fiber densities less than 3.4 fibers per millimeter, fitting the morphologic criteria for small-diameter nerve fiber neuropathy. Conclusions: Peripheral neuropathy occurs in a large proportion of patients with PSS, in most cases as a subclinical demyelinating neuropathy. Small-diameter nerve fiber neuropathy is not a frequent finding in these patients.