A BSTRACT Introduction: Systemic lupus erythematosus (SLE) and primary Sjögren’s disease (pSD) are autoimmune connective tissue disorders that can involve both the central nervous system (CNS) and peripheral nervous system (PNS). SLE typically affects the CNS, whereas pSD more frequently involves the PNS. Materials and Methods: This study investigated subclinical neurologic involvement in 30 patients with SLE (27 females) and 31 patients with pSD (all female), compared with age- and sex-similar healthy controls (17 for SLE and 15 for pSD), all of whom were asymptomatic neurologically. Nerve conduction studies were used to assess PNS involvement, motor-evoked potentials (MEPs) for CNS involvement, and the Standardized Mini-Mental State Examination (SMMSE) for cognitive involvement. Results: There were no significant differences in age, height, or weight between the groups. No pathologic findings were detected in nerve conduction or MEP studies among the patients with SLE and controls. In the pSD group, two (6.4%) patients exhibited peripheral neuropathy findings, although MEPs were normal in all participants. Only one (3.3%) patient with SLE scored 20 on the SMMSE; all others scored 24 or higher. Discussion: The absence of MEP abnormalities supports prior findings in rheumatologic cohorts. The 6.4% PNS involvement rate in pSD is consistent with earlier data, though lower than recent reports (20%–25%), likely due to the exclusion of symptomatic individuals. The low incidence of cognitive impairment in SLE may reflect the screening nature of the SMMSE and preselection of patients without overt cognitive deficits during initial evaluations. Prospective studies with larger samples are needed in this field.
Tunçel et al. (Tue,) studied this question.