Sjögren’s syndrome with and without neurological involvement

Objective Neurological manifestations of Sjögren’s syndrome can be severe but also treatment-responsive. We aimed to systematically evaluate neurological manifestations of primary Sjögren’s syndrome and find clinical features allowing sufficient identification of affected patients (pSSN) among those with Sjögren’s syndrome without neurological involvement (pSS). Methods Para-/clinical features of patients with primary Sjögren’s syndrome (2016 ACR/EULAR classification criteria) were compared between pSSN and pSS. At our university-based center, patients with suggestive neurological symptoms undergo screening for Sjögren’s syndrome, and newly diagnosed pSS patients are thoroughly evaluated for neurologic involvement. pSSN disease activity was rated by the Neurological Involvement of Sjögren’s Syndrome Disease Activity Score (NISSDAI). Results 512 patients treated for pSS/pSSN at our site between 04/2018 and 07/2022 were included (238 pSSN patients [46%] vs. 274 pSS patients [54%], cross-sectional design). Independent predictors of neurological involvement in Sjögren’s syndrome were male sex [ p < 0.001], older age at disease onset [ p < 0.0001], hospitalization at first presentation [ p < 0.001], lower IgG levels [ p = 0.04] and higher eosinophil values (treatment-naïve) [ p = 0.02]. Univariate regression additionally showed older age at diagnosis [ p < 0.001], lower prevalence of rheumatoid factor [ p = 0.001], SSA(Ro)/SSB(La) antibodies [ p = 0.03; p < 0.001], higher white blood cell count [ p = 0.02] and CK levels [ p = 0.02] (treatment-naïve) in pSSN. Interpretation Patients with pSSN had different clinical characteristics than patients with pSS and represented a large proportion of the cohort. Our data suggest that neurological involvement in Sjögren’s syndrome has been underestimated. Intensified screening for neurologic involvement should be included in the diagnostic algorithm for Sjögren’s syndrome, especially in males of older age and with severe disease course requiring hospitalization.