Extraglandular neurological manifestations of Sjögren's syndrome are increasingly recognized, defining the disease entity of Neuro-Sjögren. Neuropsychological assessment of patients with Sjögren's syndrome has hitherto been performed on predominantly rheumatological cohorts. These studies revealed a wide variety of prevalence rates for cognitive impairment (22-80%), while variable cut-off criteria for detection of cognitive impairment were applied. Attentional functions have not yet been thoroughly investigated in these patients, although they clearly represent relevant aspects of cognitive functioning in daily life.

We therefore conducted extensive neuropsychological assessment based on two neuropsychological test batteries [i.e., the extended German version of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery (CERAD-PLUS), and the test battery for attentional performance (TAP) as a well-established assessment of attentional functions in the German-speaking part of Europe].

Sixty-four patients with Neuro-Sjögren, who were treated at our university hospital between December 2016 and January 2019, were included. Evidence for the presence of cognitive impairment was found in 55% of patients with Neuro-Sjögren. The degree of cognitive impairment ranged from mild (38%) to severe (17%). Attentional and mnemonic subtests showed pronounced cognitive impairment in patients with Neuro-Sjögren.

Our results suggest that a substantial proportion of patients with Neuro-Sjögren suffer from cognitive impairment, putatively as a corollary of attentional deficits, which might exert adverse effects on occupational abilities, other cognitive functions, and social role functioning.