Primary Sjogren syndrome (PSS) is an autoimmune disease characterized by symptoms of a dry mouth and eyes, in which other organs and systems are widely involved. Central nervous system (CNS) involvement in PSS is reported in a wide range between 2.5-60%. The reason is that the clinical picture can remain asymptomatic despite the presence of CNS involvement in the disease process. In this study, our aim was to evaluate subclinical cognitive impairment in patients with PSS by investigating P300 potential parameters.
Forty-three female patients with PSS (mean age: 52.6 ± 11.4 years) and 35 healthy female controls (mean age: 54.5 ± 8.09 years) were included in the study. Mini-Mental State evaluations (MMSE) and brain MRI were performed in the patient and control groups. An event-related evoked potentials test (P300) was applied to those with normal MMSE.
The P300 latencies of patients with PSS were significantly longer compared with the control group (p = .019). In patients with PSS, there was no difference in P300 parameters between ANA, Anti-SSA, Anti-SSB-positive and negative patients, and patients with or without sedimentation and CRP elevation. In addition, brain MRI revealed no statistically significant difference between patients with PSS with and without ischemic gliotic lesions (p=.48).
In our study, P300 latency was also found to be significantly longer in patients who had no white matter change. We believe that prolonged P300 potential latencies without associated white matter lesions in brain imaging may be associated with subclinical CNS involvement.