Objective: To investigate the prevalence of cognitive dysfunction in randomly selected patients with systemic lupus erythematosus (SLE).
Methods: Randomly selected, ambulatory patients with SLE (n = 49) or with rheumatoid arthritis (RA) (n = 40) completed neuropsychological tests. These included Associate Learning, Switching Attention, Continuous Performance, Associate Recall, Hand-Eye Coordination, Pattern Comparison, Pattern Memory, the Stroop Color and Word Test, and the Symptoms Checklist-90R. Results were evaluated by multiple linear regression analysis.
Results: SLE patients had poorer performance than RA patients on the test of attention (P = 0.002) and tests of visuospatial ability (P = 0.03) and P = 0.04), independent of age, education, or steroid use. The conservative level of statistical significance, adjusting for multiple comparisons, was 0.005. SLE patients reported more symptoms of cognitive difficulty.
Conclusion: Cognitive dysfunction is common in ambulatory SLE patients as measured by standardized tests and is a cause of distress and impaired functioning. Self-reported cognitive difficulty appears to correlate with objective performance.