Objective: To examine neuropsychological and neurologic functioning in systemic lupus erythematosus (SLE) patients without histories of overt neuropsychiatric disorders (non-NPSLE patients).
Methods: Sixty-seven non-NPSLE patients and 29 healthy controls were administered a standardized neurologic examination and measures of cognition, depression, and self-reported cognitive functioning.
Results: Non-NPSLE patients scored lower than controls on the total score of the neurologic examination (P < 0.0001). Item analysis indicated that the physician's description of mentation and mood was the only item that differed significantly between patients with SLE and controls (P = 0.004). Compared with controls, non-NPSLE patients had significantly higher rates of impairment on logical reasoning (P = 0.012) and verbal memory (P = 0.03), and trends toward greater impairment on visual attention (P = 0.06) and working memory (P = 0.098). There were no significant differences between non-NPSLE patients and controls on a cognitive impairment index (CII): 20.9% of non-NPSLE patients and 13.8% of controls were impaired. Patients with SLE scored higher on depressive symptoms (P < 0.0001) and perceived cognitive difficulties (P = 0.001) compared with controls.
Conclusion: The utility of a standardized neurologic examination in SLE for excluding overt neurologic dysfunction and assuring a non-NPSLE group selection was demonstrated. In contrast to our earlier study, we did not find differences between non-NPSLE patients and controls on the CII. Slightly lower CII scores in non-NPSLE patients and higher CII scores in controls may have reduced cognitive differences between these groups. Non-NPSLE patients demonstrate specific decline in the areas of attention, memory, and reasoning; continued studies of associated brain regions are warranted.