Cognitive and neurologic status in patients with systemic lupus erythematosus without major neuropsychiatric syndromes.

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.