28 Cognitive dysfunction in systemic lupus erythematosus

This chapter reviews neuropsychological assessment strategies, and examines the data from numerous studies regarding the prevalence of cognitive deficit in systemic lupus erythematosus (SLE) patients. Broad-based neuropsychological assessment strategies have proved to be sensitive to the presence of cognitive impairment in patients with SLE, and have uncovered significant impairment even in patients without overt neurologic or psychiatric symptomatology. Although responses to self-report questionnaires indicate emotional distress in a fair number of SLE patients, a significant association between the presence of cognitive impairment and distress is not evident. Moreover, the documented cognitive impairment cannot be attributed to possible adverse side effects of corticosteroids, and is not strongly associated with the presence of active disease. Thus, cognitive impairment, when documented in SLE patients, most likely reflects central nervous system dysfunction; this may be residual, in the case of patients with inactive CNS symptomatology, or perhaps an early marker or predictor of CNS involvement, in the case of patients who have never had major CNS symptomatology. It is important to note that there is limited concordance among the deficits that are identified by directly comparing control and SLE groups and the deficits that are identified in individual test protocols, applying decision criteria commonly used in clinical neuropsychological assessment. This suggests a relatively limited clinical utility for data from group studies, no matter what the patient population, unless there is a well established homogeneity in neurologic presentation.