The pathogenesis of central nervous system involvement in systemic lupus erythematosus (SLE) is not completely understood. In this study, we investigated the association of microembolic signals (MES) with a variety of neuropsychiatric SLE manifestations and compared our results with those from SLE patients without neuropsychiatric lupus and normal controls. Fifty-three patients with SLE (45 females and 8 males), all fulfilling the revised classification criteria for SLE, and 50 control subjects (44 females and 6 males) were enrolled in this study. All SLE patients were assessed by neuropsychological examination, including various neuropsychiatric tests. Twenty-five patients with SLE were found to have at least one of the neuropsychiatric syndromes defined by The American College of Rheumatology. The mean MES count in patients with neuropsychiatric Jupus was significantly higher than those without (5.4 +/- 1.1 vs. 0.3 +/- 0.8/h; p < 0.005). We found a positive correlation between higher mean MES counts and the presence of neuropsychiatric syndromes in SLE. The mean MES count in the whole group of SLE patients was also significantly higher than that in healthy controls. The mean MES count of SLE patients with antiphospholipid (aPL) antibody positivity was significantly higher than those without aPL antibodies (3.6 +/- 1.6 vs. 0.8 +/- 0.1/h; p < 0.005). In conclusion, the association of MES with neuropsychiatric lupus may support the possible contribution of MES to the complex pathophysiology of this syndrome. More importantly, detection of MES on transcranial Doppler monitoring might suggest a high risk of involvement of the central nervous system in SLE, and could be used as a diagnostic tool. Copyright (C) 2002 S. Karger AG, Basel.