The authors compared the size of the focal white matter hyperintensities in T2 weighted images in MR findings of 50 patients with neuropsychiatric lupus (NPSLE) and multiple sclerosis (MS) in correlation with controls. The hypothesis, that the size and the number of lesions differ statistically significantly among the groups of investigated persons was checked in the study. In patients with NPSLE the significant prevalence of lesions up to 3mmand their occurrence in parietal and frontal lobes was proved. In patients with MS there were the lesions totally more frequent, the lesions up to 3 mm were the most frequent and significantly prevailed the frontoparietal localization. The greater wedge – shaped lesions were present only in NPSLE patients in up to 10% and corresponded to cerebral infarctions. In conclusion: there were significant differences in the total numbers of pathological lesions in the brain and also in different cerebral lobes either among all groups together, or between the patient groups and controls. There were no statistically significant differences in the lesion size among the groups. Pathological lesion in NPSLE cannot be differentiated from RS patients according to MR findings.

        Key words: neuropsychiatric lupus – multiple sclerosis – cerebral MR – differences