In order to test the hypothesis whether the pathogenesis of cerebral systemic lupus erythematosus (SLE) may include an immune-mediated deficit in specific vulnerable brain regions, the regional cerebral metabolism in 9 patients with diffuse as well as focal cerebral symptoms was compared with that of 10 age-matched control subjects. The cerebral distribution of 2-[¹⁸F]fluoro-2-deoxy-D-glucose (FDG) uptake was measured by means of positron emission tomography. Subsequently performed statistical parametric mapping showed (i) a relative increase in metabolism in the striatum and (ii) regional decreases in the premotor cortex as a common feature in the patient group. Region of interest measurements of absolute FDG uptake confirmed these findings. The increased striatal activity may support the presence of a direct immune response against neuronal tissue in SLE, similar to the cross-reaction against inhibitory components in striatal tissue provoked by streptococcal antigens.