Regional specific changes of cerebral metabolism in systemic lupus erythematosus identified by positron emission tomography

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.