Alterations of cerebral glucose metabolism indicate progress to severe morphological brain lesions in neuropsychiatric systemic lupus erythematosus

Neuropsychiatric systemic lupus erythematosus (SLE) is frequently associate d with deficits in brain glucose metabolism, even if morphological imaging by magnetic resonance imaging (MRI) shows no abnormalities. In these patien ts it is unclear whether or not the changes of brain metabolism measured by F-18-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) may p rogress to lesions of cerebral structure. We describe a 20-year-old woman w ith SLE who presented with depression, headache and impairment of memory. i nitially, a cranial MRI was negative, but FDG-PET revealed significant hypo metabolism in the frontal and parieto-temporo-occipital regions on both sid es as well as hypermetabolism in the nuclei caudati. Within two months the patient developed an acute confusional state, seizures, visual disturbances and cranial MRI became positive showing hyperintensities at the basal gang lia and the temporo-occipital regions. Focal cerebral symptoms responded to treatment with high dose corticosteroids and brain lesions in MRI disappea red. However, a second FDG-PET showed persistent hypometabolism at frontal regions in accordance with the persistence of subclinical depression. To ou r knowledge, this is the first SLE case report showing that functional brai n lesions visualized by FDG-PET may be a risk factor for subsequent structu ral brain damage seen in MRI. Thus, FDG-PET may help to verify cerebral inv olvement of SLE earlier than MRI.