Exploring brain metabolism and cognitive impairment in childhood-onset systemic lupus using fluorodeoxyglucose positron emission tomography

OBJECTIVES: As biochemical and functional abnormalities often precede structural changes in disease, fluorine-18 fluorodeoxyglucose positron emission tomography may allow early detection of cerebral involvement in neuropsychiatric lupus. This study evaluated the correlation between cerebral glucose metabolism, assessed by fluorodeoxyglucose positron emission tomography, and cognitive impairment in young adults with childhood-onset systemic lupus. METHODS: Twenty-one patients with childhood-onset systemic lupus underwent clinical and neuropsychological assessment, followed by fluorodeoxyglucose positron emission tomography brain imaging. Scans were compared with those of 22 healthy female controls. Images were non-rigidly registered to a standardized template, allowing voxel-wise analysis using adjusted t-tests. Associations between metabolism and cognitive performance were analysed using Pearson and Spearman correlation coefficients and Student's t-tests. RESULTS: Hypometabolism was observed in the cerebellum, parietal, occipital, limbic, and frontal lobes, while hypermetabolism in the sub lobar region, temporal lobe, and areas of the limbic and frontal lobes. Memory deficits correlated with hypermetabolism in the left hemisphere, Brodmann area 13; attention impairments with hypermetabolism in area 20 and hypometabolism in areas 7 and 18; and executive dysfunction with hypometabolism, particularly in the left hemisphere. CONCLUSION: Fluorodeoxyglucose positron emission tomography may assist in identifying early functional brain abnormalities related to cognitive dysfunction in childhood-onset systemic lupus.