A Research Of Functional Magnetic Resonance In Systemic Lupus Erythematosus

Background：Systemic lupus erythematosus (SLE) is a autoimmune disease thatbrings severe damage to virtually all systems in the body, while neuropsychologicalsystemic lupus erythematosus (NPSLE) is the common complication with unknownpathogenesis. The quality of life was greatly degraded due to limited activities brought byneurological and psychological disorders, highlighting the importance of its early dignosisand intervention. By using functional magnetic resonance imaging (fMRI), more insights ofhave been discovered, however one important question has not been answered: whetheroccult functional damage resides prior to clinical symptoms?Objective：To explore the evidence of cerebral functional deficits exists prior toclinical presentation, by using fMRI methods testing SLE patients withoutneuropsychological symptoms.Methods：The experiment enrolled41non-NPSLE patients, with clinical indexes suchas disease course, corticosteroids dosage documented, all patients were evaluated forsystemic lupus erythematosus disease activity index (SLEDAI) score, performed pacedvisual serial addition test (PVSAT) outside scanner, and scanned for both resting state andPVSAT task based fMRI.28age and gender matched healthy subjects performed PVSATand sequential fMRI scanning. Image data were processed and analysed by SPM8softwarepackage, and resting state data were analyzed by a method called regional homogeneity(ReHo). ReHo values between patients and controls were compared by independent t test,and test for correlation with glucocorticosteroid dosage and SLEDAI scoring. Brainactivation areas performing PVASAT task were compared using SPM8, and the strength offunctional connectivity of these areas were evaluated by using resting state data, whichwere then tested for correlaton with with GC dosage and SLEDAI scoring.Results：In resting state, two sample t-test (whole brain analysis) demonstrated that,non-NPSLE subjects had apparently decreased ReHo values in several areas including thebilateral posterior lobes of the cerebellum (predominantly in crus I and II of the neocerebellum), the vermis, left inferior frontal gyrus, left precuneus, right limbic lobe andcingulate gyrus; and increased ReHo value in bilateral cuneus and in the calcarine gyrus.Furthermore, SLEDAI score achieved positive correlation with generalized ReHo value inleft cerebellum posterior lobe and left ACC (P <0.01), whereas there were no correlationsbetween GC dosage and regional ReHo values.Both groups performed equally well in PVSAT test. However in task-based fMRI,significantly extended activations were found in left hemisphere in superior and inferiorparietal lobe, superior, middle and inferior frontal gyrus in non-NPSLE patients. Such resultindicated that, to accomplish working memory task, non-NPSLE patients utilized a broaderrange of brain regions than controls. Brain areas activated in healthy controls duringPVSAT task were selected as regions of interest (ROIs) to test for the functionalconnectivity strength between patients and controls. Compared with controls, non-NPSLEpatients exhibited a significantly higher magnitude of connectivity strength between areasactivated during working memory task and were positively correlated with SLEDAI scoringbut not with GC dosage.Conclusion:1. Major areas of the default mode network (DMN) were attenuated in non-NPSLEpatients.2..The cerebellum was attenuated in non-NPSLE patients，and the ReHo value fromthe cerebellum was correlated with SLEDAI score but not with GC dosage.3. Non-NPSLE patients presented intact PVSAT performance, however exhibitedsignificantly broader areas of activation than controls in fMRI scanning, which indicatedthat such changes in activation patterns may represent a plastic response to disease-relatedcerebral damage, and thus an attempt to compensate for the deficit due to brain injury.4. Non-NPSLE patients exhibited a significantly higher magnitude of functionalconnectivity between parietal lobe and inferior frontal gyrus，and SLEDAI score has beencorrelated with the connectivity strength in patients.