Objectives To find evidence for occult cerebral functional damage resides prior to clinical symptoms by using resting state and task based functional magnetic resonance imaging(fMRI) in systemic lupus erythematosus(SLE) patients without neuropsychological symptoms.
Methods 41 non-neuropsychiatric systemic lupus erythematosus(non-NPSLE) patients and 28 similar control participants were enrolled, performed paced visual serial addition test (PVSAT), and performed both resting state and PVSAT task based fMRI scanning. Data were processed and analysed by SPM8 software package, resting state data were post processed with method called regional homogeneity (ReHo). Difference of ReHo values between patients and controls were compared by independent t test. The activated brain areas of PVASAT tasks were compared in SPM8, and functional connectivity of these areas were tested in resting state data.
Results During resting state, compared to the controls, non-NPSLE subjects displayed significantly decreased ReHo values in multiple areas including the bilateral 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 and cingulate gyrus; ReHo was increased in bilateral cuneus and in the calcarine gyrus
Both groups had no significant difference in PVSAT test. In PVSAT task based fMRI, in control subjects, the activations were situated in left superior and inferior parietal lobe, and left inferior frontal gyrus. While for non-NPSLE patients, significantly extended activations were found in left hemisphere in superior and inferior parietal lobe, superior, middle and inferior frontal gyrus. Brain areas activated in healthy controls were selected as regions of interest (ROIs) to test for the functional connectivity strength between patients and controls. Compared with controls, non-NPSLE patients exhibited a significantly higher magnitude of connectivity strength between areas activated during working memory task.
Conclusions During resting state, non-NPSLE patients exhibited alteration of major areas of default mode network; while significantly expanded areas of activation in task based fMRI, both resutls demonstrated that cerebral damage existed prior to the presentation of any neuropsychological symptoms.
Disclosure of Interest None Declared