Brain white matter microstructural alterations in patients with systemic lupus erythematosus: an automated fiber quantification study.

This study aimed to identify damaged segments of brain white matter fiber tracts in patients with systemic lupus erythematosus (SLE) using diffusion tensor imaging (DTI)-based automated fiber quantification (AFQ), and analyze their relationship with cognitive impairment. Clinical and imaging data for 39 female patients with SLE and for 44 female healthy controls (HCs) were collected. AFQ was used to track whole-brain white matter tracts in each participant, and each tract was segmented into 100 equally spaced nodes. DTI metrics including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were calculated at each node. Correlations were also explored between DTI metrics in the damaged segments of white matter fiber tracts and neuropsychological test scores of patients with SLE. Compared with HCs, SLE patients exhibited significantly lower FA values, and significantly higher MD, AD, RD values in many white matter tracts (all P < 0.05, false discovery rate-corrected). FA values in nodes 97-100 of the left inferior fronto-occipital fasciculus (IFOF) positively correlated with the mini-mental state examination score. AFQ enables precise and accurate identification of damage to white matter fiber tracts in brains of patients with SLE. FA values in the left IFOF correlate with cognitive impairment in SLE.

Aberrant changes of dynamic global synchronization in patients with Parkinson's disease.

BACKGROUND: Patients with Parkinson's disease (PD) have been documented with disrupted dynamic profiles of functional connectivity. However, the complementary information that is relevant to the dynamic pattern of global synchronization in patients with PD requires further investigation. PURPOSE: To reveal the aberrant dynamic profiles of global synchronization involved in PD with a focus on temporal variability, strength, and property. MATERIAL AND METHODS: A total of 46 patients with PD and 50 matched healthy controls (HCs) were enrolled. Degree centrality (DC) was used as the metric of global synchronization. The intergroup differences in the dynamic DC (dDC) pattern were compared, followed by further analysis of their clinical relevance in PD. RESULTS: Relative to HCs, the PD group showed decreased dDC variability in right inferior occipital gyrus, right insula, right middle occipital gyrus (MOG), and bilateral postcentral gyrus. The dDC variability in the MOG was significantly correlated with MoCA score. Two states (state I and state II) were suggested. Relative to HCs, the PD group demonstrated a shorter mean dwell time (MDT) in state I, a longer MDT in state II, and fewer transitions. For the PD group, dDC properties were significantly correlated with UPDRS-III scores. In state II, significantly decreased dynamic dDC strength in bilateral supplementary motor area was observed in the PD group, with a significant correlation with UPDRS-III scores. CONCLUSION: These findings on PD imply that dynamic alterations of global synchronization are engaged in the dysfunction of movement and cognition, deepening the understanding of deteriorations that underlie PD with complementary evidence.

Altered degree centrality in patients with non-neuropsychiatric systemic lupus erythematosus: a resting-state fMRI study.

This study used a voxel-wise degree centrality (DC) method to evaluate differences in brain activity between patients with non-neuropsychiatric systemic lupus erythematosus (non-NP-SLE) and healthy controls (HCs) and to assess the relationship of DC values with clinical and neuropsychological data. Thirty-two female patients with non-NP-SLE and 28 well-matched HCs were recruited and underwent resting-state functional MRI. Differences in spontaneous brain activity between the two groups were evaluated using a DC method. Correlations between the altered DC values of specific brain regions and clinical and neuropsychological data were explored using Spearman correlation analysis. Receiver operating characteristics curve analysis was applied to differences in DC values in specific brain regions to determine their value in distinguishing patients with non-NP-SLE from HCs. Compared with HCs, DC values in patients with non-NP-SLE were significantly lower in the bilateral postcentral gyrus and the orbital part of the left superior frontal gyrus (LFMO). DC values in some specific brain regions such as the bilateral postcentral gyrus and the LFMO correlated with Mini-Mental State Examination scores in both subject groups. In patients with non-NP-SLE, DC values of the right postcentral gyrus were positively correlated with IgA levels, and DC values of the LFMO were positively correlated with Systemic Lupus Erythematosus Disease Activity Index 2000 scores, as well as IgA levels. Receiver operating characteristics curve analysis revealed that the DC values of specific brain regions can be used to differentiate patients with non-NP-SLE from HCs.