Purpose: This study aimed to investigate the topological organization of intrinsic functional brain networks in patients with end-stage renal disease (ESRD).
Materials and methods: Resting-state functional MRI data were collected from 22 patients with ESRD (16 men, 18-61 years) and 29 age- and gender-matched healthy controls (HCs, 19 men, 32-61 years). Whole-brain functional networks were obtained by calculating the interregional correlation of low-frequency fluctuations in spontaneous brain activity among 1,024 parcels that cover the entire cerebrum. Weighted graph-based models were then employed to topologically characterize these networks at different global, modular and nodal levels.
Results: Compared to HCs, the patients exhibited significant disruption in parallel information processing over the whole networks (P < 0.05). The disruption was present in all the functional modules (default mode, executive control, sensorimotor and visual networks) although decreased functional connectivity was observed only within the default mode network. Regional analysis showed that the disease disproportionately weakened nodal efficiency of the default mode components and tended to preferentially affect central or hub-like regions. Intriguingly, the network abnormalities correlated with biochemical hemoglobin and serum calcium levels in the patients. Finally, the functional changes were substantively unchanged after correcting for gray matter atrophy in the patients.
Conclusion: Our findings provide evidence for the disconnection nature of ESRD's brain and therefore have important implications for understanding the neuropathologic substrate of the disease from disrupted network organization perspective.