The effects of hemodialysis on the functional brain connectivity in patients with end–stage renal disease: A functional near–infrared spectroscopy study

Abstract

Background: This study aimed to investigate functional brain connectivity in patients with end–stage renal disease (ESRD) undergoing hemodialysis using functional near–infrared spectroscopy (fNIRS) and to analyze the effect of hemodialysis on functional brain connectivity. Methods: We prospectively enrolled patients with ESRD undergoing hemodialysis for >six months without any history of neurological or psychiatric disorders. fNIRS data were acquired using a NIRSIT Lite device. Measurements were performed thrice in the resting state for each patient: before the start of hemodialysis (pre–HD), 1 h after the start of hemodialysis (mid–HD), and after the end of hemodialysis (post–HD). We processed and exported all data and created a weighted connectivity matrix using Pearson correlation analysis. We obtained functional connectivity measures from the connectivity matrix by applying a graph theoretical analysis. Then, we compared differences in functional connectivity measures according to hemodialysis in patients with ESRD. Results: We included 34 patients with ESRD. There were significant changes in the mean clustering coefficient, transitivity, and assortative coefficient between the pre– and post–HD periods (0.353 vs. 0.399, p=0.047; 0.523 vs. 0.600, p=0.042; and 0.043 vs. –0.012, p=0.044, respectively). However, there were no changes in the mean clustering coefficient, transitivity, and assortative coefficient between the pre– and mid–HD periods and between the mid– and post–HD periods. In addition, there were no significant differences in the average strength, global efficiency, and local efficiency among the pre–, mid–, and post–HD periods. Conclusions: We demonstrated a significant effect of hemodialysis on functional brain connectivity in patients with ESRD. Functional brain connectivity changes more efficiently during hemodialysis.

Wearable functional near‐infrared spectroscopy for measuring dissociable activation dynamics of prefrontal cortex subregions during working memory

“…We used a wearable frontal lobe fNIRS system with a high‐density channel array ‐ NIRSIT (OBELAB, Korea) ‐ which covers the lateral PFC with 48 main channels with a sampling rate of about 8 Hz and has been used actively in clinical research (Jang et al, 2021; Lee et al, 2021; Park et al, 2023; Yang et al, 2019). In addition, applying a searchlight‐based probabilistic mapping of fNIRS channels on the standard Montreal Neurological Institute (MNI) space (see Section 2) allowed us to get enough spatial resolution to dissociate neural signals originating from distinct subregions of the PFC.…”