Altered intrinsic brain activity and memory performance improvement in patients with end-stage renal disease during a single dialysis session

Memory deficits are considered to have a great influence on self-management, dietary restriction and therapeutic regimen for end-stage renal disease (ESRD) patients with dialysis treatment. This study was aim to investigate the spontaneous brain activity and its relationship with memory performance in ESRD patients before dialysis (T1) and after 24 h (T2) during a single dialysis session. 23 ESRD patients and 25 matched healthy controls (HCs) were scanned using functional magnetic resonance imaging (fMRI) at T1, and all patients were also scanned at T2. Amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) methods were used to evaluate the spontaneous brain activity between two groups. The Auditory Verbal Learning Test-Huashan version (AVLT-H) was performed to assess memory function. Compared with HCs, ESRD group showed a significant decreases in the immediate recall total score (IR-S), short-term delayed recall score (SR-S), and long-term delayed recall score (LR-S) at T1. IR-S, SR-S, LR-S and recognition score (REC-S) were significantly increased at T2. Compared with HCs at T1, ESRD patients showed that the lower mean ALFF (mALFF) values were mainly located in dorsolateral prefrontal cortex (DLPFC), medial frontal gyrus, and precuneus. Higher ReHo in the bilateral inferior temporal gyrus and left hippocampus and lower ReHo in the right precentral gyrus, anterior cingulate cortex were found at T1 too. The mALFF values of the DLPFC and precuneus were significantly increased during a dialysis session, while no significantly difference of ReHo region was found. Furthermore, the increased mALFF values of the DLPFC were significantly positively correlated with the improvement in the IR-S. Our results indicated that increased regional spontaneous activity of the DLPFC may reflect memory performance improvement after a single dialysis treatment, which may provide insight into the effect of hemodialysis on spontaneous brain function during a single dialysis session.