Functional MRI of spontaneous brain activity in patients with end-stage renal disease

Objective: To explore the changes of spontaneous brain activity in patients with end-stage renal disease (ESRD) using amplitude of low-frequency fluctuation (ALFF) algorithm in resting state functional MRI (rs-fMRI). Methods: Forty patients with ESRD (23 men, 17 women) and 40 matched healthy controls matched in age, gender and years of education (23 men, 17 women) were enrolled. Neuropsychology scales were used to estimate the cognitive function. Clinical and rs-fMRI data were acquired in all subjects. After rs-fMRI data preprocessing, the difference of ALFF between the two groups was analyzed. The mean ALFF values of significant brain regions were extracted and correlation analysis among the mean ALFF values, clinical data and neuropsychology scales was performed in patients with ESRD. Results: Compared with healthy control, ESRD patients had multidimensional cognitive impairment (P < 0.01), significantly decreased ALFF values in the bilateral precuneus, left postcentral gyrus and left superior temporal gyrus, and increased ALFF values in the bilateral cerebellum lobules VIII (P < 0.05, FWE corrected). There were positive correlations between the mean ALFF values of the bilateral precuneus and red blood cell (r = 0.477, P = 0.002; r = 0.508, P = 0.009), hemoglobin (r = 0.516, P < 0.001; r = 0.469, P = 0.002) and hematocrit (r = 0.557, P < 0.001; r = 0.471, P = 0.002) levels. After controlling all clinical variables involved in this experiment, positive correlations were found between the mean ALFF value of the right cerebellum lobule VIII and TMTA (r = 0.597, P = 0.003) and TMTB (r = 0.555, P = 0.007); between the left postcentral gyrus and FDST (r = 0.552, P = 0.008). Conclusion: ESRD patients have overall cognitive decline with impaired spontaneous brain activity in the bilateral precuneus, left postcentral gyrus and left superior temporal gyrus. Anemia may affect spontaneous brain activity in ESRD patients. (authors)