Normalization of Cerebral Blood Flow, Neurochemicals, and White Matter Integrity After Kidney Transplantation

Abstract

Background: Chronic kidney disease (CKD) is associated with abnormalities in cerebral blood flow (CBF), cerebral neurochemical concentrations and white matter integrity, each of which are associated with adverse clinical consequences in the non-CKD population, and may explain the high prevalence of dementia and stroke in end stage kidney disease (ESKD). Since cognition improves after kidney transplantation (KT), we examined these brain abnormalities pre-to post-KT to identify potential reversibility in ESKD-associated brain abnormalities. Methods: We measured the effects of KT on CBF assessed by arterial spin labeling, cerebral neurochemical concentrations (N-acetylaspartate, choline, glutamate and glutamine, myo-inositol and total creatine) measured by magnetic resonance spectroscopic imaging, and white matter integrity measured by fractional anisotropy (FA) and mean diffusivity (MD) with diffusion tensor imaging. We used a linear mixed model analysis to compare longitudinal, repeated brain MRI measurements pre-KT, and 3 months and 12 months post-KT, and also compared findings with healthy controls. Results: 29 ESKD patients and 19 age-matched healthy controls participated in the study. 22 patients underwent post-KT MRI. CBF, which was higher pre-KT than in controls (p=0.003), decreased post-KT (p<0.0001) to values in controls. KT also normalized concentrations of osmotic neurochemicals choline (p<0.0001) and myo-inositol (p=0.0003) that were higher pre-KT compared to controls. Post-KT, FA increased (p=0.001) and MD decreased (p=0.0001). Conclusions: Brain abnormalities in CKD are reversible and normalize with KT. Further studies are needed to understand the mechanisms underlying these brain abnormalities and to explore interventions to mitigate them even in patients who cannot be transplanted.

Advances in differential diagnosis of cerebrovascular diseases in magnetic resonance imaging: a narrative review

“…This is achieved by magnetic resonance spectroscopic imaging (MRSI). MRSI is a molecular imaging technique that can noninvasively map metabolite distributions without labeling, and serves as biomarkers for tumor characterization in the brain (13,14). Spectroscopic imaging with MRSI can distinguish vascular from parenchymal disorders and to discern primary from secondary disease manifestations for abnormalities in cerebral blood flow.…”

Uremic encephalopathy

“…[58][59][60][61] These amino acids do not conform to the classical definition of "uremic toxins", 62 as the data for glycine and glutamate do not unequivocally point to accumulation in CKD while circulating branched chain amino acids are decreased. [63][64][65][66][67][68][69]…”

Application of 9.4 Tesla resting-state functional MRI to Assess Neuronal function and Detect Microglial Density in AKI Rat Model

“…Diffusion tensor imaging (DTI) has been widely applied in kidney induced brain white matter abnormalities for its ability in providing information of white matter microstructural integrity [7,8] Researchers reported the degeneration of main white matter ber tracts in kidney disease induced neurological disorders on diffusion tensor imaging (DTI) modality [9,10]. In addition, some scholars used arterial spin labeling (ASL) to assess the alterations of cerebral blood ow in kidney diseases.…”

“…In addition, some scholars used arterial spin labeling (ASL) to assess the alterations of cerebral blood ow in kidney diseases. They found that the main gray matter cerebral blood decreased in chronic kidney disease (CKD) comparable to healthy controls [9,11]. With previous studies on brain alteration in CKD group, however, studies on AKI induced brain abnormalities are sparse.…”