Cerebrovascular Function is Altered in Hemodialysis Patients

Abstract

Introduction: Hemodialysis (HD) patients have declines in cerebral blood flow (CBF) and cerebral oxygenation during HD that may lead to ischemic brain injury. Cerebrovascular reactivity (CVR) may indicate which individuals are more susceptible to intradialytic hypoperfusion and ischemia. We hypothesized that HD patients would have decreased CVR and increased CBF relative to controls and deficits in CVR would be related to brain structural deficits. Methods: We measured cortical thickness and white matter hyperintensity (WMH) volume from T1 and T2 FLAIR images respectively, CVR from a breath hold BOLD CVR fMRI and arterial transit time (ATT) and CBF from ASL. Cerebrovascular and structural deficits in gray and white matter (GM and WM) were tested by averaging across the tissue and with a pothole analysis. Finally, we correlated cortical thickness and WMH volume with GM and WM cerebrovascular variables to assess the relationship between brain structure and cerebrovascular health. Results: In ten HD patients, cortical thickness was found to be decreased (p= 0.002), WMH volume increased (p=0.004), and WM CBF increased (p=0.02) relative to ten controls. Pothole analysis indicated a higher number of increased GM and WM CBF voxels (p=0.03, p=0.02) and a higher number of decreased GM and WM CVR voxels (p=0.02, p=0.01). Conclusions: This pilot study demonstrates that HD patients have decreased CVR and increased CBF relative to controls, along with reduced brain integrity. Further investigation is required to fully understand if these cerebrovascular deficits may lead to structural changes.