Cognitive outcome following kidney transplantation

Background. While a handful of studies have assessed cognition in kidney transplant (TX) recipients, the neuropsychological presentation of this population is not yet clear. Kidney transplantation typically leads to improvement of metabolic factors associated with chronic kidney disease (CKD). However, comorbid diseases independently linked with cognitive compromise often persist, and for this reason, cognitive difficulties may still be present following transplantation. Methods. In this cross-sectional study, we assessed cognition in 42 kidney TX recipients, 45 outpatients with pre-dialysis CKD and 49 healthy controls using measures of verbal learning and memory and executive functioning. Results. Findings indicated that TX and CKD patients demonstrated significantly worse verbal learning and memory in comparison to controls. While both CKD and TX patients exhibited significantly worse performance than controls on a response inhibition measure, only CKD patients performed significantly worse on a set-shifting task. Conclusions. Results suggest that, in comparison to controls, verbal memory and executive functioning skills are worse in both CKD and TX patients. Further research is needed to determine the etiology and extent of cognitive compromise, as well as to assess the clinical implications of these findings.