title: Differential impairment of psychomotor efficiency and processing speed in patients with chronic kidney disease.
abstract: BACKGROUND
  Cognitive impairment has been documented in patients with chronic kidney disease. In a recent paper, improvements in cognitive function were seen in hemodialysis (HD) patients switched from conventional HD to nocturnal HD, in two of three domains of cognitive function. Based on these findings, we hypothesized that functional decline may occur differentially in some domains more than others.
  
  
  METHODS
  Using a cross-sectional study design, patients optimized on medical treatment at a predialysis clinic were tested using a battery of neuropsychological (NP) tests measuring three domains of cognitive functioning-attention & working memory skills; psychomotor efficiency & processing speed; and learning efficiency. Clinical subjective symptoms for cognitive functioning and depression were measured using the Patient's Assessment of Own Functioning (PAOF) inventory and the Beck Depression Inventory (BDI).
  
  
  RESULTS
  One hundred and three patients aged 64.6+/-12.4 years were recruited. Of these, 40% were diabetic, with a mean Charlson comorbidity score of 4.4+/-2.1. Depression (defined as >16 on the BDI score) was seen in 11 patients. After adjustment for comorbid diseases, hemoglobin, the use of neurodepressor medication, and parathyroid hormone (PTH) values, renal function was negatively correlated with psychomotor efficiency & processing speed, but not with attention & working memory or learning efficiency scores.
  
  
  CONCLUSIONS
  Chronic kidney disease is associated with a decline in psychomotor efficiency & processing speed, but not with attention & working memory or learning efficiency.
authors.affiliation: Department of Medicine, University Health Network, 8N-857, 200 Elizabeth St., Toronto, ON, Canada M5G 2C4. Vanita.Jassal@uhn.on.ca
authors.forename: Sarbjit V
authors.initials: SV
authors.lastname: Jassal
authors.forename: Janet
authors.initials: J
authors.lastname: Roscoe
authors.forename: Denise
authors.initials: D
authors.lastname: LeBlanc
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Devins
authors.forename: Sean
authors.initials: S
authors.lastname: Rourke
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D003072:Cognition Disorders / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology*; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*