title: Does a patent foramen ovale influence cognitive function in dialysis patients?
abstract: BACKGROUND
  Patients with chronic kidney disease on dialysis treatment have poorer cognitive function than age- and sex-matched controls. One proposed mechanism is cerebral microembolisation due to material from the dialysis circuit crossing a patent foramen ovale (PFO).
  
  
  METHODS
  Cognitive testing was carried out in haemodialysis (HD) patients and peritoneal dialysis (PD) patients. Transthoracic echocardiography was used to identify PFO. Follow-up testing 1 year later enabled comparison of cognitive decline between patients with and without a PFO, and between those undergoing different dialysis modalities.
  
  
  RESULTS
  80 patients (aged 60.4 ± 15.0 years) were recruited (51 HD patients and 29 PD controls). A PFO was found in 21% of patients. 83% of dialysis patients suffered a decline in one or more cognitive function tests over 1 year. There was a significant difference in only one test between HD patients with or without a PFO. PD patients showed a more rapid cognitive decline than those on HD.
  
  
  CONCLUSIONS
  Cognitive decline in dialysis patients is rapid and affects most patients. The presence of a PFO made only subtle differences to the rates of cognitive decline during 1 year of follow-up. Patients with a PFO should not be prevented from considering HD because of concerns of cerebral decline due to microembolisation.
authors.affiliation: Clinical Investigations and Research Unit, Brighton and Sussex University Hospitals, Brighton, UK. sudhakargeorge@gmail.com
authors.forename: Sudhakar
authors.initials: S
authors.lastname: George
authors.forename: Stephen
authors.initials: S
authors.lastname: Holt
authors.forename: Nick
authors.initials: N
authors.lastname: Medford
authors.forename: David
authors.initials: D
authors.lastname: Hildick-Smith
mesh_terms: D015984:Causality; D003072:Cognition Disorders / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D054092:Foramen Ovale, Patent / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D020766:Intracranial Embolism / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000706:statistics & numerical data*; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology* / Q000534:rehabilitation*; D012307:Risk Factors; D014739:Victoria / Q000453:epidemiology