title: Clinical predictors of individual cognitive fluctuations in patients undergoing hemodialysis.
abstract: BACKGROUND
  Cognitive impairment in hemodialysis (HD) patients is frequent and mediated by several factors. It is unclear which patients are more susceptible to cognitive variations around the dialysis cycle and which clinical factors may play a mediator role. We aimed to answer these issues by investigating intraindividual changes within the dialysis cycle.
  
  
  METHODS
  Cross-sectional observational study with repeated measures.
  
  
  METHODS
  47 HD patients and 40 controls without kidney disease, both without history of neurologic disease.
  
  
  METHODS
  Dialysis vintage, disease duration, vascular risk factors, comorbidity index score, intradialytic weight change, frequency of hypotensive episodes, and biochemical levels (hemoglobin, leukocytes, urea, creatinine, sodium, and potassium). Covariates included demographics (age, education, and sex).
  
  
  METHODS
  Significant individual deterioration in attention and executive functions (phasic and intrinsic alertness, Stroop test, and Trail Making Test) after dialysis, as measured by a regression-based reliable change method. Regression models were used to identify clinical predictors of individual cognitive decline after dialysis.
  
  
  RESULTS
  After dialysis, patients primarily showed prolonged reaction times and psychomotor slowing. However, individual-based analyses revealed that fluctuations in attention and executive functions were present in only a minority of patients. Significant individual fluctuations on particular attention and executive tasks were associated moderately with intradialytic hypotensive episodes, as well as with psychoactive medication, and were predicted weakly by blood leukocyte count, sodium level, dialysis vintage, and volume.
  
  
  CONCLUSIONS
  Small sample size; patient group younger and healthier than the overall HD population, limiting generalizability.
  
  
  CONCLUSIONS
  Only a minority of patients exhibit significant individual cognitive fluctuations, predominantly showing deterioration after dialysis in attention and executive functions. Susceptibility to such fluctuations was predicted in part by both HD-dependent and -independent factors.
authors.affiliation: Department of Neurology, Rheinisch-Westfaelische Technische Hochschule (RWTH) Aachen University Hospital, Aachen, Germany; Jülich Aachen Research Alliance (JARA)-Translational Brain Medicine, Aachen and Jülich, Germany.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Costa
authors.affiliation: Department of Neurology, Rheinisch-Westfaelische Technische Hochschule (RWTH) Aachen University Hospital, Aachen, Germany; Jülich Aachen Research Alliance (JARA)-Translational Brain Medicine, Aachen and Jülich, Germany.
authors.forename: Frances E
authors.initials: FE
authors.lastname: Tiffin-Richards
authors.affiliation: KfH Kuratorium für Dialyse und Nierentransplantation e.V., Stolberg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Holschbach
authors.affiliation: Department of Internal Medicine, St.-Antonius-Hospital Eschweiler, Eschweiler, Germany.
authors.forename: Rolf D
authors.initials: RD
authors.lastname: Frank
authors.affiliation: Dialysezentrum Aachen Praxis und Dialyse, Aachen, Germany.
authors.forename: Athina
authors.initials: A
authors.lastname: Vassiliadou
authors.affiliation: Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany.
authors.forename: Thilo
authors.initials: T
authors.lastname: Krüger
authors.affiliation: Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany; Bayer Pharma AG, Global Drug Development, Kidney Diseases Research, Wuppertal, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Eitner
authors.affiliation: Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany; Department of Internal Medicine, Dresden-Friedreichstadt Hospital, Dresden, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Gross
authors.affiliation: Department of Neurology, Rheinisch-Westfaelische Technische Hochschule (RWTH) Aachen University Hospital, Aachen, Germany; Jülich Aachen Research Alliance (JARA)-Translational Brain Medicine, Aachen and Jülich, Germany; Dialysezentrum Aachen Praxis und Dialyse, Aachen, Germany.
authors.forename: Nadim J
authors.initials: NJ
authors.lastname: Shah
authors.affiliation: Department of Neurology, Rheinisch-Westfaelische Technische Hochschule (RWTH) Aachen University Hospital, Aachen, Germany; Jülich Aachen Research Alliance (JARA)-Translational Brain Medicine, Aachen and Jülich, Germany.
authors.forename: Jörg B
authors.initials: JB
authors.lastname: Schulz
authors.affiliation: Jülich Aachen Research Alliance (JARA)-Translational Brain Medicine, Aachen and Jülich, Germany; Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Floege
authors.affiliation: Department of Neurology, Rheinisch-Westfaelische Technische Hochschule (RWTH) Aachen University Hospital, Aachen, Germany; Jülich Aachen Research Alliance (JARA)-Translational Brain Medicine, Aachen and Jülich, Germany; Institute of Neuroscience and Medicine (INM-4), Research Center Jülich GmbH, Jülich, Germany. Electronic address: kreetz@ukaachen.de.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Reetz
mesh_terms: D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology*; D003430:Cross-Sectional Studies; D056344:Executive Function; D005260:Female; D006801:Humans; D007022:Hypotension; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D006435:Renal Dialysis / Q000009:adverse effects* / Q000523:psychology
keywords: Chronic kidney disease; attention; cognition; cognitive impairment; executive function; fluctuations; hemodialysis; neuropsychological assessment; psychomotor speed; reliable change; variations in cognitive function