title: The impact of fatigue on cognitive functioning in patients with multiple sclerosis.
abstract: OBJECTIVE
  To study the impact of physical and mental fatigue on cognitive complaints and cognitive performance in patients with multiple sclerosis.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  An outpatient neurology clinic.
  
  
  METHODS
  Eighty patients diagnosed with clinically definite multiple sclerosis.
  
  
  METHODS
  The subscales physical and mental fatigue of the Multidimensional Fatigue Inventory; the Hospital Anxiety and Depression Scale and the Cognitive Failure Questionnaire. Cognitive performance was assessed by an extensive neuropsychological test battery, including several tasks requiring effortful information processing.
  
  
  RESULTS
  Both anxiety and depression and mental fatigue significantly contributed to cognitive complaints, explaining respectively about 9% and 39% of the total variance. The contribution of physical fatigue to cognitive complaints was not significant. Both physical and mental fatigue did not significantly contribute to cognitive performance in terms of mental speed, attention, memory and executive functioning.
  
  
  CONCLUSIONS
  To refine interventions for those patients with cognitive complaints, we advise adding measurements of anxiety, depression and fatigue to their neuropsychological assessment. Fatigue permits extensive neuropsychological assessment, which is needed to detect cognitive impairment in multiple sclerosis.
authors.affiliation: Department of Medical Psychology and Psychiatry, Orbis Medical Centre, Sittard, School for Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands. y.bol@maastrichtuniversity.nl
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Bol
authors.forename: Annelien A
authors.initials: AA
authors.lastname: Duits
authors.forename: Raymond M M
authors.initials: RM
authors.lastname: Hupperts
authors.forename: Inge
authors.initials: I
authors.lastname: Verlinden
authors.forename: Frans R J
authors.initials: FR
authors.lastname: Verhey
mesh_terms: D000328:Adult; D001007:Anxiety / Q000150:complications; D003072:Cognition Disorders / Q000209:etiology*; D003430:Cross-Sectional Studies; D003863:Depression / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D005222:Mental Fatigue / Q000523:psychology*; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000523:psychology*; D009483:Neuropsychological Tests; D010044:Outpatient Clinics, Hospital; D055815:Young Adult