title: Critical flicker frequency fails to disclose brain dysfunction in patients with primary biliary cirrhosis.
abstract: BACKGROUND
  Recent studies suggest that stage-independent symptoms of primary biliary cirrhosis (PBC) such as chronic fatigue are a consequence of structural and functional abnormalities of the brain. Critical flicker frequency (CFF) is a psychophysiological modality analysing function of cerebral cortex.
  
  
  OBJECTIVE
  To analyse the usefulness of CFF in detection of brain dysfunction in patients with PBC.
  
  
  METHODS
  Fifty-one (37 non-cirrhotic/14 cirrhotic) patients with PBC were included. Control group consisted of 31 matched healthy individuals. Fatigue and health-related quality of life (HRQoL) were assessed using Fatigue Impact Scale (FIS) and questionnaire PBC-40. CFF was analysed with HEPAtonorm Analyzer(®).
  
  
  RESULTS
  When compared to healthy controls all patients with PBC showed significantly impaired HRQoL in majority of PBC-40 domains and increased fatigue level in physical domain of FIS. No differences in HRQoL and PBC-40 domains were seen, when patients with and without cirrhosis where compared. CFF analysis showed no difference between healthy controls and patients with PBC. CFF did not correlate with PBC-40 and FIS domains.
  
  
  CONCLUSIONS
  CFF fails to determine brain dysfunction in non-encephalopatic patients with PBC, suggesting that functional efficiency of their cerebral cortex remains unaffected and other central mechanisms are responsible for chronic fatigue in these patients.
authors.affiliation: Liver Unit, Pomeranian Medical School, Szczecin, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Wunsch
authors.forename: Michał
authors.initials: M
authors.lastname: Post
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Gutkowski
authors.forename: Wojciech
authors.initials: W
authors.lastname: Marlicz
authors.forename: Barbara
authors.initials: B
authors.lastname: Szymanik
authors.forename: Marek
authors.initials: M
authors.lastname: Hartleb
authors.forename: Piotr
authors.initials: P
authors.lastname: Milkiewicz
mesh_terms: D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000473:pathology*; D002908:Chronic Disease; D005221:Fatigue / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006801:Humans; D008105:Liver Cirrhosis, Biliary / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011603:Psychophysiology; D011788:Quality of Life; D012720:Severity of Illness Index; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires