title: Diagnostic and prognostic values of critical flicker frequency determination as new diagnostic tool for objective HE evaluation in patients undergoing TIPS implantation.
abstract: OBJECTIVE
  The diagnostic and prognostic value of critical flicker frequency (CFF) analysis for assessment of severity and dynamics of hepatic encephalopathy (HE) was studied before and after implantation of a transjugular intrahepatic portosystemic shunt (TIPS).
  
  
  METHODS
  Sixty-three cirrhotic patients were retrospectively analyzed for the consequences of TIPS implantation. Thirty-one cirrhotic patients without TIPS implantation served as age-matched, sex-matched, Child-Pugh-matched controls. CFF and computer psychometric tests as objective test parameters of HE-severity were evaluated for analysis of visual discrimination ability, general arousal and cognitive function. Kaplan-Meier method and Cox proportional hazards regression model were used for analysis of prognostic significances.
  
  
  RESULTS
  In the control group, HE-severity was stable during the observation period (442+/-428 days) with minimal changes in CFF (-0.1+/-1.9 Hz). In the intervention group, TIPS implantation had no effect on HE-severity in 44% of the patients and CFF shifted by only 0.01+/-1.5 Hz. Thirty-five and 21% of the patients experienced an aggravation or improvement of HE after TIPS implantation, respectively. In HE improvers CFF increased by 3.3+/-2.3 Hz and decreased by 3.5+/-1.5 Hz in those experiencing an aggravation of HE-severity. Univariate analysis showed that overall survival in the study population inversely correlated with HE-severity and serum alkaline phosphatase activity and positively correlated with serum sodium, albumin and CFF. Serum albumin, alkaline phosphatase levels and CFF were independent predictors of survival in a multivariate Cox regression analysis.
  
  
  CONCLUSIONS
  The data show that pre-TIPS HE does not predict post-TIPS encephalopathy. Otherwise, CFF can reliably pick up the evolution of HE-severity after TIPS implantation. Low pre-TIPS CFF is indicative for a poor prognosis and may help to identify transplant candidates without delay.
authors.affiliation: Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany. kircheis@med.uni-duesseldorf.de
authors.forename: Gerald
authors.initials: G
authors.lastname: Kircheis
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Bode
authors.forename: Norbert
authors.initials: N
authors.lastname: Hilger
authors.forename: Thomas
authors.initials: T
authors.lastname: Kramer
authors.forename: Alfons
authors.initials: A
authors.lastname: Schnitzler
authors.forename: Dieter
authors.initials: D
authors.lastname: Häussinger
mesh_terms: D000328:Adult; D000368:Aged; D004812:Epidemiologic Methods; D005260:Female; D005425:Flicker Fusion; D006501:Hepatic Encephalopathy / Q000175:diagnosis* / Q000209:etiology / Q000523:psychology; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D019168:Portasystemic Shunt, Transjugular Intrahepatic / Q000009:adverse effects*; D011379:Prognosis; D011594:Psychometrics