title: Auditory event-related cerebral potentials (P300) in hepatic encephalopathy--topographic distribution and correlation with clinical and psychometric assessment.
abstract: OBJECTIVE
  Early cognitive disturbances in patients with cirrhosis (Ci) are difficult to assess. Therefore, we evaluated the role of topographic auditory evoked cerebral potentials (P300-EP).
  
  
  METHODS
  Prospective longitudinal study.
  
  
  METHODS
  Tertiary clinical care institution.
  
  
  METHODS
  45 patients with cirrhosis were compared to 22 healthy subjects.
  
  
  METHODS
  Hepatic Encephalopathy (HE) was assessed using the clinical grading, standardized psychometric tests, and auditory evoked P300-EP by multichannel EEG recordings.
  
  
  RESULTS
  In the patients, the mean P300 peak latency was significantly increased (386.7 +/- 26.7 versus 318.6 +/- 22.2 ms in controls, p < 0.00001). Even in patients with cirrhosis but no HE (n = 18) the P300 peak latency was abnormally prolonged (> 384 ms) in 8 cases (44%). In addition, P180 peak latency was significantly longer in patients with liver cirrhosis as compared to controls (p = 0.021). The maximal P300 amplitude was significantly lowered in patients with liver cirrhosis in the frontocentral and central cortical regions (FZ: p < 0.008; Cz: p < 0.04). Liver function and etiology of liver disease were not related to the increased peak latencies of the P300 and P180 peaks.
  
  
  CONCLUSIONS
  P300-EP is a sensitive measure to detect functional cognitive impairment in cirrhotic patients with subclinical HE and clinically apparent HE. Typical changes include latency prolongation and decreased central peak amplitude. Some 40% of patients with no clinical evidence of HE and normal psychometric tests show abnormal results during P300 testing, which is likely to reflect early impairment of cognitive function. Auditory evoked P300 potentials are more sensitive than psychometric testing alone.
authors.affiliation: Department of Internal Medicine I, University of Regensburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Hollerbach
authors.forename: F
authors.initials: F
authors.lastname: Kullmann
authors.forename: R
authors.initials: R
authors.lastname: Fründ
authors.forename: G
authors.initials: G
authors.lastname: Lock
authors.forename: A
authors.initials: A
authors.lastname: Geissler
authors.forename: J
authors.initials: J
authors.lastname: Schölmerich
authors.forename: A
authors.initials: A
authors.lastname: Holstege
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005260:Female; D006501:Hepatic Encephalopathy / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000379:methods*; D012680:Sensitivity and Specificity