Format

Send to:

Choose Destination
See comment in PubMed Commons below
Clin Neurophysiol. 2014 Feb;125(2):287-97. doi: 10.1016/j.clinph.2013.08.004. Epub 2013 Sep 10.

Insight into the relationship between brain/behavioral speed and variability in patients with minimal hepatic encephalopathy.

Author information

  • 1Department of Medicine, University of Padua, Italy; C.I.R.M.A.ME.C., University of Padua, Italy; IRCCS San Camillo, Lido di Venice, Italy. Electronic address: sami.schiff@unipd.it.
  • 2Department of Information Engineering, University of Padua, Italy.
  • 3Department of General Psychology, University of Padua, Italy.
  • 4Department of Medicine, University of Padua, Italy; C.I.R.M.A.ME.C., University of Padua, Italy.
  • 5IRCCS San Camillo, Lido di Venice, Italy.
  • 6C.I.R.M.A.ME.C., University of Padua, Italy; Department of Information Engineering, University of Padua, Italy.
  • 7C.I.R.M.A.ME.C., University of Padua, Italy; Department of General Psychology, University of Padua, Italy.

Abstract

OBJECTIVE:

Intra-individual variability (IIV) of response reaction times (RTs) and psychomotor slowing were proposed as markers of brain dysfunction in patients with minimal hepatic encephalopathy (MHE), a subclinical disorder of the central nervous system frequently detectable in patients with liver cirrhosis. However, behavioral measures alone do not enable investigations into the neural correlates of these phenomena. The aim of this study was to investigate the electrophysiological correlates of psychomotor slowing and increased IIV of RTs in patients with MHE.

METHODS:

Event-related potentials (ERPs), evoked by a stimulus-response (S-R) conflict task, were recorded from a sample of patients with liver cirrhosis, with and without MHE, and a group of healthy controls. A recently presented Bayesian approach was used to estimate single-trial P300 parameters.

RESULTS:

Patients with MHE, with both psychomotor slowing and higher IIV of RTs, showed higher P300 latency jittering and lower single-trial P300 amplitude compared to healthy controls. In healthy controls, distribution analysis revealed that single-trial P300 latency increased and amplitude decreased as RTs became longer; however, in patients with MHE the linkage between P300 and RTs was weaker or even absent.

CONCLUSIONS:

These findings suggest that in patients with MHE, the loss of the relationship between P300 parameters and RTs is related to both higher IIV of RTs and psychomotor slowing.

SIGNIFICANCE:

This study highlights the utility of investigating the relationship between single-trial ERPs parameters along with RT distributions to explore brain functioning in normal or pathological conditions.

Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

KEYWORDS:

Intra-individual variability of RTs; Minimal hepatic encephalopathy; Simon task; Single-trial P300

PMID:
24035204
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk