title: Event-related potentials and white matter lesions in bipolar disorder.
abstract: OBJECTIVE
  To investigate neurophysiological parameters which possibly distinguish subtypes I and II of patients with a bipolar disorder, and contrast the findings with observations from a group of schizophrenic patients and a group of healthy controls.
  
  
  METHODS
  Sixty-six volunteers underwent a MRI scan to determine the number and location of white matter lesions (WSL). A electrophysiological registration was made while all volunteers performed a auditory 'oddball' task, and the amplitude of the resulting P300 wave was compared.
  
  
  RESULTS
  Earlier reports of higher numbers of WSL in bipolar disorder were not replicated in this study. Subtypes I and II showed a different P300 amplitude and subtype I resembled the results of the schizophrenia group.
  
  
  CONCLUSIONS
  Bipolar patients in remission have a functional brain disorder that is expressed by a change in physiological response to external stimuli.
authors.affiliation: 1Universiteit Maastricht, Department of Neuropsychology.
authors.forename: E F P M
authors.initials: EF
authors.lastname: Vuurman
authors.affiliation: 2Academisch Ziekenhuis Maastricht, Department of Psychiatry.
authors.forename: A
authors.initials: A
authors.lastname: Honig
authors.affiliation: 2Academisch Ziekenhuis Maastricht, Department of Psychiatry.
authors.forename: T H
authors.initials: TH
authors.lastname: Lamers
authors.affiliation: 1Universiteit Maastricht, Department of Neuropsychology.
authors.forename: J
authors.initials: J
authors.lastname: Wiersma
authors.affiliation: 1Universiteit Maastricht, Department of Neuropsychology.
authors.forename: L
authors.initials: L
authors.lastname: Krabbendam
authors.affiliation: 3Academisch Ziekenhuis Maastricht, Department of Radiology.
authors.forename: P A M
authors.initials: PA
authors.lastname: Hofman
authors.affiliation: 4Academisch Ziekenhuis Utrecht, Department of Psychiatry.
authors.forename: W A
authors.initials: WA
authors.lastname: Nolen
authors.affiliation: 1Universiteit Maastricht, Department of Neuropsychology.
authors.forename: J
authors.initials: J
authors.lastname: Jolles