title: Comparison of visual evoked potentials in patients with psychogenic visual disturbance and malingering.
abstract: OBJECTIVE
  To verify the efficiency and objectivity of the pattern visual evoked potential (VEP) for organic disorders of the cortical visual system.
  
  
  METHODS
  This retrospective study evaluated VEP in 19 patients diagnosed with psychogenic visual disturbance, 7 patients with malingering, and 37 age-matched normal volunteers. Transient (3 reversals per second) and steady-state (12 reversals per second) pattern VEPs for check sizes 15' and 30', with a contrast of 80%, were recorded.
  
  
  RESULTS
  The amplitudes of both transient and steady-state pattern VEPs were significantly increased in patients with psychogenic visual disturbance, while patients with malingering had significantly lower amplitudes. P100 peak latency was prolonged in both groups of patients.
  
  
  CONCLUSIONS
  Monitoring of patients' fixation on the stimulus showed those with psychogenic visual disturbance fixated well on the stimulus, while those with malingering did not. This finding produced a VEP amplitude reduction in patients with malingering. The reason for the VEP amplitude in patients with psychogenic visual disturbance is unclear.
authors.affiliation: Department of Ophthalmology, Chiba University School of Medicine, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Saitoh
authors.forename: E
authors.initials: E
authors.lastname: Adachi-Usami
authors.forename: A
authors.initials: A
authors.lastname: Mizota
authors.forename: N
authors.initials: N
authors.lastname: Fujimoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008306:Malingering / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D008875:Middle Aged; D011602:Psychophysiologic Disorders / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D014792:Visual Acuity; D014794:Visual Fields