title: Visual evoked potentials in guillain-barré syndrome.
abstract: OBJECTIVE
  Guillain-Barré syndrome (GBS) is an acute demyelinating polyneuropathy with various clinical features. Optic neuritis occurs in rare cases. In this study we determined the incidence and patterns of visual evoked potential (VEP) abnormality in GBS in association with ophthalmologic findings.
  
  
  METHODS
  Thirty-two patients with a diagnosis of GBS were included in the study. The correlation between pathologic VEPs and categories of neurologic deficit and electrophysiological findings were examined statistically.
  
  
  RESULTS
  The patients ranged in age from 19 to 77 years. Five cases (16%) had abnormal VEPs. All five of these patients exhibited increased P100 latency differences between the two eyes. Other abnormalities were prolonged p100 latency, increased interocular amplitude difference, and distorted p100 configuration. Pathologic signs on ophthalmologic examination were observed in 80% of patients with abnormal VEPs. VEP abnormality was never present in pure axonal forms. There was no significant correlation between pathologic VEP and cerebrospinal fluid protein level or categories of neurologic deficits.
  
  
  CONCLUSIONS
  Involvement of the optic pathways is not a frequent finding in GBS. When present it is always asymmetric and generally accompanied with pathologic findings on ophthalmologic examination. VEPs may be abnormal in different clinical variants of GBS, and especially in demyelinating forms.
authors.affiliation: Department of Neurology, Ondokuz Mayis University School of Medicine, Samsun, Turkey.
authors.forename: Levent
authors.initials: L
authors.lastname: Güngör
authors.forename: Inci
authors.initials: I
authors.lastname: Güngör
authors.forename: Hilal Eser
authors.initials: HE
authors.lastname: Oztürk
authors.forename: Musa Kazım
authors.initials: MK
authors.lastname: Onar