title: [Topographic distribution of visual evoked potentials in optic neuropathy].
abstract: BACKGROUND
  Digital treatment of electrical signals coming from the central nervous system on stimulation of the optic nerve path offers an objective method for evaluation of visual evoked potentials (VEP) shown graphically on a cerebral map.
  
  
  OBJECTIVE
  To evaluate the topographical distribution of VEP in cases of optic neuropathy adding this parameter to the usual parameters of latency and amplitude.
  
  
  METHODS
  We studied 35 patients with suspected optic neuropathy and normal findings on basic ophthalmological examination, in whom VEP and VEP mapping (VEPM) was done.
  
  
  RESULTS
  In 26% of the cases there was no response for evaluation with the usual VEP recording techniques, whilst in those with VEPM this percentage was reduced to 11.5%. In the other cases there was a potential with characteristic distribution in the occipital areas and a maximally positive dipole posteriorly.
  
  
  CONCLUSIONS
  VEPM is an objective method for evaluation of the visual pathway offering better discrimination than the usual VEP in more severe cases of neuropathy.
authors.affiliation: Servicio de Neurofisìología Clínica, Hospital Miguel Servet, Zaragoza, España.
authors.forename: M J
authors.initials: MJ
authors.lastname: Valiño
authors.forename: A
authors.initials: A
authors.lastname: Piñero
authors.forename: J
authors.initials: J
authors.lastname: Urriza
authors.forename: G R
authors.initials: GR
authors.lastname: Chopo
authors.forename: J R
authors.initials: JR
authors.lastname: Valdizán
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000703:Analog-Digital Conversion; D001931:Brain Mapping; D003389:Cranial Nerve Diseases / Q000503:physiopathology; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000503:physiopathology; D009900:Optic Nerve / Q000503:physiopathology*; D010775:Photic Stimulation; D011930:Reaction Time; D014786:Vision Disorders / Q000503:physiopathology
vernacular_title: Distribución topográfica del potencial evocado visual en la neuropatía óptica.