When do asymmetrical full-field pattern reversal visual evoked potentials indicate visual pathway dysfunction in children?

Doc Ophthalmol. 2011 Feb;122(1):9-18. doi: 10.1007/s10633-010-9250-1. Epub 2010 Nov 3.

Abstract

Our study aimed to find out the association between full-field pattern reversal visual evoked potential (pVEP) transoccipital asymmetries and half-field pVEP transoccipital distributions in children. Over a six-month period, 46 patients (mean age: 9 years 9 months) had both monocular full-field and half-field pVEPs to test checks subtending 50 min of arc in a 35 degree full-field and 0-17.5 degree lateral half-field. Silver-silver chloride electrodes placed at Oz, O1 and O2 were referred to Fz. Monocular full-field data were categorised according to the degree of transoccipital asymmetry. Half-field data were measured and summated to see whether they explained any full-field asymmetry. In this cohort of 46 patients, eight (17%) patients had symmetrically distributed monocular full-field pVEPs for each eye. Four of these patients had normal half-field pVEP distributions for each eye, but the other four showed a half-field deficit in one or both eyes. Of the 38 patients with asymmetrically distributed full-field pVEPs in at least one eye, 17 (44%) patients showed a half-field deficit, 20 (53%) showed responsive, but symmetrically distributed half-field responses, and one patient (3%) showed typical half-field distributions. Half-field pVEPs can help explain full-field asymmetries and should be attempted in any child able to co-operate with testing and in whom visual pathway dysfunction is suspected.

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Cohort Studies
  • Evoked Potentials, Visual*
  • Female
  • Humans
  • Male
  • Occipital Lobe / physiopathology*
  • Photic Stimulation / methods*
  • Reaction Time
  • Retrospective Studies
  • Vision Disorders / physiopathology*
  • Vision, Monocular / physiology
  • Visual Fields*
  • Visual Pathways / physiopathology*