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Ilie Cretu, Solange Milazzo, Pierre Betermiez, Michel Petitjean; Visual evoked potentials (VEPs) to lateralized stimuli to measure the interhemispheric transfer time (IHTT). Invest. Ophthalmol. Vis. Sci. 2014;55(13):350.
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© ARVO (1962-2015); The Authors (2016-present)
To evaluate in a population of normal subjects the VEPs to lateralized stimuli to measure the interhemispheric transfer time (IHTT), and methodological variability factors.
We recorded in 36 young right-handed women evoked responses of visual occipital regions right (O2) and left (O1) in response to visual stimulation achieved through a screen with checkerboards alternants either in open fields, or half-fields when the line of sight coincides with a central focus. The test is performed in monocular eye test is chosen by lot with balancing choices, not to have any effect of precession. The atmosphere is scotopic total. The reversal of checkerboard is carried out at a frequency of 1.7Hz. Depending on the distance, the size of the checkerboard is 1 °.Were recorded average of 100 traces for each lead, during two successive series.
The results are presented according to three factors analyzed: the eye, the conditions (reproducibility and effect number), the observer. For stimulation in the full field, there is no effect or observer eye for the latencies of waves N75 and P100, and no effects eye or averaging effect for the latency of the N135 wave. For the half-full stimulation, there is no eye effect, or observer reproducibility, but there is a half-full field effect in the left eye. For TTIH, there is no significant difference between half-full fields, or effect or observer reproducibility, but there is an effect eye. Linear regression was highly significant between the P100 and TTIH.
The VEPs to lateralized stimuli seem a good method to calculate the IHTT, with good reproducibility and a minimal observer-effect. Further work on patient disease would be interesting to screen for a prolonged IHTT in inflammatory demyelinating CNS.
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