DOI
https://doi.org/10.25772/GD40-VS31
Defense Date
1990
Document Type
Thesis
Degree Name
Master of Science
Department
Anatomy & Neurobiology
First Advisor
Juan Astruc
Abstract
he use of evoked potentials to evaluate the functional integrity of neuronal pathways has become a useful and accepted practice in clinical medicine. The use of visual evoked potentials for assisting in the diagnosis of such diseases as optic neuritis and multiple sclerosis is also well recognized. However, the visual evoked potential, unlike the auditory evoked potentials, lacks a well defined electrophysiological to neuroanatomical correlation; especially that of a significant non-cortical component. Currently, visual evoked potentials rely principally on the measurement of a cortical (occipital) positive peak of activity at 100ms (P100), recorded with a single channel electrode system, to evaluate pathway integrity. In this study, visual evoked potentials were recorded using a three-channel, orthogonal co-ordinate system which we have designated "vector" visual evoked potentials (VVEP). This method allows the generated evoked response to be plotted on a three dimensional co-ordinate system with respect to time. Through the use of pattern reversal of a checkerboard pattern, in full and hemi retinal field stimulation, reproducible activity both prior to and afier the P100 wave was demonstrated. In particular, activity found at approximately 55ms is believed to be generated from the Lateral Geniculate Body. Furthermore, because this method summarizes the activity of the entire brain for a given time, as opposed to the single channel recording, a great deal of information about the entire visual pathway can be suggested. Finally, anatomical correlates to discrete activities identified by this method can be made.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
10-30-2017
Comments
Scanned, with permission from the author, from the original print version, which resides in University Archives.