Electrodes, Neurologic, Evoked Potential, Visual, Electronystagmography
Definition : Neurologic electrodes designed to detect and measure bioelectrical signals generated by eye movement (electronystagmography, ENG) as the result of cold and/or warm fluids entering the ears. These devices typically are skin electrodes that are placed above, below, and on each side of the eyes. As the eye moves, the electrodes detect the electrical signal caused by eye movement and relay it to one or more channels, where it is amplified. Electrodes intended for conventional three-point configuration ENG (i.e., one electrode on each eye and one on the forehead) are available; they are used to measure the potential from both eyes simultaneously. Electrodes used in a configuration requiring two channels for each eye that are intended to perform electronystagmography measuring eye movement in any direction, not just vertical and horizontal, known as vector-electronystagmography, are also available. The electrodes are placed equidistant to the center of each eye at right angles on the vertical and horizontal axes, resulting in less error than with the three-point configuration. ENG electrodes are used to assess the functioning of the brain's acoustic and oculomotor nerves; they can be used to determine the causes of visual problems, vertigo, and/or dizziness. The electrodes are also used to detect and measure eye movements resulting from involuntary, periodic and rapid movement of the eyeballs (i.e., nystagmus) without the application of any external stimuli.
Entry Terms : "Electrodes, Electronystagmographic"
UMDC code : 11442