Videonystagmography

Videonystagmography (VNG) is a type of testing used to assess vestibular and central nervous system function through the use of eye movement tracking, specifically evaluating nystagmus. The older version of technology used to perform these tests, known as electronystagmography (ENG), leverages electrophysiological signals. There is a battery of tests which can be performed using this technology and testing, typically performed by an audiologist. These tests can be diagnostic in nature or used to monitor rehabilitation. The testing typically takes place in a dark or dimmed room with the patient laying or sitting, depending on the test, on a table or chair that can lean back to a flat position. The patient wears goggles containing a camera that tracks the pupils using infrared imaging; the video eye-tracking system records and sends pupil movement tracings to a computer typically with VNG analysis software. The goggles may also have a cover in order to deny vision for some tests while still recording eye movement. There may be some kind of screen or light bar used to present visual stimuli, though providers may use other kinds of visual stimuli for portions of the testing. VNG can determine whether dizziness is caused by inner ear disease, particularly benign paroxysmal positional vertigo (BPPV), as opposed to some other cause such as low blood pressure or anxiety.

VNG testing is made up of several components.