Videonystagmography

VNG, recording eye movements to assess the balance system

Overview

Videonystagmography uses infrared cameras in goggles to record eye movements, because the vestibular system and the eyes are tightly linked through the vestibulo ocular reflex. The test battery typically examines gaze stability, tracking and saccadic eye movements, positional responses, and caloric testing, in which warm and cool air or water stimulates each ear in turn to compare their responses. Results help distinguish inner ear problems from central nervous system causes and show whether one side is weaker. It replaced the older electronystagmography, which measured eye movements with skin electrodes.