videonystagmografi

Videonystagmography (VNG) is a diagnostic procedure that records eye movements to assess vestibular and central nervous system function. The system uses infrared video to track pupil motion and corneal reflections, enabling quantitative analysis of nystagmus and other ocular motor responses. VNG commonly replaces older electro-oculography (ENG) in clinical practice.

During the examination, the patient sits or lies with the head stabilized. After calibration, a series of tests are performed: spontaneous nystagmus with the head in a neutral position, gaze-evoked nystagmus, pursuit (tracking) and saccade testing to assess central ocular motor pathways, and optokinetic nystagmus. Positional and provocative maneuvers, such as Dix-Hallpike or roll tests, may be conducted to elicit nystagmus associated with benign paroxysmal positional vertigo. Caloric testing involves irrigation or perfusion of the ears with warm and cold air or water to stimulate one horizontal semicircular canal at a time, with the resulting slow-phase velocity recorded for each ear.

Interpretation focuses on the presence, direction, intensity, and adaptation of nystagmus, helping distinguish peripheral from central vestibular disorders. VNG aids in diagnosing conditions such as Menière’s disease, vestibular neuritis, benign paroxysmal positional vertigo, bilateral vestibulopathy, and various central lesions. It is also used to monitor recovery and guide rehabilitation.

Advantages include non-invasiveness and comprehensive ocular motor assessment; limitations include potential discomfort from caloric testing, susceptibility to artifacts, and limited assessment of high-frequency vestibulo-ocular reflexes. Results should be integrated with clinical findings and other tests.