videonystagmografiaan

Videonystagmografía (VNG) is a diagnostic procedure that records and analyzes involuntary eye movements, or nystagmus, to evaluate the vestibular system and central pathways involved in balance and gaze. The method uses infrared video to track eye movements while the patient performs a series of standardized tests, often in a clinic or hospital setting.

During the test, the patient wears lightweight goggles with an infrared camera. The system calibrates eye position to establish a baseline, then records eye movements as the patient looks in various directions, gazes at targets, or experiences controlled stimuli. The resulting data provide quantitative measures of nystagmus velocity, direction, and latency.

Common components include spontaneous nystagmus assessment, gaze-holding, and positional tests such as the Dix-Hallpike or other maneuvers; caloric testing using warm or cold air or water to stimulate the horizontal semicircular canals; and optokinetic stimulation. Some centers also use rotary chair testing.

Interpretation distinguishes peripheral from central pathologies based on nystagmus pattern, latency, fatigability, and response to caloric or rotational stimuli. Normal results do not exclude disease; results must be interpreted with clinical context. Limitations include patient cooperation, artifacts from blinking or poor calibration, and discomfort during caloric stimulation.

VNG is commonly part of a vestibular test battery performed by otolaryngologists or neurologists. It complements other assessments but is not a stand-alone diagnostic. Benefits include objective, quantitative data and wide applicability; contraindications are rare but may involve active ear infections or severe vertigo.