Videonystagmography (VNG) is an examination of the functioning of the balance system, in particular the functioning of the vestibular system in the inner ear. The functioning of the balance system is examined via the eyes.
Videonystagmography is used in patients who suffer from dizziness. On the basis of this examination, the doctor can determine whether the vestibular system is working well and what the cause of the symptoms is.
When a person is dizzy, this manifests itself in rapid eye movements, which can be measured during the examination. These eye movements are called nystagmus.
In the examination room, video glasses are placed onto the head of the patient, which register the eye movements using an infrared camera. During the examination, several tests are carried out. The patient should follow lights with the eyes. He or she takes a seat in a swivel chair. Position tests are performed and water is sprayed into the ears.
The examination is harmless. Although the patient may get dizzy in some test items, this usually disappears soon after each test. Seldom, nausea occurs. The examination takes an average of forty-five minutes, but may also last longer.