In the past, electronystagmography (ENG) was a commonly administered set of vestibular tests administered to patients experiencing dizziness. Today, however, the more advanced videonystagmography (VNG) is the preferred technology for this testing. VNG tests are used to examine a patient’s balance system, identify the cause of dizziness and determine whether the condition affects one ear (unilateral) or both ears (bilateral).

VNG testing is more consistent and accurate than the old ENG method, and it offers patients a much more comfortable experience.

4 Parts of VNG Testing

During your VNG tests, video goggles and infrared cameras will measure your eye movements during four different types of testing. The procedure typically takes less than an hour and a half to complete and is noninvasive and painless, though brief episodes of vertigo may occur. The four main parts of VNG testing are:

  1. Optokinetic Nystagmus—During this portion, you will be asked to watch a large, continuously moving object. Your VNG technician will look for any slowness or inaccuracies in your eye movement, which can indicate a problem with the path between your vestibular system and your brain as well as a central or neurological problem.
  2. Positional Nystagmus—This test requires your technician to move your head and body into different positions so that your eye movement can be observed in different orientations. This VNG test assesses your inner-ear system and the condition and flow of the fluid in its canals. It can also identify BPPV if physical examinations fail to do so.
  3. Caloric Testing—Your ears are each stimulated individually with warm and cool air during this VNG test. Your technician will monitor your eye movements during these stimulations to ensure they react, confirming the vestibular system is working. This is the test that allows your technician to determine whether your problem is unilateral or bilateral.
  4. Occular Mobility—Your technician will ask you to visually follow the movements of objects as they change positions smoothly, jump around suddenly and stay still throughout this testing process. Delayed eye movements and inconsistencies can indicate vestibular or neurological problems.