VNG testing with Christie Heubner, HH AudiologistThe eyes are the window to the ears.
 
Part of the function of the inner ear is to keep the brain informed about how the head is moving and where the head is with respect to gravity. The brain uses this information to make compensatory movements of the eyes to keep them fixed on what you are looking at. This is a reflex aptly called the “vestibulo-ocular reflex,” or VOR. Without the VOR, every time you move your head or walk around, the world would look like it is bouncing and blurry (picture what happens to the picture on a hand-held video camera when you walk around with it). By testing the VOR in certain ways, an assessment can be made about how the inner ears are working.

At the Dizziness Clinic there are two related types of tests for this that you may have in order to help us diagnose you. These include Video Occulography and Video Nystagmography.

Video Occulography consists of a pair of goggles that you wear to block your vision, and an infrared video camera that monitors and records one of your eyes. Dr. Eisen is likely to use this during a consultation. This method allows him to see eye movements that can not otherwise be seen.

Video Nystagmography (or VNG) is a battery of tests performed by the audiologist where eye movements are monitored in response to different movements of the head, motion of a light, or a puff of air in your ear canal. A sophisticated pair of goggles monitor and record both eyes during the testing. The VNG can be very helpful in diagnosing several of the problems associated with dizziness. The VNG test battery takes about an hour.

Vestibular Evoked Myogenic Potential (VEMP) Testing is a brief, non-invasive test that is usually used to assess people with dizziness. It complements the VNG testing and is often performed at the same time. While the VNG test evaluates the lateral semicircular canal and superior vestibular nerve, the VEMP test targets another branch of the vestibular (balance) system, called the saccule, and the inferior vestibular nerve.

During the procedure the patient lies down on her back and an electrode is attached to the skin of the neck. The patient must then raise her head, unsupported, which tenses the front neck muscles, while a sound stimulus is played in the ear. The test only takes a few minutes to perform and causes little or no discomfort. The VEMP test does not cause dizziness.

The VEMP helps us identify several specific causes of dizziness:
  1. Superior canal dehiscence. A thinning of the bone between the superior semicircular canal and the brain causes a dizzy sensation induced by loud noises.
  2. Vestibular nerve disorders, such as acoustic neuromas and vestibular neuritis.