Vestibular Evaluation Testing

Stanford Ear Institute

   

Videonystagmography (VNG)

Videonystagmography (VNG) is a series of tests that evaluate different parts of the balance system, including those within the inner ear as well as those in the brain. During testing, the patient wears goggles equipped with eye-tracking cameras that record eye movements throughout testing. The patient is asked to complete a variety of tasks including watching a moving target on a TV screen and laying in different positions. Finally, warm or cool air is gently introduced into each ear while lying flat. This test is used to determine the strength of the vestibular response, for each ear separately. It is common to feel some dizziness during this last part of the test. However, dizziness generally subsides shortly after completion of testing.

Video Head Impulse (vHIT) Testing

The Video Head Impulse Test (vHIT) assesses function of the specific balance organs in the inner ear known as semicircular canals. These provide information about rotation to the brain. The patient wears eye-tracking goggles with a head-tracking motion sensor. During the test, the patient fixates on a stationary visual target while the examiner turns the patient’s head in different directions. These directions correspond to the different planes of the semicircular canals. The head and eye movements are recorded and analyzed.

Vestibular Evoked Myogenic Potentials (VEMPs)

Vestibular Evoked Myogenic Potential (VEMP) testing is used to determine function of the specific balance organs known as the saccule and utricle. These provide information about gravity and acceleration to the brain. Sticker electrodes are applied to the forehead, under the eyes, and on the neck. The patient listens to a tapping sound and either looks upwards with their eyes or lifts their head while laying down. During this task, the sticker electrodes measure a natural reflex from the eye and neck muscles. The presence or absence of these reflexes provides information about the vestibular system.

Rotary Chair

Rotary chair testing is an alternative method for investigating the peripheral balance system. The patient wears eye-tracking goggles while sitting in a chair that slowly rotates around. During testing, the patient’s eye movements are tracked and recorded.  The degree of eye movement provides information about the balance system.

Preparation Recommendations

  • Continue all regular medications (as-needed medications may be brought with you and used after the testing)
  • Avoid wearing make-up.
  • Wear casual comfortable clothing.
  • You may continue to wear your contact lenses or hearing aids during the exam. Eye-glasses may need to be removed temporarily.
  • Avoid large meals (you may eat small portions up to 2 hours before).
  • Bring someone with you to drive you home.