Vestibular & Electrophysiology Testing

At Gallaudet University Dizziness and Balance Center, dizzy patients can receive the following evaluations.


  • VNG and ENG


Videonystagmography (VNG) and electronystagmography (ENG) are essentially the same test. With the VNG, you will wear goggles with infrared cameras that will track your eye movements. In some cases, these video goggles cannot be used, so the patches that will detect your eye movements will be placed around your eyes - this is called the ENG.


VNG (and ENG) is considered the 'gold standard' of vestibular assessment. There are 3 parts to this test. During the first part, you will be asked to follow moving and non-moving dots. This is testing your ability to move your eyes voluntarily. During the second part, you will be placed in different head and body positions, in order to evaluate whether certain head and body positions cause dizziness. During the final part of the test, warm and cool air will be used to change the temperature in the inner ear vestibular organs, specifically the horizontal semicircular canals. This temperature change simulates slow head turns, and allows us to evaluate the sensitivity of the horizontal semicircular canals.


This test takes 60 to 90 minutes.


  • VEMP


Vestibular-evoked myogenic potential (VEMP) is another test of vestibular functions. It primarily evaluates the health of another set of vestibular organs called the saccule, the gravity sensing organs. During this test, repetitive sounds are delivered to the inner ear through the earphones, causing pressure fluctuations in the inner ear. The saccule detects the pressure fluctuation and sends the signal through the brainstem to the spinal cord, then to the various muscles of the body. We measure the responses from the neck muscles - therefore, you will be asked to turn your head and contract the neck muscles for about 30 to 60 seconds at a time.


This test takes anywhere between 15 to 45 minutes.


  • Hearing Evaluation


Because the inner ear is made to detect both the sounds (hearing functions) and head movements (vestibular functions), certain pathologies and syndromes cause both dizziness and changes in hearing. Because of that, it is essential that a complete hearing evaluation be done as part of the dizziness and balance function assessment.


This test takes 60 to 90 minutes.


  • ABR


Auditory brainstem response (ABR) tests the function of the auditory (hearing) pathway from the inner ear up to the brainstem. Because the vestibular nerve and the hearing nerve share the same tract traveling up to the brainstem, problems with dizziness can be related to lesions of the hearing nerve. During this test, patches of electrodes will be placed on your head and the ears. Repetitive noises will be delivered to your ears through ear phones, and you will be asked to lie very quietly and relaxed. The more relaxed you are, the faster the test will be completed, and you are even encouraged to take a nap during this test.


This test takes 20 to 45 minutes.