Dizziness & Vertigo Evaluations

Vertigo, dizziness, and balance problems can be life-altering. For many people, it can affect their ability to do even the simplest daily tasks. If you are experiencing vertigo or balance issues, your doctor may want to refer you for a videonystagmography (VNG) balance evaluation.

What is a videonystagmography balance evaluation?

A VNG is a series of tests that evaluate the health of your vestibular (balance portion of inner ear) and your central motor function. VNG testing can help to uncover the root cause of your vertigo, dizziness or balance issues, and allows your doctor or hearing specialist to treat it appropriately and effectively.

What tests will be performed?

VNG testing consists of a variety of tests to uncover the root cause of your symptoms:

Video Head-Impulse Test (VHIT)

VHIT evaluates the function of all 6 semicircular canals, It tests the vestibulo-occular reflex (VOR) at higher frequencies (the Caloric’s only test ultra-low frequency). The identification of mid to high frequency active or uncompensated vestibular disorder is of critical importance to an individual’s safety and ability to return to work or daily activities.

vestibular evoked myogenic potentials (VEMPs)

The VEMP investigates otolith and vestibular nerve function. Dysfunction is characterized by feeling similar to being on a boat or an elevator. It may be a spinning sensation when people say that they are dizzy. The VEMP is evoked in response to high-level acoustic stimuli. The responses are mediated by the vestibular system.  Patients with complaints of sound-evoked vestibular symptoms such as Tullio phenomenon or superior canal dehiscence (SCD) can be assessed using VEMP. We can assess the saccule and the inferior portion of the vestibular nerve for different vestibular pathologies like Ménière’s or vestibular neuritis. We can also assess the utricle and the superior portion of the vestibular nerves. We are going beyond the semicircular canals in this case.

Ocular mobility

This test checks for your ability to follow visual targets, such as a moving light on a bar. You will attempt to follow targets with your eyes while an object is jumping, moving slowly, or standing still. The inability to track objects properly could indicate central or neurological problems or possibly an issue with the vestibular system connecting to the brain. Recording and evaluating eye movements is helpful because visual-motor neural pathways are connected to the vestibular or balance system of the inner ear.

Optokinetic nystagmus

This test also checks for your ability to follow visual targets. During this test, you will watch a  image that is continuously moving and will be asked to follow the movements. Similarly, this test will give clues to possible central or neurological problems or problems with the vestibular system.

Positional nystagmus

This test will help give an idea of the health of your inner ear system. You will be asked to move your head and body into different positions, allowing the hearing care professional to check for inappropriate eye movements in each position.

Caloric testing

This test can help determine if you have vestibular weakness in one or both ears by checking to see if your vestibular system responds properly to stimulus. Your eyes will be monitored while your inner ears are stimulated (one at a time) with warm or cold air or water

Preparing for VNG testing

Because of the nature of the tests, there are some preparations you will need to make before your evaluation. Our staff will provide you with clear instructions on how to prepare for your examination. For example, we may ask you to discontinue certain medications, not to consume any alcoholic beverages or caffeinated drinks at least 48 hours before the tests, to remove contact lenses or eyeglasses or to fast for a few hours prior to testing. The exact instructions may vary from patient to patient. If you have any questions about your instructions or how to prepare for the test, ask your hearing health professional.

The entire VNG evaluation typically lasts about 90 minutes and can cause some dizziness. This dizziness usually subsides within a short period of time. It is advised that you bring someone with you who can drive you home afterward if you are unable to drive or do not feel well after the tests.