Dizziness & Balance Testing
Our eyes are a window into our vestibular system and being able to record how they react to various stimuli can provide your care team with valuable information. Audiologists at the Jefferson Balance & Hearing Center can perform various tests to evaluate different portions of your balance/vestibular system. The audiology and otolaryngology team will determine which testing is appropriate based on your symptoms and medical history.
Videonystagmography (VNG) or Electronystagmography (ENG)
Videonystagmography (VNG) records and measures eye movements using a set of specially designed goggles while Electronystagmography (ENG) uses electrodes for this purpose. Based on your abilities and medical history, your clinician will determine which test is most appropriate for you. Both tests yield the same results. If you have not had your hearing tested recently, you may be asked to complete a comprehensive hearing test as well. A hearing test is recommended for patients with balance/dizziness symptoms because the balance/vestibular system (semi-circular canals) is intrinsically linked to our cochlea (organ of hearing). Together, they make up the inner ear. Some balance disorders have very specific hearing loss patterns. This will provide your physician with additional information to help him/her make a more accurate diagnosis.
VNG/ENG testing consists of three subtests:
- Oculmotor tests: visual tests that record the eyes' response to moving stimuli
- Positional/positioning tests: moving your head and body into different positions
- Caloric tests: stimulating your inner-ear canals (semi-circular canals) by introducing warm and cool air, or water
Testing can take up to two hours depending on which subtests are warranted. We request you do not eat for approximately 4 hours before your visit as some tests may elicit an upset stomach. However, if you are diabetic or do need to eat, light foods such as toast and crackers are permitted. Some medications may also impact the validity of test results and will need to be stopped approximately 48 hours prior to testing.
If you have any questions regarding stopping any medication listed, you must discuss this with the prescribing physician. If you cannot go off the listed medications per the prescribing physician, we will make note of it when interpreting your results.
The rotational chair test is very useful in determining if your balance problem is in one or both ears. Testing can be done alone or in conjunction with the VNG test to evaluate the balance/vestibular system more comprehensively. It allows measurement of responses to movements of the head that are closer to speeds encountered in daily activities. During this test, the patient sits in a computerized chair that slowly moves from side to side. The rotational chair test is very useful in determining if an individual has a problem with both sides of the vestibular system (bilateral vestibular loss).
The vHIT is an ear-specific test that detects disorders of the vestibulo-ocular reflex and can test all six of our semi-circular canals; traditional testing can typically only test two of these canals. This emerging test can evaluate several parts of the vestibular system simultaneously in addition to providing ear-specific information.
Electrophysiology encompasses a variety of tests that look beyond the cochlea for disorders that may result in hearing or balance problems. Tests may include but are not limited to Auditory Brainstem Response (ABR), Electrocochleography (ECochG), and Vestibular Evoked Myogenic Potentials (cervical or ocular VEMP).
- Auditory Brainstem Response (ABR): An ABR test may be performed to determine if you have delayed neural response due to a disturbance of the auditory nerve. It measures the speed of electrical impulses traveling along the auditory nerve from the inner ear to the brain. This safe and painless test can also be used to approximate hearing thresholds in individuals who may not be able to perform traditional hearing tests.
- Electrocochleography (EcochG): The EcochG test is an objective measure of the electrical potentials generated in the inner ear fluids as a result of sound stimulation. This test is most often used to determine if the inner ear (cochlea) has an excessive amount of fluid pressure. Excessive fluid pressure in the cochlea may cause (not exclusively) symptoms such as hearing loss, fullness of the ear, dizziness, and/or tinnitus.
- Vestibular Evoked Myogenic Potentials (VEMP): The VEMP test is a tool used to evaluate additional functions of the inner ear not available for evaluation in other tests. A myogenic (muscle) response from the neck or around the eyes is recorded in response to sound stimulation.