Ear, Nose, & Throat - Audiology Testing
Kelly Tilson, Au.D.
The Videonystagnography Test (VNG) checks the integrity of your balance system. There are neural connections that stretch from the balance mechanism in the inner ear to the muscles of the eye. A disorder of the balance mechanism results in small, quick eye jerks called nystagmus that are recorded by a sophisticated computerized camera. The camera is attached to a pair of goggles that the patient wears. It records the eye jerks during a series of tasks. The tasks consist of looking back and forth between designated points, following moving lights, lying in different positions, shaking your head, and lying down and sitting up quickly. The final portion of the test requires putting cool and then warm air in each ear canal for roughly 60 seconds in order to determine if the balance mechanism of the ears respond normally to stimulation. The recorded nystagmus is then analyzed to determine a possible cause of the balance problems exhibited by the patient.
Please observe the following:
- No balance or nerve medication for 48 hours prior to the scheduled test.
- No alcohol for 24 hours prior.
- No food or beverages (except water) for 3 hours prior.
- No smoking for 3 hours prior.
- Females - no eye make-up of any sort, especially liner and mascara.
This test will likely cause some dizziness, however, this generally passes within a few minutes. It is advisable that you make arrangements for someone to be available to drive you home in the event of prolonged dizziness.
The Electrocochleography Test (EcoG) is used to aid in the diagnosis of Meniere's Disease. The test elicits nerve responses generated by the cochlea (inner ear) and 8th nerve when the ear is stimulated with click sounds. The patient is reclined in a comfortable chair. Surface electrodes are placed on the forehead and insert foam electrodes are placed in each ear canal. The patient is instructed to close their eyes and relax. During the test, a moderately loud clicking sound will be introduced into the ear canal, which will elicit a neural response from the inner ear. The neural response is picked up by the electrodes and passed on to computerized equipment, appearing as waveforms on the computer screen. The waveforms are measured and analyzed by the audiologist.
Auditory Brainstem Response
The Auditory Brainstem Response Test (ABR) is used to diagnose or rule out possible problems affecting the hearing system from the 8th nerve to the lower brainstem. It is a continuation of the ECoG Test and has a similar setup with electrodes. During the test, the patient hears moderately loud clicking and, at times, hissing sounds delivered to their ears. The electrodes pick up the electrical responses generated by your hearing nerves in response to the clicking sounds. The responses appear as wave tracings on the computer screen, which are analyzed according to their shape and the timing of the various wave peaks. The condition of your hearing nerves and other nervous system components that are responsible for hearing will be determined by this analysis.
If you have any questions about any of these tests prior to your scheduled appointment, please contact the audiologist at our Office, (703) 448-0005.