ENG is performed to evaluate the acoustic nerve, which is integral for hearing and helps with balance. This test may be recommended when a person is experiencing dizziness or vertigo, when there is impaired hearing with suspected toxicity from certain antibiotics, and when psychological causes of vertigo are suspected.
There are four main parts to the ENG:
- The calibration test evaluates rapid eye movements.
- The tracking test evaluates movement of the eyes as they follow a visual target.
- The positional test measures dizziness associated with positions of the head.
- The caloric test measures responses to warm and cold water circulated through a small, soft tube in the ear canal.
The ENG test can also diagnose ear disorders affecting only one ear, such as vestibular neuritis, benign paroxysmal positional vertigo (BPPV) and bilateral vestibular loss.
The calibration and tracking tests are intended to diagnose central nervous system disorders such as cerebellar degenerations.
Patches called electrodes (similar to those used with EKG, but smaller) are placed above, below and to the side of each eye. They may be attached by adhesive or by a band around the head. Another electrode is attached to the forehead.
This test stimulates the inner ear and nearby nerves by delivering cold and warm water to the ear canal at different times. Sometimes, the test is done using air instead of water. Each ear is tested separately.
When cold water enters the ear, it should cause rapid, side-to-side eye movements. The electrodes record eye movements and a computer records the results. Patients may also be asked to use their eyes to track objects, such as flashing lights.
The test takes about 90 minutes.
- Do not take tranquilizers, sedatives, antihistamines, decongestants, muscle relaxants, aspirin, pain pills, diet pills, medication to prevent dizziness or alcoholic beverages for at least 48 hours before the test. Even the smallest amount of these drugs in your system will give us inaccurate test results. If you are epileptic, have heart disease or high blood pressure, continue with your medications as prescribed by your doctor.
- No caffeine products such as coffee, tea, cola or chocolate for four hours prior to the test.
- No smoking for four hours prior to the test.
- No eating for four hours prior to the test. If you have diabetes or low blood sugar, you may eat lightly.
- Do not wear make-up, lotions or face cream.
- If you wear eyeglasses, bring them with you. Do not wear contacts.
- Please wear comfortable clothing.
- The dizziness caused by the testing lasts only a short time, but you may be more comfortable bringing someone with you to drive you home.
- If you are unable to keep your appointment, please call 313-966-4725 to cancel at least 24 hours before your scheduled appointment time.
Please plan to arrive 15 minutes before your scheduled appointment to allow time for registration.
For more information about DMC Sinai-Grace Hospital’s audiology and hearing services or to make an appointment, call 313-966-4725.