Your healthcare provider can use electronystagmography (ENG) to evaluate vertigo and certain other hearing and vision disorders. Vertigo is a false sense of spinning or motion that can cause dizziness.
For this test, your healthcare provider places electrodes above and below the eye to record electrical activity. By measuring the changes in the electrical field within the eye, ENG can detect involuntary rapid eye movement (nystagmus) in response to certain stimuli. If it does not occur when stimulated, you may have a problem within the ear, nerves that supply the ear, or certain parts of the brain.
The ENG is actually a series of tests that may include one or more of the following measurements:
Your healthcare provider uses ENG to find disorders of the peripheral vestibular system, the parts of the inner ear that interpret balance and spatial orientation, or the nerves that connect the vestibular system to the brain and the muscles of the eye.
You may have this test if you have unexplained dizziness, vertigo, or hearing loss. These are symptoms, not a diagnosis. The ENG may help find the exact cause of your symptoms. Possible causes include:
If a known lesion exists this test can identify the actual site. There may be other reasons for your healthcare provider to recommend an ENG.
There are very few risks with ENG. Some people may have dizziness or nausea during the test.
ENG should not be used if you have a pacemaker because the equipment may interfere with pacemaker function.
Rapid changes in position required for the test may aggravate back or neck problems.
The water caloric test may cause mild discomfort. If you have been previously diagnosed with a perforated tympanic membrane, you should not undergo the water caloric portion of the ENG test.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your healthcare provider before the procedure.
Certain factors or conditions may interfere with ENG. These include:
You may have an ENG on an outpatient basis or as part of a hospital stay. Procedures may vary depending on your condition and your doctor's practices.
Generally, the ENG follows this process:
Once the test is done, your provider will remove the electrodes and wash off the electrode paste. Don't rub your eyes to avoid spreading the electrode paste.
Your provider will watch you for any signs of weakness, dizziness, and nausea. You may need to lie down or sit for a few minutes to recover.
Your healthcare provider will tell you when to resume any medicines you stopped taking before the test.
Your healthcare provider may give you other instructions after the procedure, depending on your particular situation.
Before you agree to the test or the procedure make sure you know: