What is Electronystagmography (ENG)?
Electronystagmography (ENG or electrocardiogram) is used to evaluate people with vertigo (a false sense of spinning or movement that can cause vertigo) and some other disorders that affect hearing and vision. Electrodes are set at areas above and underneath the eye to record electrical activity.
By measuring changes in the electrical field within the eye, ENG can detect nystagmus (rapid, involuntary eye movement) in response to various stimuli. If nystagmus does not occur upon stimulation, there may be a problem within the ear, the nerves supplying the ear, or certain parts of the brain. This test may also be used to distinguish lesions in different parts of the brain and nervous system.
Purpose of an ENG
ENG detects disturbances in the parts of the inner ear responsible for steering, posture, and balance, as well as in the nerves that connect your brain to your eyes and ears.
Your doctor may recommend this test if you have any of the following symptoms:
- Severe or persistent dizziness
- Vertigo (meaning the room is spinning)
- Problems with balance
- Unexplained hearing loss
Your doctor may also perform ENG if you have any of the following conditions:
- Usher syndrome: A genetic disorder that affects vision, balance, and hearing
- Acoustic neuroma: A benign tumor of the auditory nerve (vestibular-cochlear)
- Labyrinthitis: Inflammation of the inner ear
- Meniere’s disease: A problem of the inward ear that influences equalization and hearing
- Any suspected lesion on your inner ear
What are the risks of an ENG test?
There is very little risk of Electronystagmography (ENG). A few people may encounter wooziness or sickness during the test. Electronystagmography (ENG) ought not to be utilized in the event that you have a pacemaker. The device may interfere with the pacemaker function.
Rapid changes to the posture needed for the test may worsen back or neck problems. The test for calories in water may cause mild discomfort. If you have previously been diagnosed with a perforated tympanic membrane, you should not have a portion of water calories on the ENG test.
There may be various risks depending upon your specific affliction. Talk about any worries with your medical services supplier before the strategy. Certain factors or circumstances may interfere with ENG. These include:
- Impaired vision
- Frequent blinking
- Certain medicines, those are sedatives, tranquilizers, and anti-vertigo medicines
How to prepare for the test?
Before the tests, you’ll likely be asked to do the following:
- Tell your doctor about the medications you are taking: It may ask you to stop taking it 72 hours before the test.
- Abstain from caffeine and alcohol: No drinking or coffee for 48 hours before the completion date.
- No food: Most doctors recommend avoiding eating at least 4 hours in advance.
- Clean your ears: Ear blockage and earwax can distort the results, so a medical assistant may wash the ear canals before the procedure if they are not clear.
- Prepare a trip afterwards: Usually, this is good advice for many medical procedures, just in case you do not want to drive.
The test can be distorted if you have double vision or blink a lot. Also, you shouldn’t have an Injex device if you have a pacemaker for your heart. You can usually go home after your recovery, although the test can also be taken during a hospital stay. The test takes up to 90 minutes.
What happens during an electronystagmography?
So now it’s time for ENG. You might be a little hungry, you might be tired, and you might be nervous. What can you expect? In fact, the procedure includes several tests. Prior to beginning, your primary care physician will clean your brow, sanctuaries, and cheeks with liquor. Then, you attach the electrodes to those areas using a paste.
In some testing facilities, instead of electrodes, you may be provided with a binocular camera that looks like virtual reality glasses. The tests performed with this system are known as videography or VNG. These devices capture your eye movements on video and can measure them just like electrodes.
The tests include:
- The calibration test: Utilizing just your eyes, you will be gotten some information about 6 to 10 feet away or think to and fro between focuses on a divider. This test measures visual impairment, a condition in which your pupils have difficulty judging distances to targets.
- The tracking test: Also known as the nystagmus test, it is similar to the sobriety test offered by the police. But in Muhandis, you are usually sitting or lying down. (Nystagmus is a condition in which your eyes are out of your control.) In this test, you try to stare at a steady light, directly in front of you or at an angle, without moving your eyes around you.
There are two related tracer tests:
- The first is the pendulum tracking test. In it, you are tracking a light that moves back and forth like a pendulum without moving your head.
- The other is the optokinetic test, in which you track multiple moving objects without turning your head. Things may move at high speeds and enter and leave your field of vision.
The positional test: Now is the time to move your head. Often your doctor will ask you to perform what is called the Dex-Halpike maneuver. While sitting at a table, you will turn your head to one side and quickly lie down with your head – supported by your doctor – about 20 degrees below the surface of the table. You’ll remain there for 30 seconds, at that point sit upstanding once more. You will repeat it with your head on the other side. Your doctor will notice the effect on your eyes.
The water caloric test: While lying down, your doctor will inject a stream of cold or warm water into one ear, then the other. (Air is sometimes used.) If you are not vertigo, your eyes should reflexively twitch. Your doctor may not perform all of the tests. On the off chance that you have neck or back issues, she may recommend something different.
After the electronystagmography test
- Once the test is finished, your provider will remove the electrodes and wash off the electrode paste. Do not rub your eyes to prevent spreading the electrode paste.
- Your provider will monitor you for any signs of weakness, dizziness, and nausea. You may need to rests or sit for a couple of moments to recuperate.
- Your healthcare provider will tell you when to start any medications you stopped taking before the test. Your healthcare provider may give you other instructions after the procedure, depending on your specific situation.
- You may also have vertical videography (VNG). This is a test that likewise identifies eye development. But it uses video cameras instead of electrodes.
If your ENG test results are abnormal, it could indicate a problem with your inner ear or the area of the brain responsible for controlling the movement of your eyes.
Other diseases or injuries to the auditory nerve can cause vertigo, including:
- Vascular disorders that cause bleeding in the ear
- Ear tumors
- Genetic disorders
- Damage to the inner ear
- Ototoxic drugs
- Multiple sclerosis
- Viral infections such as chickenpox, measles, and influenza
- Movement disorders
- Chemical poisoning