More than 60 million people in America are suffering from the vestibular disorder, it can also be said like an issue of balance system in the body. To assess the balance disorder we must use the ENG and VNG test. ENG generally stands for Electronystagmography and VNG stands for Videonystagmography. Before knowing about ENG/VNG test, you should know that what is ENG and VNG.
It is used to test the vestibular system. And by testing vestibular system it can also diagnose the cause of imbalance in the body. It is basically a phenomenon to record the conscious control movement of your eye.
Purpose of Electronystagmography
It finds out any hidden problem in the inner portion of the ear which can cause orientation, balance, sense of the position, as well as the nerves which directly connects the brain to your eyes and ears.
Your doctor may recommend this type test if you have any of these symptoms:
- Unexplained hearing loss
- Severe dizziness
- A problem in the balancing
The ENG test will not occur if you are a patient of a cardiac pacemaker. For this situation VNG test will be the safest one.
VNG is the new standard over the Electronystagmography (ENG) because VNG directly measures the movement of the eye directly by the infrared rays, it does measure the movement of the by the electrodes around the eye as used by the ENG. It gives the person relaxation, and more comfortable form and having this VNG can achieve more accurate and right result. For this testing, goggles are placed near the eye and connected to the computer and record the movement of the eye.
How do Eng/Vng work?
In ENG, the electrodes are placed around the eye and these electrodes are been connected to the wires and through wires, the movement of the eye can be measured.
In VNG, goggles are placed near the eye and these goggles are connected through the wires. And these wires measure the movement of the eyes.
Both the VNG/ENG test measures the movement of the eye to evaluate any problem placed in neurological and vestibular system. This test occurs generally in the dark or in dim light rooms. In both the ENG/VNG test person gets in a comfortable manner and does not get any type of hurt.
What to expect when you are receiving an eng/vng test?
There are some parts of this testing:
PART 1: Oculomotor evaluation
In this technique, the patient is wearing the goggles in the eye and laying back comfortably. The patient is now can see the red dot appearing on their goggles and they were instructed to follow that red dot and that dot keeps moving i.e., not remain constant.
By following that dot by the patient’s eye the computer can record the movement of the eye.
And if the patient is having difficulty to track the red dot then it clearly shows the balancing problem in the body.
PART 2: Positioning of the body
In this technique, the doctor asks to move the patient’s body in different-different positions. This will help to refresh the different body organs. The main aim to see that in the patient’s body the vestibular system is working good in every position or not.
If you find yourself dizziness than it is the clear symptoms of having a dizziness in the patient’s body by having a different body movement.
PART 3: Static positioning
It is as similar to the part 2, as the patient is asked to move their head as well as the body in different positions. It is to see that the patient’s vestibular system is working properly or having any type of the disorder.
PART 4: Caloric testing
This testing is done usually at the done. It is the most important part of the testing because it will refresh all the vestibular system of the patient’s body. In this testing, the patient is lying back comfortably and now the doctors will put the warm water or air thrown at the patient’s ear. The air or water will remain for 45 sec-1 min in one ear and when testing is done by warm water now the testing is done by the cool water and air.
At this time it is necessary to follow the given instructions by the doctor to avoid the repeated test, as if it is said to close your eyes then you should follow that.
What does the patient do when this type of test occur?
Person’s work is just to sit comfortably on a chair and be alert so that the devices can record the movement of the eye. To keep alert the doctor’s keep asking some questions or they just talk to you like anything.
There are 3 parts for the test:
- The first part, it takes up with the patient sitting up in the chair and keep watching the moving light. This measures the visual system of your body.
- The second part, it takes up with the patient lay back comfortably and the eye movement is measured by the having a different body posture or the different head movement. It measures the effect in the body by different body postures.
- The third part, it takes up with the patient lying back comfortably with a different-different angle of the body. Then cool and warm air will be thrown into the patient’s ear to check the balance of the body.
Total ENG/VNG test take a time of about an hour. Before testing, you will be asked to take a light meal and should avoid alcohol. You must not have contact lens, and mascara on your eyes.
The main aim of ENG/VNG test is to check whether your body sustains any type of dizziness. The dizziness is caused by the abnormal behavior of your inner ear. If the test is not normal then you may be prescribed to have a further treatment. And if the test results come in a normal state then may be further check-ups are advised.
What are the risk of the test?
There are some limited risks in undergoing the ENG test like dizziness, or mild nausea. Those who will go under VNG test will experience the same affects and as well as the minor disorder in having the goggles for 1-2 hours of the testing. You will also find some uncomfortable in caloric testing.
In some conditions the following may be affecting the accuracy of an ENG:
- Impaired vision