At an audiologist, they will typically offer a procedure called videonystagmography, more conveniently referred to as VNG testing, to find out whether you have a disorder in your vestibular system, the part of the ear that controls balance, or in the part of your brain that controls balance.
These centers do VNG testing for patients who present dizziness as a symptom. Dizziness is just a general term for imbalance. It can result in a sensation like vertigo, in which you feel that your surroundings are spinning around you. Or you may stagger as you walk. Some people also feel like they are going to faint with this condition.
Other symptoms of a vestibular condition include:
- Confusion. The constant sensation that your surroundings are moving around when they physically aren't, is disorienting,
- Nystagmus, involuntary eye movements that go right to left or up and down.
- Tinnitus, ringing or buzzing in the ears.
- Feeling of pressure or fullness around or in the ear.
An important reason to get these kinds of symptoms checked out by your audiologist is the risk of falling. About 25 percent of people over 65 who have a vestibular disorder take a fall, sometimes with serious consequences. Younger patients tend to have some kind of warning sign before they take a fall, so they can brace themselves or find a place for a soft landing. Over 30 percent of people over the age of 80 who have a vestibular disorder will fall, a Swedish study found, without any warning signs.
Lots of people have this problem. About 5 to 10 percent of adults of all ages have some degree of dizziness, vertigo, and poor balance.
What Happened to Me That I Need to Have This Kind of Testing?
By the time you have the symptoms of vestibular disease, there are concerns for your personal safety, diagnosis and treatment are essential, and the test isn't really something you should put off. But it probably wasn't anything you could avoid, either.
The most common underlying conditions that result in peripheral vertigo include benign paroxysmal positional vertigo, a condition that gives you the sudden sensation that you are spinning or the inside of your head is spinning. It can also spring from migraine, inflammation of the vestibular nerves, or acoustic tumors.
The immediate cause of symptoms, however, no matter what the underlying cause, is some kind of disturbance to the movement of fluids in the ear. This gives your audiologist and your ENT a starting place to improve your condition.
What is Done During Your VNG Test
VNG testing can be done by a primary care provider, an otolaryngologist (ENT), or a neurologist, however it's usually done by an audiologist.
During your VNG test, your audiologist will ask you to sit in a dark room and wear special goggles. The goggles contain a camera that will record your eye movements.
There are three parts to the test.
Ocular testing. During this part of your VNG test, you will be asked to watch and follow moving and nonmoving lights on a light bar.
Positional testing. In this part of your VNG test, your audiologist will move your body and head into different positions to see if this changes the way your eyes follow the light sources. Your audiologist will be looking to see if changes in position cause nystagmus, side to side, or up and down movements in your eyes.
Caloric testing. In this part of your VNG test, your audiologist will put warm or cold water or air into each ear to see if they cause changes in the way your eyes move. When the audiologist puts cold water or air into your ear, your eye should move away from it. When the audiologist next puts warm water or air into your ear, your eye should move back to its original position.
Your audiologist will check to see if both eyes respond in the same way. If one eye doesn't respond as much or respond in the same way, there may be damage to the nerves in your inner ear. If the responses in both ears are weak, or there is no response at all, the nerves in both inner ears may be damaged.
Do I Need to Do Anything Before VNR Testing?
You may need to change your diet for a day or two before your VNR test. Your audiologist will let you know before the test.
Are There Any Risks with VNR Testing
VNR testing may make you dizzy for a few minutes. You may want to make arrangements for someone to drive you home from the clinic, just in case, the dizziness lasts longer than expected.
What Do the Results of VNR Testing Mean?
Abnormal test results can mean you have a disease of the inner ear, such as labyrinthitis or Meniere's disease.
Labyrinthitis is a disorder that results in imbalance and vertigo. It occurs when part of the inner ear has become swollen or infected. Sometimes it goes away on its own, or you may need antibiotics.
Your audiologist is usually available to explain your results to you.
There is another test called electronystagmography (ENG) that measures the same kinds of eye movements as a VNG. Instead of using a camera to make a record of your eye movements, this test measures eye movements with electrodes the operator places on your skin around your eyes. It's generally not as accurate as VNG.
While ENG testing is still being used, VNG testing is now more common. Unlike an ENG, a VNG can measure and record eye movements in real-time. VNGs can also provide clearer pictures of eye movements.