Part 1: What is VNG?

Host, Veva Hurtado: Hello, and welcome. My name is Veva Hurtado and I am accompanied by Mindy Norris. We are vestibular audiologists with Intermountain Health. If you’ve been scheduled for a VNG test and you’re feeling a little unsure about what to expect, you’re in the right place. Today, we are going to walk you through the test step by step, explain why it’s done, and help you feel more prepared and at ease before your appointment. To begin, Mindy, how would you describe what a VNG test actually is?

Interviewee, Mindy Norris: VNG stands for videonystagmography. It’s a diagnostic test that evaluates how well your inner ear and brain are working together to maintain balance and interpret motion. This test is often recommended for people experiencing dizziness, vertigo, or a general sense of imbalance. By analyzing your eye movements during specific tasks, the VNG helps us identify which parts of the balance system may not be functioning as expected.

Hurtado: Thank you. Next, could you explain the introduction you typically give patients before a VNG test?

Norris: A VNG gives us incredibly useful insight into how your inner ear and brain are working together to maintain balance and process movement. By studying your eye movements during specific tasks, we’re able to pinpoint whether dizziness is coming from the inner ear—or whether it may be related to how the brain is interpreting balance signals. In other words, this test helps us understand what might be contributing to your symptoms and guides your medical team toward the most effective treatment plan.

Part 2: How the Test Works

Hurtado: Great. Can you walk us through how the test works?

Norris: Your inner ears and your eyes are connected through something called the vestibular ocular reflex. This reflex helps keep your vision steady when your head moves. During the test, we take advantage of that connection by observing your eye movements. You’ll wear a pair of special goggles with small cameras inside them. These cameras allow us to track your eye movements very precisely while you complete a series of tasks.

Hurtado: Now, you’ve mentioned this test requires completing a series of tasks, does that mean the VNG has multiple components? 

Norris: Yes, the VNG test is made up of three main sections: oculomotor, positional/positioning, and caloric.

Part 3: Oculomotor Testing

Hurtado: Let’s begin with the first section. How do you explain the oculomotor portion?

Norris: The first section focuses on the oculomotor system—essentially how well your eyes move, track targets, and coordinate with your brain. For this part, you’ll sit comfortably in front of a monitor and focus on a visual target, usually a small dot on the screen. You’ll be asked to follow the dot using only your eyes while keeping your head still. The dot may move smoothly across the screen, jump from point to point, or shift side to side. As you follow it, we observe how fast, accurate, and consistent your eye movements are, as well as whether any unexpected or involuntary eye movements occur. From this portion of the test, we can gather information about whether your symptoms may be related to the inner ear—what we call the peripheral vestibular system—or to the brain, which is referred to as the central system.

Part 4: Positional and Positioning Testing

Hurtado: Thank you. What happens in the second section of the VNG, or the positional/positioning component as you referred to earlier?

Norris: The second section of the test involves changing the position of your head and body.
You may be asked to lie on your back, turn your head to different sides, or lie comfortably with your head supported on a pillow. In some cases, your head may be positioned slightly below your shoulders. During these movements, we’re watching for involuntary eye movements called nystagmus and noting whether certain positions trigger dizziness.

This portion of the test is most often used to help rule out a condition called benign paroxysmal positional vertigo, or BPPV—sometimes described as “crystals in the ear.” These tiny crystals, called otoconia, normally help your body sense gravity. If they become displaced, they can cause brief episodes of true spinning vertigo when your head moves into certain positions. BPPV is actually the most common cause of dizziness, and the good news is that it can often be corrected with a simple treatment called a repositioning maneuver, which helps guide those tiny displaced crystals back where they belong.

Part 5: Caloric Testing

Hurtado: Excellent. Now what does the final portion, caloric testing, involve?

Norris: The third and final section of the VNG test is called caloric testing. During this part, warm and cool air—or sometimes water—is introduced into the ear canal for about 30 seconds to a minute. In our clinic, we use air at both warm and cool temperatures.
These temperature changes cause the fluid in the inner ear balance system to move, which creates distinct eye movements we are able to record and analyze. This allows us to measure how well each inner ear is functioning and to compare the right side to the left, given symmetry between the ears is important for balance and stability.

It’s very common to feel dizzy while the air is being delivered to the ear and for a short time afterward. Less commonly, this part of the test can also cause nausea or vomiting. Because of this, we ask patients not to eat for about three to four hours before their appointment.

We also ask that you avoid certain medications for about 48 hours beforehand, especially medications that can sedate or affect the central nervous system. These may include anti dizziness medications like meclizine, anti-nausea medications, sleep aids, strong pain medications, alcohol, or antihistamines.

Part 6:  Test Results

Hurtado: Once the test is complete, what should patients expect?

Norris: In most cases, the results of a VNG test are analyzed in real time, meaning your audiologist can often discuss findings with you shortly after testing is completed. Whether the results indicate a peripheral issue, a central issue, or another cause, the results will offer helpful insight into what may be contributing to your symptoms. Your audiologist will ensure the results are shared with your referring physician, who will help direct any necessary follow up care or additional evaluation. 

Hurtado: And finally, what closing message do you share with patients?

Norris: We know that dizziness and balance issues can be stressful, and our goal with VNG testing is to gather clear, helpful information that guides your care, while making sure you feel informed and supported every step of the way.

Hurtado: If you have any questions before your appointment, don’t hesitate to reach out.
Thanks for listening.