VNG, or videonystagmography, measures a type of eye movement you cannot control, called nystagmus, in order to test how well your inner-ear balance system and the balance pathways in your brain are working.1 It is a diagnostic test, not a treatment, and it does not measure peripheral nerve function at all.
In someone who already has neuropathy, it answers one narrow and useful question: is part of the unsteadiness coming from the vestibular system rather than from the nerves in the feet? That distinction changes what the balance plan should look like.
What the test records
A camera inside a pair of goggles records your eye movements while the examiner changes what you are looking at, where your head is, and the temperature inside your ear canal.
Brief nystagmus is normal as the eyes adjust when the head moves into certain positions. Nystagmus that appears at other times, or fails to appear when it should, may indicate a disorder of the balance system in the inner ear.1
That is what makes it worth doing. Eye movement is involuntary, so the recording is an objective signal in a situation where the symptom itself — feeling unsteady — is notoriously hard to describe.
The three parts of the test
A VNG has three main components, and each probes a different part of the balance circuitry.1
- Ocular testing. You follow moving lights and hold your gaze on steady lights without moving your head.
- Positional testing. Your head and body are moved into different positions while the goggles watch for nystagmus.
- Caloric testing. Each ear is tested on its own, first with cool water or air and then with warm water or air in the same ear.
What the caloric portion is looking for
The cool temperature should make the eyes move in a particular way, and the warm temperature should produce a different response.1 Testing one ear at a time is what allows the two sides to be compared.
When the eyes do not move as expected during caloric testing, it may mean there is damage in the inner ear or in the part of the brain that controls balance.1 Abnormal VNG results are also associated with conditions such as benign paroxysmal positional vertigo, Ménière disease, labyrinthitis and vestibular neuritis.1
Why this matters when you have neuropathy
Standing upright depends on three inputs: sensation from the feet and legs, vision, and the vestibular system. Peripheral neuropathy degrades the first one. If the third one is also impaired, the loss compounds, and a person who could compensate for one problem cannot compensate for two.
Patients often describe both at once — numb feet and a swimming, off-balance feeling — and it is easy for everything to get attributed to the neuropathy. Testing separates them.
Balance can fail in more than one place at a time
Sorting this out is not academic. Vestibular findings direct one kind of rehabilitation, while sensory loss in the feet directs another, including footwear, lighting, home hazards and the protective habits that matter when the feet no longer report injury.
Getting the proportions right is how a fall risk gets addressed rather than described.
What VNG does not tell you
VNG does not identify your neuropathy driver. Peripheral neuropathy is a category rather than a diagnosis, and the work of finding out whether the cause is metabolic, nutritional, autoimmune, toxic or structural happens elsewhere in the evaluation.
It also does not treat anything. A normal VNG is useful information — it moves the balance problem back toward the feet — but neither a normal nor an abnormal result is a therapy.
How it fits into an evaluation at Regenerve
Electrodiagnostic testing (EMG/NCS) is performed on site and characterizes how the peripheral nerves are conducting. VNG is used when balance, dizziness or fall history suggests the vestibular system may also be involved.
The two are read together, alongside your symptom timeline, medications and metabolic and nutritional workup. Our page on VNG balance testing covers what to expect on the day of the test itself.
Bring the specifics with you: when the unsteadiness happens, whether it is worse in the dark, whether the room spins or you simply feel adrift, and whether you have fallen. Those details shape how the results are interpreted.
Start with the Nerve Damage Score
The Nerve Damage Score is five questions, and it is free. It is the starting point for identifying which driver is most likely damaging your nerves, which is the piece VNG cannot supply. We do not promise that nerve damage can be regenerated or reversed.
Regenerve, 4477 Woodson Rd #104, St. Louis, MO 63134. Call or text (314) 886-5902, or email info@regenerve.com. We are minutes from St. Louis Lambert International Airport and see patients from across the St. Louis region, Missouri and Illinois, including Edwardsville, Glen Carbon, Collinsville, Troy and Maryville.
Frequently asked questions
What does VNG balance testing measure?
It records involuntary eye movements, called nystagmus, with infrared goggles, and uses the timing and conditions of those movements to assess the inner-ear balance system and the balance pathways in the brain. It is a diagnostic test, not a treatment. See our VNG balance testing page.
Is VNG the same as nerve testing for neuropathy?
No. VNG evaluates vestibular function through eye movement, while electrodiagnostic testing (EMG/NCS) measures how peripheral nerves conduct. They answer different questions and are often ordered together when both feet and balance are involved. See the testing and care we provide on site.
Can VNG tell me why my feet are numb?
It cannot. Numbness in the feet is a peripheral nerve finding, and VNG does not measure peripheral nerves at all. What it can do is show whether some of your unsteadiness is coming from a second problem in the inner ear. See peripheral neuropathy of the feet symptoms.
Why would someone with diabetes be sent for balance testing?
Because unsteadiness in diabetes is rarely one thing. Reduced sensation in the feet, vision changes and vestibular problems can all contribute at once, and the plan differs depending on which is dominant. See diabetic peripheral neuropathy treatment in St. Louis.
What happens if my VNG is abnormal?
An abnormal result points to the vestibular system or the balance-related pathways in the brain, and it directs the balance side of your care. It does not identify the driver behind your neuropathy, so that mapping still has to happen separately. See the hidden drivers of peripheral neuropathy.
Sources
- MedlinePlus, National Library of Medicine. Videonystagmography (VNG). MedlinePlus Medical Test. Last updated 28 June 2023. medlineplus.gov