Videonystagmography, or VNG, is a test performed by hearing clinics, which is used to examine nystagmus (involuntary movements of eyes) of patients suffering from vertigo. The test is carried out using a pair of goggles equipped with a camera to track and record the patient’s eye movements. With the help of this device, the vestibular system of the inner ear, which is responsible for creating balance in the body, is examined. VNG test is suitable for people who are experiencing symptoms of middle ear disorders.
Why Is Videonystagmography (VNG test) Performed?
The root cause of vertigos is disorders that occur in the inner ear. Videonystagmography or VNG tests evaluate the different parts of the body’s balance system to find the source of the problem. When an individual experiences vertigo, the eyes display rapid movements to maintain visual stability. These rapid movements recorded by the goggles are then analyzed by an audiologist to define the suitable treatment for the patient.
VNG Test
What Does a VNG Test Diagnose?
Videonystagmography, or VNG test for vertigo, is one of the most practical and useful paraclinical tests used to evaluate and examine patients with a history of dizziness and balance disorders. This type of test is considered an extremely accurate and effective test in diagnosing the cause of patients’ dizziness.
VNG test is typically used to diagnose vertigo and nystagmus. In addition, it is also used in people with ear pressure, tinnitus, and ear fullness. The most critical use of the Videonystagmography test is to evaluate and diagnose vertigo in patients. Among the types of vertigos examined with the VNG test is BPPV or benign paroxysmal positional vertigo. BPPV vertigo is a condition in which the patient experiences vertigo only in specific circumstances and postures.
Is a VNG Test Painful?
There is no need to worry about the complications of VNG tests, as the process is painless. However, you may feel dizzy or off-balance for a few moments during the test. This is normal due to the stimulation of the vestibular system and the reoccurrence of the conditions that caused the dizziness or vertigo. It is usually resolved quickly after the test is complete. The experience may be uncomfortable for some people, especially if they have previously had severe dizziness or nausea.
How Long Do VNG Tests Take?
The Videonystagmography, VNG test takes about 20 minutes or a little longer to complete. The time for the test to be complete depends solely on the audiologist’s method of working and how cooperative the patient is.
Preparing for a VNG Test
How Do I Prepare for a VNG Test?
To perform Videonystagmography or VNG testing, it is best to consider some precautions before performing the test.
- At least 48 to 72 hours before the test, avoid taking anti-vertigo, sleeping pills, and sedatives.
- Individuals who have a habit of drinking alcoholic beverages should cut down on drinking these beverages for at least two days before the test.
- Refrain from smoking tobacco because it can affect the final test results.
- If the test is performed on the patient in the morning, it is mandatory to consume a light breakfast. If the test is done in the afternoon, the patient is only allowed to eat breakfast and cannot consume food till the test is completed.
- Avoid wearing contact lenses during the test. It is important that the patient follow the recommended instructions. Instead, wearing glasses is possible until the test is finished.
- Do not wear eye makeup when doing VNG tests. Wash and clean the face thoroughly before performing the tests.
- Due to the possibility of severe dizziness and vertigo after performing the VNG test, it is necessary for someone to accompany the patient.
BPPV
Disorders That Require VNG Testing
Benign paroxysmal positional vertigo (BPPV)
The inner ear contains calcium crystals that help control balance. BPPV vertigo occurs when these crystals become out of place. This problem can make the patient feel like the room is spinning or the surroundings are moving. Benign paroxysmal positional vertigo is the most common cause of vertigo in adults.
Ménière’s Disease
This disorder causes dizziness, hearing loss, and tinnitus (ringing in the ears).
Labyrinthitis (Vestibular Neuritis)
Labyrinthitis is inflammation of the vestibular nerve within the inner ear. It is usually caused by a virus. Symptoms include nausea and dizziness.
Migraines
A migraine is a throbbing, severe headache and is different from other headaches. Its characterizing symptoms are nausea, cognitive dysfunction, and dizziness.
Injury in the scalp or brain
Experiencing dizziness or other balance symptoms is common after a head injury.
Drug Side Effects
Some drugs and medications cause vertigo or dizziness in certain groups of people.
VNG Test Procedure
VNG Test Procedure
The Videonystagmography or VNG test is performed by an audiologist who specializes in the diagnosis, treatment, and management of hearing and balance disorders. During the VNG test, the patient sits in a dark room and wears special goggles equipped with a camera recording the eye movements. VNG test is categorized into three parts which are:
Ocular Testing (Eye Examination):
In this VNG test, the person must look at fixed or moving bright spots on the screen or follow their movements.
Positional Testing:
During the positional test, the specialist will move your head and neck into different positions, and if these movements cause nystagmus, they will be recorded.
Caloric Testing:
In caloric testing, hot or cold air or water is put into each ear individually, which then stimulates the inner ear and causes nystagmus. The audiologist reports on the presence of balance problems by examining eye movements.
Final VNG Test Results
After the test is completed, the specialist will provide a report based on the recorded results. This report will include information about the type of vertigo (peripheral or central), the severity of the disorder, and treatment recommendations. The two types of vertigo include:
- Peripheral vertigo: This is caused by a disorder in the inner ear and is usually treated with balance exercises or certain medications.
- Central vertigo: This is related to a disorder in the brain or central nervous system and may require further testing or counseling with the doctor.
The accurate analysis of these tests aids healthcare professionals develop an effective and targeted treatment plan for the patient. If you have vertigo, having these tests done and consulting with a balance specialist can provide helpful strategies to improve and prevent your symptoms.
VNG Test Cost
VNG Test Cost
The costs of performing Videonystagmography or VNG test are estimated entirely based on the fixed taxes imposed by the Ministry of Health. Also, patients covered by supplementary insurance (health insurance) will pay less for the test because the insurance company will cover part of the costs.
VNG Test Cost in Iran
Generally, the cost of VNG tests depends on various factors; for example, the doctor may recommend one or two parts of the test for one patient and all parts for another. In this case, the cost of the test will vary based on the diagnosis procedure. Note that some clinics in Tehran, in addition to performing VNG tests, also provide treatments and rehabilitation for their patients.
Currently, the average cost of VNG testing in Iran ranges from 200,000 tomans (2,000,000 Rials) to 1,000,000 tomans (10,000,000 Rials). These prices can change over time due to many reasons. Keep in mind that clinics offer different costs depending on the devices used, the specialist who performs the tests, etc.
Final Word
Patients who experience symptoms such as balance problems, persistent and prolonged dizziness, a feeling of pressure or fullness in the ears, lightheadedness, and tinnitus that is ringing in the ears, vertigo are candidates for Videonystagmography testing. VNG testing is distinct from simple examinations. It requires special devices and expertise to perform the test. If you or someone around you has such symptoms, see an audiologist immediately for a full diagnosis of the condition.
