Videonystagmography (VNG)

Videonystagmography (VNG) is a diagnostic test used to evaluate the vestibular system and balance function. It is a non-invasive procedure that uses video cameras to record the movements of the eyes.

What is VNG used for?

VNG is used to diagnose and evaluate various balance-related disorders, including:

• Benign paroxysmal positional vertigo (BPPV)
• Labyrinthitis
• Vestibular neuritis
• Ménière's disease
• Balance disorders
• Dizziness and vertigo

How is VNG performed?

The VNG test typically involves the following steps:

1. The patient sits in a chair or lies on an examination table.
2. A headset with video cameras is placed on the patient's head to record eye movements.
3. The patient is asked to perform various tasks, such as:
• Looking at a fixed point
• Tracking moving objects
• Performing caloric testing (warm or cool air is introduced into the ear canal to stimulate the vestibular system)
• Undergoing rotational testing (the patient's head is rotated to stimulate the vestibular system)
4. The video cameras record the patient's eye movements during these tasks.
5. The recordings are then analyzed by a computer to assess the function of the vestibular system and identify any abnormalities.

What do VNG results show?

VNG test results can show:

• Nystagmus (abnormal eye movements)
• Vestibular function
• Balance function
• Eye movement abnormalities

Benefits and limitations of VNG

The benefits of VNG include:

• Non-invasive and painless procedure
• Accurate diagnosis of balance-related disorders
• Helps to identify the underlying cause of symptoms

The limitations of VNG include:

• May not detect all types of balance-related disorders
• Requires specialized equipment and trained personnel
• May be affected by certain medications or medical conditions

Frequently Asked Questions (FAQs)

What is Videonystagmography (VNG)?
A test used to evaluate balance and vestibular function by recording eye movements.

How is VNG performed?
It involves wearing special goggles with cameras to record eye movements in response to various visual and caloric stimuli.

What are the typical components of a VNG test?
Ocular motor testing, caloric testing, positional testing, and rotational testing.

Is VNG used to diagnose specific conditions?
It can help diagnose vestibular disorders, such as benign paroxysmal positional vertigo (BPPV), labyrinthitis, and vestibular migraine.

Are there any preparations needed before a VNG test?
Patients may be asked to avoid certain medications, caffeine, and alcohol beforehand, and to remove contact lenses and eyeglasses.

Is the VNG test painful or uncomfortable?
Generally not painful, but some patients may experience dizziness or discomfort during caloric testing.

How long does a typical VNG test take?
Approximately 60-90 minutes.

Can children undergo VNG testing?
Yes, but it may require special accommodations and cooperation from the child.

Are the results of VNG testing immediately available?
Typically not, as the recordings need to be analyzed by a healthcare professional.

Is VNG testing covered by insurance?
Usually covered, but coverage may vary depending on the specific insurance plan and medical necessity.