Videonystagmography (VNG) consists of several tests used to determine the cause of dizziness. There are many causes of dizziness and this series of tests evaluates the inner ear (vestibular system).
VNG examines a special type of eye movement called nystagmus. Nystagmus occurs when the brain attempts to determine the position of the body when it receives conflicting messages from the ears. Nystagmus lets the examiner know the position at which the patient is dizzy. However, nystagmus is not always position-related and not all causes of dizziness result in nystagmus.
There are 4 main parts of the VNG:
- Occular mobility. The patient watches steady and moving dots on a wall.
- Rotational chair. The patient’s chair rotates slowly to stimulate the inner ears.
- Positional nystagmus: The patient’s head and body are moved into different positions to determine if this causes nystagmus.
- Caloric testing: Air or water is instilled into the ear canal at different temperatures to stimulate the inner ear. This determines if one ear reacts differently from the other indicating an inner ear weakness.
Based on results from VNG, our specialists can assess a diagnosis and recommend treatment options.