Videoelectronystagmography (VNG)
Videoelectronystagmography or (VNG) involves three main components:
- A test of oculomotor functioning -- using the video goggles to analyze and record the eyes ability to follow objects both smoothly and rapidly.
- Positional testing -- the eyes are recorded as a patient is put in different positions, i.e., lying down, head turned to the right, etc..
- Caloric testing -- warm and cold air is introduced to both ears separately while the movement of the eyes is recorded.
The eyes are recorded from because the movements of the eyes are linked to the vestibular system. The vestibular system is sometimes referred to as the inner ear. The vestibular portion of the inner ear is connected through the eyes by something called the vestibular-ocular reflex or VOR. Measuring and recording the eyes allows access to information on a patient's inner ear and helps pinpoint where issues may be occurring.
Oculomotor exams provide neurological information. Specifically, they provide insight into how well an individual's brain is coordinating movements in response to speed, accuracy and smoothness.
Positional testing is done to flush out issues such as BPPV, or benign paroxysmal positional vertigo. BPPV is the most common balance problem and it involves short periods of dizziness that are provoked by head movement.
Caloric testing allows clinician's to compare one side of the head to another in respect to health of the inner ear/vestibular system as well as to confirm or refute the presence of any inner ear functioning at all.
