Dizziness & Balance Testing
Computerized test of head and eye movements to evaluate both the high frequency horizontal and vertical vestibulo-ocular reflex (VOR). The VOR system stabilizes fixation of the eyes during head rotation by causing the eyes to move in the opposite direction of the head motion. The main purpose of the VOR is to allow clear vision during movement by sending signals to move the eye muscles to compensate for the small rapid head movements that occur in everyday life. However if the speed or timing is off, even slightly, vision is distorted because of apparent movement of the visual fields. The VAT tests the normal, everyday range of head motion where many balance disorders occur. The computer analyzes head motion and simultaneous eye movements. Electrodes record eye movement while a velocity head sensor records head movement. The VAT is used in the diagnosis of inner ear disturbances and also to monitor changes. The VAT is comfortable and easy to perform.
Electronystagmography (ENG) is used to evaluate people with vertigo (a false sense of spinning or motion that can cause dizziness) and certain other disorders that affect hearing and vision. Electrodes are placed at locations above and below the eye to record electrical activity. By measuring the changes in the electrical field within the eye, ENG can detect nystagmus (involuntary rapid eye movement) in response to various stimuli. If nystagmus does not occur on stimulation, a problem may exist within the ear, nerves that supply the ear, or certain parts of the brain. This test may also be used to distinguish between lesions in various parts of the brain and nervous system.