To assess what's causing your vertigo, the Balance Center at UCSF will give you a number of subtests that examine the effectiveness and interaction of the vestibular system, or inner ear, the somatosensory system, or flex and pressure sensors in your feet, and the vision system — as well as how these systems contribute to your overall stability and balance. The assessment helps determine which system or systems may be contributing to your symptoms and gives direction for treatment.
The assessment includes a videonystagmography (VNG) or electronystagmography (ENG) test. The VNG or ENG evaluation is separated into three subtests.
- Oculomotor: This assesses the oculomotor system, the visual system for balance. In this part of the test, we measure voluntary eye movements by having you complete a series of exercises while visually following a dot on a light bar.
- Positional or Positioning: This part of the test focuses on the vestibular system, which is the balance structure of the inner ear. We will ask you to move your head, or head and body, to monitor how the vestibular system reacts to these movements and to changes in gravity.
- Calorics: This measurement determines how well the vestibular system responds by applying warm and cool air into each ear canal separately. Comparisons are then made of the vestibular system's performance from one side to the other, and whether there's a possible weakness or hyperresponse in the inner ear. During the caloric test, it isn't unusual to experience a sensation of movement, which goes away immediately when the test is complete.
Reviewed by health care specialists at UCSF Medical Center.