Vestibular Autorotation Test (VAT®) was developed as a method of evaluating the vestibulo-ocular reflex (VOR) .

* High frequency ( 2-6 Hz) VOR test
( range of normal everyday locomotion )

* Active head rotation

* 18 second test

* Tests both the horizontal and vertical canals

* Comfortable

* Portable

* Report Writer

Diagnostic Information


For most of the population, balance control occurs at an unconscious level. Signals from the inner ear continuously drive the eye muscles to coordinate eye movement with head movement. This coordination is necessary to have clear vision and balance. The communication between the ear and the eye is called the vestibulo-ocular reflex (VOR). When the VOR is functioning properly, eye speed and timing are equal and opposite to those of the head. But, if the speed or timing is off, even slightly, vision is distorted because of apparent motion of the visual field.

The VAT® is an 18 second test of the high frequency horizontal and vertical VOR’s for diagnosis, treatment planning and monitoring of vestibular disease. The frequency tested ( 2 - 6 Hz) closely approximates normal head movements. For example, many patients complain of dizziness or loss of balance when they are walking, bending over or turning their head quickly. The VAT® quickly and comfortably monitors a patient’s head and eye motions to record what is happening in the vestibular portion of the inner ear.

Testing with the VAT® often identifies problems not found with other vestibular tests, because the VAT® tests natural, faster motions and unlike other conventional vestibular tests, evaluates both the horizontal and vertical canals. Because the VAT® is sensitive to changes of the VOR and is easy to perform, it is often the first screening test a patient receives who complain of dizziness or balance problems. Patients do not object to repeated testing which makes the VAT® the ideal test to monitor ototoxic medication and vestibular rehabilitation.

The data shown below illustrates the VAT® test results from a gentamicin ototoxicity patient. The normative data is shown as the blue error bars ( ± 2 std.) Individual patient VAT® data are shown in various colors. Notice that both the horizontal and vertical gains (top two graphs) are well below the normal data. The horizontal and vertical phases ( bottom two graphs) are above the normal data. This data pattern is typically seen in gentamicin ototoxicity.