Question
We are getting a rotary chair. What are the current indications for the test? Which of the various rotary chair tests provide the most dignositic information (i.e. the SHA, VVOR,Step test, OPK)? Which of these tests is used the most? I always thought one of its primary uses was for monitoring pts on vestibulotoxic meds, but some of my referring physicians say no.
Answer
1. Indications for ordering Rotational testing
- Verify bilateral weakness found on caloric testing, including ice calorics
- If caloric testing is not possible for whatever reason
- Pediatric population if not testable with ENG
- Serial testing as in monitoring vestibulotoxicity or compensation over time
2. Which of the tests in the battery is most often used and gives the most useful information?
The SHA (Slow Harmonic Acceleration) test. It is the most robust and there are certain patterns of abnormality one is looking for. Most available information is written about this test. The Step Test is less robust and looks at the same information as SHA i.e. there is an inverse relationship between phase shift on SHA and time constant on the Step test. VVOR (Visual Vestibular Ocular Reflex) and VOR Fix (Vestibular Ocular Reflex testing with fixation) look at the interplay of vision with the VOR ie.the effect of vision on the VOR. Fixation suppression and OPK testing have already been tested in the ENG test, so they are redundant tests of the same function. The VVOR could tell just how disabled the patient is in that they should give a pretty much perfect response if they have vision and vestibular working together to give the response.
Peta J. Gates, M.A., CCC-A
Balance Assessment Product Manager
ICS Medical
A GN Otometrics Company
125 Commerce Drive
Schaumburg, IL 60173
e-mail: pgates@icsmedical.com
Peta J. Gates is an audiologist and Balance Assessment Product Manager for ICS Medical, a GN Otometrics Company. She received a B.A. in Speech Pathology & Audiology from the University of the Witwatersrand in Johannesburg, South Africa and an M.A. in Audiology from Northwestern University in Evanston, Illinois. She has practiced Speech Pathology and Audiology in both South Africa and the U.S. In her current position with ICS Medical she serves customers in a support capacity and assists with new product development.
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