Rotary chair testing is performed to evaluate the vestibular system. The vestibular system includes structures of the inner ear, vestibular nerve, brain stem, and cerebellum (part of the brain). This system regulates balance, coordination, posture, and body orientation in space.
Rotary chair testing is usually performed in addition to videonystagmography/electronystagmography. The eyes and vestibular system together help see things clearly while moving the head. This reflex is called the vestibulo-ocular reflex (VOR). It helps perform routine activities such as reading street signs while walking down the street.
This reflex is the principle for rotary chair testing. It is measured using goggles with infrared cameras. Rotary chair testing can help determine if giddiness and/or imbalance are due to a problem in the vestibular system or central nervous system (the brain and spinal cord).
How is rotary chair testing performed?
The test is performed in an outpatient setting by audiologists. The patient is usually referred to the audiologist for testing by an ear, nose, and throat (ENT) surgeon or a neurologist.
Before the procedure
Patients must inform the doctor and audiologists performing the test of their complete medical history and medications they are on. The doctor may advise the patient to avoid certain medications 2 days before the test. It is advised to wear light and loose-fitting clothes to be more comfortable during the test.
During the procedure
During rotary chair testing, the patient sits in a rotational computerized chair (similar to the one used during an eye examination) placed in a small, dark room. A seatbelt and head strap are provided for security and to hold the upper body and head in place.
The patient wears infrared video goggles, which will record eye movements during the test. The patient sits alone in the room and can communicate with the doctor and audiologist outside the room through a microphone. The patient can inform the audiologist if they experience any symptoms such as giddiness, nausea, headache, or any discomfort during the test.
The test takes around 30 minutes and includes various sub-tests. During the tests, the patient’s eye movements will be carefully observed and recorded, specifically while measuring the vestibulo-ocular reflex (VOR) that occurs in response to the movement of the chair. This reflex is called nystagmus, which is a rapid, involuntary movement of the eyes from side to side and sometimes up and down.
There are two main parts of the test. The first part is called the oculomotor test, which measures eye movements in response to moving lights projected on the wall in front of the patient. The next part is the chair test, during which the patient would be turned at varying speeds in the rotary chair, and the eye movement would be recorded.
After the procedure
The patient may have some eye discomfort till they adjust to the light after having been in a dark room for 30 or more minutes during the test. They may feel unsteady or giddy for a few minutes. These problems are usually resolved after they rest for some time. The patient can go home and return to their regular activities when they feel comfortable after the procedure. Based on the test results, the doctor would be able to advise an appropriate treatment plan.