Vestibular testing is a category of tests used to determine if there is something wrong with the part of the inner ear involved in balance (vestibular). It is important to determine the cause of any dizziness in order to correctly treat the condition. These tests are also good at determining if more extensive tests, such as imaging tests, are required
Vestibular Evoked Myogenic Potential (VEMP)
Vestibular evoked myogenic potential evaluates the function of the saccule, an important part of the middle ear that helps maintains balance by translating head movements into neural impulses which are sent to the brain. These neural impulses also cause the sternocleidomastoid (SCM) neck muscles to relax. The VEMP test begins with you lying down; you will then be instructed to raise your head, which flexes the SCM neck muscles. The saccule is then stimulated by loud tones and the relaxation of your neck muscles is measured.
While the above-mentioned tests are most commonly performed, there are other tests that can be used to diagnosis vestibular issues. Electrocochleography (ECOG) is used to test for Ménière’s disease and swelling of the inner ear. An electrode is inserted into the ear canal. A series of clicks are played and the electrode measures the cochlea’s reaction to them.
A rotational chair test is commonly used to diagnose bilateral vestibular loss and consists of three parts: the chair test, the optokinetic test and the fixation test. Your level of dizziness during each test is measured by recording eye movement. The chair test measures your level of dizziness while being slowly turned in a motorized chair. The optokinetic test measures how dizzy you become while viewing moving stripes. The fixation test measure dizziness while you are being rotated and the dot you are instructed to look at is also rotating.
Video Head Impulse Testing (vHIT)
Sometimes dizziness is caused by abnormalities in the vestibular ocular reflex (VOR), meaning the patient’s eye movements do not correlate with their head movements. The video head impulse test (vHIT) uses new technology to determine if the patient’s VOR is impaired. The test is conducted by attaching a high-speed, lightweight video goggle to measure the eye’s velocity when moving left to right during natural head movements.