Department of Audiology

Common Questions and Answers About Balance Function Testing

Q. 1) What balance tests are performed by the Nova Scotia Hearing and Speech Centres (NSHSC)?
A. 1) The NSHSC conducts three types of tests that assess balance function. These include Electronystagmography (ENG), Rotary Chair Testing, and Dynamic Platform Posturography.

ENG is used to assess patients who experience dizziness or vertigo. The ENG test battery has a number of sub-tests in which the patient’s eye movements (nystagmus) are recorded. The battery of tests include 1) the saccade test, 2) the gaze test, 3) the tracking test, 4) the optokinetic test, 5) the fixation suppression test, 6) positional testing, and 8) the bithermal caloric test. These tests assist in giving the doctor information on what the cause of the dizziness or vertigo might be and in monitoring changes in vestibular function over time.

Rotary Chair testing is a test which can be used along with ENG testing. The test battery includes 1) the Slow Harmonic Acceleration Test (SHA), 2) Optokinetics (OKN), and 3) Vestibular-ocular reflex with fixation suppression (VOR-FIX). Eye movements are measured at various speeds (0.01 to 0.64 Hz) and three parameters are measured including phase, gain, and asymmetry. Although this test allows the vestibular system to be tested over a wider portion of its operating range, it can not test each ear separately.

Dynamic Platform Posturography is a test which measures postural sway under six varying conditions. These conditions vary somatosensory, visual, and vestibular inputs to assess a person’s ability to maintain an upright stance. These three conditions are examined for their contribution to a person’s balance. Results can be used for a number of reasons including monitoring vestibular rehabilitation and documenting whether a problem in postural control is present.

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