Vestibular testing

What is vestibular testing?

Vestibular testing is a series of tests that check the functioning of the vestibular (balance) section of the inner ear. The vestibular system and the eyes work together to maintain balance and to maintain clear vision when the head is moving. This is known as the vestibular-ocular reflex (VOR). People who complain of dizziness will often go through vestibular testing.

What does vestibular testing involve?

Vestibular tests often use special equipment that monitor the eyes for normal and abnormal movements, whilst the vestibular section of the inner ear is stimulated.

There are different types of vestibular tests, including:

• Electronystagmography (ENG)
• Electrocochleography (ECOG)
• Rotation tests
• Video head impulse testing (VHIT)
• Vestibular evoked myogenic potential (VEMP)

Why is vestibular testing done?

Vestibular tests check the functioning of the vestibular section of the inner ear. If these tests can confirm its functioning, then symptoms like dizziness can be attributed to other causes, such as neurological disorders, low blood pressure, or psychological problems. However, first ruling out inner ear problems can save time on running other costly, time-consuming tests. 

Preparation for vestibular testing

Patients are advised to wear loose-fitting clothing on the day of testing and to avoid wearing make-up. 

Up to 48 hours beforehand the following must be avoided:

• alcohol
• nausea or dizziness medication
• sleeping pills
• cold/flu remedies
• over-the-counter pain medication

What to expect during vestibular testing

ENG:

• This test measures involuntary eye movement (nystagmus) whilst stimulating the subject’s balance.
• Eye movements are measured using an infrared video system.

ECOG:

• This test measures the response to sounds from the nervous system.
• An earphone plays sounds in the ear, whilst an electrode measures the response.

Rotation tests:

• Assesses how the eyes and inner ear are working together.
• Video goggles or electrodes are used to measure eye movements.
• This is either carried out through auto-head rotation, computerised rotary chair or a screening test.

VHIT:

• Special glasses with a camera monitor eye movements.
• Small and quick head movements are evaluated (the vestibulo-ocular reflex).

VEMP:

• Checks if particular vestibular organs and nerves are functioning correctly.
• Responses are measured from muscles in the neck and around the eyes.
• Adhesive skin electrodes are used.
• Sounds are played for a few seconds, and the electrodes record the vestibular response.

What do abnormal results mean from vestibular testing?

If the vestibular system is found to be functioning fine, then other tests will be carried out to determine the cause of the patient’s dizziness. This may be an MRI, blood pressure test, or psychological evaluation.