Electronystagmography (ENG) testing

By using the most recent diagnostic tests such as electronystagmography (ENG), Aurora Health Care’s team of audiologists can diagnose balance and dizziness conditions such as vertigo.

What is an electronystagmography test?

The vestibular system maintains your balance and spatial orientation, which is the natural ability to understand the direction of objects (forward or backward, right or left and above or below).

ENG testing provides a nystagmus (involuntary eye movements) assessment, checks the functionality of the vestibular (balance) system and helps diagnose certain neurological functions.

How an ENG test works

ENG testing typically involves a series of exercises designed to elicit specific eye movements and provoke symptoms such as dizziness or vertigo. The test typically takes 90 minutes to perform and involves the use of small electrodes.

Your audiologist will attach the electrodes around the eyes to monitor and record the electrical activity of the eye muscles during a series of maneuvers that include:

• Following a visual target with your eyes
• Moving your head into various positions to assess uncontrolled eye movements associated with changes in head position
• Introducing warm or cold air or water into the ear canal to stimulate the inner ear and elicit nystagmus

The electrodes pick up the signals generated by the eye movements during these maneuvers and relay those findings to a computer. The signals are then analyzed to identify the presence and characteristics of nystagmus.

While ENG provides accurate measurements of eye movements, the use of electrodes may introduce some limitations. The electrodes can be sensitive to movement and the setup process may take more time.

What’s the difference between electronystagmography (ENG) and videonystagmography (VNG)?

There are other methods for checking vestibular function, such as videonystagmography (VNG) and rotary chair testing, which may offer similar information but use different technologies.

ENG and VNG evaluate the vestibular system's function by measuring eye movements. However, they differ in the technology used for analyzing these movements.

Why you might need an electronystagmography

ENG is often used to diagnose and evaluate disorders of the inner ear, vestibular nerve and central nervous system. Some common reasons your doctor might recommend an ENG test include:

• Dizziness and vertigo: ENG provides inner ear testing to determine whether the symptoms are related to benign paroxysmal positional vertigo (BPPV), labyrinthitis or Meniere's disease.
• Unexplained balance Issues: If a person is experiencing difficulties with balance without an obvious cause, ENG can be used to assess the vestibular system and identify potential underlying issues.
• Evaluation of nystagmus: Electronystagmography is particularly effective in recording and analyzing involuntary eye movement patterns, which helps your doctor diagnose specific conditions.
• Vestibular assessment: ENG can provide information about how well the vestibular system is functioning. This includes assessing the response to head movements, changes in body position and other stimuli that may provoke nystagmus.
• Monitoring treatment progress: In some cases, ENG testing may be used to monitor the effectiveness of treatments for vestibular disorders.

Preparing for your electronystagmography test

If your doctor recommends having an ENG test, they will provide instructions on how to get ready. Some general guidelines that may help you prepare for an ENG test include:

• Reviewing your medications
• Avoiding caffeine or alcohol before the test
• Don’t wear makeup or jewelry
• Having a ride to and from the testing facility

Risks of an electronystagmography test

There are minimal risks with an electronystagmography test. Some people experience nausea and dizziness. Other risks include:

• Water from the caloric test may cause mild discomfort. If you’ve been diagnosed with a perforated tympanic membrane, you should not do the water caloric portion of the test.
• Neck or back problems may be aggravated by changes in the position needed for testing.

Discuss any concerns with your doctor prior to your test.