Skip to content
My WebMD Sign In, Sign Up

Brain & Nervous System Health Center

Font Size

Electronystagmogram (ENG)

An electronystagmogram (ENG) measures normal eye movement and involuntary rapid eye movements called nystagmus. It also checks the muscles that control eye movements. ENG checks how well the eyes, inner ears camera.gif, and brain help you keep your balance and position (such as when you change from lying down to standing).

ENG is done to help see whether there is damage or a problem in how the inner ear, brain, or nerves connecting them work. These problems may cause dizziness, vertigo, or loss of balance.

Nystagmus occurs normally when the head is moved. But nystagmus without moving your head or nystagmus that does not go away may be caused by conditions that affect the inner ear, brain, or the nerves connecting them.

During ENG, electrodes are attached to the face near the eyes to record eye movements. The movements are recorded on graph paper. A series of recordings is done.

  • Baseline recordings are taken with your head at rest.
  • More recordings are done:
    • While you move your head up and down, left and right.
    • While you look at a moving object.
    • After warm or cold water (or air) is placed inside your ears.

Why It Is Done

An electronystagmogram (ENG) is done to:

  • Find where the problem is in the inner ear, brain, or nerves connecting them that is causing dizziness, vertigo, or a loss of balance.
  • Find any damage to structures or nerves in the inner ear, brain, or nerves connecting them.

How To Prepare

For 2 to 5 days before the test, you will be asked to stop taking:

Your doctor may ask you to eat a light meal or not eat for 3 to 4 hours before the test, because the test can cause nausea and vomiting.

Do not wear facial makeup during the test so the electrodes can attach to the skin.

If you normally wear glasses, contact lenses, or hearing aids, bring them to the test.

If you have a neck or back problem, tell your doctor, so your neck and back will be protected during the test.

How It Is Done

An electronystagmogram (ENG) may be done in a hospital or in a doctor's office by a doctor or hearing specialist (audiologist).

Before the test begins, your eyes and ears will be checked. Any earwax in your ear canal will be removed.

Five electrodes will be attached with a special paste to your face. You will be in a dark room for the test. The test may have six parts.

  • To find the right settings for the measuring tool, you will follow a moving point of light with only your eyes. You should not move your head during this part of the test.
  • Readings will be taken with your eyes closed. You may be given a mental task to do, such as an arithmetic problem, during this part of the test. Readings will be taken while you look straight ahead and to each side.
  • Readings will be taken while your eyes follow the back-and-forth movement of a pendulum.
  • Readings will be taken while you follow a series of moving objects out of your line of vision. As each object leaves your line of vision, you will be asked to look immediately at the next moving object.
  • Readings will be taken while you move your head from side to side and up and down. You may be asked to move your body (as well as your head) into different positions.
  • Near the end of the test, your eye movements may be recorded while cool and warm water is placed inside your ears. In some cases, warm and cool air may be blown gently into your ears instead of using water. This part of the test is called the caloric test and may be done without using electrodes near your eyes. The caloric test is not done if you have a perforated eardrum, because water used in the caloric test can get into the middle ear and lead to infection. The caloric test can be done with air instead of water, but if the eardrum is perforated, the caloric test may not be done at all.

The test may take 60 to 90 minutes.

WebMD Medical Reference from Healthwise

Last Updated: November 30, 2011
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

Today on WebMD

nerve damage
Learn how this disease affects the nervous system.
senior woman with lost expression
Know the early warning signs.
 
Close up of eye
12 culprits that affect your ability to focus.
medical marijuana plant
What is it used for?
 
senior man
Article
brain research briefing
Article
 
Syringe
Article
Vaccine and needle
VIDEO
 
mans hands on laptop keyboard
Article
brain illustration stroke
Slideshow
 
most common stroke symptoms
Article
Parkinsons Disease Medications
Article