What is Electronystagmogram (electronystagmography)(ENG)
Electronystagmogram is a procedure to measure the eye movements that occur when your eyes move rapidly from side to side or up and down (nystagmus). These movements happen without any effort (involuntary response).
During an ENG, these eye movements are monitored and recorded to check whether they occur in response to different changes in the environment (stimuli).
It is normal to have nystagmus in response to certain stimuli, such as changing your head position. If nystagmus occurs unexpectedly or does not stop, this can indicate a problem with the inner ear or various parts of the brain, including the nerve that runs from the ear to the brain (acoustic nerve).
You may have this procedure to check for problems of the nervous system or the inner ear that are caused by a tumor, an infection, low blood supply, medicines, injury, or other conditions.
Your health care provider may also recommend this procedure to help determine the cause of dizziness or vertigo. Vertigo is the sensation that you or your surroundings are moving when they are not.
Tell a health care provider about:
- Any allergies you have.
- All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
- Any problems you or family members have had with anesthetic medicines.
- Any blood disorders you have.
- Any surgeries you have had.
- Medical conditions you have, especially ear problems such as previous trauma or damage to your eardrum.
What are the risks?
Generally, this is a safe procedure. However, problems may occur, including:
- Dizziness.
- Nausea.
- Infection.
- Injury to the eardrum.
What happens before the procedure?
- Ask
your health care provider about:
- Changing or stopping your regular medicines. This is especially important if you are taking diabetes medicines or blood thinners.
- Taking medicines such as aspirin and ibuprofen. These medicines can thin your blood.Do nottake these medicines before your procedure if your health care provider instructs you not to.
- Follow
your health care provider’s instructions about eating or drinking
restrictions.
- You may be instructed not to eat solid food before the procedure. This will decrease the chance of vomiting.
- You may be instructed not to drink caffeine or alcohol for 24–48 hours before the procedure.
- Do notput makeup on your face before the procedure. Makeup may interfere with the electrodes.
What happens during the procedure?
- You will sit or lie down on an exam table for the procedure.
- Your ear canals will be checked. Ear wax will be removed if necessary.
- Electrodes will be taped to your skin near and around your eyes.
- Your
eye movements will be measured:
- Before any stimulation is applied (calibration test).
- While you look at and follow a visual target (tracking test).
- While you are moved into various positions (positional testing).
- While cold and warm water or air is put into your ear canals (caloric testing).
This procedure may vary among health care providers and hospitals.
What happens after the procedure?
- You may need to spend time in a recovery area until any nausea or dizziness goes away.
- After you have fully recovered, follow your health care provider’s instructions about returning to your normal activities.
