Electronystagmography
What Is Electronystagmography?
Electronystagmography (ENG) is a type of stroboscopy used to measure the voluntary and involuntary eye movements in order to assess the function of the vestibular system in the ear. Vestibular system includes hospitals, vestibulocochlear nerve, and brainstem pathways. This test is mostly used to diagnose various disorders such as vertigo, gaze abnormalities, and bilateral vestibulopathy.
Preparation for Electronystagmography:
Your physician may ask to avoid certain medications, such as sedatives, tranquilizers, muscle relaxants, or alcohol 12–24 hours prior to the test. Additionally, it is recommended to refrain from smoking for approximately one–three hours before the test.
Procedure of Electronystagmography
During the ENG, electrodes are placed on your forehead and behind your ears. The electrodes are connected to specialised wires that are attached to an ENG machine. The test can be done in dark both, partially lit room or in a brightly lit room. The patient is asked to look in different directions and then the response of the eye movement can be recorded on the ENG machine.
Types of Electronystagmography
- VEMP (Vestibular Evoked Myogenic Potential)
- VHIT (Vestibular Hyperventilation Induced Nystagmus Prep)
- Dix-Hallpike Test
- Caloric Testing
- Postural Control Test
- Rotational Chair Testing
Risks Associated with Electronystagmography
Though ENG is a simple and non-invasive test, it is not completely free from risks. It may cause certain complications, such as nausea, headache, dizziness, and lightheadedness in some people. Additionally, it may also cause discomfort due to the uncomfortable positioning of the patient's head and eyes.
Why Electronystagmography is done?
The ENG test is an important clinical tool, which can diagnose both central and peripheral imbalance in the vestibular system. It is especially useful in detecting the cause of vertigo or dizziness, which can be a side effect of certain medications, a symptom of an infection, or a sign of stroke. Additionally, it can also be used to diagnose other eye movement disorders such as nystagmus, spasm, and strabismus.
When to Schedule an Electronystagmography Test?
The physicians can schedule this test in case of any of the following possible conditions:
- Vertigo
- Gaze Abnormalities
- Bilateral Vestibulopathy
- Nystagmus
- Spasm
- Strabismus
- Meniere's Disease
- Hearing Loss
- Motion Sickness