The purpose of the ENG (electronystagmography) is to determine whether or not dizziness may be due to inner ear disease. There are four main parts to the ENG. The calibration test evaluates rapid eye movements. The tracking test evaluates movement of the eyes as they follow a visual target. The positional test measures dizziness associated with positions of the head. The caloric test measures responses to warm and cold water delivered to the ear canal through a small, soft tube.
Before the test begins, electrodes are attached to the face near the eyes to detect eye movements. The signals from the electrodes are recorded on graph paper. ENG involves a series of recordings.
The comparison of results obtained from various subtests of ENG assists in determining whether a disorder is central or peripheral. In peripheral vestibular disorders, the side of lesion can be inferred from the results of caloric stimulation and, to some degree, from positional findings.
While ENG is the most widely used clinical laboratory test to assess vestibular function, remember that normal ENG test results do not necessarily mean that a patient has typical vestibular function. ENG abnormalities can be useful in the diagnosis and localization of site of lesion; however, many abnormalities are non-localizing; therefore, the clinical history and otologic examination of the patient are vital in formulating a diagnosis and treatment plan for a patient presenting with dizziness or vertigo.
The ENG test is the gold-standard for diagnosis of ear disorders affecting one ear at a time. For example, the ENG is excellent for diagnosis of vestibular neuritis. The ENG is also useful in diagnosis of BPPV, as well as unilateral or bilateral vestibular loss. The calibration and tracking tests are intended to diagnose central nervous system disorders, such as cerebellar degenerations. These tests are generally insensitive compared to an examination by a neurologist or an MRI scan. ENG, however, is much less expensive than an MRI in most institutions.
3 days before the test, you will be asked to stop taking:
1.Medications that reduce vertigo
2.Sedatives and tranquilizers
3.Drinks containing alcohol
4.Stimulants, including foods that contain caffeine (such as coffee, tea, cola, and chocolate)
Your may be advised to eat only a light meal or not eat for several hours before the procedure, because the procedure may cause nausea and vomiting.
Do not wear facial makeup during the test because it can interfere with attaching the electrodes 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 condition, tell your health professional before the test so that precautions can be taken to prevent worsening of your problem.
A typical ENG usually takes approximately 30 minutes.
|3265 W Sarazens Cl
Memphis, TN 38125
|Ph: (901) 763-1234
|Make An Appointment TODAY!|