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Electronystagmography is a test to look at voluntary and involuntary eye movements. It evaluates the acoustic nerve, which runs from the brain to the ears (and control hearing and balance) and the occulomotor nerve, which runs from the brain to the eyes.
Alternative NamesENG
How the test is performedPatches called electrodes (similar to those used with ECG, but smaller) are placed above, below, and to the side of each eye. They may be attached by adhesive or by a band around the head. Another electrode is attached to the forehead.
The electrodes record eye movements that occur when the inner ear and nearby nerves are stimulated by delivering cold and warm water to the ear canal at different times. Sometimes, the test is done using air instead of water. Each ear is tested separately.
When cold water enters the ear, it should cause rapid, side-to-side eye movements called nystagmus. The eyes should move rapidly away from the cold water and slowly back. Next, warm water is placed into the ear. The eyes should now move rapidly toward the warm water then slowly away.
Patients may also be asked to use their eyes to track objects, such as flashing lights.
The electrodes detect the length and speed of eye movements, and a computer records the results.
The test takes about 90 minutes.
Electronystagmography provides exact measurements of eye movements detected by the electrical changes the movements produce. It is more objective than simply watching the eyes after flushing warm or cold water into the ears. It can record behind closed eyelids or with the head in a variety of positions.
How to prepare for the testNo preparation is necessary. Check with your health care provider if you are taking any medications.
How the test will feelThere is minimal discomfort. You may find cold water in the ear uncomfortable. Brief dizziness (vertigo) may occur during the test.
Why the test is performedThe test is used to determine whether a balance or nerve disorder is the cause of dizziness or vertigo.
Your doctor may order this test if you have dizziness or vertigo, impaired hearing, or suspected damage to the inner ear from certain medications.
Normal ValuesDistinct involuntary eye movements should occur after instillation of warm or cold water into the ear canal.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results meanAbnormal results may be a sign of damage to the nerve of the inner ear or other parts of the brain that control eye movements.
Any disease or injury that damages the acoustic nerve can cause vertigo. This may include:
- Blood vessel disorders with bleeding (hemorrhage), clots, or atherosclerosis of the blood supply of the ear
- Cholesteatomaand other ear tumors
- Congenital disorders
- Injury
- Medications that are toxic to the ear nerves, including aminoglycoside antibiotics, some antimalarial drugs, loop diuretics, and salicylates
- Multiple sclerosis
- Movement disorders such as progressive supranuclear palsy
- Rubella
- Some poisons
Additional conditions under which the test may be performed:
What the risks areThere is a small risk associated with the caloric stimulation part of the test. Excessive water pressure can injure a previously damaged eardrum, but this rarely occurs. Caloric stimulation should not be performed if your eardrum has been perforated recently because of the risk of causing ear infection.
ReferencesGriggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 418.
Wiki User
∙ 13y ago
Wiki User
∙ 12y agoElectronystagmography is a test that looks at eye movements to see how well two nerves in the brain are working. These nerves are:
- Acoustic nerve, which runs from the brain to the ears
- Occulomotor nerve, which runs from the brain to the eyes
ENG
How the test is performedPatches called electrodes, are placed above, below, and on each side of your eyes. They may be sticky patches or attached to a headband. Another patch is attached to the forehead.
The health care provider will deliver cold water or air into each ear at seperate times. The patches record eye movements that occur when the inner ear and nearby nerves are stimulated by the water or air. When cold water enters the ear, you should have rapid, side-to-side eye movements called nystagmus.
Next, warm water or air is placed into the ear. The eyes should now move rapidly toward the warm water then slowly away.
Patients may also be asked to use their eyes to track objects, such as flashing lights or moving lines.
The test takes about 90 minutes.
How to prepare for the testNo preparation is necessary. Check with your health care provider if you are taking any medications.
How the test will feelThere is minimal discomfort. You may find cold water in the ear uncomfortable. Brief dizziness (vertigo) may occur during the test.
Why the test is performedThe test is used to determine whether a balance or nerve disorder is the cause of dizziness or vertigo.
Your doctor may order this test if you have dizziness or vertigo, impaired hearing, or suspected damage to the inner ear from certain medications.
Normal ValuesDistinct involuntary eye movements should occur after the warm or cold water or air is placed into your ears.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results meanAbnormal results may be a sign of damage to the nerve of the inner ear or other parts of the brain that control eye movements.
Any disease or injury that damages the acoustic nerve can cause vertigo. This may include:
- Blood vessel disorders with bleeding (hemorrhage), clots, or atherosclerosis of the blood supply of the ear
- Cholesteatomaand other ear tumors
- Congenital disorders
- Injury
- Medications that are toxic to the ear nerves, including aminoglycoside antibiotics, some antimalarial drugs, loop diuretics, and salicylates
- Multiple sclerosis
- Movement disorders such as progressive supranuclear palsy
- Rubella
- Some poisons
Additional conditions under which the test may be performed:
What the risks areExcessive water pressure inside the ear can injure a previously damaged eardrum, but this rarely occurs. The water part of this test should not be done if your eardrum has been perforated recently, because this can lead to an ear infection.
Special considerationsElectronystagmography is a better test than simply watching the eyes after flushing warm or cold water into the ears. It can record movements behind closed eyelids or with the head in a variety of positions.
ReferencesGriggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 418.
Sanders DB, Howard JF Jr. Neuro-otology: laboratory investigations in diagnosis and management of neuro-otological disorders. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 40.
Reviewed ByReview Date: 04/30/2011
Kevin Sheth, MD, Department of Neurology, University of Maryland School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine;David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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What is electronystagmography?
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How does an Electronystagmography work?
Electrodes are placed on the skin around the eye and the individual is subjected to a variety of stimuli so that the quality of eye movements can be assessed
What has the author Alfred C Coats written?
Alfred C. Coats has written: 'Manual of electronystagmographic technique' -- subject(s): Eye, Electronystagmography, Examination, Handbooks, manuals
What tools does a Audiologist use?
Otoscope, typanometer, audiometer, electronystagmography, auditory brainstem response, otoacoustic emmissions, hearing aid programmer/hi-pro, ear cleaning devices/wax removal devices such as a curette or irrigation, electrophysiology equipment, ASSR, immitance and compliance testing for the middle ear
What has the author Charles W Stockwell written?
Charles W Stockwell has written various books on subjects such as personal growth, leadership, and organizational behavior. Some of his notable works include "Unlocking Your Ultimate Success" and "The 5 Keys to Successful Leadership." He is known for providing practical strategies and insights to help individuals and organizations thrive.
Medical Testing: Why Preventative Health Care Is Important?
Medical testing serves two main purposes. It can help to pinpoint the specific cause of an illness, pain or other discomfort or it can help with preventative care. The most common medical test performed in the United States is a blood test. The U.S. Preventive Services Task Force, American Heart Association and American Cancer Association are among organizations touting the benefits of medical testing as a means of preventative health care.Leading Causes of Preventable Death WorldwideHypertensionSmokingHigh cholesterolTobacco SmokingObesityHeart diseaseAbdominal MRIABO Blood TypingAllergy testingAntiglobulin testsBreast biopsyLiver biopsyBlood cultureBone mineral densityBreast ultrasoundCAT scan (body, head and face, spine)Cholesterol and triglycerides testsSpinal CTStool AnalysisMagnetic Resonance Angiogram (MRA)Magnetic Resonance Image (MRI) (of the abdomen, breast, head, knee, shoulder and spine)EEG (Electroencephalography)EKG (Electrocardiogram)EMG (Electromyography)ENG (Electronystagmography)Semen AnalysisLeading Causes of Preventable Death in the United StatesInsurance covers many basic types of preventative care. This includes flu shots, blood tests and most minor medical tests. When more expensive medical tests are ordered by a doctor, it may be more difficult to acquire approval from an insurance company. However, several agencies provide medical testing/screenings at reduced costs or free of charge for those who quality.There are more than 500 common medical tests performed at hospitals and other medical facilities across the country. Some of the most common medical tests currently performed in the U.S. include:Diet, exercise and good nutrition are among the basics of preventative health care. Preventative medical testing is just as important at detecting things that may be going on with our bodies that could lead to potentially troubling medical conditions. In most cases, preventative medical testing detects conditions that are easily treatable with medications.According to the World Health Organization, many diseases can be prevented with early detection through medical testing. Most current health care systems operating in the world are based on responding to acute problems and urgent needs of patients.A recent study found that many health care systems in the United States are now incorporating preventative health care measures and related medical testing into primary care. The United States spends roughly $2.3 trillion on health care each year. According to one estimate, more than $100 billion annually could be saved with preventative health care.
Caloric stimulation?
DefinitionCaloric stimulation is a test which uses differences in temperature to diagnose ear nerve damage.Alternative NamesCaloric test; Cold water calorics; Warm water caloricsHow the test is performedThis test stimulates the inner ear and nearby nerves by delivering cold and warm water to the ear canal at different times. Rarely, the test is done using air instead of water. The person doing the test should examine the ear and especially the eardrum to make sure it is normal before doing the test.One ear is tested at a time.When cold water enters the ear and the inner ear changes temperature, it should cause rapid, side-to-side eye movements called nystagmus. The eyes should move away from the cold water and slowly back.Next, warm water is placed into the ear. The eyes should now move towards the warm water then slowly away.The eyes can be observed visually, but more often this test is done as part of electronystagmography which uses patches called electrodes, placed around the eyes, to detect the movements. A computer records all the results.Ice cold water may be used if there are no responses.How to prepare for the testDo not eat a heavy meal before the test. Avoid caffeine, alcohol, allergy medications, and sedatives at least 24 hours prior to the test, as these can affect the results. (However, do not stop taking medicines without first talking to your doctor.)How the test will feelSome people find cold water in the ear uncomfortable. Brief, but severe vertigo may occur during the test. You may have nausea associated with that feeling. Vomiting is rare.Why the test is performedCaloric stimulation is done to check the acoustic (ear) nerve, which provides hearing and helps with balance. It is also used to test parts of the brain involved in balance.This test may be recommended if you have:Dizziness or vertigoHearing loss that may be due to certain antibioticsCertain types of anemiaPossible psychological causes of vertigoIt may also be done to look for brain damage in persons in a coma.Normal ValuesRapid, side-to-side eye movements should occur when cold or warm water is placed into the ear. The eye movements should be similar on both sides.What abnormal results meanAbnormal results mean there may be damage to the nerve of the inner ear. If the rapid, side-to-side eye movements do not occur even after ice cold water is given, there may be damage to the nerve, the balance sensors of the inner ear, or the brain.Abnormal results may be due to:Atherosclerosisof the blood supply of the earBlood vessel disorders with hemorrhage (bleeding)Blood clotsCertain types of poisoningsCholesteatomaand other ear tumorsCongenital (present at birth) disordersDamage to the ear nerves due to certain antibiotics, antimalarial drugs, diuretics, and salicylatesRubella that damages the acoustic nerveTraumaThe test may also be done to diagnose or rule out:Acoustic neuromaBenign positional vertigoLabyrinthitisMeniere's diseaseWhat the risks areExcessive water pressure can injure a previously damaged eardrum, but this rarely occurs since the amount of water to be used is measured in advance. Caloric stimulation should not be performed if the eardrum is perforated because of the risk of causing ear infection. Caloric testing should not be performed during an acute vertigo episode as it can make symptoms worse.Special considerationsCaloric stimulation is approximately 80% accurate in differentiating nerve damage as a cause of vertigo. Other tests may be required to confirm the diagnosis.ReferencesBaloh R. Hearing and equilibrium. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 454.
Acoustic neuroma?
DefinitionAn acoustic neuroma is a slow-growing tumor of the nerve that connects the ear to the brain. This nerve is located behind the ear right under the brain.An acoustic neuroma is benign, which means it does not spread to other parts of the body or invade the tissue around it. However, it can damage several important nerves as it grows.Alternative NamesVestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumorCauses, incidence, and risk factorsAn acoustic neuroma is believed to occur when there is a defect in a gene that normally prevents tumors from forming. The cause of the genetic defect is not known. However, acoustic neuroma can be linked with the genetic disorder neurofibromatosis type 2(NF2).Acoustic neuromas are relatively uncommon.SymptomsThe symptoms vary based on the size and location of the tumor. Because the tumor grows so slowly, symptoms usually start after the age of 30.Common symptoms include:Abnormal sensation of movement (vertigo)Hearing loss in the affected ear that makes it hard to hear conversationsRinging (tinnitus) in the affected earLess common symptoms include:Difficulty understanding speechDizzinessHeadache Upon waking up in the morningWakes you from sleepWorse when lying downWorse when standing upWorse when coughing, sneezing, straining, or lifting (Valsalva maneuver)With nausea or vomitingLoss of balanceNumbness in the face or one earPain in the face or one earSleepinessVision problemsWeakness of the faceSigns and testsThe health care provider may diagnose an acoustic neuroma based on your medical history, an examination of your nervous system, or tests.Often, the physical exam is normal at the time the tumor is diagnosed. Occasionally, the following signs may be present:DroolingFacial droopingon one sideUnsteady walkDilated pupil on one side only (See: Eyes, pupils different size)The most useful test to identify an acoustic neuroma is an MRI of the head. Other useful tests to diagnose the tumor and tell it apart from other causes of dizziness or vertigo include:Head CTHearing test (audiology)Test of equilibrium and balance (electronystagmography)Test of hearing and brainstem function (brainstem auditory evoked response)Test for vertigo (caloric stimulation)TreatmentDepending on the size and location of the tumor, you and your health care provider must decide whether to watch the tumor (observation) or try to remove the tumor.Many acoustic neuromas are small and grow very slowly. Small tumors with few or no symptoms may be followed. Regular MRI scans will be done.If they are not treated, some acoustic neuromas can damage the nerves involved in hearing, as well as the nerves responsible for movement and feeling in the face. Very large tumors can lead to a buildup of fluid (hydrocephalus) in the brain, which can be life-threatening.Removing an acoustic neuroma is more commonly done for:Larger tumorsTumors that are causing symptomsTumors that are growing quicklyTumors that are growing near a nerve or part of the brain that is more likely to cause problemsSurgery is done to remove the tumor and prevent further hearing loss or other nerve damage.Stereotactic radiosurgery focuses high-powered x-rays on a small area. It is considered to be a form of radiation therapy, not a surgical procedure. It may be used:To slow down the growth of tumors that are hard to remove with surgeryTo treat patients who are unable to have surgery, such as the elderly or people who are very sickRemoving an acoustic neuroma can damage nerves, causing loss of hearing or weakness in the face muscles. This damage is more likely to occur when the tumor is next to or around the nerves.Expectations (prognosis)An acoustic neuroma is not cancer. The tumor does not spread (metastasize) to other parts of the body. However, it may continue to grow and press on important structures in the skull.People with small, slow-growing tumors may not need treatment.Once hearing loss occurs, it does not return after surgery.ComplicationsBrain surgery can completely remove the tumor in most cases.Most people with small tumors will have no permanent paralysis of the face after surgery. However, about two-thirds of patients with large tumors will have some permanent facial weakness after surgery.Approximately one-half of patients with small tumors will still be able to hear well in the affected ear after surgery.There may be delayed radiation effects after radiosurgery, including nerve damage, loss of hearing, and paralysis of the face.Calling your health care providerCall your health care provider if you experience new or worsening hearing loss or vertigo (dizziness).ReferencesBrackmann DE, Arriaga MA. Neoplasms of the posterior fossa. In: Cummings CW, Flint PW, Haughey BH, et al, eds. Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa: Mosby Elsevier;2010:chap 177.Battista RA. Gamma knife radiosurgery for vestibular schwannoma. Otolaryngol Clin North Am. 2009;42:635-654.Sweeney P, Yajnik S, Hartsell W, Bovis G, Venkatesan J. Stereotactic radiotherapy for vestibular schwannoma. Otolaryngol Clin North Am. 2009;42:655-663.
Meniere's disease?
DefinitionMeniere's disease is an inner ear disorder that affects balance and hearing.See also: VertigoAlternative NamesHydrops; Endolymphatic hydropsCauses, incidence, and risk factorsThe inner ear has fluid-filled tubes called semicircular canals, or labyrinths. The canals, along with a nerve in your skull, help interpret your body's position and maintain your balance.Meniere's disease occurs when a part of the canal, called the endolymphatic sac, becomes swollen. This sac helps filter and remove fluid in the semicircular canals.The exact cause of Meniere's disease is unknown. In some cases, it may be related to:Head injuryMiddle ear infectionSyphilisOther risk factors include:AllergiesAlcohol useFatigueRecent viral illnessRespiratory infectionSmokingStressUse of certain medications, including aspirinGenetics may also play a role.About 100,000 people a year develop Meniere's disease.SymptomsSymptoms include:Abnormal sensations of movement (vertigo) Gets worse with sudden movementLasts for a few minutes to several hoursMay come and goDizzinessHearing loss in one or both ears Low frequency noises lost firstExtent of hearing loss may changeNoises or ringing in the ear (tinnitus)Sudden episodes of complete disorientation that causes the person to fall downSweating (may be heavy)Uncontrollable eye movementsVomiting and nauseaThe feeling of dizziness and being off balance generally come in attacks that last from minutes to hours. Other symptoms can last for longer.Signs and testsA neurological examination may show problems with hearing, balance, or eye movement.A procedure called caloric stimulation tests eye reflexes by warming and cooling the inner ear with water. Abnormal results on this test can be a sign of Meniere's disease.Additional tests done to distinguish Meniere's disease from other causes of vertigo may include:Evoked potential studiesElectronystagmographyHead CT scan or head MRI scanHearing tests (audiology/audiometry)TreatmentThere is no known cure for Meniere's disease. The goal of treatment is to reduce pressure in the inner ear and relieve symptoms.Medications, such as antihistamines and anticholinergics, are used but are rarely effective.Water pills (diuretics) may help relieve fluid pressure in the inner ear. A low-salt diet to reduce fluid retention may also help (See: Sodium in diet)Medicines called antiemetics may be prescribed for nausea and vomiting. Symptoms such as dizziness and vertigo may respond to sedative/hypnotics and benzodiazepines such as diazepam.Ear surgery may be required if symptoms are severe and do not respond to other treatment.Hearing aids may be needed for severe hearing loss.Avoid sudden movements that may aggravate symptoms. You may need help walking due to loss of balance during attacks.Avoid bright lights, TV, and reading during attacks, which may make symptoms worse. Rest during severe episodes, and gradually increase activity.Avoid hazardous activities such as driving, operating heavy machinery, climbing, and similar activities until 1 week after symptoms disappear.Expectations (prognosis)The outcome varies. Meniere's disease can often be controlled with treatment. Recovery may occur spontaneously. However, the disorder may be chronic or disabling.ComplicationsInability to walk or function due to uncontrollable vertigoHearing loss on the affected sideCalling your health care providerCall for an appointment with your health care provider if symptoms of Meniere's disease, such as hearing loss, ringing in the ears, or dizziness, occur or worsen.PreventionThere is no known prevention for Meniere's disease, but prompt treatment of ear infection and other related disorders may be helpful.ReferencesSchessel DA, Minor LB, Nedzelski J. Meniere's disease and other peripheral vestibular disorders. In: Cummings CW, Flint PW, Haughey BH, et al, eds. Otolaryngology: Head & Neck Surgery. 4th ed. Philadelphia, Pa; Mosby Elsevier; 2005:chap 142.
