VNG Balance Evaluations
Vertigo and Imbalance
Vertigo, dizziness, and balance problems can be life altering. For many people it can affect their ability to do even the simplest daily tasks. If you are experiencing vertigo or balance issues, your doctor may refer you for a balance evaluation. There are several tests that evaluate different aspects of your balance system.
What is a VNG Evaluation?
VNG stands for videonystagmography, which is a series of tests that evaluate the health of the balance portion of your inner ear and your central motor system function. VNG testing can possibly uncover the root cause of your vertigo, dizziness, or balance issues, allowing your doctor or audiologist to treat it appropriately and effectively.
What Tests Will Be Performed?
The VNG consists of several different tests including:
Ocular Mobility Test: This test checks your ability to follow visual targets. You will attempt to follow targets with your eyes while an object is jumping, moving slowly, moving quickly, or standing still. Inability to track objects properly could indicate central or neurological problems or possibly an issue with the vestibular system.
Dix-Hallpike and Positional Tests: These tests evaluate the positional portion of your balance organ otherwise known as the semi-circular canals. You will be asked to move your head and body into different positions. We will be watching for abnormal eye movements (nystagmus) or vertigo triggered by the varying position changes.
Caloric Test: This test can determine if you have a weakness in one or both balance organs. Your ears will be stimulated with cool and warm air. In some cases, water may be used. The cooling and warming affect of the air or water may make you dizzy, but this symptom typically will only last a short time.
Throughout the test you will be wearing goggles. The goggles have cameras inside which focus on your eyes and record the eye movement. The test can last up to 1 ½ hours in duration.
Preparing for VNG Testing:
Due to the nature of the test, there are some preparations you will need to make prior to your evaluation. Please read all instructions carefully! Failure to follow instructions may result in cancellation of your test when you arrive.
- Dress comfortably.
- Bring someone with you to drive you home, as you may feel a little dizzy after the test.
- Do NOT eat, drink (including coffee or other caffeinated beverages) or smoke for 4 hours prior to testing. Water is acceptable up to 30 minutes prior to testing.
- Do NOT wear EYE MAKEUP.
- Certain medications affect the results of the VNG. In order to prevent this from happening it will be necessary for you NOT to take any of the following mediations 48 hours (2 days) prior to your appointment (please contact us if you have questions about the statement above).
- Sleeping pills ( including PM version of Tylenol and/or Excedrin)
- Tranquilizers (Valium, Xanax)
- Antihistamines (Benadryl, Actifed, Chlor-Trimeton, Dimetane, Claritin, etc.)
- Barbiturates or Narcotics (Vicodin, codeine, Demerol, Dilaudid, Percodan, Phenaphen, etc.)
- Alcoholic Beverages
- Anti-Dizzy Pills (Migral, Marezine, Antivert, Meclizine, Dramamine, Ruvert, etc.)
- Muscle Relaxants
- Prescription Migraine medications.
You may continue taking medications for High Blood Pressure, Seizures, diabetes. If you have concerns as to whether you need to stop taking mediations or have any questions regarding the VNG, please feel free to contact our office at 970-221-3372.
VEMP (Vestibular Evoked Myogenic Potential):
A VEMP is a special test for evaluation of dizziness. It checks the saccule organ which is part of the balance organ in the inner ear. During the non-invasive VEMP examination, small recording surface electrodes are taped to the neck and shoulders of the patient, and a small ear phone is placed in one ear. Sounds are presented to one ear while the patient’s head is held in a certain orientation. The test is not uncomfortable and takes about 30 minutes.
The ECoG measures the electrical responses from the cochlea in the inner ear and auditory nerve. The cochlear summating potential (SP) and whole nerve action potential (AP) of the auditory nerve are measured and their rations are compared. An ECoG is currently used for objective identification of Meniere’s disease.
For this test small portions of the skin are cleaned with an abrasive lotion. An electrode is taped to the forehead, clip electrodes are placed on the ear lobes and a gold foil foam electrode is inserted in each ear. A series of loud “clicks” are heard and the electrophysiological responses are recorded onto a computer for analysis. The patient task is to be relaxed with eyes closed and active participation is not required. The test takes approximately one hour.