Frequently Asked Questions

FAQs

Our doctors and staff care about getting you accurate answers in a prompt and courteous manner. If you are looking for immediate assistance, please Contact Us. Read frequently asked questions about the following services:

EMG/NCV  |  EEG  |  VNG  |  Sleep Studies

Electromyography/Nerve Conduction Study (EMG/NCV)

What is Electromyography/Nerve Conduction Study (EMG/NCV)?
Electromyography/Nerve Conduction Velocities (EMG/NCV) tests are neurological studies that examine and measure nerve and muscle function. These tests are essential in diagnosing problems related to the nerves and muscles.


Why is it necessary?
EMG/NCV studies are the only tests that can evaluate nerve function in order to determine if nerve or muscle damage exists. The test results will assist your doctor in establishing a plan of treatment specific to your needs.


How is the test administered?
Depending on which area is being tested, you may be asked to lie down or sit upright. During the NCV portion of the test, adhesive electrodes will be placed over specific areas on the extremities and small electrical impulses are administered to the skin overlaying the nerve. The impulses are a part of the test and are harmless. During the EMG portion of the exam, a tiny pin electrode is placed into the surface of specific muscles in the affected extremities to measure electrical activity.


How do I prepare for the test?
Visit the patient information page for instructions.


Who will be performing the EMG/NCV?
It is the policy of NeuroDiagnostic Laboratories as well as the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) that only board certified Neurologists and Physical Medicine & Rehabilitation physicians perform the EMG portion of the test. A trained technologist may assist the physician in performing the NCV portion of the test.


What restrictions and/or side effects should I expect?
There are no restrictions relative to activities before or after the test. There are no side effects from the test.


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Electroencephalogram (EEG)

What is Electroencephalography (EEG)?
Electroencephalography (EEG) is a painless diagnostic procedure which gives information about how the brain functions. EEG testing monitors electrical signals coming from various parts of the brain. An EEG machine then magnifies these signals so that information can be recorded into a computer system.


Why is it necessary?
EEG testing is used as an aid to physicians in diagnosing a number of neurological conditions, most commonly epilepsy and seizure activity. It is the best test to monitor the brain’s electrical activity during both wakefulness and sleep. It is considered the gold standard in diagnosing certain abnormalities and assists your doctor in establishing a plan of treatment specific to your needs.


How is the test administered?
EEG testing involves the placement of recording electrodes over numerous places on the scalp to record and monitor electrical brain activity while at rest. In addition, certain procedures may be done to observe how your brain responds to different forms of stimulation. You may be asked to breathe deeply, look at a bright flashing light, or may be asked to fall asleep. This is a noninvasive test, and the diagnostic technologist is monitoring you throughout the entire procedure.


How long will the test take?
The EEG test typically takes about 90 minutes depending on the complexity of the case. It is imperative to arrive 30 minutes early for your appointment in order to ensure adequate test time.


How do I prepare for the test?
Visit the patient information page for instructions.


Who will be performing the EEG?
Highly trained diagnostic technologists specializing in neurological testing administer all EEG tests. It is the policy of NeuroDiagnostic Laboratories that only Neurologists read and interpret EEG testing results. Our physicians work closely with the test-administering technologists to ensure precise and accurate results for each patient.


What restrictions and/or side effects should I expect?
There are no restrictions relative to activities before or after the test. However, in some sleep deprived EEG tests it is recommended that transportation be provided to and from the testing facility. EEG testing is very safe and well monitored, and at no time is any electrical current put into your body. There are no side effects from the test.


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Videonystagmography (VNG)

What is a Videonystagmography (VNG)?
Videonystagmography (VNG) is a series of non-invasive tests used to determine the cause of dizziness or balance disorders. Because small eye movements are associated with inner ear and brain functioning, VNG testing can determine if and/or where an abnormality exists. Only through the use of sophisticated medical testing equipment can these eye movements be monitored and interpreted. Since vision helps you maintain balance, measuring the direction and amount of eye movement will indicate if there are any weaknesses in your balance system.


Why is it necessary?
VNG testing is now considered by most physicians to be the most sophisticated and accurate test for diagnosing balance abnormalities, and helps rule out other more serious medical conditions. The test results are the best way to assist your doctor in establishing a plan of treatment to fit your specific needs.


How is the test administered?
During a VNG test, a pair of hi-tech video goggles with infrared cameras is worn around the eyes. The technologist may then ask you to follow specific directions while wearing the goggles. You may be asked to follow moving lights, look from one point to another, make rapid postural changes, and have cool or warm air placed in the ear canal to stimulate the inner ear. The small cameras record the eye movement and display them on a computer screen. This allows the examiner to see how the eyes move, helping in the assessment of the balance health system.


How long will the test take?
The tests typically take only 45-60 minutes depending on the complexity of the case. It is imperative to arrive 20 minutes early to ensure adequate test preparation and test time.


How do I prepare for the test?
Visit the patient information page for instructions.


What sensations will I experience?
On occasion during the test some patient’s systems may become momentarily exaggerated. You may become dizzy, nauseated, and/or weak. Care will be given to insure you will not fall down and are able to walk after the test. These temporary symptoms usually last less than 5 minutes, and the level of severity of these symptoms depends on the reason for your test. If you are concerned about not being about to drive afterwards, please make arrangements for someone to transport you home.


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Sleep Studies

What are sleep studies?
Sleep studies are observations of the stages of sleep and the problems that interfere with proper sleep including obstructive sleep apnea or neurological dysfunctions such as narcolepsy and epilepsy.


Why is it necessary?
Studies have found poor quality of sleep is a major factor in:

  • Hypertension
  • Heart Disease
  • Depression
  • Stroke
  • Weight Gain
  • Diabetes
  • Hormone Levels
  • Productivity
  • Memory
  • Sexual Dysfunction

How is the test administered?
Sleep studies are administered while sleeping in a controlled laboratory environment designed to look like a bedroom or a nice hotel room. Patients will be fitted with electrodes and sensors to monitor brain waves, heart function, respiration rate, blood oxygen level, eye movement, body position, leg movement, chin movement, and snoring. This will indicate the level, quality and quantity of sleep.


How long will the test take?
The different tests will vary in length, but normally they are performed at night while sleeping and last from a minimum of 6 to 8 hours depending on the findings and patient’s schedule. If an individual’s normal sleep cycle is to sleep during the day and work during the night then the study will be performed during his/her sleep cycle.


How do I prepare for the test?
Visit the patient information page for instructions.


What types of physicians perform EMG/NCV testing?
It is the policy of NeuroDiagnostic Sleep Centers as well as the American Board of Sleep Medicine (ABSM) that only physicians boarded in sleep medicine, and have been trained or completed a fellowship in sleep medicine, interpret and supervise sleep studies. A highly trained and certified polysomnographer will assist the doctor by administering the test to the doctor’s specific requirements.

NeuroDiagnostic Sleep Centers’ doctors are board certified in neurology and sleep medicine. Most often sleep disorders (other than obstructive sleep apnea) are neurological in natural, which makes us well qualified to handle all sleep cases.


What restrictions and/or side effects should I expect?

  • Do not drink coffee, colas, or teas the day of your test (no caffeine).
  • Do not apply lotions or moisturizers to your skin before the test (we will be applying electrodes and sensors to your skin).
  • Do not take any sleep medication prior to the test, but please bring sleep medication with you.

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