NPH (Neurophysiological) Testing

Here you can find information on our testing procedures:

EMG/NCV

What is an EMG/NCV

Electromyography/Nerve conduction velocity.
     This test gives information on the health and function of the nerves and the muscles they control. It can be used to determine whether numbness and/or loss of muscle strength are caused by an underlying nerve or muscle disease process. It is usually performed on the arms or legs.

Test Instructions for EMG/NCV

  1. Be sure that no creams or lotions are used on the day of the test.

  2. If you have not been here before, please arrive thirty minutes before your appointment time to register.

  3. You may be asked to change into a gown.

  4. This is a two part test. The first part (NCV) is done by our technician. The technician will have you sit down and will apply three electrodes on the body part being tested. Using a stimulator, small shocks will be administered that cause a quick, mild tingling sensation.

  5. This part of the test takes approximately fifteen minutes for each extremity that is tested.

  6. The second part (EMG) is done by our physician. The physician will have you sit or lie down for this part of the test.

  7. This part of the test takes approximately thirty to forty-five minutes.

Procedure:

     For the first part (NCV), the technician will use a stimulator to administer small electrical shocks to the nerve. Several nerves may be tested with small shocks that cause a quick, mild tingling sensation. How the nerve responds will be recorded as a graph. The NCV potion of the study reveals how well the body’s electrical signals are traveling to a nerve.

     For the second part (EMG), the physician will insert a needle electrode through the skin into the muscle being tested. You will be asked to contract the muscle in some way. The electrical activity produced during the test is displayed as waves on an oscilloscope. This activity may be heard on a speaker as a loud pop. The presence, size and shape of the waves indicate the ability of the muscle to respond to nerve stimulation and can help diagnose nerve or muscle damage.

Evoked Potential Tests

What are Evoked Potential (EP) Tests?

     Evoked potentials are tests that examine how information travels through nerve pathways through the spinal cord and/or brain. There are three types of EP tests - somatosensory evoked potentials, visual evoked potentials, and brainstem auditory evoked potentials. Your physician may order one or all of these tests.

     The Brainstem Auditory Evoked Potential (BAEP) measures how information travels from the ear through the auditory pathways of the brainstem.

     The Somatosensory Evoked Potential (SEP) is also referred to as a Somatosensory Evoked Response. This test measures how sensory information travels through the nervous system to the brain with stimulation of the arm or leg.

     The Visual Evoked Potential (VEP) is also referred to as a Visual Evoked Response. This measures how information travels from the back of the eyes through the nervous system to the visual lobe of the brain.

Test Instructions for Evoked Potential Test.

  1. Be sure that no creams or lotions are used on the day of the test.

  2. You will be asked to remove all jewelry. You may want to leave your jewelry at home. If not, it can remain in the room with you.

  3. If you have not been here before, please arrive thirty minutes before your appointment time to register.

  4. You may be asked to change into a gown.

Procedure

       The Visual Evoked Potential (VEP)
     Three electrodes are placed on the head. You will be asked to sit in front of a small monitor. You will be asked to stare at a moving picture, testing each eye individually. The technician will record the responses of your optic nerve in the form of a graph. This test is painless and lasts fifteen minutes.

       The Brainstem Auditory Evoked Potential (BAEP)
     Four electrodes are placed on the head. The technician will place headphones over your ears. Each ear is tested individually. You will recline and will listen to clicking noises. No response is needed from you. The technician will record the responses of your auditory brainstem in the form of a graph. This test is painless and lasts thirty minutes.

       The Somatosensory Evoked Potential (SEP)
     This test is performed on either the upper or lower extremities. Several electrodes are placed on the extremities being tested and on your head. You will be reclined and the technician will then apply a stimulator that will create a mild tingling sensation to the wrists or ankles. The responses will be recorded in the form of a graph. This test lasts thirty minutes for either the upper or the lower extremities.

EEG/Sleep Deprived EEG

What is an EEG?

Electroencephalogram.
     An electroencephalogram (EEG or brain wave test) is a noninvasive procedure used to detect and record brain cell activity.

     Because normal brain waves have recognizable frequencies and amplitudes, variations or abnormalities in brain waves may be helpful in evaluation of various conditions including:

  • Attention deficit disorders (e.g., ADHD)

  • Seizure disorders (e.g., epilepsy)

  • Tumors or abscesses in the brain

  • Head injury

  • Encephalitis and other inflammatory diseases

  • Cerebral hemorrhages

  • Cerebral infarct (stroke)

  • Sleep disorders

  • Migraines (in some cases)

  • Hallucinations

  • Syncope (loss of consciousness)

  • Vertigo

Test Instructions for EEG

  1. Be sure your hair has been washed and dried. Do not use any conditioners, hair sprays, mousse, or any oil based products.

  2. Do not have any braids or hair weaves.

  3. If you have not been here before, please arrive thirty minutes before your appointment time to register.

  4. The EEG technician will have you sit down and will measure your head with a measuring tape.

  5. The technician will then use a red marking pencil to note exactly where the EEG electrodes need to be put.

  6. The areas on your scalp where the electrodes will be placed are washed with a special gel.

  7. The electrodes are tiny metal discs that are filled with a special paste. The electrodes are covered with a white gauze pad.

  8. The electrodes are connected to cables that lead to the machine that records your brain’s activity. You do not get “a shock” from this test.

  9. EKG(electrocardiograph) leads will be placed on your chest.

  10. Getting prepared for the test takes about twenty minutes.

Procedure

     The technician will begin the recording. You will be asked to open and close your eyes several times. A flashing light will go off for several minutes while you have your eyes closed. You will be asked to breathe in and out real fast, for about three to four minutes. If you are drowsy, the technician will let you rest quietly for about twenty minutes and then the test is finished. The technician will take off the electrodes and lightly wipe your hair. You will need a complete shampoo once you are home.

     The total time to complete this test is approximately one hour.

Sleep Deprived EEG

     If your doctor has ordered a sleep deprived EEG, you should not have any sleep the night before the test. For children, have them stay awake an extra two to three hours before normal bed time and then awaken them two to three hours earlier than normal. Please do not eat or drink anything with caffeine 12 hours prior to your appointment.


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