Neurodiagnostics
Early and accurate diagnosis is vital to properly treating a neurologic disorder. Gundersen Lutheran's Neuroscience Center offers a variety of neurodiagnostic procedures to help our expert physicians develop the proper treatment plan.
For further information on any of these tests or to schedule an appointment, call the Neuroscience Center at (800) 362-9567, ext 59000 or (608) 775-9000.
Learn more about:
What is an Electromyogram?
An EMG measures and records muscle and nerve responses to accurately diagnose and treat nerve and muscle diseases. It will be performed by a physician in one of the EMG labs in the Neuroscience Center. There are two parts to the procedure.
 (1) Nerve Conduction Study
The technologist will tape small electrodes on the skin and briefly apply a mild electric stimulus to the area being studied. Nerve stimulation causes a tingling sensation and brief twitching of specific muscles. This test measures how fast your nerves conduct or carry signals.
(2) Electromyography
During the EMG, the physician analyzes electric activity in muscles by inserting a fine needle electrode into selected muscles. Needle insertion may cause mild temporary discomfort. The needle is not used for injection, and no shocks are given. The physician can determine whether the muscle is working normally by watching patterns of electrical activity on a screen and listening over a loudspeaker. The needle is discarded after each use.
Specific Precautions
You do not need to do anything special to prepare for this test, except to keep skin free of all lotions or oils. Eat, drink, and take medications as you normally do. Be sure to let the physician performing the EMG know if you take a blood thinning medication, such as Coumadin.
Results of Procedure
The neurologist/physiatrist interprets study results and sends them to the physician who referred you for this procedure. With this information, your regular physician will be better equipped to coordinate further care and treatment.
Learn more...
What is an Electroencephalogram?
 An EEG, or brain wave test, is a method of recording the electrical activity of the brain. It is mainly used to study the function of brain cells. An EEG does not produce pictures, only waveforms. It also is the most accurate method known for diagnosing epilepsy and other brain conditions.
Our EEG lab accredited
Gundersen Lutheran’s EEG Lab was accredited in September 2005 by the Laboratory Accreditation Board of the American Board of Registration of Electroencephalographic and Evoked Potential Technologists (ABRET). It was the first in the state and only the fifth in the country to achieve this status. After evaluating management, technical standards, and quality of output, this independent accrediting agency confirmed that Gundersen Lutheran’s EEG lab meets strict national guidelines and delivers excellent diagnostics. EEGs from this lab may be interpreted by physicians anywhere.
 As further proof of excellence, this lab has been a clinical teaching site for the EEG/EP/Sleep program at Western Wisconsin Technical College for many years. Because the quality of electroneurodiagnostics achieved here is well known, even on a national level, graduating technologists are highly sought after.
Preparing for your EEG
Please arrive for your EEG with clean hair. We ask that you do not apply any gel or hairspray. Wear comfortable clothing as you may be asked to sleep for part of the test.
Whether or not your EEG is ordered routine or sleep deprived you need to follow these instructions:
- Take your medication as directed by your physician. (Please bring a list of your current medications.)
- Unless otherwise instructed for another test, you may eat as you normally would. If allowed, please eat within two hours of the EEG.
If your physician wants you to sleep during the EEG, you may be asked to be awake for part of the early morning or 24 hours prior to your EEG.
- Follow these guidelines for sleep deprivation:
- Less than 1 year of age - get up four hours prior to normal wake up time.
- 1-3 years old - get up six hours prior to normal wake up time.
- 4-16 years old - get up eight hours prior to normal wake up time.
- Over 16 years of age - get up 24 hours prior to the EEG.
- No caffeine after 6 p.m. the night before the test.
- We recommend you have a driver bring you to your appointment and take you home after the test is done.
Your doctor may order a video EEG in an attempt to capture a spell on camera. This can last up to six or more hours. For this reason we would like you to bring your lunch or money to buy lunch. Sometimes if a number of spells are captured early on in the recording, the test will be ended before six hours. This is at the discretion of the doctor.
The EEG
 In the lab you will be lying in a bed while a technician applies a series of metal disks called electrodes to your scalp. These electrodes are applied with glue, which is dried with compressed air. Once applied, the electrodes are filled with a conductive gel through a blunt tipped syringe. This is a noninvasive procedure. You will feel a slight rubbing on your skin at this time. This gel sits on the surface of your skin and helps conduct your brain activity to the electrode.
During the actual recording, you will be asked to lie quietly in the bed. The technician will ask you to do the following:
- Relax.
- Open and close your eyes.
- A three to five minute deep breathing exercise.
- Possibly fall asleep.
- Look at a series of flashing lights.
The entire EEG can last anywhere from one to three hours. If your doctor has ordered a video EEG, it will be longer. Once the test is finished, the technician will remove the electrodes by dissolving the glue. At home, wash your hair to remove any remaining glue or gel.
If your child is having an EEG, please bring along a favorite toy, book, or blanket. This will help keep him or her calm during the test. There are usually TVs in the rooms. We do ask that you remain present during the test for the child’s comfort.
Learn more...
What is Evoked Potential Testing?
Evoked potential testing measures how well the sensory nerves conduct messages to the brain. While being stimulated in various ways, sensory nerve pathways are monitored. Measurements are taken at various landmarks on the body as the stimulation passes by. The stimulation’s destination is the brain. Every landmark on the body is represented by a waveform. The doctor looks to see how fast that message reaches each landmark. How quickly or slowly the messages reach their destination helps the doctor pinpoint the problem you are having.
Evoked Potentials (EPs)
Prepare for your test as instructed. Please arrive on time with clean hair and skin. Wear comfortable clothing. A hospital gown will be provided if needed. Depending on how many tests your doctor has ordered, you may be here for 30 minutes to four hours. Once the test is over, you will be able to return to your normal daily routine.
During Your Test
Testing is done in a quiet room. The technician will explain how your test or tests will be done. All of the tests involve placing small disks with attached wires called electrodes to your body. The placement is determined by the test that will be done. The electrodes will be applied with either glue or tape. These electrodes record the response from your brain and nerves.
Visual Evoked Potential (VEP)
First the technician will apply five electrodes to your scalp. Next, a patch will be placed over one of your eyes. There will be a checkerboard screen placed a few feet in front of you. You will be asked to gaze at the middle of the screen as the checks reverse back and forth from black to white. A number of trials will be done on each eye. Please bring any glasses or contacts that you use.
Brainstem Auditory Evoked Potential (BAEP)
The technician will apply two electrodes to your scalp and one electrode to each ear lobe. You will then lie down on a bed while wearing headphones. In one ear you will hear a clicking sound and in the other a constant noise, like static. A number of trials will be done for each ear.
Somatosensory Evoked Potential (SSEP)
Your doctor may order this test for either your arms, legs or both. Electrodes will be placed on your scalp, spine, arms, or legs. While you are lying on a bed, the technician will apply a mild electrical current to the nerves in your wrists and ankles. You may feel your muscles twitch. Please know this test will not harm you. Again, a number of trials must be done on each extremity.
Learn more...
Computerized tomography or computer assisted tomography (CT or CAT scan)
A CT or CAT scan is a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat and organs. CT scans are more detailed than general x-rays. CT scans also minimize exposure to radiation. In conventional x-rays, a beam of energy is aimed at the body part being studied. A plate behind the body part captures the variations of the energy beam after it passes through skin, bone, muscle, and other tissue. While much information can be obtained from a regular x-ray, a lot of detail about internal organs and other structures is not available.
Learn more about CT of the brain or learn more about CT of the spine...
Magnetic resonance imaging (MRI)
An MRI is an advanced way to take pictures of the inner brain. It is harmless, painless test and uses a combination of a large magnet, radiofrequencies, and a computer to produce detailed images. An MRI is performed with the patient lying in a small chamber for about 30 minutes. The MRI machine is a large, cylindrical (tube-shaped) machine that creates a strong magnetic field around the patient. This magnetic field, along with a radiofrequency, alters the hydrogen atoms' natural alignment in the body. Computers are then used to form 2-dimensional images of a body structure or organ based on the activity of the hydrogen atoms. Cross-sectional views can be obtained to reveal further details. MRI does not use radiation, as do x-rays or CT scans.
Learn more...
Transcranial Doppler (TCD)
The painless transcranial doppler test uses sound waves to look at major blood vessels in the brain. A microphone is placed on different areas of the head to view the blood vessels.
Neurosonography
The painless neurosonography uses ultra high frequency sound waves to analyze blood flow and blockage in the blood vessels in or leading to the brain.
Cerebral spinal fluid analysis (spinal tap or lumbar puncture)
A spinal tap, also called lumbar puncture, is done to measure the amount of pressure in the spinal canal and/or to remove a small amount of cerebral spinal fluid for testing. This test is used to check for bleeding, hemorrhage, infection or other disorders of the brain, spinal cord and nerves. During this test, the lower back is numbed with local anesthesia and a special thin needle is placed into the space that contains the spinal fluid. The amount of spinal fluid needed to diagnose the specific problem is removed and the needle withdrawn. This test may cause some discomfort.
Learn more ...
|