Evoked potential study (1734)

Your child has been scheduled for an Evoked Potential Study in the Neuroscience Center at Children’s Wisconsin Clinics Building: 
on_____________________ at _________ am / pm

Please stop at a Welcome desk in the Clinics building for a badge and directions. 
Please arrive for your appointment at least 15 minutes before the scheduled time.

What is an evoked potential study?

A stimulus is used to get a response (evoke) from the nerves. This response is called an impulse (potential). This test measures and records how long it takes nerves to respond to the stimulus.
There are three types of this test to study your child’s nerve pathways. 

• Visual. This will study the visual pathway of your child’s eyes. This takes 1 to 1½ hours. The stimulus is a flash of light.
• Auditory. This will study your child’s hearing pathway from the ears to the brain. This takes 1 to 2 hours. The stimulus is a sound.
• Somatosensory. This will study nerve pathway from your child’s arms and legs to the brain. This takes 1½ to 2 hours. The stimulus is an electrical pulse on the hands or feet.
  If your child needs to have more than one test done, it may take 2 hours or more.

What needs to be done before the test?

• Wash your child’s hair the night before the test. Do not put anything else on your child’s hair or scalp. This includes oils, conditioners, mousse, cream rinse or hair spray.
• Your child should get a full night of sleep before the test. 
• Your child should eat a good meal before coming to the hospital. The day before the test, do not let your child eat foods or drink liquids that have caffeine.  This includes cola, coffee, tea and chocolate.
• Keep giving your child medicine as prescribed. 

How is it done?

Small electrodes will be placed on your child’s scalp, neck, limbs or back depending on which test is being performed. The electrodes record electrical impulses by the nerves. These are held in place with a clear glue or paste. When the electrodes are removed, the glue or paste will be washed off. There is no need to shave or cut your child’s hair. 

Your child will not receive any shots. During the somatosensory test, your child will feel a tingling feeling on the skin when the nerve is stimulated.

How will I get results of the test?

The results of the test will be sent to the doctor who ordered the test in about 7 to 10 business days. Your doctor will call you to explain the results.