My Evoked Potential Examination

What is an Evoked Potential investigation?

This is a test of the function of various parts of your brain and spinal cord. A recording of the electrical activity of your brain is made whilst you are given a stimulus. This test is carried out by an experienced technician under the supervision of one of the Consultant Neurophysiologist.

How is the investigation carried out?

The stimulus given may be a visual image, such as the movement of a checkerboard pattern on a TV screen, or a sound through headphones or a small electrical pulse on your skin. The choice of these is made by your doctor, depending on the type of symptoms you have. Small metal plates are attached to your skin in various places using a form of soluble glue, and you will be asked by the technician to relax and concentrate on the stimulus. The rest will be carried out several times to ensure the result we get is reliable. The electrodes are then removed with a solvent.

Will the investigation do me any harm?

No. Although the equipment used is electrical, it is designed so that no harmful shocks can be given to you.

Will it hurt?

If your test involves the electrical pulses on the skin, these are at worst, mildly uncomfortable. All other types of the test are completely pain free. Anything that you find too uncomfortable will not be continued.

Will I get the result immediately?

The data from your test is passed to one of the medical staff of the department for reporting, and the result should be with your referring doctor within a few days.

Can I ask questions?

The technician will be very happy to answer your questions, and indeed may wish to talk to you about your symptoms as the test progresses. However, they will not be able to tell you the result of the investigation until it has been reviewed by one of the Consultants in the department.

Will I have to wait long?

We try to tailor our appointment times so that there is a minimal wait in the department. However, on rare occasions you may have to wait whilst we accommodate an emergency case. The waiting room is equipped with papers and magazines and our staff will try to make your wait as pleasant as possible.

If you have found this leaflet helpful or if you feel there are other questions that we should have addressed, please let a member of the staff know.