Please read this information carefully before coming in for your Motor Evoked Potential (MEP) test.
What is an MEP?
MEP stands for motor evoked potential. It is a non-invasive procedure. It is a recording of the electrical signals that assess the function of the motor pathways in the brain, through the spinal cord and into the limbs. It looks at how these pathways are functioning rather than taking images as you would see in a scan.
Why do an MEP?
If you have been experiencing problems with your coordination, weakness, or other changes in limb function you may be referred for a MEP.
What happens during an MEP?
Once you are settled comfortably on the couch, your skin will be wiped with alcohol gel and small sticky recording pads will be placed over muscles in the hands and feet to record the responses.
A plastic paddle will then be held over your head by the physiologist. You will hear a clicking noise when the magnetic pulse from the coil stimulates the brain and this will then cause a response to be recorded from the fingers or toes, causing them to twitch in time to the pulses.
A series of these pulses are given, and the responses collected and stored on the computer.
These pulses can feel briefly uncomfortable but there are no known side effects once stimulation has finished.
The test takes around 60 minutes.
Once the recording has finished all the sticky pads will be removed and the skin wiped clean.
Preparing for the test
- You must arrive with clean, dry hair free from grease, gel, wax or other hair products. You may wish to bring a comb or brush to tidy your hair after the test.
- Please wear clothes which allow easy access to you lower arms and legs.
- Continue to take all regular medication as normal before the test.
- You will be asked if you understand this information and whether you consent to the test before we start. At your appointment, you are welcome to ask the neurophysiologist doing the test to give you further information or to explain more about the procedure.
When will I get my results?
You will not get your results straight after the test or see a doctor on the day as the MEP needs to be fully analysed.
A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.
Contact details
This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.
Your responsibility as a patient
Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient.
What if I am unwell or need to change my appointment?
If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.
If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.
What if I don’t attend?
We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.
© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003741
