How should I prepare?

  • You may eat normally and take your seizure medicine or any other medicines as usual, unless you will be having sedation or anesthesia during the procedure.
  • Sometimes they may ask you not to eat or drink for a certain number of hours before the test if you will be given a special dye or contrast during the test. 
  • Some people become anxious during the test, especially if they don't like being in small or enclosed spaces. Talk to your doctor and the scheduling people in advance about this. You may be given a medicine to help you relax for the test. 
  • People who would have trouble lying still during the test may be given a medicine to help them sleep. If this is needed, the person will meet with the radiology team and an anesthesia doctor ahead of time. 
  • Wear loose, comfortable clothing without metal fastenings such as zippers or clasps because metal will interfere with the test.
  • Do not wear jewelry, hairspray, makeup, a hearing aid, or any removable dental work.
  • If you have any metal in your body—plates, clips, or screws from surgery; an intrauterine device (IUD); or pieces of metal left in a wound, for instance—or if you are pregnant, you should tell your doctor or nurse ahead of time and tell the MRI technician before the test begins.
  • If you have a pacemaker, you cannot have an MRI because the test may damage it. The same rule applies if you have metal fragments in your eyes because the magnet may cause them to move. 

Can people with a vagus nerve stimulator have an MRI?

People with an implanted vagus nerve stimulator will need to have special precautions.

  • They can only have an MRI of their head, using a special MR machine with a transmit and receive head coil. At present, you can not have an MRI of other body parts. 
  • There may be some other limits on the type of MR scan you can have so always talk to the radiology and epilepsy team before an MRI is scheduled. 
  • The vagus nerve stimulator needs to be turned off before your MRI. You will need to see your doctor or nurse who programs the VNS before the MRI test so they can turn the stimulator off.  After the MRI, you will need to see them again to turn the VNS back on. 
  • Many centers will refuse to perform an MRI scan on anyone with a stimulator in place, so talk to your doctor first. You should have the test done at a place that is familiar with VNS and MRIs. 

What will happen when I get there?

  • The technologist at the MRI center will direct you to the special self-contained room where the MRI machine is located. This person will ask you to lie down on a cushioned table, where a device will be placed around your head. Then you will be moved into the magnet.
  • The technologist will leave the room but will stay in constant contact with you throughout the entire exam. (See pictures of the MRI procedure.)
  • When the MRI scan begins, you will hear a muffled thumping sound that will last for several minutes, while the pictures are being taken.
  • Earplugs or music will be provided so that the noise doesn't sound so loud. Try to relax -- you can even take a nap.
  • Do your best to lie as still as possible, since any movement during this time will blur the picture.
  • Other than hearing the sounds, you should experience no other sensation during scanning.
  • After the scanning is complete, usually in about 30 minutes, the technologist will return to help you off the table and then you may go home.
  • Your doctor will discuss the results of the test with you over the phone or at your next scheduled visit.

What if my child can't lie still that long?

Because they need to remain perfectly still for a fairly long time, younger children may require sedation (or in some cases, general anesthesia) to complete an MRI. Older children or adults who are developmentally disabled or emotionally or cognitively impaired also may need either general anesthesia or sedation. You should discuss the need for sedation or anesthesia with your doctor in advance so that proper arrangements can be made.


Authored By: 
Ruben Kuzniecky, MD
Joseph I. Sirven MD
Reviewed By: 
Joseph I. Sirven MD
Patty Obsorne Shafer RN, MN
Thursday, August 22, 2013