Magnetoencephalography (MEG) testing is performed in 1043 Wisconsin Institutes for Medical Research (WIMR). Parking in this area is limited. We have a nearby parking stall and can provide you with a parking permit when you arrive.

The purpose of the test is to utilize MEG, along with EEG, to identify areas of the brain that produce epileptiform activity. You are already familiar with EEG, which records tiny electric signals that are produced naturally by the brain. MEG is similar to EEG, but it records magnetic signals and can localize brain activity more accurately than EEG. The MEG sensors do not emit anything. They passively detect naturally occurring magnetic signals; therefore, the test is perfectly safe. The testing time varies depending on the frequency of occurrence of epileptiform activity, such as interictal spikes. In order to obtain a good result, it is essential that we record many such events. Some patients show only normal activity during the test and in these cases we are unable to obtain a result at all. You should plan to be here for 4-6 hours.

The test is performed inside a shielded room in order to screen out environmental magnetic interference. We will first attach EEG electrodes so that the EEG can be recorded along with the MEG. We will then have you lie down on a bed and position your head between two sensors. Typically, we reposition the sensors several times during the test. MEG is painless and non-invasive, but you do need to lie very still for long periods of time. If you need a break, let us know. You will be monitored by a video camera and an intercom allows us to hear you.

Before You Come

Before scheduling an appointment with us, please tell us if you have orthodontic braces or bars, a permanent retainer, surgical plates or pins, or any other metal in your body. These produce large magnetic interference and may disqualify you from MEG testing. Also, please tell us if you are claustrophobic because you will need to lie in a small, closed room during the test.

The chances of getting a good test are increased if you are sleep deprived. You should sleep less than half of your usual sleeping time the night before the test.

When you arrive in our lab, we will ask you change into scrubs because most clothing contains metal, which can produce magnetic interference. Please do not wear eye makeup or hair styling products such as hair spray or gel, as these often contain small amounts of metal. Even small pieces of metal, such as the hooks on your bra, are a problem. Body piercing needs to be removed.