Electroencephalogram (EEG)

An EEG measures the brain's electrical activity (brain waves). An EEG may be used to diagnose and monitor seizure activity or to help evaluate brain tumors and other neurological conditions.

How to Prepare

Please arrive for this outpatient procedure at the time and location given to you.

The evening before or morning of your appointment, wash and dry your hair, but do not apply any spray, oil, mousse, or cream.

Sleep only four hours the night before this test. Sleeping for only a few hours will help ensure that you fall asleep during the test and enable your physician to study your brain's electrical activity. Unless your CINN physician tells you otherwise, take your regular medication as scheduled. On the day of the test, eat regular meals, but do not consume coffee, tea, chocolate, or other products containing caffeine.

You might receive a sedative to help you relax during this procedure. As a precaution, please arrange for a friend or family member to drive you home.

What to Expect

A technologist will place 20 to 25 small disks (electrodes) on your scalp with a glue-like adhesive. You might be asked to breathe rapidly or look at a flashing light. You will then be asked to lie quietly or sleep, if possible, in a recliner chair while equipment connected to the electrodes records your brain's electrical activity.

An EEG is painless and takes approximately 45 to 60 minutes to complete, although it may last longer.

Additional Instructions

You may resume your normal activities immediately, unless you were given a sedative and are still drowsy. In that case, you will need to rest until you feel ready to resume your regular routine.