Tests and Treatments Electroencephalogram (EEG) An Electroencephalogram (EEG) is a brain wave test that detects abnormalities in the electrical activity of the brain. This helps us to diagnose: Seizure disorders Head injuries Sleep disorders Causes of unconsciousness Other neurological conditions Despite what you might have heard elsewhere, an EEG does not treat or cure illness, read your mind, give you an electric shock or measure your IQ. What to Expect A registered technologist performs EEGs. The technologist applies electrodes (small metal disks) to your scalp with an adhesive gel or paste. The gel looks and smells like clear nail polish. The paste is odorless and looks like toothpaste. This is a painless procedure and the gel or paste is easily removed after the test. The electrodes pick up your brain's electrical activity and carry it by wires to a computer that amplifies the signals and stores them. Later, a trained neurophysiologist interprets these signals. The neurophysiologist sends a report to your doctor, who will discuss the results with you. This whole process takes about a week. How to Prepare The most important way to prepare for your EEG: Don't sleep. We record a portion of your EEG during natural sleep, so you should get less than half your normal sleep the night before the test. In some cases, patients must stay awake all night. Don't sleep during the ride to the hospital. If you know you won't be able to fall asleep naturally during the EEG, let us know in advance and we'll arrange to administer a mild sedative. If you are scheduled for a carotid baseline test, which is given to patients when they're wide awake, sleep deprivation isn't required. In addition, you should: Plan on two hours for the EEG. Wash your hair either the night before or the morning of the EEG. Do not use grease, hair spray, oils or conditioners. Eat normally. But avoid caffeine coffee, tea, chocolate, soft drinks, and alcohol for 24 hours prior to the test. Take your usual medications as prescribed by your physician. Have someone drive you to and from the test. It's unsafe for you to drive a vehicle for several hours after the test because you will be sleep deprived and may have been sedated. If you take public transportation, you should not travel alone.