Outpatient Electroencephalogram (EEG)

An electroencephalogram (EEG) is a safe and painless test that measures and records the electrical activity of your brain by using sensors (electrodes) attached to your head and connected by wires to a computer. The computer records your brain's electrical activity on the screen or on paper as wavy lines. Certain conditions, such as seizures, can be detected by observing changes in the normal pattern of the brain's electrical activity.


  • Tell your doctor if you are taking any medications. Certain medications (such as sedatives and tranquilizers, muscle relaxants, sleeping medications or medications used to treat seizures) can affect your brain's usual electrical activity.
  • Avoid foods that contain caffeine (such as coffee, tea, cola and chocolate) for at least 8 hours before the test.
  • Your hair should be clean and free of sprays, oils, creams, lotions and other hair preparations. Shampoo your hair and rinse with clear water the evening before or the morning of the test. Do not apply any hair conditioners or oils after shampooing. Do not braid or tease the hair.
  • Before the EEG, small metal discs will be attached to the scalp with special paste.
  • After the EEG, the paste and electrodes will be removed by the technician. Small reddened areas may be noted on the scalp, which will disappear after a short period of time.
  • Allow an hour and a half for this procedure.
  • You may be asked to stay awake the night before the test because it can enhance abnormalities.