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EEG Testing: A Patient's Guide

By Department of Neurology, Hospital for Special Surgery
  1. What is EEG Testing?
  2. What to expect during EEG testing?
  3. Does EEG testing hurt?
  4. What are the preparations for the EEG Test?
  5. What to expect during the appointment


What is EEG Testing?

EEG or Electroencephalography is a test used to study brain wave patterns. It can provide your doctor with information about the nature of the type of difficulties you’ve been experiencing.

What to expect during EEG testing?

A specially trained EEG technician will first measure your head with a tape measure. He will then rub certain spots on your scalp lightly and place about 20 gold disc electrodes with a light cream on those spots. You will be asked to recline in a chair or lay in a bed for about half an hour while a special machine records your brain waves. During the sessions you may be asked to breathe in and out deeply and lights may be flashed before while your eyes are closed.

Does EEG testing hurt?

The EEG does not involve needles or electrical stimulation of any kind. It is a completely painless procedure.

What are the preparations for the EEG Test?

  • Tell your doctor if you are taking any medications. Certain medications (such as sedatives and tranquilizers, muscle relaxants, sleeping medications, and medications used to treat seizures) can affect your brain’s electrical activity. Patients on medication should take their usual medication on the day of the test.
  • Since a deep breathing exercise (hyperventilation) may be performed, please inform the technologist of any hearing or respiratory issues, sickle cell anemia, recent head trauma, or stroke.
  • Avoid foods that contain caffeine (such as coffee, tea, cola, and chocolate) for at least eight hours before the test. Otherwise, you can eat and drink as usual 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 clean 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. This test cannot be performed on patients with non-removable weaves or wigs.
  • After the EEG, the cream and discs will be removed by the technologist. Small reddened areas may be noted on the scalp which will disappear in a short period of time.
  • Allow 60-120 minutes for this procedure.

What to expect during the appointment:

  • The EEG is completely painless
  • Small, disc-shaped cups will be placed on your head to record the electrical activity of the brain.
  • The discs will be secured with a small amount of paste and tape/gauze, all of which will be washed away quickly after the test is complete.
  • The technologist will ask the patient to relax and attempt to go to sleep.
  • The EEG will be read by the physician after you leave the office. You should expect results via phone or mail within five business days.

If you have any questions regarding the EEG procedure or wish to cancel/reschedule, please call 212.606.1047.


Department of Neurology
Hospital for Special Surgery

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