What to expect about Electroencephalography (EEG)

What to expect for an EEG (electroencephalogram) study:

An EEG study is a noninvasive test that detects electrical activity in your brain using small

electrodes attached to your scalp. An EEG can determine changes in brain activity that is

useful in diagnosing brain disorders especially epilepsy and other disorders of brain

function.


Routine EEG

The test involves placing a cap on your head which is connected to 21 small disc electrodes

overlying various locations on your scalp. Recording times will vary from 30- 90 minutes.

You will be asked to do a couple activation activities during the study, including brief

hyperventilation and looking at strobe lights. During most of the study, you will simply rest

quietly in a recliner and attempt to fall asleep. Afterward, you will want to wash your hair to

remove any residual electrode paste.


To prepare for an EEG, please do the following:

  • Eating is permitted prior to your EEG
  • Avoid any caffeine for at least 12 hours prior to your test
  • Continue to take any medications prescribed by your doctor or advanced practice
  • provider (we will ask you to bring a list your medications with to your EEG)
  • Please arrive with clean, dry hair
  • Do not use any hair styling products, including oils, prior to the test
  • Feel free to bring a light blanket to help you relax and sleep.
  • Family members or companions are not allowed in the room during EEG testing to
  • reduce the likelihood of noise and promote sleep.

Sleep-Deprived EEG

This test is similar to a regular EEG, as described above, except that you will be asked to

achieve 4 fewer hours of normal sleep or as directed by your provider prior to your exam

time. Do not eat or drink anything containing caffeine between midnight and the time of your

test. A sleep-deprived EEG takes about 1-2 hours.

Ambulatory EEG

This test allows you to move about within your home, possibly capturing one of your events

or offering a much longer sampling of your brainwave activity. You will want to arrive with

clean, dry hair and no styling products as above. Setup for the test takes approximately

one hour and requires a technician pasting 25 small electrodes onto the surface of the scalp

using a sticky, water-soluble paste. The wires are covered with netting and head wrap. After

set up, you will need to go immediately home and remain in your home for the duration of

the test. You will be given an EEG case and some video cameras to set up within your

home. Our remote EEG monitoring team will be in contact with you if we are experiencing

technical difficulties with your study. You will be able to move about your home throughout

the study and asked to keep a diary of any events you should experience. You will be

responsible for immediately returning your equipment at the end of your study for removal of

your electrodes and analysis of the data by the epileptologist.