Electroencephalogram (EEG)

Need to know

• What happens icon plus

  You'll be asked to sit or lie still while several small sensors are attached to your scalp. These sensors pick up the electrical impulses sent from your brain. As part of the test, your consultant may ask you to breathe deeply, blink your eyes or look at a flashing light. A routine EEG usually lasts for 20 to 40 minutes. Other types of EEG include: - Sleep EEG, which records brain waves while you sleep - Ambulatory EEG, which records throughout the day using a portable device - Video EEG, which films you during the test if you experience seizures Depending on your symptoms or condition, your consultant will recommend the EEG that's right for you.

• How to prepare icon plus

  Your consultant will explain the test to you and answer any questions you may have. They'll let you know if there is anything specific you need to do to prepare, such as avoiding certain medications. If you're having a sleep EEG, sometimes called a sleep-deprived EEG, they'll let you know if and how long you should sleep the night before your test.

• Afterwards icon plus

  If you're having a routine EEG, you should be able to go home right after your test. If you're having another type of EEG, your consultant will let you know what to expect. Your consultant will review your results and let you know what the next steps are for further tests or treatment options.