Electroencephalogram (EEG)


An electroencephalogram (EEG) tracks your brain waves to detect unusual activity or diagnose neurological conditions

Enquiries & Appointments

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Our Electroencephalogram (EEG) locations

The Harley Street Clinic

The Harley Street Clinic

35 Weymouth Street W1G 8BJ London
The Shard Outpatients

The Shard Outpatients

The Shard, 32 St Thomas Street SE1 9BS London
London Bridge Hospital

London Bridge Hospital

27 Tooley Street SE1 2PR London
The Wellington Hospital

The Wellington Hospital

8A Wellington Place NW8 9LE London

What is an EEG?

An EEG is a painless test to record the electrical activity in your brain and help pinpoint the source of symptoms like seizures or memory loss.

It's commonly used to diagnose and monitor conditions including epilepsy, dementia, sleep disorders and brain tumours or trauma.

Need to know

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.

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.

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.