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Sleep Deprived EEG (Electroencephalogram) Patient

What is a Sleep Deprived EEG?

EEG stands for Electroencephalogram. This is a recording of the electrical activity of the brain. Recording this information will help your consultant in the diagnosis and management of your complaint or condi- tion. An EEG is used to investigate a number of different conditions, most commonly being blackouts or seizures.

A sleep deprived EEG is a recording of your brain waves following a period of no sleep and may provide the doctors with additional infor- mation.

A Clinical Physiologist will perform the test and staff in training may be present during your investigation, this will be explained at the time of your appointment and consent for this will be discussed with you

What should I do before the test?

Stay awake for 24 hours prior to the test

You should ensure you have a someone available to accompany you to your appointment. It is essential that you do not drive yourself to/from the hospital. You are welcome to bring a friend or relative to accompany you to your appointment.

Please wash your hair and do not use any hair products such as gel or hairspray. If you have extensive hair extensions/weave these will need to be removed prior to your EEG.

You should take your medication as normal and please bring along a written list of your current medication

What will happen during the test?

The Clinical Physiologist will explain the test, answer any questions you may have and obtain a clinical history from you.

The Clinical Physiologist will mark some points on your scalp with a soft pencil. After rubbing these points with a gel, 23 small electrodes will be placed using a sticky paste.

The majority of the test will be performed with your eyes closed. You will not feel anything during the recording.

A video will be taken of you during the recording, this will allow any move- ments or episodes you may have to be matched up with the EEG record- ing. A video will be taken of you during the recording, this will allow any movements or episodes you may have to be matched up with the EEG re- cording. If you do not wish for the video to be undertaken please let the Clinical Physiologist know on arrival to the appointment

During the test you may be asked to

  • perform a breathing exercise: This involves taking deep breaths for up to three minutes.
  • look at a flashing light: The physiologist will instruct you to look into a strobe light which will flash on and off at different speeds

Consent will be discussed at your appointment for these portions of the re-cording

For the majority of the recording you will be given the chance to fall asleep. You will be rested back comfortably, covered with a blanket and the lights will be dimmed to encourage you to fall asleep.

The test will take around 90 minutes in total.

What will happen after the test?

After the recording, the electrodes will be taken off with warm water. Your hair will feel sticky following removal of electrodes and require washing when you return home.

You will not be told any results following the test. The results will go back to your Consultant in approximately 2-3 weeks.

Are there any risks?

In some people there is a very small chance that being sleep deprived, the breathing exercise or the flashing light could result in a seizure or clinical event. These risks are fully explained during the test and your consent is re- quired for these parts.

In the very unlikely event that you do have an epileptic seizure or blackout you would be required to inform the DVLA and your driving licence would be suspended.

If you are unable to attend this appointment , have any specific requirements or questions please ring 0151 556 3416 as soon as possible.

Patient co-operation is required for the duration of the test; if due to a learning disability you feel more time is needed, please contact the department .In addition we can also provide a visit to the depart- ment in advance of the appointment for patients who may require it to familiarize yourself with the surroundings and staff.

We can provide this information leaflet in larger fonts or audio format via email if required, please phone the number above

We welcome feedback about our services. Following the test we would be grateful if you would take a Patient Satisfaction Survey away with you to fill in and send back to us freepost.

Further information about EEG is available from numerous organisations Including:

  1. UK Epilepsy Society Helpline: 01494 601 400 or visit
  2. Epilepsy Action Helpline (Freephone): 0808 800 5050 or visit
  3. The Brain Charity, Norton Street, Liverpool L3 8LR, 0151 298 2999 or visit

This information can be translated on request or if preferred an interpreter can be arranged for additional information regarding these services please contact the Patient Experience Team on 0151 556 3090

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