Sleep deprived EEG - Adult (no sedation)

Sleep EEG (Electro-encephalogram) - ADULT

What is an EEG examination?

A sleep EEG (electro-encephalogram) is the recording of electrical activity produced by the brain whilst you sleep.  It will help your doctor in making a diagnosis.  A sleep EEG is useful as it obtains different information to the routine EEG, as brainwave patterns change during sleep.  The appointment takes approximately two hours and the results will be sent to the referring GP/clinician and are usually available within seven days.

How is the test performed?

A physiologist will measure your head and apply a minimum of 25 small discs using a sticky paste.  Once in place a bandage may be used around your head to hold all the discs securely.  The lights will be dimmed, and you will be asked to lie down on a bed. The setup procedure is not painful, and you will not feel anything whilst the EEG is being recorded.  The recording time is usually an hour.  After the test the discs are removed, small residues of paste may be left in your hair which will wash out with shampoo. 

A digital video recording will be made during the EEG recording.  This enables the doctor to compare your brainwaves with your movements and behaviour during the EEG.  However, the test can be performed without the video if you prefer.  We will ask for your permission to use the video at the beginning of the test.

How do I prepare for the test?

You need to be sleepy for the test.  The night before the recording you should try to remain awake all night.  We ask that you get out of bed and perform an absorbing task like some housework.  Please be aware that if you were to stay in bed you could easily fall asleep again.

Please ensure your hair is clean and free from hairspray and oils, and wear loose fitting, comfortable clothing. 

If you are taking medication please continue to take it and bring a list of your medication with you.  You may continue to eat meals as normal.

It is helpful, where possible, to attend with someone who has witnessed any seizures or clinical events under investigation in order to gain a good description of them.

Please do not have drinks that contain caffeine, e.g. coffee, tea and cola, or stimulant drinks on the day of your test.

Are there any risks?

For some people sleep deprivation can increase the possibility of you having an attack.  If you have any questions regarding sleep deprivation, please contact the department and request a conversation with a physiologist.

We recommend you do not have a bath without someone in the house because you may still be drowsy.