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EEG Examination

What is an EEG Examination?

EEG is the abbreviation of Electro-encephalogram, which is the recording of electrical activity produced by the brain. It can help the doctor to make a diagnosis.

How is it done?

The physiologist will measure your head.  A minimum of 23 leads are then attached to your scalp using a sticky paste. Your heartbeat will also be recorded by attaching two leads to your shoulders. It will take 15-20 minutes to attach the leads to you. You will be asked to lie on a couch for the recording. The recording takes 20 to 30 minutes. During that time you will be asked to relax and to follow instructions, such as to open or close your eyes. You will not feel anything. During the recording you may be asked to do some deep breathing for up to 3 minutes. This may cause some tingling of the hands and toes and may make you a little light headed – this is normal and will pass quickly. 

You may also be asked to watch a strobe light, this is a light that flashes on and off at different speeds. This is particularly important if you have seizures caused by flashing lights. However, rarely the light can trigger a seizure; if you appear to be sensitive the physiologist will stop the flashing light. We will ask for your permission to use the strobe light at the beginning of the test. 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 start of the test. There will be some sticky paste in your hair after the test. We will wipe most of it out before you leave but there will be some residue. This will wash out with shampoo.

How do I prepare for the test?

Please ensure your hair is clean and free from hairspray and oils. Continue to take your usual medications as normal. Please bring a list of your medications with you. You may eat and drink normally before the test.


What happens if I have a seizure during the test?

You will be looked after until you are well enough to go home. It is very unlikely that the investigation will cause a seizure, but if it does, and you hold a driving licence, you will be obliged to inform the DVLA (as for all attacks), this may affect your ability to hold a driving licence.

How long will I have to wait?

You have been given a specific appointment time and patients are usually seen on time. It is important that you arrive on time. Please allow plenty of time for parking. This test takes up to 60 minutes to complete.

When will I get the results?

The results are sent to the doctor that referred you for the test and are usually available within seven days.


Neurophysiology Department  01422 222976

If you have any concerns or questions please speak to one of the Clinical Physiologists on the above number.