An EEG is the recording of the electrical activity produced by the brain. An ambulatory EEG continually records this activity during your normal daily routine. It is not painful and has no after-effects.
What is an ambulatory EEG?
An EEG is the recording of the electrical activity produced by the brain. An ambulatory EEG continually records this activity during your normal daily routine. It is not painful and has no after-effects.
Why have I been asked to have this test?
We want to try and record the events which you have recently reported to your consultant/epilepsy nurse. You have probably already had a routine or sleep EEG which only monitors your electrical activity for up to 2 hours. We often do not record a typical event in this time. Ambulatory EEG can be used to increase the chances of recording an event or to understand how many events you have over a period of time. Even if you are not having frequent events it can help to review your electrical activity over a longer period of time.
Before the appointment
You should have an appointment letter with this leaflet. Since we want to record your typical events, if you think a different appointment date or time would be more beneficial please contact the department on 0113 3926855 to rearrange the date.
Preparation for the test
- You should eat and drink as normal before the test.
- Continue to take medications as prescribed
- It is essential that we can get access to your scalp. Please avoid top knots, backcombing etc Hair should be clean and dry. Please do not use any hair products for example, gel or hairspray.
- If you have a weave or complex braids or have any doubts about your hair please call the department before your appointment as it may affect the test.
- Please wear clothing that has buttons, or a loose neck, as taking your clothes off over your head may disturb the electrodes.
- You may want to bring a hat to wear so the electrodes are not in view when you return home.
- Bring a list of current medications
How is it done?
The test is performed by a physiologist and takes approximately 1 hour to 1.5 hour to attach and set up the equipment. The test involves attaching 23 electrodes to the surface of the head.
The area beneath the electrodes is rubbed with a cotton bud and the electrodes are applied using water soluble paste and a special medical glue. This glue ensures that the electrodes are firmly applied. A head bandage can be used to secure the electrodes in younger patients. Some minor skin irritation may occur. Please make staff aware if you have a skin complaint or allergy. These are then connected to a small recorder box, which is placed in a bag, worn on a belt around the waist. The box will record your brainwaves for a 24 hour period.
You can then return home and continue the day as usual. During the test you will be asked to keep a diary recording your actions, such as any symptoms, seizures or events and the times you went to bed etc. Please record as much detail as possible about any warning signs, length of the attack or seizure and any triggers you feel might have been involved. Keeping a log of this information is a vital part of the test. This will be explained fully by the physiologist during your visit.
It is strongly advisable that you have someone who knows your events with you during the test set up and at home. If you do have any typical events during the test they can attend to you and help you complete the diary.
- You must keep the bag attached to you around the waist at all times, even when you are in bed.
- You are not able to have a shower or bath at all during the test. The equipment must not get wet.
- Though you should behave normally, try and avoid repetitive physical movements such as running on a treadmill.
- Please avoid chewing gum for prolonged periods as this interferes with the recording.
- You will be given a time to return the following day to have the equipment removed.
- The electrodes are removed using a solution which dissolves the glue. Small traces of glue will remain in your hair and it will feel greasy. You will need to wash your hair with shampoo when you get home.
Though unlikely, if you have any problems with the glue after you leave please do not hesitate to contact the department who can help and advise you with this.
24 Hour Video ambulatory EEG
This is an ambulatory test with the addition of a video camera which will film you during the test. This is useful for certain types of events, such as night time events or for patients who have no one to witness their events.
The neurophysiology consultant will decide if this is a more suitable test for you.
If so a staff member will attempt to talk to you over the phone before your appointment so you are fully informed of the details of the test. You have the option to decline the video but it is beneficial in trying to understand and diagnose your events.
If you are having this test you will need to read the 24 hour ambulatory EEG instructions above. In addition you will be given a camcorder at your appointment. You will be given clear instructions on how to use it and where best to keep it once you are home. It is best to keep it filming at all times (except bathroom visits) both when awake and asleep so we can record your behaviors and any events which may occur in the 24 hour period. The camera will also record sound so we can hear what happens during an event.
Back to topOther factors to consider
Whoever is in the room may also be filmed. When you consent to the test it means you consent to the physiologist and the consultant to view the video with sound. This means they can see and hear whoever is recorded on the camera.
This is a specialized piece of medical equipment which is your responsibility once you leave the department until you return it to the hospital. This includes when you are traveling to and from your home.
The camera is taken home in a protective case. It is bulky so please consider your transport to and from the hospital. Once home you must not take the camera out of the house. It is advisable to have a friend or family member with you for the test period as they can help with maintaining the diary and help with carrying and setting up the equipment. They can also help to make sure you are on camera if you have an event.
You will need to return the camera when you come back the following day.
We welcome feedback about our services. Please tell a member of staff if you felt this service was good or otherwise.
Further Information about EEG’s is available from numerous organisations including
UK Epilesy Helpline:
Epilepsy Action
Freephone:
If you have any queries or questions regarding this information, please contact the Neurophysiology Department on 0113 392 6855
Large print copies are available on request from the department on the number above.
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