Ambulatory EEG

Introduction

This leaflet is designed to give you some information about the investigation for which you been referred. We hope it reassures you. We have a team experienced in these investigations and you will have the chance to discuss further questions or concerns before the start of the investigation.

Consent

We need your consent for any procedure or treatment beforehand. Staff will explain all the risks and benefits before they ask for your consent. If you are unsure about any aspect of the procedure or treatment proposed, please do not hesitate to ask for more information.

What is an electroencephalogram (EEG)?

The brain works by electrical signals that can be recorded as waveforms (brainwaves) by small discs (called electrodes) positioned on the scalp. These brainwaves are sent to a computer and the resulting EEG is read by a healthcare scientist and doctor. EEG can help your medical team get information about brain activity during events currently being experienced or the state of the brain in general.

What is an ambulatory EEG?

This test records over a longer period of time, usually either 24 hours or 48 hours, and takes place at home whilst you carry on with everyday tasks. You will have two appointments for this test, one for applying the equipment and one for removing the equipment.

Why am I having an ambulatory EEG?

There are many reasons for having ambulatory EEG. The most common reason is to capture an event and see if there are any changes in brain activity. Sometimes the recording is useful to find out about brain activity in sleep.

What do I need to do before having the equipment applied?

• Please continue taking any prescribed medication.
• Please let us know if you have any skin sensitivities or allergies during this appointment, especially any latex allergies.
• It is important that your hair is clean using shampoo and conditioner, making sure to avoid all additional hair products.
• It is also helpful to wear loose fitting clothing (ideally something with buttons up the front) to avoid anything being pulled over the head whilst changing at home.

Where is the equipment applied?

Neurophysiology have two departments. One of these can be found on level 3 of the Main Outpatients building and the other is located in Clinic 33 of the Addenbrooke’s Treatment Centre. Please check your letter carefully for details on where your appointment will be and use the maps provided in this leaflet to guide you. Additional information on getting to Addenbrooke’s and different modes of transport can be found at Finding-us. Please note, if you arrive more than 30 minutes late for your appointment, you may not be seen.

Please contact us if you are travelling via hospital transport as this may determine the time of your appointment. Unfortunately, we are unable to see patients on beds or on stretchers in our outpatient department; please call us if this affects you.

Who will be present?

There will be a healthcare scientist present setting up the recording. Addenbrooke’s is a teaching hospital and you may be asked if you would consent to trainee staff performing the test under supervision or if you would mind other healthcare professionals/students observing the test. Refusing consent for this will not affect your test.

We have no provision for accompanying additional children to be looked after whilst you are having your EEG.

What happens during the equipment application?

A healthcare scientist will measure your head using a soft pencil, like a crayon, and a tape measure. They will then use a cotton bud and gritty paste, like an exfoliator, to clean small areas of the scalp, which is not painful, but does involve some rubbing. Small silver discs with wires on will then be attached to the scalp using a special sticky paste, a bit like Vaseline®, which will then be secured using small stickers. Everything will then be further secured using netting and bandages. There will also be some stickers applied to the shoulders and the upper parts of both arms in the same way to record heart rate and any movements. All the wires will be tied together and connected to a small box that records all the data, which will be carried around in a small bag. It is also helpful to wear loose fitting clothing (ideally something with buttons up the front) to avoid anything being pulled over the head whilst changing at home.

You should expect to be in the department for between 1 to 1.5 hours.

What happens after the equipment is applied?

You will be given a diary sheet to fill in during the recording, which will be explained during your first appointment. You may wish to have another person present for the duration of the recording to help you with recognising and documenting your events. You will also be given our contact details in the event of any questions about the equipment whilst you are at home.

How will you remove the equipment?

The healthcare scientist will stop the recorder and download the data and the recorder will be removed. We have a special liquid or wipes to help remove the sticky tape and we will remove as much of the products as possible but some residue will be left until you wash your hair with shampoo. You may wish to bring a cap or hat to wear afterwards. The removal of the wires should not be painful and will not damage your hair or scalp.

Are there any risks?

The recording itself is painless. Occasionally there can be slight redness or skin irritation where the electrodes have been attached, this usually gets better by itself.

Are there things to avoid during the recording?

The recording equipment must not get wet, so you cannot shower or have a swim. The electrodes on the scalp also mean you cannot brush your hair, or apply hair products, during the recording, and you cannot wash your hair. Please avoid chewing gum, as it affects the recording—but you can eat normal meals.

When do I get the results?

The results will not be available on the day of the recording. The healthcare scientist and doctor will review the data recorded and prepare a detailed report for the consultant neurologist who you normally see. The consultant will discuss the results with you at your next appointment.

Contacts / further information

If you need any further information or have any other queries please contact the neurophysiology administrator by phone on 01223 217136 Monday to Friday 08:30-17:00 or by Email.

If your appointment is in Clinic 33 of the Addenbrooke’s Treatment Centre

We are on level 3 in the Addenbrooke’s Treatment Centre (ATC). We are at the end of the corridor, just before the double doors to Papworth Hospital. You will find us next to the Endoscopy department.

If your appointment is in Neurophysiology in the Main Outpatients building

We are on level 3 in the Outpatients building area. You will find us in-between ward A3 and the Ultrasound department.

CUH Directions App

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My Chart

We would encourage you to sign up for MyChart. This is the electronic patient portal at Cambridge University Hospitals that enables patients to securely access parts of their health record held within the hospital’s electronic patient record system (Epic). It is available via your home computer or mobile device

More information is available on our website: My Chart