Home video-telemetry (HVT) - adult

This leaflet is designed to give you some information about the investigation for which you have been referred. We hope it reassures you. We have a team experienced in these investigations; you will have the opportunity 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. The 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 a home video-telemetry (HVT)?

Home video-telemetry records EEG with video over a long period of time, usually between 24 and 72 hours and takes place at home whilst you carry on with your everyday tasks. The equipment includes a small video-camera to record any events that you may experience during the recording.

Why am I having HVT?

There are many reasons for having home video-telemetry. You may be having events that can be recorded on video and EEG to help the medical team looking after you find out what is causing them or work out how many are occurring. Sometimes the recording is useful to find out about brain activity during sleep.

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

• The week before the investigation you will have a telephone or virtual appointment with our team to discuss the test and to allow us to take more details about you. It will be helpful if you could tell us about any current events as well as have a list of any medication. 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.
• When attending the face-to-face appointment the following week it is important that your hair is clean using shampoo and conditioner, making sure to avoid all additional hair products.
• It is also helpful for you 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?

There are two neurophysiology 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.

We recommend you do not travel home via public transport. If this is unavoidable or you have any other queries, please contact us on 01223 217136 to discuss.

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. If you do not give consent for this it will not affect your test.

We have no provision for accompanying 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 discs 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.

What happens after the equipment is applied?

During your appointment we will show you how to set up the camera and use the equipment at home. We will also give you a leaflet with this information and a diary sheet to fill in during the recording. There is a button on the equipment to press if you have an event and a microphone records sound so you can explain what is going on. Everything will be explained in more detail when you attend your appointment and contact details will be made available for any questions you might have whilst at home. It would be helpful if someone can come to the appointment and stay with you for the duration of the recording.

How do I remove the equipment?

We will show you how to remove the wires at the end of the recording. We will arrange for a courier to come and collect the equipment at a time convenient for you.

Are there any risks?

The recording itself is painless. Occasionally there can be slight redness or skin irritation where the electrodes have been attached, but 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. You can eat normal meals, but please avoid chewing gum, as it affects the recording.

It is advisable not to go to work during the recording as we will be recording you on video and will not have consent to record people you work with. If you would like to discuss this with us, please call us on the number provided below.

We advise that you stay in one or two rooms of the house during the recording to ensure any events are not missed on the video. The camera has a night mode which will help to record events during sleep.

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 whom 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 (8:30am) to 17:00 (5pm) 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 between ward A3 and the Ultrasound department.

My Chart

We would encourage you to sign up for My Chart. 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.