Routine and Sleep Deprived EEG Investigations

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1 Feedback We appreciate and encourage feedback. If you need advice or are concerned about any aspect of care or treatment please speak to a member of staff or contact the Patient Advice and Liaison Service (PALS): Freephone: From a mobile or abroad: ext or pals@nuh.nhs.uk Letter: NUH NHS Trust, c/o PALS, Freepost NEA 14614, Nottingham NG7 1BR Routine and Sleep Deprived EEG Investigations Including risks and benefits of procedures performed within an EEG Information for patients Clinical Neurophysiology Department If you require a full list of references for this leaflet please patientinformation@nuh.nhs.uk or phone ext The Trust endeavours to ensure that the information given here is accurate and impartial. NUH02358N This document can be provided in different languages and formats. For more information please contact: Clinical Neurophysiology Department QMC Campus B Floor, West Block Tel: Andrea Bradbury, Clinical Neurophysiology Department June All rights reserved. Nottingham University Hospitals NHS Trust. Review June Ref: 1515/v4/0616/AS. Public information

2 This leaflet is aimed at all patients aged 17 years or over and their families, referred for routine or sleep deprived EEG investigations. This leaflet aims to provide relevant, up to date information explaining what an EEG is, and what happens during the test. General information about all EEGs What is an EEG? An EEG is a simple, routine test that records the electrical signals generated by the brain (brain waves). EEGs are carried out on all types of people from babies to older people. How will the EEG help my diagnosis? EEG is used to help diagnose a variety of illnesses. How it will assist will depend on the clinical problem you are experiencing, for example seizures or blackouts. The EEG may help us find the cause of your problem and therefore help your consultant to decide what treatment would work best for you. How does it work? Everyone produces brain waves all of the time and an EEG records these waves. If a person has a clinical condition that affects the pattern of these waves, an EEG may pick this up. Is the EEG safe? There is a small risk the EEG may bring on your typical attack (this is not our aim). This is usually the result of the breathing exercises we ask you to do, or through watching the flashing light. See risks and benefits of procedures carried out during an EEG section for more information. Who will see the video recording? The video recording will usually only be seen by the medical staff who have a direct responsibility for your care. Occasionally a video recording may be useful for educational purposes. In this case you will be asked if you would mind the video being shown to medical staff and/or students for educational purposes. If you agree, your written consent will be taken. You are, however, free to refuse this and in this case your video recording will only ever be seen by those directly responsible for your care. Students What types of student might want to be present during an EEG recording? Student nurses and doctors from the wards come to observe the EEG from time to time and occasionally students on work experience from school. Clinical physiologists that are training to qualify can assist with or perform parts of the EEG recording. If a student clinical physiologist assists with or performs part of the EEG, will it be done correctly? Yes. Where a student assists with or performs part of an EEG, it is always under the supervision of a senior clinical physiologist. Would students talk about my EEG recording and me to other people? No. All students adhere to the same strict patient confidentiality guidelines as qualified members of staff. Do I have a choice as to whether a student is present during my EEG? Yes. If a student wishes to be present during your EEG recording, whether to assist or just observe, we will ask your permission beforehand. You are under no pressure to agree and are free to refuse without this affecting your care in any way. 2 11

3 Are there any risks? Yes. Since you will be much more tired than usual, you should not drive and will need to make appropriate arrangements for travelling to and from the hospital. Although you may sleep during the EEG this will usually only be for less than an hour and you are still likely to be tired afterwards. It may also be a good idea to bring a friend or relative with you for the same reasons. There is a slightly increased risk of seizures occurring when you are sleep deprived. You may also be more sensitive to the flashing light when you are sleep deprived, which again increases the risk of you having a seizure. Are there any alternatives to sleep deprivation? Yes. Sleep deprivation is a natural method of inducing tiredness and often sleep. Certain drugs can be used to achieve this effect if necessary although these must be chosen carefully to ensure the drugs themselves do not affect your brain waves. In this department drugs are only used occasionally as an alternative to sleep deprivation. In these cases the consultant would always discuss this with the patient and/or patient s parents. Additional Information Video recording Why is video recording useful during an EEG? A video recording of what you do during the EEG can sometimes be very helpful in interpreting the information we record. If you have an episode typical of your symptoms during the EEG for example a seizure or blank spell it can also provide a very useful and permanent record of what happens to you or what your body does during these episodes. Can I refuse to be videoed? Yes. Before any video recording is made we will ask your permission and will ask you to sign a consent form. You will be under no pressure to agree to a video recording and your EEG can proceed without it. 10 Where is it done? The test is done in a recording room in the Clinical Neurophysiology Department on B Floor, West Block, in the Queen s Medical Centre Campus, Nottingham. The test will be performed by a clinical physiologist and there is room for someone to come in with you, should you wish. Is there anything I need to do before having the test? Read the risks and benefits of procedures performed in the EEG, found at the back of this booklet: it contains important information. Have clean, dry hair without any hair products in it. Have something to eat (e.g. a normal breakfast or lunch) Carry on taking any medicine as normal unless your doctor or consultant has told you not to. Bring any medicines (or a recent prescription) and glasses if you wear them. How long does it take? We usually allow minutes for this test. Please arrive promptly for your appointment. What happens before the test? Your head will be measured with a tape measure and little marks made on your scalp with a soft skin-marking crayon. These marks tell us where to stick the electrodes. Your scalp will then be rubbed with some mildly abrasive paste. This makes it easier for us to stick the electrodes to your head using water-based paste. This process takes minutes. 3

4 If at any time during the preparation you would like to ask us questions, feel free to do so. What happens during the test? Whilst we are recording your brainwaves we want you to be as comfortable as possible. Most people find they are most relaxed lying down. During your test the clinical physiologist will ask you to do various actions such as opening and closing your eyes, taking deep breaths and watching a flashing light. The recording itself takes minutes. Please note, we routinely video this test in case patients have any symptoms we need to re-examine. We will ask your permission to do this. What happens after the test? Once completed, we remove the electrodes. We will clean away most of the paste that is left in your hair with warm water but you may find a small amount remains, leaving your hair sticky. This is easily washed out at home with shampoo. Will I feel anything during or after the test? No, the test is completely painless and has no side effects. Are there any needles? No needles are used. You will not feel anything from the electrodes. Can you read my mind? No, we can only read signals not thoughts. When do I get the results? You will not get any results on the day of your test because it takes time to look at and analyse. We will send a report to your consultant, who will then ring or write to you and / or your GP.This takes at least four weeks. 4 Are there any risks? Most patients will only feel slightly dizzy after doing the deep breathing. However, there is a small risk that doing the deep breathing could cause you to have a seizure. Are there any alternatives to the deep breathing? There are no alternatives to doing the deep breathing. Other procedures can help to change the brain waves recorded on the EEG (showing a flashing light and sleep) but they are not a substitute for deep breathing. Sleep deprivation What is sleep deprivation? Sleep deprivation is the term used when you have had less sleep than usual. You may be asked to stay awake all night before your EEG recording or just to shorten the time you spend asleep. Your EEG will then be recorded the day afterwards. Are all patients sleep deprived before an EEG? Not all patients need to be sleep deprived before their EEG recording. This is dependant upon your symptoms or if your consultant feels it would be helpful. You will be told if a sleep deprived EEG is required when you make your appointment. How will a sleep deprived EEG help? Sleep deprivation serves two purposes. The first is that the tiredness that results from sleep deprivation may result in brain waves being seen on the EEG that would not usually be apparent. Secondly, because you are tired, you may fall asleep during the EEG recording. This again can change the brain waves seen and can reveal important new information that may otherwise remain unseen. 9

5 Once the flashing light part of the test has finished you will be at no more risk than normal from having a seizure, as seizures triggered by flashing lights occur immediately, not several hours afterwards. Are there any alternatives to the flashing light? Ways of finding out if you are photosensitive will always carry a small risk. In rare cases your consultant may think it will be useful to record your brain activity while you play a computer game or watch television instead of using the flashing light. Deep breathing What does the deep breathing part of the test involve? You will be asked to breathe in and out through your mouth quite forcefully as if blowing out a candle. You may be asked to do this for up to four minutes. While you are taking the deep breaths the clinical physiologist will be recording your brain waves on the EEG. While you do the deep breathing you may start to feel dizzy and you could have pins and needles in your fingers, toes and face. This is a normal side effect to doing the deep breathing and goes away a few minutes after you have stopped. Are all patients asked to do the deep breathing? You will not be asked to do the deep breathing part of the test if you are 65 years of age or older, or if you have certain medical problems. The clinical physiologist will ask questions about your health (heart, blood pressure, asthma and so on) and make sure that it is safe for you to do the deep breathing. How will doing the deep breathing help? Doing the deep breathing causes slight changes in the blood flow to your brain, which is why you may feel dizzy. As a result, the brain waves recorded on the EEG may change. This new information may be useful in finding a diagnosis for your problem. Sleep Deprived EEGs How will I know I need a sleep deprived EEG? We will discuss this with you when you ring to make your appointment. How will a sleep deprived EEG help? This test will be carried out after you have deprived yourself of sleep the previous night. This can help enhance certain features in the recording or is suitable if you typically have your attacks / episodes during the night. It is quite common to have this done following a routine EEG but equally, this may be your first visit. Is there anything extra I need to do before the test? As well as the points mentioned on page 3, you need to additionally; Stay awake throughout the night before your test. If you would usually drive to your appointment, please make alternative arrangements. We do not advise anybody (patient or otherwise) to drive after they have been sleep deprived. Is the test any different from a routine EEG? Not really. It is the deprivation of sleep that may give us more information. The set-up and recording is essentially the same. Additionally it is hoped (but not essential) you will fall asleep. The recording itself can last a little longer: up 40 minutes. Why doesn t everyone have a sleep deprived EEG? Not everyone needs one! A routine EEG often gives enough information to help your consultant without the need for sleep deprivation. Please DO NOT deprive yourself of sleep if you have not been asked to by your consultant or the clinical neurophysiology department. 8 5

6 Risks and benefits of procedures performed within the EEG Introduction A basic EEG (electroencephalogram) can be recorded with you lying on the bed or sitting in a chair, occasionally opening and closing your eyes. This information in itself is very useful. However, in order to try to get as much information as possible in the short time available, we ask patients to undertake procedures during the EEG that may change the brain waves and reveal new information. There are usually three things we can ask a patient to do that may alter the brain waves flashing a light, doing some deep breathing and going to sleep. Which of these you are asked to do will depend upon factors such as your age, the reason you have been referred and your general health. Sometimes your consultant will ask you to be sleep deprived before having your EEG recorded. This leaflet describes the procedures mentioned above and tells you about the benefits and risks of each, so that you are able to make an informed decision about whether you wish to undertake these tasks during your EEG recording. It is possible that you may have a seizure during the session. If this happens you will usually be able to recover in the department, provided we have the room. However, if you remain disorientated for more than one or two hours you may be taken to the Emergency Department. Having a seizure (even one, regardless of circumstances) means that you must stop driving for a time. You have a responsibility to inform the DVLA. If you do not stop driving your consultant has a responsibility to the general public, which comes before confidentiality, and he or she would be obliged to contact the DVLA. More information can be found in the Epilepsy Action leaflet Epilepsy and Driving (2015). 6 When you attend the department for your EEG the clinical physiologist will be able to explain these points again. You will be asked whether you wish to undertake these procedures and, if you agree, your verbal consent will be noted. You will not be under any pressure to undertake these procedures and are free to withdraw your consent at any stage during the EEG recording. The flashing light What does the flashing light part of the EEG involve? A lamp will be placed in front of you and you will be asked to look at a point in the middle. The light will flash for a few seconds, sometimes slowly and other times quickly. The clinical physiologist will ask you to open and close your eyes. How will it help? Your brain responds to the flashing light and the responses are recorded in the EEG. This provides useful information for all patients as to whether both sides of the brain are producing the same activity. A small percentage of patients may have seizures or other events that are triggered by flashing lights, televisions or computer screens (photosensitivity). In these patients the brain waves recorded while the light is flashing can show a certain type of response (a photosensitive response ). This can lead to a definite diagnosis and therefore may help your consultant with your treatment. Are there any risks? When a patient has a photosensitive response the light is turned off very quickly and patients do not usually go on to have a seizure. However, there still remains a small risk that you could have a seizure triggered by the flashing light. 7