The Neurophysiology Department provides a Neuro Diagnostic service for Adults and children for the region.
Investigations include:
The electroencephalogram or EEG is the recording of brain activity by applying small discs (electrodes) to the head. The EEG records small changes in electrical potentials generated by the brain, and is used for the diagnosis of neurological conditions including Epilepsy.
A video recording will be made during the EEG recording to help with interpretation of the results.
Before the EEG we will ask you if you have read and understood the following information and whether you consent to the recording with video and the relevant activation techniques.
Allow 1 hour for the EEG.
Arrive with clean and dry hair. Have something to eat 1-2 hours before your appointment. Take your medications as usual. You may wish to bring a hat or comb with you to tidy your hair after the EEG.
The head is measured then rubbed with a cotton bud and electrode gel and 23 small discs/wires are applied to the scalp with a sticky paste. Additional wires may be placed on you to record your heartbeat (ECG) and muscle movements. You will be asked further information about your symptoms. During the recording period you will be asked to relax (either seated or lying down) and you will be asked to open and close your eyes. You will not feel anything from the wires during the recording.
You may also be asked to perform “activation techniques”
– Hyperventilation/Deep breathing
This involves you taking deep breaths in and forcing them out, as if blowing a candle out, you will be asked to continue with repeated deep breaths for 3-5 minutes. The deep breathing causes changes in the blood flow which may change your brain waves and give extra information to help your diagnosis.
It may cause you to feel dizzy/light-headed, or get a feeling of pins and needles/ tingling of the lips or fingers, these are normal side effects and will wear off after a few minutes. We will ask you about your general health beforehand in particular any heart problems or asthma.
There is a risk that Hyperventilation may trigger your symptoms, if you have been referred because of seizures, there is a risk of less than 3 in 100 that hyperventilation may induce a clinical event/seizure.
– Photic Stimulation
A bright light will be placed close in front of you and you will be asked to watch it flash on and off at different speeds, you will be asked to eyes open and close your eyes for a few seconds at a time.
It may cause you to feel dizzy/light-headed, your eyes may water or you may experience slight headache
There is a risk that photic stimulation may trigger your symptoms, if you have been referred because of seizures, there is a risk of less than 1 in 1000 that photic stimulation may cause a seizure.
– Sleep
A recording during sleep can sometimes be helpful so if you are drowsy during the test you may be allowed to drift off to sleep for a few minutes.
The electrodes are removed using warm water on cotton wool. Your hair will feel sticky and damp after until you are able to fully wash your hair. You will be able to return to your usual daily activities after the recording.
The EEG has to be analysed and a report will be sent to the referring doctor in 2–3 weeks.
An EEG will help your doctor to diagnose your symptoms and they will then be able to advise you with appropriate treatment if required.
There is a small chance that you may experience some reddening of the skin or soreness where the electrodes are applied, if you have sensitive skin.
There is a risk that the activation techniques/sleep deprivation may trigger your typical symptoms or a seizure. If this were to happen you would be looked after until you are well enough to go home.
If you choose not to have an EEG, this may delay your doctor finding out what is causing your symptoms and delay your treatment.
There is usually no alternative to this test that will give your doctor the information they need.
The electroencephalogram or EEG is the recording of brain activity by applying electrodes (small discs) to the scalp. The EEG records small changes in electrical potentials generated by brain, and is used for the diagnosis of neurological conditions including Epilepsy.
An Ambulatory EEG is a recording of the brain activity over a longer time period, usually 24 hours. The EEG is stored to a small recorder which you wear and this enables you to go about your usual activities, in your usual environment.
You will need to attend on two consecutive days, on the first day the electrodes will be applied to the scalp using specialised glue and attached to the recorder which will be placed in a small bag, that you will wear either on a belt or across your body on a shoulder strap. You will then be able to go home with the equipment on and continue with your usual activities, you will be given a diary sheet to complete. The following day you will need to return for removal of the electrodes and recorder.
Before the EEG we will ask you if you have read and understood the following information and whether you consent to the recording with video and the relevant activation techniques.
You will have two appointments on consecutive days, allow 40-60 minutes for each appointment.
Your first appointment
The head is measured then rubbed with a cotton bud and electrode gel and 23 small discs/wires are applied to the scalp with a sticky paste and specialised glue. Additional wires may be placed on you to record your heartbeat (ECG) and muscle movements.
You will be asked further information about your symptoms. The wires are connected to a small recording machine, which is then placed into a small bag. The bag is worn on a belt or across the body on a shoulder strap. You will then be able to go home.
As part of the test you will need to keep a diary, and press a button on the recording box when you have any symptoms/events.
You will not be able to have a bath or shower whilst the wearing the Ambulatory equipment but you are able to have a sponge wash. We ask that you also avoid chewing gum or too much vigorous activity during the recording as this can affect the quality of recording.
Your second appointment
The discs will be taken off with a chemical remover. You will need to remove loose bits of glue with a comb and then clean and condition the remainder out of your hair after your appointment.
When you come back for your second appointment the information will be downloaded from the recording box.
The head is rubbed firmly with gel before each electrode is applied with the paste and glue to enable a good quality recording, this can feel a little uncomfortable. The Ambulatory recorder must be worn on a belt or across the body on a shoulder strap throughout and it may become a little warm as it runs on batteries.
The electrodes are removed using a chemical remover, your hair will feel damp with loose bits of glue in until you are able to fully wash and condition your hair. You may like to bring hat with you for after the test. You will be able to return to your usual daily activities after the Ambulatory EEG.
There is 24 hours of EEG data which needs to be analysed. A report will be sent to the referring doctor in 2–3 weeks.
The benefit of an ambulatory EEG is that it can record your symptoms over a longer period than a routine EEG test and help your doctor to diagnose your symptoms and they will then be able to advise any appropriate treatment if required.
There is a small chance that you may experience some reddening of the skin or soreness where the electrode and glue is applied if you have sensitive skin. Care should be taken while the wires are attached to the head to avoid them becoming tangled either around yourself or an object.
If you choose not to have an Ambulatory EEG, this may delay your doctor finding out what is causing your symptoms and delay your treatment.
There is usually no alternative to this test that will give your doctor the information they need.
The electroencephalogram or EEG is the recording of brain activity by applying small discs (electrodes) to the head. The EEG records, small changes in electrical potentials generated by brain, and is used for the diagnosis of neurological conditions including Epilepsy.
A Sleep EEG involves recording the EEG during sleep. In order to capture sleep during the recording, we ask you to undergo sleep deprivation, this is sleeping less than usual and is done the night before the recording see “preparing for the sleep EEG” below.
The tiredness may result in brain waves on the EEG which are not usually seen whilst awake. You may fall asleep during the EEG and this may reveal new information that would otherwise have been unseen. A video recording will be made during the EEG recording to help with interpretation of the results.
Before the Sleep EEG we will ask you if you have read and understood the following information and whether you consent to the recording with video and the relevant activation techniques.
Allow 2 hours for the Sleep EEG.
Arrive with clean and dry hair. Have something to eat 1-2 hours before your appointment. Take your medications as usual. You may wish to bring a hat or comb with you to tidy your hair after the EEG
It is not safe/advisable for the patient or anyone who has stayed awake overnight with them, to drive or operate machinery after sleep deprivation
For adults (and older children)
For small children and babies
The head is measured then rubbed with a cotton bud and electrode gel and 23 small discs/wires are applied to the scalp with a sticky paste. Additional wires may be placed on you to record your heartbeat (ECG) and muscle movements. You will be asked further information about your symptoms.
During the recording period you will be asked to open and close your eyes, you will be laid down on a couch, for comfort you may be asked to remove your shoes and you may be covered with a blanket, the lighting will be dimmed you will be asked to relax and try to settle to sleep. You will not feel anything from the wires during the recording.
You may also be asked to perform “activation techniques” at some point in the recording.
– Sleep Deprivation
Sleep deprivation involves sleeping less than usual. The tiredness may result in brain waves on the EEG which are not usually seen whilst awake. The risks associated with this are:
Tiredness and poor concentration, it is not safe/advisable to drive or to operate machinery.
Sleep deprivation may trigger your symptoms, if you have been referred because of seizures there is a slightly increased risk of you having a seizure when you are sleep deprived. There are no definite figures available because of different methods in use but the risk is small and is similar to the risks quoted below for hyperventilation and photic stimulation
– Hyperventilation/Deep breathing
This involves you taking deep breaths in and forcing them out, as if blowing a candle out, you will be asked to continue with repeated deep breaths for 3-5 minutes. The deep breathing causes changes in the blood flow which may change your brain waves and give extra information to help your diagnosis.
It may cause you to feel dizzy/light-headed, or get a feeling of pins and needles/ tingling of the lips or fingers, these are normal side effects and will wear off after a few minutes. We will ask you about your general health beforehand in particular any heart problems or asthma.
There is a risk that Hyperventilation may trigger your symptoms, if you have been referred because of seizures, there is a risk of less than 3 in 100 that hyperventilation may induce a clinical event/seizure.
– Photic Stimulation
A bright light will be placed close in front of you and you will be asked to watch it flash on and off at different speeds, you will be asked to eyes open and close your eyes for a few seconds at a time.
It may cause you to feel dizzy/light-headed, your eyes may water or you may experience slight headache
There is a risk that photic stimulation may trigger your symptoms, if you have been referred because of seizures, there is a risk of less than 1 in 1000 that photic stimulation may cause a seizure.
The electrodes are removed using warm water on cotton wool. Your hair will feel sticky and damp after until you are able to fully wash your hair.
The Sleep EEG has to be analysed and a report will be sent to the referring doctor in 2–3 weeks.
A Sleep EEG will help your doctor to diagnose your symptoms and they will then be able to advise you with appropriate treatment if required.
There is a small chance that you may experience some reddening of the skin or soreness where the electrodes are applied, if you have sensitive skin.
It is advisable not to drive or to operate machinery due to tiredness and poor concentration after sleep deprivation. You will be able to return to your usual daily activities after the recording, although it is likely you will continue to feel tired and may need to catch up on your missed sleep
There is a risk that the activation techniques/sleep deprivation may trigger your typical symptoms or a seizure. If this were to happen you would be looked after until you are well enough to go home.
If you choose not to have a Sleep EEG, this may delay your doctor finding out what is causing your symptoms and delay your treatment.
There is usually no alternative to this test that will give your doctor the information they need.
What is a Nerve Conduction Study?
A nerve conduction study records how fast the nerves are sending messages. It involves wires/pads/rings (electrodes) being placed on your skin then an impulse is sent from one point on the skin to another.
After the nerve conduction study you may also need an electromyography (EMG) test, but this is not always necessary.
What is Electromyography (EMG)?
An EMG is a recording of activity from the muscles. It involves having a needle placed into the muscle to the activity.
We will ask you if you have read and understood the following information and whether you consent.
Allow 30-45 minutes depending on the problem being investigated.
You will be asked further information about your symptoms. We will also answer any questions you have.
The nerve conduction study will be performed by either a Consultant Neurophysiologist or a Clinical Physiologist. Your skin will be cleansed with an alcohol wipe; electrodes (pads, stickers and/or rings) will be placed on your skin. An impulse will be sent form one point on your skin to another; this will be felt as a tingling or pulsing/tapping sensation, and will sometimes cause the muscle (e.g. the thumb) to twitch, measurements will be taken and the response of your nerve to the impulse is recorded. This will be performed on different nerves to compare and see which, if any, are affected.
The EMG if needed will be performed after the nerve conduction study and is carried out by a Consultant Neurophysiologist. A very fine needle will be placed into the muscle. The needle will be in place for a few seconds and will be quickly withdrawn if you feel any discomfort. You will be asked to make the muscle move (for example by bending your arm). The needle will record how well the muscle is working on to the recording equipment and can sometimes be heard as loud crackling noises form a speaker on the recording equipment. Listening to the noises can help the Consultant Neurophysiologist analyse the recording.
After the tests you will be able to go back to your normal activities.
You won’t get the results straight after the test as they need to be analysed by the consultant. A report will be sent to the referring doctor in about 2-3 weeks.
Will I feel anything during the tests?
The NCS feel like tingling/tapping sensation on the skin, these are a bit uncomfortable but most people will be able to tolerate it okay. Many people who have used a TENS machine say the feeling is very similar.
The EMG needle tests are also a bit uncomfortable but usually quite tolerable as the needles used are very thin similar to acupuncture needles.
Inform the person performing the test if you find it too uncomfortable as the test can be stopped if needed.
The benefit of these tests is that they will show how your nerves and muscles are working which will help your doctor to diagnose if there are any problems so that they can advise on any appropriate treatment.
There is no serious risk or side effect to NCS/EMG. NCS can make the hands or feet tingle briefly, this resolves quickly. EMG needle test may cause you to feel slight tenderness where the needle was inserted after an EMG, but this only occurs very occasionally. In very exceptional cases there may be some slight bruising/bleeding, which resolves quickly.
Precautions If you have a pacemaker or are on any blood thinning medication (e.g. Warfarin) please contact the department on 01274 365107 so we can discuss this with you.
If you choose not to have NCS/EMG, this may delay your doctor finding out what is causing your symptoms and delay your treatment.
There is usually no alternative to this test that will give your doctor the information they need.
| Dr V Verma | Consultant Clinical Neurophysiologist |
| Karen Shepherd | Medical Secretary |
| Aishah Ahmed | Admin/Secretarial Support |
| Virginia Lockwood | Manager/Clinical Physiologist |
| Lisa Budgen | Clinical Physiologist |
| Angela Emery | Clinical Physiologist |
We are located in Area 1, Horton Wing, St Luke’s Hospital.
You will be able to ask any questions or tell us any concerns before the test is carried out but if you would like to contact us before your appointment please call:
Telephone 01274 365107
Internal enquiries Neurophysiology.Department@bthft.nhs.uk
Direct referrals brt-tr.bthtneurophysiology@nhs.net
Our opening times are Monday-Friday 8am-5pm (8am-4pm for phone lines, an answer phone is available outside these times).
Association of Clinical Neurophysiology https://www.ansuk.org/
The Registration Council for Clinical Physiologists https://www.rccp.co.uk/
The British Society for Clinical Neurophysiology http://www.bscn.org.uk/
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