Please read this information carefully before coming in for your actigraphy leading into an overnight polysomnography.

What is an actigraphy?

Actigraphy is a non-invasive way to find out your sleep patterns by monitoring your rest and activity cycles over 1 or 2 weeks.

Why have an actigraphy?

If you are having problems with your sleep such as irregular sleep and wake times, or excessive sleepiness, you may be referred for an actigraphy test.

What happens during an actigraphy?

Actigraphy monitors movement over days or weeks in real life situations. It involves wearing a device like a watch which has an accelerometer that detects movements.

You will wear the watch on your wrist at all times for around 2 weeks and complete a diary sheet of your daily activities and sleep times. You must only remove the watch when you shower, bathe, or wash and then log this on the diary sheet. It is important that you remember to re-attach the watch after this.

You will press a button on the watch when you go to bed and when you wake up. This will be fully explained to you by the clinical neurophysiologist at your initial appointment. During this appointment, you will be given some diary sheets to write down your daily activities whilst wearing the watch.

After you have completed your period of actigraphy you must return the watch in person at the time specified in your letter. These watches are in high demand for use by other patients and failure to return at the specified time may result in the cancellation of other patient’s appointments.

Preparing for the test

• You can eat and drink as normal before the test.
• Please follow the guidance provided by your consultant neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You will be asked if you understand this information and whether you consent to the test before we start. You are welcome to ask the neurophysiologist doing the test to give you any further information or to explain more about the procedures.
• Your appointment should take approximately 10-15 minutes.

What is a polysomnography?

Polysomnography (also known as sleep studies) is a test used to diagnose sleep disorders. Electrodes and sensors are placed on the body and head to record different information that allow your sleep to be studied in detail for 1 or 2 nights. A video recording is taken during the study to help diagnose your sleep problem.

Why do a polysomnography?

The main reason is to try to classify (work out exactly) the problem you are having with your sleep so that the referring doctors can treat it more effectively.

What happens during the test?

Small discs (electrodes) are applied to your scalp, around your eyes, and under your chin. These will be attached with special glue, so they do not fall off in your sleep.

2 belts will be placed around your chest and abdomen (tummy) that measure your breathing, with additional boxes attached where the wires are connected. A nasal cannula will rest in your nose to also measure breathing.

2 sticky pads will be placed: 1 on your shoulder and 1 on your hip to detect your heart rate. A pulse oximeter will be placed on your finger to detect blood oxygen saturation. A movement sensor is placed on your arm and 1 on each of your legs to detect any movements in your sleep.

The equipment will stay in place until the end of the test, and it is removed by a neurophysiologist.

The night-time recording is started as close to your normal sleep time as possible. Wake time is usually before breakfast at around 08:30.

Are there any side-effects?

You will not feel anything during or after the recording. The machine records the normal natural activity seen during your sleep. After the equipment is removed, great care will be taken to remove as much of the glue as possible from your hair. Applying a hair conditioner and combing through your hair before having a shower or bath will help soften any glue left.

Preparing for the test

• Please follow the guidance provided by your Consultant Neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You must arrive with clean, dry hair with no grease, gel, wax, or other hair products.
• You will be set up in the clothes you sleep in, and won’t be able to change during the test. Please make sure you bring suitable nightwear such as shorts, pyjamas, t-shirt, or tracksuit bottoms. Nighties are not suitable.
• You will not be able to shower or bath during the monitoring period while the equipment is attached. This will be 1 or two nights and the equipment will stay in place for the whole time (including during the day). 

How long until I get my results?

The results will be sent to your GP/consultant. You will not receive any results during the test. Your consultant may send you a letter with the results or see you again for a follow-up appointment. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on 0117 414 1048 or 0117 414 1052 and a member of staff will be happy to help.

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003744

Please read this information carefully before coming in for your Nerve Conduction Study (NCS) and/or Electromyography (EMG).

What is an NCS?

NCS stands for nerve conduction study. It is a test that assesses the function of the sensory and motor nerve pathways, allowing us to see how the nerves are working. It is a non-invasive procedure, that records the electrical activity from the nerves in response to a series of small electrical impulses.

Why do an NCS?

If you are experiencing numbness, weakness, or other changes in sensation to your hands or feet you may be referred for a NCS to see if there is evidence of a trapped nerve.

What happens during an NCS?

At the start of the test, contact sites on your hands and feet will be wiped with alcohol gel to ensure a good contact with the recording discs.

The NCS is split into 2 tests.

First the sensory nerve pathways will be tested. Some stimulating rings will be applied to the fingers, or a recording bar will be used on your feet. Sticky pads to record the responses will also be applied to your skin.

Once everything is attached you will feel small electrical impulses from the rings on your fingers. The series of impulses will continue for several seconds, and the responses will be recorded on the machine. The rings will then be removed.

During the second part of the test the motor pathways will be tested. The sticky recording pads will be moved to different areas of the skin. A stimulating bar will then be applied, and you will feel the small electrical impulses once again and this time cause some twitching of your fingers and arms (if recording from your upper limbs), and legs and toes (if recording from your lower limbs).

The series of impulses will continue for several seconds, and the responses will be recorded on the machine. Once the test is over all the sticky pads will be removed and your skin wiped and cleaned.

What is an EMG?

EMG stands for electromyography. It is a test that assesses the function of individual muscles, allowing us to see how they, and the motor nerve pathways which control them, are working.

Why do an EMG?

If you are experiencing numbness, tingling, cramping, or unexplained muscle weakness you may be referred for an EMG to see if there is evidence of a muscle disorder or nerve damage affecting the muscles.

What happens during an EMG?

An EMG will be done after the nerve conduction study. A fine needle is inserted into the muscle being examined and then the response will record while the muscle is resting, during slight activity and when fully active. To do this, you will be asked to slightly flex the muscle which will produce crackling sounds on our machine, the clinician will then ask you to fully flex the muscle to which will cause louder crackling sounds. 

This may be repeated on several different muscles depending on the reason you are having the test.

The test can vary from 30 minutes to an hour, although occasionally it may take longer. Because of this we cannot guarantee that you will be seen exactly at the time of your given appointment. We do try to keep to the appointment system, so please attend in good time.

Preparing for the test 

• Wear loose fitting clothing with easy access to your upper arms and legs when stimulating the nerves.
• Do not apply moisturising products to your hands and feet before the test as these can affect our ability to record responses.
• Continue taking all regular medication and eat as normal before the test.
• Please inform the department before attending if you are have from an infectious condition, a bleeding disorder, take warfarin (or other anti-coagulant medications), or have a cardiac pacemaker fitted.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment you are welcome to ask the neurophysiologist doing the test to give you further information or to explain more about the procedures.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the NCS and EMG need to be fully analysed. 

A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003743

This page has information for patients who have had a blood transfusion. 

Most blood transfusions take place without problems but having a blood transfusion carries with it a very small risk of developing 
side effects. These may develop within several hours, or in some cases may happen days or weeks later.

These side effects are often mild, but it is still important to report any unusual or unexpected symptoms to a doctor or nurse (or midwife if your transfusion was related to pregnancy/childbirth).

Please contact the hospital for advice if you experience any of the following after having a blood transfusion:

• A high temperature - feeling feverish, hot, and clammy.
• Shivering or ‘cold chills’.
• Breathing problems.
• Extreme tiredness.
• Passing blood in your urine.
• Passing much less, or very dark, urine.
• Itchy skin rash.
• Pain in the lower back (loin pain).
• Unexpected or unexplained bruising.
• Jaundice (yellow colour of the white of your eyes or your skin).

When contacting the hospital for advice, please inform the hospital staff that you have recently had a blood transfusion.

On discharge the staff will explain to you how to obtain assistance in the event of a problem (both 'in hours' and 'out of hours'), and will give you a written copy of this information in a leaflet and:

• The ward/departments daytime, and night time/weekend contact phone numbers.
• The date and time of last transfusion.

If you are unable to make contact with the hospital where you had your transfusion, then please contact your GP as soon as possible.

In the rare event of an emergency (life threatening problems, for example difficulty with breathing), call 999 for an ambulance and bring your leaflet into hospital with you.

If you would like further information or advice about this, or other aspects of blood transfusion, please discuss this with your hospital doctor, nurse or midwife.

Giving blood after you’ve had a blood transfusion

If you’ve received a transfusion you’re no longer able to donate blood. This is one of the many safety measures in place to protect people who receive a transfusion.

References 

Acknowledgements: The Leeds Teaching Hospitals NHS Trust, Taunton & Somerset Hospital NHS Trust)

Information contained in this leaflet has been produced in collaboration with the NHSBT Better Blood Transfusion Team.

© North Bristol NHS Trust. This edition published January 2024. Review due January 2027. NBT002585

Please read this information carefully before coming in for your Natural Sleep Electroencephalography (nsEEG)

What is a natural sleep EEG?

A nsEEG involves recording the electrical signals from the brain, whilst you are awake and asleep. An EEG looks at how the brain is functioning rather than taking images as you would see in a scan. It is a non-invasive, painless procedure and you won’t need to shave or cut your hair.

Why do a nsEEG?

If you have been experiencing possible fits, seizures, faints, or “funny turns” you may be referred for a nsEEG. The nsEEG will assess your ongoing brain activity whilst awake and during sleep.

What happens during a nsEEG?

A nsEEG will take approximately around 90 minutes in total. Your head will be measured, then rubbed gently before 28 small metal electrodes attached to wires are applied using a soluble sticky paste. 2 electrodes will also be applied to your arms or shoulders to measure your heart rate during the EEG. You will be asked to relax on a bed with your eyes closed, the lights will be turned off and you will be allowed to drift off to sleep.

Natural sleep EEG

For this test you do not need to sleep deprive yourself, but we ask you not to nap or have any caffeinated drinks before your visit. Once the recording has finished all electrodes will be removed and your head wiped with warm water. You may still need to wash your hair when you get home.

Preparing for the test

• You must arrive with clean, dry hair free from grease, gel, wax or other hair products. You may wish to bring a comb or brush to tidy your hair after the test.
• You should avoid coffee or other caffeinated drinks before the test as this can affect your ability to fall asleep.
• We advise you have something to eat before coming for the test, preferably within 1.5 hours as you are more likely to sleep if you are full.
• Continue taking all regular medication as normal before the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment, you are welcome to ask the neurophysiologist doing the test to give you further information or to explain more about the procedure.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the nsEEG needs to be fully analysed. A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003742

Please read this information carefully before coming in for your Motor Evoked Potential (MEP) test.

What is an MEP?

MEP stands for motor evoked potential. It is a non-invasive procedure. It is a recording of the electrical signals that assess the function of the motor pathways in the brain, through the spinal cord and into the limbs. It looks at how these pathways are functioning rather than taking images as you would see in a scan.

Why do an MEP?

If you have been experiencing problems with your coordination, weakness, or other changes in limb function you may be referred for a MEP.

What happens during an MEP?

Once you are settled comfortably on the couch, your skin will be wiped with alcohol gel and small sticky recording pads will be placed over muscles in the hands and feet to record the responses.

A plastic paddle will then be held over your head by the physiologist. You will hear a clicking noise when the magnetic pulse from the coil stimulates the brain and this will then cause a response to be recorded from the fingers or toes, causing them to twitch in time to the pulses.

A series of these pulses are given, and the responses collected and stored on the computer.

These pulses can feel briefly uncomfortable but there are no known side effects once stimulation has finished.

The test takes around 60 minutes.

Once the recording has finished all the sticky pads will be removed and the skin wiped clean.

Preparing for the test

• You must arrive with clean, dry hair free from grease, gel, wax or other hair products. You may wish to bring a comb or brush to tidy your hair after the test.
• Please wear clothes which allow easy access to you lower arms and legs.
• Continue to take all regular medication as normal before the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment, you are welcome to ask the neurophysiologist doing the test to give you further information or to explain more about the procedure.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the MEP needs to be fully analysed.

A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003741

Please read this information carefully before coming in for your Lateral Spread Response (LSR).

What is an LSR?

LSR stands for lateral spread response. It is a test that assesses the function of a branch of the facial nerve. It is a non-invasive procedure, that records the responses of the muscles around the eye and mouth to a series of small electrical impulses delivered to the face.

Why LSR?

If you are experiencing hemifacial spasm (involuntary muscle contractions around the eye and mouth on 1 side of the face), you may have been referred for microvascular decompressive (MVD) surgery. Before your MVD surgery, you will be referred for a pre-operative LSR. This is so that the neurophysiology team can see if the LSR can be recorded during your surgery.

What happens during an LSR?

The test will take around 30 minutes. The LSR involves stimulation of the facial nerve.

You will be asked to relax comfortably on a couch whilst a few adhesive pads will be placed on the muscles around your eye and mouth. 

A series of small electrical impulses will then be delivered to a branch of the facial nerve, close to the ear, with a stimulator. During this time, you may experience some subtle twitching of the muscles around your eye, mouth, or both. This will just last for a few seconds whilst a response is collected and recorded on the machine. 

This procedure will need to be repeated a few times and will then also be repeated on the other side of your face.

Preparing for the test

• Continue taking all regular medication and eat normally before to the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment, you are welcome to ask the neurophysiologist doing the test to give you any further information or explain more about the procedures.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the LSR needs to be fully analysed. A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due Deember 2027. NBT003740

Please read this information carefully before coming in for your Electroencephalography (EEG)

What is an EEG?

EEG stands for electroencephalogram. It is a recording of the electrical signals from the brain, looking at how it is functioning rather than taking images as you would see in a scan. An EEG is a non-invasive, painless procedure and you won’t need to shave or cut your hair. 

Why have an EEG?

You may be referred for an EEG, if you have been experiencing possible fits, seizures, faints, or “funny turns”. The EEG will assess your ongoing electrical brain activity.

What happens during an EEG?

A routine EEG takes around 60 minutes. 20-30 minutes of this time involves measuring your head, and attaching small electrodes with a sticky paste. The rest of the time is to take the recording.

Your head will be measured, then rubbed gently before 28 small metal electrodes attached to wires are applied using a soluble sticky paste. 2 electrodes will be applied to your arms or shoulders to measure your heart rate during the EEG. You will relax on a bed with your eyes closed for most of the recording. Every so often the physiologist will ask you to open your eyes. After several minutes of recording, you may be asked to do some activation techniques including hyperventilation and photic stimulation. 

Hyperventilation

You will be asked to take deep breaths for 3 minutes with your eyes closed. You may feel lightheaded or have tingling in your fingers or lips during this, but these feelings will usually pass quickly once the task has finished. 

Photic Stimulation

You will be asked to look at a series of bright flashing lights with your eyes open and closed for 10 seconds at a time. During this part of the test there is a very small chance, if you are sensitive to flashing lights, that it may provoke a seizure. The physiologist will be watching the EEG at all times and if you appear sensitive they will stop the light immediately. 

Preparing for the test

• You must arrive with clean, dry hair free from grease, gel, wax or other hair products. You may wish to bring a comb or brush to tidy your hair after the test.
• We advise you have something to eat before coming for the test, preferably within 1.5 hours, as you are more likely to be comfortable during the test.
• Continue taking all regular medication as normal prior to the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment, you are welcome to ask the neurophysiologist doing the test to give you any further information or explain more about the procedures.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the EEG needs to be fully analysed.

A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003739

Please read this information carefully before coming in for your Brainstem Auditory Evoked Potentials (BAEP).

What is a BAEP?

BAEP stands for brainstem auditory evoked potential. It is a non-invasive, painless test that assesses the function of the nerves from the ears, and the pathways that travel along the brainstem (a part of the nervous system at the base of the brain). The test assesses the function rather than taking images as you would see in a scan.

Why do a BAEP? 

If you are experiencing changes to your hearing in both or 1 ear, a BAEP may be requested to determine whether there is a problem with how the auditory nerve pathway is functioning.

What happens during a BAEP?

A BAEP takes around 30-45 minutes. Your head will be measured, and a few small metal discs will be attached to your head. neck, and behind your ears with a sticky paste and possible some glue.

Once you are comfortable on a couch, a set of headphones will be placed on your head. From the headphones, you will hear clicking sounds of moderate intensity that will be applied to each ear for a short time. At this time, you will be asked to relax and lie with your eyes closed.

The series of clicks will continue for several minutes until all responses needed have been recorded.

Once the recording has finished all the metal discs will be removed and your head wiped with warm water, however, you may still need to wash your hair when you get home.

Preparing for the test

• You must arrive with clean, dry hair free from grease, gel, wax, or other hair products.
• Continue taking all regular medication and eat normally before to the test.
• If you have any obvious hearing problems or wear hearing aids, tell the physiologist before starting the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment, you are welcome to ask the neurophysiologist doing the test to give you further information or explain more about the procedures.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the BAEP needs to be fully analysed.

A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003738

R454 Mavacamten for treating symptomatic obstructive hypertrophic cardiomyopathy

Please read this information carefully before coming in for your Brainstem Auditory Evoked Potentials (BAEP) and Lateral Spread Response (LSR).

What is a BAEP?

BAEP stands for brainstem auditory evoked potential. It is a non-invasive, painless test that assesses the function of the nerves from the ears, and the pathways that travel along the brainstem (a part of the nervous system at the base of the brain). The test assesses the function rather than taking images as you would see in a scan.

Why do a BAEP? 

If you are experiencing changes to your hearing in both or 1 ear, a BAEP may be requested to determine whether there is a problem with how the auditory nerve pathway is functioning.

What happens during a BAEP?

A BAEP takes around 30-45 minutes. Your head will be measured, and a few small metal discs will be attached to your head. neck, and behind your ears with a sticky paste and possible some glue. 

Once you are comfortable on a couch, a set of headphones will be placed on your head. From the headphones, you will hear clicking sounds of moderate intensity that will be applied to each ear for a short time. At this time, you will be asked to relax and lie with your eyes closed.

The series of clicks will continue for several minutes until all responses needed have been recorded.

Once the recording has finished all the metal discs will be removed and your head wiped with warm water, however, you may still fneed to wash your hair when you get home.

What is an LSR?

LSR stands for lateral spread response. It is a test that assesses the function of a branch of the facial nerve. It is a non-invasive procedure, that records the responses of the muscles around the eye and mouth to a series of small electrical impulses delivered to the face. 

Why LSR?

If you are experiencing hemifacial spasm (involuntary muscle contractions around the eye and mouth on one side of the face), you may have been referred for microvascular decompressive (MVD) surgery.

Before your MVD surgery, you will be referred for a pre-operative LSR. This is so the neurophysiology team can see if the LSR can be recorded during your surgery.

What happens during an LSR?

The test will take around 30 minutes. The LSR involves stimulation of the facial nerve.

You will be asked to relax comfortably on a couch whilst a few adhesive pads are placed on the muscles around your eye and mouth.

A series of small electrical impulses will then be delivered to a branch of the facial nerve, close to the ear, with a stimulator. During this time, you may experience some subtle twitching of the muscles around your eye, mouth, or both. This will just last for a few seconds whilst a response is collected and recorded on the machine.

This procedure will need to be repeated a few times and will then also be repeated on the other side of your face.

Preparing for the test

• You must arrive with clean, dry hair free from grease, gel, wax, or other hair products.
• Continue taking all regular medication and eat normally before the test.
• If you have any obvious hearing problems or wear hearing aids, tell the physiologist before starting the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment, you are welcome to ask the neurophysiologist doing the test to give you any further information or explain more about the procedures.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the BAEP and LSR needs to be fully analysed.

A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003737