Neurophysiology

If you are unable to attend, please let us know as soon as possible.

What is an EEG ?

• EEG stands for ElectroEncephaloGram, which is the recording of the electrical activity of the brain.

How do I prepare for an EEG?

• Go to bed and get up at your usual time.
• Ensure to eat before an EEG and do not fast.
• Continue to take your medication as normal unless otherwise stated.
• Please ensure your hair is clean and dry. Do not use any hair products such as gel or hairspray and remove any hair extensions/weave/wig. You may wish to bring a comb to tidy your hair after the test
• Please do not bring children to the department. They will not be allowed into the testing rooms and cannot be left unsupervised in the waiting area.

Arriving to St James’s Hospital Clinical Neurophysiology Department
The car park can be very busy so ensure you give yourself enough time.

How is an EEG performed?

• An EEG takes approximately one hour to perform.
• The physiologist will take measurements of your head, then make marks with a pencil and gently rub the skin with a cotton bud before attaching electrodes (small metal discs) to your scalp using a sticky paste.
• After the leads are in place the recording itself takes approx. 20-30 minutes.
• During the recording you will be lying or sitting down and asked to relax and try to stay still. The more relaxed you are the better the recording.
• The physiologist will ask you to follow simple instructions, such as to:

- open and close your eyes.

- breathe deeply for 3 minutes with your eyes closed (hyperventilation)

- look at a flashing light with eyes opened and closed (photic stimulation)

• Very rarely, hyperventilation or flashing lights can cause a seizure. If this happens, the exercise will be stopped and the staff are trained to respond.
• An EEG does not hurt and there are no side effects.
• The test is filmed in the event that you have a seizure, as this will help with the diagnosis. This will be explained to you and we will ask for your consent.

What happens after the test?

• When the recording is over, the electrodes are removed.
• You can return to work or school after the EEG. Your hair will be quite sticky after the test due to the paste but this will wash out with shampoo.
• After the EEG is performed it needs to be interpreted by a Consultant Clinical Neurophysiologist. You will not get a result on the day of the EEG. The report will be sent to the doctor who referred you.

If you are unable to attend, please let us know as soon as possible.

What is an EEG?

• EEG stands for ElectroEncephaloGram, which is the recording of the electrical activity of the brain.

How do I prepare for a Sleep Deprived EEG?

• The night before you must stay awake from 2a.m.  Please do not use any stimulants such as coffee, cola, red bull or any other drinks with caffeine to help you stay awake.
• Ensure to eat before an EEG and do not fast.
• Continue to take your medication as normal unless otherwise stated.
• Please ensure your hair is clean and dry. Do not use any hair products such as gel or hairspray and remove any hair extensions/weave/wig. You may wish to bring a comb to tidy your hair after the test
• You should not drive or travel unaccompanied to and from the appointment. (see “What happens after the test”)
• Please do not bring children to the department.  They will not be allowed into the testing rooms and cannot be left unsupervised in the waiting area.

Arriving to St James’s Hospital Clinical Neurophysiology Department

The car park can be very busy so ensure you give yourself enough time.

How is a sleep deprived EEG performed?

• This is done in the same way as a normal EEG, but hopefully you will fall asleep during the test. 
• The physiologist will take measurements of your head, then make marks with a pencil and gently rub the skin with a cotton but before attaching 27 electrodes (small metal discs) using a sticky paste.
• After the leads are in place the recording itself takes approx. 60-90 minutes
• During the recording you will be lying or sitting down and asked to relax and try to stay still. The more relaxed you are the better the recording.
• The physiologist will ask you to follow simple instructions, such as to:

- open and close your eyes. The majority of the recording will be carried out with your eyes closed.

- breathe deeply for 3 minutes with your eyes closed (hyperventilation)

- look at a flashing light with eyes opened and closed (photic stimulation)

• Very rarely, hyperventilation, flashing lights or sleep deprivation can cause a seizure. If this happens, the exercise will be stopped and the staff are trained to respond.
• An EEG does not hurt and there are no side effects.
• The test is filmed in the event that you have a seizure, as this will help with the diagnosis. This will be explained to you and we will ask for your consent.

What happens after the test?

• When the recording is over, the electrodes are removed. Your hair will be quite sticky after the test due to the paste but this will wash out with shampoo.
• You should not drive or travel unaccompanied at this time, and it is mandatory to have somebody to accompany you.  You should be supervised for the following 24 hours, including during sleep, as there is a possible increased risk of a seizure when you are sleep deprived. If you fail to bring somebody to accompany you, your test will be cancelled.
• After the EEG is performed it needs to be interpreted by a Consultant Clinical Neurophysiologist. You will not get a result on the day of the EEG. The report will be sent to the doctor who referred you.

How is HVT performed?

First visit to hospital

• You will come to the Neurophysiology Department on the morning of your appointment for set up. This takes 60-90 minutes.
• The physiologist will take measurements of your head, then make marks with a pencil and gently rub the skin with a cotton bud before attaching 27 electrodes (small metal discs) using a special paste.
• The electrodes are attached to a small head box which you will carry around your waist or chest.
• You will also go home with a camera/patient event button and an event diary to fill out.

Event button and headbox you will carry.

At home

• Please ensure a relative/friend who is familiar with your events is available to stay with you during this 24-hour period.
• It is very important to fill out the event diary. Please document all events, as well as aspects of your daily routine (eating/drinking/going to bed/what time you got up etc). Typical events should be documented to include description/duration/were you aware or unaware.
• If an event occurs, please ensure to press patient event button and document the time you did so in the diary.
• It is important to have the camera as close to the patient as possible, in order to capture the event clearly.
• It is imperative to keep equipment safe at all times. Do not shower while equipment is in situ.

Second visit to hospital

• You will return the following day at an agreed time for disconnection. This will take 30-40 minutes.
• Your hair will be quite sticky after the test due to the paste but this will wash out with shampoo.
• After the HVT is performed it needs to be interpreted by a Consultant Clinical Neurophysiologist. The report will be sent to the doctor who referred you. This can take several weeks

A technician will ring you the week before the appointment date in order to confirm the testing details.

If you are unable to attend, please let us know as soon as possible.

What are Nerve NCS/EMG?

• Your nerves are like electrical cables carrying information to and from your brain. A nerve conduction study (NCS) is performed to test the nerves in the arms or legs if someone is experiencing tingling, numbness, pain or loss of power in a limb. Electromyography (EMG) is used to study muscle function.

How do I prepare for NCS/EMG?

• You can continue to take your medication as normal unless otherwise stated.
• Please let us know if you are taking any blood thinners.
• You should let the doctor know if you have a pacemaker.
• Please wear loose clothes that can be rolled up to above your knees and elbows. If the clothing is not appropriate for the test, we may ask you to wear a hospital gown. If we are testing the legs, you will be asked to take off shoes, socks or tights.
• Do not apply creams/ointments on the day as they can interfere with the test.
• Please do not bring children to the department.  They will not be allowed into the testing rooms and cannot be left unsupervised in the waiting area.

Arriving to St James’s Hospital Clinical Neurophysiology Department
The car park can be very busy so ensure you give yourself enough time.

How are NCS/EMG performed?

• Depending on your symptoms, you may need to have one or both of the tests on your arms/legs and sometimes face muscles
• A test can last between 30 and 90 minutes, depending on the reason for the test and number of nerves/muscles that needs to be tested
• If your hands/feet are not warm enough, we will ask you to sit with your hands/feet in warm water for a few minutes.
• A nerve conduction study is performed by passing small electrical currents through the skin at the site of the nerve, by placing electrodes on the skin. 
• The electrical pulses will cause a tingling sensation or a muscle twitch. This can be unpleasant, but should not cause too much discomfort
• If Electromyography (EMG) is needed, this is done by the doctor who will insert a small needle into some muscles to assess your own “electrical activity”. This will feel like a pinprick and may cause a small amount of bleeding. Electrical pulses are not passed into the muscle.  This part of the test can also be a little uncomfortable. There are no side effects of having nerve conduction studies. If a needle EMG is performed, there is a small chance of localised bruising.

What happens after the test?

• You can return to work or school after the test and go back to your usual activities.
• After the test is performed it needs to be interpreted by a Consultant Clinical Neurophysiologist. You will not get a result on the day of the NCS/EMG. The report will be sent to the doctor who referred you.

If you are unable to attend, please let us know as soon as possible.

What is a VEP/SSEP?

You may be required to have one or both of the tests below. Please see your appointment letter.

Visual evoked potentials (VEP) are the electrical responses recorded from the back of the head, over the brain areas involved with vision when this is stimulated. This test looks at the function of the optic nerve, located between the eye and the brain.

Somatosensory Evoked Potentials (SSEP) are the electrical responses in the brain and the spinal cord when a nerve in the arm/leg is stimulated with a small electrical pulse.

How do I prepare for a VEP/SSEP?

• Please ensure your hair is clean and dry. Do not use any hair products such as gel or hairspray and remove any hair extensions/weave/wig. You may wish to bring a comb to tidy your hair after the test
• For VEP- please bring your glasses or contact lenses with you
• For SSEP- please wear loose clothing that can roll up and do not use any body lotions on your skin on the day of your test. You should let the doctor know if you have a pacemaker.
• Please do not bring children to the department. They will not be allowed into the testing rooms and cannot be left unsupervised in the waiting area.

Arriving to St James’s Hospital Clinical Neurophysiology Department

The car park can be very busy so ensure you give yourself enough time.

How is a VEP/SSEP performed?

• The physiologist will take measurements of your head, then make marks with a pencil and gently rub the skin with a cotton bud before attaching a few electrodes (small metal discs) using a sticky paste.

Visual evoked potentials (VEP)

• During the recording you will be sitting down and asked to relax and to look at a checker board pattern on a screen or a flashing light.
• We will turn down the lights in the room and cover one eye at a time
• The test is completely painless and it takes 30-45 minutes.

Somatosensory Evoked Potentials (SSEP)

• You will have electrodes placed on your arms/legs, in addition to the electrodes placed on your head
• Following placement of electrodes, an electrical stimulus is applied to the arm or leg and the signal is recorded from the brain.
• The test only causes minimal discomfort and it takes 60-90 minutes.

There are no side effects from VEP/SSEP

What happens after the test?

• When the recording is over, the electrodes are removed. You can return to work or school after. Your hair will be quite sticky due to the paste but this will wash out with shampoo.

After the test is performed it needs to be interpreted by a Consultant Clinical Neurophysiologist. You will not get a result on the day of the VEP/SSEP. The report will be sent to the doctor who referred you

If you are unable to attend, please let us know as soon as possible at 410 3654 / 416 2847 or langansec@stjames.ie

What is Botulinum Toxin (botox) treatment?

• Botulinum toxin (botox) can be used to treat spasticity (involuntary tightness of muscles), dystonia (movement disorder in which muscles contract uncontrollably) and some cases of tremor.
• The toxin is injected into muscles and works by blocking the connection between nerves and muscles. As a result, the injected muscles become weaker.

How do I prepare for Botulinum Toxin (botox) treatment?

• You can continue to take your medication as normal unless otherwise stated.
• Please let us know if you are taking any blood thinners.
• Please wear loose clothes that can be rolled up to above your knees and elbows. If the clothing is not appropriate for the test, we may ask you to wear a hospital gown.
• Please do not bring children to the department.  They will not be allowed into the testing rooms and cannot be left unsupervised in the waiting area.

Arriving to St James’s Hospital Clinical Neurophysiology Department
The car park can be very busy so ensure you give yourself enough time

How is Botulinum Toxin (botox) treatment performed?

• We use an EMG (electromyography) machine to help us guide the injections. This registers the electrical activity of the muscle through the same needle used for injections, so we know that Botox is only injected into the muscles we want.
• Botulinum toxin injections produce no more discomfort than ordinary injections
• The appointment can last approximately 15 minutes, depending on the reason for the test and number of muscles that need to be injected

What are the side effects of Botulinum Toxin (botox) treatment?

• As with any injection you may experience bruising or pain at injection site.
• The main side effect however is weakness of the muscles injected and less often of those just next to them (including a drooping eyelid following injection around the eye area, swallowing difficulties following injection to the neck region). 
• However, we usually do not see any improvement in symptoms unless some weakness is produced.

What happens after the test?

• It may take up to 2 weeks for you to see any benefit.
• The effect lasts for 3 to 4 months following which the injections will usually need to be repeated.
• You can return to work or school after the test and go back to your usual activities after the botox treatment.
• If you are being treated for spasticity, you will need intensive physiotherapy after the injection. Your physio should send a report to Dr Langan 6 weeks after the injection.