Diagnostic Neurophysiology

An electroencephalogram (EEG) is a record of brain activity. Your child or youth must be sleep-deprived the night before the EEG. In addition, children/youth must: 

• Arrive awake to the test
• Fall asleep during the test
• Have clean, dry hair (no gel, hairspray, or oils)
• Take their medication as usual (unless they have been directed not to do so by a doctor) 

During the test

• A technologist will measure your child or youth's head and place approximately 25 electrodes on top of the scalp with a special paste. It is important that your child or youth can lie still while we set up the test
• If your child or youth is old enough, we will ask them to open their eyes, watch a special flashing light (photic stimulation) and do some deep breathing with a pinwheel (hyperventilation)
• It is normal for children or youth to get upset during parts of the test as they will be very tired. Some children are not able to understand everything that is happening, but the EEG is not painful and the technologist will work with you to find the best way to do the test
• After this, your child or youth will lie quietly with their eyes closed. This is when we are waiting for sleep
• Once the recording is done, we will remove the electrodes with warm water

Read our step-by-step guide on the EEG test (PDF).  

Ambulatory monitoring is a prolonged, continuous electroencephalogram (EEG) recording using a small portable computer that you take home. We can use this to record sleep during the night, capture "events" or seizures, or determine what kind of seizures a child is having and their frequency.  

How to prepare

• A responsible adult (parent, family member or caregiver) must be with your child at all times during the monitoring
• Your child must have clean, dry hair (no gel, hairspray or oil)
• Make sure your child or youth is wearing clothing with buttons or a zipper. They will not be able to remove clothing over their head while the equipment is in place
• Some children can feel self-conscious about wearing the equipment, so we suggest they bring a large hat or zip-up hoodie and their own backpack
• You will need to sign a release form stating that you accept responsibility for the equipment

During the test

• We apply electrodes as for a routine EEG test (please see the EEG tab above for further information). We apply the electrodes with a special hair glue and then cover them with a hat (similar to a bathing cap). Your child or youth must wear this hat at all times during the monitoring
• Once we have applied the electrodes to your child or youth's head, we attach them to a small, battery-operated computer. We put the computer into a backpack that your child or youth will wear or carry with them at all times during the monitoring. This backpack weighs about 2 pounds (just under 1 kg)
• Before you leave the department, the technologist will show you how the equipment works and what you will need to do. The technologist will also show you how to check the machine to make sure that everything is running properly
  • Attached to the computer is an alarm/event button. When your child or youth has an "event", press the button
  • This will be a guide for the doctor when they read the test. The beginning of an event gives us the best information, so press the button as soon as possible after the event starts
  • In the diary we give you, write down the time of the event and a description of what your child or youth was doing at that time
• During the test, your child or youth cannot shower or bathe. The equipment must not be exposed to water
• Please keep your child or youth home from school while they are being monitored, unless the "events" in question only happen at school or during school activities
• It is important that your child or youth does not participate in any "rough play" or sports while wearing the monitoring equipment

You will come back the following day to have the electrodes taken off. This usually takes about 30 minutes. 

Intensive monitoring is a continuous electroencephalogram (EEG) video recording that we do while your child or youth is admitted to the hospital. This can be to record sleep throughout the night, capture "events" or seizures, establish the type and frequency of seizures, or determine if they may be a candidate for epilepsy surgery. 

How to prepare

• Your child may need to be sleep-deprived for the Epilepsy Monitoring Unit admission.
• You and your child will spend the monitoring time in a private room in a hospital unit in the Teck Acute Care Centre.
• We need you to be with your child or youth at all times.
• It is up to you to arrange for other adults to share the observing. This is not something the nurses can do for you.
• Bring activities that your child or youth can do in bed. Children or youth can use electronic games (for example, Nintendo or PlayStation) as long as they are battery-operated. The room has a TV and a DVD player.
• Your child or youth cannot take a bath or shower during the monitoring time.
• Children should wear a button-up or zip-up top because they cannot remove clothing over their head during monitoring.
• All children must have clean, dry hair (no gel, hairspray or oil).

During the test

• We apply electrodes as for a routine EEG test (please see the EEG tab above for further information). We apply the electrodes with a special hair glue and then cover it with a hat (similar to a bathing cap). Your child must wear this hat at all times during the monitoring.
• Once we have applied the electrodes, we attach them to a small box. We put the box into a backpack that your child will wear/carry with them at all times during the recording.
• We will take you to the ward, where your room will have a camera, microphone, and special lighting for monitoring.
• The box in the backpack is attached to a long cable that plugs into a computer. The cable is long enough to allow your child or youth to walk to their private bathroom.
• The technologist will review what you need to know about the equipment and what you will need to do during the monitoring.
• After the monitoring is finished, we will remove the electrodes. If the electrodes have been on for more than one day, your child or youth might have some sore spots where the electrodes were sitting.
• Monitoring can last from 1 to 5 days.

A nerve conduction study (NC) records how fast messages travel along the nerves in the arms and legs. Electromyography (EMG) records the electrical response of specific muscles. We usually do both tests together, and complete the NC first.

How to prepare

• Most children tolerate the procedure well, but some patients benefit from sedation to help them lie still, particularly during the EMG
• Your child should wear loose-fitting clothing that can easily be pulled up over elbows and knees (a t-shirt and shorts/track pants work best)
• Bring a comfort item if you feel it will help (stuffed toy, soother, blanket, etc.)

During the test

• The test lasts approximately one hour
• We do the NC test first. We put electrode stickers on the wrist or ankle. Your child or youth will feel a tingling sensation or tapping which will make their fingers or toes jump. This can feel strange but doesn't usually hurt
• If your doctor has requested an EMG, we will do this next
• We will place the tip of a very small, thin needle into the muscle and the doctor will ask your child or youth to move in a certain way. There may be some minor discomfort from the needle poke, but this will only last for a few seconds

Read our step-by-step guide on the NC EMG tests (PDF). 

The technologist cannot give you the results of the test. We will analyze the information and send the report electronically to the referring doctor.

This test records the response of the brain’s visual centre to a checkerboard picture or flashing light. It checks the visual pathway and ensures that the brain is receiving information about what your child's eyes see. 

How to prepare

• It is important that your child or youth is awake and alert for this test. Please make sure they have a good sleep the night before and a nap before the test if this is part of their normal routine
• If your child or youth is also having an EEG test during this appointment, please do not follow the sleep deprivation instructions
• All children must have clean, dry hair (no gel, hairspray or oil)
• Children who wear glasses or contact lenses should wear these during the test

During the test

• The test will take 60-90 minutes
• There are two different types of VEPs: flash and pattern
• Flash VEP
  • We attach 26 electrodes to your child or youth's head. It is important that the child or youth can lie still for this part of the test
  • Your child or youth will need to watch a strobe light that flashes a white light about once every second
  • A computer registers the electrical signals from the brain during this time
  • In some instances, we will ask your child or youth to place a patch over one eye to record the brain's response from each eye separately
• Pattern VEP
  • We attach six electrodes to your child's head
  • Your child or youth will sit in a chair in front of a screen that has a black and white checkerboard pattern
  • We place a patch over one eye and record the brain's response from each eye separately

Once the VEP test is finished, we remove the electrodes with warm water. You can wash your child or youth's hair with shampoo at home if there is still some paste left.

This test records how long it takes for sound to travel from the ear to the brainstem. It does not test how well your child or youth hears. 

How to prepare

• Your child/youth must be sleep-deprived the night before the test
• We may sedate some children for this test as it is very important for them to lie still. Our sedation nursing team will contact you if your child will be receiving sedation
• All children must have clean, dry hair (no gel, hairspray or oil)

During the test

• The test will take 60-90 minutes
• We attach four electrodes to the top of your child's head (two on top of the head and one on each earlobe)
• We place small foam earpieces in each ear
• We test each ear separately. There will be a small clicking sound in the ear being tested, and a "whooshing" sound in the other ear

Once the BAER test is finished, we remove the electrodes with warm water. You can wash your child's hair with shampoo at home if there is still some paste left.

This test checks how well the spinal cord conducts a message from the arms and legs to the brain.  

How to prepare

• Your child/youth must be sleep-deprived the night before the test
• We may sedate some children for this test as it is very important for them to lie still. Our sedation nursing team will contact you if your child will be receiving sedation
• All children must have clean, dry hair (no gel, hairspray or oil)
• Your child should wear loose-fitting clothing that they can easily pull up over elbows and knees. A t-shirt and shorts/track pants work best

During the test

• The test takes 90 minutes to 2 hours
• The technologist applies electrodes to various points on your child’s body, including the top of your child’s head
• During the test, your child will feel a tingling sensation which will cause their thumbs and toes to twitch. This does not hurt but may feel uncomfortable

Once the SEP test is finished, we remove the head electrodes with warm water. You can wash your child's hair with shampoo at home if there is still some paste left. We remove the electrode stickers with an alcohol wipe. 

Intraoperative monitoring makes sure that the pathways to and from the brain are not compromised during surgical procedures. Examples of surgical procedures include correcting orthopedic scoliosis or removing neurosurgical tumours. 

We will give you more information at the time of booking or before the operation, when you meet with the surgeon.

Sleep deprivation is needed for: 

• All routine electroencephalogram (EEGs)
• Any test with sedation (except EMG and nerve conduction)

How to prepare

• Ensure your child does not nap in the car on the way to the department. Even a short nap means your child or youth may not be tired enough to sleep during the test
• Do not bottle or breastfeed babies before the test
• Feeding after set-up can help calm children so they can fall asleep
• Please bring anything that normally helps your child relax (e.g. soother, bottle, blanket, stuffed animal, story book, music, melatonin, etc.). In most cases, children can take prescribed medication as usual on the day of the test. If you are unsure, check with your doctor
• If your doctor has told you to give your child melatonin, please bring it with you and wait until you are in the room before giving it to the child

We may use sedation if a child is unable to tolerate their test set-up while awake, or if sleep was not recorded on previous electroencephalogram (EEGs) and is important to the child's diagnosis. 

We do not routinely give sedation. If required, your doctor will order and pre-arrange this with our department. 

We use mild sedatives (dexmedetomidine), which we usually give intranasally. Sedation nurses will contact you in advance to complete the screening process. They will ask you questions about your child or youth's medical history and give you information about the test. 

If your child or youth has had an adverse reaction to these medications before, or you know they will be ineffective for sleep, please contact your doctor so we can make other arrangements. 

To note

A doctor must order a sedated test at the time they book the appointment, because we must have a nurse present to administer the sedation and monitor the child. We cannot sedate unless this has been pre-arranged.

• Please tell us if your child or youth has reacted poorly to sedation in the past
• No fasting is required
• Sleep deprivation is still required for sedated EEG tests