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​Cardio Respiratory

Electroencephalogram (EEG)

Note: Total appointment time is approximately 45 minutes


  Come to your appointment with clean hair (no spray, mousse or gel)
  Sleep deprivation either 1 hour or 24 hours (depending on the doctor’s recommendation)
  No restrictions on food intake
  Take medications as usual



An EEG is a recording of the brain function performed on patients of all ages. The Technologist will measure the patient's head to establish where to apply the electrodes (small gold-plated cups attached to a long thin wire). Patients relax on a comfortable bed and the wires are attached to the head and chest by a small amount of conductive cream. Each wire covers a specific area of the brain and monitors speed, amplitude and shape of the brain waves. The eye movements and heart rate are also monitored.

Many patients will be asked to breathe deeply at the beginning of the test to change the levels of oxygen and carbon dioxide. This allows the Technologist and Physician to see any changes that occur in the brain with this activation. The Technologist will record a portion of relaxation or sleep to establish any irregularities that occur in this stage. The Technologist usually ends the recording with photic stimulation. A strobe light is placed over the patient's head and flashes at different frequencies.

When the recording is complete the Technologist will remove the wires and clean off any excess cream. The recording of the brain waves will be analyzed and a report sent to the ordering doctors. This takes approximately three business days.

EEGs are ordered for many reasons. Here is a list of the most common ones:

•  An unexplained fall
•  Loss of consciousness
•  Confusion
•  Headaches
•  Seizures
•  Strokes
•  Head injuries
•  Learning or developmental delay
•  Hallucinations
•  Time loss or blanking out spells



Is this test harmful?

No. This is a test that can be done many times. There is no harm to the patient at any time.

Do I have to take off my wig?

Yes. The door is closed for privacy and no one will see you with your wig off. You can re-apply the wig when the test is over before you leave the room.

What if I can't keep my child relaxed and quiet?

The Technologists are very experienced. They have toys and other devices to help keep your child happy. Parents can sit on the bed with their child and can help to make their child feel at ease. Occasionally, extra pairs of hands are needed with toddlers. Be assured that the test is not painful and at no time does the child feel anything.

My child has autism, do you sedate patients with special needs?
The Technologists will always want to attempt an EEG without sedation. This is because with sedation only sleep brain waves are seen and no active awake activity is available. Many different symptoms occur in different stages of arousal and with sedation this is limited to sleep only. All pediatric children are sent to The Hospital for Sick Children in Toronto if they require sedation, however, melatonin as advised by the pediatrician may be used.



Epilepsy Ontario
Healthy Ontario
Alzheimers Society of Canada
Health Canada - Autism Information