Electroencephalogram (EEG)

Electroencephalogram (EEG)

Location and Contact

Phone (patient scheduling office): 905-472-7020
When you arrive at Markham site: Register at the registration desk in the main lobby. The registration desk clerk will direct you to your test or procedure.

An electroencephalogram (EEG) test involves the recording and analysis of electrical signals generated by the brain. There are two types of EEGs that a doctor may order: routine and sleep-deprived. A sleep-deprived EEG is where you stay awake much of the night before your EEG.

This test is used to help diagnose conditions such as seizures, head injuries, dizziness, syncope, headaches and epilepsy.

To have an EEG, your doctor needs to fill out a requisition form. Download EEG requisition form.

Learn more about making an appointment and coming to the Markham site.

An EEG is performed by an EEG technologist.

Before your EEG

For a routine or sleep-deprived EEG:

Shampoo your hair on the morning of the test. Do not use gel, mousse, sprays, etc. Bring all current medications with you. Have meals as usual but exclude caffeinated products. Caffeine products include coffee and tea (decaffeinated and caffeinated), chocolate, cocoa, pop, energy drinks and any medication or supplements that may have caffeine.

Additional information or a sleep-deprived EEG:

Adults and children over 12 years of age must stay awake from midnight before the test.

You should book children 12 months to three years of age during their naptime. Four- to eight-year-olds should be awake from 4 a.m.; nine- to 12-year-olds from 2 a.m.

During and after your EEG

During your test, the technologist will make some special markings on your head with a pencil to help guide where to put the electrodes. He or she will attach electrodes to these spots using gel paste. The electrodes will be attached by wires to a machine that the technologist will use to monitor your brainwaves. The entire process might be a bit uncomfortable but it should not hurt.

After your test, the technologist will remove the electrodes. You may still have some gel paste in your hair that you will need to wash out later.

Frequently asked questions about EEG

How long will the test take?

The test will take between 60 and 90 minutes.

Are there any side effects to this test?