EEG (Electroencephalogram)

What is an EEG?

An EEG (electroencephalogram) is a test that records the electrical activity of your child’s brain. (The nerve cells in your child’s brain work by carrying tiny electrical charges.)

When is it used?

An EEG can help your child’s healthcare provider diagnose medical problems such as:

• epilepsy
• sleep apnea or other sleep problems
• encephalitis (infection in the brain)
• brain tumors

An EEG can help healthcare providers decide on the best medicine to treat epilepsy. This test is sometimes used during surgery to check the effect of anesthesia. It may be used to test for brain death in cases of severe injury or illness.

How do I prepare for an EEG?

Your child’s head doesn't need to be shaved for an EEG. Some EEG labs ask that your child’s hair be clean and free of hair products such as hairspray or mousse. On the day of the EEG, your child should not have any drinks that containe caffeine (such as sodas, sports drinks, or tea).

Ask your child’s provider if there are any special instructions your child needs to follow. Also ask if there are any substances or medicines that your child should avoid before the test.

Sometimes a sedative is given just before the test to help your child relax during the EEG.

What happens during the test?

An EEG normally takes 45 to 60 minutes. During the test your child will relax in a bed. Small metal plates (electrodes) are pasted or taped to your child’s head. The electrodes send information to a machine that records brain waves on paper. Young children do not like the feel of the electrodes, but it doesn’t hurt except when the electrodes are removed.

EEGs may be done while your child is:

• sleeping (Your child may be given a medicine to help your child sleep).
• resting with eyes closed (for babies, this may be done by placing a hand over the baby’s eyes and playing peek-a-boo)
• resting with eyes open
• breathing rapidly (and just after)
• looking at a flashing light.

The EEG records how the brain responds to these changes. Your child may have a video EEG instead. This gives more time to study the brain waves. A video EEG may take 6 to 8 hours, or be done for 24 hours.

What happens after the test?

Your child can usually go home as soon as the test is done.

What are the benefits and risks of this test?

This test helps your child’s healthcare provider diagnose certain medical conditions. There are no risks.

When should I call my child’s healthcare provider?

Call your child’s provider right away if your child has any change or worsening of symptoms after the test.