An electroencephalogram (EEG) is a test that measures the electrical activity in the brain (brain waves). Small, round discs with wires (electrodes) are placed on the scalp during the test. The electrodes are not painful for your child. An EEG usually takes about 60 to 90 minutes.

Your child may need this test to check for signs of:

• Seizures.
• Sleep apnea.
• Brain infection.
• Brain tumor.

EEGs are usually done when children have developmental delays or symptoms, such as loss of consciousness or abnormal movements or behavior. The EEG will help tell if seizures or other brain conditions are the cause of the symptoms. Your child's doctor may have other reasons to recommend an EEG.

Most medical procedures have some risks. Talk with your child's doctor about the risks and benefits of this test for your child.

The EEG has been used for many years and is considered a safe procedure. The test causes no discomfort. The electrodes record activity. They don't stimulate nerves. In addition, there is no risk of getting an electric shock.

In rare cases, an EEG can cause seizures in a person with a seizure disorder. This is because of the flashing lights or the deep breathing that may be involved during the test. If your child does get a seizure, the doctor will treat it right away.

To prepare your child for an EEG:

• In an age-appropriate and reassuring manner, explain the test to your child and why it's being done.
• Wash your child's hair the night before. Don't put any oil, gel, or hairspray on the hair. If your child's hair is long, don't braid it or put it up. Remove any hair extensions. They can interfere with the test.
• If your child is taking any medicines, let the doctor know before the test. You may need to stop some medicines if they may affect the test results.
• Follow directions about when your child can eat before the procedure.
• Follow directions about keeping your child awake the night before if your child needs to be sleepy during the test.
• On the day of the EEG, your child should not have any drinks with caffeine, such as caffeinated sodas, coffee, or tea.

To get the most information from this test, your child's doctor will try to record the EEG while your child is awake and asleep.

An EEG is done by a trained technologist. During the test, the electrical activity of your child's brain is recorded on a computer or printed on paper. The technologist may also use a video camera to record your child's physical activity. You can stay with your child in the testing room. Your child can bring a favorite toy, such as a stuffed animal, for comfort.

During the test:

• Your child will be asked to lie down.
• The EEG technologist measures your child's head and makes small marks on the scalp with a washable marker or pen.
• The technologist rubs each marked area with a gritty lotion so the electrodes transmit well. They put glue on the electrodes. The technologist puts electrodes on each of the marked spots on the scalp. The marking of the scalp and the application of the gritty lotion can be uncomfortable for some children.
• The technologist connects the electrodes to the EEG machine and begins the test. Your child will need to sit or lie as still as possible. They may be asked to breathe fast (hyperventilate), look at flashing lights, and try to sleep.

In rare cases, an EEG can cause seizures in a child with a seizure disorder. This is from the flashing lights or the deep breathing that may be involved during the test. If you notice signs that your child may be having a seizure, tell the technologist right away.

A typical EEG takes about an hour. Your child's doctor may also order a video EEG to give more time to study the brain waves. Under some circumstances, the EEG may need to be recorded longer, as much as a few days.

Once the test is done, the technologist removes the electrodes and washes off the glue with warm water and a washcloth. If some glue does not come off, you may need to wash your child's hair at home. Ask the technician the best way to remove the glue without causing discomfort.

Your child can return to their normal routine. If seizure medicines were held for the test, ask the doctor if they should be given after the test.

A neurologist will read the EEG and talk to your child's doctor about the results. Schedule a follow-up appointment with your child's doctor to review the results of the test.

Let your child's doctor know if symptoms or seizures get worse after the test.

Before you agree to the test or the procedure for your child, make sure you know:

• The name of the test or procedure.
• The reason your child is having the test or procedure.
• What results to expect and what they mean.
• The risks and benefits of the test or procedure.
• When and where your child is to have the test or procedure.
• Who will do the procedure and what that person's qualifications are.
• What would happen if your child did not have the test or procedure.
• Any alternative tests or procedures to think about.
• When and how you will get the results.
• Who to call after the test or procedure if you have questions or your child has problems.
• How much you will have to pay for the test or procedure.