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 to your child. An EEG usually takes about 60 to 90 minutes.
Your child may need this test to check for signs of:
EEGs are usually done when children have developmental delays or symptoms such as loss of consciousness, abnormal movements or behavior. The EEG will help tell if seizures or other brain conditions are the cause of the symptoms. Your child’s healthcare provider may have other reasons to recommend an EEG.
Most medical procedures have some risks. Talk with your child’s healthcare provider 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 healthcare provider will treat it right away.
To prepare your child for an EEG:
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 healthcare provider know before the test. You may need to stop some medicines if they may affect the test results.
Follow instructions about when your child can eat before the procedure.
Follow instructions 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 healthcare provider 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. He or she puts 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. He or she 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.
The test takes about 90 minutes. Your child's healthcare provider may also order a video EEG to give more time to study the brain waves. The procedure is the same, but may last 6 to 8 hours or overnight.
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. Your child can return to his or her normal routine.
A neurologist will read the EEG and talk to your child's healthcare provider about the results. Schedule a follow-up appointment with your child’s healthcare provider to review the results of the test.
Let your child’s healthcare provider 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 will you get the results
Who to call after the test or procedure if you have questions or your child has problems
How much will you have to pay for the test or procedure