Electroencephalogram at Dell Children’s Medical Center

The electroencephalogram (EEG) is method of tracking and recording the electrical activity in the brain, which allows pediatric neurologists the ability to study the patterns of that activity for abnormalities. It’s most often used when diagnosing a seizure disorder such as epilepsy, but can used in any case where the patterns of electrical activity in the brain need to be observed.

What Is an Electroencephalogram?

Electrical activity in the brain is always happening, even during sleep. These electrical impulses are detected by the EEG as patterns of waves, with frequencies that can change depending on the conscious state of the brain. For instance, there are specific ranges of frequencies for both sleeping and waking that are considered normal.

When used to diagnose disorders in the brain, a pediatric neurologist will study the results of the EEG test looking for abnormal patterns and frequencies in these brain waves. They can also be used to identify sources of abnormalities, as different frequencies and patterns have been identified with specific causes.

Some common reasons for the detection of abnormal brain activity in an EEG are:

  • A seizure disorder such as epilepsy
  • Tumorous growth in the brain
  • Encephalitis
  • Dead brain tissue resulting from the blocked flow of blood
  • Hemorrhaging in the brain

There are many causes of abnormal brain activity, so frequently doctors and pediatric neurologists will also use other tests in conjunction with an EEG to determine the source of abnormal activity.

How Does an EEG Work?

The EEG measures the electrical impulses through electrodes attached to the child’s scalp. Placing these electrodes is painless; an electrode is simply a wire attached to a suction cup which is attached to the child’s head using hypoallergenic glue.

Though most EEGs take a few hours and are performed by the pediatric neurology team, in some cases a doctor may order a much longer test that lasts for a day or two. However, not all these extended tests require a hospital stay. Some children are able to use portable devices that record their brain activity while they go on with their normal routine at home.

Because low blood sugar can affect the results of an EEG, fasting is not usually recommended before the test. EEGs performed at the pediatric neurology clinic typically involve tests such as breathing exercises and having a light flashed in the child’s eyes in order to trigger activities in the brain that will give the neurologist the data they need.

Who Benefits from Receiving an EEG?

Although EEG tests are particularly useful for children that experience seizures, they can also be used to diagnose a wide variety of problems in the brain. When a doctor believes a condition in a child is being caused by a problem in the brain, an EEG can help guide their conclusions and diagnosis.

Aside from helping to determine a diagnosis, EEGs are also useful when observing the effects of treatments in those with brain problems. When changing a child’s diet or medication, a follow-up EEG can help determine how effective the change has been in resolving symptoms.