Child Electroencephalography (EEG)

(Electroencephalography, Brain Wave Test)

Procedure Description

What is an EEG?

An electroencephalogram (EEG) detects abnormalities in the brain waves or electrical activity of the brain. During the procedure, electrodes consisting of small metal discs with thin wires are pasted on the scalp. The electrodes detect tiny electrical charges that result from the activity of the brain cells. The charges are amplified and appear as a graph on a computer screen or as a recording that may be printed out on paper. Your physician then interprets the reading.

Related procedures that may be performed are evoked potential studies. These studies are used to measure electrical activity in the brain in response to stimulation of sight, sound, or touch. Please see this procedure for additional information.

During an EEG, typically about 100 pages of activity are evaluated. Special attention is paid to the basic waveforms, but brief bursts of energy and responses to stimuli, such as light, are also examined.

Reasons for the Procedure

The EEG is used to evaluate several types of brain disorders. When epilepsy is present, seizure activity will appear as rapid spiking waves on the EEG.

Patients with lesions of the brain, which can result from tumors or stroke, may have unusually slow EEG waves, depending on the size and the location of the lesion.

The EEG may also be used to determine the overall electrical activity of the brain (e.g., to evaluate trauma, drug intoxication, or extent of brain damage in comatose patients). The EEG may also be used to monitor blood flow in the brain during surgical procedures.

There may be other reasons for your physician to recommend an EEG.

Risks of the Procedure

The EEG has been used for many years and is considered a safe procedure. The test causes no discomfort. The electrodes only record activity and do not produce any sensation. In addition, safety features are in place to prevent your child from getting an electric shock.

In rare instances, an EEG can cause seizures in a child with a seizure disorder due to the flashing lights or the deep breathing that may be involved during the test. There may be other risks depending upon your child’s specific medical conditions. Be sure to discuss any concerns you have with us prior to the procedure.

Certain factors or conditions may interfere with the reading of an EEG test. These include, but are not limited to, the following:

• low blood sugar (hypoglycemia) caused by fasting
• body or eye movement during the tests
• lights, especially bright or flashing ones
• certain medications, such as sedatives
• drinks containing caffeine, such as coffee, cola, and tea
• oily hair or the presence of hair spray

Patient Preparation (Child)

Please arrive 10 minutes prior to your appointment at the NeuroLab on the second floor of Raleigh Neurology.

Note: This is a generic pediatric preparation and changes might be made depending on your child’s age, demeanor or personality.

• Please have your child go to bed 2 hours later than usual the night before the test and get up 2 hours early the following morning of the test. No more than 4-5 hours of sleep in total. We want the child to be sleepy upon arrival to the lab. No sleeping or napping on the day of testing. Keep the child awake while traveling from the home to Raleigh Neurology.
• Hair must be washed and clean. No sprays or gels, oils, or mousse should be applied to your child’s clean hair.
• No fingernail polish on fingers or toes, because of monitoring child’s pulse rate (if sedated).
• No caffeine (soft drinks, chocolate, coffee) 8 hours prior to the test.
• This applies to children under 5 years of age: If being sedated, feed 4 hours prior to testing. If the child gets hungry during the 4-hour fasting block, feed them clear liquids only (such as apple juice or Jello).

During the Procedure

Generally, an EEG procedure follows this process:

• Your child will be asked to relax in a reclining chair or lie on a bed.
• Between 8 and 20 electrodes will be attached to their scalp with a special paste, or a cap containing the electrodes will be used.
• Your child will be asked to close their eyes, relax, and be still.
• Once the recording begins they will need to remain still throughout the test. The child will be monitored through a window in an adjoining room to observe any movements that can cause an inaccurate reading, such as swallowing or blinking. The recording may be stopped periodically to let them rest or reposition themselves.
• After the initial recording performed at rest, they may be tested with various stimuli to produce activity that does not show up while they are resting. For example, they might be asked to breathe deeply and rapidly for three minutes, or they may be exposed to a bright light.
• If your child is being evaluated for a sleep disorder, the EEG may be performed while they are asleep.

After the Procedure

Once the test is completed, the electrodes will be removed and the electrode paste will be washed off with warm water, acetone, or witch hazel. In some cases, you may need to wash the child’s hair again at home.

If any sedatives were taken for the test, we may want your child to remain at our office until the sedatives have worn off.

Skin irritation or redness may be present at the locations where the electrodes were placed, but this will wear off in a few hours.

Your physician will inform you when to resume any medications you stopped giving your child before the test.As well, we may give you additional or alternate instructions after the procedure, depending on your child’s age or particular situation.

Frequently Asked Questions about EEG

Q. Does it hurt?

A. There is generally little or no discomfort

Q. How long does it take?

A. Generally it takes about 30 to 60 minutes?

Q. What conditions are being evaluated?

Useful links about EEG

The content provided here is for informational purposes only, and was not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your physician. Please consult your physician with any questions or concerns you may have regarding your condition.

This page contains links to other Web sites with information about this procedure and related health conditions. We hope you find these sites helpful, but please remember we do not control or endorse the information presented on these Web sites, nor do these sites endorse the information contained here.

American Academy of Neurology

Brain Aneurysm Foundation

Brain Injury Association

Brain Tumor Society

Epilepsy Foundation

National Brain Tumor Foundation

National Center for Injury Prevention and Control

National Institute of Neurological Disorders and Stroke

National Institutes of Health (NIH)