An electroencephalogram (EEG) is a neurological test that measures electrical activity or brain waves. An EEG measures brain waves through small button electrodes that superficially attach to your child's scalp.
- How is the EEG performed?
- What steps should be taken to prepare my child for the EEG?
- What happens after the EEG?
- Are there any risks involved with the procedure?
- Who evaluates the EEG recordings?
- What is an ambulatory EEG?
- What is an Intracranial EEG?
- What is a Stereo EEG and Robot-Assisted Stereo EEG?
A trained neurophysiology technician will perform your child’s EEG. First, your child will be asked to lie down on a bed. Your technologist will then explain the procedure to both you and your child and answer any questions you may have about each part of the test. The technologist will then measure your child's head and make small marks on the scalp with a washable marker or pen. Each marked area is rubbed with a gritty lotion so the electrodes transmit well. Paste is adhered to the electrodes, which are placed on each of the marked spots on the scalp. At this time, the technician will connect the electrodes to the EEG machine and begin the test, measuring the activity in your child’s brain.
Your child will need to sit or lie as still as possible, and may be asked to breathe fast (hyperventilate), look at flashing lights or try to sleep. The test lasts approximately one hour and your child will be recorded throughout the procedure.
In some cases, a longer EEG may be ordered by your physician.
- Wash your child's hair the night before the test, but do not use any oil, gel, or hairspray. If your child's hair is long, do not braid or put it up, and no hair extensions please.
- To get the maximum information from this test, your child's doctor may try to record the EEG during wakefulness and sleep.
- Give your child their prescribed medications as usual, and bring a list of all the medications (dose and schedule) your child takes to the EEG Lab.
- Your child's doctors will give you instructions about when your child can eat before and after the procedure.
- On the day of the EEG, your child should not have any drinks containing caffeine, such as caffeinated sodas, coffee, and tea.
Once the test is complete, the electrodes will be removed and the glue washed off with warm water and a washcloth. Sometimes, all the glue will not come off and you may need to wash your child's hair at home.
The technologist or nurse will give you further instructions and tell you when you and your child may leave.
Experts in neurology have studied EEG for many years and report that it is a safe procedure with no apparent risks.
A neurologist with board-certification in Epilepsy Neurophysiology will interpret the EEG and send a report your child's doctor about the results.
For some patients, a longer EEG test may be ordered if the electrical activity causing seizures is not detectable during the standard one-hour EEG test. An option to achieving this extended recording is an ambulatory EEG. An ambulatory EEG is performed in a patient’s home over a one, two or three-day period. The device continually records brain activity during this time while the patient is both awake and asleep.
Children who require an ambulatory EEG will attend an appointment either at the Epilepsy Center or one of our partner sites where a technologist will place the electrodes on their scalp and connect them to a small recording device. The device is small enough that it can be worn comfortably on the patient as they go through their daily routine at home.
For some patients, the seizure activity is not able to be detected by electrodes placed on the scalp during a regular EEG. For these patients, an intracranial, Stereo-EEG or robot-assisted stereo-EEG may be required.
What is an Intracranial EEG?
An intracranial EEG uses electrodes placed directly onto the cortex of the brain to monitor electrical activity and identify areas of seizure activity. An intracranial EEG begins in the operating room where surgeons will perform a craniotomy, followed by the positioning of electrodes within the brain. After the surgery concludes, the patient will be admitted to the ICU for one night, followed by several nights of monitoring in the epilepsy monitoring unit (EMU). While in the EMU, doctors, caregivers, and family will meet and determine the best course of action. After the test concludes, the patient will return to the operating room to have the electrodes removed.
What is a Stereo EEG and Robot-Assisted Stereo EEG?
A stereo EEG is similar to an intracranial EEG but is slightly less invasive. Instead of a craniotomy, a surgeon drills small holes in the patient’s skull and inserts tiny wires into the brain for monitoring. A robot-assisted stereo EEG is the same procedure but uses advanced robotics during surgery to place the electrodes. Following the successful positioning of the electrodes, the patient will be admitted to the ICU for one night, followed by several nights of monitoring in the EMU. While in the EMU, doctors, caregivers, and family will meet and determine the best course of action. After the test concludes, the patient will return to the operating room to have the electrodes removed.