An electroencephalogram (EEG) is a test that records your brain rhythm. It is similar to an ECG (Electrocardiogram) that records your heart rhythm.
Our brain cells work by sending electrical impulses to each other all the time, even when we are asleep. This activity shows up like waves and lines on an EEG recording.
Why did my child’s doctor ask for an EEG?
- An EEG is done to determine if your child is having active seizures or at the risk of having seizures.
- A seizure is a burst of electrical activity in the brain. Therefore, an EEG is one of the main diagnostic tests if your doctor suspects a seizure disorder/epilepsy.
An EEG is done for other brain disorders as well, such as
- Brain tumor
- Brain damage from a head injury
- Brain dysfunction can have a variety of causes (encephalopathy)
- Infection/Inflammation of the brain (encephalitis)
- Sleep disorders
How to prepare
- Continue your child’s medications as advised. Do not stop any anti-seizure medications unless your doctor tells you to.
- Wash your child’s hair the night before or the day of the test. Oily hair can make it harder to attach the electrodes to the scalp.
- Sleep deprivation – In the case of older children, allow only 4-5 hours of sleep the night before the study so that the child may fall asleep easily during the test.
- There is no need to fast – make sure your child has eaten well prior to the test.
- Avoid falling asleep on the way to the hospital!
On the day of the test
- Arrive 30 minutes before your scheduled appointment.
- It will give you time to register. In addition, your child may be given a sedative which takes time to work.
- Bring your child’s file as well as any EEG reports done previously.
During the test
- The technologist will measure the head and mark your scalp with a special pen to indicate where to attach the electrodes. Those spots are scrubbed with cream to improve the quality of the recording.
- Small disc-like electrodes are applied to the scalp using a special adhesive. The electrodes are connected with wires to an instrument that records them on the computer.
- Once the electrodes are in place, an EEG typically takes up to 20-40 minutes.
- In certain cases, your doctor may ask for a longer recording (one to several hours).
- Recording is done when the child is asleep as well as awake.
- At various times, the technologist might ask your child to open and close eyes, recite numbers, breathe deeply for a few minutes, or look at a flashing light.
- Video is routinely recorded during the EEG. The child’s movements are captured by a video camera while the EEG is recording the brain activity.
- This combined recording can help your doctor diagnose and treat your condition.
- EEGs are totally safe and painless!
- Your child will be monitored by the Technologist throughout the study.
After the test
- The technologist removes the electrodes. Any residual cream in the hair will be easily washed off by a hair wash at home.
- If a sedative was given, it will take time for the medication to begin to wear off.
- Your child may be irritable, sleepy for a few hours after the test.
- Do not feed your child till he/she is completely awake.
Doctors trained to analyse EEGs interpret the recording will report the test. Your child’s doctor might schedule a clinic appointment to discuss the results of the test.