by Editorial Staff and Contributors
Electroencephalogram (EEG) is a test used to look at the electrical activity in the brain.
Reasons for Test TOP
An EEG may be done to:
Possible Complications TOP
There are no major complications associated with this test.
What to Expect TOP
Prior to Test
Depending on the reason for your EEG, you may be given some of the following instructions:
Description of Test
You will sit in a chair or lie on a bed. Electrodes will be placed on your scalp with special gel or paste. The electrodes will record the brain's electrical activity. You will be asked to close your eyes and be still for most of the test. Depending on the reason for the test, there may be other steps such as:
In some cases, a video recording of the test will be made.
After Test TOP
The technician will remove the electrodes and you will be able to go home.
Talk to your doctor about restarting any medications that you may have stopped.
How Long Will It Take? TOP
The test may take about one hour. In some cases, an EEG is done overnight or over a number of days. The test may be done at home or in the hospital.
Will It Hurt? TOP
No, an EEG is painless.
Your test results will be reviewed. Your doctor will get a report within 1-2 weeks and will talk to you about the results.
Call Your Doctor TOP
Call your doctor if you have a seizure disorder and your regular seizure pattern changes when you restart your anti-seizure medication.
National Institute of Neurological Disorders and Stroke
Canadian Neurological Sciences Federation
EEG (electroencephalogram). Nemours Kid's Health website. Available at:
...(Click grey area to select URL)
Updated September 2013. Accessed February 13, 2014.
Seizure in adults. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T114746/Seizure-in-adults. Updated April 11, 2016. Accessed October 10, 2016.
Seizure in children. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T550165/Seizure-in-children. Updated April 11, 2016. Accessed October 10, 2016.
Shevell M, Ashwal S, et al. Practice parameter: Evaluation of the child with global developmental delay: Report of the Quality Standards Subcommittee of the American Academy of Neurology and The Practice Committee of the Child Neurology Society. Neurology. 2003;60:367-380.
Last reviewed January 2015 by Rimas Lukas, MD
Last Updated: 2/14/2014
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