EEG and What to Expect for Children With Angelman Syndrome

Emily Malcolm, PhD avatar

by Emily Malcolm, PhD |

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MRI for Angelman syndrome

Angelman syndrome is a rare genetic disease characterized by delayed development and motor difficulties. The symptoms of this neurological disorder can appear early in life, but the diagnosis is often a lengthy and challenging process.

An electroencephalogram (EEG), a test which measures electrical activity in the brain, can be used to diagnose and monitor disease progression. Children with Angelman may have to undergo the test at intervals throughout their lives.

What happens during an EEG?

An EEG uses soft electrodes placed on the scalp to measure brain activity. The technician will mark the locations of the electrodes with a soft crayon on your child’s head. A gritty paste will then be used to attach the electrodes in these locations.

The test takes about 60-90 minutes, and should not cause any pain or discomfort. Your child usually will have to lie still and quiet during the test. The lights will be dimmed, and the room will be quiet, so your child is able to rest or nap during the test. In some cases, your child’s doctor may want an overnight EEG, which is a longer process, usually lasting six to eight hours.

While rare, the flashing lights and deep breathing during the test can induce seizures in children who have seizure disorders. Be sure to inform the technician beforehand if your child has had seizures so they can provide appropriate medical care during the procedure.

How to prepare?

Wash your child’s hair the night before the EEG. However, do not use any hair products such as conditioner, spray, or styling gel, as they can interfere with the electrodes during the EEG.

Talk to your doctor about whether your child needs to discontinue any medications before the test. Some medications can interfere with measurements.

Don’t give your child any caffeine or chocolate on the day of the test. Patients can not eat or drink during the test, so make sure your child has eaten earlier in the day. Your clinic will tell you if there are any dietary restrictions that your child should adhere to prior to the test.

If possible, have your child use the bathroom before the test begins.

Some clinics will instruct you to keep your child up two hours later the night before the test, and wake your child two hours earlier than usual on the day of the test. That may make it easier for your child to nap during the testing. Your clinic will give you specific instructions.

What happens afterward?

Once the test is over, the technician will remove the electrodes and wash the glue from your child’s hair with warm water and a washcloth. Some glue may remain, however, so you may want to wash your child’s hair again when you return home.

Your child can return to his or her normal routine. There are no special precautions following an EEG.

Your child’s EEG results will be given to a neurologist, who will examine the patterns. These can reveal important information about your child’s symptoms and disease progression.

Once the EEG results have been examined, the neurologist will meet with you to discuss the findings. Based on the results, your doctor may recommend additional testing or changes in medication for your child.


Last updated: June 25, 2020


Angelman Syndrome News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.