Individualized,
compassionate care
for pain

Browse >

24-Hour Electroencephalogram (EEG)

how to prepare and what to expect from your 24-hour eeg

A 24-hour EEG measures the brain's electrical activity (brain waves) over a 24-hour period. It is used to diagnose and monitor seizure activity or to help evaluate brain tumors and other neurological conditions.

How to Prepare

When you schedule your 24-hour EEG, you will be told whether the procedure will be performed on an inpatient or outpatient basis. If it is to be performed on an outpatient basis, please arrive at the time and location given to you. You can expect to go home within an hour or two after preparations for the test are made. You'll need to return the next day for follow up.

If you will be admitted to the hospital for this procedure, please arrive at the time and location given to you. You will be discharged from the hospital the next day.

You will be asleep during much of this test, so please bring sleep wear unless you would prefer to wear a hospital gown.

The evening before or morning of your appointment, wash and dry your hair, but do not apply spray, oil, mousse, or cream.

You may eat and drink as usual and remain active right up until the time of your 24-hour EEG.

What to Expect

You will be escorted to the EEG testing area, where an EEG technologist will place eight to 10 small disks (electrodes) on your scalp with a glue-like adhesive. These electrodes will be connected to a small, lightweight cassette tape recorder that attaches to a strap or belt around your shoulder or waist. This equipment records your brain waves.

Set-up time for this test takes about 60 minutes and is painless. Afterward, you will either be discharged or be taken to a hospital room. In either case, you will need to relax and sleep for the next 24 hours. You'll be given a diary in which to record all your activities, any abnormal sensations, or seizures you may experience.

After the testing period is complete, you will return to the EEG testing area, where an EEG technologist will remove the electrodes and recording equipment. You may resume your normal activities immediately.