An electroencephalogram (EEG) is a non-invasive diagnostic test that monitors and records the electrical activity and brain wave patterns of your brain. Your brain cells communicate via electrical impulses and are active all the time, even when you’re asleep. This activity appears as wavy lines on an EEG recording. The EEG specifically measures the voltage difference resulting from ionic current within the neurons in the brain.

The EEG is different than an MRI or CT scan as those tests show physical structures of the brain or spine, and the EEG records the physiologic portion or electrical connections of the brain.

1. Please have clean, dry hair with no hair products, particularly oils.
2. Refrain from having caffeine the day of your test.
3. You are encouraged to eat your meals prior to EEG procedures.
4. Try to get a few hours less of sleep the night before testing as we would like you to be a little tired. If you normally get 8 hours of sleep at night, try not to get more than 6. However, it is not necessary to stay awake all night unless otherwise instructed.

An EEG typically takes 1 hour.

At the completion of the study, the electrodes will be removed, and your scalp will be cleaned with a damp washcloth. The technician will comb through your hair to remove any remaining paste. There should not be any obvious remaining paste, but if there is, you will need to wash your hair to remove any sticky residue.

A physician will interpret the study afterward and a report will be sent to your referring provider. Expect to hear from your ordering physician/provider after the test.

After the test is completed, you are free to resume your normal activities. If you were sleep-deprived, you may want someone to drive you home after the test.

EEG testing is most often ordered to study the brain activity for any potential neurological disorders, such as:

• Seizures or epilepsy
• Headache
• Head Injuries
• Memory disturbances
• Stroke
• Spells
• Syncope (fainting)
• Tumors
• Encephalitis (brain inflammation)

An EEG is a painless test. You will not feel anything abnormal during the recording. You will be asked to lie flat on your back on the examination table, and our staff will ensure that you are comfortable and warm.

To begin, the technician may ask you some questions about your history of symptoms, your handedness, etc. The technician will then measure and mark your head with a grease pencil. This ensures that the electrode placement is accurate. This pencil will come off after the testing.

Next, the technician will apply a conductive gel that will allow the electrodes to connect effectively. 24 electrodes will be applied to different areas on the head and chest. Your heart rhythm (EKG) will be recorded as well, and electrodes will be placed on the outer portion of your eye to record eye movements.

During the test, you will be subjected to different forms of neural stimulation; for example, you may be asked to open your eyes several times, you may be asked some orientation questions out loud, and may be given a mental task or two to complete (simple subtraction, etc.). You may be asked to do a three-minute deep breathing exercise. You may be asked to go to sleep. The technician may flash a bright strobe-light over your eyes intermittently for several minutes.

The purpose of this testing method is to gauge how your brain reacts to these types of stimuli.