An electroencephalogram (EEG) is a non-invasive diagnostic test that records the electrical activity in your brain using small, flat metal discs (electrodes) attached to your scalp. Your brain cells communicate via electrical impulses and are active all the time, even when you’re asleep. This activity shows up as wavy lines on an EEG recording. The EEG test specifically measures the voltage difference resulting from ionic current within the neurons in the brain. The EEG test 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. Our EEG’s are recorded using the American Clinical Neurophysiologic Society (ACNS) guidelines and neurology clinic uses the International 10-20 System of electrode placement.

The ambulatory EEG test is very similar to the routine study, however, your physician will request that we record your brain activity on a portable device for a period of 24, 48, or 72 hours or longer. The extended recording greatly enhances our ability to help diagnose symptoms. They will most likely request that you record with a portable video device as well. You will be asked to keep a diary of activities for the duration of the recording period.

EEG testing is ordered for a number of neurological disorders. This type of testing is most often used in the diagnosis of seizures or epilepsy, headache, memory disturbances, stroke, spells, syncope (fainting) and other neurological symptoms. The ambulatory EEG is more often requested in order to capture some type of event, spell, seizure or suspected seizure to identify the cause of your symptoms or to rule out potential causes. There is a benefit in having you perform most of your usual daily living activities as sometimes your normal environment may trigger your symptoms.

For the ambulatory EEG test, your head will be wrapped after the electrodes application with several layers of gauze and a stocking type cap.

Patient Preparation

  1. Come to your appointment with clean, dry hair with no oils or heavy product on your hair. (If you have a weave, you should have it temporarily removed).
  2. There is no food or beverage restriction for the ambulatory EEG.
  3. Wear comfortable clothing and a button down shirt is recommended. For ladies, you may be comfortable with a tank top as well.
  4. You don’t need to be sleep deprived.
  5. Take normally prescribed medications unless otherwise directed by your physician.

What to Expect

The technician or technologist at our neurology center may ask you some questions about your history of symptoms, your handedness. This helps them to convey that information to the interpreting physician and may aid in the interpretation and diagnosis.

The technician/technologist will measure and mark your head with a grease pencil. This insures that the electrode placement is accurate. This pencil will come off after the testing.

You will be lying down on a table and we will try to ensure that you are comfortable and warm. The technician/technologist will then rub a gel on your scalp that feels rather gritty or scratchy at each electrode location as this step helps the electrodes make a good connection with the scalp. The electrode discs will be attached with a conductive paste and piece of special gauze made for longer term record. A second layer of this gauze will be applied with another type of paste that helps to secure the electrodes for the longer duration. At this time the technician/technologist will also measure the contact between the electrode and scalp. Electrodes will be placed on the upper chest/shoulder area to record your heart rhythm (EKG) as well.

You will be asked to lay relatively quiet and still for a few minutes of recording time and you will feel no sensations from the test and there is nothing harmful like radiation. The tech will ask you to open your eyes several times, ask you to answer some orientation questions out loud, and may give you a mental task or two to complete (simple subtraction etc.). If you are in good health and are able to perform, you may be asked to do a three-minute deep breathing exercise. This breathing exercise may make you feel a little lightheaded or dizzy, may give you a tingling sensation in your fingertips or around your mouth. Don’t be alarmed as this is a normal response and these sensations will go away shortly after you stop the deep breathing

You will either return to our neurology center or be asked to remove the electrodes at home after the completion of the study. It is important to return your diary back to the office, along with all of the equipment. Your scalp will be cleaned as best as we can with a damp washcloth. The tech will comb through your hair to remove the paste. There should not be any obvious telltale remains of the paste but you will wish to wash your hair when you have the opportunity 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.

Outside Physician Requests

If you would like to schedule a procedure with our office, please fax patient demographic information (including insurance), most recent patient history and physician notes along with an authorization if needed to our office at 602-258-3368. Our technologist or office staff member will contact the patient for scheduling

Should you have any questions regarding electroneurodiagnostic testing, feel free to contact our technologist, Renee Schwarz, R. EEG/EP T., C.M.E.T., R.NCST, CNCT, at 602-258-3354 at extension 132.