Ambulatory EEG

Why do I need Ambulatory EEG Monitoring?

Epilepsy is a disease of the brain caused by abnormal electrical activity. Ambulatory EEG monitoring enables your doctor to observe your EEG over a prolonged period of time. Ambulatory monitoring can help diagnose your seizure type and provides important information regarding the best treatment for your seizures.

What will happen when I am set up for monitoring?

Placement of the EEG wires for monitoring

EEG wires will be attached to your head with a special glue so that the electrodes will stay attached for several days. Sometimes, the electrodes can cause some itching to occur and you can take medication to help the itching. Do not scratch your head with the electrodes in place. Benadryl 25 mg to 50 mg can be used for itching. This can be obtained over the counter at your local pharmacy.


Please do not eat potato chips or other snack foods or chew gum, since this will interfere with the EEG – it generates a lot of “noise” on the graph which makes it impossible to detect anything else.


You should wear comfortable clothing while your ambulatory EEG is being performed. Sweat pants and a loose fitting top with buttons down the front are suggested. Tight fitting sleeves and pull over tops will not be permitted. Do not attempt to pull a shirt or other clothing over your head during the ambulatory EEG. The electrodes may become dislodged and the quality of the recording will be affected.

What do I need to do before my test?

  • Assemble enough comfortable, appropriate clothes to wear. Most patients wear street clothes or a sweat suit during the day and warm pajamas and socks at night. Remember that the tops should button and be loose fitting.
  • Before the test, bathe and wash your hair well. Do not leave any hair products in your hair and remove any braids or hair extensions. This will facilitate comfortable placement of the electrodes

What is Ambulatory EEG Monitoring?

EEG is the abbreviation for electroencephalography. The electroencephalograph is a machine that translates the electrical activity of the brain into a series of wavy lines (a graph) on a computer called the EEG record. An EEG measures the electrical activity of the brain, sometimes referred to as brain waves. This test is performed to see how the different parts of your brain function. It records a graph of your brain waves. It can tell us what may be causing your episodes and help with deciding the best treatment for you. The doctor can see seizure activity as well as sleep stages during your EEG.

Digital analysis is a procedure that can give additional information about any problems that may be found. Analysis and examination of the data obtained allows your doctor to see one of the many ways that your brain functions.

EEG is not a treatment of any kind. No electricity is transferred to your brain. The EEG only detects activity in the brain. If you have a seizure during the test, you should behave as you normally would during a seizure. Family and friends should follow your usual first aid or emergency procedures.

The ambulatory EEG is a very expensive (~$20,000) piece of equipment that allows us to monitor a 24 hour period of brain waves but allows you to continue with most of your daily activities. Do not get it wet. Do not allow the box to get hit or banged against other objects. Do not attempt to adjust anything on the device and do not adjust the wires. You will be held responsible for any damages.

How does an Ambulatory EEG work?

Small, non-invasive metal cups called electrodes (usually 16 to 32 in number) are pasted on the scalp, after careful measurement by a trained technologist. The paste or glue is to keep the electrodes firmly in place. If the electrodes are moved, then the quality of the recording will be poor. The electrodes pick up very small changes in brain electrical activity. The activity is amplified and recorded on the computer. It is then translated into a complicated graph. During this procedure, the EEG is recorded for a prolonged period, allowing you to have a comprehensive EEG at home. You will need to keep a diary with exact times to correlate behavior with events on the EEG. Do not forget to use the button to mark the time of your events. This helps to determine the cause of any seizures.

How will I get my results?

After the technologist completes your study the doctor will review the study and discuss it with you at your next visit. If there are issues regarding the EEG of immediate concern, the doctor will contact you for further testing or discuss the findings with you on the phone. Do not ask the EEG technologist to interpret or explain your results. The EEG technologist will contact the physician if your EEG shows something that may be of immediate concern.

Neurodiagnostic Testing of the Brain, Spine & Nerves