Electroencephalogram (EEG)

Detecting and monitoring electrical activity in the brain

An electroencephalogram (EEG) monitors brain activity. The non-invasive test detects what happens during a seizure or other brain event. An EEG can be done in the hospital or in an outpatient setting.

What to Expect with Electroencephalogram (EEG)

If you have been diagnosed with seizures or epilepsy, your physician may recommend an EEG. You may also have an EEG if you are going through the process of diagnosing issues related to your brain. An EEG test measures and monitors electricity in the brain to determine what is happening during a seizure or other event.

Types of EEG

There are two types of EEG:

EEG

This 30-minute test is completed in the outpatient or inpatient setting. Your physician will review results from this initial test to make a diagnosis, plan treatment, or decide if more testing is needed.

Video EEG

If your physician needs more information about your brain activity, you may undergo a video EEG (VEEG). A video EEG is performed in the epilepsy monitoring unit (EMU).

This overnight test captures your behavior using audio and video recordings. It also monitors your brain’s electricity. VEEGs incorporate standard EEG and include video and audio monitoring. The VEEG can last anywhere from 24 hours to five days. During this time, you are monitored in a hospital setting. That way, your physician can track your brain activity during awake and sleep cycles.

During an EEG

When you arrive for your EEG or VEEG, an EEG technologist will explain to you what will happen. He or she then will begin connecting you to the EEG machine. This involves having you either lie down or sit up in a reclining chair. You can expect a technologist to:

  • Measure and mark the size of your head to determine where to place the electrodes
  • Mark the electrode sites with a washable marker
  • Clean the contact spots for each electrode
  • Place disc-shaped electrodes on the scalp or face
  • For overnight exams, glue will be applied to keep the electrodes secure

During the exam you will be asked to:

  • Open and close your eyes
  • Perform a photic stimulation using a strobe light in front of your closed eyes
  • Perform a deep-breathing test
  • Rest and fall asleep, if possible, to monitor the various stages of sleep.

Helpful Reminders About EEG

  • Your hair will not be shaved during this process. We can measure brain activity through your hair.
  • Electrodes only monitor and receive information from your brain waves. Electrodes do not deliver any electricity to your body.
  • If your test requires an overnight stay, you will be kept in your bed and permitted to use the restroom with help from your care team.

Prepare for Your EEG

  • Hair should be clean and dry before the EEG
  • Remove any hairpins or braids from your hair
  • Arrive sleepy or ready for a nap, if possible

What Should I Bring With Me to an Overnight EEG?

Please bring with you to the hospital:

  • Medications. Bring all your medications with you in their original prescription containers.
  • One other adult may accompany you to your VEEG and stay in your room overnight
  • Comfortable clothing. Shirts or pajamas that button or zip up the front are required
  • CPAP/BIPAP apparatus (if required at home)
  • Personal items such as toothbrush, toothpaste, shampoo, conditioner and sanitary items.
  • Comfort items like your own pillow, blanket or snacks, if you have preferences.
  • Other items to help pass the time can include portable devices, books, cards, games, puzzles or other stationary activities

After Your EEG

Once your test is complete, the electrodes and glue will be removed from your head. A specially trained neurologist will review your test and send the results of your EEG to your physician’s office. Your physician will discuss the next steps with you.

Treatment

After your EEG, your physician may recommend a variety of treatment options, depending on your diagnosis. These may include:

  • Medication
  • Ketogenic diet
  • Surgery
  • Other therapies

Locations

IU Health offers EEGs at hospitals around the state. These include:

Patient Stories for Electroencephalogram (EEG)

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