Electroencephalogram

What you should know

• An electroencephalogram (e-lek-tro-en-SEF-ah-lo-gram) is usually called an "EEG". An EEG measures the electrical activity made by your brain. A machine or a computer is used to make a tracing that shows the electrical activity as "brain waves". Caregivers study this tracing to learn about your brain and how it is working. You will not get a shock from having an EEG. The machine or computer cannot "read your mind".
  
  
• EEGs can help caregivers learn about epilepsy (EP-i-lep-see). Epilepsy is a condition where you may have unusual electrical rhythms. These unusual rhythms may cause seizures (convulsions). EEGs also help caregivers learn about sleeping problems, brain injury, brain tumors, and many other problems.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

Risks

If you have seizure (SEE-zhur) problems, the flashing light or other things may cause a seizure during the EEG. Caregivers will be there to help you. If you do not have this test, caregivers may not be able to treat your illness.

Getting Ready

• Some medicines should not be taken before having an EEG. These may include medicines that help you relax or sleep such as sedatives (SED-ah-tivs) and tranquilizers (TRAN-kwi-li-zers). These may include anti-seizure medicines or stimulants such as antihistamines (an-ti-HIS-tah-mins). Take a list of your medicines, or the medicine bottles to your caregiver. Ask your caregiver if any of your medicines should not be taken before your EEG. Do not stop taking any medicines without asking your caregiver first.
  
  
• Your caregiver may need you to have a sleep-deprived EEG. Sleep-deprived means that you will not get your usual amount of sleep the night before your EEG. Sleep-deprived EEG's may be done in two ways:
  
  
  • You may be told to sleep a certain number of hours, then set your alarm to wake up. You will then need to stay awake the rest of the night.
    
    
  • You may be told to wake yourself up at a certain time. If so, you may go back to sleep.
  
  
• If you will not be having a sleep-deprived EEG, sleep as usual the night before the EEG.
  
  
• Wash your hair before the EEG. Do not put any hair spray, oil, or conditioners on your scalp or head. Your scalp and hair must be free of all of these during the EEG.
  
  
• Avoid drinking any caffeine the morning of the test. This includes coffee, tea, colas, and cocoa. Some sodas have caffeine in them. Read the ingredient label on the can or bottle before drinking any soda on the morning of the test. Caffeine may change the result of your EEG.
  
  
• Eat your regular breakfast or lunch before the EEG. Eating your normal meals will prevent your blood sugar from dropping too low. Having low blood sugar can change the result of your EEG.
  
  
• Ask if your caregiver plans to give you a sleeping pill during the EEG. If so, you may feel very drowsy (sleepy) after the EEG. Ask a friend or family member to drive you home after the EEG.

Treatment

• Your EEG will be done in a room that is dark and quiet. You will either lie in a bed or sit in a reclining chair during the test. A caregiver will measure your head and scrub (clean) 20 to 21 areas of your scalp. Then, a gel or cream will be placed on these areas. Electrodes (patches) or tiny needles that you will not feel will be placed on the gel or cream. The electrodes will be connected with wires to a machine or computer. An electrode may be put on each earlobe.
  
  
• Lie very still with your eyes closed. Try to relax. Do not talk during the test. The EEG machine or computer will record your brain waves. During the EEG, you may be asked to hyperventilate (hi-per-VEN-ti-late). This means you may need to breathe deeply and quickly for three to four minutes. You may be asked to look into a bright flashing light (strobe light). If caregivers want you to be asleep, they will give you medicine to help you sleep during the EEG. You may be videotaped during the EEG. After the EEG, caregivers will remove the electrodes, wires, and gel or cream. Most EEGs are done in 90 minutes or less.

Contact a caregiver if

• You cannot make it to your EEG appointment on time.
  
  
• You have questions or concerns about your EEG.
  
  
• You have a fever.
  
  
• The problems for which you are having the EEG get worse.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.