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Electroencephalography (EEG)

Electroencephalography (EEG) Introduction

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The electroencephalogram (EEG) is a measure of brain waves. It is a readily available test that provides evidence of how the brain functions over time.

  • The EEG is used in the evaluation of brain disorders. Most commonly it is used to show the type and location of the activity in the brain during a seizure. It also is used to evaluate people who are having problems associated with brain function. These problems might include confusion, coma, tumors, long-term difficulties with thinking or memory, or weakening of specific parts of the body (such as weakness associated with a stroke).
  • An EEG is also used to determine brain death. It may be used to prove that someone on life-support equipment has no chance of recovery.
  • Scientists first captured and recorded brain waves in dogs in 1912. By the 1950s the EEG was used commonly throughout the United States.
Medically Reviewed by a Doctor on 12/4/2014

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The eMedicineHealth doctors ask about Electroencephalography (EEG):

Electroencephalography (EEG) - Experience

Describe your experience with an EEG.

EEG - Results

What did your EEG results reveal?

Electroencephalography Definition

A technique for studying the electrical currents within the brain. Electrodes are attached to the scalp. Wires attach these electrodes to a machine, which records the electrical impulses. The results are either printed out or displayed on a computer screen. Different patterns of electrical impulses can denote various forms of epilepsy. Abbreviated EEG.


Read What Your Physician is Reading on Medscape

Normal EEG Variants »

The phrases "electroencephalogram (EEG) variant waves" or "normal EEG variants" refer to waves that are rare or unusual but not generally abnormal.

Read More on Medscape Reference »

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