Definition: An EEG (electroencephalogram) is a test that records the electrical activity in the brain. Brain cells create tiny electrical impulses for communicating with each other. The EEG picks up these impulses through tiny wires (electrodes) placed on your scalp. The impulses are amplified and digitally recorded by a computer. The recordings look like wavy lines (sometimes called brain waves). An EEG may be done when you are awake, asleep, or both.
An EEG is usually done to see if a person is having seizures, and if so, what type of seizures they are. The EEG can also look for changes in brain activity caused by head injury, tumor, infection, or other problems that affect the brain. In addition, an EEG may be used to evaluate brain activity in someone who is unconscious or in a coma.
Also Known As: electroencephalogram, brain waves
