Electroencephalogram

A study of electrical current 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.

Electroencephalogram is abbreviated EEG.

Different patterns of electrical impulses can denote various problems within the brain including different forms of epilepsy.

Most EEGs see only a moment in time within the brain, and can catch only gross abnormalities in function.

An overnight EEG is designed to check the electrical activity in the brain of a sleep-deprived patient, increasing the chance that seizure activity will be revealed.

Also available are 24- or 48-hour EEGs, which measure electrical activity over one or two days, usually using mobile EEG units.