Also known as a Brain Wave Test.
An EEG records the minute electrical impulses produced by the activity
of the brain.
The EEG is used to evaluate sleep disorders and to
determine the causes of periods of unconsciousness.
An EEG is also used to diagnose seizure disorders, confusion, brain
tumors, head injuries, degenerative diseases, and metabolic or chemical
disturbances that affect the brain.
The test is performed while the patient is lying down.
The technician places a number of small electrodes on the scalp
over different regions of the brain.
The electrodes carry information about the brain's electrical activity
to an amplifier.
A special machine records the amplified brain waves and produces
a pattern of tracings called an electroencephalogram.
The procedure is painless, produces no side effects,
& takes about 45 minutes.
Recordings are taken with the patient at rest, with eyes open &
then shut, during & after hyperventilation, & while looking
at a flashing light.