Electroencephalography (EEG) may be used to help diagnose conditions, such as epilepsy, that are associated with abnormal electrical activity in the brain. Electrodes are attached to a person’s scalp, and recordings are made of brain activity with the eyes open and closed. A strobe light may be switched on for short periods to see if brain activity changes. The procedure takes approximately 20–30 minutes and is painless.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.