How does the eeg test work?

Brain activity: In the same way an ekg measures electrical activity from the heart, an EEG measures activity from the brain. Electrodes are placed on the scalp and the patient lies quietly while brainwaves are recorded. Sometimes, hyperventilation and/or flashing lights are used to evoke different responses. It is important to relax, as electrical activity from muscle can swamp the signals from the brain.

Records brain: Electrical activity occurs thruout the body, and like an electrocardiogram recording heart activity, small discs are taped to specific areas of the scalp, and pickup underlying electrical impulses from brain activity. The rhythms vary during sleep and waking, and are compared to normal expectations. Diffuse slowing may correlate with diffuse problems, and paroxysmal activity may indicate seizure.