EEG and Evoked Potentials monitor the electrical activity of the brain using small electrodes attached to the scalp. An EEG is one of the main diagnostic tests for epilepsy, it can also be utilized in diagnosing other neurological disorders. Similarly evoked potentials measure the electrical activity in certain parts of the brain caused by light and sound, and is used to help diagnose MS or related disorders. Each test takes about an hour to complete and is performed by a technician in the office, the results are reviewed and interpreted by the ordering physician.