Disclosed herein is a multiple electrode, closed-loop system for the treatment of certain neurological disorders such as epilepsy, migraine headaches and Parkinson's disease. Specifically, the present invention combines a multi-electrode array with sophisticated signal processing techniques to achieve reliable detection of the onset of a neurological event (such as an epileptic seizure or migraine headache) typically originating from a focus of limited spatial extent within the brain. It is highly desirable to detect an epileptic seizure at least 5 seconds before the onset of clinical symptoms. Since there is often a d-c shift in the EEG voltage more than 5 seconds before the seizure, disclosed herein is a means for utilizing the d-c shift of the EEG for early detection of the seizure.