Analysis of frequency domain of EEG signals in clinical location of epileptic focus.

As a suddenly abnormal discharge of brain neurons, epilepsy can lead to encephalographic (EEG) abnormalities. Data of 3 epileptic patients recorded by depth intracranial electrodes are analyzed with time-frequency algorithms to observe the abnormal changes in different frequency ranges. Comparing the frequency domain of the normal and epileptic signals that contain several periods of clinical seizures and intervals, a remarkable range of high frequency is identified and corresponds to the seizure. According to the corresponding position of those channels that produced abnormal signals, the epileptic focus is determined theoretically and verified by comparison with the clinical diagnosis and surgical results. Furthermore, the order of the presence of different frequency ranges is listed. The finding proposed in this study could be a fresh method to improve the diagnosis of epilepsy.