Research of EEG from patients with temporal lobe epilepsy on causal analysis of directional transfer functions

Abstract

Objective: 16-channel EEG data during intermittent episodes of epilepsy is recoded and analyzed to find lesions source and relationship between brain areas for temporal lobe epilepsy (TLE) patients by causal analysis method. Methods: There are 8 patients with temporal lobe epilepsy, 5 males and 3 females, aged between 19 to 47 years, the average age of 30.63 years. 16-channel EEG in 8 patients was recorded by Stellate Video EEG. Sample time = 20s (sample points = 4000), Sampling frequency fs = 2 0 0 H z. Directional transfer functions is used to direct the information transduction between each channel of the EEG signals, which can reflect the causal relationship between each channel and determine the location of the lesions source. (In this paper, we used eConnectome software that developed by Biomedical Functional Imaging and Neuroengineering Laboratory at the University of Minnesota, directed by Dr. Bin He). Results: Causality results of 8 patients during intermittent episodes of EEG 20s are as follows: 6 patients' lesions source are located on channels T5 and F7 in left tempora, One of 5 cases' are located on channel T5 in the left posterior temporal, One of 1 case is located on channel F7 in the left anterior temporal. And 2 patients' lesions source are located on channels T4 and T6 in the right tempora, in the 2 patients, 1 case's lesions source is located on channel T4 in right middle temporal, 1 case's lesions source is located on channel T6 in right posterior temporal. Causality results consistent with the clinical diagnosis. Conclusions: Research of EEG on causal analysis of directional transfer function can effectively determine the lesions source of seizure, and effectively calculate the transmission direction of the multi-channel information, which is to provide support in the clinic for determine the source of seizure. © 2011 Springer-Verlag.