Study Of Epileptic Onset Localization Based On IEEG-MRI Multi-modality

Epilepsy is a chronic disease of brain dysfunction,which is caused by abnormal discharge of brain neurons.Almost 80% patients could be cured by medicine.However,there are 20% patients need to be treated by surgery.As clinical operation on this disease needs to look for its epilepsy focal zone and remove it,the study on the epilepsy focal zone localization is essential.The traditional ways to locate the focal zone are electroencephalogram(EEG)orIntracranial electroencephalography(iEEG).However,with the development of the medical imaging,the modern way to analyze epilepsy focal zone is co-analysis its multi-modality.Therefore,this essay will focus on the research of multi-modality in epileptic onset localization.This research is based on the clinical observations of epilepsy patients' Computed Tomography(CT),Magnetic Resonance Imaging(MRI),iEEG,and Diffusion Tensor Imaging(DTI)etc.,and it discusses the three steps in epileptic onset localization: Firstly,locating the electrodes in the brain via the registration of the pre-operation MRI and the post-operation CT.Secondly,analyzing the multi-channel iEEG via Granger Causality,PSI,and Transfer Entropy in order to locates the focal zone,and providing the capable conditions in these three algorithms and their time length.Thirdly,verifying the focal zone by comparing DTI data of epilepsy patients and normal people;creating the brain network of structure based on its fractional anisotropy,fiber number and volume;and finally analyzing the brain network matrix.Granger Causality,used to locate focal zone using multi-channel iEEG into epilepsy within 4 seconds,cannot perform accurately,and the analysis results indicates false positive,which proves Granger Causality requires the stability of signal.PSI,on the other hand,used to locate focal zone within one minute,and it considers analyzing the iEEG data before seizures is beneficial for epileptic onset localization.As the sensibility of signal,it took Transfer Entropy within one second to locate the focal zone correctly.In the field of the brain network structure creation,this essay focuses on the characteristic of the small world,and verifies the location of the focal zone via betweencentrality analysis.Therefore,this essay provides effective support in the fields of iEEG and DTI,and it also provides relevant reference for the clinical epileptic onset localization.