Research On Localization Of Epileptic Foci And Epileptic Networks With Simultaneous EEG-fMRI Examination Technique

Objective:The study of Simultaneous EEG and functional magnetic resonance imaging(EEG-fMRI)in generalized epilepsy to research epileptic network and in partial epilepsy to locate epileptic foci.To explore the application value of this technology in epileptic mechanism and localization diagnosis.Methods:16 cases of epilepsy were recruited in the present study from April 2013 to April 2014,including nine patients with generalized epilepsy,7 patients with partial epilepsy.All patients imaging was normal,and had clear and frequent epileptic EEG discharges.In this study,all patients were examined by 3.0T MRI scan(T1 W1、T2WI、T2FLAIR),RS-fMRI(ReHo、ALFF、fALFF)and EEG-fMRI scans of the head,in order to analyse BOLD signal change regulation associated with epileptic discharge in generalized and partial epilepsy.Results:1.There are nine cases of generalized epilepsy patients,six patients had effective EEG-fMRI data,EEG showed 2-5Hz synchronization(multiple)spike and slow wave discharges,EEG-fMRI showed the interictal activation signal in five cases:four cases of bilateral frontal cortex activation,five cases of bilateral parietal cortex,three cases of medial frontal cortex,three cases of temporal lobe,two cases of occipital lobe,two cases of thalamus,two cases of caudate nucleus,two cases of cerebellum.Activation signal mainly in the cortex,frontal and parietal cortex was significantly;some accompanied by thalamic activation;the results were bilateral asymmetry and the left activate obvious.We captured four times of absence seizures,signal activation had two types,one is a thalamic activation with/without frontal cortical activation,another is frontal cortical and subcortical activation.2.There are seven cases of partial epilepsy patients and had effective EEG-fMRI data.Seven patients’ BOLD signal activation area were concordant with epileptic discharge area.From the lobe,BOLD signal activation area were fully concordant with epileptic discharge area in three patients;BOLD signal activation area were in epileptic discharge area and adjacent areas,that is to say,the main partially concordant in three patients;BOLD signal activation area were discordant with epileptic discharge area in one case.Conclusion:1.Generalized epilepsy:BOLD signal activation often throughout the bilateral cortical or subcortical,many accompanied by bilateral thalamic activation.Absence seizures may have different epileptic network,epileptic discharge may originate in the frontal cortex or thalamus,spread pathway may be cortex-thalamus-the cortex,cortical-subcortical or thalamus-cortical loops.In interictal period,BOLD signal showed asymmetry,often frontal and parietal cortex activation and the left predominantly.Basal ganglia,temporal lobe,cerebellum,occipital and other structures are also involved in the activation BOLD signal.2.Partial epilepsy:BOLD signal is activated mainly in patients with epileptic discharge or adjacent areas.In more distant regions activated BOLD signal is weak.This helps to study transmission of epileptic discharges.BOLD activation signal and EEG epileptic discharge has a good correspondence,EEG-fMRI can be used as preoperative examination methods in partial epilepsy epileptic foci location.