A Research Of Brain Network In Temporal Lobe Epilepsy Based On FMRI

Temporal lobe epilepsy(TLE)is a common type of focal epilepsy,which refers to the seizure originating from the temporal lobe,which is common in adults and adolescents.In TLE patients,sudden loss of consciousness significantly worsens the quality of life and increases the risk of death.Although previous studies have begun to study the pathological mechanism of epilepsy at different scales,the pathogenesis of epilepsy is still not well understood,especially the brain mechanism is still not clear.In recent years,with the development of neuroimaging technology and brain network analysis methods,especially the rapid development of resting-state functional magnetic resonance imaging(f MRI),there have been many studies on the pathological mechanism of temporal lobe epilepsy at different scales.In this paper,from the static and dynamic perspectives,combined with functional connectivity,functional connectivity density analysis method and dynamic thought,aiming at the consciousness dysfunction of temporal lobe epilepsy,the brain network mechanism of temporal lobe epilepsy was studied.The main research contents included the following two aspects.1.First,from a static point of view,the thalamic subnuclear connectivity pattern with consciously impaired temporal lobe epilepsy was studied.The thalamus,as a key node in the transmission of neural information,is composed of multiple nuclei,many of which are involved in temporal lobe epilepsy(TLE)seizures(focal onset associated with impaired consciousness).To investigate the unknown changes in functional projections between different thalamic subnuclei and subcortical-cortical systems in temporal lobe epilepsy(TLE),we investigated the functional connections(FC)of the thalamic subnucleus in 26 TLE patients with impaired consciousness and 30 healthy controls matched for sex,age,and education.The results showed that the FC of TLE differed significantly between different thalamic nuclei and subcortical networks compared with healthy controls.The connections between the anterior thalamic nucleus and hippocampus pathways as well as the anterior cingulate tended to decrease abnormally,but increased in the dorsolateral prefrontal lobe.The abnormal connections in the posterior medial ventral nucleus were concentrated in the sensorimotor region,and the significant abnormal connections in the lateral central nucleus were concentrated in the parhippocampal and brainstem regions.FC reduction between the anterior thalamic nucleus and hippocampus pathways was significantly positively correlated with TLE memory performance,while other abnormal connections were not significantly correlated with memory scores in patients with temporal lobe epilepsy.Based on the above analysis,we demonstrate that there is a specific pattern of functional connectivity in multiple thalamocortical circuits,and that there is an abnormal decrease trend in patients compared to normal subjects.Our findings suggest that there is a degree of thalamocortical circuit damage in patients with temporal lobe epilepsy,and this damage may be associated with abnormal behavior and impaired memory function.This finding may provide a basis for improved therapies that directly target different thalamocortical circuits.2.Brain activity has the character of instantaneous changes,and epilepsy is a kind of typical instantaneity and dynamic neural pathological activity,by adopting the idea of dynamic brain network can fully describe the dynamic process of epilepsy,further,this article uses the dynamic function connection density analysis method based on sliding window,through the whole brain function connection mode is divided into inside hemisphere and connection between hemispheres,explore the hemisphere of temporal lobe epilepsy patients within and between the hemispheres dynamic function integration.First of all,based on the sliding window method,over a period of magnetic resonance signal is divided into a number of different pieces,respectively in each time window to calculate the whole brain function connection density distribution,and according to some one and the relative position of whole brain other voxel,connect the function of the whole brain is divided into ipsilateral and contralateral connections,namely interhemispheric connection and connection between hemispheres,and then we use the standard deviation as a measure of variability in each hemisphere of subjects and pattern distribution between the hemispheres.The statistical results showed that,compared with the healthy controls,the dynamic functional connectivity density in the anterior cingulate cortex/medial prefrontal cortex increased both intrahemispheric and interhemispheric,and the dynamic connectivity density in the fusiform gyrus/parahippocampal gyrus decreased in patients with temporal lobe epilepsy.In addition,temporal lobe epilepsy patients also showed increased dynamic density of interhemispheric dynamic functional connections.In further correlation analysis with clinical manifestations,we found that the abnormal temporal dynamics of ipsilateral dynamic functional connection density in patients with temporal lobe epilepsy was related to seizure frequency.This study dynamically confirms the abnormal intrahemispheric and interhemispheric functional integration in patients with temporal lobe epilepsy,and highlights the potential role of abnormal intrahemispheric dynamic functional integration in disease dimensions in patients with temporal lobe epilepsy.In summary,using f MRI and brain network analysis method,this paper explored the abnormality of brain network in temporal lobe epilepsy from the static and dynamic perspectives.These findings can help us to fully understand the physiological and pathological mechanisms of temporal lobe epilepsy patients,provide imaging data for clinical diagnosis and treatment of temporal lobe epilepsy,and have important guiding significance for the exploration of potential biological markers.