Research On Brain Functional Reorganization Of Patients With Temporal Lobe Tumor Based On Anatomical Brain Network

Temporal lobe corresponds to the primary auditory cortex,patients with temporal lobe tumors usually show cognitive impairments in language,hearing and memory.Studies have shown that peripheral nerve injury caused by brain tumors can lead to immediate or long-term brain function compensation and remodeling,which may result from the plasticity of the brain.Preoperative compensation and remodeling of brain function will influence the therapeutic effect of brain tumor resection,therefore,it is essential to explore the functional and structural reorganization of patients’ brain before surgery.For many researches in studying functional characteristics of the brain,traditional literature paid more attention on analyzing functional changes and possible remodeling of brain from a single aspect,structure or function,which lacks the interrelationship analysis between brain function and structure.This study aimed at analyzing the topological characteristics and the influence of tumor lesions on the brain structural network on the basis of DTI.Combining with resting-state fMRI,this study also explored the association between brain structure and function,the influences on brain function occurring in response to alterations in brain structure,as well as the reorganization of brain function.The main contents and innovations of the paper are listed as follows:1.Research on global characteristics of the brain based on diffusion tensor imaging.The brain structural network of both healthy volunteers and patients with temporal lobe tumor were constructed respectively.Based on the global and local topological parameters of whole brain structural network,the abnormal changes of brain structure were analyzed.The results showed that local parameters of patients were changed a lot and there was only significant decrease in global parameters of global efficiency.The analysis results indicated that tumor lesions only caused regional changes of brain and the functional impairment in whole brain was not significant,which may probably because of compensation mechanism resulting from structural plasticity and functional reorganization of the brain.2.Study on fiber bundles remodeling mechanism based on structural sub-network analysis.The whole brain structural network was divided into three different sub networks based on the length of fiber bundle tracking by deterministic fiber tracking algorithm.The influence of tumor lesions on the sub networks were detected by analyzing the global characteristic parameters of each sub network.The results showed that the temporal lobe tumor led to the increase in global efficiency of short-distance sub-networks,indicating the regeneration of fiber bundles in the local brain regions,while the fiber bundles between the long-distance brain areas remained unchanged,indicating that the brain structure remodeling occurred in the local areas of the brain.3.Researches on the connectivity between core brain regions.This part of study was aimed to find the connection between important brain regions and analyze the reorganization of information transmission channels.Combined DTI with fMRI analysis techniques,based on the connectivity analysis between core nodes,the changes of information transmission channels in brain of tumor patients were studied from the aspects of functional,structural and effective connections between core nodes of the brain.The result showed that the changes of the core nodes verify the compensatory of the brain,besides,compared with normal subjects,the changes of information flow among important nodes changed significantly in patients with temporal lobe tumor.The study of information-driven between the core nodes showed that,compared with healthy controls,the ability of information-driven from visual cognition to scenario memory then to mood swings in patients was enhanced.4.Study on interrelationship between brain function and structure based on functional module network analysis and fMRI imaging technique.ICA method was utilized to divide the whole brain into six different functional modules,combining with the analysis result of functional module network based on DTI data,the structural characteristics and functional connections in different brain functional modules were further explored.Based on this,the impact of tumor on brain function,as well as the possible compensatory mechanism of brain in patients,was analyzed.The result showed that compensatory existed in patients’ brain and the frontal lobe may participate in the restoration of brain functions based on compensatory mechanism.