| BackgroundGlioma is widely considered to be the most common primary malignant tumor of the central nervous system(CNS),representing approximately 40-50%of intracranial tumors,among which the proportion of tumors invading the frontal lobe of the brain is the highest.At present,the etiology of glioma is still unknown,and surgical resection is still an important means of care for patients with glioma.But there was no radical cure and the 5-year survival was poor.The intraoperative protection of cognitive function is a key measure to improve the prognosis and quality of life after surgery for patients with glioma.Therefore,based on the cognitive compensation phenomenon in patients with clinical frontal glioma,it has very important clinical value in exploring the characteristics of brain structural and functional compensation were discussed,and further relealing the correlative mechanism between protection of executive function and structural and functional compensation.And it can also establish a set of objective criteria for patients with frontal glioma to protect their cognitive function during surgery and improve their quality of life.This has been an important subject faced by rehabilitation workers at present,and has become one of the important scientific issues in the field of individualized precise surgical treatment of glioma worldwide.Based on multimodal MRI radiomics signature combined with clinical multi-dimensional cognitive features,this study will investigate the altered pattern characteristics of multidimensional cognitive function,structural and functional reorganization patterns,and the related protection mechanism of cognitive function in patients with unilateral frontal glioma using multimodal neuroimaging techniques(voxel-based morphometric analysis,deterministic fiber tracking technique,regional homogeneity analysis,amplitude of low-frequency fluctuation analysis,degree centrality,structural and functional network connectivity analysis,graph theory analysis).It will provide objective criteria for the development of a set of guidelines for the protection of cognitive function during operation before neurosurgery and improve the quality of life of patients.Part 1:Study on the pattern characteristics of cognitive dysfunction in patients with unilateral frontal gliomaObjective:To explore the abnormal pattern of multimodal cognitive functions in patients with unilateral frontal gliomas(FronG).Methods:From January 2013 and December 2019,total 37 patients with unilateral FronG and40 matched healthy controls(CN)were recruited.All subjects underwent a standardized clinical evaluation,comprehensive multidimensional neuropsychological assessment.Each neuropsychological test was transformed into Z score,and further divided into four cognitive domains(memory function,information processing speed,executive function,and visual-spatial cognitive function).After controlling for the effects of age,education level,and gender,a two-sample independent T-test was used to compare the differences between FronG and CN in the multimodal cognitive domains.One-way analysis of variance(ANOVA)was used to compare the differences in multimodal cognitive domains among left FronG,right FronG,and CN groups,and post-hoc two-sample independent T-test was used to compare the differences in multimodal cognitive domains and tumor volume between left FronG and right FronG.Linear regression was used to analyze the relationships between age,tumor volume,and multi-dimensional cognitive domains.Results:First,compared with the CN,the total FronG group showed significant reduces in memory function,information processing speed,and visual-spatial cognitive function,and the differences were statistically significant(p<0.05),while the differences in executive function were not statistically significant(p>0.05).Memory function,information processing speed,and visual-spatial cognitive function were significantly reduced in the left and right FronG subgroups,and the differences were statistically significant(p<0.05),while the differences in executive function were not statistically significant(p>0.05).Second,there was no significant difference in the multimodal cognitive domains between left FronG and right FronG(p>0.05).Third,the information processing speed in the left and right FronG groups was significantly positively correlated with tumor volume(r=-0.779,p<0.001),but not significantly correlated with age(p>0.05).There was no significant correlation between memory function,executive function,visuo-spatial cognitive function,and age and tumor volume in the left and right FronG groups(p>0.05).Conclusions:Patients with unilateral frontal glioma present deficits in memory function,information processing speed,and visual-spatial cognitive function while present the preserved executive function.And deficitin information processing speed was positively correlated with glioma tumor size.It suggests that there may be a compensatory mechanism in executive function in patients with unilateral frontal glioma,which is independent of tumor size and age.Part 2:Study on the pattern characteristics of structural network reorganization and cognitive protection in patients with unilateral frontal glioma based on DTI characteristicsObjective:To investigate the relationships between rich-club organization,topological organization,and reorganization pattern of structuralnetworks,and itsthe relationships with the protection of cognitive function in patients with unilateral frontal glioma(FronG).And further investigate the differences in these indices relative to patients with temporal lobe gliomas.Methods:From January 2013 to December 2016,total 13 patients with unilateral frontal glioma(FTumor),18 patients with temporal lobe gliomas(TTumor),and 14 matched healthy controls(CN)were recruited.All subjects underwent a standardized clinical evaluation,comprehensive multidimensional neuropsychological assessment,and diffusion tensor imaging(DTI)scan.Graph theory was used to analyze the small-word and rich-club topologies,global and local topological organization properties of DTI white matter structural connectivity network.After controlling for the effects of age,education,and gender,linear regression was used to analyze the relationships between altered rich club,global,and local topological organizational characteristics of DTI white matter structural network and multimodalcognitive domains(memory function,information processing speed,executive function,and visual-spatial cognitive function).Results:First,compared with CN,FTumor group showedlower scores in memory function,information processing speed,and visual-spatial cognitive function,and the differences were statistically significant(p<0.05),but no differences in executive function score(DST)(p>0.05).Second,compared with CN,FTumor group showedl owerfracti onal anisotropy(FA)in the genu of corpus callosum,the right cingulate gyrus,and the right uncinate fasciculus(p<0.05).Third,FTumor group showed lower local network efficiency,while properties and global network efficiency were well preserved.Fourth,the FronG group showed deficits in the nodal shortest path in the left rolandic operculum and degree centrality(DC)of the right dorsolateral and medial superior frontal gyrus.Fifth,the FronG group showed impairment in rich-club organization,and increased structural connectivity among rich-club nodes and reduced structural connectivity among peripheral nodes.Sixth,FTumor showed abnormal in local network efficiency was significantly correlated with information processing speed(r=0.49,p<0.001)while TTumor showed that abnormal in local network efficiency was significantly correlated with memory function(r=0.503,p<0.001).Finally,there were differences in cogntions between FTumor and TTumor(p>0.05).Conclusions:Patients with frontal glioma showed abnormal topological organization properties(i.e.,intact global network properties and altered local network properties),which were associated with impairment in cognitive function.It suggests that there may be a compensatory mechanism in the global network properties in patients with frontal glioma.It can provide a valuable theoretical basis for clinicians to make a comprehensive preoperative plan from the viewpoint of structural connectomics.Part 3:Study on pattern characteristics of functional network reorganization and cognitive protection in patients with unilateral frontal glioma based on sMRI and fMRI featuresObjective:Cognitive control network(CCN)is recognized as a frontal-parietal neural loop and participates in executive function processing.This study aimed to explore the abnormal executive function pattern in patients with unilateral frontal gliomas(FronG),and pattern characteristics of the structural and functional reorganization of CCN,and its relationship with executive function protection.Methods:A total of 37 patients with unilateral frontal glioma(FronG)were recruited in our hospital from January 2013 to December 2019,including 16 patients with left frontal glioma and 21 patients with right frontal glioma,and 40 matched healthy controls(CN).All subj ectsunderwent a standardized clinical evaluation,comprehensivemultidimensional neuropsychological assessment,structural magnetic resonance imaging(sMRI),and functional magnetic resonance imaging(fMRI)scans.Gray matter volume,regional homogeneity(ReHo),amplitude of low frequency fluctuation(ALFF),degree centrality(DC),and functional connectivity in the CCN in CN and FronG were calculated using multimodal neuroimaging technologies.Furthermore,After controlling for the effects of age,gender,and education level,correlation analysis was used to analyze the relationships between altered structural and functional indice and executive function score.Results:Compared with CN group,patients with left frontal glioma showed a decrease in ALFF in dorsal medial prefrontal cortex and an increase in ALFF in right superior parietal cortex within CCN.Patients with left frontal glioma showed an increase in GM volume and ALFF in the left superior parietal cortex within CCN network.In addition,patients showed an increase in functional connectivity between the left superior parietal cortex and the dorsal medial prefrontal cortex and the right superior parietal cortex within CCN.In particular,increased ALFF in the left superior parietal cortex withinCCN network was significantly positively correlated with executive function scores(r=0.690,p=0.009).There was no significant difference in ReHo and DC between the two groups(p>0.05).Conclusions:In patients with unilateral frontal glioma,tumor invasion of the frontal lobe induced contralesional structural and functional reorganization in the posterior CCN network.It is suggested thatthe contralesionalsuperior parietal cortex may be a functional compensation hub within the CCN network.This compensation hub may protect it against the detrimental effects of tumor invasion on executive functions. |
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