Brain Structure And Function Of Adult Temporal Lobe Epilepsy With Negative MRI Based On Multimodal Magnetic Resonance Imaging

Objective: MRI negative temporal lobe epilepsy(TLE-N)patients are an important subgroup of temporal lobe epilepsy(TLE),showing typical electroclinical physiological manifestations of temporal lobe epilepsy,while no eclamptic lesions can be seen by the naked eye in conventional structural MRI.(1)Through Voxel-Based Morphometry(VBM)and Surface-Based Morphometry(SBM),the structural changes of gray matter in patients with MRI negative c TLE(c TLE-N)and MRI negative r TLE(r TLE-N)were analyzed.(2)Various rs-f MRI analyses,such as ALFF,f ALFF,Re Ho,and region-based FC analysis,were used to comprehensively investigate spontaneous brain activity,synchronous brain activity,and functional connectivity in MRI-negative TLE patients.(3)Multivariate pattern analysis method based on machine learning was applied to classify and detect TLE patients with negative MRI by using structural image index(GMV)and three functional indicators of rs-f MRI(ALFF,f ALFF,Re Ho).Methods:(1)VBM and SBM tools were used to compare the morphological differences in gray matter of the subjects,and to analyze the correlation between morphological characteristics of abnormal brain areas and clinical variables.(2)In order to comprehensively assess the brain function changes associated with TLE-N patients,three voxel-based functional indicators(ALFF,f ALFF,Re Ho)were used and functional connectivity(FC)analysis was performed based on whole brain regions.(3)PRo NTo software was used to analyze the diagnostic efficacy of voxel-based GMV,ALFF,f ALFF and Re Ho for TLE-N patients.Results:(1)VBM analysis results: Compared with the HC group,patients in c TLE-N group mainly showed increased gray matter volume in the right inferior temporal gyrus,fusiform gyrus,parahippocampal gyrus,hippocampus,infroccipital gyrus and left lingual gyrus,while no obvious gray matter volume reduction area was observed(after FDR correction,P<0.05).Compared with HC group,patients in r TLE-N group showed increased gray matter volume in the triangle region of inferior frontal gyrus,right inferior temporal gyrus,middle temporal gyrus,polar-temporal middle gyrus,superior temporal polar-temporal gyrus,superior temporal gyrus,hippocampus,lentiform nucleus,middle occipital gyrus,peritalobiate cortex,insula,anterior cuneus,supraoccipital gyrus,superior parietal gyrus,inferior parietal corner gyrus,parietal gyrus,and superior frontal gyrus.The gray matter volume decreased in the left orbital superior frontal gyrus and orbital middle frontal gyrus(after FDR correction,P<0.05).There was a weak correlation between the gray matter volume in the right supplementary exercise area and age of onset in c TLE-N group(r=-0.310,P=0.018).The volume of gray matter in the left olfactorial cortex(r=-0.455,P=0.038)and the right superior marginal gyrus(r=-0.482,P=0.027)in the r TLE-N group had a moderate negative correlation with Mo CA score.SBM analysis results: Compared with the control group,there was no obvious cortical thickness change in the negative MRI group.In the MRI-negative r TLE group,local cortical thickness was thinner in the left inferior temporal gyrus,lateral orbitofrontal gyrus,superior parietal gyrus,right temporal pole,upper anterior cingulate gyrus and insular gyrus(FWE correction,P<0.05).There was no significant correlation between the abnormal cortical thickness and clinical indicators between the c TLE-N group and the r TLE-N group.(2)There were certain differences in the analysis of ALFF and f ALFF.Compared with the HC group,the ALFF value of the left cerebellum and the left superior temporal polar gyrus and the f ALFF value of the right middle frontal gyrus were decreased in patients with MRI-negative c TLE.r TLE patients with negative MRI showed lower ALFF values in the right middle temporal gyrus and f ALFF values in the right inferior temporal gyrus,right rectus muscle,right suprapital gyrus and left inferior parietal angular gyrus than the control group.ALFF values increased in left lingual gyrus,right precuneus,left anterior central gyrus and left paracentral lobule,and f ALFF values increased in left fusiform gyrus,left thalamus,left superior temporal gyrus,left middle frontal gyrus and left posterior central gyrus.Compared with ALFF and f ALFF,Re Ho analysis showed more extensive distribution of abnormal brain regions,and also showed more changes in Re Ho value.MRI-negative c TLE patients were distributed in the left orbital inferior frontal gyrus,right middle temporal gyrus,right precuneus,and left pericalis talaris.The patients with r TLE-N were distributed in the left ilerectus muscle,left inferior orbitofrontal gyrus,left anterior central gyrus,right superior temporal gyrus,bilateral middle occipital gyrus,bilateral peritalar fissure cortex,and bilateral thalamus.When functional connectivity(FC)analysis was performed based on the whole brain area,functional connectivity was both enhanced and weakened in MRI-negative c TLE patients compared with the HC group,while functional connectivity was generally weakened in MRI-negative r TLE patients.Both groups of patients had abnormal connection function mainly in the limbic system,and a large number of MRI-negative r TLE patients had weakened connection function in the limbic temporal lobe system.The right posterior cingulate gyrus/left temporal pole middle temporal gyrus connection was enhanced in MRI-negative c TLE patients,while the right posterior cingulate gyrus/left paracentral lobule,left posterior cingulate gyrus with bilateral paracentral lobule and left precuneus were weakened in MRI-negative r TLE patients.(3)In the two groups of classification,the accuracy of GMV index as classification standard was 92.13%,and the AUC value was 0.96;the accuracy of ALFF index as classification standard was 94.49%,and the AUC value was 0.96;The accuracy of f ALFF index was 91.34%,and the AUC value was 0.92.The accuracy of Re Ho index was 94.49%,and the AUC value was 0.97(P=0.001).Based on the four structural and functional indicators,the brain regions with the largest difference between the negative MRI TLE patients and the control group were mainly concentrated in the right precuneus,left parietal inferior angular gyrus,and left parietal lobule.Conclusion: In this study,s MRI and rs-f MRI techniques were used to structurally and visually study the comprehensive changes of MRI negative TLE patients from the perspective of gray matter structure,local brain activity energy,and the correlation between structure and function.Moreover,based on the whole brain level,the classification study was conducted from the perspective of structure and function combined with the machine learning classification method,and biological markers based on the whole brain image data were found.TLE patients and normal people with negative MRI were selected from the individual level area.