Brain Morphology And Brain Connection Network Study Of Children With Hippocampal Cirrhosis Medial Temporal Lobe Epilepsy Based On Structural Magnetic Resonance

Objective: Mesial temporal lobe epilepsy(MTLE)is a common type of intractable epilepsy,and hippocampal sclerosis(HS)has been considered as the most frequent pathogenesis of MTLE.The long-term duration of HS may cause severe brain structural deficits to patients with mesial temporal lobe epilepsy with hippocampal sclerosis(MTLE-HS),exert a heavy burden to their brain development,and even cause disturbed memory function and visual orientation.Thus,it is important to explore the brain structural alternations of MTLE-HS.Methods: We recruited 13 patients with left mesial temporal lobe with hippocampal sclerosis(LMTLE-HS),6 patients with right mesial temporal lobe with hippocampal sclerosis(RMTLE-HS)and 20 age-,gender-matched healthy controls.All the MRI acquisitions were performed on 3.0T MRI scanner with T1 weighted three dimensional magnetization prepared rapid acquisition gradient echo sequence.By using the voxel-based morphology(VBM)method,we calculated the gray matter volume of LMTLE-HS/RMTLE-HS and controls,and studied the differences of gray matter volume between these two subtypes and the controls.By using the surface-based morphology(SBM)method,we calculated the cortical thickness of LMTLE-HS/RMTLE-HS and controls,and studied the differences of cortical thickness between these two subtypes and the controls.Based on the cortical thickness of each subjects,we applied the graph-based theory to construct the brain connectivity network of LMTLE-HS/RMTLE-HS,and studied the differences of network topology between these two subtypes and the controls.Results: Significant GMV increase were found in left parahippocampal gyrus,amygdala,middle/superior temporal gyrus,bilateral cerebellum,and GMV decrease were seen in ipisilateral postcentral gyrus.The RMTLE-HS group showed GMV increase in ipisilateral parahippocampal gyrus,middle frontal gyrus and inferior parietal gyrus;and GMV decrease in contralateral frontal lobe,precentral,superior occipital lobe.In LMTLE-HS subgroup,cortical thickness decreased in ipisilateral caudalmiddlefrontal gyrus,increased in contralateral inferiortemporal gyrus.In RMTLE-HS,cortical thickness decreased in the ipsilateral superior,inferior parietal gyrus,anterior parietal lobe,posterior frontal lobe,lateraloccipital gryus,contralateral lateraloccipital gryus,middlefrontal gyrus,superiorfrontal gyrus,and pericalcarine.Both LMTLE-HS and RMTLE-HS had displayed disturbed small worldness,network properties and network robustness,such as lower clustering coefficient,longer path length,worse global and local efficiency,and weaker network robustness in random or target edge and node attack.Conclusion: In summary,MTLE-HS showed abnormal morphology,and disrupted network topological properties.In addition,the LMTLE-HS and RMTLE-HS showed distinctive patters of morphological and topological changes.This study may reveal the internal structural alternations of MTLE-HS from the morphological and network level,and may provide important information for understanding the underlying pathological mechanism of MTLE-HS.