Combined Structural And Functional MRI Studies Of Working Memory In Epilepsy With Medial Temporal Lobe Epilepsy

Epilepsy is a common neurological disorder, and its electrophysiology characteristic isabnormally high excitability and synchronization of the neural activity. The long term seizure hascaused the damage of cognitive function in TLE patients. This study focuses on medial temporal lobeepilepsy with hippocampal sclerosis, which is characterized by the epileptiogenic focus andneuropathological changes in the pathologic substrate of hippocampal sclerosis. Hippocampus palysan important role in short term memory. However little is known about the connectivity betweenhippocampal structures and adjacent brain regions. So it’s significant to investigate the functional andstructural connectivity in mTLE using the techniques of functional magnetic resonance imaging anddiffusion tensor imaging.The main contents and innovations of this thesis are as follows:1. This study mainly explores the presence of impairment of working memory in left medialtemporal lobe epilepsy with hippocampal sclerosis using functional magnetic resonance imagingthrough2-back task programming. And mTLE patients presented negative activation in the DLPFC,thalamus, bilateral frontal lobe, basal ganglia and hippocampus compared to healthy controls. Regionsof positive activation contained partial regions of DMN, such as precuneus and posterior cingulatedcortex. This result reflects impairment of advanced cognitive abilities to some extent, and probablysuggests the physiopathologic mechanism of mTLE relevant to working memory.2. We choose three pairs of ROIs related to working memory from the result of BOLD-fMRI data.After we registrate those ROI from MNI space to individual space and then analyze the data. Wefound the number of fiber bundle has reduced among these ROIs, such as left hippocampus and righthippocampus、left hippocampus and left thalamus、left hippocampus and left frontal lobe and so on.And the number of fiber bundle has increased among these ROIs, such as left thalamus and rightthalamus, right hippocampus and right thalamus. And the FA value in some regions related to lefthippocampus in the term of fiber bundles such as right hippocampus、right thalamus has beendecreased.