Jiajie Mo1,2,3, Baotian Zhao1,2,3, Sophie Adler4, Jianguo Zhang1,2,3, Xiaoqiu Shao3,5, Yanshan Ma6, Lin Sang6, Wenhan Hu1,2,3, Chao Zhang1,2,3, Yao Wang1,2,3, Xiu Wang1,2,3, Chang Liu1,2,3, Kai Zhang1,2,3. 1. Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China. 2. Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China. 3. China National Clinical Research Center for Neurological Diseases, Beijing, China. 4. Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, University College London, London, UK. 5. Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China. 6. Department of Neurosurgery, Beijing Fengtai Hospital, Beijing, China.
Abstract
BACKGROUND: Magnetic resonance imaging (MRI) changes in hippocampal sclerosis (HS) could be subtle in a significant proportion of mesial temporal lobe epilepsy (mTLE) patients. In this study, we aimed to document the structural and functional changes in the hippocampus and amygdala seen in HS patients. METHODS: Quantitative features of the hippocampus and amygdala were extracted from structural MRI data in 66 mTLE patients and 28 controls. Structural covariance analysis was undertaken using volumetric data from the amygdala and hippocampus. Functional connectivity (FC) measured using resting intracranial electroencephalography (EEG) was analyzed in 22 HS patients and 16 non-HS disease controls. RESULTS: Hippocampal atrophy was present in both MRI-positive and MRI-negative HS groups (Mann-Whitney U: 7.61, P<0.01; Mann-Whitney U: 6.51, P<0.01). Amygdala volumes were decreased in the patient group (Mann-Whitney U: 2.92, P<0.05), especially in MRI-negative HS patients (Mann-Whitney U: 2.75, P<0.05). The structural covariance analysis showed the normalized volumes of the amygdala and hippocampus were tightly coupled in both controls and HS patients (ρSpearman =0.72, P<0.01). FC analysis indicated that HS patients had significantly increased connectivity (Student's t: 2.58, P=0.03) within the hippocampus but decreased connectivity between the hippocampus and amygdala (Student's t: 3.33, P=0.01), particularly for MRI-negative HS patients. CONCLUSIONS: Quantitative structural changes, including hippocampal atrophy and temporal pole blurring, are present in both MRI-positive and MRI-negative HS patients, suggesting the potential usefulness of incorporating quantitative analyses into clinical practice. HS is characterized by increased intra-hippocampal EEG synchronization and decreased coupling between the hippocampus and amygdala. 2021 Quantitative Imaging in Medicine and Surgery. All rights reserved.
BACKGROUND: Magnetic resonance imaging (MRI) changes in hippocampal sclerosis (HS) could be subtle in a significant proportion of mesial temporal lobe epilepsy (mTLE) patients. In this study, we aimed to document the structural and functional changes in the hippocampus and amygdala seen in HS patients. METHODS: Quantitative features of the hippocampus and amygdala were extracted from structural MRI data in 66 mTLE patients and 28 controls. Structural covariance analysis was undertaken using volumetric data from the amygdala and hippocampus. Functional connectivity (FC) measured using resting intracranial electroencephalography (EEG) was analyzed in 22 HS patients and 16 non-HS disease controls. RESULTS: Hippocampal atrophy was present in both MRI-positive and MRI-negative HS groups (Mann-Whitney U: 7.61, P<0.01; Mann-Whitney U: 6.51, P<0.01). Amygdala volumes were decreased in the patient group (Mann-Whitney U: 2.92, P<0.05), especially in MRI-negative HS patients (Mann-Whitney U: 2.75, P<0.05). The structural covariance analysis showed the normalized volumes of the amygdala and hippocampus were tightly coupled in both controls and HS patients (ρSpearman =0.72, P<0.01). FC analysis indicated that HS patients had significantly increased connectivity (Student's t: 2.58, P=0.03) within the hippocampus but decreased connectivity between the hippocampus and amygdala (Student's t: 3.33, P=0.01), particularly for MRI-negative HS patients. CONCLUSIONS: Quantitative structural changes, including hippocampal atrophy and temporal pole blurring, are present in both MRI-positive and MRI-negative HS patients, suggesting the potential usefulness of incorporating quantitative analyses into clinical practice. HS is characterized by increased intra-hippocampal EEG synchronization and decreased coupling between the hippocampus and amygdala. 2021 Quantitative Imaging in Medicine and Surgery. All rights reserved.
Authors: Juan Eugenio Iglesias; Jean C Augustinack; Khoa Nguyen; Christopher M Player; Allison Player; Michelle Wright; Nicole Roy; Matthew P Frosch; Ann C McKee; Lawrence L Wald; Bruce Fischl; Koen Van Leemput Journal: Neuroimage Date: 2015-04-29 Impact factor: 6.556
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