Alterations of the intrinsic amygdala‐hippocampal network in juvenile myoclonic epilepsy

Abstract

Introduction: Several lines of evidence suggest that the amygdala-hippocampus is involved in the epileptogenic network of juvenile myoclonic epilepsy (JME). The aim of this study was to investigate the alterations in the individual nuclei of the amygdala and hippocampal subfields, and the intrinsic amygdala-hippocampal network of patients with JME compared to healthy controls.Methods: This retrospective study conducted at a single tertiary hospital involved 35 patients with newly diagnosed JME, and 34 healthy subjects. We calculated the individual structural volumes of 18 nuclei in the amygdala, and 38 hippocampal subfields using three-dimensional volumetric T1-weighted imaging and FreeSurfer program. We also performed an analysis of the intrinsic amygdala-hippocampal global and local network based on these volumes using a graph theory and Brain Analysis using Graph Theory (BRAPH) program. We investigated the differences in these volumes and network measures between patients with JME and healthy controls.Results: There were no significant volume differences in the nuclei of the amygdala and hippocampal subfields between patients with JME and healthy controls. However, we found significant differences in the global network between patients with JME and healthy controls. The mean clustering coefficient was significantly decreased in patients with JME compared to healthy controls (0.473 vs. 0.653, p = .047). In addition, specific regions in the hippocampal subfields showed significant differences in the local network between the two groups. The betweenness centrality of the right CA1-head, right hippocampus-amygdala-transition area, left hippocampal fissure, left fimbria, and left CA3-head, was increased in patients with JME compared to healthy controls. Conclusion:The intrinsic amygdala-hippocampal global and local networks differed in patients with JME compared to healthy controls, which may be related to the pathogenesis of JME, and memory dysfunction in patients with JME.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Altered Cerebellar Volumes and Intrinsic Cerebellar Network in Juvenile Myoclonic Epilepsy

“…Genetically determined dysfunctions of crucial cognitive systems, such as visuomotor coordination and linguistic communication, have emerged as key mechanisms of seizure genesis in JME, which suggests a new paradigm to consider JME as a system disorder [38]. However, some researchers have suggested that JME may be a network disorder, as it is associated with abnormalities in multiple brain regions and neural networks [7][8][9]. Our study also supported the concept of JME as a network disease.…”

“…A study using structural covariance network and graph theory reported disrupted topological organization of the global brain network and hub reorganization in patients with newly diagnosed JME and in a drug-naïve state [7]. Furthermore, the intrinsic thalamic [8] and intrinsic amygdala-hippocampal networks [9] have been suggested to show alterations in patients with JME when compared with healthy controls. All this evidence shows that although patients with JME have traditionally shown normal structural neuroimaging findings, they have a different brain structure than normal controls.…”

Development and Validation of MRI-Based Radiomics Models for Diagnosing Juvenile Myoclonic Epilepsy

“…During auto-segmentation, four patients with JME were excluded because of segmentation errors. From multiple segmentations of brain structures, 22 ROI masks were selected based on clinical evidence from previous JME imaging research: bilateral cerebral white matter [ 19 20 ], bilateral thalamus [ 7 21 ], bilateral caudate [ 22 23 ], bilateral putamen [ 7 24 ], bilateral globus pallidus [ 25 ], bilateral hippocampus [ 26 27 ], bilateral amygdala [ 9 28 ], bilateral ventral diencephalon [ 29 30 ], brainstem [ 31 ], and corpus callosum (anterior, mid-anterior, central, mid-posterior, and posterior) [ 32 33 ]. Their clinical relevance has been established through a review of published studies [ 34 35 ].…”

“…Computational MRI studies using voxel-based morphometry, diffusion tensor imaging, and functional MRI have shown changes in the cortical/subcortical volume and morphology, thalamocortical connectivity, and structural-functional correlations [ 3 4 5 ]. In contrast, previous studies have mainly focused on single regions of interest (ROI) (thalamus [ 6 ], putamen [ 7 ], corpus callosum [ 8 ], amygdala-hippocampus [ 9 ], and frontal cortex [ 10 ]) or single parameters (volume, morphology, probabilistic tractography connectivity, and blood-oxygen-level-dependent contrast).…”

The conundrum of neuropsychiatric systemic lupus erythematosus: Current and novel approaches to diagnosis

“…Most of these studies of NM-SPECT, however, are a decade old, so future studies should consider assessing the utility of combined SPECT-CT or SPECT-MRI for attenuation correction and image co-registration in NPSLE cohorts (Figure 2). F-18 fluorodeoxyglucose (FDG) PET on NPSLE cohorts have demonstrated various regional hyper-or hypometabolic changes, commonly in the temporal, occipital and frontal lobes, which have also shown associations with impaired memory and mood disorders (148)(149)(150). Although no associations with SLEDAI scores have been observed, serial PET imaging in a small study demonstrated normalization following improvement of neuropsychiatric symptomatology (151).…”