White Matter Integrity in a Rat Model of Epileptogenesis: Structural Connectomics and Fixel-Based Analysis
| Autor: | Wytse Wadman, Robrecht Raedt, Marie-Gabrielle Goossens, Jean Delbeke, Benedicte Descamps, Christian Vanhove, Kristl Vonck, Emma Christiaen, Paul Boon |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
Connectomics
Technology and Engineering STRESS intraperitoneal kainic acid rat model structural brain connectivity graph theory Biology Epileptogenesis 050105 experimental psychology Temporal lobe diffusion MRI White matter 03 medical and health sciences 0302 clinical medicine Neuroimaging KAINIC ACID MODEL CONNECTIVITY Connectome Image Processing Computer-Assisted Medicine and Health Sciences TEMPORAL-LOBE EPILEPSY medicine Animals Humans 0501 psychology and cognitive sciences fixel-based analysis medicine.diagnostic_test General Neuroscience STATUS EPILEPTICUS 05 social sciences ANIMALS Brain Magnetic resonance imaging temporal lobe epilepsy White Matter Rats Diffusion Magnetic Resonance Imaging Diffusion Tensor Imaging SOCIAL-ISOLATION medicine.anatomical_structure Epilepsy Temporal Lobe SEIZURES Neuroscience 030217 neurology & neurosurgery Diffusion MRI Tractography |
| Zdroj: | BRAIN CONNECTIVITY |
| ISSN: | 2158-0022 2158-0014 |
| Popis: | Introduction: Electrophysiological and neuroimaging studies have demonstrated that large-scale brain networks are affected during the development of epilepsy. These networks can be investigated by using diffusion magnetic resonance imaging (dMRI). The most commonly used model to analyze dMRI is diffusion tensor imaging (DTI). However, DTI metrics are not specific to microstructure or pathology and the DTI model does not take into account crossing fibers, which may lead to erroneous results. To overcome these limitations, a more advanced model based on multi-shell multi-tissue constrained spherical deconvolution was used in this study to perform tractography with more precise fiber orientation estimates and to assess changes in intra-axonal volume by using fixel-based analysis. Methods: dMRI images were acquired before and at several time points after induction of status epilepticus in the intraperitoneal kainic acid (IPKA) rat model of temporal lobe epilepsy. Tractography was performed, and fixel metrics were calculated in several white matter tracts. The tractogram was analyzed by using the graph theory. Results: Global degree, global and local efficiency were decreased in IPKA animals compared with controls during epileptogenesis. Nodal degree was decreased in the limbic system and default-mode network, mainly during early epileptogenesis. Further, fiber density (FD) and fiber-density-and-cross-section (FDC) were decreased in several white matter tracts. Discussion: These results indicate a decrease in overall structural connectivity, integration, and segregation and decreased structural connectivity in the limbic system and default-mode network. Decreased FD and FDC point to a decrease in intra-axonal volume fraction during epileptogenesis, which may be related to neuronal degeneration and gliosis. Impact statement To the best of our knowledge, this is the first longitudinal multi-shell diffusion magnetic resonance imaging study that combines whole-brain tractography and fixel-based analysis to investigate changes in structural brain connectivity and white matter integrity during epileptogenesis in a rat model of temporal lobe epilepsy. Our findings present better insights into how the topology of the structural brain network changes during epileptogenesis and how these changes are related to white matter integrity. This could improve the understanding of the basic mechanisms of epilepsy and aid the rational development of imaging biomarkers and epilepsy therapies. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|