Altered Structural Brain Network Topology In Patients With Juvenile Myoclonic Epilepsy Using Diffusion MRI

JME is characterized by generalized tonic-clonic seizures and the myoclonic jerks of proximal upper limb.Previous studies have demonstrated that white matter alterations based on DTI or DTI-derived FA in patients with JME.However,it is known that DTI has the limitation to resolve the intravoxel fiber heterogeneity,and FA is a kind of comprehensive parameter fail to representing histological features.The paper constructed three brain structural networks of JME patients using diffusion MRI methods: QBI,GQI and NODDI firstly.The study employed QBI for whole brain tractography to overcome the limitation of DTI,and utilized QA derived from GQI,ICVF derived from NODDI for quantitative analysis of networks.Using 90 brain regions as nodes,and the weighted average QA,ICVF or binary values of the fiber connecting the brain regions as edges of brain networks,the study respectively examined the network measures and network edges by different methods to explore the brain white matter alterations of JME patients.The results showed that the significant difference in the global network measures of JME were only found in the ICVF matrices.The local measures of three networks all showed the significant change in the central region,the limbic lobe,the frontal lobe,the lateral and orbital temporal lobe,and the lateral parietal lobe.The results in the ICVF network were more obvious.An abnormal subnetwork was found in ICVF network,but no in QA network.The results showed that brain white matter structure of JME is damaged within the scope of the whole brain,which is mainly caused by the loss of the neuro and decreased fiber density.And the results show that ICVF is a more sensitive measure than QA,which highlights the abnormal brain regions of JME patients.The results support that JME is a cortical disorder rather than cortex-thalamus disorder.And the results support that topological and connective abnormalities in the frontal lobes play an important role in the pathogenesis of JME patients.