White Matter Functional Network In Patients With Generalized Tonic-Clonic Seizures

The main clinical symptom of epilepsy with generalized tonic-clonic epilepsy(GTCS)is generalized seizures,and its seizures of pathophysiology have not been fully clear.A large number of previous studies have found abnormalities in the cortical-cortical network and thalamus-cortical network in patients with epilepsy,most of these studies were focus on the functional of gray matter and the structure of white matter,while there have been few studies on the functional of white matter.However,recent studies have shown that white matter exhibits similar blood oxygen level dependent signal fluctuations as gray matter.Therefore,this article aims to specifically study the changes of white matter function signals in patients with GTCS.In this study,we recruited 88 subjects,including 57 patients with GTCS and 31 age and sex-matched healthy control.Due to some patients took antiepileptic drugs,we divided these patients into new onset drug native GTCS patients(32 cases)and antiepileptic GTCS patients(25 cases).Collect their resting-state functional magnetic resonance data and high-resolution T1 image data.Using the clustering method,we divided all white matter voxels into several white matter networks,and then used the Amplitude of low-frequency fluctuation(ALFF)algorithm to explore the intrinsic neural activation of each white matter network.By using one-way analysis of variance to compare the differences between the three groups of antiepileptic GTCS patients,new onset drug native GTCS patients and the healthy control,we found deep networks and temporal lobe frontal networks,Anterior radial crown network,temporal lobe network,Deep network,Tempofrontal network,Anterior corona radiate network,temporal network,Superior corona radiate network,Posterior callosum network,Orbitofrontal network,Anterior callosum network,Pre/postcentral network,and Cerebellar network have significant group effects.The post-hoc analysis showed that new onset drug native GTCS patients had a significantly decreased ALFF value,compared with antiepileptic GTCS patients and healthy control;while antiepileptic GTCS patients compared with healthy control,the ALFF value no obvious difference.The widely reduced ALFF values in these results indicate that the white matter function is impaired at resting-state,and the abnormal activation of intrinsic nerves may be caused by seizures.To further study the white matter function network characteristics of GTCS patients,we use graph theory to construct several network topological attributes to evaluate abnormalities of white matter network of GTCS patients.First,we refer to the white matter fiber bundle template of JHU ICBM-DTI-81 to define the network nodes.These fiber bundle templates produced a total of 48 network nodes and were applied to each subject.Secondly,the blood oxygen level-dependent signals in each verified white matter fiber bundle are averaged,and the Pearson correlation coefficient between the average signals is calculated.In the end,for each participant,we got a 48 × 48 correlation matrix and used this matrix to evaluate the characteristics of the white matter network.The study found that the three groups of new onset drug native,antiepileptic GTCS patients and healthy control all showed small world attributes.One-way analysis of variance found that some of the network topological properties have changed significantly in new onset drug native GTCS patients,compared with antiepileptic GTCS patients and healthy control.In the GTCS patient,the new onset drug native GTCS patient has a significantly reduced clustering coefficient,local efficiency and global efficiency,as well as a significantly increased path length.Significantly lower the clustering coefficient may reflect that the local connection of the white matter functional network of new onset drug native is more dispersion.The significantly reduced local and global efficiencies indicate a decrease in the default fault tolerance of the white matter function network of new onset drug native GTCS patients and the ability to process information.The significantly increased path length reflects the reduced ability of the white matter function network of new onset drug native GTCS patients to spread information in parallel,and the efficiency of disseminating information.In summary,the widely reduce ALFF of functional networks of white matter,lower clustering coefficient,local and global efficiency and higher path length were found in new onset drug native GTCS patients.These results indicated that the function of white matter in onset drug native GTCS patients were abnormal.And our study provided valuable information for understanding the pathophysiological mechanisms of patients with GTCS and provided evidence for the function of whiter matter in GTCS.