Study Of Brain Functional Network In Patients With Epilepsy Relapse After Withdrawal Based On Resting State Functional Magnetic Resonance Imaging

Objective:The aim of this study is to investigate the abnormal functional brain regions and neural network features associated with seizure recurrence in patients with epilepsy after drug withdrawal based on resting-state functional magnetic resonance imaging,and to search for potential imaging markers that can early predict patients with seizure recurrence after drug withdrawal in terms of functional brain networks and to elaborate on the mechanisms by which they may occur.Methods:A GE Discovery MRI 750 W 3.0T superconducting magnetic resonance imaging machine with preset parameters was used to perform resting-state functional magnetic resonance scans and obtain imaging data from 48 patients with epilepsy who met the criteria for medication reduction and withdrawal and were willing to withdraw their medication at the First Affiliated Hospital of Hainan Medical College.These patients were monitored for seizure recurrence during the follow-up period.27 patients had seizure free and 21 patients had seizure relapse after medication reduction and withdrawal,while 35 healthy control matched to the patients’ gender,age,education and handedness were recruited,and the same scanning protocol was used.The MRI data from the three groups were preprocessed using DPABI software based on the MATLAB 2018 platform.After excluding the unavailable resting MRI data,a one-way analysis of variance was performed using three analysis methods: regional homogeneity(Re Ho),amplitude of low frequency fluctuation(ALFF)and functional connectivity(FC)for the brain areas with statistically significant differences between the three groups.A two-sample t-test was then performed between the groups,and areas that met voxel significance <0.001,number of contiguous voxels ≥23,and clump significance <0.05 were considered statistically significant according to Gaussian random field theory.The SPSS 26.0 statistical software was also used to perform statistical analysis of general clinical information on the three groups of subjects.Results:After 48 withdrawn epileptic patients and 35 healthy volunteers completed resting-state functional MRI scans and extracted data,a total of 10 subjects(including3 with non-recurrent epilepsy,2 with recurrent epilepsy and 5 healthy controls)were preprocessed to exclude subjects with structural image deficits due to excessive head movement,resulting in the inclusion of a total of 24 patients in the seizure free group(SF group),19 patients in the seizure relapse group(SR group)and a total of 30 subjects in the healthy control group(HC group),which were entered into functional MRI data analysis and statistical analysis.There were no statistically significant differences between the three groups in terms of general clinical data(age at the time of scanning,gender and other clinical variables)(P>0.05),and there was a statistically significant difference between the SR and SF groups in terms of follow-up time(P=0.027).Resting-state functional MRI results revealed: 1.Re Ho value analysis:(1)Compared to the HC group,patients in the SR group had increased local consistency in the right temporal lobe,bilateral precuneus,right middle occipital gyrus,left inferior occipital gyrus,left cuneus,left syrinx,left postcentral gyrus,left superior parietal gyrus and other brain regions,and increased local consistency in the bilateral anterior cingulate and paracingulate gyri,bilateral superior frontal gyrus,left orbitofrontal middle gyrus,right middle occipital gyrus In the non-recurrent group,no brain regions with increased local consistency were found,but decreased local consistency was found in the left medial superior frontal gyrus.(2)Compared with patients in the SF group,patients in the SR group had increased Re Ho values in the right superior occipital gyrus and decreased Re Ho values in the right middle temporal gyrus and right inferior temporal gyrus.2.Analysis of ALFF values:(1)Compared with the HC group,brain areas with increased ALFF values in the SR group were mainly located in the left precuneus and left cerebellar crest,while brain areas with decreased ALFF values were in the right insula;in the SF group,ALFF values in the right middle temporal gyrus were increased,while those in the right anterior cingulate and right inferior temporal gyrus were decreased.increased and the right anterior cingulate and paracingulate gyrus ALFF values decreased;(2)the brain areas with increased ALFF values in the SR group compared to the SF group were in the left precuneus and the brain areas with decreased ALFF were in the right precuneus and the right middle temporal gyrus.3.Functional connectivity analysis:(1)compared to healthy controls,the epilepsy recurrence group had more extensive and dense functional connectivity within and between the networks of the default mode network and the task activation network.mainly showing a reduction in functional connectivity.(2)Compared to the non-recurrent group,the recurrent group showed enhanced functional connectivity mainly confined to the prefrontal cortex with the insula and parahippocampal gyrus,the dorsolateral prefrontal cortex with the parahippocampal gyrus,and the frontal visual area with the ventral occipital lobe.Conclusion:1.In patients with epilepsy in long-term remission,the more brain areas with abnormal resting-state brain activity,the greater the risk of recurrence after withdrawal,and the more abnormal functional activity in some brain areas remains irreversible and affects the normal state of several brain networks,and dysfunction in the cerebellum and occipital lobe may be the cause of recurrence.2.Patients with recurrent epilepsy have more extensive and dense functional brain connectivity,suggesting that hypersynchronization of brain networks causes such patients to be more prone to recurrence,while enhanced functional connectivity of the frontal and limbic systems may be a potential imaging marker for recurrence in patients with epilepsy after withdrawal of medication.3.Rs-f MRI is a new method for holistic evaluation of the functional brain network in patients with epilepsy and may provide a new theoretical basis for assessing whether patients with epilepsy have a relapse after withdrawal of medication.