| Background and ObjectiveEpilepsy refers to the cerebral cortex neurons by abnormal discharge excessive synchronization caused a series of clinical syndrome,according to the latest statistics show that China’s domestic epilepsy prevalence of 7‰,active epilepsy prevalence was 4.6‰,the annual incidence of 28.8/100000,estimates there are 9 million people with epilepsy,1/5-1/6 of the world patients,number of new patients each year about 400000 people at the same time.Despite the long-term treatment with traditional antiepileptic drugs,there are still nearly 20%-30% of patients with refractory epilepsy who are not sensitive to drug treatment.And quite a few patients with intractable epilepsy can be treated by craniotomy and achieve the goal of epilepsy control.The core of the surgery is to remove the epileptogenic lesion and block the discharge conduction pathway so as to reduce abnormal discharge,which requires us to accurately locate the epileptogenic lesion.With the development of science and technology,the rapid progress of neuroelectrophysiology and neuroimaging,as well as the development of microsurgery,epilepsy surgery technology tends to mature,especially the application of electroencephalography in epilepsy surgery,which is of great significance for the development of epilepsy surgery.Although routine scalp electroencephalogram is one of the most important methods for preoperative evaluation of epilepsy,it is affected by many factors,such as scalp,skull,electromyographic activity and motor artifact,and has low temporal and spatial resolution,which affects the location of epileptiform discharge starting area.The application of intracranial subdural electrodes,however,avoids this drawback and is recognized as the "gold standard" for the localization of epileptic lesions.In recent years,the accuracy of the intraoperative electrocorticography(ECoG)monitoring and localization of epileptic lesions and its value in the intraoperative evaluation of epileptic lesions in secondary epilepsy have been questioned by some scholars.This study was divided into two parts.In the first part,the surgical prognosis of secondary epilepsy under ECoG monitoring and simple primary focus resection was retrospectively analyzed,and the application value of ECoG in secondary epilepsy and the influencing factors of postoperative seizures were discussed.In the second part,the accuracy of ECoG localization for epileptic foci was evaluated by comparing the results of intraoperative long-term monitoring of ECoG and intracranial electrode implantation.PART ONE To investigate the value of cortical electroencephalography(ECoG) in surgical treatment of secondary epilepsy and the influencing factors of postoperative seizures.ObjectiveTo investigate the value of cortical electroencephalography(ECoG)in surgical treatment of secondary epilepsy and the influencing factors of postoperative seizures.Materials and MethodsClinical data of 113 cases of secondary epilepsy treated by surgery in the department of neurosurgery of our hospital from January 2015 to January 2018 were collected.All patients underwent preoperative electroencephalogram,CT,MRI and other imaging examinations,and were followed up for 1-3 years after surgery.The eclampsia focal points were divided into monitoring group and control group according to whether the eclampsia focal points were treated under ECoG monitoring during the operation.60 patients in the monitoring group received multiple ECoG monitoring after the focus resection.According to the results and clinical manifestations of ECoG monitoring,the eclampsia focal points were located again and appropriate surgical treatment was selected.In the control group,53 patients underwent primary lesion resection under the microscope,and eclampsia foci were not monitored and treated by ECoG.According to whether the patients had seizures after surgery,they were divided into seizure group and non-seizure group,and the general data and clinical indicators of the two groups were analyzed to explore the factors affecting the prognosis of secondary epilepsy.ResultsThe χ2 test(χ2=13.373 P=0.000)was performed on the epilepsy control of the two groups(>1 year after operation).The difference was statistically significant,suggesting that the control of epilepsy in the monitoring group was better than that of the control group.Univariate analysis of factors that may cause postoperative seizures,the main site of the primary lesion(χ2=16.8.5 P=0.019),whether the lesion was completely cut(χ2=6.266 P=0.012),the difference was statistically significant.significance.The statistically significant factors for univariate analysis were analyzed by general multivariate logistic regression analysis.The results showed that intraoperative ECoG monitoring was a risk factor for postoperative seizures in secondary epilepsy.ConclusionsIntraoperative ECoG monitoring can assist in locating epileptic foci and improve the efficacy of surgical treatment for secondary epilepsy.Intraoperative ECoG monitoring can detect the residual discharge after the primary lesion resection,and guide the operation to remove the primary lesion and the epileptogenic lesion to the maximum extent on the premise of protecting the important functional areas.The primary lesion or the main part of the lesion in the temporal lobe can be better controlled after the seizure.PART TWO Comparative study of intraoperative ECoG monitoring and intracranial electrode burial localization ObjectiveBy comparing the results of intraoperative ECoG and intracranial electrode burial and localization of epileptogenic focus,the value of ECoG in localization of epileptogenic focus in epilepsy surgery was explored.Materials and MethodsRetrospective study of clinical data of 12 cases of MRI-negative refractory epilepsy buried in our department from January 2013 to August 2016 in our department,collecting EEG data of intracranial electrode burial records,surgery EEG data in ECoG.Statistical analysis was used to analyze the relationship between amplitude and frequency of abnormal discharge(ID)and abnormal interictal discharge(IED)in the long-term intracranial electroencephalogram(EGE),and the results of ECoG monitoring.Comparison.ResultsIn long range EEG with intracranial electrode implantation,there was a significant difference in the frequency of ieds at the onset area and at the non-onset area(P<0.05).The area under the ROC curve was 0.984 and the standard error was 0.014 when standardized IED frequency was used as the index to determine the onset origin point,which was of high diagnostic value.There was a significant difference in IED amplitude between the onset and non-onset onset regions(P<0.001).Intraoperatively,the frequency of ECoG IED monitoring was significantly lower than the long range monitoring with buried electrodes(Fisher’s precise test P=0.027 P<0.05).Among the 6 patients in the "frequent" and "multiple" ECoG monitoring groups,5 patients were correlated with the intracranial long-range EEG monitoring results(P<0.001),while only 1 patient in the 6 patients in the "rare" monitoring group was correlated with the intracranial long-range EEG monitoring results(P<0.001).Intraoperatively,ECoG monitored 6 patients with "frequent" and "multiple" ieds,and 5 patients with the highest frequency electrode point were in the ID onset area,while 2 of the 6 patients in the "less frequent" group were in the ID onset area.Conclusions 1.In the long-term monitoring of intracranial electrode implantation,it is of high significance to determine the eclampsia kitchen with interepisode IED.2.The IED frequency of intraoperative ECoG monitoring is susceptible to interference,and the IED frequency is significantly reduced compared with the intracranial electrode burial.3.When the intraoperative ECoG monitors the IED frequency>5 times/min,it can be used as the origin of the ID,suggesting to locate the epileptogenic focus. |
PDF Full Text Request