The Recording Latency For Interictal Epileptiform Discharges And Epileptic Seizure In Epileptic Patients---a Video-EEG Study

Objective:to observe the proportion of interictal epileptiform discharges spike and epileptic seizure, and the recording latency for the first interictal epileptiform discharges spike and epileptic seizure in epileptic patients in long-range video electroencephalogram (VEEG); moreover, to observe the influence of sleep cycle, epilepsy type, the purpose of attendance and MRI results on recording latency.Methods:reviewed the clinical data and MRI results of the patients who were undergoing VEEG from March2012to September2013in epilepsy center of our hospital. All patients received at least24hours (h) or more consecutive VEEG recording, accumulative EDst and ESst, hereinafter referred to as Re-and Rs-, proportion calculated according to the time period respectively within24h.The purpose of the patient is classified as followings:1. Clarify epilepsy diagnosis,2. Epilepsy preoperative evaluation,3. medical adjustment. MRI results of patients are classified as followings:1. Responsibility lesions,2. No responsibility lesions,3. Without the MRI data.Results:the total434patients were treated within18months, while350patients, with complete data, are diagnosed as epilepsy (80.6%). Within the350patients, the purposes of165cases were for clarifying epilepsy diagnosis,124cases were for epilepsy preoperative evaluation, and61cases were for drug adjustment. Within the350patients,232cases have records of IEDs within24h and the percentage of patients, the purpose of whom was for diagnosing and adjusting the drug for medical, were significantly lower than the proportion of patients with preoperative evaluation;126cases have the records of ES within24h, with a diagnosis of purpose (59.4%) and adjust the drug for medical purposes proportion (57.4%) were significantly lower than in patients with preoperative evaluation of patients with proportion (79.8%). Regradually increased to58.9%within8h, and then to be stable afterwards. Only12cases (16.4%) of the73patients, who did not have the record of IEDs within24h, can record the IEDs after another24h measurement; For all patients with epilepsy, Rs continuously increased obviously within24h, for patients who were not recorded ES within24h,28.3%of patients can record ES in another24h. It shows that the phase of sleep is very important to the recording of IEDs,46.6%of people with epilepsy record IEDs needs including sleep,26.2%of patients record ES needs including sleep, and mainly in stagell sleep. For comprehensive epilepsy, the latency of EDst within24in comprehensive epilepsy was shorter than that of partial epilepsy. We found that the MRI results had affected on the recording of IEDs. Of all the349patients with epilepsy,98patients had found responsibility lesions (MRI+group) by head MRI,174cases of patients with MRI lesions had not found responsibility or exist only nonspecific change group (MRI-), and the other77patients didn’t have the MRI data. The percentage of patients, who had recorded IEDS within24h, in MRI+group was90.8%, while the percentage of MRI-group was67.8%; The percentage of the patients, who had the records of ES within24h, in MRI+group was54.1%, while the percentage of MRI-group was33.9%.232/231cases of Epilepsy patients recorded IEDs within24h (for the purpose of diagnosis in98cases, MRI+group,89cases),126cases recorded ES (for the purpose of diagnosis in49cases, MRI+group,53cases)). The cumulative proportion of the patients of MRI+group was the highest in each time period, while the trend tended to be stable after Re-8h reach83.7%. ES occurred in Rs-40min MRI+group, and it increased suddenly after4h, Rs-24h54.1%patients of MRI+group recorded ES. Conclusion:After eight hours, the possibility of epilepsy recorded sample discharge is small, and a period of VEEG which is at least including stage2NREM sleep phase can increase the positive rate of diagnosis; Patients who were diagnosised as refractory epilepsy would record IEDs more frequently, which were also easier to record ES; Responsibility of lesions on MRI(MRI+) were much more likely to record IEDs and ES, however, no no responsibility of lesions on MRI(MRI-) need a longer recording time.