The New Applications Of EEG Technology For Identification In Epilepsy Patients’ Sleep Disorders, Cognitive Disorders’ And Epileptiform Event

Background and purpose：Epilepsy patients are often complicated with sleep disorders, cognitivedysfunction, and are often induced with status epilepticus easily, which may affecttheir life-quality seriously, even threat their lives. Neurons’ abnormal discharge isthe basis for epileptic seizures, EEG technology is an objective method to detect theabnormal epileptiform discharges, on the basis of traditional EEG technology, wehave made some improvements, such as increasing the number of sleep parameters,quantitative analysis and trend analysis, in order to explore the relationship betweenepileptiform discharges and sleep-wake cycle, the epileptiform discharges andcognitive function, and also the relationship between epileptiform discharges andfrequent epileptic seizures.Method：1. In the part of exploring the relationship between epileptiform discharges andsleep-wake cycle: We have added sleep parameters such as eye movement and EMGto the traditonal EEG technology, and applied to the200cases of epilepsy patientsand182cases of healthy controls, after the24h-monitoring, we made an analysis ofepileptiform discharges and sleep architecture, sleep phase, then explored therelationship.2. In the part of exploring the relationship between the epileptiform dischargesand cognitive function: We have included67cases of epilepsy patients withcognitive impairment, after the24h-EEG monitoring, we used quantitative analysismethod to define the epileptiform discharges index, and gave the cognitive-relatedneuropsychological tests to these patients with different index of epileptiformdischarges,then explored the relationship. 3. In the part of exploring the accuracy of trend-CDSA, aEEG applied in theidentification of epileptic seizures: We have selected30continuous24h EEGrecording datas (20data contained epileptic seizures,10data were normal controls),three electrophysiology physician have been trained to use CDSA and aEEG tointerpret these30EEG recordings, and marked any suspected epileptic seizure, afterthe interpretation by CDSA and aEEG, three electrophysiology physician usedconventional EEG reading to identify the real number of seizures, then comparedCDSA and aEEG with conventional EEG to determine the sensitive rate,misdiagnosis rate, missed diagnosis rate, and also made a statistical analysis ofconsistency between the different reviewers.Results：1. In the part of exploring the relationship between epileptiform discharges andsleep-wake cycle: We found that about91%of epilepsy patients can be found withepileptiform discharges under the EEG monitoring; the epileptiform discharges ratein waking-phase, sleep-phase, both waking and sleep stage Ⅰ-Ⅱphase was7.1%,19.2%,25.3%respectively; epileptiform discharge rate in sleep stage Ⅲ-Ⅳ was1.1%; there was no significant difference of total sleep time between epilepsy groupand control group, there was also no significant difference of REM sleep time (P>0.05); sleep time of stage Ⅰ-Ⅱin epilepsy patients group was longer than controlgroup (293.91±27.57min vs223.17±15.28, P=0.000), sleep time of stage Ⅲ-Ⅳin epilepsy patients group was shorter than control group (50.11±12.12min vs133.96±10.77, P=0.000); besides this, asymmetric spindles have been found in26.7%of epilepsy patients, fragmented sleep architecture with a higher rate ofsleep-phase transformation have been found in43.3%of epilepsy patients.2. In the part of exploring the relationship between the epileptiform dischargesand cognitive impairment: The index of10%of epileptiform discharges has anegative effect on cognitive function in adult epilepsy patients, the index of10%wasthe minimum study point; different index of epileptiform discharges have differentnegative impact on the cognitive function (72.13±10.3vs85.20±9.65, P=0.02); there was no difference in the different distribution of epileptiform discharges withnegative impact on cognitive function, such as focal and multifocal epileptiformdischarges, generalized epileptiform on cognitive function (WAIS-RC:86.11±11.3vs84.04±10.8, P=0.35; WMS:84.23±9.6vs82.31±10.23, P=0.35); there wasno difference in the different duration of epileptiform discharges with negativeimpact on cognitive function.3. In the part of exploring the accuracy of CDSA, aEEG applied in theidentification of epileptic seizures: In our study, we have obtained a highersensitivity and lower misdiagnosis rate and missed diagnosis rate; when using theCDSA to interpret, the sensitivity was80%, misdiagnosis rate in24hours was low,about four times per24h; when using aEEG, the sensitivity was81.3%,misdiagnosis rate in24hours was2times per24h; when using CDSA and aEEG tointerpret, misdiagnosis rate was about4times per24h respectively, and there was nodifference between CDSA and aEEG (P>0.05, X2); besides this, when threeelectrophysiological physicians using CDSA and aEEG to interpret sensitive rate,misdiagnosis-rate and missed diagnosis rate, there was a better consistency,consistency parameters are κ=0.52and κ=0.68respectively when using CDSA andaEEG.Conclusion：1. In previous, routine EEG technology can be applied for the detection ofepileptiform discharges, but the structural analysis for the sleep requires the use ofsleep monitoring technology. Combing EEG technology with sleep parameters cananalyze the relationship between the epileptiform discharges and sleep-wake cycle,and can contribute to the early identification of sleep disorders in epilepsy patients,early treatment programs will be made to develop and improve their life quality.Such studies are few and no large-scale clinical studies have been foundcurrently,howecer, in our study, we have included a large amount of clinicalsamples, and various seizure types.2.The combing EEG technology with quantitative analysis, can make a quantitative analysis of the minimum epileptiform discharges index, which can leadto impaired cognitive function in epilepsy patients,can also find potential andhidden factors of epileptiform discharges in epilepsy patients with cognitiveimpairment, for the controversial issue of clinical treatment " whether there was aneed for early intervention epileptiform discharges in order to delay or reduce thenegative impact on cognitive function " provided a theoretical basis. Such studieshave been reported domestic and foreign rarely, and have different thresholds.3. The application of EEG trend-CDSA and aEEG in recognition of epilepticseizures has a high sensitivity, low misdiagnosis rate and missed diagnosis rate, andwhich was convenient and easier to operate, and in favor of widely application inICU by non-professional reviewers. In previous, such methods were used in themonitoring of sleep-wake cycle in newborn, neonatal cerebral function monitoringfor intensive brain injury, the monitoring of anesthesia depth, fewer studies havebeen done in adult intensive care, and showed different results.