Objective To explore the change of EEG waveform recorded by clinical EEG under different filtering parameters. Methods22 abnormal EEG samples of epilepsy patients with abundant abnormal waveforms recorded in Peking University first hospital were selected as the case group (abnormal group), and 30 normal EEG samples of healthy people with matched sex and age were selected as the control group (normal group). Visual examination and power spectrum analysis were then performed to compare the difference of wave forms and spectrum power under different settings of filter parameter between the two groups. ResultsThe results of visual examination show that, lower high-frequency filtering has an effect on the fast wave composition of EEG and may distort and reduce the spike wave. Higher low-frequency filtering has an effect on the overall background and slow wave activity of EEG and may change the amplitude morphology of some slow waves. The results of power spectrum analysis show that, Compare the difference between the EEG normal group and the abnormal group, the main difference under the settings of 0.5~70Hz was on the θ and α3 frequency band, different brain regions were slightly different. In the central region, the difference in the high frequency band (α3, γ1, γ2) decreases or disappears with the decrease of the high frequency filtering. In the rest of the brain, the difference in the δ band appears gradually with the increase of the low frequency filtering. Compare the difference between frontal area and occipital area under different filter set, for the normal group, under the settings of 0.5 ~ 70 Hz, the difference between two regions is mainly on the θ, γ1 and γ2 band. When high frequency filter reduces, the difference between two regions on high frequency band (γ1, γ2) are gradually reduced or disappeared. And when low frequency filter increases, the difference on δ band appears. For the abnormal group, the difference between frontal and occipital region under the settings of 0.5 ~ 70 Hz is mainly on γ1 and γ2 bands. When the high-frequency filter decreases, the difference between two regions on high-frequency bands are gradually decreased or disappeared. All the results can be corrected by FDR. ConclusionThe results show that the filter setting has a significant influence on EEG results. In clinical application, we should strictly set 0.5 ~ 70 Hz bandpass filtering as the standard.
ObjectiveTo investigate the lateralization of ictal scalp EEG in different times in focal epilepsy.Methods356 surface ictal EEG of 41 patients were reviewed retrospectively in focal epilepsy arising from the mesial frontal, lateralfrontal, mesialtemporal, neocorticaltemporal, insular lobes and posterior cortex from July, 2010 to at, 2016. Each ictal scalp EEG was subdivided into ten epoches (E1-E10), then the lateralization of every epoch was analyzed. Ten epochs EEG were merged into three timesas E1-E3, E4-E6 and E7-E10. The ratio of lateralization, mislateralization and non-lateralization of each timeEEG were studied. Ictal onset zone (IOZ) were precise localized by intracranial EEG. The results of epileptogenic zone corresponded with surgical outcomes as seizure free or decreased.Results62% seizures were lateralized by surface ictal EEG in all epilepsies. Lateralized ictal scalp EEG were seen in nearly 80% of seizures in all times in temporal lobe epilepsy (TLE). The highest lateralization of 89% occurred inE4-E6 andfalse lateralization up to 30% in E1-E3 in mesial temporal lobe epilepsy (MTLE), whereas 95% lateralized seizures emerged in E1-E3 in neocortical temporal lobe epilepsy (NTLE). Apparent non-lateralization in all times were higher than lateralization in frontal lobe epilepsy (FLE), especially in mesial frontal lobe epilepsy (MFLE). Lateralization in E1-E3 was only 24% higher than other times. In addition, False lateralization never occurred in all times in lateral frontal lobe epilepsy (LFLE). There were maximum of 83%lateralized seizures in E1-E3 in LFLE and 93% in E1-E3 in posterior cortex epilepsy (PCE). Seizures arising from insular lobe epilepsy (ILE) tendedto predict less lateralization in all times.ConclusionsIctal scalp EEG of E1-E3 are valuable in the lateralization in all epilepsies particularly in LFLE, NTLE and PCE. Lateralized E4-E6 and E7-10 are very useful in MTLE.
ObjectiveTo explore the application value of MRS combined with VEEG on the surgical treatment of temporal lobe epilepsy.
MethodsThere were 31 males and 20 females, age between 4 and 62 years.Their illness duration ranged from 4 to 10 years.The clinical manifestations showed complex partial seizure in 10 cases, secondary generalized seizure in 12 and generalized tonic-clonic seizure in 29. Based on their results of clinical manifestations, MRS and VEEG results, all the patients underwent anterior temporal lobectomy(including the most parts of the hippocampus and amydala).
ResultsThe follow-up of 1~3 years after the operation showed seizure free in 36 cases(Engle Ⅰ), and significant improvement in 11(Engle Ⅱ), no improvement in 4 cases(Engle Ⅳ). The overall effective rate was 92.16%.
ConclusionsMRS combined with VEEG has significant localization value for temporal lobe epilepsy. The prognosis of postoperative result is quiet good to the patient of typical temporal lobe epilepsy after anterior temporal lobectomy.
Objective
To investigate the clinical and EEG characteristics, therapeutic response and prognosis in children with atypical absence seizures.
Methods
The clinical and EEG data of 43 children with atypical absence seizures in Qilu Hospital, Shandong University during January 2011 to December 2016 were analyzed, and therapeutic response and prognosis were followed up.
Results
Childre were 24 male and 19 female with the mean age of 5.43 y. The onset ages were from 1 years and 8 months to 10 years and 3 months. All of the 43 patients had MRI examines, and 18 children were normol. MRI abnormalities appeared in 25 children, including cerebral cortical dysplasia and cerebral atrophy (13 cases), congenital corpus callosum hypoplasia (2 cases), and abnormal signal in bilateral posterior putamen (2 cases), encephalomalacia focus(4 cases), ventricle expention (2 cases), hydrocephalus(2 cases). All the children underwent EEG more than once. All children had atypical absence seizures during daytime. Children had slowly backgrounds in retesting EEG, and spine and slow waves of 1.5 Hz to 2.8 Hz could be seen in all the atypical absence seizures. All children were followed up, and except 6 children with complete control, 19 children’ parents reported seizure- free, 18 children have poor effect. Forty Children had various degrees of psychological abnormalities and motor regression. Among them 13 cases had psychological abnormalities and motor regression before disease; cognitive ability of 27 cases were normal before onset age, however, about 75% to 95% of the children became abnormal 2 years after atypical absence seizures. The rest 3 cases had no obviously impairment.
Conclusions
Most of the atypical absence seizures children had small onset age and high incidence in mental damage and cognitive impairment. The course of typical absence seizures aggravate gradually, and often develops to nonspecific brain damage in this process. Antiepileptic drugs can reduce the frequency of the seizure in part of the patients, but had no effect on psychological and motor regression.
It is an important means to study the electrical activity of the brain's nerve cells by exploring physiological information of the EEGs from the frequency domain. The gravity frequency is one of the global parameters with using this method. We used the multitaper spectrum method (MTM) spectrum estimation method of good performance to calculate the EEG spectrum and its gravity frequency of subjects under vigilance and vigilance decrement state. The results showed that the gravity frequency of vigilance state was higher than that of vigilance decrement state, the gravity frequency became smaller along with the vigilance decrement, and the location of the gravity frequency shifted to the left in the spectrum. Finally, the monitoring curve of the gravity frequency was acquired by designing an algorithm, and it was used to online monitoring vigilance operators.
ObjectiveThe purpose of this study was to investigate the autoimmune encephalitis (AE) seizure types and EEG characteristics and the value of diagnosis.
MethodsFifteen AE patients were hospitalized in the Department of Neurology at the First Hospital of Jilin University from November 2012 to July 2014. Data from their clinical manifestations, seizure types, EEG characteristics and laboratory investigation were analyzed.
ResultA total of 15 patients, 5 males and 10 females, aged 19-75 years were included. Eight cases of anti-NMDA receptor encephalitis, five cases of LGI1 receptor encephalitis and two cases of anti-Hu antibody encephalitis were diagnosed clinically.①Anti-NMDA receptor encephalitis:seven patients had seizures, which inclued complex partial seizure, generalized tonic-clonic seizure, simple partial seizure and status epilepticus.Three patients had extreme delta brush.②LGI1 receptor encephalitis:two cases had seizures, while four cases with FBDS. Sharp and slow waves with irregular delta waves appeared in bilateral temporal areas in EEG of three cases, while one case showed clinical seizure. Two cases detected "limb shaking and others" attack, but the corresponding EEG showed no abnormalities.③Anti-Hu antibody encephalitis:one case showed seizures, the EEG showed a lot of sharp and slow waves with irregular delta waves in bilateral temporal areas, while one case showed sharp and slow waves.
ConclusionAnti-NMDA receptor encephalitis can present with various types of seizures and non-convulsive status epilepticus, interictal extreme delta brush is more specific. It has important value. LGI1 receptor encephalitis is characterized by FBDS, it has important clinical significance.Anti-Hu antibody encephalitis lesions diffuse distribution, clinical manifestations are different. It may be associated with seizures, seizure types are not-specific.It may have slow waves or sharp and slow waves.
ObjectiveTo explore the technique of preoperative evaluation of video electroencephalography (VEEG) electrode fixation method.MethodsThe electrode fixation method was modified using a simple and easy-to-manufacture 3M decompression sticker designed by ourselves.ResultsUsing the modified electrode fixation method, compared with the traditional fixation method, the electrode displacement, shedding rate and pain score of the children were significantly lower (P<0.05). The incidence of skin pressure sore by traditional fixation method was 7.03%. The rate of improvement after release was 3.37%. Although it was not statistically significant, the incidence of pressure ulcers were reduced.ConclusionsEffectively reduce the adverse reactions such as electrode displacement, shedding, pain and skin pressure sore caused by wearing the electrode for a long time. It has the advantages of being simple, fast, safe, stable and humanized, and it is worthy of clinical promotion.
Epilepsy has been recognized as a brain network disorder. Therefore, functional MRI (fMRI)-based connectivity is an ideal technique for exploring the complex effects of epilepsy on the brain. Functional connectivity studies have provided insights into the physiopathogenesis of the epileptic network underlying focal epilepsies, genetic generalized epilepsy, and specific epileptic syndromes. An increasing number of studies have focused on the deleterious effects of epilepsy on other brain networks to help to explain cognitive deficits and psychiatric symptoms. Anti-epileptic treatment studies have yielded information about the side effects and the restoration of functional abnormalities after using the drug. Researchers who have examined predictors of surgical outcomes have suggested that there might be identifiable pre-surgical patterns of functional connectivity that are associated with a greater likelihood of positive cognitive or seizure outcomes. However, knowledge regarding the role of fMRI connectivity remains limited in clinical settings. Further validation through invasive investigations and follow-up studies is required for its reliable application in the clinical management of individual patients. (C) 2016 Published by Elsevier Ltd on behalf of British Epilepsy Association.
ObjectiveTo explore the clinical value of SEEG-guided radiofrequency thermocoagulation therapy in patients with posterior cortex epilepsy.MethodsA case of epilepsy secondary to viral encephalitis was reported in this paper, SEEG implantation confirmed that the seizure began in bilateral posterior head, and the right posterior head was the main area of disabling lesion. After a series of complete preoperative neuropsychological assessment, the right posterior head was found to have functional retention. Therefore, we used a minimally invasive radiofrequency thermocoagulation therapy to damage epileptic foci.ResultsThe patient were followed up for 2 years after operation, the seizure frequency were significantly reduced, and the patients did not show symptoms of functional loss.ConclusionPosterior cortex epilepsy is common in neonates with brain injury. The localization and lateralization of operation is difficult because its EEG showed bilateral discharges, or the seizures start from both sides of posterior head, meanwhile, posterior head involves functional areas, which makes the operation even more difficult. This minimally invasive treatment destroys the lesion and maximizes the protection of the patient's functional areas, which provides a new surgical approach for bilateral posterior cortex epilepsy in the future, especially for symptomatic epilepsy caused by hypoxic-ischemic brain injury and encephalitis.
ObjectivesPost-encephalitic epilepsy could be of great chance of pharmaco-resistant, even surgery may not achieve seizure free. The aim of this study is to mapping epileptogenic area of pharmaco-resistant post-encephalitic temporal lobe epilepsy, to find whether "temporal plus" epilepsy is the main type and its surgery outcome, based on stereo-EEG(SEEG) study.MethodWe retrospectively studied 15 patients with pharmaco-resistant temporal lobe epilepsy. Scalp EEG, seizure semiology, MRI, FDG-PET, and SEEG were reviewed for all patients. According to epileptogenic area which was analysed by SEEG, 15 patients were divided into 2 groups, temporal lobe epilepsy(TLE) group and temporal plus epilepsy(TPE) group. Clinical characteristics were compared with each group, by t-test or Fisher exact test when data needed.ResultsThere were 8 patients in TLE group, with 6 mesial TLE, 1 lateral TLE, 1 mesial-lateral TLE. And 7 patients in TPE group. Age of seizure onset (P=0.548), duration of epilepsy (P=0.099), age of remote encephalitis (P=0.385), type of semiology (P=0.315) and lateralization of MR lesions (P=1.000), interictal FDG-PET hypometabalism (P=1.000) or intracranial implantation (P=0.619) were of no statistically difference between TLE group and TPE group. Surgery was performed in all patients. Better outcome was obtained in TLE group(5/8 class Ⅰ), and poor was in TPE group(3/7class Ⅰ).ConclusionMesial-TLE and temporal plus epilepsy were common types of pharmaco-resistant post-encephalitic TLE. There was no way to differentiate clinically, except by SEEG. Mesial-TLE had a better outcome after surgery, but temporal plus epilepsy did not.
