GABA Receptor Activity Suppresses the Transition from Inter-ictal to Ictal Epileptiform Discharges in Juvenile Mouse Hippocampus / 神经科学通报·英文版

Exploring the transition from inter-ictal to ictal epileptiform discharges (IDs) and how GABA receptor-mediated action affects the onset of IDs will enrich our understanding of epileptogenesis and epilepsy treatment. We used Mg-free artificial cerebrospinal fluid (ACSF) to induce epileptiform discharges in juvenile mouse hippocampal slices and used a micro-electrode array to record the discharges. After the slices were exposed to Mg-free ACSF for 10 min-20 min, synchronous recurrent seizure-like events were recorded across the slices, and each event evolved from inter-ictal epileptiform discharges (IIDs) to pre-ictal epileptiform discharges (PIDs), and then to IDs. During the transition from IIDs to PIDs, the duration of discharges increased and the inter-discharge interval decreased. After adding 3 μmol/L of the GABA receptor agonist muscimol, PIDs and IDs disappeared, and IIDs remained. Further, the application of 10 μmol/L muscimol abolished all the epileptiform discharges. When the GABA receptor antagonist bicuculline was applied at 10 μmol/L, IIDs and PIDs disappeared, and IDs remained at decreased intervals. These results indicated that there are dynamic changes in the hippocampal network preceding the onset of IDs, and GABA receptor activity suppresses the transition from IIDs to IDs in juvenile mouse hippocampus.

Effect of sodium valproate combined with phenytoin sodium on the epileptiform discharge and cognitive function in patients with refractory epilepsy / 新乡医学院学报

Objective To investigate the effect of sodium valproate combined with phenytoin sodium on the epileptiform discharge and cognitive function in patients with refractory epilepsy (RE).Methods A total of 213 patients with RE were selected from February 2011 to February 2015 in the Third Affiliated Hospital of Xinxiang Medical University.The patients were divided into phenytoin sodium group,sodium valproate group and combined treatment group according to the treatment methods,71 cases in each group.The patients in the phenytoin sodium group were treated with phenytoin sodium,the patients in the sodium valproate group were treated with sodium valproate,and the patients in the combined treatment group were treated with phenytoin sodium and sodium valproate.The electroencephalogram and cognitive function score of the patients in the three groups were performed before treatment and six months after treatment,and the therapeutic effect was evaluated.The improvement of electroencephalogram,cognitive function score and clinical effect were compared among the three groups.Results The total effective rate in the combined treatment group,phenytoin sodium group and sodium valproate group was 80.28％ (57/71),60.56％ (43/71) and 59.15％ (42/71) respectively,the total effective rate in the combined treatment group was significandy higher than that in the phenytoin sodium group and sodium valproate group (x2 =8.412,9.596;P ＜ 0.05),but there was no significant difference in the total effective rate between phenytoin sodium group and sodium valproate group (x2 =0.003,P ＞ 0.05).The improvement rate of electroencephalogram in the combined treatment group,phenytoin sodium group and sodium valproate group was 80.28％ (57/71),63.38％ (45/71) and 60.56％ (43/71) respectively,the improvement rate of electroencephalogram in the combined treatment group was significantly higher than that in the phenytoin sodium group and sodium valproate group(x2 =7.520,8.412;P ＜ 0.05),but there was no significant difference in the improvement rate of electroencephalogram between phenytoin sodium group and sodium valproate group (x2 =0.070,P ＞ 0.05).There was no significant difference in the scores of total intelligence quotient,language intelligence quotient and performance intelligence quotient in the three groups before treatment (P ＞ 0.05).The scores of total intelligence quotient,language intelligence quotient and performance intelligence quotient after treatment were significantly higher than those before treatment in the three groups (P ＜0.05).After treatment,the scores of total intelligence quotient,language intelligence quotient and performance intelligence quotient in the combined treatment group were significantly higher than those in the phenytoin sodium group and sodium valproate group(P ＞ 0.05);but there was no significant difference in the scores of total intelligence quotient,language intelligence quotient and performance intelligence quotient between the phenytoin sodium group and sodium valproate group (P ＞ 0.05).Conclusion Phenytoin sodium combined with sodium valproate can effectively control the epileptiform discharge,improve the cognitive function and improve the therapeutic effect in RE patients.

Effects of sleep epileptiform discharge on aural pre-attentive processing of children with benign childhood epilepsy with central-temporal spikes / 中华实用儿科临床杂志

Objective To explore the relationship between aural pre-attentive processing and non-rapid eye movement(NREM) sleep interictal epileptiform discharge (IED) in children with benign childhood epilepsy with central-temporal spikes (BECTS),in order to provide objective electrophysiological basis for early assessment of cognitive function lesion of BECTS children and intervention.Methods Twenty-nine children diagnosed as BECTS in the Second Affiliated Hospital of Xinxiang Medical University from February 2012 to November 2015 were selected,including 17 males and 12 females,and they were 4-14 years old with average age of (9.17 ±2.42) years,and the course of disease was 0.5-4.0 years.Twenty healthy children who had hospital routine check-up were selected as healthy control group,containing 14 males and 6 females,and they were 5-13 years old with average age of (8.55 ±3.09) years.Mismatch negativity (MMN) test was carried out in both groups,and the MMN amplitudes and latencies were analyzed.The long-term video electroencephalogram (VEEG) monitoring was conducted in the BECTS group to analyze the discharge phases (waking,sleep),locations and the IED indexes.The intergroup MMN indexes and the correlation between MMN and VEEG in the BECTS group were compared.Results The VEEG showed that the sleep structure of BECTS children did not change obviously.All children's epileptiform discharges were located in the Rolandic area,including 11 cases on the left side,8 cases on the right side,and 10 cases on both sides.Epilepsy discharge time:17 patients showed epileptiform discharges in sleep stages only and 12 patients showed epileptiform discharge in both sleep and waking stages.Epileptiform discharges of the 12 patients increased more significantly in sleep stage than thatin waking stage [(40.24 ± 25.15) times/min vs.(1.92 ± 1.38) times/rmin],and the difference was statistically significant (t =5.270,P =0.000).The sample IED index in stage 1 and 2 of NREM was (40.73 ± 10.69) times/min,in which 2 cases had IED indexes ＜ 5 times/min,the IED indexes of 3 cases ＞ 80 times/min who reached electrical status epilepticus during sleep,and others were 17.2-64.6 times/min.Clinical seizures in sleep stages were monitored in only 4 cases,which showed an electro-clinical segregation phenomenon from large quantities of sleep IED.The MMN amplitude was lower in the BECTS group than that in the healthy control group [(6.06 ± 1.89) μV vs.(7.28 ±1.64) μV],and the difference was statistically significant (t =2.346,P =0.025).Latency of BECTS group was longer than that in the healthy control group [(191.37 ±40.13) ms vs.(179.35 ±39.80) ms],but the difference was not statistically significant(t =1.037,P =0.355).Correlation analysis showed that the MMN amplitude was negatively related to discharge phases (r =-0.407,P ＜ 0.05) and the IED indexes (r =-0.644,P ＜ 0.01),and latency was positively related to the IED indexes (r =0.386,P ＜ 0.05),while the other VEEG indexes were not correlated with MMN.Conclusions The BECTS children have aural pre-attentive processing disturbance,especially unconscious automatic processing ability impairment,which weakenattention switch action of automatic processing switching to focused attention processing and fail to filter irrelevant information effectively.Sleep IED is an important factor in impairing the formation and reinforcement of acoustic discrimination and memory trace,interfering the acquisition,processing,storage and matching of new information,which induces children pre-attentive processing disturbance.The MMN may discover the electrophysiological changes of children pre-attentive processing disturbance in early stage.

Quantitative EEG Characteristics of Periodic Lateralized Epileptiform Discharges according to Benzodiazepine Responsiveness

BACKGROUND: Periodic lateralized epileptiform discharges (PLEDs) are associated with altered consciousness in 75% of patients. Major controversy about PLEDs is whether they are ictal or interictal phenomenon. Diagnosis of non-convulsive status epilepticus is often guided by response to benzodiazepine. We conducted a study to evaluate quantitative differences of EEG activity with PLEDs according to their response to acute benzodiazepine trial. METHODS: Nineteen patients with altered consciousness (stupor or coma) for whom the electroencephalography (EEG) recording with acute benzodiazepine trial was undertaken within 24 hours of onset of altered consciousness were retrospectively enrolled. Morphology of PLEDs including amplitude, frequency, and variability of the frequency was analyzed. Quantitative analysis of EEGs includes spectral power, spectral coherence, and graph theory analysis. Results of the analyses were compared between patients whose PLEDs were abolished by benzodiazepine (BDZ-R group) and those whose PLEDs persisted (BDZ-NR group). RESULTS: Morphologic variables were not different between two groups. In BDZ-R group, alpha-1 activity was increased in both frontopolar areas. Beta activity was also increased in both frontal areas while delta activity was reduced. In BDZ-R group, alpha-1 and beta activities were more coherent between bilateral hemispheres in frontal, anterior temporal, and central areas. Coherence line topographic map also revealed more bilaterally symmetric pattern in BDZ-R group. Network characteristics revealed by graph theory analysis did not differ between the two groups. CONCLUSIONS: Greater higher frequency activity (alpha-1 and beta) and lesser lower frequency activity (delta) in frontal areas, and more coherent activity in higher frequency band between hemispheres were associated with benzodiazepine responsiveness.

Clinical study of continuous video EEG monitoring in patients with acute cerebral infarction / 中国综合临床

Objective To investigate the effect of continuous video EEG monitoring on acute cerebral infarction comorbid epileptiform discharges and clinical seizures,and the relationship between cerebral infarction site and seizures.Methods Of the 337 patients continuously video EEG monitored in NICU at our department,259 were included for this study according to our inclusion and exclusion criteria.We recorded patients' epileptiform discharges,type and time of clinical onset,detailed CT and (or) MRI display,cerebral infarction site,and demographic data including admission age,gender,disease history and NIHSS score.Results There were 227/259 (88％) cases showed abnormal discharge in EEG,including 94 with side hemispheric slow wave,99 with local changes,34 with slow wave combined with epileptiform discharges.Early seizures was found in 12 cases,including 3 cases with seizure-induced cerebral infarction,9 cases with attack within one week after cerebral infarction.Ten in the 12 patients had tonic-clonic seizures,and the other 2 cases hadlocal seizures.Epileptiform discharges in EEG was found in 9 cases of the 12 patients.Clinical seizures were not observed in 25 patients with epileptiform discharges in EEG.Results on the relationship between cerebral infarction site and epileptiform discharges showed that incidence of epilepsy in patients with watershed infarction was significantly higher than other types of cerebral infarction (29.0％ vs 13.4％ and 9.0％,P =0.03,0.01 ).Conclusion Continuous video EEG monitoring is capable of detecting early epilepsy and epileptiform discharges.It can provide theoretical basis for the prevention and treatment of epilepsy.

Change of interictal epileptiform discharges after antiepiletic drug treatment in childhood epilepsy / 소아과

PURPOSE: Electroencephalography (EEG) findings can play a critical role in a variety of decisions, including initiation and withdrawal of antiepileptic drugs (AEDs) therapy. Interictal epileptiform discharges (IEDs) are predictor of recurrent seizures. We investigated IEDs in EEG after AED therapy and related factors in epileptic children. METHODS: The subjects were 257 children [151 males and 106 females; age, 6.79 (3.40) years; duration of therapy, 2.48 (1.85) years] diagnosed with epilepsy at the Department of Pediatrics, Pusan National University Hospital between January 2001 and December 2007, who received AEDs for more than 6 months. EEG was performed at the intervals of 6-12 months. We divided patients into 4 groups according to IED detection before and after AEDs treatment. Related clinical factors, including gender, age at the start of treatment, seizure type, cause of seizure, AED frequency, seizure control, duration of AED therapy, and background activity were investigated in the 4 groups. RESULTS: Generalized epilepsy was relatively frequen in patients who did not show IEDs in last follow-up EEG. There were no clinically significant differences according to gender, age at the start of treatment, cause of seizure, AED frequency, seizure control, duration of AED medication, and background activity in the 4 groups (P>0.05). CONCLUSION: IEDs changed after AED treatment in one-third of the patients. Generalized epilepsy is positive factor for negative IEDs in last follow-up EEG.

Effects of valproate sodium on phosphorylatted cAMP responsive element binding protein after hippocampal neuronal epileptiform discharge in rat / 重庆医科大学学报

Objective:To investigate the effects of valproate sodium on P-CREB1 after hippocampal neuronal epileptiform discharge in rat.Methods:The neonate wistar rats were decapitated quickly to obtain the hippocampal neuron,Which were cultured in vitro,After the epileptiform discharge model of neuron was established,neurons were divided into control group,model group,low valproate dose group(50mg/L) and high dose group(100mg/L).Expression positions of P-CREB1 after epileptiform discharge were examined by immunofluorescence technique,and Western blot was used to examine the expression intensity of P-CREB1 in different group.Results:Through immunofluorescence,P-CREB1 was observed in the nucleus of each group,and the most intensive expression was found in model group.Through western blot,the expression tendency was found to be the same as the former Results,Moreover,after added valproate sodium,the expression of P-CREB1 decreased,and there was statistical significance of the difference between low valproate dose and high dose(P

A Study of Epileptiform Discharges in Children with Chronic Recurrent Headaches / 대한소아신경학회지

PURPOSE: This study was undertaken to determine the incidence and the meaning of epileptiform discharges accompanied by chronic recurrent headaches. METHODS: We selected 449 cases of children who visited Dong-A University Hospital because of recurrent headaches from January 1999 to July 2005. The headaches were classified by the criteria established by the International Headache Research Committee in 2004. The electroencephalography was performed in 336 cases and 36 cases who showed epileptiform discharges were selected. We studied the characteristics of epileptiform discharges, MRI findings and the relationship with epilepsy. RESULTS: The incidence of interictal epileptiform discharges(ILEDs) of the patients with chronic headaches was 10.7%, which was higher than that in a normal population. In the location of ILEDs, focal areas(9.2%) were more common than general areas(1.5%). The incidence of the ILEDs was different according to the types of headaches(P<0.01). The focal ILEDs were concentrated at the central temporal areas. The most common type of ILEDs was frequent epileptiform discharges(63.9%). For the wave forms of ILEDs, focal spike activities were 83.3%, and bursts of slow waves mixed with spikes were 13.9%. Among the 36 cases that showed the ILEDs, 2 cases were associated with epilepsy and another 2 with AV malformation on the MRI images. CONCLUSION: The ILEDs of the patients with chronic recurrent headaches mainly occurred in the central temporal areas as focal spike wave forms, which shows a benign course. Because a few cases can accompany epilepsy and brain abnormalities, close observation and follow-up tests are needed.

Initial research of hippocampal neurons epileptiform discharge model in neonate rats / 重庆医科大学学报

Objective:To establish an ex-vivo epileptic model by investigating hippocampal neurons epileptiform discharge induced by magnesium-free extracellular fluid. Methods:Neonatal Wistar rats(

The Effect of Benzathine Penicillin-induced Focal Interictal Epileptiform Discharges on the Expression Patterns of c-JUN Protein in the Rat Brain

BACKGROUND: Immediate early gene (IEG) is supposed to be linked in the continuous seizure induced long-term changes of specific neurons. We tried to investigate the effects of focal interictal epileptiform discharges on the c-JUN expression in the rat brain which is not clearly understood. METHODS:Epidural electrodes were placed on a male Sprague-Dawley weighing 150~230 g and benzathine penicillin (Pc) was applied cortically. After focal interictal epileptiform discharges were successfully identified, EEG was recorded regularly. Cardiac perfusion and extraction of the brain was done at 2, 4, 24 hours and 1 week after the Pc application. Sixteen rats were evenly distributed into 4 groups. Immunocytochemical staining with specific antisera (Santa Cruz) was performed. RESULTS: The epileptiform discharges were induced within an hour after topical Pc applications. At 2 hours after Pc application, c-JUN was moderately expressed in the dentate gyrus (DG) and weakly expressed in the CA3 pyramidal cell, amygdala, pyriform cortex, thalamus, and neocortex. At 4 hours, c-JUN was minimally expressed in DG and other regions. Whereas, at 24 hours, c-JUN was maximally expressed in the DG and also in the CA3 pyramidal cell, amygdala, pyriform cortex, thalamus, and neocortex. One week after Pc application, c-JUN was moderately expressed in the DG and weakly expressed in the CA3 pyramidal cell, amygdala, pyriform cortex, and neocortex. CONCLUSIONS: This data showed that even focal interictal epileptic activity can induce IEG encoded c-JUN protein in the specific distant brain regions of a rat until a late period and the expression pattern showed a synchronous and bimodal pattern.

Lateralizing value of interictal epileptiform discharge in temporal lobe epilepsy

OBJECTIVE & BACKGROUND: There have been reports on the lateralizing value of temporal lobe interictal epileptiform discharge(IED), yet it is a matter of debate till now. We studied our patients focusing on the degree of lateralization by which accurate lateralization was possible and also on the significance of bisynchronous IED(BIED) in the lateralization of temporal lobe epilepsy. METHOD: Fifty two patients were included in the study who were diagnosed as having medial temporal lobe epilepsy through video-EEG monitoring and brain MRI. Twenty four hour sleep-deprived interictal scalp EEG was checked for all of them. After that, we counted the number of independent IED(IIED) and BIED originating from anterior temporal areas. Then we tried to find a reasonable degree of IED above which correct lateralization of epileptogenic area was possible by using brain MRI as a standard. We also tried to find a significance of BIED in the lateralization of temporal lobe epilepsy by comparing the result excluding patients with BIED to that includig patients with BIED. RESULT: Lateralization of IED was over 80% accurate if the cutoff point was set at 70% and patients with BIED were included, but nearly 100% accurate of the cutoff point was set at 80% and patients with BIED were excluded. CONCLUSION: Influence of BIED on the accuracy of lateralization by IED is significant, and if the lateralization of IED is over 80% in patients with no BIED, the chance of true lateralization is very high.

Clinical study on epileptiform discharge in children

No abstract available.