Typical absence seizures triggered by photosensitivity

PURPOSE: To describe the characteristics of patients with typical absence seizures (TASs), consistently triggered by photosensitivity. METHODS: Consecutive patients having TAS induced by intermittent photic stimulation were included in the study. All clinical parameters, EEG, and video-EEG data were assessed during the long-term follow-up. Statistical analyses were performed with SPSS 10.0 software. RESULTS: Nine female and two male patients with a mean age at onset of 14 +/- 5.9 years (range, 7-27 years) and with a mean follow-up of 9 +/- 7.56 years had photosensitive TASs. They constituted 7.64% of absence epilepsies and 0.4% of all patients seen in our tertiary center. The seizures were usually subtle and had a reported frequency of 1 to 9 times daily. Seven patients were clinically photosensitive and reported that some of their TASs were induced by photic stimuli in daily life. All patients also had spontaneous TASs, and four of them had generalized tonic-clonic seizures. EEG results did not show any distinctive features when compared with those of other cases with TASs. Remission could not be achieved in five patients with antiepileptic drug treatments, and we always observed relapses after drug discontinuation or dose reduction in the remaining six cases in remission. Spontaneous remission did not occur even in the five patients older than 30 years. CONCLUSIONS: TASs triggered by photosensitivity are a rare and heterogeneous clinical condition with a marked female preponderance. It is notable that TASs do not remit in these cases.     

Corticothalamic modulation during absence seizures in rats: a functional MRI assessment

PURPOSE: Functional magnetic resonance imaging (fMRI) was used to identify areas of brain activation during absence seizures in an awake animal model. METHODS: Blood-oxygenation-level-dependent (BOLD) fMRI in the brain was measured by using T2*-weighted echo planar imaging at 4.7 Tesla. BOLD imaging was performed before, during, and after absence seizure induction by using gamma-butyrolactone (GBL; 200 mg/kg, intraperitoneal). RESULTS: The corticothalamic circuitry, critical for spike-wave discharge (SWD) formation in absence seizure, showed robust BOLD signal changes after GBL administration, consistent with EEG recordings in the same animals. Predominantly positive BOLD changes occurred in the thalamus. Sensory and parietal cortices showed mixed positive and negative BOLD changes, whereas temporal and motor cortices showed only negative BOLD changes. CONCLUSIONS: With the BOLD fMRI technique, we demonstrated signal changes in brain areas that have been shown, with electrophysiology experiments, to be important for generating and maintaining the SWDs that characterize absence seizures. These results corroborate previous findings from lesion and electrophysiological experiments and show the technical feasibility of noninvasively imaging absence seizures in fully conscious rodents.     

Using recurrence plot for determinism analysis of EEG recordings in genetic absence epilepsy rats

OBJECTIVE: Understanding the transition of brain activity towards an absence seizure is a challenging task. In this paper, we use recurrence quantification analysis to indicate the deterministic dynamics of EEG series at the seizure-free, pre-seizure and seizure states in genetic absence epilepsy rats. METHODS: The determinism measure, DET, based on recurrence plot, was applied to analyse these three EEG datasets, each dataset containing 300 single-channel EEG epochs of 5-s duration. Then, statistical analysis of the DET values in each dataset was carried out to determine whether their distributions over the three groups were significantly different. Furthermore, a surrogate technique was applied to calculate the significance level of determinism measures in EEG recordings. RESULTS: The mean (+/-SD) DET of EEG was 0.177+/-0.045 in pre-seizure intervals. The DET values of pre-seizure EEG data are significantly higher than those of seizure-free intervals, 0.123+/-0.023, (P<0.01), but lower than those of seizure intervals, 0.392+/-0.110, (P<0.01). Using surrogate data methods, the significance of determinism in EEG epochs was present in 25 of 300 (8.3%), 181 of 300 (60.3%) and 289 of 300 (96.3%) in seizure-free, pre-seizure and seizure intervals, respectively. CONCLUSIONS: Results provide some first indications that EEG epochs during pre-seizure intervals exhibit a higher degree of determinism than seizure-free EEG epochs, but lower than those in seizure EEG epochs in absence epilepsy. SIGNIFICANCE: The proposed methods have the potential of detecting the transition between normal brain activity and the absence seizure state, thus opening up the possibility of intervention, whether electrical or pharmacological, to prevent the oncoming seizure.     

FMRI of brain activation in a genetic rat model of absence seizures

PURPOSE: EEG-triggered functional magnetic resonance imaging (fMRI) was used to identify areas of brain activation during spontaneous spike-and-wave discharges (SWDs) in an epileptic rat strain under awake conditions. METHODS: Spontaneous absence seizures from 10 WAG/Rij rats were imaged by using T2*-weighted echo planar imaging at 4.7 Tesla. fMRI of the blood-oxygenation-level-dependent (BOLD) signal was triggered based on EEG recordings during imaging. Images obtained during spontaneous SWDs were compared with baseline images. RESULTS: Significant positive BOLD signal changes were apparent in several areas of the cortex and several important nuclei of the thalamus. In addition, no negative BOLD signal was found in any brain area. CONCLUSIONS: We have shown that EEG-triggered BOLD fMRI can be used to detect cortical and thalamic activation related to the spontaneous SWDs that characterize absence seizures in awake WAG/Rij rats. These results draw an anatomic correlation between areas in which increased BOLD signal is found and those in which SWDs have been recorded. In addition, no negative BOLD signal was found to be associated with these spontaneous SWDs. We also demonstrated the technical feasibility of using EEG-triggered fMRI in a genetic rat model of absence seizure.     

fMRI of generalized absence status epilepticus in conscious marmoset monkeys reveals corticothalamic activation

PURPOSE: A nonhuman primate model of generalized absence status epilepticus was developed for use in functional magnetic resonance imaging (fMRI) experiments to elucidate the brain mechanisms underlying this disorder. METHODS: Adult male marmoset monkeys (Callithrix jacchus) were treated with gamma-butyrolactone (GBL) to induce prolonged absence seizures, and the resulting spike-wave discharges (SWDs) were analyzed to determine the similarity to the 3-Hz SWDs that characterize the disorder. In addition, blood-oxygenation-level-dependent (BOLD) fMRI was measured at 4.7 Tesla after absence seizure induction with GBL. RESULTS: Electroencephalographic recordings during imaging showed 3-Hz SWDs typical of human absence seizures. This synchronized EEG pattern started within 15 to 20 min of drug administration and persisted for >60 min. In addition, pretreatment with the antiepileptic drug, ethosuximide (ESM), blocked the behavioral and EEG changes caused by GBL. Changes in BOLD signal intensity in the thalamus and sensorimotor cortex correlated with the onset of 3-Hz SWDs. The change in BOLD signal intensity was bilateral but heterogeneous, affecting some brain areas more than others. No significant negative BOLD changes were seen. CONCLUSIONS: The BOLD fMRI data obtained in this marmoset monkey model of absence status epilepticus shows activation within the thalamus and cortex.     

Refractory absence epilepsy associated with GLUT-1 deficiency syndrome

GLUT-1 deficiency syndrome (GLUT-1 DS) is a disorder of cerebral glucose transport associated with early infantile epilepsy and microcephaly. We report two boys who presented with refractory absence epilepsy associated with hypoglycorrhachia, both of whom have genetically confirmed GLUT-1 DS. We propose that these children serve to expand the phenotype of GLUT-1 DS and suggest that this condition should be considered as a cause of refractory absence seizures in childhood.     

Brainstem triggers absence seizures in human generalized epilepsy

Simultaneous analysis of brainstem auditory evoked potentials (BAEPs) with reference to electroencephalography (EEG) was designed to examine the brainstem function corresponding to the EEG event. With this method, we investigated the brainstem function pre- and during the paroxysmal discharge in human absence seizures classified as primary generalized epilepsy (PGE). Two types of functional change in the lower brainstem were revealed as parameters of wave-III components (amplitude and area) of BAEPs without significant change in the upper brainstem. One was long-range biphasic fluctuation (acceleration followed by abrupt deceleration with the maximum -6.4+/-3.2 s before the seizure onset), and the other was rhythmic oscillation with 3 Hz. The latter, synchronized with the cortical spike-and-wave complex, imposed on the descending slope of the former. One important point is that both preceded the onset of cortical paroxysmal discharge. The results reappraise the classical hypothesis of "centrencephalic system" on seizure generating mechanism in human PGE. The results prove the primary triggering role of the lower brainstem that is independent of sleep-related synchronizations. The method is applicable to other types of EEG event for the investigation of brainstem involvement.     

An association analysis at 2q36 reveals a new candidate susceptibility gene for juvenile absence epilepsy and/or absence seizures associated with generalized tonic-clonic seizures

Purpose: To further evaluate the previously shown linkage of absence epilepsy (AE) to 2q36, both in human and WAG/Rij absence rat models, a 160‐kb region at 2q36 containing eight genes with expressions in the brain was targeted in a case–control association study involving 205 Turkish patients with AE and 219 controls. Methods: Haplotype block and case–control association analysis was carried out using HAPLOVIEW 4.0 and inhibin alpha subunit (INHA) gene analysis by DNA sequencing. Key Findings: An association was found between the G allele of rs7588807 located in the INHA gene and juvenile absence epilepsy (JAE) syndrome and patients having generalized tonic–clonic seizures (GTCS) with p‐values of 0.003 and 0.0002, respectively (uncorrected for multiple comparisons). DNA sequence analysis of the INHA gene in 110 JAE/GTCS patients revealed three point mutations with possible damaging effects on inhibin function in three patients and the presence of a common ACTC haplotype (H1) with a possible dominant protective role conferred by the T allele of rs7588807 with respective p‐values of 0.0005 and 0.0014. Significance: The preceding findings suggest that INHA could be a novel candidate susceptibility gene involved in the pathogenesis of JAE or AE associated with GTCS.     

难治性颞叶癫癎患者脑内KCNJ4基因表达的研究

目的观察内向整流钾离子通道亚单位基因KCNJ4 mRNA及其编码的蛋白产物Kir2.3在难治性颞叶癫癎患者和急性脑外伤患者脑内的表达差异,从分子水平探讨难治性颞叶癫癎可能的发病机制.方法 12例难治性颞叶癫癎患者手术切除的颞叶组织,10例急性脑外伤患者相应部位颞叶组织,利用逆转录-聚合酶链反应(RT-PCR)与蛋白印迹检测(Western-blot)方法检测两组间KCNJ4 mRNA(KCNJ4 mRNA/β-actin)与Kir2.3通道蛋白(Kir2.3/β-actin)的表达.结果难治性颞叶癫癎患者与脑外伤患者比较,颞叶组织KCNJ4 mRNA(0.438±0.178)及Kir2.3通道蛋白(0.063)的表达水平均降低,差异有统计学意义(P＜0.05).结论 KCNJ4 mRNA表达水平的下调及其编码产物Kir2.3通道蛋白表达水平的下降,可能是难治性颞叶癫癎发生发展的重要的分子学基础之一.     

mRNA blood expression patterns in new‐onset idiopathic pediatric epilepsy

Purpose: Determine if blood messenger RNA (mRNA) expression patterns in children with newly diagnosed untreated idiopathic epilepsy are different from those in healthy controls. Determine the differential expression patterns between epilepsy patients with generalized onset or partial onset seizures compared to healthy controls. Methods: Whole blood was obtained from otherwise healthy pediatric patients with newly diagnosed untreated idiopathic epilepsy along with healthy pediatric controls. mRNA was isolated and hybridized to Affymetrix HGU 133 2.0+ microarrays. Analysis was performed using Genespring. Differentially expressed gene lists resulted from comparison of (1) epilepsy and control groups and (2) seizure type subgroups with controls. Tissue expression and gene ontology analysis was performed using DAVID. Key Findings: Thirty‐seven epilepsy patients and 28 controls were included. Overall, 575 genes were differentially expressed in subjects with epilepsy compared to controls. The generalized seizure subgroup versus control (GvC) gene list and the partial seizure subgroup versus control (PvC) gene list were different (p < 0.05). Tissue expression analysis identified almost half of the genes in GvC and PvC as brain based. Functional group analysis identified several biologically relevant pathways. In GvC, these included mitochondria and lymphocyte activation. In PvC, we identified apoptosis, inflammatory defense, and cell motion pathways. Significance: A unique, biologically meaningful mRNA expression pattern is detectable in whole blood of pediatric subjects with new‐onset and untreated epilepsy. This analysis finds many similar pathways to those identified in brain studies examining lesional intractable epilepsy. Blood mRNA expression patterns show promise as a target for biomarker development in pediatric epilepsy.     

Eight years follow-up of a generalized epilepsy patient with eating-induced late-onset epileptic spasms and atypical absence with myoclonic jerks

PurposeEating epilepsy was previously known as a kind of focal reflex epilepsy. However, the development of eating-induced multiple generalized seizures and the associated EEG changes were rarely reported. Herein, we present a 13-year-old generalized epilepsy patient with eating-induced generalized seizures since the age of 5.Case presentationThe 13-year-old male patient had suffered from late-onset eating-induced epileptic spasms during the meal since the age of 5. Meanwhile, he also experienced spontaneous epileptic spasms during the period of sleep. The seizure frequency and type gradually increased from 7 years of age. In addition to epileptic spasms, he started experiencing atypical absence with myoclonic jerks during the meal. Ictal EEG presented as the appearance of an irregular slow-wave mixed with generalized polyspike wave with the intake of food, and gradually evolved to bursts of generalized polyspike wave complexes. At the end of the meal, the EEG returned to normal. Nevertheless, at the age of 13, his seizure frequency increased and appeared new seizure type, and besides epileptic spasm and atypical absence, he began to experience myoclonic seizure during sleep and awaking-generalized tonic-clonic seizure in the morning. In this period he started taking valproic acid, topiramate and clonazepam, and his seizure frequency was reduced.ConclusionIn conclusion, this case demonstrated the variability of eating induced multiple generalized seizure types, and eight years follow-up also indicates that generalized epilepsy progressed with age. The EEG and clinical changes of our patient contribute to a better understanding of the electro-clinical features of eating-induced multiple generalized seizures and the course of generalized epilepsy with such seizures.     

A duplication in 1q21.3 in a family with early onset and childhood absence epilepsy

Early onset absence epilepsy (EOAE) starting before the age of 4 years constitutes a rare subgroup of the idiopathic generalized epilepsies (IGEs). A strong genetic component in IGE has been suggested by twin and family studies. We describe a boy with absence seizures starting at the age of 9 months whose parents both had childhood absence epilepsy. A 192-kb duplication in 1q21.3 was identified in the proband and his father, encompassing the gene CHRNB2 coding for the β-2 subunit of the nicotinic acetylcholine receptor and the gene ADAR coding for adenosine deaminase, an enzyme responsible for RNA editing. Both are candidate genes for seizure disorders. The duplication was not identified in 191 independent IGE patients (93 EOAE; 98 classical IGE) or in 1,157 population controls.     

Effect of corticosteroids in a twin child with idiopathic localization-related epilepsy

Corticosteroids have been used only in the treatment of special epileptic syndromes or epileptic encephalopathies, such as infantile spasms. We report an antiepileptic effect of corticosteroids that were used for treatment of nephropathy in a monozygotic twin child with idiopathic localization-related epilepsy (I-LRE). The patient and her monozygotic twin sister exhibited repeated partial seizures at two years of age and electroencephalogram (EEG) showed focal spikes in the occipital area and, on other occasions, the centro-parietal areas. After oral antiepileptic drugs were started, the twins still exhibited occasional seizures. The patient had IgA nephropathy at four years of age and intravenous methylprednisolone and oral prednisolone were administered. Her seizures and epileptiform discharges on EEG disappeared, while her sister continued to have seizures and EEG abnormalities. When the dose of oral predonisone was reduced, the seizures relapsed and EEG again revealed focal spikes. We conclude that corticosteroids exhibit efficacy towards seizures and epileptiform discharges on EEG in patients with I-LRE without epileptic encephalopathies.     

Gene expression analysis of HUVEC in response to TF-binding

Introduction

Tissue factor (TF), the cofactor for factor VII/VIIa (FVII/FVIIa) and initiator of the extrinsic pathway, is transiently expressed on intravascular cells under control of cytokines and growth factors. In addition, endothelial cells express a binding site for external TF. In the present study, we investigated gene expression of endothelial cells derived from human umbilical veins (HUVEC) in response to TF-binding to identify differentially expressed genes.

Materials and methods

HUVEC were treated with recombinant relipidated TF (Innovin) versus nontreated cells, as well as TF/FVIIa versus FVIIa alone. TF binding was measured by ELISA. Gene expression profiles were examined using HG-U133 plus 2.0 arrays (Affymetrix).

Results

Gene expression analysis of HUVEC showed 148 up-regulated and 29 down-regulated genes 4 h after TF binding. Notably, the genes, which were significantly up- and down-regulated, either by TF alone or by the complex of TF/FVIIa, exhibited a complete overlap, indicating that activation of endothelial cells after binding of external added TF does not depend on FVIIa as has been demonstrated for TF-expressing cells. TF-mediated regulation of gene expression of several genes, involved in regulation of apoptosis, cell adhesion, cell motility, and angiogenesis, was confirmed by qPCR. Furthermore, in case of SELE, TGFB2, TNFAIP3, TNFSF4, TNFSF18, TAGLN, CXCL1, PCF11 antibodies directed to TF clearly inhibited TF-mediated regulation of gene expression.

Conclusions

The results demonstrate that interaction of TF with HUVEC via a binding site, independent from FVIIa, may result in regulation of a variety of genes involved in arteriosclerosis, cancer, and cardiovascular diseases.     

Analyzing the etiology of benign rolandic epilepsy: a multicenter twin collaboration

PURPOSE: Benign rolandic epilepsy (BRE) is considered a genetically determined idiopathic partial epilepsy. We analyzed a large sample of twins from four international twin registers to probe the genetics of BRE. We also aim to synthesize the apparently conflicting family and twin data into a model of BRE etiology. METHODS: Large population-based twin registries of epilepsies from Odense (Denmark), Richmond, Virginia (United States), and Oslo (Norway) were reviewed for BRE cases and added to our Australian twin data. Diagnosis of classic BRE was based on electroclinical criteria with normal neurologic development. Cases with a compatible electroclinical picture but abnormal neurologic development were termed non-classic BRE. RESULTS: Eighteen twin pairs were identified (10 monozygous; eight dizygous) of whom at least one twin was diagnosed with classic BRE among a total sample of 1,952 twin pairs validated for seizures, and all were discordant for BRE. The estimated monozygous pairwise concordance for BRE in this sample was 0.0 [95% confidence interval (CI), 0.0-0.3). Four twin pairs (one monozygous, three dizygous) had non-classic BRE, and all co-twins had seizures. CONCLUSIONS: The twin data showing an absence of any concordant twin pairs with classic BRE suggest that noninherited factors are of major importance in BRE. Modelling the data shows that the familial occurrence of centrotemporal spikes makes only a minor contribution to the familial aggregation of BRE. Genetic factors are probably more important in non-classic BRE. The etiology and mode(s) of inheritance of BRE are much more complicated than initially conceptualized.     

Eyelid Myoclonia with Absences in Adults: A Clinical and Video-EEG Study

Summary: We report clinical and video-EEG findings in 11 adults with the syndrome of eyelid myoclonia with absences (EMA). Prevalence was 2.7% among all epilepsies and 12.9% among idiopathic generalized epilepsies (IGE) with typical absences. All patients with EMA were women, with a mean age of 30.9 years and a mean age of 7.8 years at reported onset of eyelid myoclonia. The characteristic seizures, studied with video-EEG in 10 patients, began with and were mainly manifested by eyelid myoclonia, either alone if brief ( 2 s) or with associated mild impairment of consciousness if longer. The ictal EEG was characterized by polyspike and slow waves at 3-6 Hz. Ictal clinical and EEG manifestations occurred mainly after eye closure and were inhibited by total darkness. All patients were photosensitive, but photosensitivity decreased with age; nonpatient had self-induced seizures. Infrequent generalized tonic-clonic seizures (GTCS) occurred in all but the youngest patient; they were usually infrequent and were precipitated mainly by flickering lights, sleep deprivation, fatigue, and menstruation. Mild myoclonic jerks of the upper limbs occurred in 6 patients. Eyelid myoclonia was resistant to medication and persisted despite control of other seizures.     

Genetic absence epilepsy rats from Strasbourg have increased corticothalamic expression of stargazin

Stargazin is membrane bound protein involved in trafficking, synapse anchoring and biophysical modulation of AMPA receptors. A quantitative trait locus in chromosome 7 containing the stargazin gene has been identified as controlling the frequency and duration of absence seizures in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS). Furthermore, mutations in this gene result in the Stargazer mouse that displays an absence epilepsy phenotype. GAERS stargazin mRNA expression is increased 1.8 fold in the somatosensory cortex and by 1.3 fold in the thalamus. The changes were present before and after the onset of absence seizures indicating that increases are not a secondary consequence of the seizures. Stargazin protein expression was also significantly increased in the somatosensory cortex after the onset of spontaneous seizures. The results are of significant importance beyond the GAERS model, as they are the first to show that an increase in stargazin expression may be pro-epileptic.     

老年癫(癎)55例临床分析

目的 探讨老年癫(癎)的临床特征. 方法 回顾性分析55例老年癫(癎)患者的临床表现、脑电图、头部影像学和治疗效果等临床资料.结果 55例老年癫(癎)患者中,全身性强直-阵挛发作30例(54.55%),部分性发作23例(41.82%);有脑血管病者34例(61.82%),脑萎缩4例(7.27%),药物不良反应4例(7.27%),脑肿瘤4例(7.27%).18例尸检结果: 8例为脑梗死,4例为脑软化灶(出血后),4例为吸入性肺炎,1例为肿瘤多发脑转移,1例为脑血管粥样硬化(管腔狭窄Ⅱ～Ⅲ级). 结论 老年癫(癎)患者病因中以脑血管病最为常见,其次为脑肿瘤、脑萎缩及药物中毒等.