匹罗卡品致痫大鼠海马calpain活性变化和其对神经元死亡的影响

目的探讨在匹罗卡品致痫的癫痫持续状态（SE）大鼠模型中,钙蛋白酶在大鼠海马组织中的活性,及钙蛋白酶对神经元坏死、凋亡产生的影响。方法雄性成年wistar大鼠,应用匹罗卡品致痫产生SE后60min后终止发作,24h后取材,行HE染色及tunel染色,观察海马神经元的坏死及凋亡情况,以及western blot检测钙蛋白酶1（μ-calpain）的活性。结果癫痫持续状态后24h,海马组织HE染色神经元数量减少,tunel阳性细胞数增加,钙蛋白酶1出现76ku条带。结论大鼠癫痫持续状态后24h,钙蛋白酶1在海马组织神经元活性增加,海马神经元出现坏死及凋亡。钙蛋白酶1与神经元的死亡存在着正相关。     

己酮可可碱预处理对癫痫发作大鼠海马损伤的影响

目的观察己酮可可碱(Ptx)预处理对癫痫发作大鼠海马损伤的影响。方法健康、成年雄性Wistar大鼠分为3组:对照组、癫痫组和Ptx预处理组。对照组腹腔注射生理盐水(127mg·kg~(-1));癫痫组和Ptx组大鼠用氯化锂-匹罗卡品(Li-Pc)诱发癫痫发作,先腹腔注射氯化锂(127mg·kg~(-1)),20h后背部皮下注射匹罗卡品(15mg·kg~(-1));Ptx组大鼠在匹罗卡品注射前30min通过腹腔给予Ptx(60mg·kg~(-1))。观察大鼠癫痫发作情况,利用Timm和Thionin染色分别观察海马苔藓纤维发芽(MSF)和神经元损伤情况。结果癫痫组大鼠在海马苔藓纤维发芽明显增多,并伴有海马神经元的损伤和脱失,Ptx预处理降低了Li-Pc诱发大鼠的癫痫发作率和癫痫发作程度,延长了其癫痫发作潜伏期,减轻了Li-Pc诱发大鼠海马的苔藓纤维出芽及神经元的损伤。结论 Ptx预处理缓解了Li-Pc诱发大鼠的癫痫发作和海马损伤,可能成为治疗癫痫的一种方法。     

TLR4、MRP8在内侧颞叶癫痫幼大鼠海马中表达的动态变化

目的观察氯化锂-匹罗卡品致痫幼大鼠各期海马中Toll-样受体4(TLR4)、髓样相关蛋白8(MRP8)表达的变化,探讨其是否与内侧颞叶癫痫(MTLE)发生有关。方法 21d SD雄性大鼠90只,随机分对照组(30只)和模型组(60只),腹腔注射氯化锂。17～18h后模型组腹腔注射匹罗卡品诱导癫痫持续状态(SE);对照组予等量生理盐水取代匹罗卡品腹腔注射。按自发发作出现和稳定时间(自发痫性发作在致痫后约3w出现,8w趋稳定),对照组和模型组随机分6个亚组:急性模型组(SE后2h)、潜伏模型组(SE后3w)、慢性自发发作组(SE后8w)及相对应时间点对照组。每亚组动物10只。免疫组化、免疫印迹、RT-PCR技术测定各亚组幼大鼠海马内TLR4、MRP8的表达。结果 TLR4、MRP8在模型组海马内表达明显增多,以CA3、CA1、DG区显著;与对照组相比,差异有显著性(P0.05)。模型亚组内,TLR4、MRP8在急性期和慢性期表达明显增高,而潜伏期无明显表达变化;3组比较差异有显著性(P0.05)。结论大鼠海马内TLR4、MRP8表达增多可能与MTLE发生有关。探讨其机制可能为MTLE的治疗提供新的靶点。     

Nectin-1在锂-匹罗卡品癫痫大鼠海马中的表达

目的为探讨Nectin-1在癫痫形成中的作用,我们采用经典的氯化锂-匹罗卡品大鼠癫痫模型,在点燃持续状态后不同时间点观察Nectin-1蛋白在大鼠脑海马的表达变化规律。方法①选用正常成年雄性SD大鼠,随机分为正常对照组(n=10)与模型组(n=50),模型组采用氯化锂-匹罗卡品腹腔注射法,对照组用等量生理盐水腹腔注射。成功点燃后存活的大鼠以(3 d、1周、2周、4周、6周)为研究时间点随机分为5个亚组,每组10只。②用Western-blot、免疫组化等经典方法观察Nectin-1蛋白在癫痫大鼠模型中的表达变化及规律。结果实验组大鼠腹腔注射匹罗卡品后,经过急性发作期及潜伏期、慢性期,出现癫痫反复的自发性发作,对照组未见急性及慢性发作。免疫组化染色对照组Nectin-1蛋白主要在胞膜及胞浆表达,在海马CA3区深染区域集中于透明层(SL)。癫痫组2周、4周时Nectin-1在齿状回有较多的阳性细胞,主要表现为胞浆和核膜棕色,并向内分子层分布。Western-blot与对照组相比,在匹罗卡品诱导的SE之后2周表达升高,一直持续到慢性期4周、6周。结论Nectin-1蛋白在癫痫大鼠模型SE后慢性期海马组织中表达较正常增高,可能与癫痫的形成机制有关。     

经鼻给予TGFβ1对癫痫持续状态大鼠海马神经元的保护作用

目的探讨经鼻腔给予TGFβ1(transforming growth factor beta1,TGFβ1)对氯化锂-匹罗卡品所致癫痫持续状态(status epilepticus,SE)大鼠海马神经元的保护作用及其潜在的机制。方法健康雄性SD大鼠60只,随机分为转化生长因子(TGF)组、匹罗卡品(Pilo)组和正常对照组(control)。建立氯化锂-匹罗卡品癫痫持续状态模型。应用TUNEL染色、Fluoro-Jade B(FJB)荧光染色法分别观察各组大鼠海马神经元的原位凋亡及变性死亡情况。采用免疫组化方法检测凋亡相关基因caspase-3的蛋白表达。结果 SE后24h、48h、72h,TGF组大鼠海马FJB、TUNEL、caspase-3阳性细胞均较Pilo组显著减少(P<0.05);72h最为明显(P<0.01)。结论经鼻(IN)给予TGFβ1可以显著抑制或减轻癫痫持续状态大鼠海马神经元的变性与凋亡,从而发挥神经保护作用。其潜在的神经保护机制可能涉及下调caspase-3蛋白表达。     

杏仁核电点燃癫(痫)模型与氯化锂-匹罗卡品大鼠癫(痫)模型的对比研究

目的:探讨不同类型癫(痫)大鼠在急性期和慢性期反复自发性发作时、发作前后脑电图(EEG)相应指标改变以及行为学改变.方法:选取雄性SD大鼠40只,随机分为A、B、C、D4组.A组10只为杏仁核电点燃癫(痫)模型(不作电刺激)对照组;B组:10只,为制作杏仁核电刺激点燃癫(痫)模型组;C组:10只,氯化锂-匹罗卡品癫(痫)模型(只注生理盐水)对照组;D组:10只,制作氯化锂-匹罗卡品癫(痫)模型组.结果:D组慢性期发作时EEG频率与急性期频率相比差异有统计学意义(P＜0.05),与B组各时期相比差异有统计学意义(P＜0.05);D组慢性期发作后3 min发作频率与B组急性期相比差异有统计学意义(P＜0.05);A组与C组在频率、波幅方面比较差异无统计学意义(P＞0.05).结论:B、D两种不同类型的癫(痫)大鼠不同时期EEG和行为学都会发生相应的改变.     

TLR9、MyD88在颞叶癫痫大鼠海马组织中表达的动态变化

目的观察氯化锂-匹罗卡品致痫大鼠各期海马中Toll-样受体9(TLR9)、髓样分化因子(MyD88)表达的变化,探讨其是否与颞叶癫痫发生有关。方法 SD雄性大鼠120只,随机分为对照组(30只)和模型组(90只),腹腔注射氯化锂。18 h~20 h后模型组腹腔注射匹罗卡品诱导癫痫持续状态(SE);对照组予等量生理盐水取代匹罗卡品腹腔注射。对照组和造模成功的模型组依据腹腔注射后时间随机分为10个亚组:急性模型组(SE后3 h、6 h、9 h、12 h、1 d、3 d、7 d);潜伏模型组(SE后14 d、28 d);慢自发发作组(SE后56 d)。每亚组动物模型组9只,对照组3只。免疫组化、蛋白印迹、RT-PCR技术测定各亚组癫痫大鼠海马内TLR9、MyD88的表达。结果TLR9、MyD88在模型组海马内表达明显增多,与对照组相比,差异有显著性(P0.05)。模型亚组内,TLR9、MyD88在急性期和慢性期表达明显增高,而潜伏期无明显表达变化。其中急性期内的增高多集中在癫痫发作后6 h;3组比较差异有显著性(P0.05)。结论大鼠海马内TLR9、MyD88表达增多可能与颞叶癫痫发病有关,探讨其机制可能为颞叶癫痫的治疗提供新的靶点。     

MicroRNA-132拮抗剂两种不同注射方式在匹罗卡品诱导的幼年大鼠癫痫急性期的差异

目的探讨microRNA-132拮抗剂对氯化锂-匹罗卡品诱导的幼年SD大鼠内侧颞叶癫痫(mesial temporal lobe epilepsy,MTLE)模型急性期的影响。方法实验分为4组:microRNA-132拮抗剂侧脑室置管组;microRNA-132拮抗剂阴性对照置管组;microRNA-132拮抗剂直接注射组;microRNA-132拮抗剂阴性对照直接侧脑室注射组;实验各组药物干预在造模前24 h进行。利用氯化锂-匹罗卡品建立SD大鼠MTLE模型,通过行为学观察各组大鼠癫痫持续状态发作潜伏时长,Racine评分观察各组大鼠抽搐发作的严重程度,脑电图监测癫痫样放电的频率及波幅,并统计实验各组大鼠诱导SE的成功率及24 h后的死亡率。结果在实验各组中,建模成功率无显著性差异,microRNA-132拮抗剂直接注射组幼年SD大鼠造模以后达到SE的潜伏时较其阴性对照组明显延长、癫痫发作的Racine评分明显下降、脑电图结果显示痫样放电的幅度及频率显著下降,死亡率降低,结果有统计学意义(P0.05)。MicroRNA-132拮抗剂侧脑室置管注射组与microRNA-132拮抗剂侧脑室直接注射组结果无统计学差异(P0.05)。结论 microRNA-132拮抗剂预处理SD大鼠能明显延长氯化锂-匹罗卡品诱导的SD幼年大鼠癫痫发作的潜伏期,减轻急性期抽搐严重程度及大脑样痫放电,降低大鼠癫痫持续状态后的死亡率。提示microRNA-132拮抗剂对氯化锂-匹罗卡品诱导的幼年SD大鼠MTLE的发生具有抑制作用,抑制microRNA-132有可能成为癫痫持续状态药物治疗的潜在靶点和新方向。     

氯化锂-匹罗卡品致痫幼鼠海马结构损伤的形态学及苔藓纤维发芽研究

目的 观察幼鼠致痫后海马的组织病理学改变。方法 采用氯化锂－匹罗卡品腹腔注射制成幼鼠癫痫持续状态模型，应用常规病理及电镜观察海马结构的形态学改变，同时应用Timm组织化学染色方法进行苔藓纤维发芽的研究。结果 海马区神经元可见变性、坏死改变，以CA1区、CA3区为重。Timm染色见齿状回内分子层和CA3区下锥体层苔藓纤维发芽增加。结论 （1）氯化锂－匹罗卡品诱导的幼鼠癫痫持续状态可造成海马区神经元损伤；（2）幼鼠癫痫持续状态后海马CA1、CA3区神经元损伤较重；（3）幼鼠癫痫持续状态后可致苔藓纤维发增加。     

N-myc在大鼠急性痫性发作模型中的表达及其意义

目的 探讨在氯化锂-匹罗卡品诱导大鼠急性痫性发作模型中N-myc表达及其意义。方法健康Wistar雄性大鼠45只，随机分为生理盐水对照组、地西泮干预组和致痫1h～9d组(根据致痫后的不同时点分7个组)，共9组，每组5只。采用氯化锂-匹罗卡品联合腹腔注射急性致痫大鼠模型，常规脏染色观察实验大鼠脑组织的形态学改变，免疫组化染色法观察脑内N—myc表达产物分布及其含量变化。结果 致痫1d～9d组尤其致痫6d和9d两组可见到脑组织损伤性改变，海马区重于皮质区。生理盐水对照组N—myc几乎无表达，地西泮干预组低表达，致痫组表达增多，尤其以致痫1d组和致痫3d组最为明显。结论 急性痫性发作或癫痫持续状态可导致脑组织损伤性改变，以海马结构等易损区为明显。N—myc表达及其表达量可能与急性痫性发作后脑损伤及其受累部位有关。     

Afebrile seizures associated with minor infections: comparison with febrile seizures and unprovoked seizures

This study aimed to demonstrate that afebrile seizures provoked by minor infections constitute a distinct epilepsy syndrome different from febrile seizures and unprovoked afebrile seizures. Of the children who were admitted to hospitals for their first seizure, 1170 had febrile seizures, 286 had provoked seizures, and 125 had unprovoked afebrile seizures. Children with provoked seizures were afebrile at the time of seizure but manifested definite symptoms or signs of minor infection, for example, cough, coryza, vomiting or diarrhea, normal metabolic and cerebrospinal fluid investigations, and no obvious cause for their seizures. The average follow-up was 6.1 years. The Kaplan-Meier estimate of risk at 5 years for subsequent unprovoked afebrile seizures after a first febrile seizure, provoked seizure, or unprovoked afebrile seizure was 1.6%, 5.7%, and 65.7% respectively. All differences were statistically significant (P < 0.0014). In conclusion, afebrile seizures provoked by minor illnesses constitute a distinct type of situation-related seizures, which have not been previously described. Children with provoked seizures have a much lower risk of subsequent unprovoked afebrile seizures than patients with the first afebrile seizure. Careful inquiry for symptoms of minor infections when children present with their first afebrile seizure will help determine the risk for subsequent seizures and the need for antiepileptic drugs.     

Prevalence of alexithymia in patients with psychogenic non-epileptic seizures and epileptic seizures and predictors in psychogenic non-epileptic seizures

ObjectiveThe first objective of this study was to determine the prevalence rate of alexithymia (dysregulation and unawareness of emotion) in patients with psychogenic non-epileptic seizures (PNESs) and epileptic seizures (ESs). The second objective was to identify the predictors of alexithymia in patients with PNESs.MethodsWe studied 66 consecutive patients with PNESs and 35 patients with ESs with the Toronto Alexithymia Scale-20. The prevalence of alexithymia was determined in both groups. In order to identify the risk factors of alexithymia in PNES, the Trauma Symptom Inventory-II (TSI-II), the MMPI 2-RF, a clinical history, and demographic variables were studied.ResultsOur study revealed a prevalence of alexithymia in PNES and ES of 36.9% and 28.6%, respectively (not a significant difference). Upon examining the group with PNES, we found a significant correlation between alexithymia and Anxious Arousal (r = .497, p < .000), Intrusive Experiences (r = .541, p < .000), Dissociation (r = .421, p < .001), and Defensive Avoidance (r = .444, p < .000) from the TSI-II. Minnesota Multiphasic Personality Inventory-2-RF RCd (r = .512, p < .000), RC1 (r = .346, p < .017), RC2 (r = .355, p < .017), RC3 (r = .467, p < .001), and EID (r = .567, p < .000) also correlated significantly with alexithymia. However, stepwise regression analysis only retained Intrusive Experiences and Defensive Avoidance from the TSI-II and the cynicism RC3 scale from the MMPI 2-RF.ConclusionSymptoms of psychological trauma and cynicism in patients diagnosed with PNESs were associated with alexithymia. These findings are encouraging, as they assist in better understanding the condition and in treatment design for this subset of patients.     

Fibromyalgia and seizures

The purpose of this case‐matched study was to determine how frequently fibromyalgia is associated with different paroxysmal neurological disorders and explore the utility of fibromyalgia as a predictor for the diagnosis of psychogenic non‐epileptic seizures. The billing diagnosis codes of 1,730 new, non‐selected patient encounters were reviewed over a three‐year period for an epileptologist in a neurology clinic to identify all patients with historical diagnoses of fibromyalgia. The frequency with which epileptic seizures, psychogenic non‐epileptic seizures, and physiological non‐epileptic events were comorbid with fibromyalgia was assessed. Age and gender case‐matched controls were used for a between‐group comparison. Wilcoxon tests were used to analyse interval data, and Chi‐square was used to analyse categorical data (p<0.05). Fibromyalgia was retrospectively identified in 95/1,730 (5.5%) patients in this cohort. Females represented 95% of the fibromyalgia sample (age: 53 years; 95% CI: 57, 51). Forty‐three percent of those with fibromyalgia had a non‐paroxysmal, neurological primary clinical diagnosis, most commonly chronic pain. Paroxysmal events were present in 57% of fibromyalgia patients and 54% of case‐matched controls. Among patients with fibromyalgia and paroxysmal disorders, 11% had epileptic seizures, 74% had psychogenic non‐epileptic seizures, and 15% had physiological non‐epileptic events, compared to case‐matched controls with 37% epileptic seizures, 51% psychogenic non‐epileptic events, and 12% physiological non‐epileptic events (p = 0.009). Fibromyalgia was shown to be a predictor for the diagnosis of psychogenic non‐epileptic seizures in patients with undifferentiated paroxysmal spells. However, our results suggest that the specificity and sensitivity of fibromyalgia as a marker for psychogenic non‐epileptic seizures in a mixed general neurological population of patients is less than previously described.     

Clozapine and seizures

Clozapine is a newly released antipsychotic that is associated with a higher prevalence of seizures than traditional neuroleptics. The authors describe four patients who developed seizure activity during clozapine treatment and provide recommendations for clinical management of this problem.     

Ondansetron and seizures

Experimental studies suggest that 5‐hydroxytryptamine (5‐HT) receptors play a role in epileptogenesis and seizure propagation. Ondansetron, a 5‐HT₃ receptor antagonist, has been reported to have proconvulsant and anticonvulsant effects in animals. We describe three patients who developed seizures after receiving ondansetron. There were two females and one male. Ages ranged from 38–56 years. None had a previous or family history of seizures. Four milligrams (mg) of ondansetron was given intravenously for severe nausea and vomiting in association with migraine, gastritis, and diabetic ketoacidosis. A generalized tonic–clonic seizure occurred in each patient—12, 15, and 22 min after injection. Brain magnetic resonance imaging (MRI) and electroencephalography (EEG) were normal in all patients. Although no antiepileptic drugs were given, none had seizure recurrence subsequently. The temporal relationship between ondansetron administration and seizures, lack of EEG or MRI abnormalities, and absence of seizure recurrence suggest that the seizures were causally related to ondansetron in our patients.     

Syncope and seizures

Abstract. Syncope and seizures are common conditions and pose diagnostic challenges for the clinician. The cumulative lifetime incidence of epilepsy is 3%, and the incidence of a first attack of syncope is 6.2 per 1000 person-years in the general population. Although the underlying pathophysiological processes are distinct, seizures and syncope share some clinical characteristics which may lead to diagnostic confusion. Confounding matters further is the fact that seizures and syncope may coexist in a given patient. For example, some conditions such as prolonged QT syndrome may result in both arrhythmia-associated syncope and seizures, and in some cases, seizures may result in cardiac arrhythmia and syncope. The clinical history, examination, electrocardiography, and combined EEG/ECG telemetry are all helpful in the diagnosis of seizures and syncope.     

Neuropeptides and seizures

There are four lines of evidence for or against a role of neuropeptides in epilepsy: Administration of a variety of opiate agonists into the ventricles or brain of animals produces a constellation of electrical and behavioral changes, seemingly receptor-specific, both sensitive to the specific opiate antagonist naloxone as well as certain anticonvulsant drugs. The primary reservation concerning these data in terms of their relevance to epilepsy regards the fact that the peptides are exogenously administered in relatively high doses. Hence, these data may reflect neurotoxic effects of peptides rather than physiologic function. A variety of opiate agonists are anticonvulsant and naloxone shortens the postictal state in some experimental seizure models. One could attempt to reconcile these data with those in No. 1 by hypothesizing that the spikes and behavioral changes examined in the latter experimental parodynes represented a sort of isolated model of the postictal state. Naloxone has little effect in clinical epilepsy. These data are far from conclusive for two reasons. First, few patients have been studied. Second, because of the issue of opiate receptor heterogeneity and the high doses of naloxone needed experimentally to block non-mu opiate effects, the doses of naloxone used clinically to date are too low to rule out possible delta- or epsilon-mediated effects. The negative clinical data are illustrative of the dangers and difficulties of extrapolating data generated in animal models of seizures to the human condition. ACTH, a peptide that is derived from the same precursor molecule as beta-endorphin, is clearly an effective anticonvulsant in certain childhood seizure states. However, whether this is due to a direct or indirect (that is, cortisol) effect on brain is far from clear. Paradoxically, in contradistinction to other data concerning pro- and anticonvulsant properties of various opioid peptides, there is no animal model of infantile spasms to help resolve this important question.