Changes in GABA-immunoreactive cell density during motor focal epilepsy induced by cobalt in the rat

Summary The distribution of GABA-immunoreactive cell bodies and terminals was studied using an anti-GABA serum during the development of chronic focal epilepsy induced by cobalt deposits onto the motor cortex of the rat. Cell counts of GABA-positive neurons were carried out in the epileptogenic area and correlated with the electrophysiological activity of the cobalt focus. In normal control rats, we identified GABA-immunoreactive somata and processes in the motor agranular cortex; they were multipolar or bipolar but never pyramidal and were present in all layers, especially in layer II. GABA-immunoreactive terminals were widely scattered in the neuropil and surrounded the unlabelled cell bodies. In the cobalt-treated animals, changes in the GABAergic innervation were observed during the development of the epileptic focus: decreases in the GABA-positive cell density and in the number of GABA-positive terminals were present before the onset of epileptic discharges and became more marked during the period of maximal spiking activity; a progressive return to normal values of GABA-positive cell density (except in the deep layers) as well as the reappearance of GABA positive terminals were associated with the extinction of the epileptic syndrome. Our observations suggest that the impaired inhibitory neurotransmission mediated by GABA plays a role in the development of the cobalt-induced epilepsy; moreover the recovery of GABAergic function which occurs during the extinction of the epileptic syndrome might imply a capacity for axonal regeneration of the GABAergic neurons.     

癫痫病人不对称性δ、θ活动的地形图研究

利用BEAM分析技术,以50例正常人为对照,用Z值概率差异地形图,对83例部分性与全面性发作的癫痫病人脑电背景活动的δ与θ不对称性情况进行分析,并与其它结果比较后显示,BEAM对癫痫病人的不对称性δ、θ的检出率达72％,较EEG目测分析敏感,其显示的病变区与EEG目测分析、CT、SPECT结果大多符合,可用作痫灶的定侧定位,亦有助于全面性癫痫与部分性癫痫的鉴别。     

西酞普兰对戊四氮点燃癫痫大鼠行为学及海马5-HT能递质系统影响的在体微透析研究

为研究5-羟色胺(5-HT)能神经递质在癫痫形成过程中的变化及西酞普兰(CTP)对其的影响,本研究用CTP(1mg/kg.d灌胃)预干预1周后,对戊四氮(PTZ,30mg/kg.d,腹腔注射)点燃癫痫过程中的行为学及在不同时间点对大鼠海马进行微透析取样,经高效液相电化学检测技术在活体观察了30只自由活动大鼠5-HT及其代谢产物5-羟吲哚乙酸(5-HIAA)水平和5-HT转化率(5-HIAA/5-HT)的动态变化。结果显示:PTZ注射后在CTP组发作潜伏期延长,发作程度轻和点燃时间延长,发作死亡率降低。点燃早期,CTP组大鼠的海马5-HT水平升高,5-HT转化率降低,与对照组和PTZ组比较,有显著性差异(P<0.05);点燃晚期CTP组和PTZ组与对照组比较5-HT水平和5-HT转化率均显著降低(P<0.05)。本研究结果提示PTZ点燃过程中,早期CTP升高脑内5-HT水平,可能直接抑制了引起爆发放电的动作电位,而抑制发作;晚期脑内5-HT神经元丢失和受体减少,功能减退,而导致CTP的作用减退。     

The effects of levetiracetam on objective and subjective sleep parameters in healthy volunteers and patients with partial epilepsy

Levetiracetam is a novel antiepileptic drug which has recently been released as an adjunctive treatment for partial epilepsy. In the two studies reported here we examined the objective and subjective effects of levetiracetam on sleep in 12 healthy volunteers and 17 patients [16 who could be evaluated for electroencephalogram (EEG) recordings] with a history of partial epilepsy on stable carbamazepine monotherapy. The studies were of a similar double-blind crossover placebo-controlled design with subjects' sleep being recorded in their own homes. The results from the two studies showed considerable similarities. In both, levetiracetam produced an increase in the time spent in stage 2 sleep, which in the patient study was accompanied by a decrease in the time spent in stage 4 sleep and in the volunteer study an increase in rapid eye movement (REM) latency. The subjective changes included reports that sleep was of a better quality with fewer awakenings and patients also reported that their sleep was more restful. Volunteers and patients did, however, feel less alert on waking in the morning. Therefore, both groups reported a decrease in awakenings after levetiracetam despite the finding from the EEG of no change in the actual number of awakenings. It may be concluded from both studies that levetiracetam does affect some indicators of subjective sleep perception, but does not influence objective sleep measures of sleep continuity. The results from the patient study during placebo add-on treatment also showed that patients on carbamazepine had a marked increase in SWS, an increase in stage 2 sleep and an increase in REM latency compared with healthy volunteers. Interestingly, levetiracetam also reduced bilateral epileptiform EEG activity, particularly in patients with more discharges.     

Effect of acoustic stimulation on GABAergic neurons in limbic structures of Krushinskii-Molodkina rats

Quantitative study of GABAergic and main cells in the hippocampus and piriform cortex of Krushinskii-Molodkina rats was performed 1 month after the incidence of seizure activity evoked by acoustic stimulation. The number of neurons significantly decreased in both regions and, particularly, in the hippocampus and central area of the piriform cortex. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 4, pp. 375–377, April, 2008     

局限性癫痫脑电时间序列的分形维数计算比较

为探索应用非线性动力学理论诊断癫痫病的新方法，对局限性癫痫病患者脑电时间序列进行了相关维数（Ｄｃ）和波形维数（Ｄｗ）的计算比较。观察到，痫性导联脑电的分形维数多低于对侧导联的值；相关维数Ｄｃ的相对变化量较波形维数Ｄｗ大；而波形维数Ｄｗ对痫性棘波敏感；结果提示，脑电时间序列的分形维数有可能成为诊断癫痫的特征参数，值得进一步深入研究。     

Identifying homologous anatomical landmarks on reconstructed magnetic resonance images of the human cerebral cortical surface

Guided by a review of the anatomical literature, 36 sulci on the human cerebral cortical surface were designated as homologous. These sulci were assessed for visibility on 3-dimensional images reconstructed from magnetic resonance imaging scans of the brains of 20 normal volunteers by 2 independent observers. Those sulci that were found to be reproducibly identifiable were used to define 24 landmarks around the cortical surface. The interobserver and intraobserver variabilities of measurement of the 24 landmarks were calculated. These reliably reproducible landmarks can be used for detailed morphometric analysis, and may prove helpful in the analysis of suspected cerebral cortical structured abnormalities in patients with such conditions as epilepsy.     

妊娠合并癫痫16例临床分析

目的探讨妊娠合并癫痫临床处理。方法回顾性分析16例妊娠合并癫痫孕妇服抗癫痫药情况、癫痫发作频率变化及妊娠结局。结果妊娠合并癫痫发生率0.078%,原发性4例,继发性12例。全身性癫痫发作13例（2例癫痫持续状态）,局部癫痫发作3例。孕期发作频率增加者5例,无变化者6例。孕期新发现单次发作5例。孕期未用抗癫痫药物（AEDs）3例,间断用药1例,连续用药7例,均为单一AEDs治疗。顺产4例,剖宫产10例,人工流产2例。新生儿出生无窒息,平均出生体重2852g,无新生儿出生缺陷,无新生儿死亡。母亲亦无产科并发症发生。2例人工流产孕妇癫痫持续状态、吸入性肺炎死亡,1例智力低下孕妇产后卡马西平中毒昏迷,抢救成功。结论妊娠可诱发并使癫痫发作频率增加。孕期用AEDs可控制癫痫发作。应采用单一AEDs治疗,且应按时监测血浆中AED及叶酸水平。     

颞叶癫痫的临床特点与脑电图分析

目的：分析颞叶癫痫患的临床特点及脑电图定位的意义。方法：回顾分析92例颞叶癫痫患的脑电图。结果：左颞有癫痫样波42例，右颞有癫痫样波29例，双颞有癫痫样波21例，临床表现与癫痫样波发放部位有关，癫痫波的传导主要有容积传导和神经传导方式。结论：结合患临床表现与脑电图癫痫样波起始部位分析有助于致痫灶的定位。