胰岛素瘤：附21例报告

目的探讨胰岛素瘤的术前定位方法与术中决策。方法对１９８２～１９９８年外科治疗的２１例胰岛素瘤进行回顾性分析。结果全组２１例,女１９例（９０５％）,男２例。年龄中位数为３６岁。术前均明确诊断为胰岛素瘤。但曾误诊癫痫７例,精神病２例,误诊率４２８％。Ｂ超定位准确者７５％,ＣＴ定位准确者５０％。结论胰岛素瘤定位较困难;Ｂ超、ＣＴ是术前较为实用的定位检查方法;如经各种检查仍不能定位时,可根据临床表现施行剖腹探查。手术方式首选胰岛素瘤剜除术,必要时也可行胰十二指肠切除或胰体尾切除。对无法彻底切除的恶性胰岛细胞瘤,应尽量切除原发和转移病灶。     

Anatomy of handedness and the laterality of seizure onset: surgical implications of new understandings in motor control

Abstract

Objectives: This article pursues another corollary of the anatomy of handedness, a code for the laterality of motor control. The latter indicates the absence of any motor communication from the minor (right, in the vast majority of population) to the major hemisphere (left, in the vast majority of right handers). It also indicates that all communications between the two hemispheres are excitatory in nature. This arrangement prohibits initiation of seizure within the minor and its propagation to the major hemisphere, via the callosum.

Methods: A comprehensive review of the literature is undertaken regarding theoretical and technical reasons for the failure of seizure surgery in subjects undergoing the same for intractable epilepsy.

Results: Whereas the laterality of motor control is heavily biased towards the left hemisphere (～80%), the operation is performed equally on both hemispheres. Failures of surgery in some series were substantially higher among those who had undergone operations on the right hemisphere. Technical reasons for this are traced to the unreliability of tests commonly employed in securing laterality of seizure onset, which is the same as that of motor control. Accordingly, the failure rate of seizure surgery may equal the rate of false lateralization of the major hemisphere in these circumstances.

Conclusion: Given the dichotomous anatomy of handedness, the most robust test for lateralizing the hemisphere of onset of seizure is that of determining the reaction times of two symmetrically located effectors, one on each side of the body. The side with the shorter reaction time will always be opposite to the major hemisphere. The difference between the two values is commensurate to the inter-hemispheric transfer time.     

Localization of ictal and interictal bursting epileptogenic activity in focal cortical dysplasia: Agreement of magnetoencephalography and electrocorticography

Abstract

Focal cortical dysplasia (FCD) is often associated with severe partial epilepsy. In such cases, interictal frequent rhythmic bursting epileptiform activity (FBREA) on both scalp electroencephalography (EEG) and electrocorticography (ECoG) is generally accepted to be identical to the ictal epileptiform activity. We used magnetoencephalography (or Magnetic Source Imaging (MSI)) to determine the epileptogenic zone in a 6-year-old patient with histopathologically proven FCD and normal magnetic resonance imaging (MRI). MSI was used to localize the sources of both ictal activity and FRBEA, which was then compared with ECoG findings. The intracranial sources of both types of activity co-localized in the left inferior frontal and superior temporal gyri. The location and extent of the epileptogenic area determined by MSI was essentially identical to that determined directly through extra-operative ECoG. In the absence of structural abnormalities detectable on MRI, the noninvasive method of MSI provided valuable information regarding the location and extent of the primary epileptogenic area. This was critical for pre-surgical planning regarding placement of intracranial electrodes and for risk-benefit evaluation. [Neurol Res 2002; 24: 525-530]     

癫痫患者免疫功能和血浆皮质醇的观察

本文观察62例癫痫惠者的外周血T淋巴细胞亚群的分布、血清免疫球蛋白含量及20倒癫痫患者血浆皮质醇的水平,发现:癫痫患者外周血CD_3~+细胞、CD_4~+细胞、CD_8~+细胞数量均显著降低及血清IgA含量显著降低,与正常对照比较有显著性差异(P<0.01),这些异常改变与服用抗癫痫药物(中药或西药)、病程、病因分类及脑电图的异常亦无关。癫痫患者血浆皮质醇平均含量显著低于正常对照组(P<0.05)。提示癫痫患者的某些免疫功能异常可能与内分泌的改变有关。     

中药益脑安治疗癫痫的实验研究

为探讨本院中药制剂益胺安胶囊（由天麻、当归、全蝎等组成）抗癫痫的作用机制，随机将实验大鼠分为益胺安组、苯妥英钠组，空白组，进行大脑皮层痫样放电实验和美解眠惊厥发作阈实验，观察致痫放电的潜伏时，振幅及惊厥发作的潜伏时，持续时间，结果显示益胺安与苯妥英钠相似，均能延长致痫的潜伏时，降低致痫电位幅度、缩短惊厥发作的持续时间，并且未发现明显毒副作用。     

宁痫冲剂对戊四唑致痫大鼠脑神经元超微结构的影响

[目的]观察中药复方宁痫冲剂对戊四唑(PTZ)致痫大鼠大脑神经元超微结构的影响。[方法]SD大鼠40只,随机分为5组,即正常组、模型组,宁痫冲剂高、低刺量组(10、5 g·kg-1·d-1)和苯巴比妥组(60 mg·kg-1·d-1);除正常组外,其他组动物均以PTZ诱导复制慢性癫痫模型,造模同时给药,连续4周,待未次点燃测试后1 h,各组随机抽取2只大鼠,采用透射电镜法观察海马CA3区、额叶皮质神经元超微结构。[结果]模型组海马、额叶皮质神经元超微结构损伤显著:核膜边界不清或内陷,核质不均匀,异染色质增多、积聚成块、边集,胞质中线粒体肿胀、嵴断裂甚至空化,粗面内质网池扩张、核糖体脱落,游离核糖体解聚,甚至见胞浆空化;宁痈冲剂组海马、额叶皮质神经元损伤程度均明显减轻,其中低剂量组较高剂量组损伤更为轻浅,与苯巴比妥组相比未见显著性差异。[结论]戊四唑诱导慢性癫痫发作可致大鼠海马、额叶皮质神经元超微结构明显损伤,中药复方宁痫冲剂具有良好的抗损伤作用。     

The effects of continuous and single-dose radiation on choline uptake in organotypic tissue slice cultures of rabbit hippocampus

Abstract

The objective of the present study was to determine the time-dependent course of choline uptake in mature organotypic slice cultures of rabbit hippocampal formation and to assess the effects of continuous and single high-dose irradiation on choline uptake in cultivated slices in vitro. Transverse slices of hippocampus were dynamically incubated in a cerebrospinal fluid-like culture medium for 72 h. To study the changes in choline uptake longitudinally, the slice cultures were processed with 0.1 µ M [³H]-choline, and tritium accumulation was counted. Two different gamma irradiation sources (¹²⁵I seeds and a clinical ⁶⁰Co source) were used as representative models of interstitial radiosurgery and other radiosurgical techniques. A total dose of approximately 6000 cGy was delivered to the brain slices in one session or in a continuous, relatively low-dose rate fashion, and their effects on high-affinity choline uptake were examined. In another set of experiments with ¹²⁵I, 5 µM hemicholinium-3 was used in choline uptake procedures as a competitive high-affinity choline uptake inhibitor. The results can be summarized as follows: (1) in the control group of the hippocampal tissue culture, there was a significant increase in tritium accumulation values from 0 to 48 h and a decrease thereafter; (2) continuous ¹²⁵I irradiation caused a highly significant depression of the accumulation of tritium compared to that observed in the control group throughout its application for 72 h; (3) there was no significant change in the accumulation of tritium in the slices after single high-dose rate irradiation with a ⁶⁰Co source; and (4) 5 µM hemicholinium significantly depressed the accumulation of tritium in both the control and the ¹²⁵I-irradiated groups, and there was no longer a difference between ¹²⁵I-irradiated and control groups when both groups were treated with hemicholinium. These results demonstrate that the delivery of continuous but relatively low-dose rate gamma irradiation is more efficacious than single high-dose external irradiation on high-affinity choline uptake in hippocampal nervous tissue. The results also indicate that continuous irradiation specifically affected the high-affinity energy-dependent choline uptake mechanism, whereas nonspecific choline uptake did not seem to be disturbed. [Neurol Res 2001; 23: 669-675]     

Suppression of the multidrug transporter P-glycoprotein using RNA interference in cultured rat astrocytes induced by coriaria lactone

Abstract

The overexpression of the multidrug resistance gene (MDR-1) and its translational product p-glycoprotein (P-gp) may play an important role in pharmacoresistant epilepsy. We established the rat astrocyte model overexpressing P-gp induced by coriaria lactone and successfully nucleofected it with the siRNA-hairpin expression vector pSIREN-shuttle designed to target MDR-1B mRNA. The mRNA expression of MDR-1B gene was mostly knock down by 67.70% (p<0.01). The expression of P-gp in experimental group was significantly lower than that in negative control (p<0.05), and the rhodamine efflux ratio of experimental group (23.08%) was remarkably lower than that of negative control (78.35%, p<0.01). We first employed RNA interfering to the drug resistance reversal of refractory epilepsy and this may provide a new way for refractory epilepsy remedy.     

Antiepileptic activity of melatonin in guinea pigs with pentylenetetrazol-induced seizures

Abstract

Background: Antiepileptic and neuroprotective effects of melatonin (N-acetyl-5-methoxytryptamine) have been shown at higher doses (50–160 mg/kg). We aimed to investigate the antiepileptic effects of low-dose melatonin (10 mg/kg) on pentylenetetrazol (PTZ)-induced experimental epilepsy model.

Materials and Methods: Twelve male albino guinea pigs weighing 500–800 g were used in our work. Initially, latent period, seizure intensity and mortality parameters were evaluated during the epileptic seizure induced by PTZ. After a recovery period of 7 days, effects of the neuroprotective agent, melatonin (which is dissolved in 2.5% ethanol–saline solution), on epileptic seizures induced by PTZ were evaluated. Effects of 2.5% ethanol, which is an anticonvulsant agent when administered acutely in high concentrations, on PTZ-induced seizures were also evaluated.

Results: Data obtained from the study groups (PTZ, PTZ + melatonin and PTZ + ethanol) were evaluated by paired t-test, and p<0.005 was considered statistically significant. The differences of latent periods between the PTZ and PTZ + melatonin groups were found to be statistically significant (p<0.001).

Conclusion: Although melatonin does not have a primary anticonvulsant effect at low doses (10 mg/kg), it lowers the mortality rates and attenuates seizure severity while increasing the latent period.