低频率电刺激对癫痫灶点转移的作用及初步机制研究

发布时间：2019-05-15 18:24

【摘要】：癫痫(epilepsy)是由于大脑皮层的异常放电引起的中枢神经系统慢性疾病。"灶点转移"(positive transfer of secondary focus)是指在癫痫患者中随着原发致痫灶的反复发作进展,引起在原发致痫灶以外的脑区出现非结构改变的新的致痫灶。有超过30%的癫痫患者在长期、反复的原发致痫灶发展过程中,会出现灶点转移的现象,转移的部位可发生在包括颞叶、额叶等多个脑区。当新发致痫灶的部位位于原发致痫灶(primary fo cus,或称第一灶点)的对侧半球中相对应的镜像部位时,称为镜灶(mirror focus)灶点转移。目前,有灶点转移的癫痫患者发生耐药性的概率非常高,而且手术的预后也非常差。长期无法控制的反复发作给患者造成了沉重的负担,严重者甚至致残、致死。而长期的治疗费用也给社会造成了沉重的经济负担。因此,寻找针对灶点转移的有效治疗手段显得非常必要。深部脑刺激(Deepbrain stimulation,DBS)是目前治疗癫痫的一种新的有前景的治疗手段。临床前和临床研究显示,DBS特定靶区可以明显抑制多种癫痫类型的发作。尤其是低频率电刺激(LFS)在抑制癫痫方面显示了较好的耐受性,可控性及较小的组织损伤等特点。我们课题组前期一系列研究发现LFS作用于致痫灶及之外的关键脑区,如内嗅皮层,梨状皮层及丘脑前核等可以有效抑制癫痫发作,并且可以抑制癫痫的形成。因此,我们推测,LFS可能可以抑制癫痫的灶点转移现象。因此,在本博士论文的第一部分,我们主要研究了 LFS作用于第一致痫灶时对第二致痫灶的形成过程(灶点转移)的作用及特点,并对LFS抑制癫痫灶点转移的可能途径进行探究。而在第二部分,我们通过分析动物模型及颞叶癫痫患者中相关蛋白变化,试图探究灶点转移是否可以被特定生物标记物所预测。第一部分低频率电刺激抑制癫痫灶点转移的作用及特点探究在本研究中,我们利用大鼠杏仁核电点燃癫痫模型,发现当有第一灶点(右侧杏仁核)完全点燃形成致痫灶的基础上,第二灶点(镜灶侧,左侧杏仁核)癫痫的发生受到促进;并且通过电损毁实验我们证明这一促进作用是非依赖与第一灶点独立存在的。进一步我们发现LFS直接作用于第一灶点能够延缓第二灶点致痫过程,表明LFS可能具有延缓灶点转移发生的作用。第一灶点形成早期对第二灶点等级进展即出现促进作用,而在第一灶点形成晚期,对第二灶点等级进展及后放电时长均有促进作用;根据这一研究现象,我们在第一灶点形成后期再开始给予LFS,发现此时LFS仅能减弱第二灶点的后放电时长,不能延缓其等级的进展速度。同时,我们进一步探究了当第二灶点为同侧海马的情况,相似的,第一灶点同样可促进第二灶点的致痫过程。从本研究中我们第一次提出LFS作用于原灶点(第一灶点)能够对第二灶点的形成起到作用,为LFS治疗颞叶癫痫中灶点转移提供理论依据。第二部分低频电刺激在灶点转移中涉及的蛋白调控及灶点转移临床病例探究目前,灶点转移缺乏有效的预测指标。在本研究中,我们对电点燃第一灶点形成、LFS干预第一灶点电点燃过程以及完全空白(正常)的实验动物脑组织双侧灶点及双侧海马氯离子通道蛋白KCC2进行检测,发现第一灶点形成后,在双侧灶点(双侧杏仁核)区及双侧海马中,KCC2的表达相对完全空白动物的脑组织有所下降,而在LFS给予干预后,这种表达下降的趋势得到逆转。进一步对比癫痫患者的脑组织样本我们发现,相比只存在一个灶点的癫痫患者,在具有灶点转移的癫痫患者脑组织中存在KCC2的低表达水平,提示KCC2可能成为指证灶点转移的生物标记物。
[Abstract]:Epilepsy is a chronic disease of the central nervous system due to the abnormal discharge of the cerebral cortex. The "range transfer" transfer of secondary focus refers to a new approach to the non-structural change of the brain regions other than the primary cause of epilepsy in the patients with epilepsy with the progression of the repeated onset of the primary focus. There are more than 30% of the patients with epilepsy in the long-term and recurrent primary and secondary development process. The transfer of the focal point may occur in a plurality of brain regions including the leaves, the frontal lobe, and the like. The mirror focus is referred to as a mirror focus point transfer when the site of the new hair-burning range is located at the corresponding mirror site in the opposite hemisphere of the primary fo cus, or the first range. At present, the probability of drug resistance in epileptic patients with focal point transfer is very high, and the prognosis of the operation is also very poor. Repeated episodes beyond the control of the long term cause a heavy burden on the patient, and the serious person is even disabled and fatal. The long-term treatment cost also has a heavy economic burden on the society. Therefore, it is necessary to find effective means of treatment for the transfer of the focal point. Deep brain stimulation (DBS) is a new promising treatment for the treatment of epilepsy. Pre-clinical and clinical studies have shown that DBS-specific target areas can significantly inhibit the onset of multiple types of epilepsy. In particular, that low-frequency electrical stimulation (LFS) show good tolerance, controllability and small tissue damage in the aspect of inhibition of epilepsy. The previous series of studies in our research group found that LFS can effectively inhibit the seizure and can inhibit the formation of epilepsy, such as the internal olfactory cortex, the pear-shaped cortex and the anterior nucleus of the thalamus. Therefore, we have speculated that LFS may be able to suppress the focal point transfer of the epilepsy. Therefore, in the first part of this dissertation, we mainly study the effect and characteristics of LFS on the formation process (focal point transfer) of the second cooking range, and explore the possible ways to inhibit the transfer of the focal point of the epilepsy. In the second part, we try to explore whether the focal point transfer can be predicted by a specific biomarker by analyzing the related protein changes in the animal model and the patients with epilepsy. In this study, we used the rat almonds nuclear power to ignite the epileptic model, and it was found that when the first range (right amygdala) was completely ignited to form the epileptogenic focus, the second range (the side of the mirror) was found. The occurrence of the left-hand amygdala is promoted; and by electrical damage experiments we have shown that this contribution is non-dependent and independent of the first focal point. Further, we find that LFS can delay the second range point-causing process directly on the first range point, indicating that the LFS may have the function of delaying the transfer of the stove point. the first range point is formed in the early stage to promote the second range point level, and the advanced stage is formed at the first range point, and the progress of the second range point level and the time duration after the discharge are promoted; and according to the research phenomenon, we begin to give the LFS at the later stage of the first range point formation, It is found that the LFS can only reduce the post-discharge duration of the second range, and can not delay the progression rate of the grade. At the same time, we further explore the case where the second range point is the ipsilateral hippocampus, similar, the first range point can also promote the second range point. For the first time in this study, we proposed that LFS can play an important role in the formation of the second range, and provide a theoretical basis for the treatment of focal point metastasis in the patients with epilepsy. The second part of low-frequency electrical stimulation involved in the shift of the focal point involved in the control of the protein and the clinical case of the shift of the focal point. in this study, we found that the first range point and the bilateral hippocampal chloride channel protein KCC2 were detected by the LFS intervention for the first range point formation, the LFS intervention of the first range point electrical ignition process and the complete blank (normal), and after the first range point was found to be formed, In both bilateral (bilateral amygdala) and bilateral hippocampus, the expression of KCC2 decreased relative to the brain tissue of completely blank animals, and the trend of this decline was reversed after the intervention of LFS. We found that there was a low level of expression of KCC2 in the brain tissue of epileptic patients with focal point metastasis, suggesting that the KCC2 might be a biomarker for the transfer of the point of range.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R742.1

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