Peri-electrode large molecule microdialysis of the brain during induced seizures in mice, pigs, and humans with epilepsy undergoing resective surgery

有一个迫切的需求尚未得到满足，那就是确定新的策略来控制失败的癫痫患者的癫痫发作 对目前可用的药物做出反应。这些人中的许多人接受了侵入性手术切除 脑电异常组织。然而，在这些患者中，有多达一半的人可能会复发。 受试者在手术后5年内。对以电生理机制为靶点的治疗耐药 先前非发作组织的异常神经活动与手术后癫痫发作的复发相关 指出非神经性和自我放大的致痫驱动因素的作用。多项研究表明 癫痫患者和类固醇等患者外周炎症因子的变化 免疫调节疗法已被证明在一些患者中有效。同样，来自动物模型的证据 明确支持细胞因子，如肿瘤坏死因子α和白介素1β在癫痫发作活动中的作用。因此，神经性炎症 可能是抗药性癫痫的关键驱动因素。这一提议的中心假设是， 神经活动触发局部趋化因子和细胞因子的释放，从而促进先天的渗透 炎性效应细胞，产生额外的炎性介质，并进一步破坏神经 电路。打破这一循环可能会阻止细胞分裂和/或癫痫的发生。这一点的具体假设 建议化学诱导剂CCL2和效应细胞因子肿瘤坏死因子α、白介素1β和/或白介素6的水平是 与化学诱导的癫痫样活动在空间和时间上的相关性升高。这一假说将 使用基于同时收集皮质内脑电活动和大分子的策略进行测试 微透析法测定小鼠电极周围间隙细胞外液中的炎性介质 和猪，以及正在接受抗药性癫痫切除手术的人类。尽管是间接的 人类的证据表明炎症在癫痫和癫痫中的作用，目前还没有研究 测量癫痫脑内原位炎症特征或评估两者之间的关系 癫痫样活动和炎症分子的局部释放。尽管脑微透析已经被 作为一种在神经危重护理环境中评估小分子的技术，这项研究将被 首家采用创新策略，将颅内脑电采集和HIGH的使用相结合 用于捕获周围组织中趋化因子和细胞因子的分子量截止膜(100 KDa) 电极间距。这些实验意义重大，因为它们将提供对 炎症介质既是神经回路功能障碍的原因又是结果，它们可以识别个体 炎症驱动因素，可作为个性化治疗策略的目标。不管结果如何，这 研究将产生关于癫痫发作活动和炎症之间相互作用的新的基础知识。 了解这种关系可能会为数百万人使用免疫调节疗法提供支持 目前的护理标准没有为癫痫患者提供足够的服务。

There is a critical unmet need to identify new strategies to control seizures in individuals with epilepsy who fail to respond to currently available drugs. Many of these individuals undergo invasive surgical resection of electroencephalographically aberrant tissue. However, seizures are likely to recur in up to half of these subjects within 5 years of surgery. Resistance to therapies that target electrophysiological mechanisms of aberrant neural activity coupled to post-surgical recurrence of seizures in previously non-ictal tissue may indicate a role for epileptogenic drivers that are non-neural and self-amplifying. Multiple studies have demonstrated changes in peripheral inflammatory factors in individuals with epilepsy, and steroids and other immunomodulatory therapies have proven effective in some patients. Likewise, evidence from animal models clearly supports a role for cytokines such as TNFα and IL1β in seizure activity. Therefore, neuroinflammation may be a critical driver of drug-resistant epilepsy. The central hypothesis of this proposal is that aberrant neural activity triggers local release of chemokines and cytokines that promote infiltration of innate inflammatory effector cells, production of additional inflammatory mediators, and further disruption of neural circuitry. Breaking this cycle may stop ictogenesis and/or epileptogenesis. The specific hypothesis of this proposal is that levels of the chemoattractant CCL2 and the effector cytokines TNFα, IL1β, and/or IL6 are elevated in spatial and temporal association with chemically induced epileptiform activity. This hypothesis will be tested using a strategy based on simultaneous collection of intracortical EEG activity and large molecule microdialysis to measure inflammatory mediators in the extracellular fluid of the peri-electrode space in mice and pigs and in humans undergoing resective surgery for drug-resistant epilepsy. Despite circumstantial evidence in humans indicating a role for inflammation in seizure disorders and epilepsy, no study has yet measured the in situ inflammatory characteristics of the epileptic brain or assessed the relationship between epileptiform activity and local release of inflammatory molecules. Though brain microdialysis has been established as a technique in the neurocritical care setting for assessment of small molecules, this study will be the first to employ an innovative strategy that combines intracranial EEG collection and the use of high molecular weight cut-off membranes (100 kDa) for the capture of chemokines and cytokines in the peri- electrode space. These experiments are significant as they will provide novel insights into the role of inflammatory mediators as both cause and effect of neural circuit dysfunction and they may identify individual inflammatory drivers that can be targeted for personalized treatment strategies. Regardless of outcomes, this study will generate new, fundamental knowledge about the interplay between seizure activity and inflammation. Understanding this relationship may provide support for the use of immunomodulatory therapies in the millions of individuals with epilepsy that are currently underserved by current standards of care.