Less Invasive Treatment for intractable Epilepsy Combined with Magnetoencephalography and Radiosurgery

为了探讨脑磁图（MEG）和放射外科联合治疗顽固性癫痫的微创治疗的可能性，进行了基础和临床研究。大鼠动物实验表明，立体定向单组分辐射引起靶部位坏死的最小剂量为75 Gy，如果持续1年，甚至25 Gy也可能引起坏死。用大鼠实验评价了辐照治疗癫痫性惊厥的效果。杏仁核点燃大鼠颞叶立体定向照射显示同侧照射增加放电后阈值，对侧照射抑制抽搐泛化。在神经外科手术中验证了诱发脑磁图功能映射的准确性。术中监测联合神经导航系统与术前MEG功能作图具有良好的相关性，验证了其准确性和作为一种微创术前评价方法的价值。探讨了脑磁图对癫痫病灶及其传播的评价能力。MEG成功地显示了伽马带放电并定位了焦点。在颞叶癫痫中，不仅可以检测到癫痫放电的焦点，还可以检测到其向对侧半球的传播。在复杂部分性癫痫患者中，脑磁图也能检测到尖峰爆发的近颞起源。

To investigate the possibility of less invasive treatment for intractable epilepsy combined with magnetoencephalography (MEG) and radiosurgery, basic and clinical research has been performed. Animal experiment using rats showed that minimum required dose to create necrosis at the target site by stereotactic single fraction radiation is 75 Gy and even 25 Gy may create necrosis if it were followed for 1 year. Effects of irradiation for epileptic convulsion are evaluated by experiments using rat. Stereotactic irradiation to temporal lobe in amygdala kindled rats showed that ipsilateral irradiation increases threshold of after-discharge and contralateral irradiation inhibit generalization of convulsion. Accuracy of functional mapping by evoked MEG was verified in neurosurgical procedures. Intraoperative monitoring combined with neuronavigation system showed good correlation with preoperative functional mapping by MEG and verified its accuracy and value as a less invasive preoperative evaluation method. Ability of MEG for evaluating epileptic foci and its propagation is accessed. MEG successfully showed gamma-band discharge and localized its focus. In temporal lobe epilepsy, not only the focus of epileptic discharge but also its propagation to contralateral hemisphere is detected. MEG also detects mesial temporal origin of spike bursts in patient with complex partial seizure.