Search for the cause of trigeminal neuralgia and development of its treatment procedures - Effects of newly developed gamma knife surgery -

伽玛刀手术（GKS）已越来越多地用于治疗各种适应症，包括动静脉畸形、脑肿瘤、帕金森病或局灶性癫痫。尽管在临床实践中，GKS被认为是一种安全有效的治疗这些疾病的方法，但对γ射线照射引起的生物学特性的改变知之甚少。在最近使用动物进行的研究中，已经表明高剂量伽马辐照引起毛细血管内皮细胞的显著变性，从而诱导辐照区域的水肿和坏死。位移的照射部位在anteromedical方向增加自发活动，和后外侧移位引起盘旋行为的阿朴吗啡测试。对100戈伊照射大鼠坐骨神经的观察表明，γ射线照射可能不影响正常神经的敏感性，但可影响炎症介质的释放或内源性抑制物的活性，近年来，GKS也被用于治疗顽固性疼痛，如三叉神经痛、丘脑痛和癌痛。对于三叉神经痛的治疗，使用4 mm准直器靶向并照射后半月神经，以提供90戈伊。所有患者在6个月内疼痛均显著减轻。因此，进行进一步的基础实验以确定使用GKS对许多领域的各种疾病的最佳治疗方案是非常重要的。

Gamma knife surgery (GKS) has been increasingly utilized to manage a wide variety of indications including arteriovenous malformations, brain tumors, Parkinson disease, or focal epilepsy. Although in clinical practice, GKS is thought to be a safe and effective treatment for these diseases, little is understood about the alteration of biological properties induced by gamma irradiation. In recent studies using animals, it has been shown that high-dose gamma irradiation causes marked degeneration of the capillary endothelial cells, consequently inducing edema and necrosis in the irradiated area. Displacement of the irradiation sites in the anteromedical direction increased spontaneous activity, and posterolateral shift provoked circling behavior on the apomorphin test. The observation of rat sciatic nerve irradiated by 100 Gy indicated that the gamma irradiation might not affect the sensitivity of the normal nerve, but does affect the release of inflammatory mediators or the activity of endogenous inhibitors.More recently, GKS has also been employed to treat intractable pain, such as trigeminal neuralgia, thalamic pain and cancer pain. For the treatment of trigeminal neuralgia, the retro gasserian was targeted and irradiated using a 4mm collimator to deliver 90 Gy. All patients experienced a significant pain reduction within 6 months. Thus, it is very important to conduct further basic experiments to determine the optimal treatment protocol using GKS for various diseases across many fields.