NEUROPHYSIOLOGY OF TRIGEMINAL NEURALGIA

三叉神经痛是一种严重的、反复的(间歇性，但其他情况下为慢性)面部疼痛综合征，主要影响老年患者。三叉神经痛的独特之处在于其阵发性疼痛、剧烈疼痛、疼痛性质和局限于三叉神经系统。对于这种疾病，有各种内科和外科治疗方法可用，但没有一种是统一和永久有效的。由于缺乏对这种疾病的神经学基础的基本了解，三叉神经痛的长期治疗的实质性改善可能会受到阻碍。过去有过涉及外周神经系统异常感觉输入和/或中枢神经系统突触处理改变的理论，但到目前为止还没有直接的实验证据支持这些理论。在缺乏合适的三叉神经痛动物模型的情况下，起源理论必须在有症状的人类患者身上进行测试。本研究方案的目的是应用一种新的显微神经成像记录技术来直接研究三叉神经痛患者三叉神经节神经元的神经生理特征。我们开发的这项技术允许在患者接受经皮神经节松解术治疗疼痛之前，术中记录三叉神经节的微电极。这项拟议的研究将检验光机械刺激触发区是否会引起三叉神经初级传入神经元异常的(自我维持的)动作电位放电。对轴突的电刺激将被用来检测三叉神经节神经元的根或体细胞中的自动节律活动。最后，将尝试确定三叉神经节神经元中可能发生的动作电位放电，同时患者有三叉神经痛的经历。预计术中记录将首次提供三叉神经痛与来自周围神经系统的异常感觉输入有关的直接证据。合唱团对阵发性疼痛期间神经或神经节中的脉冲交通进行了观察，这将极大地阐明三叉神经痛的神经机制，允许在实验动物中建立综合征的模型，并指导对这种和其他神经性疼痛障碍的阵发性疼痛进行更好的内科和外科治疗的研究。

Trigeminal neuralgia is a severe, recurrent (episodic, but otherwise chronic) facial pain syndrome which affects chiefly older patients. The pain of trigeminal neuralgia is unique in its paroxysmal nature, excruciating intensity, lancinating quality, and confinement to the trigeminal nervous system. Various medical and surgical treatments are available for this disorder, but none is uniformly and permanently effective. It appears that a substantial improvement in the long-term treatment of trigeminal neuralgia may be hindered by the lack of basic understanding of the neurological basis of this disorder. Theories involving abnormal sensory input from the peripheral nervous system and/or alteration of synaptic processing in the central nervous system have been invoked in the past, but thus far there is no direct experimental evidence to support them. In the absence of an adequate animal model of trigeminal neuralgia, theories of genesis have to be tested in symptomatic human patients. The goal of this research proposal is to apply a novel micro-neurographic recording technique to study directly the neurophysiological characteristics of trigeminal ganglion neurons in patients with trigeminal neuralgia. The technique, which we have developed, allows intra-operative microelectrode recordings in the trigeminal ganglion before the patients undergo percutaneous gangliolysis for treatment of the pain. The proposed study will examine if light mechanical stimulation of the trigger zone elicits abnormal (self-sustained) action potential discharge in trigeminal primary afferent neurons. Electrical stimulation of the axons will be used to detect auto-rhythmic activity in the roots or somata of trigeminal ganglion neurons. Finally, an attempt will be made to identify action potential discharges which may occur in trigeminal gang!ion neurons concurrent with patient's experience of trigeminal neuralgic pain. It is anticipated that intra-operative recordings will provide, for the first time, direct evidence that trigeminal neuralgia is associated with abnormal sensory input from the peripheral nervous system. Choral made observations of impulse traffic in the nerve or ganglion during paroxysms of pain should greatly illuminate the neural mechanism of trigeminal neuralgia, allow for modelling of the syndrome in experimental animals, and direct research toward better medical and surgical treatment of pain paroxysms in this and other neuropathic pain disorders.