颈交感神经节节后纤维在颈椎后纵韧带上节段分布及其介导不同交感神经症状的研究

The etiology and pathogenesis of cervical spondylosis with sympathetic symptoms remain unclear. In our previous study, we have demonstrated the existence of sympathetic nerve fibers on the posterior longitudinal ligament (PLL) and those fibers mediated sympathetic symptoms. This finding is able to make a good explaination of the relaxation of sympathetic symptoms after anterior cervical surgeries. However, how to confirm the responsible segments preoperatively has been still unknown,which is extremely important in the treatment of this disease.In this study, when stimulation acted on a certain segment of PLL, different intensities of abnormanl signals would be recorded in the superior, middle and inferior cervical sympathetic ganglions (CSGs).Based on this finding,we suppose that there may be a corresponding relationship between the sympathetic nerve fibers on different levels of PLL and the three CSGs.Stimulations acted on different levels of PLL may induce abnormal discharge in the corresponding CSG, which leads to various sympathetic symptoms caused by corresponding effector organs.Therefore,it is possible to confirm the responsible segments according to the abnormal signals from the CSGs and corresponding clinical manifestations.The project intends to study the segmental distribution of sympathetic post-ganglia fibers on the cervical PLL of beagle dogs by neural tracer,and then identify the corresponding relationship between the characteristics of distribution and different sympathetic effector organs, in the purpose of confirming the responsible segment which invokes sympathetic symptoms.

伴交感神经症状颈椎病的病因与发病机制一直难以明确。项目组在前期研究中首次提出并证实颈椎后纵韧带（PLL）上分布有交感神经纤维并介导了交感神经症状的发生。尽管这一发现可解释部分患者颈前路手术切除PLL后，交感神经症状可明显缓解的现象，但如何在术前判断病变责任节段成为项目组难以回避的问题。前期研究中我们发现：刺激颈椎某一节段PLL，在颈上、颈中、颈下交感神经节（CSG）上均可接收到电位信号，且其信号强度不尽相同。由此推测：颈椎不同节段PLL上交感神经纤维分布与CSG可能存在某种对应关系；刺激不同节段PLL会引起相应CSG异常放电，进而影响其交感神经纤维所支配的效应器官。诚然如此，即可通过不同CSG的异常信号和不同临床症状来判断病变节段。本项目组拟采用神经示踪等方法研究比格犬CSG节后纤维在颈椎PLL上的节段分布特点，讨论其与不同交感神经效应器官的对应关系，从而明确产生交感神经症状的责任节段。

伴交感神经症状颈椎病是比较特殊的一种颈椎病，主要症状表现为眩晕、耳鸣、血压波动、腹胀等交感症状，但体格检查等常规手段无法确诊。其发病机制尚未明确，有许多假说试图解释这一病因，但未得公认。本项目以颈椎后纵韧带交感神经激惹学说着手，通过形态学研究、电生理学研究、神经示踪等方法，初步探明颈椎不同节段后纵韧带上交感神经纤维的分布规律，及其相对应的不同症状之间存在对应关系。实验方法为：取实验动物若干，分为实验组和对照组，麻醉后暴露手术区域，刺激不同节段的颈交感神经节，记录血压、呼吸频率、胃肠道平滑肌电位等指标的前后变化。而后进行统计学分析。形态学实验发现：经过特异性NPY染色，观察到后纵韧带表面分布的神经纤维和颈交感神经节的来源相同。电生理学实验发现：颈上、中、下神经节分别与C3/4、C4-6、C6/7水平的后纵韧带上交感神经纤维相对应。电刺激不同节段的实验动物颈部交感神经节，分别观察呼吸频率、血压、胃肠平滑肌电位等指标变化，结果提示，颈上神经节(C4/5)参与了呼吸频率的调节，颈上、中交感神经节（C5/6）可能参与了血压的调节，颈上、下神经节（C3/4，6/7）参与了胃肠平滑肌电位的调节。由此得出以下结论：1、形态学研究基本证实了交感神经存在于后纵韧带，且具有一定的规律。2、通过效应器研究明确了不同部位交感神经节和症状对应关系。3、通过不同症状判断，对发现伴交感神经症状颈椎病的病变节段具有一定的指导意义。