Responses Of Cervical Sympathetic Ganglion To The Stimulations Of Posterior Longitudinal Ligament In Beagles

ObjectiveWith the increasing pressure for working and living, people suffering from cervicalspondylosis, especially in those patients with sympathetic symptoms, who usuallycomplained of dizzy, become more and more popular. Such disease puzzled spinalsurgeries a lot for treating. This research base on the hypothesis of sympathetic nervesfactors in cervical posterior longitudinal ligament (PLL), studying the responses in cervicalsympathetic ganglion evoked by varieties of stimulation of the cervical PLL in beagle dogs,in the purpose of looking for the theoretical basis for treating cervical spondylosis withsympathetic symptoms.MethodIn2beagle dogs, detail anatomy was made in anterior region of neck, observing thedistribution and the course of musculi colli and sympathetic trunk, learning the anatomicmorphology of cervical vertebra.Different levels of electrical stimulations (range from20mV to100mV) was set tostimulate the PLL of6different beagle dogs, while receiver electrode was located atmiddle cervical ganglion (MCG), recording the electric signal from the ganglion. Laterthen, sympathetic block was made on the PLL by lidocaine, and electric signal fromsympathetic ganglion was recorded again under the same intensity of electrical stimulation.The two amplitudes of electric signal waveforms and response time were compared beforeand after sympathetic block.PLL compression models were established in4healthy adult beagle dogs, which wereunderwent the process of cervical discectomy, nucleus pulposus replantation and platesfixation. Sympathetic nerve activities were recorded before operations, after the establishedof cervical spondylosis models immediately and2months later, comparing the threegroups of electric signal waveforms form, parameters and functional spectrum density.ResultThe vagosympathetic truck lies in the deep side of the musculus sternocephalicus, onthe surface of Musculus longus colli and Musculus longus capitis, aside the musculus sternothyroideus and musculus sternohyoideus, inside the carotid sheath, and accompaniedwith the common carotid artery and the internal jugular vein. Superior cervical ganglionlocates at the level of C1. Middle cervical ganglion (MCG) locates at the place ahead thetransverse process of C6~7. MCG provides sympathetic inputs deeply into thepostmediastinum, where the nerve fibers gathered to be the cervicothoracic ganglion (CTG)at the level of T1. Parts of the nerve fibers go downward to be the thoracic sympathetictrunk, which becomes a thoracic sympathetic ganglion at the lower edge of each rib, andprovides communicant ramus into spinal canal.Single pulse electrical stimulation of PLL evoked bi-direction waves which wererecorded on sympathetic ganglion. Amplitude of the waveforms increased with thestimulus intensity, while response time was independent of the stimulus intensity. TheAmplitudes of the waves were significantly decreased after sympathetic nerves block onPLL, and the response time were significantly prolonged.Biological experimental system recorded a Smooth waveform from the cervicalsympathetic ganglion. After a compression was made on the PLL, a steady waveform wasrecorded as well. However, Waveforms change a lot in those cervical spondylosis modelsafter2months’ feeding. The100~250Hz frequency component increased in functionalspectrum of2months’ cervical spondylosis models compared to other two situations.ConclusionThere was a certain relationship between posterior longitudinal ligament and cervicalsympathetic ganglion. It is recommended to block the sympathetic factors of PLL, whichcould be considered as a part of sympathetic nerves system, to relieve sympatheticsymptoms. The acute compression on the PLL is not the main reason of cervicogenicsympathetic symptoms. However, Local inflammatory cytokines caused by long-term discherniation acting on PLL could be considered one of the most important factors in leadingto sympathetic symptoms.