Comparison of sensory and sympathetic innervation of the dura mater and posterior longitudinal ligament in the cervical spine after removal of the stellate ganglion

Although cervical spinal tissues are rich in sensory and sympathetic fibers , which play a significant role in clinical phenomena, there is little info rmation available regarding their anatomical characteristics. In this study , we compared the innervation of the cervical dura mater and the posterior longitudinal ligament (PLL) to that after removal of the stellate ganglion to determine whether the anatomical background plays a significant role in clinical manifestations. Immunoreactivities for calcitonin gene-related pep tide (CGRP) and substance P (SP) were used as sensory markers, and immunore activity for neuropeptide Y (NPY) was used as a sympathetic marker. Sensory fibers in the cervical dura mater were distributed within each cervical se gment, but those in the PLL extended beyond the segmental borders. A dense sensory fiber network forming a single layer was seen at the intervertebral disc region in the cervical PLL, whereas sympathetic fibers in this region were sparsely distributed. Sympathetic fibers were distributed not only ar ound the vascular wall but also in the region independent from vessels, and some occasionally ran together with sensory fibers in both the dura mater and the PLL. Removal of the stellate ganglion had little effect on the dist ribution of sensory fibers but denervated the sympathetic fiber networks in the region independent from vessels of the upper ipsilateral cervical PLL. In conclusion, the cervical dura mater and the PLL have different sensory and sympathetic innervations. Sympathetic fibers pass through the stellate ganglion to project to the region independent from vessels in the upper cer vical PLL. Clinical symptoms may be attributed to this characteristic inner vation of the cervical spine. (C) 2001 Wiley-Liss, Inc.