The Sinuvertebral Nerve Revisited: A Morphological and Immunohistochemical Study

Area of Science:

• Anatomy
• Neuroscience
• Histology

Background:

• The sinuvertebral nerve (SVN) is implicated in discogenic low-back pain, yet its precise characterization is inconsistent.
• Previous studies faced technical challenges, leading to data disparities despite increased research.
• Key aspects of the SVN's nature remain unpublished, necessitating further investigation.

Purpose of the Study:

• To anatomically and histologically characterize the sinuvertebral nerve (SVN) in human cadavers.
• To determine the neurochemical profile of the SVN using immunohistochemistry.
• To provide a pathophysiological basis for SVN blockade in managing discogenic low-back pain.

Main Methods:

• Dissection of 100 vertebral column segments (L1-L5) from 10 adult human cadavers.
• Histological processing of SVN samples, including paraffin embedding and serial sectioning.
• Immunohistochemical analysis for Calcitonin Gene-Related Peptide (CGRP) and Vasoactive Intestinal Peptide (VIP).

Main Results:

• The SVN presented as a single branch (pattern I) in 85.4% of cases and two branches (pattern II) in 14.6%.
• No significant differences were observed based on vertebral level, side, or sex.
• All analyzed SVN samples were positive for CGRP and VIP, indicating mixed sensory and autonomic fibers.

Conclusions:

• The sinuvertebral nerve (SVN) exhibits a mixed fiber composition (sensory CGRP+ and autonomic VIP+).
• This neurochemical profile was confirmed directly within the SVN, not its target structures.
• Findings support the pathophysiological rationale for SVN blockade in diagnostic and therapeutic interventions for discogenic lumbar pain.