Magnetic Resonance Imaging Undetectable Epiduroscopic Hotspot in Chronic Diskogenic Back Pain-Does Sinuvertebral Neuropathy Actually Exist?

Neuroinflammation and nociception in intervertebral disc degeneration: a review of precision medicine perspective

Intervertebral disc (IVD) degeneration is a major cause of low back pain (LBP), which results in disability worldwide. However, the pathogenesis of IVD degeneration mediating LBP remains unclear. Current conservative treatments and surgical interventions are both to relieve the symptoms and minimise pain; nevertheless, they are unable to reverse the degeneration. Previous studies have shown that inflammation and nociception markers are important indicators of pain mechanisms in IVD degeneration underlying LBP. As such, multiomics profiling allows the discovery of these target markers to understand the key pathological mechanisms mediating IVD degeneration underpinnings of LBP. This article provides insights into a precision medicine approach for identifying and understanding the pathophysiology of IVD degeneration associated with LPB based on the severity of the disease from early and mild to severe degenerative stages. Molecular profiling of key markers in degenerative IVDs based on patient stratification at early, mild, and severe stages will contribute to the identification of target markers associated with signalling pathways in mediating neuroinflammation, innervation, and nociception underlying painful IVD degeneration. This approach will offer an understanding of establishing personalised clinical strategies tailored to the severity of IVD degeneration for the treatment of LBP.

Anatomic zone division and clinical significance of the lumbar sinuvertebral nerves

BACKGROUND CONTEXT

Discogenic low-back pain (DLBP) is one of the primary causes of low back pain (LBP) and is associated with internal disk disruptions and is mainly transmitted by the sinuvertebral nerve (SVN). The lack of a universal understanding of the anatomical characteristics of the SVN has compromised surgical treatment for DLPB.

PURPOSE

This study aims to elaborate on the anatomical characteristics of the SVN and to discuss their possible clinical significance.

STUDY DESIGN

The SVNs were dissected and immunostained in ten human lumbar specimens.

METHODS

The SVNs at the segments from L1-L2 to L5-S1 in ten human cadavers were studied, and the number, origin, course, diameter, anastomotic branches, and branching points of the SVNs were documented. Three longitudinal and five transverse zones were defined in the dorsal coronal plane of the vertebral body and disc. The vertebrae were divided longitudinally as follows: the region between the medial edges of the bilateral pedicles is divided into three equal parts, the middle third is zone I and the lateral third on both sides are zones II; the areas lateral to the medial margin of the pedicle were zones Ⅲ.The transverse zones were designated as follows: a)superior margin of the vertebral body to superior margin of the pedicle; b) between superior and inferior margins of the pedicle; c) inferior margin of the pedicle to inferior margin of the vertebral body; d) superior margin of the disc to the midline of the disc; and e) midline of the disc to the inferior margin of the disc. The distribution characteristics of SVNs in various zones were recorded, and tissue sections were immunostained with anti-NF 200 and anti-PGP 9.5.

RESULTS

The SVNs are divided into main trunks and deputy branches, with 109 main trunks and 451 deputy branches identified in the 100 lumbar intervertebral foramens (IVFs). The main trunks of the SVN originate from the spinal nerve and/or the communicating branch, but the deputy branch originating from both roots was not observed. All the main trunks and deputy branches of the SVNs originate from the posterolateral disc (Ⅲ d and Ⅲ e). The deputy branches of the SVN primarily innervate the posterolateral aspect of the intervertebral disc (Ⅲ d 46.78%, Ⅲ e 36.36%) and the subpedicular vertebral body (Ⅲ c 16.85%). The main trunk of the SVNs passes primarily through the subpedicular vertebral body (Ⅲ c 96.33%) and divides into ascending, transverse, and descending branches in the IVF: Ⅲ c (23/101, 22.77%) or spinal canal: Ⅱ c (73/101, 72.28%), Ⅱ d (3/101, 2.97%), Ⅱ b (2/101, 1.98%). The main trunk possesses extensive innervation, and except for the most medial discs (Ⅰ d and Ⅰ e), it almost dominates all other zones of the spinal canal. At the segments from L1-L2 to L5-S1, 39 ipsilateral anastomoses connecting the ascending branch to the main trunk or spinal nerve at the upper level were observed, with one contralateral anastomosis observed at L5.

CONCLUSION

The zone distribution characteristics of SVNs are similar across all levels. Comparatively, the proportion of double-root origin and the number of insertion points of the SVNs increased at the lower level. The three types of anastomosis offer connections between SVNs at the same level and at different levels. The posteromedial disc is innervated by corresponding and subjacent main trunks, with the posterolateral disc mainly innervated by the deputy branch.

CLINICAL SIGNIFICANCE

Detailed information and zone distribution characteristics of the lumbar SVNs can help improve clinicians' understanding of DLBP and improve the effectiveness of treatments targeting the SVNs.

Peripheral and Central Pathological Mechanisms of Chronic Low Back Pain: A Narrative Review

Chronic low back pain (CLBP), lasting >3 months, is the end result of multiple pathogenic factors. Unfortunately, little is known about CLBP pathogenesis, which limits its advancements in clinical therapy and disease management. This paper summarizes the known pathological axes of CLBP, involving both peripheral and central systems. In particular, this paper details injurious nerve stimulation, inflammation-induced peripheral pathway, and central sensitization. Lumbar components, such as intervertebral disc (IVD), facet joints, muscles, fascia, ligaments, and joint capsules, contain pain receptors called nociceptors. Degeneration of the aforementioned lumbar components activates inflammatory pathways, which can directly damage nerves, lower nociceptor threshold to fire action potentials (AP), and cause pain. Additionally, damaged lumbar IVDs and endplates can also lead to the pathologic invasion of nerve growth and innervation, followed by the compression of herniated IVDs on nerve roots, thereby causing traumatic neuropathic pain. The central mechanism of CLBP involves alteration of the sensory processing of the brain and malfunction of the descending pain modulatory system, which facilitates pain amplification in the center nervous system (CNS). Lastly, abnormalities in the brain biochemical metabolism, activation of glial cells, and subsequent inflammation also play important roles in CLBP development. Taken together, inflammation plays an important role in both peripheral and central sensitization of CLBP. Due to the heterogeneity of CLBP, its pathological mechanism remains complex and difficult to understand. Therefore, it is a worthy field for future research into the subcomponents of CLBP pathogenesis, in order to distinguish the specific form of the disease, identify its origins, and develop corresponding highly effective comprehensive therapy against CLBP.

Lumbar Degenerative Disease Part 1: Anatomy and Pathophysiology of Intervertebral Discogenic Pain and Radiofrequency Ablation of Basivertebral and Sinuvertebral Nerve Treatment for Chronic Discogenic Back Pain: A Prospective Case Series and Review of Literature

Degenerative disc disease is a leading cause of chronic back pain in the aging population in the world. Sinuvertebral nerve and basivertebral nerve are postulated to be associated with the pain pathway as a result of neurotization. Our goal is to perform a prospective study using radiofrequency ablation on sinuvertebral nerve and basivertebral nerve; evaluating its short and long term effect on pain score, disability score and patients’ outcome. A review in literature is done on the pathoanatomy, pathophysiology and pain generation pathway in degenerative disc disease and chronic back pain. 30 patients with 38 levels of intervertebral disc presented with discogenic back pain with bulging degenerative intervertebral disc or spinal stenosis underwent Uniportal Full Endoscopic Radiofrequency Ablation application through either Transforaminal or Interlaminar Endoscopic Approaches. Their preoperative characteristics are recorded and prospective data was collected for Visualized Analogue Scale, Oswestry Disability Index and MacNab Criteria for pain were evaluated. There was statistically significant Visual Analogue Scale improvement from preoperative state at post-operative 1wk, 6 months and final follow up were 4.4 ± 1.0, 5.5 ± 1.2 and 5.7 ± 1.3, respectively, p < 0.0001. Oswestery Disability Index improvement from preoperative state at 1week, 6 months and final follow up were 45.8 ± 8.7, 50.4 ± 8.2 and 52.7 ± 10.3, p < 0.0001. MacNab criteria showed excellent outcomes in 17 cases, good outcomes in 11 cases and fair outcomes in 2 cases Sinuvertebral Nerve and Basivertebral Nerve Radiofrequency Ablation is effective in improving the patients’ pain, disability status and patient outcome in our study.

Four-year pain relief after coblation combined with active exercise for cervical discogenic pain: Case report

RATIONALE

Coblation of intervertebral disc is an effective and safe minimally invasive technology for treating discogenic pain. The inactivation of neural ingrowth around annulus and tissue ablation and coagulation are currently considered to be the major causes for success of this treatment. However, it has been found by clinical researchers that its long-term clinical outcome is not optimistic. This report has given us favorable information that this situation can be improved with multimodal therapy.

PATIENT CONCERNS

A 61-year-old man presented with right severe neck and shoulder pain in 2014 which could not be relieved by medications.

DIAGNOSES

According to his symptoms and signs, this patient was diagnosed with cervical discogenic pain. And discography confirmed the diagnosis.

INTERVENTIONS

The patient underwent coblation of cervical intervertebral disc 4-5 (C4-5) and got apparently pain relief after surgery. After 1 month, he began to perform active exercise at least 30 min every day.

OUTCOMES

The right neck and shoulder pain completely relieved for 4 years. The cervical lordosis of this patient was restored in 2018 which was confirmed by MRI compared in 2014 and NDI (neck disability index) decreased from 58 to 10%.

LESSONS

This report demonstrated that it was important and essential for clinicians to educate patients with discogenic pain to perform active exercise after minimally invasive surgery.

A comprehensive review of the sinuvertebral nerve with clinical applications

The anatomy and clinical significance of the sinuvertebral nerve is a topic of considerable interest among anatomists and clinicians, particularly its role in discogenic pain. It has required decades of research to appreciate its role, but not until recently could these studies be compiled to establish a more complete description of its clinical significance. The sinuvertebral nerve is a recurrent nerve that originates from the ventral ramus, re-entering the spinal canal via the intervertebral foramina to innervate multiple meningeal and non-meningeal structures. Its complex anatomy and relationship to discogenic pain have warranted great interest among clinical anatomists owing to its sympathetic contribution to the lumbar spine. Knowledge of the nerve has been used to design a variety of diagnostic and treatment procedures for chronic discogenic pain. This paper reviews the anatomy and clinical aspects of the sinuvertebral nerve.

Percutaneous Transforaminal Endoscopic Radiofrequency Ablation of the Sinuvertebral Nerve in an Olympian with a Left L5 Pedicle/Pars Interarticularis Fracture-Associated Left L5-S1 Disk Desiccation

Background

Irritation of the sinuvertebral nerve by a posterior or posterolateral disk desiccation can cause somatic referred pain that can mimic a lumbar radiculopathy. We present a case of a patient presenting with this condition and the positive result in pain improvement after endoscopic radiofrequency ablation of the sinuvertebral nerve.

Case Description

An 18-year-old Olympic runner presented to our clinic with back pain and left leg pain in a clear L5 distribution. He did not have a history of trauma. His imaging did not demonstrate any lesion causing compression of the left L5 nerve root as expected. He was found to have a left healing L5 pedicle fracture and ipsilateral chronic L5 pars interarticularis fracture. He was also found to have an ipsilateral minor left L5-S1 disk desiccation. His visual analog scale (VAS) score was 7. After a positive provocative diskogram, the patient underwent percutaneous transforaminal endoscopic radiofrequency ablation of the left L5 sinuvertebral nerve, which was irritated by the left L5-S1 disk desiccation. At his 6-month follow-up visit, the patient's VAS score was 1.

Conclusions

It is important for clinicians to remember that back-associated leg pain can be caused by somatic referred pain because of irritation of the sinuvertebral nerve. Endoscopic radiofrequency of this nerve can be beneficial in pain control, but further randomized prospective trials are needed to study these techniques further.