The Anatomy and Physiology of the Vertebral Nerve in Relation to Cervical Migraine

J-A Barré’s historic article “On posterior cervical sympathetic syndrome”: A translation from French

Barré’s 1926 report “Sur un syndrome sympathique cervicale postérieure et sa cause fréquente: l’arthrite cervicale” is arguably the first description of what we now call cervicogenic headache. Barré’s contribution to the subject and significant insights, which have stood the test of time, are insufficiently recognised. This article is an English translation of Barré’s French original.

Headache Relief Is Maintained 7 Years After Anterior Cervical Spine Surgery: Post Hoc Analysis From a Multicenter Randomized Clinical Trial and Cervicogenic Headache Hypothesis

OBJECTIVE

To evaluate whether anterior cervical spine surgery offers sustained (7 years) relief in patients with cervicogenic headaches (CGHs), and evaluate the difference between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) for 1 and 2-level surgeries from a multicenter randomized clinical trial.

METHODS

A post hoc analysis was performed of 575 patients who underwent one or 2-level CDA or ACDF for symptomatic cervical spondylosis as part of a prospective randomized clinical trial. Assessment of pain and functional outcome was done with the Neck Disability Index (NDI) in the trial. We used the NDI headache component to assess headache outcome.

RESULTS

For both 1- and 2-level CDA and ACDF groups, there was significant headache improvement from preoperative baseline out to 7 years (p < 0.0001). For 1-level surgeries, headache improvement was similar for both groups at the 7-year point. For 2-level treatment, CDA patients had significantly improved headache scores versus ACDF patients at the 7-year point (p = 0.016).

CONCLUSION

The headache improvement noted at early follow-up was sustained over the long-term period with ACDF and CDA populations. In the case of 2-level operations, CDA patients demonstrated significantly greater benefit compared to ACDF patients over the long-term. Sinuvertebral nerve irritation at the unco-vasculo-radicular junction and anterior dura may be the cause of CGH. Therefore, it is possible that improved cervical kinematics and preservation of range of motion at adjacent uncovertebral joints in CDA may contribute to the observed difference between the groups.

The vertebral nerve: A comprehensive review of its form and function

The literature is littered with variable and scant reports of the vertebral nerve. The present paper reviews the literature regarding this nervous structure of the neck and attempts to clarify a number of issues surrounding its form, function, and implications of surgical manipulation. The nerve may arise from the stellate ganglion or the ansa subclavia, amongst a number of other structures. Additionally, the terminal insertion of the vertebral nerve varies in the reported literature, with authors observing various terminations. Animal models of the vertebral nerve have limited value, as variations between species and with species have been observed. This review also indicates that contradictory evidence exists regarding the clinical implications of vertebral nerve damage. Although irritation may result in ocular disturbance, hearing loss, headaches, and dizziness, a high degree of incongruity exists around whether or not any clinical findings will actually be observed. Based on our review of the available literature and recent cadaveric research, it appears it may be more logical to classify the vertebral nerve as a variable ramus communicans that connects the stellate or inferior cervical ganglia to the lower cervical spinal nerves and not a structure that ascends entirely with the vertebral artery to enter the cranium.

Comprehensive anatomical and immunohistochemical review of the innervation of the human spine and joints with application to an improved understanding of back pain

BACKGROUND

Pain of spinal origin contributes significantly to cervical, thoracic, and lower back pain presentations. Such pain originates in the nerve fibers supplying the joints or the surrounding ligaments and intervertebral discs. Although there has been little detailed discussion of spinal bony innervation patterns in the literature, the clinical implications of these patterns are anatomically and medically significant.

METHODS

The present review provides a detailed analysis of the innervation of the spine, identifying the unique features of each part via online search engines.

CONCLUSIONS

The clinical implications of these various studies lie in the importance of the innervation patterns for the mechanism of spinal pain. Immunohistochemical studies have provided further evidence regarding the nature of the innervation of the spine.

Functional anatomy of the spine

Among other important features of the functional anatomy of the spine, described in this chapter, is the remarkable difference between the design and function of the cervical spine and that of the lumbar spine. In the cervical spine, the atlas serves to transmit the load of the head to the typical cervical vertebrae. The axis adapts the suboccipital region to the typical cervical spine. In cervical intervertebrtal discs the anulus fibrosus is not circumferential but is crescentic, and serves as an interosseous ligament in the saddle joint between vertebral bodies. Cervical vertebrae rotate and translate in the sagittal plane, and rotate in the manner of an inverted cone, across an oblique coronal plane. The cervical zygapophysial joints are the most common source of chronic neck pain. By contrast, lumbar discs are well designed to sustain compression loads, but rely on posterior elements to limit axial rotation. Internal disc disruption is the most common basis for chronic low-back pain. Spinal muscles are arranged systematically in prevertebral and postvertebral groups. The intrinsic elements of the spine are innervated by the dorsal rami of the spinal nerves, and by the sinuvertebral nerves. Little modern research has been conducted into the structure of the thoracic spine, or the causes of thoracic spinal pain.

The anatomy and pathophysiology of neck pain

Neck pain should not, and must not, be confused with cervical radicular pain. Equating the two conditions, or confusing them, results in misdiagnosis, inappropriate investigations, and inappropriate treatment that is destined to fail. So critical is the difference that pedagogically it is unwise to include the two topics in the same book, let alone the same article. However, traditions and expectations are hard to break. In deference to habit, this article addresses both entities, but does so by underplaying cervical radicular pain so as to retain the emphasis on neck pain.

Cervicogenic headache: an assessment of the evidence on clinical diagnosis, invasive tests, and treatment

Cervicogenic headache is characterised by pain referred to the head from the cervical spine. Although the International Headache Society recognises this type of headache as a distinct disorder, some clinicians remain sceptical. Laboratory and clinical studies have shown that pain from upper cervical joints and muscles can be referred to the head. Clinical diagnostic criteria have not proved valid, but a cervical source of pain can be established by use of fluoroscopically guided, controlled, diagnostic nerve blocks. In this Review, we outline the basic science and clinical evidence for cervicogenic headache and indicate how opposing approaches to its definition and diagnosis affect the evidence for its clinical management. We provide recommendations that enable a pragmatic approach to the diagnosis and management of probable cervicogenic headache, as well as a rigorous approach to the diagnosis and management of definite cervical headache.

The lateral atlanto-axial joint as a source of headache in congenital atlanto-occipital fusion

A 47-yr-old woman presented with severe right-sided neck pain and headache, predominantly in the right-occipital region, for 3 yrs. The symptoms persisted despite using nonsteroidal antiinflammatory medications and undergoing physical therapy. The patient's examination was unremarkable except for reduced neck motion and prominent right-occipital tenderness. Imaging showed congenital fusion of the atlanto-occipital joints bilaterally. A fluoroscopically guided diagnostic right-lateral atlanto-axial joint injection was positive. We are reporting the first case of clinically proven lateral atlanto-axial joint arthropathy with neck pain and headache in a patient with congenital atlanto-occipital joint fusion. Subsequently, the patient received a set of two therapeutic lateral atlanto-axial joint injections. She had remarkable improvement of her headache and neck pain. At 1-yr follow-up, the patient continued to have significant improvement of the right-sided neck pain and headache.

The vertebral nerve revisited

There is significant paucity in the literature regarding the vertebral nerve. Moreover, descriptions of this structure are conflicting. To evaluate further the anatomy and potential clinical significance of this structure, 10 fresh adult cadavers (20 sides) underwent dissection and macroscopic observation of this structure. All specimens were found to have a vertebral nerve that originated from the stellate ganglion with the exception of two left sides (10%) in which this nerve arose from the inferior cervical ganglion. This nerve ascended posteromedial to the vertebral artery. The vertebral nerve was found to be, in essence, a long and deep gray ramus communicans that connected most commonly the stellate ganglia to C6 or C7 spinal nerves by passing through the C6 and C7 transverse foramina. Fifteen percent of sides were found to have a vertebral nerve that was plexiform in its configuration. Fifty percent were found to have very small branches that entered the fibrous capsule of adjacent zygapophyseal and intervertebral joints. Some specimens were noted to have meningeal branches of the vertebral nerve. Based on our observations, the vertebral nerve is simply a deep ramus communicans, which often provides articular and meningeal branches to the adjacent spine. As neck pain is a significant reason for physician office visits, additional knowledge of the nerves innervating the joints and adjacent meninges of the neck could be important for both surgical and medical blockade of nerve fibers.

The sensory and sympathetic nerve supply within the cervical spine: review of recent observations

The purpose of this review is to identify recently observed features of the sympathetic and sensory systems and their pathways which characterize cervical spine innervation and their potential relevance to the clinical pain syndromes. The results of studies examining the innervation patterns of the zygoapophysial joints serve to demonstrate that structures in the cervical spine, as in other spinal regions, are partly innervated by sensory nerves traveling along sympathetic pathways. These studies also demonstrate that the neuropeptide levels in the cell bodies located within the dorsal root ganglion of these sensory nerves fluctuate according to the physiological state of the zygoapophysial joint. Additional to the sympathetic nerves accompanying the vertebral artery, the innervation patterns of dura and posterior longitudinal ligament in the upper cervical spine are distinctive features of cervical spine innervation. The possible clinical implications of cervical innervation patterns are considered with reference to referred pain, the pain patterns associated with a dissecting vertebral artery and cervicogenic headaches.

The neck and headaches

Referred pain from disorders of the cervical spine can be perceived as headache. The mechanism is convergence between trigeminal afferents and afferents of the upper three cervical nerves in the trigeminocervical nucleus. Cervicogenic headache cannot be diagnosed on clinical grounds alone. The definitive criterion is complete relief of pain after controlled diagnostic blocks of cervical structures or their nerve supply. The most rigorously studied example of cervicogenic headache is third occipital headache.

The anatomy and pathophysiology of neck pain

This article carefully itemizes the various anatomic structures that can evoke neck pain, putting in perspective what clinicians know, what they assume, and what they need to understand better about neck pain and pain referred from the neck. The critique of many of the accepted entities in the differential diagnosis of neck pain is crucial to an understanding of the causes of neck pain and an ability to implement appropriate therapies.

Color Doppler sonography of orbital and vertebral arteries in migraineurs without aura

PURPOSE

The objective of this study was to investigate whether the retrobulbar hemodynamics in the ophthalmic (OA), posterior ciliary (PCA), central retinal (CRA), and vertebral (VA) arteries are affected in migraineurs without aura.

METHODS

The eyes of migraineurs without aura and those of healthy control subjects were evaluated during both headache and headache-free periods. Retrobulbar and vertebral blood flow velocities in the OA, PCA, CRA, and the extracranial part of the VA were measured bilaterally using color Doppler sonography. The peak systolic and end-diastolic flow velocities and the pulsatility (PI) and resistance (RI) indices were determined for all arteries.

RESULTS

In total, we enrolled 30 migraineurs and 31 healthy control subjects. Statistically significant differences between headache-free migraineurs and control subjects were observed in the PI and RI of both right and left PCAs and in the RI of both right and left CRAs. The PI and RI of the left VA of the migraineurs were significantly lower during both headache and headache-free periods than were those of the control subjects. Among the migraineurs, the peak systolic and end-diastolic velocities of the left VA were increased during headache periods relative to those found during the headache-free periods.

CONCLUSIONS

The retrobulbar circulation and flow hemodynamics in the left VA may be altered in both headache and headache-free periods in migraineurs without aura. The differences found between migraineurs and control subjects may implicate autonomic dysfunction in migraineurs.

Cervicogenic headache: anatomic basis and pathophysiologic mechanisms

Cervicogenic headache is pain perceived in the head but referred from a primary source in the cervical spine. The physiologic basis for this pain is convergence between trigeminal afferents and afferents from the upper three cervical spinal nerves. The possible sources of cervicogenic headache lie in the structures innervated by the C1 to C3 spinal nerves, and include the upper cervical synovial joints, the upper cervical muscles, the C2-3 disc, the vertebral and internal carotid arteries, and the dura mater of the upper spinal cord and posterior cranial fossa. Experiments in normal volunteers have established that the cervical muscles and joints can be sources of headache.

Treatment of severe glaucomatous visual field deficit by chiropractic spinal manipulative therapy: a prospective case study and discussion

OBJECTIVE

To discuss the case of a patient with severely reduced visual fields arising from terminal glaucomatous retinal damage and the treatment of this condition by spinal manipulation.

CLINICAL FEATURES

A 25-year-old uniocular female patient with congenital glaucoma sought chiropractic treatment for spinal pain, headache, and classic migraine. Advanced optic disk cupping was present, and loss of vision was near complete. A 3-degree island of central vision and a small area of peripheral light sensitivity had remained relatively stable for 3 years after a trabeculectomy procedure that had resulted in intraocular hypotony.

INTERVENTION AND OUTCOME

It was considered possible that chiropractic spinal manipulative therapy may have a positive outcome in visual performance. Before commencing chiropractic spinal manipulative therapy, an ophthalmologic examination was performed, and visual performance was monitored through a course of treatment. Immediately after the first treatment, significant visual field improvement was recorded in the remaining eye. Maximal improvement of vision was achieved after 1 week (4 treatment sessions). Total monocular visual field had increased from approximately 2% to approximately 20% of normal. Corrected central acuity had improved from 6/12 to 6/9. Independent reexamination by the patient's regular ophthalmic surgeon confirmed the results.

CONCLUSION

Recovery of vision in this patient was an unexpected and remarkable outcome, raising the question of whether chiropractic spinal manipulative therapy may be of value in the management of glaucomatous visual field loss. More intensive research is required.

Autoregulation in the middle meningeal artery

In cats anesthetized with alpha-chloralose, autoregulation of blood flow (F) in the middle meningeal and common carotid arteries was assessed by bleeding and subsequently reinfusing the animals to achieve a 25% step reduction in mean arterial blood pressure (P), while maintaining the systolic blood pressure >80 mmHg. The integrity of autoregulation was assessed by calculating the gain factor Gf = 1 - [(deltaF/F)/(deltaP/P)]. Cats were examined intact, after hexamethonium (10 mg/kg), and after papaverine (6 mg/kg). Reduction of blood pressure of 25 to 60 mmHg produced equivalent drops in carotid blood flow (Gf = 0.041 +/- 0.34; mean +/- standard deviation, n = 12). There were only small changes in flow in the middle meningeal artery during this procedure (Gf = 0.91 +/- 0.29). Hexamethonium did not block autoregulation in the middle meningeal artery (Gf = 0.92 +/- 0.13, n = 4). However, papaverine almost completely abolished the ability of the artery to autoregulate (Gf = 0.10 +/- 0.16, n = 7). The results suggest that the middle meningeal artery possesses an ability similar to that of the cortical circulation to autoregulate its blood flow through intrinsic, non-neuronal mechanisms. This will have important implications for the study of disturbances of dural arterial control in migraine and other headaches.

Anatomy and physiology of headache

Headache is a vast field with many different varieties of headaches and classifications. However, all headaches have a common anatomy and physiology. All headaches are mediated by the trigeminocervical nucleus, and are initiated by noxious stimulation of the endings of the nerves that synapse on this nucleus, by irritation of the nerves themselves, or by disinhibition of the nucleus. A mastery of the relevant anatomy and physiology of the trigeminocervical nociceptive system serves to predict and summarise the many varieties of headache systematically and with reference to their mechanisms.

The anatomy and pathophysiology of whiplash

Whereas the symptoms of whiplash injury are frequently poorly understood or misrepresented as due to neurosis, a review of the literature reveals a considerable amount of biomechanical and experimental data that substantiate a diverse organic basis for these symptoms, including disorders commonly not considered or sought for in the investigation of whiplash. Moreover, formal studies fail to substantiate the notion of 'litigation neurosis' being the cause of prolonged symptoms. This review synthesises the anatomy and pathology of whiplash, and the pathophysiology of symptoms, into what can be construed as the organic basis for whiplash.

Low pharmacological responsiveness of the vertebro-basilar circulation in Macaca nemestrina monkeys

We have examined the responsiveness of the vertebro-basilar circulation of the anesthetized Macaca nemestrina monkey to vasoactive agents infused directly into the artery. Infusion of noradrenaline caused a slight increase in vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or external carotid arteries. In the presence of vasodilatation caused by inhalation of a CO2-rich gas mixture, this constriction became a dilatation. Serotonin was without significant effect on the vertebral arterial bed. Bradykinin, histamine and prostaglandin E1 all produced slight dilatation, with bradykinin being the most potent. In all cases the concentration required to produce an effect on the vasculature was much greater in the vertebral circulation than it is in the internal carotid and extracerebral circulations. We conclude that the intact vertebro-basilar circulation is much less sensitive to vasoactive agents than experiments with isolated segments of these arteries would indicate and that therefore these agents are unlikely to play a significant part in the pathogenesis of vertebro-basilar migraine.

Tolfenamic acid and caffeine: a useful combination in migraine

Tolfenamic acid is a potent inhibitor of prostaglandin biosynthesis, which has been proved effective in the treatment of acute migraine attacks. The usefulness of caffeine, metoclopramide and pyridoxine as adjuncts to tolfenamic acid was tested in acute migraine attacks in ten patients. A combination of tolfenamic acid (200 mg) with either caffeine (100 mg), metoclopramide (10 mg) or pyridoxine (300 mg) was given twice to each patient in random order. Thus 60 attacks were treated. The tolfenamic acid-caffeine combination proved the most effective as judged by duration and intensity of attacks, working ability, vigilance, and overall evaluation of the drugs by the patients. Metoclopramide was somewhat better than pyridoxine as an additive.