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

Atypical cervical spondylotic radiculopathy resulting in a hypertensive emergency during cervical extension: A case report and review of literature

BACKGROUND

Extensive research revealed the absence of reports documenting hypertensive emergencies precipitated by changes in the cervical spine posture.

CASE SUMMARY

We here present a 57-year-old woman diagnosed as having cervical spondylotic radiculopathy (CSR) who was scheduled for anterior cervical decompression and fusion. During post-anesthetic positioning, a sudden hypertensive surge was observed when the patient was in a supine position with the neck being slightly extended. This surge was promptly reversed through cervical flexion and head elevation. This event however required an alternate surgical approach for recovery—posterior laminoplasty and endoscopy-assisted nucleus pulposus removal. Following the 6-month outpatient follow-up period, cervical flexion and extension activities substantially improved in the patient without any episodes of increase in acute blood pressure.

CONCLUSION

Maintaining a safe hypotensive posture and performing rapid, thorough decompression surgery may serve as effective interventions for patients presenting symptoms similar to those of CSR accompanied by hypertensive emergencies (HE). This would mitigate the underlying causes of these HEs.

Mid-term clinical effect of resecting posterior longitudinal ligament in anterior approach for cervical spondylosis with sympathetic symptoms: retrospective cohort analysis

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

The purpose of this study is to investigate whether the removal of the posterior longitudinal ligament (PLL) affects the mid-term outcome of anterior cervical fusion for cervical spondylosis with sympathetic symptoms(CSSS).

METHODS

From January 2012 to July 2013, 66 patients who were diagnosed with CSSS with ≥ 10-year follow-up at our institution were assessed. All patients were divided into two groups: Group A (36 cases) in which patients underwent anterior cervical fusion with PLL resection and Group B (30 cases) in which patients underwent anterior cervical fusion without PLL resection. The sympathetic symptom 20-point system was used to evaluate the sympathetic symptoms, such as tinnitus, headache and vertigo, etc. And the neurological status was assessed by the Japanese Orthopedic Association (JOA) scores. Clinical and radiologic data were evaluated preoperatively, 9 days, 3 months, 6 months, 12 months, 24 months, 60 months, and 120 months postoperatively. Data collected included all perioperative complications as morbidities that occurred during the period of follow-up.

RESULTS

The postoperative JOA scores and 20-point score can be significantly improved compared with preoperative whether the PLL is removed in both groups. However, the postoperative 20-point score of patients in group A was significantly different from that in group B. No loosening and displacement of prosthesis occurred.

CONCLUSION

A better clinical effect could be attained when resecting the PLL in the operation. The PLL may play an important role in CSSS. The mid-term outcomes of anterior cervical fusion with PLL resection were satisfied in treating CSSS.

Anterior cervical discectomy and fusion is more effective than cervical arthroplasty in relieving atypical symptoms in patients with cervical spondylosis

BACKGROUND AND PURPOSE

Patients with cervical spondylosis often present with concurrent 'atypical symptoms' of unknown etiology that have been associated with cervical spondylotic disease, including dizziness, headache, nausea, tinnitus, blurred vision, palpitations, and memory and gastrointestinal disturbances. Few studies have addressed whether surgical intervention to treat classic symptoms of cervical spondylosis can also effectively alleviate atypical symptoms. Accordingly, the purpose of this study is to compare the ability of cervical arthroplasty (CA) and anterior cervical discectomy and fusion (ACDF) to alleviate atypical symptoms associated with cervical spondylosis.

MATERIALS AND METHODS

A retrospective analysis of 140 patients with cervical spondylosis and associated atypical symptoms was performed. Atypical symptoms were defined vertigo, headache, nausea and vomiting, tinnitus, blur vision, palpitation, hypomnesia, and gastroenteric disturbances not otherwise explained by medical comorbidities. Seventy-eight patients (55.7%) underwent ACDF and 62 (44.3%) patients underwent CA. Demographics, surgical characteristics, patient reported outcome measures (PROMs), radiographs, complication rates, and resolution in atypical symptoms were recorded and compared between groups. Atypical symptoms were assessed using a 20-point system. All the patients had a minimum of five years follow-up.

RESULTS

VAS, SF-36, JOA, and NDI scores improved significantly in all the patients (p < 0.001). At the last follow-up, the fusion rate was 97% in the ACDF group. Atypical symptoms improved in both groups (p < 0.001), although the ACDF group demonstrated greater improvement in headache and vertigo resolution compared to the CA group (p < 0.0001).

CONCLUSIONS

While both ACDF and CA are effective in alleviating atypical symptoms associated with cervical spondylosis, ACDF demonstrated greater improvements in atypical symptoms.

Intraoperative hypotension in non-emergency decompression surgery for cervical spondylosis: The role of chronic arterial hypertension

Background

Cervical spondylotic myelopathy and chronic hypertension show a cause-effect relationship. Hypertension increases cardiovascular risk and is associated with intraoperative hypotension. We aimed to evaluate intraoperative hypotension in patients undergoing non-emergency decompression surgery for cervical spondylosis and its association with clinical myelopathy and chronic arterial hypertension.

Methods

This retrospective cohort study used healthcare data of adult patients undergoing cervical spine surgeries at Taipei Veterans General Hospital from 2015 to 2019. The primary outcomes were the incidence of intraoperative hypotension and predictive factors, and the secondary outcomes were the association of intraoperative hypotension and postoperative adverse outcomes in the surgical population.

Results

Among the 1833 patients analyzed, 795 (43.4%) required vasopressor treatment and 342 (18.7%) showed persistent hypotension. Factors independent associated with hypotension after anesthetic induction were age [odds ratio (OR), 1.15; 95% confidence interval (CI), 1.07-1.23 per 5 years, P < 0.001], male sex (OR, 1.63; 95% CI, 1.21-2.19, P < 0.001), chronic hypertension (OR, 1.77; 95% CI, 1.32-2.38, P < 0.001), upper cervical spine level C0-2 treated (OR, 3.04; 95% CI, 1.92-4.84, P < 0.001 vs. C3-T1), and increased number of spine segments treated (OR, 1.43; 95% CI 1.26-1.63, P < 0.001). Patients who developed intraoperative hypotension experienced more acute postoperative kidney injury (OR, 7.90; 95% CI, 2.34–26.63, P < 0.001), greater need for intensive care (OR, 1.80; 95% CI, 1.24–2.60, P = 0.002), and longer admission after surgery (1.09 days longer, 95% CI 0.06-2.12, P = 0.038).

Conclusion

Intraoperative hypotension is common even in non-emergency cervical spine surgery. A history of hypertension independently predicted intraoperative hypotension. Prompt assessments for identifiable features can help ameliorate intraoperative hypotension.

Surgical Decompression for Cervical Spondylotic Myelopathy in Patients with Associated Hypertension: A Single-Center Retrospective Cohort and Systematic Review of the Literature

OBJECTIVE

To explore the relationship between spinal cord compression and hypertension through analysis of blood pressure (BP) variations in a cervical spondylotic myelopathy (CSM) cohort after surgical decompression, along with a review of the literature.

METHODS

A single-institution retrospective review of patients with CSM who underwent cervical decompression between 2016 and 2017 was conducted. Baseline clinical and imaging characteristics, preoperative and postoperative BP readings, heart rate, functional status, and pain scores were collected. In addition, a PRISMA guidelines-based systematic review was performed.

RESULTS

We identified 264 patients with CSM treated surgically; 149 (56.4%) of these had hypertension. The degree of spinal canal compromise and spinal cord compression, preoperative neurologic examination, and the presence of T2-signal hyperintensity on magnetic resonance imaging were associated with hypertension. Overall mean arterial pressure (MAP) decreased significantly at 1 and 12 months after surgery. Patients without T2-signal hyperintensity on imaging showed a MAP reduction at 12 months postoperatively, whereas those with T2-signal hyperintensity showed a transient MAP reduction at 1 month postoperatively before returning to preoperative values. At 12 months after surgery, 24 of 97 patients (24.7%) with initially uncontrolled hypertension had controlled BP values with significant reduction of MAP, systolic BP, and diastolic BP. Including the present study, 5 articles were eligible for systematic review, with all reporting a BP decrease in patients with CSM after decompression.

CONCLUSIONS

Analysis of our retrospective cohort and a systematic review suggest that cervical surgical decompression reduces BP in some patients with CSM. However, this improvement is less apparent in patients with preoperative spinal cord T2-signal hyperintensity.

Refractory Syncope and Presyncope Associated with Atlantoaxial Instability: Preliminary Evidence of Improvement Following Surgical Stabilization

BACKGROUND

The proclivity to atlantoaxial instability (AAI) has been widely reported for conditions such as rheumatoid arthritis and Down syndrome. Similarly, we have found a higher than expected incidence of AAI in hereditary connective tissue disorders. We demonstrate a strong association of AAI with manifestations of dysautonomia, in particular syncope and lightheadedness, and make preliminary observations as to the salutary effect of surgical stabilization of the atlantoaxial motion segment.

METHODS

In an institutional review board-approved retrospective study, 20 subjects (16 women, 4 men) with hereditary connective tissue disorders had AAI diagnosed by computed tomography. Subjects underwent realignment (reduction), stabilization, and fusion of the C1-C2 motion segment. All subjects completed preoperative and postoperative questionnaires in which they were asked about performance, function, and autonomic symptoms, including lightheadedness, presyncope, and syncope.

RESULTS

All patients with AAI reported lightheadedness, and 15 had refractory syncope or presyncope despite maximal medical management and physical therapy. Postoperatively, subjects reported a statistically significant improvement in lightheadedness (P = 0.003), presyncope (P = 0.006), and syncope (P = 0.03), and in the frequency (P < 0.05) of other symptoms related to autonomic function, such as nausea, exercise intolerance, palpitations, tremors, heat intolerance, gastroesophageal reflux, and sleep apnea.

CONCLUSIONS

This study draws attention to the potential for AAI to present with syncope or presyncope that is refractory to medical management, and for surgical stabilization of AAI to lead to improvement of these and other autonomic symptoms.

Histologic Observation and Significance of Sympathetic Nerve Fiber Distribution on Human Cervical Ligamentum Flavum

Objective

To study the distribution of sympathetic nerves of the ligamentum flavum (LF), confirm its existence by histological observation and nuclear magnetic resonance spectroscopy, and analyze the relationship between sympathetic nerve fibers and the biomechanical structure of the LF.

Methods

Randomly controlled scientific research selected 15 cases of posterior surgery in the affiliated hospital of Qingdao University from January 2013 to December 2019. The average age was 67.5 ± 14.5 years old, eight males and seven females. The LF specimens (completely separated fresh tissue) of different segments (C_3‐7) were taken during the operation. Two pages of LF specimens on the left and right sides of the same segment are randomly allocated by the pairing method for formalin fixation and cryopreservation in liquid nitrogen. LF specimens extracted from seven other adult cadaver specimens (average age at death of about 56.8 ± 4.0 years, three males and four females) were used as a control group; together with formalin‐ fixed specimens obtained during surgery, 3D slices were given layer by layer. The distribution of sympathetic nerves in different parts of the LF was analyzed by glyoxylic acid‐induced biological monoamine fluorescent technique (SPG) and hematoxylin–eosin (HE) staining. Fifteen liquid nitrogen storage specimens were divided into the back of the LF and the spinal canal through frozen sections, and were analyzed by nuclear magnetic resonance spectroscopy‐hydrogen spectrum (¹H ‐NMR) for neurotransmitters and neurometabolites.

Results

There were type C sympathetic nerve fibers in the LF, which were divided into linear shape (α) and wave shape (β). Experimental group (χ² = 1.705, P > 0.05) and control group (χ² = 0.879, P > 0.05) can detect no difference in fluorescence units. Nerve fiber transmitter metabolites choline (Cho), creator (Cr), γ‐aminobutyric acid (GABA) also indicate that the sympathetic nerve is present in the LF. LF sympathetic nerve fibers were mainly distributed in the proximal spinal canal surface, nerve fibers on the medial belt (area II) were fewer than the lateral belt (area I) (W = 210, P < 0.05). The ¹HNMR spectrum of LF spinal canal PG / Cho (t = 8.721, P < 0.05), GABA (t = 16.01, P < 0.05) value increased, lactic acid (Lac) / Cr (t = 4.213, P < 0.05), Cho / Cr (t = 2.402, P < 0.05) value decreased, indicating that nerve fibers are actively metabolized on the surface of the spinal canal, mainly distributed in tube surface. βtype fibers were more often distributed around microvessels. A small amount of α type fibers went next to the vascular structures, while α type fibers and β type fibers go cross within LF. Two patients with vertebral artery dissection had no recurrence of sympathetic symptoms within a total of 12 follow‐ups 2 years after discharge.

Conclusions

There are many sympathetic nerve fibers distributed on LF, and their distribution may be correlated with histological and mechanical characteristics of LF. It may also be the anatomical basis of cervical vertigo.

Anatomy and Ultrasound-Guided Injection of the Medial Branch of the Dorsal Ramus of the Cervical Spinal Nerves in the Horse: A Cadaveric Study

OBJECTIVE

 The aim of this study was to describe the anatomy of the nerves supplying the cervical articular process joint and to identify relevant anatomical landmarks that could aid in the ultrasound-guided location and injection of these nerves for diagnostic and therapeutic purposes.

STUDY DESIGN

 Twelve cadaveric equine necks were used. Five necks were dissected to study the anatomy of the medial branch of the dorsal ramus of the cervical spinal nerves 3 to 7. Relevant anatomical findings detected during dissections were combined with ultrasonographic images obtained in one other neck. Six additional necks were used to assess the accuracy of ultrasound-guided injections of the medial branch with blue dye.

RESULTS

 Each examined cervical articular process joint, except for C2 to C3, presented a dual nerve supply. The articular process joints were found to be in close anatomical relationship with the medial branch of the dorsal ramus of the cervical spinal nerve exiting from the intervertebral foramen at the same level, and with the medial branch of the dorsal ramus of the cervical spinal nerve exiting from the intervertebral foramen one level cranial to the articular process joint of interest. A total of 55 nerves were injected under ultrasonographic guidance, 51 of which were successfully stained.

CONCLUSION

 The current study provided new detailed information regarding the innervation of the cervical articular process joint. The medial branches of the dorsal rami of the cervical spinal nerves were injected with an accuracy that would be of clinical value. Our study offers the foundations to develop new diagnostic and therapeutic techniques for pain management in cervical articular process joint arthropathy in horses.

The effectiveness of anterior cervical decompression and fusion for the relief of dizziness in patients with cervical spondylosis: a multicentre prospective cohort study

AIMS

Cervical spondylosis is often accompanied by dizziness. It has recently been shown that the ingrowth of Ruffini corpuscles into diseased cervical discs may be related to cervicogenic dizziness. In order to evaluate whether cervicogenic dizziness stems from the diseased cervical disc, we performed a prospective cohort study to assess the effectiveness of anterior cervical discectomy and fusion on the relief of dizziness.

PATIENTS AND METHODS

Of 145 patients with cervical spondylosis and dizziness, 116 underwent anterior cervical decompression and fusion and 29 underwent conservative treatment. All were followed up for one year. The primary outcomes were measures of the intensity and frequency of dizziness. Secondary outcomes were changes in the modified Japanese Orthopaedic Association (mJOA) score and a visual analogue scale score for neck pain.

RESULTS

There were significantly lower scores for the intensity and frequency of dizziness in the surgical group compared with the conservative group at different time points during the one-year follow-up period (p = 0.001). There was a significant improvement in mJOA scores in the surgical group.

CONCLUSION

This study indicates that anterior cervical surgery can relieve dizziness in patients with cervical spondylosis and that dizziness is an accompanying manifestation of cervical spondylosis. Cite this article: Bone Joint J 2018;100-B:81-7.

Computer simulation of lumbar flexion shows shear of the facet capsular ligament

BACKGROUND CONTEXT

The lumbar facet capsular ligament (FCL) is a posterior spinal ligament with a complex structure and kinematic profile. The FCL has a curved geometry, multiple attachment sites, and preferentially aligned collagen fiber bundles on the posterior surface that are innervated with mechanoreceptive nerve endings. Spinal flexion induces three-dimensional (3D) deformations, requiring the FCL to maintain significant tensile and shear loads. Previous works aimed to study 3D facet joint kinematics during flexion, but to our knowledge none have reported localized FCL surface deformations likely created by this complex structure.

PURPOSE

The purpose of this study was to elucidate local deformations of both the posterior and anterior surfaces of the lumbar FCL to understand the distribution and magnitude of in-plane and through-plane deformations, including the prevalence of shear.

STUDY DESIGN/SETTING

The FCL anterior and posterior surface deformations were quantified through creation of a finite element model simulating facet joint flexion using a realistic geometry, physiological kinematics, and fitted constitutive material.

METHODS

Geometry was obtained from the micro-CT data of a healthy L3-L4 facet joint capsule (n=1); kinematics were extracted from sagittal plane fluoroscopic data of healthy volunteers (n=10) performing flexion; and average material properties were determined from planar biaxial extension tests of L4-L5 FCLs (n=6). All analyses were performed with the non-linear finite element solver, FEBio. A grid of equally spaced 3×3 nodes on the posterior surface identified regional differences within the strain fields and was used to create comparisons against previously published experimental data. This study was funded by the National Institutes of Health and the authors have no disclosures.

RESULTS

Inhomogeneous in-plane and through-plane shear deformations were prominent through the middle body of the FCL on both surfaces. Anterior surface deformations were more pronounced because of the small width of the joint space, whereas posterior surface deformations were more diffuse because the larger area increased deformability. We speculate these areas of large deformation may provide this proprioceptive system with an excellent measure of spinal motion.

CONCLUSIONS

We found that in-plane and through-plane shear deformations are widely present in finite element simulations of a lumbar FCL during flexion. Importantly, we conclude that future studies of the FCL must consider the effects of both shear and tensile deformations.

Planar biaxial extension of the lumbar facet capsular ligament reveals significant in-plane shear forces

The lumbar facet capsular ligament (FCL) articulates with six degrees of freedom during spinal motions of flexion/extension, lateral bending, and axial rotation. The lumbar FCL is composed of highly aligned collagen fiber bundles on the posterior surface (oriented primarily laterally between the rigid articular facets) and irregularly oriented elastin on the anterior surface. Because the FCL is a capsule, it has multiple insertion sites across the lumbar facet joint, which, along with its material structure, give rise to complicated deformations in vivo. We performed planar equibiaxial mechanical tests on excised healthy cadaveric lumbar FCLs (n=6) to extract normal and shear reaction forces, and fit sample-specific two-fiber-family finite element models to the experimental force data. An eight-parameter anisotropic, hyperelastic model was used. Shear forces at maximum extension (mean values of 1.68N and 3.01N in the two directions) were of comparable magnitude to the normal forces perpendicular to the aligned collagen fiber bundles (4.67N) but smaller than normal forces in the fiber direction (16.11N). Inclusion of the experimental shear forces in the model optimization yielded fits with highly aligned fibers oriented at a specific angle across all samples, typically with one fiber population aligned nearly horizontally and the other at an oblique angle. Conversely, models fit to only the normal force data resulted in a broad range of fiber angles with low specificity. We found that shear forces generated through planar equibiaxial extension aided the model fit in describing the anisotropic nature of the FCL surface.

Mid-term Outcomes of Anterior Cervical Fusion for Cervical Spondylosis With Sympathetic Symptoms

STUDY DESIGN

Prospective study.

OBJECTIVE

The purpose of this study is to elucidate mid-term outcomes of anterior cervical fusion for cervical spondylosis with sympathetic symptoms (CSSS).

SUMMARY OF BACKGROUND DATE

The terminology, pathogenesis, diagnosis, and treatment of CSSS remain controversial. Surgical treatment of CSSS has been rarely reported. This is the first prospective study to evaluate the mid-term outcome of surgical treatment of CSSS.

METHODS

Thirty-one patients who were diagnosed with CSSS in 2006 were evaluated prospectively. All patients were assigned to undergo anterior cervical fusion with posterior longitudinal ligament (PLL) resection and followed up for ≥5 years. Sympathetic symptoms such as vertigo, headache, and tinnitus, etc. were evaluated using the sympathetic symptom 20-point score. Neurological status was assessed using the Japanese Orthopedic Association (JOA) score. Clinical and radiologic data were prospectively collected before surgery, and at 1 week, 2 months, 6 months, 2 years, and 5 years after surgery. Surgical complications and morbidities of other diseases during the follow-up were also recorded.

RESULTS

The mean 20-point score decreased significantly from 7.3±3.5 before surgery to 2.2±2.7 at the final follow-up (P<0.001), giving a mean recovery rate of 66.1%±50.3%. Good to excellent results were attained in 80.6% of these patients. The sympathetic symptoms were relieved in 23 of the 31 patients in the early postoperative period, and 5 patients in 2 months. No relief of sympathetic symptoms was found in 3 patients. The mean JOA score improved significantly from 12.0±1.9 before surgery to 14.8±1.5 by the end of the follow-up (P<0.001). No late neurological deterioration was found in this group.

CONCLUSIONS

The mid-term outcomes of anterior cervical fusion with PLL resection for CSSS have been satisfactory. Differential diagnosis before surgery is of great importance. PLL may play a role in presenting sympathetic symptoms.

Effect of double-door laminoplasty on atypical symptoms associated with cervical spondylotic myelopathy/radiculopathy

BACKGROUND

Double-door laminoplasty is an effective method in treating patients with cervical spondylosis. Many patients with cervical spondylosis experience a set of atypical symptoms such as vertigo and tinnitus, and wish to know if the surgical treatment for cervical spondylosis can also alleviate those symptoms. The current research was carried out to investigate if atypical symptoms can be alleviated in patients who received laminoplasty for the treatment of cervical spondylosis.

METHODS

One hundred ninety patients who received laminoplasty to treat cervical spondylotic myelopathy/radiculopathy in our center and complained about one or more of the atypical symptoms before the surgery were followed for a mean of 61.9 months (from 39 to 87 months) after the surgery. Severity scores were retrospectively collected by follow up outpatient visits or phone interviews. The data was calculated based on patient feedback on the frequency and severity of those symptoms before the surgery and at last follow up, and were compared by paired sample t-tests.

RESULTS

Most patients reported that the atypical symptoms such as vertigo (P <0.001), nausea (P <0.001), headache (P <0.001), tinnitus (P = 0.001), blur vision (P = 0.005), palpitation (P <0.001) and gastrointestinal discomfort (P = 0.001) were significantly alleviated at the last follow up; there was no significant change in the severity of hypomnesia (P = 0.675).

CONCLUSION

Double-door laminoplasty can significantly alleviate most of the atypical symptoms in patients with cervical spondylosis. Further research is needed to explore mechanisms underlying this extra benefit of laminoplasty.

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.

Effect of different surgical methods on headache associated with cervical spondylotic myelopathy and/or radiculopathy

BACKGROUND

Anterior cervical discectomy and fusion, total disk replacement and open door laminoplasty have been widely used to treat patients with cervical spondylotic myelopathy and/or radiculopathy. In our clinical practice, many patients with cervical spondylosis also complain of headache, and wish to know if the surgical treatment for cervical spondylosis can also alleviate this symptom. Considering that there is no literature concerning this extra benefit of surgical manipulation on cervical spondylosis, we have carried out this retrospective study.

METHODS

Among the patients treated with anterior cervical discectomy and fusion, total disk replacement and open door laminoplasty in our institute for cervical spondylotic myelopathy and/or radiculopathy between February 2002 to March 2011, 108 of whom that have complained about headache at the same time were included in this study. Those patients were followed by 25 to 145 months. Severity of headache before the surgery and at the last follow up was recorded by VAS pain scores and compared among the patients with different surgical methods using SPSS17.0 software. One way ANOVA was used to compare VAS scores between the groups, paired sample t-tests were used to compare the differences in a group at different time points.

RESULTS

Headache was significantly alleviated in all groups (P < 0.01). Respectively, 75.0% of the patients in the ACDF group, 84.6% of the patients in the TDR group and 82.2% of the patients in the laminoplasty group were significantly relieved of the headache after the surgery. No significant differences were found with the VAS score at the last follow up among the groups (P > 0.05). No significant differences were found among the groups comparing the degree of alleviation of VAS scores before and after the surgery (P > 0.05).

DISCUSSION

Considering that all the three procedures in the current study have achieved similar effect on alliviating headache in patients with cevical myelopathy, and that what they have in common was that was the decompression of spinal cord, it can be assumed that the headache associated with cervical spondylosis may be the result of compression on the spinal cord.

CONCLUSIONS

Anterior cervical discectomy and fusion, total disk replacement and open door laminoplasty can all significantly alleviate headache in patients with cervical spondylotic myelopathy and/or radiculopathy. No surgical technique is better than any other technique on alleviating cervical headache associated with cervical spondylotic myelopathy and/or radiculopathy.

Marker-Free Tracking of Facet Capsule Motion Using Polarization-Sensitive Optical Coherence Tomography

We proposed and tested a method by which surface strains of biological tissues can be captured without the use of fiducial markers by instead, utilizing the inherent structure of the tissue. We used polarization-sensitive optical coherence tomography (PS OCT) to obtain volumetric data through the thickness and across a partial surface of the lumbar facet capsular ligament during three cases of static bending. Reflectivity and phase retardance were calculated from two polarization channels, and a power spectrum analysis was performed on each a-line to extract the dominant banding frequency (a measure of degree of fiber alignment) through the maximum value of the power spectrum (maximum power). Maximum powers of all a-lines for each case were used to create 2D visualizations, which were subsequently tracked via digital image correlation. In-plane strains were calculated from measured 2D deformations and converted to 3D surface strains by including out-of-plane motion obtained from the PS OCT image. In-plane strains correlated with 3D strains (R(2) ≥ 0.95). Using PS OCT for marker-free motion tracking of biological tissues is a promising new technique because it relies on the structural characteristics of the tissue to monitor displacement instead of external fiducial markers.

Cervical spondylosis and hypertension: a clinical study of 2 cases

Cervical spondylosis and hypertension are all common diseases, but the relationship between them has never been studied. Patients with cervical spondylosis are often accompanied with vertigo. Anterior cervical discectomy and fusion is an effective method of treatment for cervical spondylosis with cervical vertigo that is unresponsive to conservative therapy. We report 2 patients of cervical spondylosis with concomitant cervical vertigo and hypertension who were treated successfully with anterior cervical discectomy and fusion. Stimulation of sympathetic nerve fibers in pathologically degenerative disc could produce sympathetic excitation, and induce a sympathetic reflex to cause cervical vertigo and hypertension. In addition, chronic neck pain could contribute to hypertension development through sympathetic arousal and failure of normal homeostatic pain regulatory mechanisms. Cervical spondylosis may be one of the causes of secondary hypertension. Early treatment for resolution of symptoms of cervical spondylosis may have a beneficial impact on cardiovascular disease risk in patients with cervical spondylosis.

Morphological observation of sympathetic nerve fibers in the human posterior longitudinal ligament

STUDY DESIGN

Histological study of human living tissue.

OBJECTIVE

To determine sympathetic fiber in the cervical posterior longitudinal ligaments (PLL) obtained from the patients undergoing anterior cervical decompression surgery, and speculate the implication of their presence and distribution.

SUMMARY OF BACKGROUND DATA

The pathogenic mechanism responsible for cervical spondylosis remains unclear. Cervical vertigo is often confused with aural vertigo, and central vertigo, and et al. It has been gradually realized that mechanical interference to the vertebral artery is not the only way to explain the pathogenic mechanism of cervical vertigo. It should be noted that the sympathetic factor may also involve it because some sympathetic nerves were found in the PLL in an animal study of intervertebral discs. Although it is unclear whether there is a similar phenomenon in adult human PLL.

METHODS

Forty-six patients who received anterior cervical decompression surgery in The Affiliated Hospital of Qingdao University from January 2013 to December 2013 were classified into 2 groups: with cervical spondylosis and with cervical trauma. Cervical PLL tissues of all the participants were obtained during operation. The paraffin slices of the ligament were stained according to glyoxylic acid-induced fluorescent method. The morphology and distribution of sympathetic nerve fibers were observed by measuring and analyzing fluorescent units expressed on different sections. The positive rates expressed by fluorescent staining were statistically analyzed.

RESULTS

Different forms of sympathetic nerve fibers distribution were observed in the 3-dimensional slices in each group selected from 46 cases of specimens. The positive rate of fluorescent units detected from the cervical PLL in patients experiencing cervical spondylosis was not significantly different from that in cervical trauma group (x = 0.969, P > 0.05).

CONCLUSION

Sympathetic nerve fibers were confirmed to distribute in the human cervical posterior longitudinal ligament.

LEVEL OF EVIDENCE

2.

Sympathetic nerve innervation in cervical posterior longitudinal ligament as a potential causative factor in cervical spondylosis with sympathetic symptoms and preliminary evidence

Sympathetic symptoms associated with cervical disorders, such as vertigo, headache, dizziness, etc., are common clinical disorders bewildering both clinicians and patients. In our clinical practice we observed that sympathetic symptoms associated with cervical disorders were apparently relieved in some patients after undergoing routine anterior cervical decompression and fusion plus posterior longitudinal ligament (PLL) resection. This study was designed to investigate the sympathetic nerve innervations in the cervical PLL and its potential correlation with cervical sympathetic symptoms such as vertigo.

METHOD

In animal research, cervical PLLs of 9 adult rabbits were harvested and stained with sucrose-phosphate-glyoxylic acid (SPG), which is a specific fluorescence staining method for sympathetic postganglionic fibers. In human research, cervical PLL of 8 patients of cervical spondylosis with sympathetic symptoms were harvested during surgery and stained with SPG. All sections were observed under fluorescence microscope. Sympathetic symptoms were evaluated using the sympathetic symptom 20-point score preoperatively and at 1 week, 2-month, and 6-month postoperatively.

RESULTS

In rabbit specimens, a large number of sympathetic postganglionic fibers were distributed in the cervical PLL of every segment. The density of sympathetic fibers distributed in the intervertebral portion of PLL was more than that in the vertebral portion. Compared with deep layer section, the nerve fibers in the superficial PLL layer section were thicker and more densely populated. Existence of sympathetic postganglionic fibers was also confirmed in human specimens. Those nerve fibers were mostly short and isolated in areatus form, with non-interwoven branches. The mean sympathetic symptoms score decreased significantly from 6.6 ± 2.6 before surgery to 2.0 ± 1.9 at 6 months postoperatively after anterior cervical decompression and fusion with PLL removed.

CONCLUSION

According to the experimental result and clinical practice, we hypothesized that sympathetic nerve fibers distributed in PLL may represent a pathologic basis of stimulation induced by cervical vertebral degenerative changes and thus are susceptible to being a potential causative factor in cervical spondylosis with sympathetic symptoms.

Degenerative pathological irritations to cervical PLL may play a role in presenting sympathetic symptoms

The mechanism of cervical vertigo remains unknown. Stimulation of arterial vertebralis caused by osteophyte of the Luschka joint or segmental instability of the cervical spine was considered to be a potential factor contributing to it. Years of studies found that the ischemia of the vertebral artery is not directly correlated with the clinical symptoms of vertigo, and can not be used to explain cervical vertigo as a sole reason. As proven by clinical practical experience, the routine anterior cervical decompression and fusion (ACDF) procedure, in which the degenerative disc and posterior longitudinal ligament (PLL) were often removed, shows positive results for elimination of the sympathetic symptoms. In this article, we hypothesize that: (1) there are sympathetic nerve postganglionic fibers distributed in the PLL or discs; (2) pathological changes secondary to degeneration of the intervertebral disc may cause irritation of sympathetic nerve fibers in PLL or discs, leading to sympathetic symptoms via certain pathways; (3) removal of the PLL or stabilization of the segment which decreases the irritation to PLL will help to eliminate the sympathetic symptoms.

Reflex control of the spine and posture: a review of the literature from a chiropractic perspective

OBJECTIVE

This review details the anatomy and interactions of the postural and somatosensory reflexes. We attempt to identify the important role the nervous system plays in maintaining reflex control of the spine and posture. We also review, illustrate, and discuss how the human vertebral column develops, functions, and adapts to Earth's gravity in an upright position. We identify functional characteristics of the postural reflexes by reporting previous observations of subjects during periods of microgravity or weightlessness.

BACKGROUND

Historically, chiropractic has centered around the concept that the nervous system controls and regulates all other bodily systems; and that disruption to normal nervous system function can contribute to a wide variety of common ailments. Surprisingly, the chiropractic literature has paid relatively little attention to the importance of neurological regulation of static upright human posture. With so much information available on how posture may affect health and function, we felt it important to review the neuroanatomical structures and pathways responsible for maintaining the spine and posture. Maintenance of static upright posture is regulated by the nervous system through the various postural reflexes. Hence, from a chiropractic standpoint, it is clinically beneficial to understand how the individual postural reflexes work, as it may explain some of the clinical presentations seen in chiropractic practice.

METHOD

We performed a manual search for available relevant textbooks, and a computer search of the MEDLINE, MANTIS, and Index to Chiropractic Literature databases from 1970 to present, using the following key words and phrases: "posture," "ocular," "vestibular," "cervical facet joint," "afferent," "vestibulocollic," "cervicocollic," "postural reflexes," "spaceflight," "microgravity," "weightlessness," "gravity," "posture," and "postural." Studies were selected if they specifically tested any or all of the postural reflexes either in Earth's gravity or in microgravitational environments. Studies testing the function of each postural component, as well as those discussing postural reflex interactions, were also included in this review.

DISCUSSION

It is quite apparent from the indexed literature we searched that posture is largely maintained by reflexive, involuntary control. While reflexive components for postural control are found in skin and joint receptors, somatic graviceptors, and baroreceptors throughout the body, much of the reflexive postural control mechanisms are housed, or occur, within the head and neck region primarily. We suggest that the postural reflexes may function in a hierarchical fashion. This hierarchy may well be based on the gravity-dependent or gravity-independent nature of each postural reflex. Some or all of these postural reflexes may contribute to the development of a postural body scheme, a conceptual internal representation of the external environment under normal gravity. This model may be the framework through which the postural reflexes anticipate and adapt to new gravitational environments.

CONCLUSION

Visual and vestibular input, as well as joint and soft tissue mechanoreceptors, are major players in the regulation of static upright posture. Each of these input sources detects and responds to specific types of postural stimulus and perturbations, and each region has specific pathways by which it communicates with other postural reflexes, as well as higher central nervous system structures. This review of the postural reflex structures and mechanisms adds to the growing body of posture rehabilitation literature relating specifically to chiropractic treatment. Chiropractic interest in these reflexes may enhance the ability of chiropractic physicians to treat and correct global spine and posture disorders. With the knowledge and understanding of these postural reflexes, chiropractors can evaluate spinal configurations not only from a segmental perspective, but can also determine how spinal dysfunction may be the ultimate consequence of maintaining an upright posture in the presence of other postural deficits. These perspectives need to be explored in more detail.