Considerations for Prophylactic Surgery in Asymptomatic Severe Cervical Stenosis: Review Article

Background

Cervical spondylotic myelopathy (CSM) is a devastating pathology that can severely impair quality of life. The symptoms in CSM progress slowly and often do not manifest until they become severe and potentially irreversible. There is a consensus that surgical intervention is warranted in symptomatic patients. The recovery of the neurologic deficit after surgical decompression of the spinal cord varies, and halting the progression of the disease remains the principle aim of surgery.

Questions/Purposes

The aim of this review is to address the key question of whether or not to intervene in cases that have radiographic evidence of significant cervical stenosis yet are asymptomatic or exhibit minimal symptoms?

Methods

The PubMed databases for publications that addressed asymptomatic cervical spondylotic myelopathy were reviewed. The relevant articles were selected after screening all the resulting abstracts. The references of the relevant articles were then reviewed, and cross references with titles discussing CSM were picked up for review.

Results

The search identified 14 papers which were reviewed. Seven articles were found to be relevant to the subject in question. Going through the references of the relevant articles, three articles were found to be directly related to the topic in study.

Conclusion

There is paucity of evidence to support for or against surgery in the setting of asymptomatic cervical spondylotic myelopathy despite radiographic evidence of severe stenosis. Patient factors such as age, level of activity, and risk of injury should be considered in formulating a management plan. Moreover, the patient should play an integral role in the process of decision making.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9426-4) contains supplementary material, which is available to authorized users.     

Postmortem findings in a woman with history of laminoplasty for severe cervical spondylotic myelopathy

Context

We report the autopsy of a 65-year-old woman who underwent a C3–C7 laminoplasty 4 years after the diagnosis of cervical spondylotic myelopathy (CSM). Her sensory disturbance, spasticity, and vesicorectal disturbance, which corresponded to long tract sign, had improved after surgery.

Findings

Cross sections at the C4–C5 level showed a triangular shape because of atrophied ventral gray matter. Moreover, despite the scarce glial scar formation around the cystic cavity, regeneration of gray matter had not occurred. In the white matter, the posterior and lateral funiculi were shrunken including three to four segments.

Conclusion

Pathological change of white matter did not coincide with relief of clinical symptoms in this case. These findings indicate that it may be better to operate earlier in cases of CSM, because delay may lead to irreversible histological change.     

Biomechanical analysis of cervical spondylotic myelopathy: the influence of dynamic factors and morphometry of the spinal cord

Objective

Patients with cervical spondylotic myelopathy (CSM) have the same clinical symptoms that vary according to the degree of spinal cord compression and the cross-sectional cord shape. We used a three-dimensional finite element method (3D-FEM) to analyze the stress distributions of the spinal cord with neck extension under three cross-sectional cord shapes.

Methods

Experimental condition for the 3D-FEM spinal cord, ligamentum flavum, and anterior compression shape (central, lateral, and diffuse types) was established. To simulate neck extension, the spinal cord was extended by 20° and the ligamentum flavum was shifted distally according to movement of the cephalad lamina.

Results

The stress distribution in the spinal cord increased due to invagination of the ligamentum flavum into the neck extension. The range of stress distribution observed for the diffuse type was wider than for the central and lateral types. In addition, the stress distribution in the spinal cord was increased by the pincer movement of the ligamentum flavum and by the anterior compression of the spinal cord. The range of stress distribution observed for the diffuse type under antero-posterior compression was also wider than for the central and lateral types.

Conclusion

This simulation model showed that the clinical symptoms of CSM due to compression of the diffuse type may be stronger than for the central and lateral types. Therefore, careful follow-up is recommended for anterior compression of the spinal cord of diffuse type.     

Functional outcome of corpectomy in cervical spondylotic myelopathy

Background:

Cervical spondylotic myelopathy (CSM) is serious consequence of cervical intervertebral disk degeneration. Morbidity ranges from chronic neck pain, radicular pain, headache, myelopathy leading to weakness, and impaired fine motor coordination to quadriparesis and/or sphincter dysfunction. Surgical treatment remains the mainstay of treatment once myelopathy develops. Compared to more conventional surgical techniques for spinal cord decompression, such as anterior cervical discectomy and fusion, laminectomy, and laminoplasty, patients treated with corpectomy have better neurological recovery, less axial neck pain, and lower incidences of postoperative loss of sagittal plane alignment. The objective of this study was to analyze the outcome of corpectomy in cervical spondylotic myelopathy, to assess their improvement of symptoms, and to highlight complications of the procedure.

Materials and Methods:

Twenty-four patients underwent cervical corpectomy for cervical spondylotic myelopathy during June 1999 to July 2005.The anterior approach was used. Each patient was graded according to the Nuricks Grade (1972) and the modified Japanese Orthopaedic Association (mJOA) Scale (1991), and the recovery rate was calculated.

Results:

Preoperative patients had a mean Nurick''s grade of 3.83, which was 1.67 postoperatively. Preoperative patients had a mean mJOA score of 9.67, whereas postoperatively it was 14.50. The mean recovery rate of patients postoperatively was 62.35% at a mean follow-up of 1 year (range, 8 months to 5 years).The complications included one case (4.17%) of radiculopathy, two cases (8.33%) of graft displacement, and two cases (8.33%) of screw back out/failure.

Conclusions:

Cervical corpectomy is a reliable and rewarding procedure for CSM, with functional improvement in most patients.     

Die zervikale spondylotische Myelopathie

Background

The pathogenesis of cervical spondylotic myelopathy (CSM) is often multifactorial. Hence, the treatment of this disease requires a differentiated surgical approach in order to adequately address the underlying pathology.

Purpose

The aim of this review is to identify factors that influence the choice of treatment strategy and to summarize them in an algorithm that serves as a decision aid in choosing the optimal indication for surgical treatment. An attempt is made to define the threshold values for the indication of surgical treatment and to discuss the ideal timing for performing surgery.

Materials and methods

On the basis of the published data, the influencing factors on the prognosis of CSM, as well as surgical approaches are discussed.

Results

Circumferential spinal cord compression, a sharply defined myelopathy signal in the T2-weighted MRI sequence, and segmental instability at the level of the myelopathy signal mean an unfavorable prognosis for the worsening of CSM. The most important factors that influence the choice of the surgical access point are the sagittal profile of the cervical spine, the extent of myelopathy, the extent of stenosis, and the location of the myelopathy-inducing pathology. Previously existing neck pain and prior cervical surgery must also be considered.

Discussion

On the basis of the research carried out, we developed an algorithm that could serve as an aid in choosing the right treatment in the setting of cervical spondylotic myelopathy.

     

Complex cervical spondylotic myelopathy: a report of two cases and literature review

Study Design

A report of two cases with complex cervical spondylotic myelopathy (CSM) and review of the literature.

Objective

To describe two unique patients with complex CSM due to simultaneous anomalies as anteroposterior compressions of the spinal cord in both upper and lower cervical spine, caused by hypertrophic transverse ligament of atlas (TLA), dysplasia of the posterior arch of atlas, disc herniation, hypertrophic ligamentum flavum and osteophytes.

Methods

We present such two cases with clinical, imageological presentations, and describe the surgical procedure, to which both patients responded favorably.

Results

The neurological functions of both patients gradually improved according to the JOA scores and VAS scores in preoperative clumsiness and gait disturbance during the mean follow-up period lasted for 18 months. The latest plain radiographs and computed tomography (CT) revealed good fusion without instrumental failure and magnetic resonance imaging (MRI) showed good decompression of C1–7 spinal cord of both patients. Both patients are progressively followed-up.

Conclusion

Posterior surgical approach as C1–7 laminectomy with fixations or occipital-cervical fusions may obtain better reconstructions of the cervical spine and good neurological recovery for the patients with complex CSM we present. However, the incidence and ethnic predisposition for the patients with complex CSM are still unclear.

     

Cervical spondylotic myelopathy: the relevance of the spinal cord back shift after posterior multilevel decompression. A systematic review

Purpose

Spinal cord back shift has been considered the desired end point of posterior decompression procedures for cervical spondylotic myelopathy (CSM). However, the association with postoperative outcomes has not been definitively demonstrated. The aim of this review is to obtain an overview of the current knowledge on the spinal back shift after posterior decompression to clarify the main controversial aspects and provide recommendations for further studies on the subject.

Methods

A comprehensive quantitative review of the literature was performed. Bibliographic databases were searched using the following keywords: spinal cord drift, spinal cord shift, CSM, ossification of posterior longitudinal ligament, posterior decompression, laminoplasty, laminectomy and fusion.

Results

Twelve eligible studies were included. The authors measured the spinal cord back shift in different ways, using the posterior edge, the center or the anterior margin of the spinal cord as reference points. Six studies analyzed the correlation between the spinal cord back shift and the recovery rate, but their results were discordant. The correlation between the posterior cord migration and cervical alignment was not confirmed in all studies.

Conclusions

There is a need for a consensus on the best way to measure the spinal cord back shift. The action of multiple factors on spinal cord back shift can explain the difference in the results collected from the studies. We recommend further studies to clarify the behavior of the spinal cord after posterior decompression and its clinical meaning.

     

Cervical cord compressive myelopathy in a man with a primary complaint of knee pain

Background:

Diagnosing patients with cervical cord compressive myelopathy in a timely manner can be challenging due to varying clinical presentations, the absence of pathognomonic findings, and symptoms that are usually insidious in nature.

Objective:

To describe the clinical course of a patient with primary complaint of left medial knee pain that was nonresponsive to surgical and conservative measures; the patient was subsequently diagnosed with cervical cord compressive myelopathy.

Design:

Case report.

Subject:

A 63-year-old man with a primary complaint of left medial knee pain.

Findings:

Physical examination of the left knee was normal except for slight palpable tenderness over the medial joint line. During treatment, he noted loss of balance during activities of daily living. Reassessment revealed bilateral upper extremity hyperreflexia, bilateral Babinski reflex, and positive bilateral Hoffman reflex. Magnetic resonance imaging of the cervical spine demonstrated moderately severe spinal stenosis at the C3-C4, C5-C6, and C6-C7 levels. After C3-C7 laminoplasty for cervical cord compressive myelopathy, he reported substantial improvement of his left medial knee. Three years later, he had no complaint of knee pain.

Conclusion:

Appropriate diagnosis and treatment of cervical cord compressive myelopathy may avoid unnecessary diagnostic imaging, medical evaluations, invasive procedures, and potential neurologic complications.     

Gait impairment in cervical spondylotic myelopathy: comparison with age- and gender-matched healthy controls

Introduction

Gait impairment is a primary symptom of cervical spondylotic myelopathy (CSM); however, little is known about specific kinetic and kinematic gait parameters. The objectives of the study were: (1) to compare gait patterns of people with untreated CSM to those of age- and gender-matched healthy controls; (2) to examine the effect of gait speed on kinematic and kinetic parameters.

Materials and methods

Sixteen patients with CSM were recruited consecutively from a neurosurgery clinic, and 16 healthy controls, matched to age (±5 years) and gender, were recruited for comparison. Patients and controls underwent three-dimensional gait analysis using a Vicon^® motion analysis system, at self-selected speed over a 10-m track. Controls were also assessed at the speed of their CSM match.

Results

At self-selected speed, the CSM group walked significantly more slowly, with shorter stride lengths and longer double support duration. They showed significant decreases in several kinematic and kinetic parameters, including sagittal range of motion at the hip and knee, ankle plantarflexion, anteroposterior ground reaction force (GRF) at toe-off, power absorption at the knee in loading response and terminal stance, and power generation at the ankle. At matched speed, the CSM group showed significant decreases in knee flexion during swing, total sagittal knee range of motion, peak ankle plantarflexion and anteroposterior GRF.

Conclusion and implications

The findings suggested that people with CSM have significant gait abnormalities that have not been previously reported. In particular, there are key differences in the motor strategies used in the terminal stance phase of gait that cannot be explained by speed alone.     

Copper deficiency myelopathy: A report of two cases

Context

Copper deficiency myelopathy represents an often underdiagnosed, acquired neurological syndrome, clinically characterized by posterior column dysfunction. The main causes of copper deficiency are bariatric surgery, increased consumption of zinc, and malabsorption. However, even after a careful history taking and extensive laboratory researches, the etiology of copper deficiency remains undetermined in a significant percentage of cases. Patients affected by copper deficiency myelopathy usually present with sensory ataxia due to dorsal column dysfunction and sometimes with mild leg spasticity. In such patients, spinal cord magnetic resonance imaging (MRI) may show hyperintense lesions in T2-weighted sequences involving the posterior columns of cervical and thoracic cord. These MRI findings are not distinguishable from those of subacute combined degeneration associated with vitamin B12 deficiency.

Findings

Here, we describe two patients with gait ataxia and sensory symptoms in which a diagnosis of copper deficiency myelopathy was made. Both patients showed a significant clinical, neuroradiological, and neurophysiological improvement after proper supplementation therapy.

Conclusion

The patients herein described underline the importance to include serum copper and ceruloplasmin levels as part of the myelopathy diagnostic workup, especially in the cases of otherwise unexplained subacute myelopathy involving the posterior columns. Since copper deficiency myelopathy is a progressive syndrome, early diagnosis is mandatory in order to promptly provide a proper supplementation therapy and, thus, prevent an irreversible neurological damage.     

Thoracic Myelopathy Secondary to Intradural Extramedullary Bronchogenic Cyst

Background/Objective:

To report a case of thoracic myelopathy secondary to intradural extramedullary bronchogenic cyst.

Study Design:

Case report.

Methods/Findings:

A 20-year-old man presented to the emergency department with increasing back pain and lower-extremity weakness. Magnetic resonance imaging demonstrated a cystic lesion at the T4 level with mass effect on the spinal cord.

Results:

The lesion was resected, and histopathologic evaluation showed a cyst lined by respiratory-type epithelium consistent with a bronchogenic cyst.

Conclusions:

Intradural extramedullary bronchogenic cysts of the thoracic spine have been reported previously but are extremely rare. The treatment of choice is surgical resection.     

Efficacy of multilevel anterior cervical discectomy and fusion versus corpectomy and fusion for multilevel cervical spondylotic myelopathy: a minimum 5-year follow-up study

Purpose

We evaluated radiologic and clinical outcomes to compare the efficacy of anterior cervical discectomy and fusion (ACDF) and anterior corpectomy and fusion (ACCF) for multilevel cervical spondylotic myelopathy (CSM).

Methods

A total of 40 patients who underwent ACDF or ACCF for multilevel CSM were divided into two groups. Group A (n = 25) underwent ACDF and group B (n = 15) ACCF. Clinical outcomes (JOA and VAS scores), perioperative parameters (length of hospital stay, blood loss, operation time), radiological parameters (fusion rate, segmental height, cervical lordosis), and complications were compared.

Results

Both group A and group B demonstrated significant increases in JOA scores and significant decreases in VAS. Patients who underwent ACDF experienced significantly shorter hospital stays (p = 0.031), less blood loss (p = 0.001), and shorter operation times (p = 0.024). Both groups showed significant increases in postoperative cervical lordosis and achieved satisfactory fusion rates (88.0 and 93.3 %, respectively). There were no significant differences in the incidence of complications among the groups.

Conclusions

Both ACDF and ACCF provide satisfactory clinical outcomes and fusion rates for multilevel CSM. However, multilevel ACDF is associated with better radiologic parameters, shorter hospital stays, less blood loss, and shorter operative times.     

Modern Instrumentation of the Pediatric Occiput and Upper Cervical Spine: Review Article

Background

Rigid screw rod techniques for cervical stabilization are widely used in adults. The benefits of rigid internal fixation include increased fusion rates, improvements in deformity correction, and diminished immobilization requirements. Applications of these techniques in children are challenging due to size constraints and the pathologic conditions encountered which require instrumented cervical fusions. Preparation as well as thorough understanding of the anatomy and surgical techniques is paramount to surgical safety in pediatric patients.

Questions/Purposes

This review article serves as an educational tool regarding the use of modern posterior instrumentation techniques for pediatric cervical deformity.

Methods

Expert review based on clinical expertise and literature review.

Results

The use of rigid screw rod instrumentation for the pediatric occiput and upper cervical spine is discussed. Preoperative imaging requirements for pediatric patients undergoing cervical spine surgery are reviewed. Anatomy, morphologic studies, and surgical techniques are discussed for each area of instrumentation.

Conclusions

Modern posterior cervical instrumentation techniques can be safely applied to the majority of pediatric patients who require an instrumented posterior cervical fusion. Patient safety revolves around thorough preoperative imaging tests, understanding of upper cervical anatomy, and meticulous surgical technique. Modern instrumentation leads to an improvement in fusion rates and a diminishment in immobilization requirements.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9398-4) contains supplementary material, which is available to authorized users.     

Full-endoscopic cervical arcocristectomy for the treatment of spinal stenosis: results of a cadaver study

Purpose

Cervical spondylotic myelopathy is a multifactorial disease that is directly correlated by the degree of spinal stenosis. Surgery remains the best therapy. A posterior approach is often recommended in patients with multilevel dorsal cervical compression. Aim of the present experimental study was to evaluate the feasibility of a full-endoscopic arcocristectomy in a cadaver study.

Methods

We performed full-endoscopic arcocristectomy on ten formalin-fixed human cervical specimens. Before and after decompression we obtained high-resolution computerized tomography (CT) data to evaluate the diameter of the cervical spinal canal.

Results

Overall, surgery was possible on 55 segments in ten cadaver specimens. A mean increase of 4.1 mm (±1.2 mm) in the sagittal diameter of the cervical spinal canal could be achieved (p < 0.05, t test).

Conclusions

The full-endoscopic arcrocristectomy is feasible and achieves a sufficient decompression. This minimal invasive technique protects most of the dorsal structures and therefore probably preserves biomechanical functions, which has to be proven in future studies.     

Biomechanical study of the spinal cord in thoracic ossification of the posterior longitudinal ligament

Background

Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy. This is often progressive and is not affected by conservative treatment. Therefore, decompressive surgery is usually chosen.

Objective

To conduct a stress analysis of the thoracic OPLL.

Methods

The three-dimensional finite element spinal cord model was established. We used local ossification angle (LOA) for the degree of compression of spinal cord. LOA was the medial angle at the intersection between a line from the superior posterior margin at the cranial vertebral body of maximum OPLL to the top of OPLL with beak type, and a line from the lower posterior margin at the caudal vertebral body of the maximum OPLL to the top of OPLL with beak type. LOA 20°, LOA 25°, and LOA 30° compression was applied to the spinal cord in a preoperative model, the posterior decompressive model, and a model for the development of kyphosis.

Results

In a preoperative model, at more than LOA 20° compression, high stress distributions in the spinal cord were observed. In a posterior decompressive model, the stresses were lower than in the preoperative model. In the model for development of kyphosis, high-stress distributions were observed in the spinal cord at more than LOA 20° compression.

Conclusions

Posterior decompression was an effective operative method. However, when the preoperative LOA is more than 20°, it is very likely that symptoms will worsen. If operation is performed at greater than LOA 20°, then correction of kyphosis by fixation of instruments or by forward decompression should be considered.     

Solitary sclerosis: Progressive neurological deficit from a spatially isolated demyelinating lesion: A further report

Context

Progressive myelopathy can be a manifestation of a variety of disorders including progressive multiple sclerosis. However it is extremely uncommon for a single lesion to cause a progressive myelopathy in MS. Such a myelopathy, i.e. a progressive neurological deficit from a solitary demyelinating lesion, not fulfilling the International diagnostic criteria for MS or Neuromyelitis Optica was first reported in 2012 and termed ‘solitary sclerosis’.

Method

We report 3 further cases of progressive myelopathy fulfilling the diagnostic criteria for solitary sclerosis.

Findings

Two patients had a single demyelinating lesion in the cervical cord and the third patient had it in the brain stem. All patients had serial MRI scans showing no dissemination or progression of lesions. Extensive diagnostic tests including aquaporin 4 antibodies were negative in all. At last follow-up at a median of 3.8 years, all patients continued to clinically progress despite immunosuppressive treatment.

Conclusion/Clinical Relevance

Solitary demyelinating lesions can cause a progressive myelopathy without clinical or radiological evidence of dissemination. Importantly, clinicians, both surgical and medical should be aware of such a diagnosis, to avoid invasive and often harmful tests particularly biopsies.     

Dorsal column myelopathy following intrathecal chemotherapy for acute lymphoblastic leukemia

Objective/context

To describe a distinctive clinical and radiographic pattern of myelopathy following intrathecal chemotherapy. Myelopathy is a rare complication of intrathecal chemotherapy used in the treatment of acute lymphoblastic leukemia (ALL). We present a 42-year-old female with T-cell ALL who developed a myelopathy primarily involving the dorsal columns.

Method

Case report and literature review.

Findings

Within 24 hours of an injection of intrathecal methotrexate, cytarabine, and hydrocortisone, the patient developed ascending lower limb numbness and balance difficulties progressing to the inability to ambulate. Clinical examination showed profound loss of lower limb proprioception and light touch sensation below T5, mild proximal limb weakness, but preserved pinprick and temperature sensation with intact bowel and bladder function. Initial thoracic and lumbar spine magnetic resonance imaging (MRI) at 1 week revealed no abnormalities. However, repeat imaging at 6 weeks showed abnormal signal in the posterior cord with sparing of the anterior and lateral columns, diffusely involving the lower cervical cord through the conus medullaris. Dermatomal somatosensory-evoked potential (DSEP) conduction abnormalities were consistent with thoracic myelopathy. An empiric trial of high-dose intravenous corticosteroids during inpatient rehabilitation more than 6 weeks later produced no significant clinical improvement.

Conclusion/clinical relevance

Preferential and persistent dorsal column myelopathy is a distinctive clinical and radiographic presentation of a rare complication of intrathecal chemotherapy. The MRI abnormalities were initially absent, but evolved to consist of multi-level spinal cord T2 and STIR hyperintensity with regional gadolinium enhancement. DSEPs more accurately reflected the clinical level of spinal cord dysfunction.