Predictive factors for spondylotic cervical myelopathy treated conservatively or surgically

Degenerative Cervical Myelopathy: A Concept Review and Clinical Approach

STUDY DESIGN

Narrative review.

OBJECTIVE

To provide an overview of the evaluation and diagnosis of degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

DCM describes several etiologies of degenerative, nontraumatic spinal cord impairment. Early diagnosis and intervention can decrease neurological decline.

METHODS

An extensive literature review was conducted.

RESULTS

The incidence and prevalence of DCM are increasing worldwide. Asymptomatic spinal cord compression can progress to cervical myelopathy. Static and dynamic factors contribute to spinal cord compression. Patients frequently present with decreased manual dexterity, gait instability, and neck pain. On physical exam, patients frequently present with upper motor neuron signs, a Lhermitte sign, a failed Romberg test, global proprioceptive dysfunction, and decreased pain sensation. Anatomic variation may complicate physical exam interpretation. The modified Japanese Orthopaedic Association Scale and Nurick Classification, based on functional impairment, provide diagnostic utility. Magnetic Resonance Imaging imaging is useful in narrowing the differential diagnosis, evaluating the severity of neurological impairment, and predicting disease progression.

CONCLUSIONS

Understanding the pathophysiology of DCM and the diagnostic utility of the signs and symptoms of DCM is critical. The decision for anterior cervical discectomy and fusion (ACDF), laminoplasty, or combined ACDF and posterior cervical fusion is individualized for each patient.

Natural history of degenerative cervical myelopathy: a meta-analysis and neurologic deterioration survival curve synthesis

BACKGROUND CONTEXT

Cervical spine surgery is rapidly increasing, and our knowledge of the natural history of degenerative cervical myelopathy (DCM) is limited.

PURPOSE

To synthesize accurate time-based estimates of meaningful neurologic decline in patients with DCM managed conservatively and to provide formulae to help communicate survivorship estimates to patients.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review and meta-analysis was conducted using Cochrane and PRISMA guidelines. A librarian-assisted search strategy using multiple databases with broad search terms and validated filter functions was used. All articles were reviewed in duplicate.

RESULTS

A total of 9570 studies were captured in the initial search, which after deletion of duplicates and manual review of abstracts and full texts revealed 6 studies for analyses. All studies were prospective cohorts or randomized controlled trials. The pooled survival estimates for neurologic stability (95% CrI) for mild DCM patients are: 91% (83%-97%) at one year; 85% (72%-94%) at 2 years; 84% (70%-94%) at 3 years; 75% (54%-90%) at 5 years; 66% (40%-86%) at 15 years; and 65% (39%-86%) at 20 years. The pooled survival estimates for neurologic stability (95% CrI) for moderate/severe DCM patients are: 83% (76%-89%) at 1 year; 72% (62%-81%) at 2 years; 71% (60%-80%) at 3 years; 55% (41%-68%) at 5 years; 44% (27%-59%) at 15 years; and 43% (25%-58%) at 20 years.

CONCLUSIONS

This is the first quantitative synthesis of the totality of published data on DCM natural history. Our review confirms a slow decline in neurologic function. We developed formulae which can be easily used by surgeons to communicate to patients their risk of neurologic deterioration. These formulae can be used to facilitate the shared decision-making process.

Anterior cervical corpectomy for the treatment of spondylotic myelopathy: results of a prospective double-armed study with a three-year follow-up

BACKGROUND

Since the first description in the 1950s, cervical spondylotic myelopathy (CSM) has posed many challenges to neurosurgeons and spine surgeons. Direct comparison among different operative approaches has failed to produce valuable results due to either an insufficient number of enrolled patients or a lack of standardization of baseline conditions. This prospective double-armed non-randomized study with a 3-year follow-up involved 80 patients with degenerative cervical myelopathy surgically and conservatively treated. The primary aim was to determine the efficacy of corpectomy in mild-moderate and severe CSM and to compare the outcomes of conservative and surgical treatment.

METHODS

Eighty patients were stratified into two arms, on the basis of the mJOA score: mild-moderate (mJOA ≥12) and severe myelopathy (mJOA score <12). Each arm was subdivided into two treatment groups (operative or conservative): A1, mild-moderate myelopathy treated with corpectomy; A2, mild-moderate myelopathy treated conservatively; B1, severe myelopathy treated with corpectomy; B2, severe cervical myelopathy treated conservatively. The clinical outcome was evaluated with the modified JOA score, timed 10-meter walk, Mehalic grade, motor evoked potentials, the SF-12, and further assessed by external observers blinded to the type of treatment.

RESULTS

No significant differences in the recovery rates were found between the A1 and A2 groups at 6 months, although better results were recorded in the surgical groups (A1 and B1) at 12 months and at the final follow-up, as suggested by the significantly higher recovery rates. Multivariate analysis showed an inverse correlation between the duration of symptoms and the recovery rate (P<0.0001). Moreover, the preoperative timed 10-meter walk (P<0.004), the preoperative hypointensity on T1-weighted MR images (P<0.001), a higher Mehalic grade (P<0.02), the pre-treatment MEP (P<0.002), and the preoperative spinal canal diameter (P<0.004) significantly influenced the recovery rate.

CONCLUSIONS

This prospective double-armed non-randomized study demonstrates that corpectomy is an effective and safe treatment, especially for severe forms of myelopathy. In mild-moderate conditions, a discrepancy between neurological improvement and expressed level of satisfaction was found. The present results also show that a multiparametric evaluation is crucial for proper patient selection for corpectomy.

Long-Term Survivorship of Cervical Spine Procedures; A Survivorship Meta-Analysis and Meta-Regression

STUDY DESIGN

Systematic Review.

OBJECTIVES

To conduct a meta-analysis on the survivorship of commonly performed cervical spine procedures to develop survival function curves for (i) second surgery at any cervical level, and (ii) adjacent level surgery.

METHODS

A systematic review of was conducted following PRISMA guidelines. Articles with cohorts of greater than 20 patients followed for a minimum of 36 months and with available survival data were included. Procedures included were anterior cervical discectomy and fusion (ACDF), cervical disc arthroplasty (ADR), laminoplasty (LAMP), and posterior laminectomy and fusion (PDIF). Reconstructed individual patient data were pooled across studies using parametric Bayesian survival meta-regression.

RESULTS

Of 1829 initial titles, 16 citations were included for analysis. 73 811 patients were included in the second surgery analysis and 2858 patients in the adjacent level surgery analysis. We fit a Log normal accelerated failure time model to the second surgery data and a Gompertz proportional hazards model to the adjacent level surgery data. Relative to ACDF, the risk of second surgery was higher with ADR and PDIF with acceleration factors 1.73 (95% CrI: 1.04, 2.80) and 1.35 (95% CrI: 1.25, 1.46) respectively. Relative to ACDF, the risk of second surgery was lower with LAMP with deceleration factor .06 (95% CrI: .05, .07). ADR decreased the risk of adjacent level surgery with hazard ratio .43 (95% CrI: .33, .55).

CONCLUSIONS

In cases of clinical equipoise between fusion procedures, our analysis suggests superior survivorship with anterior procedures. For all procedures, laminoplasty demonstrated superior survivorship.

Degenerative Cervical Myelopathy: Development and Natural History [AO Spine RECODE-DCM Research Priority Number 2]

STUDY DESIGN

Narrative review.

OBJECTIVES

To discuss the current understanding of the natural history of degenerative cervical myelopathy (DCM).

METHODS

Literature review summarizing current evidence pertaining to the natural history and risk factors of DCM.

RESULTS

DCM is a common condition in which progressive arthritic disease of the cervical spine leads to spinal cord compression resulting in a constellation of neurological symptoms, in particular upper extremity dysfunction and gait impairment. Anatomical factors including cord-canal mismatch, congenitally fused vertebrae and genetic factors may increase individuals' risk for DCM development. Non-myelopathic spinal cord compression (NMSCC) is a common phenomenon with a prevalence of 24.2% in the healthy population, and 35.3% among individuals >60 years of age. Clinical radiculopathy and/or electrophysiological signs of cervical cord dysfunction appear to be risk factors for myelopathy development. Radiological progression of incidental Ossification of the Posterior Longitudinal Ligament (OPLL) is estimated at 18.3% over 81-months and development of myelopathy ranges between 0-61.5% (follow-up ranging from 40 to 124 months between studies) among studies. In patients with symptomatic DCM undergoing non-operative treatment, 20-62% will experience neurological deterioration within 3-6 years.

CONCLUSION

Current estimates surrounding the natural history of DCM, particularly those individuals with mild or minimal impairment, lack precision. Clear predictors of clinical deterioration for those treated with non-operative care are yet to be identified. Future studies are needed on this topic to help improve treatment counseling and clinical prognostication.

Prognostic Indices of Surgical Outcome in Cervical Spondylotic Myelopathy: A Clinical Prospective Study

BACKGROUND: One of the most common causes of spinal cord dysfunction is cervical spondylotic myelopathy (CSM) especially in the elderly. Prognostic indices can aid the surgeon preoperatively to detect the patients’ prognosis. AIM: The aim of the work is to better assess patients and to find possible indicators for post-operative improvement or deterioration in CSM patients. METHODS: Forty patients with multiple levels CSM, admitted and operated on in the Neurosurgery Department of Cairo University Hospitals, have been enrolled randomly in this study after fulfilling the criteria for CSM surgical intervention. The patient age, complaint duration, number of levels affected, signal intensity on T1-weighted and T2-weighted magnetic resonance (MR) images, Japan Orthopedic Association (JOA) scoring system, and Nurick’s score were evaluated before surgery and correlated with outcome after 1 year follow-up. RESULTS: About 80% of patients improved after operation with average pre- and post-operative JOA and Nurick scores about 11.23 and 3.12; 14.1 and 1.6, respectively. Patient age, sex, number of levels affected, and signal intensity on T1- weighted and T2-weighted MR images were not significantly associated with post-operative improvement, p > 0.05. However, the only significant prognostic factor was the duration of symptoms if less than 1 year with p < 0.05. CONCLUSION: Short complaint duration coupled with close intra-operative monitoring was directly correlated with good CMS operation outcome while age, sex, number of levels affected, presence of cord signal on MR imaging, and surgical approach appear to have no significant effect on outcome.

Cervical Spondylotic Myelopathy: When and Why the Cervical Corpectomy?

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a degenerative disease that represents the most common spinal cord disorder in adults. The best treatment option has remained controversial. We performed a prospective study to evaluate the clinical, radiographic, and neurophysiologic outcomes for anterior cervical corpectomy in the treatment of CSM.

METHODS

From January 2011 to January 2017, 60 patients with CSM were prospectively enrolled in the present study. The patients were divided according to the modified Japanese Orthopaedic Association scale (mJOA) score into 2 groups: group A, patients with mild to moderate CSM (mJOA score ≥13); and group B, patients with severe myelopathy (mJOA score <13). Data were collected for each participating subject, including demographic information, symptoms, medical history, radiologic and neurophysiologic features, and functional impairment.

RESULTS

Of the 60 patients, 35 were men (58.3%) and 25 were women (41.7%). Their average age was 57.48 ± 10.60 years. The mean symptom duration was 25.33 ± 16.00 months; range, 3-57 months). Of the 60 patients, 22 had undergone single-level corpectomy and 36 multilevel corpectomy. A significant improvement in the motor evoked potentials was observed in both groups.

CONCLUSIONS

Single- and multilevel corpectomy are valid and safe options in the treatment of CSM. In the present prospective study, a statistically significant improvement in the mJOA score and neurophysiologic parameters was observed for both moderate and severe forms of CSM.

Progression Prediction of Mild Cervical Spondylotic Myelopathy by Somatosensory-evoked Potentials

STUDY DESIGN

Retrospective study to correlate classification of somatosensory-evoked potentials (SEPs) with symptomatic progress of patients with mild cervical spondylotic myelopathy (CSM).

OBJECTIVE

The aim of this study was to evaluate the usefulness of SEPs for predicting symptomatic progress of mild CSM.

SUMMARY OF BACKGROUND DATA

SEPs have been used for clinical diagnosis and intraoperative neuromonitoring in patients with CSM. However, the prognostic value of SEPs in predicting the progression of CSM remains unclear.

METHODS

A total of 200 patients with a clinical diagnosis of mild CSM were enrolled between September 2014 and February 2018. All patients received clinical assessment with the modified Japanese Orthopedic Association scale (mJOA), magnetic resonance imaging, and SEP tests in the first clinical visit and at 1-year follow-up. A classification of upper and lower limbs SEP was developed. At 1-year follow-up, patients with symptom decline >2 points in mJOA were considered progressive myelopathy cases. The relationship of progressive myelopathy and classifications of SEP was investigated.

RESULTS

Fifty-four of 200 cases presented with progressive myelopathy. The incidence of progressive myelopathy was 2.6%, 27.7%, 23.8%, 86.7%, and 100% in Class I, II, III, IV, and V of upper SEPs, respectively, and 18.8%, 39.4%, 42.3%, and 62.5% in Class I, II, III, and IV of lower SEPs, respectively. For the combination classification of upper and lower SEPs, the incidence of progressive myelopathy was 0%, 13.7%, 24.3%, 91.1%, and 100% in Class I, II, III, IV, and V, respectively. There was a significant correlation of the incidence of progressive myelopathy with SEP classification for the upper SEPs (r = 0.94, P < 0.01) and the combination SEPs (r = 0.95, P < 0.01).

CONCLUSION

The incidence of progressive degenerative myelopathy increased with the upper and combination SEP classifications. Thus, classification of SEPs could predict the clinical decline in mJOA in CSM, reflecting the probability of worsening of myelopathy.

LEVEL OF EVIDENCE

4.

Treatment of Mild Cervical Myelopathy: Factors Associated With Decision for Surgical Intervention

STUDY DESIGN

Prospective Cohort OBJECTIVE.: The aim of this study was to evaluate which demographic, clinical, or radiographic factors are associated with selection for surgical intervention in patients with mild cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Surgery has not been shown superior to best conservative management in mild CSM comparative studies; trials of conservative management represent an acceptable alternative to surgical decompression. It is unknown what patients benefit from surgery.

METHODS

This is a prospective study of patients with mild CSM, defined as modified Japanese Orthopaedic Association Score (mJOA) ≥15. Patients were recruited from seven sites contributing to the Canadian Spine Outcomes Research Network. Demographic, clinical, radiographic and health related quality of life data were collected on all patients at baseline. Multivariate logistic regression modeling was used to identify factors associated with surgical intervention.

RESULTS

There were 122 patients enrolled, 105 (86.0%) were treated surgically, and 17 (14.0%) were treated nonoperatively. Overall mean age was 54.8 years (SD 12.6) with 80 (65.5%) males. Bivariate analysis revealed no statistically significant differences between surgical and nonoperative groups with respect to age, sex, BMI, smoking status, number of comorbidities and duration of symptoms; mJOA scores were significantly higher in the nonoperative group (16.8 [SD 0.99] vs. 15.9 [SD 0.89], P < 0.001). There was a statistically significant difference in Neck Disability Index, SF12 Physical Component, SF12 Mental Component Score, EQ5D, and PHQ-9 scores between groups; those treated surgically had worse baseline questionnaire scores (P < 0.05). There was no difference in radiographic parameters between groups. Multivariable analysis revealed that lower quality of life scores on EQ5D were associated with selection for surgical management (P < 0.018).

CONCLUSION

Patients treated surgically for mild cervical myelopathy did not differ from those treated nonoperatively with respect to baseline demographic or radiographic parameters. Patients with worse EQ5D scores had higher odds of surgical intervention.

LEVEL OF EVIDENCE

3.

[Operative treatment of the degenerative cervical spine]

BACKGROUND

Degenerative alterations of the cervical spine often entail disc herniations and stenoses of the spinal canal and/or neural foramen. Mediolateral or lateral compression of nerve roots causes cervical radiculopathy, which is an indication for surgery in cases of significant motor deficits or refractory pain. Median canal encroachment may result in compression of the spinal cord and cervical myelopathy. Its natural history is typically characterized by episodic deterioration, so that surgical decompression is indicated in cases of clear myelopathic signs.

OBJECTIVE

The aim of the present article is to outline the operative options for patients with cervical radiculopathy and myelopathy. Furthermore, we describe the operative complications and the outcome in these patients.

MATERIAL AND METHODS

For this manuscript a systematic PubMed search was carried out, the papers were systematically analyzed for the best evidence and this was combined with the authors' experience.

RESULTS AND CONCLUSION

Depending on the cervical pathology, the most prevalent surgical options for radiculopathy include anterior cervical discectomy and fusion (ACDF), cervical arthroplasty or posterior cervical foraminotomy. Cervical myelopathy may be decompressed by ACDF, corpectomy or posterior approaches like laminectomy plus instrumented fusion or laminoplasty. The outcome depends on the cervical pathology and the type of operation. Overall, in long-term follow-up studies the results of all surgical techniques on the cervical spine are generally considered to be very good, although specific patient characteristics are more suited for a particular approach.

Trial-to-trial latency variability of somatosensory evoked potentials as a prognostic indicator for surgical management of cervical spondylotic myelopathy

Background

Early detection of neural conductivity changes at the compressed spinal cord is important for predicting the surgical outcomes of patients with cervical spondylotic myelopathy (CSM). The prognostic value of median nerve somatosensory evoked potential (SEP) has been proposed previously. The present prospective study evaluates the use of trial-to-trial variability in SEP as a valuable predictor of neurological recovery after surgery of CSM.

Methods

A total of 35 CSM patients who underwent surgery with up to 6-month follow-up were recruited in this study. SEP signals were recorded preoperatively. The single trial SEP was extracted by a newly developed second-order blind identification method. The postoperative recovery was assessed using the modified Japanese Orthopaedic Association. The correlation between the latency variability of trial-to-trial SEP and post-operative recovery ratio was analyzed. The prognostic value of trial-to-trial SEP for CSM was evaluated using a receiver operator characteristic curve which can accurately reflect the relationship between sensitivity and specificity of a diagnostic method and represent the accuracy of prognosis.

Results

The correlation coefficient of trial-to-trial latency variability and the 6-month recovery ratio was statistically significant (r = −0.82, P < 0.01). The trial-to-trial SEP had a higher prognostic accuracy (AUC = 0.928, P < 0.001) with an optimal prognostic value of 9.25 % compared with averaged SEP when the threshold of recovery ratio was 40 %, and was more sensitive (93.80 %) than the averaged SEP (43.80 %).

Conclusions

These findings indicate that the latency variability of trial-to-trial SEP reflect the recovery ratio of CSM patients after surgery. It is suggested that the latency variability of trial-to-trial SEP is useful for predicting the surgical outcomes for patients with CSM, which would be a potential indication of surgical treatment for CSM to help decision making of surgical planning for CSM patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12984-015-0042-4) contains supplementary material, which is available to authorized users.

Epidemiology, diagnosis, and treatment of neck pain

Neck pain is the fourth leading cause of disability, with an annual prevalence rate exceeding 30%. Most episodes of acute neck pain will resolve with or without treatment, but nearly 50% of individuals will continue to experience some degree of pain or frequent occurrences. History and physical examination can provide important clues as to whether the pain is neuropathic or mechanical and can also be used to identify "red flags" that may signify serious pathology, such as myelopathy, atlantoaxial subluxation, and metastases. Magnetic resonance imaging is characterized by a high prevalence of abnormal findings in asymptomatic individuals but should be considered for cases involving focal neurologic symptoms, pain refractory to conventional treatment, and when referring a patient for interventional treatment. Few clinical trials have evaluated treatments for neck pain. Exercise treatment appears to be beneficial in patients with neck pain. There is some evidence to support muscle relaxants in acute neck pain associated with muscle spasm, conflicting evidence for epidural corticosteroid injections for radiculopathy, and weak positive evidence for cervical facet joint radiofrequency denervation. In patients with radiculopathy or myelopathy, surgery appears to be more effective than nonsurgical therapy in the short term but not in the long term for most people.

Transcranial magnetic stimulation of the motor cortex correlates with objective clinical measures in patients with cervical spondylotic myelopathy

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

To assess the correlation between central motor conduction time (CMCT) and various subjective and objective clinical assessment measures in patients undergoing decompressive surgery for cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

CSM can cause a spectrum of neurological deficits among individuals. Subjective clinical assessments of disease severity may lack the sensitivity of objective tests. Transcranial magnetic stimulation provides objective electrophysiological data on the integrity of the corticospinal tracts, which may be useful for monitoring disease progression or neurological improvement after surgery.

METHODS

Patients undergoing surgical decompression for CSM underwent subjective and objective testing before surgery and at 1, 3, 6, and 12 months after surgery. Subjective measures included modified Japanese Orthopaedic Association score, Neck Disability Index, Nurick grade, and visual analogue scale score. Objective measures included CMCT as measured using transcranial magnetic stimulation, the 10-m walk test, the 9-hole peg task, and the grip and release test. Primary outcome was the correlation between CMCT and subjective or objective measures at preoperative and postoperative time points. Secondary outcome was the correlation between preoperative CMCT and performance in subjective or objective testing after surgical intervention.

RESULTS

Improvement in both subjective and objective measures was observed after surgery. CMCT correlated with other objective measures (10-m walk test, 9-hole peg task, and grip and release test) both at baseline and after decompressive surgery in these 17 patients with CSM. Patients with high baseline CMCTs were associated with poor performance on the 10-m walk test, 9-hole peg task, and grip and release test. Modified Japanese Orthopaedic Association score correlated with CMCT at baseline but not after surgical intervention. CMCT was not associated with other subjective measures, such as Neck Disability Index, Nurick grade, and visual analogue scale score, at preoperative or postoperative time points.

CONCLUSION

CMCT as measured by transcranial magnetic stimulation is a responsive objective assessment of CSM. It can be used to monitor disease severity and neurological function before and after surgical intervention. Prolonged baseline CMCT may be associated with worse surgical outcomes.

LEVEL OF EVIDENCE

2.

[Diagnosis and management of cervical spondylosis]

Cervical spondylosis, which can present as radiculopathy and myelopathy, is common in people over the age of 50. Since evidence of radiological spondylotic change is frequently found in many asymptomatic adults, it is necessary to assess whether neurological symptoms result from cervical spondylosis or other neurological disorders. In order to avoid misdiagnosis, it is important to compare the levels of the lesions shown on imaging with the clinical findings. Differential diagnosis between amyotrophic lateral sclerosis and cervical spondylotic myelopathy is an issue of major clinical importance. Though the course of disease development and the ultimate prognosis for patients with cervical spondylosis is highly variable and extremely difficult to predict, many patients experience a relatively benign form of the disease.

Pathophysiology and natural history of cervical spondylotic myelopathy

STUDY DESIGN

This study is a combination of narrative and systematic review.

OBJECTIVE

Clinicians who deal with cervical spondylotic myelopathy (CSM) should be up-to-date with the emerging knowledge related to the cascade of pathobiological secondary events that take place under chronic cervical spinal cord compression. Moreover, by performing a systematic review, we aim to (1) describe the natural history and (2) determine potential risk factors that affect the progression of CSM.

SUMMARY OF BACKGROUND DATA

The pathophysiology, natural history, as well as the factors associated with clinical deterioration have not been fully described in CSM.

METHODS

For the first part of the study, a literature review was performed. To answer key questions 1 and 2 of the second goal, a systematic search was conducted in PubMed and the Cochrane Collaboration Library for articles published between January 1, 1956, and November 7, 2012. We included all articles that described the progression and outcomes of CSM for which no surgical intervention was given.

RESULTS

By performing a narrative literature review, we found that the assumption that acute traumatic spinal cord injury and CSM share a similar series of cellular and molecular secondary injury events was made in the past. However, recent advances in basic research have shown that the chronic mechanical compression results in secondary injury mechanisms that have distinct characteristics regarding the nature and the temporal profile compared with those of spinal cord injury. For the purpose of the systematic review, 10 studies yielding 16 publications met inclusion criteria for key questions 2 and 3. Moderate-strength evidence related to the natural history of CSM suggests that 20% to 60% of patients will deteriorate neurologically over time without surgical intervention. Finally, there is low-strength evidence indicating that the area of circumferential compression is associated with deteriorating neurological symptoms.

CONCLUSION

CSM has unique pathobiological mechanisms that mainly remain unexplored. Although the natural history of CSM can be mixed, surgical intervention eliminates the chances of the neurological deterioration. EVIDENCE-BASED CLINICAL RECOMMENDATIONS:

RECOMMENDATION

Evidence concerning the natural history of CSM suggests that 20% to 60% of patients will deteriorate neurologically over time without surgical intervention. Therefore, we recommend that patients with mild CSM be counseled regarding the natural history of CSM and have the option of surgical decompression explained.

OVERALL STRENGTH OF EVIDENCE

Moderate.

STRENGTH OF RECOMMENDATION

Strong. SUMMARY STATEMENTS: Chronic compression of the spinal cord results in progressive neural cell loss related to secondary mechanisms including apoptosis, neuroinflammation, and vascular disruption.

Predictors of outcome in patients with degenerative cervical spondylotic myelopathy undergoing surgical treatment: results of a systematic review

PURPOSE

To conduct a systematic review of the literature to determine important clinical predictors of surgical outcome in patients with cervical spondylotic myelopathy (CSM).

METHODS

A literature search was performed using MEDLINE, MEDLINE in Process, EMBASE and Cochrane Database of Systematic Reviews. Selected articles were evaluated using a 14-point modified SIGN scale and classified as either poor (<7), good (7-9) or excellent (10-14) quality of evidence. For each study, the association between various clinical factors and surgical outcome, evaluated by the (modified) Japanese Orthopaedic Association scale (mJOA/JOA), Nurick score or other measures, was defined. The results from the EXCELLENT studies were compared to the combined results from the EXCELLENT and GOOD studies which were compared to the results from all the studies.

RESULTS

The initial search yielded 1,677 citations. Ninety-one of these articles, including three translated from Japanese, met the inclusion and exclusion criteria and were graded. Of these, 16 were excellent, 38 were good and 37 were poor quality. Based on the excellent studies alone, a longer duration of symptoms was associated with a poorer outcome evaluated on both the mJOA/JOA scale and Nurick score. A more severe baseline score was related with a worse outcome only on the mJOA/JOA scale. Based on the GOOD and EXCELLENT studies, duration of symptoms and baseline severity score were consistent predictors of mJOA/JOA, but not Nurick. Age was an insignificant predictor of outcome on any of the functional outcomes considered.

CONCLUSION

The most important predictors of outcome were preoperative severity and duration of symptoms. This review also identified many other valuable predictors including signs, symptoms, comorbidities and smoking status.

Natural course and prognostic factors in patients with mild cervical spondylotic myelopathy with increased signal intensity on T2-weighted magnetic resonance imaging

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

To investigate natural course and prognostic factors in patients with mild forms of cervical spondylotic myelopathy (CSM), focusing on intramedullary increased signal intensity (ISI) on T2-weighted magnetic resonance imaging.

SUMMARY OF BACKGROUND DATA

Long-term natural course of mild forms of CSM, especially with ISI on magnetic resonance imaging, remains uncertain.

METHODS

Patients with CSM who visited our institution between 1992 and 2004 and did not undergo surgery at first visit were retrospectively reviewed. The inclusion criteria were as follows: (1) motor function Japanese Orthopedic Association scores of 3 or more in both upper and lower extremities and (2) cervical spinal cord compression with ISI on T2-weighted magnetic resonance imaging. There were 45 patients, with a mean follow-up period of 78 months (range, 24-208). We investigated long-term natural history by setting the timing of conversion to surgery due to neurological deterioration as an end point. We further compared prognostic parameters between patients who converted to surgery and those who continued to be followed up nonsurgically.

RESULTS

Sixteen patients gradually deteriorated and underwent decompression surgery, whereas 27 patients did not. Apart from these, 2 patients with acute spinal cord injury after minor trauma underwent surgery. Kaplan-Meier survival analysis revealed that 82% or 56% of patients did not require surgery 5 or 10 years after the initial treatment, respectively. As for prognostic factors, Cox proportional hazard analysis revealed that total cervical range of motion (hazard ratio: 3.25), segmental kyphosis in the maximum compression segment (hazard ratio: 4.51), and local slip (hazard ratio: 4.67) were statistically significant.

CONCLUSION

Fifty-six percent of patients with clinically mild CSM with ISI had not deteriorated or undergone surgery at 10 years. Large range of motion, segmental kyphosis, and instability at the narrowest canal were considered to be adverse prognostic factors.

Cervical spondylotic myelopathy

BACKGROUND

Cervical spondylosis is part of the aging process and affects most people if they live long enough. Degenerative changes affecting the intervertebral disks, vertebrae, facet joints, and ligamentous structures encroach on the cervical spinal canal and damage the spinal cord, especially in patients with a congenitally small cervical canal. Cervical spondylotic myelopathy (CSM) is the most common cause of myelopathy in adults.

REVIEW SUMMARY

The anatomy, pathophysiology, clinical presentation, differential diagnosis, diagnostic investigation, natural history, and treatment options for CSM are summarized. Patients present with signs and symptoms of cervical spinal cord dysfunction with or without cervical nerve root injury. The condition may or may not be accompanied by pain in the neck and/or upper limb. The differential diagnosis is broad. Imaging, typically with magnetic resonance imaging, is the most useful diagnostic tool. Electrophysiologic testing can help exclude alternative diagnoses. The effectiveness of conservative treatments is unproven. Surgical decompression improves neurologic function in some patients and prevents worsening in others, but is associated with risk.

CONCLUSIONS

Neurologists should be familiar with this very common condition. Patients with mild signs and symptoms of CSM can be monitored. Surgical decompression from an anterior or posterior approach should be considered in patients with progressive and moderate to severe neurologic deficits.

Tratamento cirúrgico por via anterior na mielopatia cervical espondilótica com seguimento mínimo de dez anos

OBJETIVO: a mielopatia cervical espondilótica (MEC) é uma causa frequente de disfunção da medula espinhal na população adulta. O tratamento implica em descompressão cirúrgica precoce. O objetivo foi apresentar um estudo retrospectivo da descompressão anterior e artrodese para MEC com um seguimento mínimo de dez anos. MÉTODOS: pacientes operados entre Janeiro de 1990 e Dezembro de 1994 foram avaliados por sexo, idade, número de níveis operados, avaliação funcional pela escala de Nurick pré-operatória um ano após cirurgia e após a revisão final que ocorreu em 2004, evidência de consolidação e complicações. RESULTADOS: foram avaliados 91 pacientes, 69 do sexo masculino, 22 do sexo feminino, com uma média de idade de 56,6 anos (42-86) e um seguimento médio de 11,9 anos. Ocorreram cinco óbitos: três pacientes no pós-operatório imediato, um no primeiro ano e um durante o restante período. Em média, foram operados 2,7±1,0 níveis por paciente (1-4). O valor médio de Nurick pré-operatório foi de 3,8±0,9. Houve uma melhoria significativa do estado neurológico um ano após a cirurgia (2,2±1,1; p<0,001) e entre o pré-operatório e a avaliação final (2,3±1,2; p<0,001). A degradação entre o primeiro ano e a avaliação final foi estatisticamente significativa (p=0,004). Verificou-se uma forte correlação entre a idade e o número de níveis operados (r=0,391; p=0,01), idade e estado neurológico inicial (r=0,238; p=0,05), estado neurológico inicial e número de níveis operados (r=0,251; p=0,05) e sexo e número de níveis operados, sendo as mulheres operadas a mais níveis (r=0,208; p=0,05). Verificou-se também uma maior deterioração neurológica entre o primeiro ano e a avaliação final em doentes mais jovens em comparação com os idosos (r=0,25; p=0,05). Há uma forte correlação entre a recuperação obtida ao primeiro ano e a recuperação final (r=0,838; p=0,01). A taxa de consolidação foi de 100%. CONCLUSÃO: na MEC, a cirurgia proporciona uma melhoria neurológica significativa e, apesar de uma deterioração clínica entre o primeiro ano e a avaliação final, os benefícios da descompressão são evidentes pelo menos dez anos após a intervenção.

Surgery for cervical radiculopathy or myelopathy

BACKGROUND

Cervical spondylosis causes pain and disability by compressing the spinal cord or roots. Surgery to relieve the compression may reduce the pain and disability, but is associated with a small but definite risk. .

OBJECTIVES

To determine whether: 1) surgical treatment of cervical radiculopathy or myelopathy is associated with improved outcome, compared with conservative management and 2) timing of surgery (immediate or delayed pending persistence/progression of relevant symptoms and signs) has an impact on outcome.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, and EMBASE to 1998 for the original review. A revised search was run in CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE, EMBASE, and CINAHL (January 1998 to June 2008) to update the review.Authors of the identified randomised controlled trials were contacted for additional published or unpublished data.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials allocating patients with cervical radiculopathy or myelopathy to 1) "medical management" or "decompressive surgery (with or without fusion) plus medical management" 2) "early decompressive surgery" or "delayed decompressive surgery".

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, assessed risk of bias and extracted data.

MAIN RESULTS

Two trials (N = 149) were included. In both trials, allocation concealment was inadequate and arrangements for blinding of outcome assessment were unclear.One trial (81 patients with cervical radiculopathy) found that surgical decompression was superior to physiotherapy or cervical collar immobilization in the short-term for pain, weakness or sensory loss; at one year, there were no significant differences between groups.One trial (68 patients with mild functional deficit associated with cervical myelopathy) found no significant differences between surgery and conservative treatment in three years following treatment. A substantial proportion of cases were lost to follow-up.

AUTHORS' CONCLUSIONS

Both small trials had significant risks of bias and do not provide reliable evidence on the effects of surgery for cervical spondylotic radiculopathy or myelopathy. It is unclear whether the short-term risks of surgery are offset by long-term benefits. Further research is very likely to have an impact on the estimate of effect and our confidence in it.There is low quality evidence that surgery may provide pain relief faster than physiotherapy or hard collar immobilization in patients with cervical radiculopathy; but there is little or no difference in the long-term.There is very low quality evidence that patients with mild myelopathy feel subjectively better shortly after surgery, but there is little or no difference in the long-term.

Degenerative cervical spinal stenosis: current strategies in diagnosis and treatment

INTRODUCTION

Cervical spinal stenosis has become more common because of the aging of the population. There remains much uncertainty about the options for surgical treatment and their indications, particularly in cases of cervical myelopathy.

METHODS

In order to provide guidance in clinical decision-making, the authors selectively reviewed the literature, according to the guidelines of the Association of Scientific Medical Societies in Germany.

RESULTS

Cervical myelopathy is a clinical syndrome due to dysfunction of the spinal cord. Its most common cause is spinal cord compression by spondylosis at one or more levels. Its spontaneous clinical course is variable; most patients undergo a slow functional deterioration. Surgical treatment reliably arrests the progression of myelopathy and often even improves the neurological deficits.

DISCUSSION

The available scientific data are too sparse to enable evidence-based treatment of cervical myelopathy. Early surgical intervention is often recommended in the literature. Controversy remains regarding the choice of the appropriate surgical procedure, but there is consensus on the suitable options for many specific clinical situations.