Preoperative Computed Tomography Myelography Parameters as Predictors of Outcome in Patients With Degenerative Cervical Myelopathy: Results of a Systematic Review

[Analysis of imaging characteristics and effectiveness of cervical spondylotic myelopathy with cervical kyphosis]

Objective

To investigate the imaging characteristics of cervical kyphosis and spinal cord compression in cervical spondylotic myelopathy (CSM) with cervical kyphosis and the influence on effectiveness.

Methods

The clinical data of 36 patients with single-segment CSM with cervical kyphosis who were admitted between January 2020 and December 2022 and met the selection criteria were retrospectively analyzed. The patients were divided into 3 groups according to the positional relationship between the kyphosis focal on cervical spine X-ray film and the spinal cord compression point on MRI: the same group (group A, 20 cases, both points were in the same position), the adjacent group (group B, 10 cases, both points were located adjacent to each other), and the separated group (group C, 6 cases, both points were located >1 vertebra away from each other). There was no significant difference between groups ( P>0.05) in baseline data such as gender, age, body mass index, lesion segment, disease duration, and preoperative C 2-7 angle, C 2-7 sagittal vertical axis (C 2-7 SVA), C 7 slope (C 7S), kyphotic Cobb angle, fusion segment height, and Japanese Orthopedic Association (JOA) score. The patients underwent single-segment anterior cervical discectomy with fusion (ACDF). The occurrence of postoperative complications was recorded; preoperatively and at last follow-up, the patients' neurological function was evaluated using the JOA score, and the sagittal parameters (C 2-7 angle, C 2-7 SVA, C 7S, kyphotic Cobb angle, and height of the fused segments) were measured on cervical spine X-ray films and MRI and the correction rate of the cervical kyphosis was calculated; the correlation between changes in cervical sagittal parameters before and after operation and the JOA score improvement rate was analyzed using Pearson correlation analysis.

Results

In 36 patients, only 1 case of dysphagia occurred in group A, and the dysphagia symptoms disappeared at 3 days after operation, and the remaining patients had no surgery-related complications during the hospitalization. All patients were followed up 12-42 months, with a mean of 20.1 months; the difference in follow-up time between the groups was not significant ( P>0.05). At last follow-up, all the imaging indicators and JOA scores of patients in the 3 groups were significantly improved when compared with preoperative ones ( P<0.05). The correction rate of cervical kyphosis in group A was significantly better than that in group C, and the improvement rate of JOA score was significantly better than that in groups B and C, all showing significant differences ( P<0.05), and there was no significant difference between the other groups ( P>0.05). The correlation analysis showed that the improvement rate of JOA score was negatively correlated with C 2-7 angle and kyphotic Cobb angle at last follow-up ( r=-0.424, P=0.010; r=-0.573, P<0.001), and positively correlated with the C 7S and correction rate of cervical kyphosis at last follow-up ( r=0.336, P=0.045; r=0.587, P<0.001), and no correlation with the remaining indicators ( P>0.05).

Conclusion

There are three main positional relationships between the cervical kyphosis focal and the spinal cord compression point on imaging, and they have different impacts on the effectiveness and sagittal parameters after ACDF, and those with the same position cervical kyphosis focal and spinal cord compression point have the best improvement in effectiveness and sagittal parameters.

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.

Diagnostic and prognostic significance of preoperative evoked potential tests in degenerative cervical myelopathy

BACKGROUND CONTEXT

Decompression surgery is a treatment option for patients with degenerative cervical myelopathy (DCM). Surgical decisions primarily depend on clinical symptoms and radiological examinations. The diagnostic and prognostic significance of evoked potential tests for surgical outcomes in patients with DCM has not been thoroughly examined.

PURPOSE

To identify the diagnostic and prognostic significance of preoperative evoked potential tests in patients with DCM who underwent decompression surgery.

STUDY DESIGN

This was a retrospective observational study.

PATIENT SAMPLE

One hundred two consecutive patients who underwent evoked potential tests and surgical treatment between January 2016 and December 2020 in a single spine center and had a minimum follow-up of 6 months.

OUTCOME MEASURES

Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery.

METHODS

This study evaluated the preoperative central motor conduction time (CMCT), somatosensory evoked potentials, and Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery.

RESULTS

Abnormal CMCT findings were observed in 94 patients (92.2%). Abnormal somatosensory evoked potentials were observed in 77 patients (75.5%). There was a statistically significant correlation between preoperative JOA score and abductor pollicis brevis (APB)-CMCT (r=-0.546, p=.001), tibialis anterior (TA)-CMCT (r=-0.517, p<.001), median nerve (MN)-SSEP (r=-0.353, p=.001), and tibial nerve (TN)-SSEP (r=-0.349, p=.003). There were significant differences in recovery rates associated with diabetes mellitus (DM), preoperative severity of myelopathy, TA-CMCT, MN-SSEP, and TN-SSEP. Stepwise multiple regression analysis showed that the major factors affecting the clinical outcomes were TN-SSEP (β=0.327, p=.004), preoperative JOA score (β=0.278, p=.012), and DM (β=0.241, p=.025).

CONCLUSIONS

Evoked potential testing is a functional diagnostic tool that can indicate the severity of myelopathic symptoms in patients with DCM. Additionally, preoperative TN-SSEP may have significant prognostic value in predicting postoperative clinical outcomes. Thus, preoperative evoked potential tests could be helpful for determining suitable surgical treatment candidates and forecasting postoperative prognosis.

The imaging of cervical spondylotic myeloradiculopathy

This review provides a detailed description of the imaging features of cervical spondylotic myelopathy and radiculopathy, with a focus on MRI. Where relevant, we will outline grading systems of vertebral central canal and foraminal stenosis. Whilst post-operative appearances of the cervical spine are outside the scope of this paper, we will touch on imaging features recognised as predictors of clinical outcome and neurological recovery. This paper will serve as a reference for both radiologists and clinicians involved in the care of patients with cervical spondylotic myeloradiculopathy.

Radiographic Parameters in Cervical Myelopathy: Review of Current Literature

STUDY DESIGN

This was a narrative review.

OBJECTIVES

Provide a comprehensive review of radiographic alignment parameters and their effect on procedure selection, surgical decision-making, and clinical outcomes for the treatment of cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

The use of radiographic parameters to predict prognosis and surgical outcomes in patients with CSM is an evolving field given the complex presentation of patients with this condition.

METHODS

A literature search was conducted using PubMed for surgical treatment of CSM, with an emphasis on cervical radiographic parameters and clinical outcomes.

RESULTS

The principal goals of spine surgery can be broken down into decompression, stabilization, and restoration of alignment. The principle of restoring balance takes careful preoperative planning and attention to radiographic parameters including cervical lordosis, C2-C7 sagittal vertical axis, neck tilt, thoracic inlet angle, T1 slope, K-line, and modified K-line. Surgical interventions for CSM include anterior cervical discectomy and fusion, posterior cervical fusion, or laminoplasty and careful consideration of radiographic measures guide surgical decision-making is essential to ensure optimal outcomes.

CONCLUSION

Utilization of key radiographic parameters in surgical planning and decision-making allows surgeons to optimize clinical outcomes for CSM.

LEVEL OF EVIDENCE

Level V.

Cervical Spondylotic Myelopathy: Natural Course and the Value of Diagnostic Techniques -WFNS Spine Committee Recommendations

Objective

This study presents the results of a systematic literature review conducted to determine most up-to-date information on the natural outcome of cervical spondylotic myelopathy (CSM) and the most reliable diagnostic techniques.

Methods

A literature search was performed for articles published during the last 10 years.

Results

The natural course of patients with cervical stenosis and signs of myelopathy is quite variable. In patients with no symptoms, but significant stenosis, the risk of developing myelopathy with cervical stenosis is approximately 3% per year. Myelopathic signs are useful for the clinical diagnosis of CSM. However, they are not highly sensitive and may be absent in approximately one-fifth of patients with myelopathy. The electrophysiological tests to be used in CSM patients are motor evoked potential (MEP), spinal cord evoked potential, somatosensory evoked potential, and electromyography (EMG). The differential diagnosis of CSM from other neurological conditions can be accomplished by those tests. MEP and EMG monitoring are useful to reduce C5 root palsy during CSM surgery. Notable spinal cord T2 hyperintensity on cervical magnetic resonance imaging (MRI) is correlated with a worse outcome, whereas lighter signal changes may predict better outcomes. T1 hypointensity should be considered a sign of more advanced disease.

Conclusion

The natural course of CSM is quite variable. Signal changes on MRI and some electrophysiological tests are valuable adjuncts to diagnosis.