Mild Degenerative Cervical Myelopathy Research Articles

P.109 Machine learning based approach to improving the prediction of neurological deterioration in mild Degenerative Cervical Myelopathy

Background: Degenerative cervical myelopathy (DCM) is the most common form of atraumatic spinal cord injury globally, yet clinical guidelines remain unclear on surgical recommendations for patients with mild forms of DCM. This is in part due to limitations in current MR imaging interpretation and complex mechanisms of neurological deterioration. Supervised machine learning (ML) models can help to identify clinical and imaging indicators of deterioration within mild DCM patients. Methods: 127 MRI scans (T2w, Diffusion Tensor Imaging, and Magnetization transfer scans) accompanied by a series of clinical tests underwent a semi-automated analysis to derive quantitative metrics. Random forest classifier, Support Vector Machine, and Logistic Regression models were trained and tested to predict 6-month neurological deterioration within patients. Results: The ML models performed, on average, better than previous studies with a balanced accuracy ranging between 70-75%. “Advanced” imaging metrics such as diffusion tensor imaging and magnetization transfer scans played an important role in improving model accuracy but only when used near the maximally compressed disc level, suggesting that limited yet targetted imaging metrics support ML model performance. Conclusions: The inclusion of specific, targeted imaging and clinical metrics support ML model performance in predicting neurological deterioration within mild DCM patients.

E.4 Machine learning based patient classification to predict neurological deterioration in mild Degenerative Cervical Myelopathy

Background: Degenerative Cervical Myelopathy (DCM) is the functional derangement of the spinal cord because of compression from degenerate tissues. Typical neurological symptoms of DCM include gait imbalance and upper extremity paresthesia. While it is thought that greater spinal cord compression leads to increased neurological deterioration, our clinical experience suggests a more complex mechanism involving spinal canal diameter (SCD). Methods: 124 MRI scans from 59 non-operative DCM patients underwent manual scoring of cord compression and SCD measurements. Unsupervised machine learning dimensionality reduction techniques and k-means clustering were used to establish patient groups. These patient groups underwent manual inspection of common compression patterns and SCD similarities to define their unique risk criteria. Results: We found that compression pattern is unimportant at SCD extremes (≤14.5 mm or >15.75 mm). Otherwise, stenosis with clear signs of cord compression at two disc levels and stenosis without clear signs of cord compression at two disc levels result in a relatively higher and lower likelihood of deterioration, respectively. We elucidated five patient groups with unique associated risks for neurological deterioration, according to both SCD range and their cord compression pattern. Conclusions: The specific combination of narrow SCD with focal cord compression increases the likelihood of neurological deterioration in non-operative patients with DCM.

Focal compression of the cervical spinal cord alone does not indicate high risk of neurological deterioration in patients with a diagnosis of mild degenerative cervical myelopathy

Degenerative Cervical Myelopathy (DCM) is the functional derangement of the spinal cord resulting from vertebral column spondylotic degeneration. Typical neurological symptoms of DCM include gait imbalance, hand/arm numbness, and upper extremity dexterity loss. Greater spinal cord compression is believed to lead to a higher rate of neurological deterioration, although clinical experience suggests a more complex mechanism involving spinal canal diameter (SCD). In this study, we utilized machine learning clustering to understand the relationship between SCD and different patterns of cord compression (i.e. compression at one disc level, two disc levels, etc.) to identify patient groups at risk of neurological deterioration. 124 MRI scans from 51 non-operative DCM patients were assessed through manual scoring of cord compression and SCD measurements. Dimensionality reduction techniques and k-means clustering established patient groups that were then defined with their unique risk criteria. We found that the compression pattern is unimportant at SCD extremes (≤14.5 mm or > 15.75 mm). Otherwise, severe spinal cord compression at two disc levels increases deterioration likelihood. Notably, if SCD is normal and cord compression is not severe at multiple levels, deterioration likelihood is relatively reduced, even if the spinal cord is experiencing compression. We elucidated five patient groups with their associated risks of deterioration, according to both SCD range and cord compression pattern. Overall, SCD and focal cord compression alone do not reliably predict an increased risk of neurological deterioration. Instead, the specific combination of narrow SCD with multi-level focal cord compression increases the likelihood of neurological deterioration in mild DCM patients.

370 Is There an Optimal Surgical Approach in Degenerative Cervical Myelopathy?: An Individual Participant Data Meta-Analysis

INTRODUCTION: Contradictions exist about impact of anterior vs. posterior surgical approach on outcomes of degenerative cervical myelopathy (DCM). METHODS: Individual patient data of subjects who underwent surgery for DCM was identified from a pooled dataset of the AO Spine CSM-North America, CSM-International, and CSM-Protect clinical studies. Primary outcomes were changes in short form 36 Physical Component Summary score (SF36-PCS) and mJOA score at 12 months. Secondary outcomes were change in total Neck Disability Index (NDI) score and SF36 Mental Component Summary score (SF36-MCS). Two comparison cohorts were created: i) anterior surgery and ii) posterior surgery. One-stage mixed-effects meta-analysis with study and treatment exposure as random effects was performed and reported with mean differences and 95% confidence intervals. A subgroup analysis planned a priori in mild DCM patients (mJOA 15-17) was performed. RESULTS: A total of 979 patients met eligibility criteria. Patients who had anterior decompressive surgery experienced greater improvements at 1yr of follow-up than those who underwent posterior decompressive surgery in SF36-PCS score (adjusted MD 1.57 [95% CI 0.11 to 3.03], p = 0.0348) and NDI score (adjusted MD 3.32 [95% CI 0.58 to 6.05], p = 0.0172). A greater proportion of patients that underwent anterior surgery achieved clinically important recovery of their NDI (OR 1.49 [95% CI 1.15 to 1.93], p = 0.002; aOR 1.46 [95% CI 1.08 to 1.96], p = 0.013) and SF36-PCS scores at 1yr (OR 1.45 [95% CI 1.12 to 1.88], p = 0.004, aOR 1.34 [95% CI 1.00 to 1.80], p = 0.052). In patients with mild DCM (n = 186), patients who underwent anterior decompressive surgery experienced greater improvements in SF36-PCS score, mJOA score, and Neck Disability Index score than posterior surgical patients. CONCLUSIONS: Anterior surgical decompression for DCM is associated with greater improvements in 1yr patient-reported outcomes than posterior surgical decompression.

Degenerative Cervical Myelopathy: An Overview.

Degenerative cervical myelopathy (DCM) is a spinal condition of growing importance due to its increasing prevalence within the ageing population. DCM involves the degeneration of the cervical spine due to various processes such as disc ageing, osteophyte formation, ligament hypertrophy or ossification, as well as coexisting congenital anomalies. This article provides an overview of the literature on DCM and considers areas of focus for future research. A patient with DCM can present with a variety of symptoms ranging from mild hand paraesthesia and loss of dexterity to a more severe presentation of gait disturbance and loss of bowel/bladder control. Hoffman's sign and the inverted brachioradialis reflex are also important signs of this disease. The gold standard imaging modality is MRI which can identify signs of degeneration of the cervical spine. Other modalities include dynamic MRI, myelography, and diffusion tensor imaging. One important scoring system to aid with the diagnosis and categorisation of the severity of DCM is the modified Japanese Orthopaedic Association score. This considers motor, sensory, and bowel/bladder dysfunction, and categorises patients into mild, moderate, or severe DCM. DCM is primarily treated with surgery as this can halt disease progression and may even allow for neurological recovery. The surgical approach will depend on the location of degeneration, the number of cervical levels involved and the pathophysiological process. Surgical approach options include anterior cervical discectomy and fusion, corpectomy, or posterior approach (laminectomy ± fusion). Conservative management is also considered for some patients with mild or non-progressive DCM or for patients where surgery is not an option. Conservative treatment may include physical therapy, traction, or neck immobilisation. Future recommendations include research into the prevalence rate of DCM and if there is a difference between populations. Further research on the benefit of conservative management for patients with mild or non-progressive DCM would be recommended.

A Retrospective Study of Degenerative Cervical Myelopathy and the Surgical Management Within Northern Ireland.

Degenerative cervical myelopathy (DCM) is a condition of growing concern due to its increasing incidence among the ageing population. It involves age-associated pathological changes of the cervical spine that can result in spinal cord compression. This can lead to deficits in motor and sensory function of the upper and lower limbs, issues with balance and dexterity, as well as bladder and bowel disturbance. Patients can be categorised as having mild, moderate, or severe degenerative cervical myelopathy depending on their modified Japanese Orthopaedic Association (mJOA) score. This condition is generally managed surgically; however, patients with mild degenerative cervical myelopathy may be offered or opt for non-surgical treatment initially. The main aim of this study is to evaluate the surgical management of patients with DCM and to ascertain the degree of mJOA improvement from pre-surgery and one-year post-surgery follow-up. The second aim of the study is to explore the demographics within Northern Ireland who are diagnosed with DCM and who undergo surgery. This information could allow for better planning of services in the future for this patient cohort. This is a retrospective review of the surgical management of degenerative cervical myelopathy within the Regional Spinal Orthopaedic Unit in Northern Ireland over three years with one-year follow-up. The data was retrospectively collected from the Fracture Outcome Research Database. A total of 102 patients (10:7, male:female) with DCM were retrospectively evaluated. Exclusion criteria included all patients diagnosed with spinal tumour, fracture, central cord syndrome, and dislocation. Two patients were removed due to incorrect coding of DCM diagnosis and were not included. Key variables assessed were gender, age, symptoms, type of surgery, complications, and MRC score and mJOA score pre-surgery, 48 hours, six months, and one year post surgery. The choice of surgery was guided by the maximal angle of compression, the number of vertebral levels involved, patient comorbidities, and anesthetic risk. The sample consisted of 60 men (58.82%) and 42 women (41.17%) with an average age of 57.17 ± 12.13 years ranging from 27 to 83 years old. Statistical analysis was conducted to explore the effect of time before and after surgery up to one year on the mJOA score. There was a significant difference in mJOA score pre-surgery and at six months and one year post surgery (R = 0.579053, p <0.001). Of the patients,61.8% with a length of stay greater than three days and 71.4% of patients with a length of stay greater than seven days had a posterior approach surgery. A multiple linear regression analysis revealed that the mJOA score pre-surgery and the presence of complications significantly predicted the length of stay post-surgery (β -1.044, p = .011 and β -5.791, p = .028). The first key finding of this study is that the mJOA score tends to improve after surgery for the majority of patients, particularly at six months, which is consistent with the literature. The second key finding is that anterior approach surgery is associated with a lower rate of complications and shorter post-surgery length of stay in hospital compared to posterior approach surgery. The third key finding is that the pre-surgery mJOA score and the presence of complications post surgery significantly predict the post-surgery length of stay.

Increased cranio-caudal spinal cord oscillations are the cardinal pathophysiological change in degenerative cervical myelopathy.

Degenerative cervical myelopathy (DCM) is the most common cause of non-traumatic incomplete spinal cord injury, but its pathophysiology is poorly understood. As spinal cord compression observed in standard MRI often fails to explain a patient's status, new diagnostic techniques to assess DCM are one of the research priorities. Minor cardiac-related cranio-caudal oscillations of the cervical spinal cord are observed by phase-contrast MRI (PC-MRI) in healthy controls (HCs), while they become pathologically increased in patients suffering from degenerative cervical myelopathy. Whether transversal oscillations (i.e., anterior-posterior and right-left) also change in DCM patients is not known. We assessed spinal cord motion simultaneously in all three spatial directions (i.e., cranio-caudal, anterior-posterior, and right-left) using sagittal PC-MRI and compared physiological oscillations in 18 HCs to pathological changes in 72 DCM patients with spinal canal stenosis. The parameter of interest was the amplitude of the velocity signal (i.e., maximum positive to maximum negative peak) during the cardiac cycle. Most patients suffered from mild DCM (mJOA score 16 (14-18) points), and the majority (68.1%) presented with multisegmental stenosis. The spinal canal was considerably constricted in DCM patients in all segments compared to HCs. Under physiological conditions in HCs, the cervical spinal cord oscillates in the cranio-caudal and anterior-posterior directions, while right-left motion was marginal [e.g., segment C5 amplitudes: cranio-caudal: 0.40 (0.27-0.48) cm/s; anterior-posterior: 0.18 (0.16-0.29) cm/s; right-left: 0.10 (0.08-0.13) cm/s]. Compared to HCs, DCM patients presented with considerably increased cranio-caudal oscillations due to the cardinal pathophysiologic change in non-stenotic [e.g., segment C5 amplitudes: 0.79 (0.49-1.32) cm/s] and stenotic segments [.g., segment C5 amplitudes: 0.99 (0.69-1.42) cm/s]). In contrast, right-left [e.g., segment C5 amplitudes: non-stenotic segment: 0.20 (0.13-0.32) cm/s; stenotic segment: 0.11 (0.09-0.18) cm/s] and anterior-posterior oscillations [e.g., segment C5 amplitudes: non-stenotic segment: 0.26 (0.15-0.45) cm/s; stenotic segment: 0.11 (0.09-0.18) cm/s] remained on low magnitudes comparable to HCs. Increased cranio-caudal oscillations of the cervical cord are the cardinal pathophysiologic change and can be quantified using PC-MRI in DCM patients. This study addresses spinal cord oscillations as a relevant biomarker reflecting dynamic mechanical cord stress in DCM patients, potentially contributing to a loss of function.

Early surgery compared to nonoperative management for mild degenerative cervical myelopathy: a cost-utility analysis

Early surgery compared to nonoperative management for mild degenerative cervical myelopathy: a cost-utility analysis

Early surgery compared to nonoperative management for mild degenerative cervical myelopathy: a cost-utility analysis

BACKGROUND CONTEXTDegenerative cervical myelopathy (DCM) is a form of acquired spinal cord compression and contributes to reduced quality of life secondary to neurological dysfunction and pain. There remains uncertainty regarding optimal management for individuals with mild myelopathy. Specifically, owing to lacking long-term natural history studies in this population, we do not know whether these individuals should be treated with initial surgery or observation. PURPOSEWe sought to perform a cost-utility analysis to examine early surgery for mild degenerative cervical myelopathy from the healthcare payer perspective. STUDY DESIGN/SETTINGWe utilized data from the prospective observational cohorts included in the Cervical Spondylotic Myelopathy AO Spine International and North America studies to determine health related quality of life estimates and clinical myelopathy outcomes. PATIENT SAMPLEWe recruited all patients that underwent surgery for DCM enrolled in the Cervical Spondylotic Myelopathy AO Spine International and North America studies between December 2005 and January 2011. OUTCOME MEASURESClinical assessment measures were obtained using the Modified Japanese Orthopedic Association scale and health-related quality of life measures were obtained using the Short Form-6D utility score at baseline (preoperative), 6 months, 12 months and 24 months postsurgery. Cost measures inflated to January 2015 values were obtained using pooled estimates from the hospital payer perspective for surgical patients. METHODSWe employed a Markov state transition model with Monte Carlo microsimulation using a lifetime horizon to obtain an incremental cost utility ratio associated with early surgery for mild myelopathy. Parameter uncertainty was assessed through deterministic means using one-way and two-way sensitivity analyses and probabilistically using parameter estimate distributions with microsimulation (10,000 trials). Costs and utilities were discounted at 3% per annum. RESULTSInitial surgery for mild degenerative cervical myelopathy was associated with an incremental lifetime increase of 1.26 quality-adjusted life years (QALY) compared to observation. The associated cost incurred to the healthcare payer over a lifetime horizon was $12,894.56, resulting in a lifetime incremental cost-utility ratio of $10,250.71/QALY. Utilizing a willingness to pay threshold in keeping with the World Health Organization definition of "very cost-effective" ($54,000 CDN), the probabilistic sensitivity analysis demonstrated that 100% of cases were cost-effective. CONCLUSIONSSurgery compared to initial observation for mild degenerative cervical myelopathy was cost-effective from the Canadian healthcare payer perspective and was associated with lifetime gains in health-related quality of life.

433 Trajectory-based Classification of Recovery Potential in Mild Degenerative Cervical Myelopathy: Analysis of a Prospective Multicentre Dataset of 1047 Patients

INTRODUCTION: Degenerative Cervical Myelopathy (DCM) is the leading cause of disability secondary to a spinal pathology in adults. There exists clinical equipoise between surgery and conservative management with monitoring for patients with mild DCM. METHODS: A harmonized dataset was developed from the AOSpine North America, AOSpine International datasets as well as the CSM-Protect trial (N:1047). DCM patients (mJOA ≥15) were selected from the harmonized dataset. Latent class trajectory modeling was applied to classify patients into distinct trajectories. The optimal number of trajectories were chosen based on i) least Bayesian Information Criterion; ii) posterior probability &gt;0.70; iii) odds of correct classification &gt;5; and concordance between the estimated and actual proportion of patients assigned to a class. Predictors of recovery trajectories were identified using descriptive statistics and logistic regression on baseline variables. RESULTS: Two distinct recovery trajectories were revealed from our analysis. Good recovery trajectory had patients that improved to near-maximal mJOA scores within 12 months. Functional decline trajectory was characterized by a decline in more than two mJOA points over 12 months. There were 33 patients (15.6%) that followed functional decline and 179 that showed good recovery (84.4%). Demographic factors associated with following a functional decline trajectory included older age, hypertension, and higher baseline Nurick score. Posterior laminectomy and fusion was associated with functional decline compared to anterior fixation. CONCLUSIONS: Mild DCM can be classified into one of two distinct subpopulations with different recovery trajectories. This study lends support to the heterogeneity of mild DCM and classifying the clinical course of mild DCM based on defined clinical phenotypes rather than baseline severity of myelopathy alone. We also discovered that anterior surgery is associated with better neurological recovery in the context of mild DCM patients.

Differences in spinal cord biomechanics after laminectomy, laminoplasty, and laminectomy with fusion for degenerative cervical myelopathy.

Spinal cord stress/strain during neck motion contributes to spinal cord dysfunction in degenerative cervical myelopathy (DCM), yet the effect of surgery on spinal cord biomechanics is unknown. It is expected that motion-preserving and fusion surgeries for DCM will have distinct effects on spinal cord biomechanics. The aim of this study was to compare changes in spinal cord biomechanics after laminectomy with fusion, laminectomy, and laminoplasty using a patient-specific finite element model (FEM) for DCM. A patient-specific FEM of the cervical spine and spinal cord was created using MRI from a subject with mild DCM. Multilevel laminectomy with fusion, laminectomy, and laminoplasty were simulated for DCM using the patient-specific FEM. Spinal cord von Mises stress and maximum principal strain during neck flexion-extension, lateral bending, and axial rotation were recorded. Segmental range of motion, intradiscal pressure, and capsular ligament strain were also measured. FEM outputs were calculated as a change with respect to the preoperative values and compared between the three models. Across the surgical levels, spinal cord stress increased after laminectomy for neck flexion (+50%), neck extension (+37.8%), and axial rotation (+23%). Similarly, spinal cord strain increased in neck extension (+118.4%) and axial rotation (+75.1%) after laminectomy. Laminoplasty was associated with greater spinal cord stress in neck flexion (+57.4%) and increased strain in lateral bending (+56.7%) and axial rotation (+20.9%). Compared with laminectomy and laminoplasty, spinal cord biomechanics for laminectomy with fusion revealed significantly reduced median extension stress (13.7 kPa vs 9.7 kPa, p = 0.03), lateral bending strain (0.01 vs 0.007, p = 0.007), axial rotation stress (3.7 kPa vs 2.1 kPa, p = 0.04), and axial rotation strain (0.017 vs 0.009, p = 0.04). Spinal cord strain decreased in neck flexion in all three models, yet spinal cord stress increased with neck flexion for laminectomy and laminoplasty. Changes in spinal cord biomechanics for laminoplasty parallel those for laminectomy with fusion except during neck flexion, lateral bending, and axial rotation. Compared with motion-preserving approaches such as laminectomy and laminoplasty, laminectomy with fusion was associated with the lowest spinal cord stress and strain in flexion-extension, lateral bending, and axial rotation of the neck.

Predictors of Outcome After Surgical Decompression for mild degenerative Cervical Myelopathy -A Systematic Review.

Systematic Reviews. To investigate predictors of surgical outcomes for mild Degenerative Cervical Myelopathy (DCM) by reviewing all related studies conducted at this point. An electronic search was carried out in PubMed, EMBASE, Scopus, and Web of Science until June 23, 2021. Full-text articles reporting surgical outcome predictors of mild DCM cases were eligible. We included studies with mild DCM which was defined as a modified Japanese Orthopaedic Association score of 15 to 17 or a Japanese Orthopaedic Association score of 13 to 16. Independent reviewers screened all the records, and discrepancies between the reviewers were solved in a session with the senior author. For risk of bias assessment, RoB 2 tool was used for randomized clinical trials and ROBINS-I for non-randomized studies. After screening 6 087 manuscripts, only 8 studies met the inclusion criteria. Lower pre-operative mJOA scores and quality-of-life measurement scores were reported by multiple studies to predict better surgical outcomes compared to other groups. High-intensity pre-operative T2 magnetic resonance imaging (MRI) was also reported to predict poor outcomes. Neck pain before intervention resulted in improved patient-reported outcomes. Two studies also reported motor symptoms prior to surgery as outcome predictors. Lower quality of life before surgery, neck pain, lower pre-operative mJOA scores, motor symptoms before surgery, female gender, gastrointestinal comorbidities, surgical procedure and surgeon's experience with specific techniques, and high signal intensity of cord in T2 MRI were the surgical outcome predictors reported in the literature. Lower Quality of Life (QoL) score and neck prior to surgery were reported as predictors of the more improved outcome, but high cord signal intensity in T2 MRI was reported as an unfavorable outcome predictor.

Analysis of recovery trajectories in degenerative cervical myelopathy to facilitate improved patient counseling and individualized treatment recommendations.

There is a need to better understand and predict postsurgical outcomes for degenerative cervical myelopathy (DCM) patients, particularly to support treatment decisions for patients with mild DCM. The goal of this study was to identify and predict outcome trajectories for DCM patients up to 2 years postsurgery. The authors analyzed two North American multicenter prospective DCM studies (n = 757). Functional recovery and physical health component quality of life were assessed in DCM patients at baseline, 6 months, and 1 and 2 years postoperatively using the modified Japanese Orthopaedic Association (mJOA) score and Physical Component Summary (PCS) of the SF-36, respectively. Group-based trajectory modeling was used to identify recovery trajectories for mild, moderate, and severe DCM. Prediction models for recovery trajectories were developed and validated in bootstrap resamples. Two recovery trajectories were identified for the functional and physical components of quality of life: good recovery and marginal recovery. Depending on outcome and myelopathy severity, one-half to three-fourths of the study patients followed the good recovery trajectory characterized by improvement in mJOA and PCS scores over time. The remaining one-half to one-fourth of patients followed the marginal recovery trajectory, experiencing little improvement and, in certain cases, worsening postoperatively. The prediction model for mild DCM had an area under the curve of 0.72 (95% CI 0.65-0.80), with preoperative neck pain, smoking, and posterior surgical approach noted as dominant predictors of marginal recovery. Surgically treated DCM patients follow distinct recovery trajectories in the first 2 years postoperatively. While most patients experience substantial improvement, a significant minority experience little improvement or worsening. The ability to predict DCM patient recovery trajectories in the preoperative setting facilitates the formulation of individualized treatment recommendations for patients with mild symptoms.

Myelopathy disability index: establishing criteria for mild, moderate and severe impairment in patients with degenerative cervical myelopathy.

To find the cut-off values in the Myelopathy Disability Index (MDI) that will allow us to classify the severity of Degenerative Cervical Myelopathy (DCM) into mild, moderate and severe. Cross-sectional study with prospective data collection, with a total of 64 patients diagnosed with Degenerative Cervical Myelopathy (DCM). Anthropometric, diagnostic, neurological, functional and quality of life variables were collected. A Receiver Operating Curve (ROC) was performed. The cut-off points were validated by comparing the functional status of patients in the 3 groups and their Nurick scores. Sixty-four patients (23 women) with a mean age of 61.97 (SD 11.57) participated in this study. The majority of patients were Nurick I (28.13%) and Nurick II (32.81%). The medium MDI was 7.36 (SD 6.66) and the mJOA was 14.08 (SD 2.57). The mild-moderate cut-off value was between 4 and 5, with an Area Under the Curve (AUC) of 0.805, sensitivity of 0.853 and specificity of 0.6. For moderate-severe, the cut-off value obtained was between 7 and 8, with an AUC of 0.862, sensitivity of 0.857 and specificity of 0.684. Patients with greater severity had significantly lower functionality, with a P-value of 0.004 in the 30 Metre Walking Test and 0.005 in the Nine-Hole Peg Test. Established severity groups were also significantly related to the different categories of the Nurick score (P-value = 0.000). MDI values between 0 and 4 correspond to mild DCM, between 5 and 7 would be moderate DCM and from 8 to 30 indicate severe DCM.

Management of Mild Degenerative Cervical Myelopathy and Asymptomatic Spinal Cord Compression: An International Survey

Management of Mild Degenerative Cervical Myelopathy and Asymptomatic Spinal Cord Compression: An International Survey

Evolution of brain functional plasticity associated with increasing symptom severity in degenerative cervical myelopathy.

SummaryBackgroundAdvanced imaging modalities have helped elucidate the cerebral alterations associated with neurological impairment caused by degenerative cervical myelopathy (DCM), but it remains unknown how brain functional network changes at different stages of myelopathy severity in DCM patients, and if patterns in network connectivity can be used to predict transition to more myelopathic stages of DCM.MethodsThis pilot cross-sectional study, which involves the collection of resting-state functional MRI (rs-fMRI) images and the modified Japanese Orthopedic Association (mJOA) score, enrolled 116 participants (99 patients and 17 healthy controls) from 2016 to 2021. The patient cohort included 21patients with asymptomatic spinal cord compression, 48 mild DCM patients, and 20 moderate or severe DCM patients. Functional connectivity networks were quantified for all participants, and the transition matrices were quantified to determine the differences in network connectivity through increasingly myelopathic stages of DCM. Additionally, a link prediction model was used to determine whether more severe stages of DCM can be predicted from less symptomatic stages using the transition matrices.FindingsResults indicated interruptions in most connections within the sensorimotor network in conjunction with spinal cord compression, while compensatory connectivity was observed within and between primary and secondary sensorimotor regions, subcortical regions, visuospatial regions including the cuneus, as well as the brainstem and cerebellum. A link prediction model achieved an excellent predictive performance in estimating connectivity of more severe myelopathic stages of DCM, with the highest area under the receiver operator curve (AUC) of 0.927 for predicting mild DCM from patients with asymptomatic spinal cord compression.InterpretationA series of predictable changes in functional connectivity occur throughout the stages of DCM pathogenesis. The brainstem and cerebellum appear highly influential in optimizing sensorimotor function during worsening myelopathy. The link predication model can inclusively estimate brain alterations associated with myelopathy severity.FundingNIH/NINDS grants (1R01NS078494-01A1, and 2R01NS078494).

139. Quantitative microstructural MRI accurately predicts the likelihood of patients with degenerative cervical myelopathy requiring surgical intervention

<h3>BACKGROUND CONTEXT</h3> The definitive management of degenerative cervical myelopathy (DCM) is surgical decompression in moderate to severe cases. The evidence for early surgical intervention in mild DCM patients is less definitive and therefore, current guidelines are less clear on the relative merits of operative vs nonoperative intervention in this group of patients. According to the best available evidence, anywhere from 20%-62% of patients with mild DCM will deteriorate within 6 years; however, there is no reliable way to predict such a deterioration. However, advances in microstructural MRI may afford a novel approach to address this knowledge gap since these imaging techniques allow one to assess pathological changes such as demyelination, scarring and axonal/neuronal loss. <h3>PURPOSE</h3> Using prospectively collected data, we investigate whether quantitative MRI (qMRI) metrics can predict which patients with DCM are likely to deteriorate clinically and require surgery within one year of presentation. <h3>STUDY DESIGN/SETTING</h3> Prospective cohort study. <h3>PATIENT SAMPLE</h3> This study included 58 DCM patients (33 mild, 15 moderate and 10 severe). <h3>OUTCOME MEASURES</h3> Quantitative MRI metrics and mJOA. <h3>METHODS</h3> Data were stratified into patients who required surgery within one year of follow-up and those who remained stable and continued in the nonoperative group. MRI Acquisition and Image Processing: All patients underwent a multiparametric qMRI scan protocol including diffusion tensor (DTI), magnetization transfer (MT) and T2* weighted imaging at the initial visit. Quantitative metrics including cross sectional area (CSA), fractional anisotropy (FA), magnetization transfer ratio (MTR), and T2* white matter to gray matter ratio (T2*WI WM/GM) were measured in the cervical spine at the rostral, caudal and most compressed levels (MCL). Statistical analysis multivariable logistic regression was performed using baseline FA, MTR and T2*WI WM/GM in the rostral spine and CSA at the MCL as predictor variables. Surgical decompression at one year was used as the dependent variable. Model discrimination and reliability were measured using c-index and Brier's score respectively. Validation and calibration were performed using bootstrap method with 100 repetitions. <h3>RESULTS</h3> A total of 33 mild (mJOA 15-17), 15 moderate (mJOA 12-14) and 10 severe (mJOA 0-11) DCM patients were included in the study. Twenty-eight patients had undergone surgical decompresion at One-year follow-up, whereas the other 28 remained in nonoperative managment. Baseline qMRI was able to identify patients requiring surgery, with an accuracy of 81.6% (AUC or c-index). The model showed good reliability with a Brier score of 0.18 and Somers' Dxy rank correlation of 0.63. Calibration using bootstrap method showed overall good predictive ability with slight over prediction at higher observed probability of surgery. <h3>CONCLUSIONS</h3> Baseline quantitative MRI is able to accurately predict the likelihood of deterioration and surgical intervention in DCM patients. It can potentially play an important role in screening patient populations for surgical candidates or those who are at high risk of deterioration. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Comparison of axial and sagittal spinal cord motion measurements in degenerative cervical myelopathy.

The timing of decision-making for a surgical intervention in patients with mild degenerative cervical myelopathy (DCM) is challenging. Spinal cord motion phase contrast MRI (PC-MRI) measurements can reveal the extent of dynamic mechanical strain on the spinal cord to potentially identify high-risk patients. This study aims to determine the comparability of axial and sagittal PC-MRI measurements of spinal cord motion with the prospect of improving the clinical workup. Sixty-four DCM patients underwent a PC-MRI scan assessing spinal cord motion. The agreement of axial and sagittal measurements was determined by means of intraclass correlation coefficients (ICCs) and Bland-Altman analyses. The comparability of axial and sagittal PC-MRI measurements was good to excellent at all cervical levels (ICCs motion amplitude: .810-.940; p&lt;.001). Significant differences between axial and sagittal amplitude values could be found at segments C3 and C4, while its magnitude was low (C3: 0.07±0.19cm/second; C4: -0.12±0.30cm/second). Bland-Altman analysis showed a good agreement between axial and sagittal PC-MRI scans (coefficients of repeatability: minimum -0.23cm/second at C2; maximum -0.58cm/second at C4). Subgroup analysis regarding anatomic conditions (stenotic vs. nonstenotic segments) and different velocity encoding (2 vs. 3cm/second) showed comparable results. This study demonstrates good comparability between axial and sagittal spinal cord motion measurements in DCM patients. To this end, axial and sagittal PC-MRI are both accurate and sensitive in detecting pathologic cord motion. Therefore, such measures could identify high-risk patients and improve clinical decision-making (ie, timing of decompression).

Proposing a Framework to Understand the Role of Imaging in Degenerative Cervical Myelopathy: Enhancement of MRI Protocols Needed for Accurate Diagnosis and Evaluation.

Proposing a Framework to Understand the Role of Imaging in Degenerative Cervical Myelopathy: Enhancement of MRI Protocols Needed for Accurate Diagnosis and Evaluation.

Degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. Its prevalence is increasing as a result of population aging. The diagnosis of DCM is often delayed or overlooked, resulting in secondary neurologic morbidity. The natural course of DCM typically presents as a gradual neurological deterioration, with symptoms ranging from muscle weakness to complete paralysis, with variable degrees of sensory deficits and sphincter dysfunction. Magnetic resonance imaging (MRI) and electrophysiological studies allow the assessment of spinal cord function and its structural damage to determine treatment and clinical outcomes. All patients with signs and symptoms consistent with DCM should be referred to a spine surgeon for assessment and tailored treatment. Those patients with mild DCM can be managed non-operatively but require close monitoring and education about potentially alarming signs and symptoms. Surgery is not currently recommended for asymptomatic patients with evidence of spinal cord compression or cervical spinal stenosis on MRI, but they require a structured follow-up. Patients with moderate or severe DCM require surgical decompression to avoid further progression. The objective of this review is to raise awareness of degenerative cervical myelopathy and its increasing prevalence as well as to aid non-surgical healthcare workers for a timely diagnosis and management of this disabling condition.