A New Framework for Investigating the Biological Basis of Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 5]: Mechanical Stress, Vulnerability and Time

Outcomes for Degenerative Cervical Myelopathy Following Implementation of the AO Spine International Guidelines: A Single-Centre Service Evaluation

IntroductionDegenerative cervical myelopathy (DCM) is a syndrome of symptomatic cervical spinal cord compression due to degenerative spinal changes. Until recently there was no formal consensus on exactly which patients are suitable for surgical or conservative management. The AO Spine international guidelines were introduced to address this issue, based on the best available current evidence. However, their implementation into routine clinical practice has not yet been reported. The objective was to evaluate surgical outcomes following the implementation of the AO Spine guidelines at our spinal neurosurgical centre.MethodsA service evaluation was conducted using data collected from electronic healthcare records for 259 patients, with outcomes of interest including change in mJOA score and complications. Data from 193 patients were included in the final analysis.ResultsThere was a mean improvement of the mJOA score by 1.53 points, 1.44 point and 1.92 points at post-operative intervals of 3 months (P < .001), 6 months (P < .001) and 12 months (P < .001). The percentage (number) of patients whose increase in mJOA score was greater than or equal to the minimal clinically importance difference (MCID) was 41% (44/107), 34% (33/96) and 43% (49/114) at these respective time intervals. Intraoperative complications occurred in 28 patients (11.7%). No association was found between BMI and postoperative change in mJOA score.ConclusionOur results are comparable to those from best practice data and suggest adherence to international guidelines provides a service that promotes meaningful recovery for patients with DCM. Therefore, our results offer support for implementation of the AO Spine international guidelines in clinical practice.

Impact of hypertension in diabetes on surgical outcomes after cervical laminoplasty - a retrospective, multi-institutional study of 1002 patients

PURPOSE

This study aimed to elucidate the association between comorbid hypertension (HT) and diabetes mellitus (DM) (HT in DM) and clinical outcomes after cervical laminoplasty.

METHODS

This retrospective multi-institutional study enrolled patients who underwent laminoplasty between 2008 and 2017. The primary outcome was the recovery rate of JOA score. The secondary outcome was in-hospital all-cause postoperative complications.

RESULTS

This study included 1002 patients (mean age, 66 years; 30% women) who were divided into 4 groups based on the presence of medically-treated HT and/or DM. The overall incidence of DM was 17%, and the prevalence of HT was 47% in diabetic patients. Patients with HT in DM showed similar preoperative JOA scores compared to those without both HT and DM. However, patients with HT in DM showed poorer postoperative JOA scores and worse JOA-RR (non-HT/DM, 48%; DM, 43%; HT, 37%; HT in DM, 28%; p < 0.05). Patients with HT in DM tended to have a higher risk of postoperative complications (2.5%, 5.4%, 3.0%, and 7.4%; p = 0.09), especially C5 palsy (0.8%, 3.0%, 1.7%, and 4.9%; p = 0.04). After adjusting confounders, the presence of HT in DM was an independent risk factor for failure to achieve the JOA-RR MCID (JOA-RR < 42%) (OR = 3.6).

CONCLUSIONS

Approximately half of patients with DM had HT. HT in DM was closely associated with unfavorable surgical outcomes, including an increased incidence of in-hospital postoperative complications and an elevated risk of C5 palsy. In contrast, patients with DM alone demonstrated relatively favorable outcomes.

A Controlled Single-Centre Pilot Study to Evaluate the Effect of Prophylactic Surgery in Asymptomatic Degenerative Cervical Cord Compression

Study DesignSingle-centre controlled pilot study.ObjectivesTo evaluate the effect of prophylactic surgery and to review the biases of a therapeutic trial in asymptomatic degenerative cervical cord compression (ADCC) patients.MethodsPatients with ADCC and at least 1 predictor of progression to symptomatic degenerative cervical cord myelopathy (DCM) were offered either prophylactic surgery or standard structured rehabilitation. Recruited patients were clinically followed to detect the development of symptomatic DCM.ResultsForty-one patients treated surgically and 68 patients treated non-surgically completed the minimum 36 months' follow-up; 3 recruited patients were lost from evaluation. The surgical group had a higher Neck Disability Index score and more severe MRI compression. A matched subgroup of 41 non-surgical patients was created to reduce potential bias. During the follow-up period we observed progression to symptomatic DCM in 1 surgical case (2.4%) compared to 9 patients in the non-surgical group (13.2%, P = 0.054) and 7 cases in the matched non-surgical group (17.1%, P = 0.029). We observed non-serious early postoperative complications in 4 patients, which resolved spontaneously or after surgical revision. In 9 patients with progression to DCM, the myelopathy was mild with mJOA scale 15-17. One patient in the non-surgical group and 1 patient in the surgical group who progressed to DCM underwent surgery with a good outcome.ConclusionsProphylactic surgery led to a significant decrease in proportion of ADCC patients with progression to DCM. The results justify the organisation of a large randomized multicentre trial that may demonstrate the benefit of prophylactic surgery in ADCC patients.

Previous Surgical Exposure and the Onset of Degenerative Cervical Myelopathy: A Propensity-Matched Case-Control Analysis Nested Within the UK Biobank Cohort

STUDY DESIGN

Case-control study.

OBJECTIVES

Degenerative Cervical Myelopathy (DCM) is a progressive neurological condition caused by mechanical stress on the cervical spine. Surgical exposure in the preceding months to a DCM diagnosis is a common theme of Patient and Public Involvement (PPI) discussions. Such a relationship has biological plausibility (e.g. neck positioning, cord perfusion) but evidence to support this association is lacking.

METHODS

We analysed UK Hospital Episode Statistics (HES) data for participants in the UK BioBank cohort. We defined cases as those episodes with a primary diagnosis of DCM and generated controls using non-DCM HES episodes. Cases and controls were propensity score-matched by age, sex and date of episode, and a directed acyclic graph was used to robustly control for confounders. We defined the exposure as any surgical procedure under general or regional anaesthetic occurring within the 6-24 months prior to the episode.

RESULTS

We analysed 806 DCM and 2287432 non-DCM hospital episodes. On multivariable logistic regression analysis, the odds ratio (95% CI) for the effect of a binarised (0 vs ≥ 1) exposure on risk of developing DCM was 1.20 (1.02-1.41), and for categorised (0 vs 1 and 0 vs ≥ 2) exposure was 1.11 (0.882-1.39) & 1.33 (1.075-1.65).

CONCLUSIONS

This study supports the patient narrative of surgery as a risk factor for the development of DCM. The association displays temporality, dose-response relationship, and biological plausibility. Further work is needed to confirm this in other cohorts, explore mediating mechanisms, and identify those at greatest risk.

Degenerative Cervical Myelopathy Awareness in Primary Care: UK National Cross-Sectional Survey of General Practitioners

BACKGROUND

Degenerative cervical myelopathy (DCM) is a progressive neurological condition, characterized by spinal cord injury secondary to degenerative changes in the spine. Misdiagnosis in primary care forms part of a complex picture leading to an average diagnostic delay of 2 years. This leads to potentially preventable and permanent disability. A lack of awareness secondary to deficits in postgraduate education may contribute to these delays.

OBJECTIVE

This study aims to assess the awareness of DCM in the setting of general practice.

METHODS

General practitioners completed a quantitative web-based cross-sectional questionnaire. The 17-item questionnaire captured data regarding demographics, subjective awareness, and objective knowledge. The questionnaire was disseminated via professional networks, including via practice managers and senior practice partners. Incentivization was provided via a bespoke DCM fact sheet for those that completed the survey.

RESULTS

A total of 54 general practitioners representing all 4 UK nations responded to the survey. General practitioners most commonly self-assessed that they had "limited awareness" of DCM (n=24, 51%). General practitioners felt most commonly "moderately able" to recognize a case of DCM (n=21, 46%). In total, 13% (n=6) of respondents reported that they would not be at all able to recognize a patient with DCM. Respondents most commonly reported that they were "moderately confident" in their ability to triage a patient with DCM (n=19, 41%). A quarter of respondents reported no prior introduction to DCM throughout their medical training (n=13, 25%). The mean score for knowledge-based questions was 42.6% (SD 3.96%) with the lowest performance observed in patient demographic and clinical recognition items.

CONCLUSIONS

General practitioners lack confidence in the recognition and management of DCM. These findings are consistent with the diagnostic delays previously described in the literature at the primary care level. Further work to develop and implement educational interventions to general practitioner practices is a crucial step to improving patient outcomes in DCM.

A minimum data set-Core outcome set, core data elements, and core measurement set-For degenerative cervical myelopathy research (AO Spine RECODE DCM): A consensus study

BACKGROUND

Degenerative cervical myelopathy (DCM) is a progressive chronic spinal cord injury estimated to affect 1 in 50 adults. Without standardised guidance, clinical research studies have selected outcomes at their discretion, often underrepresenting the disease and limiting comparability between studies. Utilising a standard minimum data set formed via multi-stakeholder consensus can address these issues. This combines processes to define a core outcome set (COS)-a list of key outcomes-and core data elements (CDEs), a list of key sampling characteristics required to interpret the outcomes. Further "how" these outcomes should be measured and/or reported is then defined in a core measurement set (CMS). This can include a recommendation of a standardised time point at which outcome data should be reported. This study defines a COS, CDE, and CMS for DCM research.

METHODS AND FINDINGS

A minimum data set was developed using a series of modified Delphi processes. Phase 1 involved the setup of an international DCM stakeholder group. Phase 2 involved the development of a longlist of outcomes, data elements, and formation into domains. Phase 3 prioritised the outcomes and CDEs using a two-stage Delphi process. Phase 4 determined the final DCM minimal data set using a consensus meeting. Using the COS, Phase 5 finalised definitions of the measurement construct for each outcome. In Phase 6, a systematic review of the literature was performed, to scope and define the psychometric properties of measurement tools. Phase 7 used a modified Delphi process to inform the short-listing of candidate measurement tools. The final measurement set was then formed through a consensus meeting (Phase 8). To support implementation, the data set was then integrated into template clinical research forms (CRFs) for use in future clinical trials (Phase 9). In total, 28 outcomes and 6 domains (Pain, Neurological Function, Life Impact, Radiology, Economic Impact, and Adverse Events) were entered into the final COS. Thirty two outcomes and 4 domains (Individual, Disease, Investigation, and Intervention) were entered into the final CDE. Finally, 4 outcome instruments (mJOA, NDI, SF-36v2, and SAVES2) were identified for the CMS, with a recommendation for trials evaluating outcomes after surgery, to include baseline measurement and at 6 months from surgery.

CONCLUSIONS

The AO Spine RECODE-DCM has produced a minimum data set for use in DCM clinical trials today. These are available at https://myelopathy.org/minimum-dataset/. While it is anticipated the CDE and COS have strong and durable relevance, it is acknowledged that new measurement tools, alongside an increasing transition to study patients not undergoing surgery, may necessitate updates and adaptation, particularly with respect to the CMS.

Spinal cord motion and CSF flow in the cervical spine of 70 healthy participants

Pulsatile spinal cord and CSF velocities related to the cardiac cycle can be depicted by phase-contrast MRI. Among patients with spontaneous intracranial hypotension, we have recently described relevant differences compared with healthy controls in segment C2/C3. The method might be a promising tool to solve clinical and diagnostic ambiguities. Therefore, it is important to understand the physiological range and the effects of clinical and anatomical parameters in healthy volunteers. Within a prospective study, 3D T2-weighted MRI for spinal canal anatomy and cardiac-gated phase-contrast MRI adapted to CSF flow and spinal cord motion for time-resolved velocity data and derivatives were performed in 70 participants (age 20-79 years) in segments C2/C3 and C5/C6. Correlations were analyzed by multiple linear regression models; p < 0.01 was required to assume a significant impact of clinical or anatomical data quantified by the regression coefficient B. Data showed that in C2/C3, the CSF and spinal cord craniocaudal velocity ranges were 4.5 ± 0.9 and 0.55 ± 0.15 cm/s; the total displacements were 1.1 ± 0.3 and 0.07 ± 0.02 cm, respectively. The craniocaudal range of the CSF flow rate was 8.6 ± 2.4 mL/s; the CSF stroke volume was 2.1 ± 0.7 mL. In C5/C5, physiological narrowing of the spinal canal caused higher CSF velocity ranges and lower stroke volume (C5/C6 B = +1.64 cm/s, p < 0.001; B = -0.4 mL, p = 0.002, respectively). Aging correlated to lower spinal cord motion (e.g., B = -0.01 cm per 10 years of aging, p < 0.001). Increased diastolic blood pressure was associated with lower spinal cord motion and CSF flow parameters (e.g., C2/C3 CSF stroke volume B = -0.3 mL per 10 mmHg, p < 0.001). Males showed higher CSF flow and spinal cord motion (e.g., CSF stroke volume B = +0.5 mL, p < 0.001; total displacement spinal cord B = +0.016 cm, p = 0.002). We therefore propose to stratify data for age and sex and to adjust for diastolic blood pressure and segmental narrowing in future clinical studies.

Radiological Progression of Degenerative Cervical Myelopathy in a Clinically Stable Patient: Case Report

Degenerative cervical myelopathy (DCM) is a common neurological condition, with disease progression that is both variable and difficult to predict. Here, we present a case of DCM in a gentleman in his late 60s with significant radiological disease progression without consequent change in clinical symptoms. The case serves as a reminder of an enduring medical aphorism that clinical history and examination should be prioritized above more complex data, such as imaging investigations. In addition, the case also highlights that guidelines should be contextualized within individual clinical circumstances.

Degenerative Thoracic Myelopathy: A Scoping Review of Epidemiology, Genetics, and Pathogenesis

STUDY DESIGN

Literature Review.

OBJECTIVE

Myelopathy affecting the thoracic spinal cord can arise secondary to several aetiologies which have similar presentation and management. Consequently, there are many uncertainties in this area, including optimal terminology and definitions. Recent collaborative cervical spinal research has led to the proposal and subsequent community adoption of the name degenerative cervical myelopathy(DCM), which has facilitated the establishment of internationally-agreed research priorities for DCM. We put forward the case for the introduction of the term degenerative thoracic myelopathy(DTM) and degenerative spinal myelopathy(DSM) as an umbrella term for both DCM and DTM.

METHODS

Following PRISMA guidelines, a systematic literature search was performed to identify degenerative thoracic myelopathy literature in Embase and MEDLINE.

RESULTS

Conditions encompassed within DTM include thoracic spondylotic myelopathy, ossification of the posterior longitudinal ligament, ossification of the ligamentum flavum, calcification of ligaments, hypertrophy of ligaments, degenerative disc disease, thoracic osteoarthritis, intervertebral disc herniation, and posterior osteophytosis. The classic presentation includes girdle pain, gait disturbance, leg weakness, sensory disturbance, and bladder or bowel dysfunction, often with associated back pain. Surgical management is typically favoured with post-surgical outcomes dependent on many factors, including the causative pathology, and presence of additional stenosis.

CONCLUSION

The clinical entities encompassed by the term DTM are interrelated, can manifest concurrently, and present similarly. Building on the consensus adoption of DCM in the cervical spine and the recent proposal of degenerative cervical radiculopathy(DCR), extending this common nomenclature framework to the terms degenerative spinal myelopathy and degenerative thoracic myelopathy will help improve recognition and communication.

The Radiological Characteristics of Degenerative Cervical Kyphosis with Cervical Spondylotic Myelopathy

Introduction

In this study, we aim to describe the radiological characteristics of degenerative cervical kyphosis (DCK) with cervical spondylotic myelopathy (CSM) and discuss the relationship between DCK and the pathogenesis of spinal cord dysfunction.

Methods

In total, 90 patients with CSM hospitalized in our center from September 2017 to August 2022 were retrospectively examined in this study; they were then divided into the kyphosis group and the nonkyphosis group. The patients' demographics, clinical features, and radiological data were obtained, including gender, age, duration of illness, cervical Japanese Orthopaedic Association (JOA) score, cervical lordosis (CL), height of intervertebral space, degree of wedging vertebral body, degree of osteophyte formation, degree of disc herniation, degree of spinal cord compression, and anteroposterior diameter of the spinal cord. In the kyphosis group, kyphotic segments, apex of kyphosis, and segmental kyphosis angle were recorded. Radiological characteristics between the two groups were also compared. Correlation analysis was performed for different spinal cord compression types.

Results

As per our findings, the patients in the kyphosis group showed more remarkable wedging of the vertebral body, more severe anterior compression of the spinal cord, and a higher degree of disc herniation, while the posterior compression of the spinal cord was relatively mild when compared with the nonkyphosis group. CL was related to the type of spinal cord compression, as cervical kyphosis is an independent risk factor for anterior spinal cord compression.

Conclusions

DCK might play a vital role in the pathogenesis of spinal cord dysfunction. In patients with DCK, it was determined that the anterior column is less supported, and more severe anterior spinal cord compression is present. The anterior approach is supposed to be preferred for CSM patients with DCK.

Evidence-based commentary on the diagnosis, management, and further research of degenerative cervical spinal cord compression in the absence of clinical symptoms of myelopathy

Degenerative cervical myelopathy (DCM) represents the final consequence of a series of degenerative changes in the cervical spine, resulting in cervical spinal canal stenosis and mechanical stress on the cervical spinal cord. This process leads to subsequent pathophysiological processes in the spinal cord tissues. The primary mechanism of injury is degenerative compression of the cervical spinal cord, detectable by magnetic resonance imaging (MRI), serving as a hallmark for diagnosing DCM. However, the relative resilience of the cervical spinal cord to mechanical compression leads to clinical-radiological discordance, i.e., some individuals may exhibit MRI findings of DCC without the clinical signs and symptoms of myelopathy. This degenerative compression of the cervical spinal cord without clinical signs of myelopathy, potentially serving as a precursor to the development of DCM, remains a somewhat controversial topic. In this review article, we elaborate on and provide commentary on the terminology, epidemiology, natural course, diagnosis, predictive value, risks, and practical management of this condition-all of which are subjects of ongoing debate.

Cost-effectiveness of surgery for degenerative cervical myelopathy in the United Kingdom

PURPOSE

Degenerative cervical myelopathy (DCM) is the commonest cause of adult spinal cord dysfunction worldwide, for which surgery is the mainstay of treatment. At present, there is limited literature on the costs associated with the surgical management of DCM, and none from the United Kingdom (UK). This study aimed to evaluate the cost-effectiveness of DCM surgery within the National Health Service, UK.

MATERIALS AND METHODS

Incidence of DCM was identified from the Hospital Episode Statistics (HES) database for a single year using five ICD-10 diagnostic codes to represent DCM. Health Resource Group (HRG) data was used to estimate the mean incremental surgery (treatment) costs compared to non-surgical care, and the incremental effect (quality adjusted life year (QALY) gain) was based on data from a previous study. A cost per QALY value of <£30,000/QALY (GBP) was considered acceptable and cost-effective, as per the National Institute for Health and Clinical Excellence (NICE) guidance. A sensitivity analysis was undertaken (±5%, ±10% and ±20%) to account for variance in both the cost of admission and QALY gain.

RESULTS

The total number of admissions for DCM in 2018 was 4,218. Mean age was 62 years, with 54% of admissions being of working age (18-65 years). The overall estimated cost of admissions for DCM was £38,871,534 for the year. The mean incremental (per patient) cost of surgical management of DCM was estimated to be £9,216 (ranged £2,358 to £9,304), with a QALY gain of 0.64, giving an estimated cost per QALY value of £14,399/QALY. Varying the QALY gain by ±20%, resulted in cost/QALY figures between £12,000 (+20%) and £17,999 (-20%).

CONCLUSIONS

Surgery is estimated to be a cost-effective treatment of DCM amongst the UK population.

The Prevalence of Asymptomatic Cervical Spinal Cord Compression in Individuals Presenting With Symptomatic Lumbar Spinal Stenosis: A Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

The aim of this study was to determine the prevalence of asymptomatic cervical spinal cord compression (CSCC) in individuals with lumbar spinal stenosis (LSS).

METHODS

A systematic electronic search was conducted in Medline, EMBASE, Scopus, and Web of Science without language restriction, with no starting date limit to June 8, 2023, to define the prevalence of asymptomatic CSCC in symptomatic LSS patients. Asymptomatic CSCC was defined based on radiographic studies. All types of studies were included in the review. Meta-analysis was performed on the reported prevalence of asymptomatic CSCC in LSS.

RESULTS

The database search yielded 10,272 articles. After a full-text review, five studies were included in the final review, comprising a total of 1043 cases. Two studies had a low risk for bias, two moderate, and one estimated to be high risk. The range of prevalence of asymptomatic CSCC in LSS in the five included studies was between 24% and 61%. Meta-analysis on the reported prevalence of asymptomatic CSCC patients with symptomatic LSS demonstrated that the random pooled prevalence was 35% (95% CI: 23 to 48).

CONCLUSIONS

Asymptomatic CSCC appears to occur in a high number of patients, with this study noting its presence in one-third of patients with LSS. Based on these findings, we strongly recommend that spine surgeons exercise particular caution during the positioning of patients who are undergoing surgery for lumbar stenosis. Furthermore, it is imperative to monitor individuals with symptomatic LSS closely for any potential signs of emerging myelopathy.

Finite Element Analysis for Degenerative Cervical Myelopathy: Scoping Review of the Current Findings and Design Approaches, Including Recommendations on the Choice of Material Properties

BACKGROUND

Degenerative cervical myelopathy (DCM) is a slow-motion spinal cord injury caused via chronic mechanical loading by spinal degenerative changes. A range of different degenerative changes can occur. Finite element analysis (FEA) can predict the distribution of mechanical stress and strain on the spinal cord to help understand the implications of any mechanical loading. One of the critical assumptions for FEA is the behavior of each anatomical element under loading (ie, its material properties).

OBJECTIVE

This scoping review aims to undertake a structured process to select the most appropriate material properties for use in DCM FEA. In doing so, it also provides an overview of existing modeling approaches in spinal cord disease and clinical insights into DCM.

METHODS

We conducted a scoping review using qualitative synthesis. Observational studies that discussed the use of FEA models involving the spinal cord in either health or disease (including DCM) were eligible for inclusion in the review. We followed the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines. The MEDLINE and Embase databases were searched to September 1, 2021. This was supplemented with citation searching to retrieve the literature used to define material properties. Duplicate title and abstract screening and data extraction were performed. The quality of evidence was appraised using the quality assessment tool we developed, adapted from the Newcastle-Ottawa Scale, and shortlisted with respect to DCM material properties, with a final recommendation provided. A qualitative synthesis of the literature is presented according to the Synthesis Without Meta-Analysis reporting guidelines.

RESULTS

A total of 60 papers were included: 41 (68%) "FEA articles" and 19 (32%) "source articles." Most FEA articles (33/41, 80%) modeled the gray matter and white matter separately, with models typically based on tabulated data or, less frequently, a hyperelastic Ogden variant or linear elastic function. Of the 19 source articles, 14 (74%) were identified as describing the material properties of the spinal cord, of which 3 (21%) were considered most relevant to DCM. Of the 41 FEA articles, 15 (37%) focused on DCM, of which 9 (60%) focused on ossification of the posterior longitudinal ligament. Our aggregated results of DCM FEA indicate that spinal cord loading is influenced by the pattern of degenerative changes, with decompression alone (eg, laminectomy) sufficient to address this as opposed to decompression combined with other procedures (eg, laminectomy and fusion).

CONCLUSIONS

FEA is a promising technique for exploring the pathobiology of DCM and informing clinical care. This review describes a structured approach to help future investigators deploy FEA for DCM. However, there are limitations to these recommendations and wider uncertainties. It is likely that these will need to be overcome to support the clinical translation of FEA to DCM.

The significance of metabolic disease in degenerative cervical myelopathy: a systematic review

Introduction

Degenerative cervical myelopathy (DCM) is a form of chronic spinal cord injury, with a natural history of potential for progression over time. Whilst driven by mechanical stress on the spinal cord from degenerative and congenital pathology, the neurological phenotype of DCM is likely to be modified by multiple systemic factors. The role of metabolic factors is therefore of interest, particularly given that ischaemia is considered a key pathological mechanism of spinal cord injury. The objective was therefore to synthesise current evidence on the effect of metabolism on DCM susceptibility, severity, and surgical outcomes.

Methods

A systematic review in MEDLINE and Embase was conducted following PRISMA guidelines. Full-text papers in English, with a focus on DCM and metabolism, including diabetes, cardiovascular disease, anaemia, and lipid profile, were eligible for inclusion. Risk of methodological bias was assessed using the Joanna Briggs Institute (JBI) critical assessment tools. Quality assessments were performed using the GRADE assessment tool. Patient demographics, metabolic factors and the relationships between metabolism and spinal cord disease, spinal column disease and post-operative outcomes were assessed.

Results

In total, 8,523 papers were identified, of which 57 met criteria for inclusion in the final analysis. A total of 91% (52/57) of included papers assessed the effects of diabetes in relation to DCM, of which 85% (44/52) reported an association with poor surgical outcomes; 42% of papers (24/57) discussed the association between cardiovascular health and DCM, of which 88% (21/24) reported a significant association. Overall, DCM patients with diabetes or cardiovascular disease experienced greater perioperative morbidity and poorer neurological recovery. They were also more likely to have comorbidities such as obesity and hyperlipidaemia.

Conclusion

Metabolic factors appear to be associated with surgical outcomes in DCM. However, evidence for a more specific role in DCM susceptibility and severity is uncertain. The pathophysiology and natural history of DCM are critical research priorities; the role of metabolism is therefore a key area for future research focus.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021268814.

Respiratory dysfunction in degenerative cervical myelopathy: A systematic review

INTRODUCTION

Degenerative cervical myelopathy is a condition of symptomatic cervical spinal cord compression secondary to a range of degenerative spinal pathology. Respiratory symptoms such as shortness of breath are not uncommonly reported by people with DCM and respiratory dysfunction has been described in several DCM studies. The objective of this review was therefore to systematically synthesise the current evidence on the relationship between DCM and respiratory function.

METHODS

The review was registered on PROSPERO and adhered to PRISMA guidelines. Ovid MEDLINE and Embase were searched from inception to 14th March 2023. DCM studies reporting on any measure or outcome relating to respiratory function or disease were eligible. Reference lists of included studies and relevant reviews articles were hand searched. Title, abstract and full text screening, risk of bias and GRADE assessments were completed in duplicate. A quantitative synthesis is presented.

RESULTS

Of 1991 studies identified by literature searching, 13 met inclusion criteria: 3 cohort studies, 5 case-control studies, 1 case series and 4 case studies. Forced vital capacity (FVC), peak expiratory flow rate (PEFR) and maximal voluntary ventilation (MVV) were reported to be lower in DCM patients than controls; there was inconsistency in comparisons of forced expiratory volume in 1 s (FEV1). There was conflicting evidence on whether surgical decompression was associated with improvements in respiratory parameters and on the relationship between level of spinal cord compression and respiratory dysfunction.

CONCLUSION

DCM may be associated with respiratory dysfunction. However, consistency and quality of evidence is currently low. Further work should characterise respiratory dysfunction in DCM patients more rigorously and investigate putative mechanisms such as disruption to cervical nerve roots responsible for diaphragmatic innervation and damage to descending spinal projections from brainstem respiratory centres.

Machine Learning and Symptom Patterns in Degenerative Cervical Myelopathy: Web-Based Survey Study

BACKGROUND

Degenerative cervical myelopathy (DCM), a progressive spinal cord injury caused by spinal cord compression from degenerative pathology, often presents with neck pain, sensorimotor dysfunction in the upper or lower limbs, gait disturbance, and bladder or bowel dysfunction. Its symptomatology is very heterogeneous, making early detection as well as the measurement or understanding of the underlying factors and their consequences challenging. Increasingly, evidence suggests that DCM may consist of subgroups of the disease, which are yet to be defined.

OBJECTIVE

This study aimed to explore whether machine learning can identify clinically meaningful groups of patients based solely on clinical features.

METHODS

A survey was conducted wherein participants were asked to specify the clinical features they had experienced, their principal presenting complaint, and time to diagnosis as well as demographic information, including disease severity, age, and sex. K-means clustering was used to divide respondents into clusters according to their clinical features using the Euclidean distance measure and the Hartigan-Wong algorithm. The clinical significance of groups was subsequently explored by comparing their time to presentation, time with disease severity, and other demographics.

RESULTS

After a review of both ancillary and cluster data, it was determined by consensus that the optimal number of DCM response groups was 3. In Cluster 1, there were 40 respondents, and the ratio of male to female participants was 13:21. In Cluster 2, there were 92 respondents, with a male to female participant ratio of 27:65. Cluster 3 had 57 respondents, with a male to female participant ratio of 9:48. A total of 6 people did not report biological sex in Cluster 1. The mean age in this Cluster was 56.2 (SD 10.5) years; in Cluster 2, it was 54.7 (SD 9.63) years; and in Cluster 3, it was 51.8 (SD 8.4) years. Patients across clusters significantly differed in the total number of clinical features reported, with more clinical features in Cluster 3 and the least clinical features in Cluster 1 (Kruskal-Wallis rank sum test: χ22=159.46; P<.001). There was no relationship between the pattern of clinical features and severity. There were also no differences between clusters regarding time since diagnosis and time with DCM.

CONCLUSIONS

Using machine learning and patient-reported experience, 3 groups of patients with DCM were defined, which were different in the number of clinical features but not in the severity of DCM or time with DCM. Although a clearer biological basis for the clusters may have been missed, the findings are consistent with the emerging observation that DCM is a heterogeneous disease, difficult to diagnose or stratify. There is a place for machine learning methods to efficiently assist with pattern recognition. However, the challenge lies in creating quality data sets necessary to derive benefit from such approaches.

Impaired communication at the neuromotor axis during Degenerative Cervical Myelopathy

Degenerative Cervical Myelopathy (DCM) is a progressive neurological condition characterized by structural alterations in the cervical spine, resulting in compression of the spinal cord. While clinical manifestations of DCM are well-documented, numerous unanswered questions persist at the molecular and cellular levels. In this study, we sought to investigate the neuromotor axis during DCM. We use a clinically relevant mouse model, where after 3 months of DCM induction, the sensorimotor tests revealed a significant reduction in both locomotor activity and muscle strength compared to the control group. Immunohistochemical analyses showed alterations in the gross anatomy of the cervical spinal cord segment after DCM. These changes were concomitant with the loss of motoneurons and a decrease in the number of excitatory synaptic inputs within the spinal cord. Additionally, the DCM group exhibited a reduction in the endplate surface, which correlated with diminished presynaptic axon endings in the supraspinous muscles. Furthermore, the biceps brachii (BB) muscle exhibited signs of atrophy and impaired regenerative capacity, which inversely correlated with the transversal area of remnants of muscle fibers. Additionally, metabolic assessments in BB muscle indicated an increased proportion of oxidative skeletal muscle fibers. In line with the link between neuromotor disorders and gut alterations, DCM mice displayed smaller mucin granules in the mucosa layer without damage to the epithelial barrier in the colon. Notably, a shift in the abundance of microbiota phylum profiles reveals an elevated Firmicutes-to-Bacteroidetes ratio-a consistent hallmark of dysbiosis that correlates with alterations in gut microbiota-derived metabolites. Additionally, treatment with short-chain fatty acids stimulated the differentiation of the motoneuron-like NSC34 cell line. These findings shed light on the multifaceted nature of DCM, resembling a synaptopathy that disrupts cellular communication within the neuromotor axis while concurrently exerting influence on other systems. Notably, the colon emerges as a focal point, experiencing substantial perturbations in both mucosal barrier integrity and the delicate balance of intestinal microbiota.

Brain MRI changes in degenerative cervical myelopathy: a systematic review

BACKGROUND

Degenerative cervical myelopathy (DCM) is the most common cause of adult spinal cord dysfunction globally. Associated neurological symptoms and signs have historically been explained by pathobiology within the cervical spine. However, recent advances in imaging have shed light on numerous brain changes in patients with DCM, and it is hypothesised that these changes contribute to DCM pathogenesis. The aetiology, significance, and distribution of these supraspinal changes is currently unknown. The objective was therefore to synthesise all current evidence on brain changes in DCM.

METHODS

A systematic review was performed. Cross-sectional and longitudinal studies with magnetic resonance imaging on a cohort of patients with DCM were eligible. PRISMA guidelines were followed. MEDLINE and Embase were searched to 28th August 2023. Duplicate title/abstract screening, data extraction and risk of bias assessments were conducted. A qualitative synthesis of the literature is presented as per the Synthesis Without Meta-Analysis (SWiM) reporting guideline. The review was registered with PROSPERO (ID: CRD42022298538).

FINDINGS

Of the 2014 studies that were screened, 47 studies were identified that used MRI to investigate brain changes in DCM. In total, 1500 patients with DCM were included in the synthesis, with a mean age of 53 years. Brain alterations on MRI were associated with DCM both before and after surgery, particularly within the sensorimotor network, visual network, default mode network, thalamus and cerebellum. Associations were commonly reported between brain MRI alterations and clinical measures, particularly the Japanese orthopaedic association (JOA) score. Risk of bias of included studies was low to moderate.

INTERPRETATION

The rapidly expanding literature provides mounting evidence for brain changes in DCM. We have identified key structures and pathways that are altered, although there remains uncertainty regarding the directionality and clinical significance of these changes. Future studies with greater sample sizes, more detailed phenotyping and longer follow-up are now needed.

FUNDING

ODM is supported by an Academic Clinical Fellowship at the University of Cambridge. BMD is supported by an NIHR Clinical Doctoral Fellowship at the University of Cambridge (NIHR300696). VFJN is supported by an NIHR Rosetrees Trust Advanced Fellowship (NIHR302544). This project was supported by an award from the Rosetrees Foundation with the Storygate Trust (A2844).

Is the type and/or co-existence of degenerative spinal pathology associated with the occurrence of degenerative cervical myelopathy? A single centre retrospective analysis of individuals with MRI defined cervical cord compression

BACKGROUND

Degenerative cervical myelopathy (DCM) arises from spinal degenerative changes injuring the cervical spinal cord. Most cord compression is incidental, referred to as asymptomatic spinal cord compression (ASCC). How and why ASCC differs from DCM is poorly understood. In this paper, we study a local cohort to identify specific types and groups of degenerative pathology more likely associated with DCM than ASCC.

METHODS

This study was a retrospective cohort analysis (IRB Approval ID: PRN10455). The frequency of degenerative findings between those with ASCC and DCM patients were compared using network analysis, hierarchical clustering, and comparison to existing literature to identify potential subgroups in a local cohort (N = 155) with MRI-defined cervical spinal cord compression. Quantitative measures of spinal cord compression (MSCC and MCC) were used to confirm their relevance.

RESULTS

ELF (8.7 %, 95 % CI 3.8-13.6 % vs 35.7 %, 95 % CI 27.4-44.0 %) Congenital Stenosis (3.9 %, 95 % CI 0.6-7.3 % vs 25.0 %, 95 % CI 17.5-32.5 %), and OPLL (0.0 %, 95 % CI 0.0-0.0 % vs 3.6 %, 95 % CI 0.3-6.8 %) were more likely in patients with DCM. Comparative network analysis indicated loss of lordosis was associated with ASCC, whilst ELF with DCM. Hierarchical Cluster Analysis indicated four sub-groups: multi-level disc disease with ELF, single-level disc disease without loss of lordosis and OPLL with DCM, and single-level disc disease with loss of lordosis with ASCC. Quantitative measures of cord compression were higher in groups associated with DCM, but similar in patients with single-level disc disease and loss of lordosis.

CONCLUSIONS

This study identified four subgroups based on degenerative pathology requiring further investigation.

Toward Shared Decision-Making in Degenerative Cervical Myelopathy: Protocol for a Mixed Methods Study

BACKGROUND

Health care decisions are a critical determinant in the evolution of chronic illness. In shared decision-making (SDM), patients and clinicians work collaboratively to reach evidence-based health decisions that align with individual circumstances, values, and preferences. This personalized approach to clinical care likely has substantial benefits in the oversight of degenerative cervical myelopathy (DCM), a type of nontraumatic spinal cord injury. Its chronicity, heterogeneous clinical presentation, complex management, and variable disease course engenders an imperative for a patient-centric approach that accounts for each patient's unique needs and priorities. Inadequate patient knowledge about the condition and an incomplete understanding of the critical decision points that arise during the course of care currently hinder the fruitful participation of health care providers and patients in SDM. This study protocol presents the rationale for deploying SDM for DCM and delineates the groundwork required to achieve this.

OBJECTIVE

The study's primary outcome is the development of a comprehensive checklist to be implemented upon diagnosis that provides patients with essential information necessary to support their informed decision-making. This is known as a core information set (CIS). The secondary outcome is the creation of a detailed process map that provides a diagrammatic representation of the global care workflows and cognitive processes involved in DCM care. Characterizing the critical decision points along a patient's journey will allow for an effective exploration of SDM tools for routine clinical practice to enhance patient-centered care and improve clinical outcomes.

METHODS

Both CISs and process maps are coproduced iteratively through a collaborative process involving the input and consensus of key stakeholders. This will be facilitated by Myelopathy.org, a global DCM charity, through its Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy community. To develop the CIS, a 3-round, web-based Delphi process will be used, starting with a baseline list of information items derived from a recent scoping review of educational materials in DCM, patient interviews, and a qualitative survey of professionals. A priori criteria for achieving consensus are specified. The process map will be developed iteratively using semistructured interviews with patients and professionals and validated by key stakeholders.

RESULTS

Recruitment for the Delphi consensus study began in April 2023. The pilot-testing of process map interview participants started simultaneously, with the formulation of an initial baseline map underway.

CONCLUSIONS

This protocol marks the first attempt to provide a starting point for investigating SDM in DCM. The primary work centers on developing an educational tool for use in diagnosis to enable enhanced onward decision-making. The wider objective is to aid stakeholders in developing SDM tools by identifying critical decision junctures in DCM care. Through these approaches, we aim to provide an exhaustive launchpad for formulating SDM tools in the wider DCM community.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/46809.

Factors Influencing Surgical Decision-Making in the Posterior Laminectomy With Fixation for Degenerative Cervical Myelopathy (POLYFIX-DCM) Trial: Survey Study

BACKGROUND

Degenerative cervical myelopathy (DCM) is estimated to affect 2% of the adult population. DCM occurs when degenerative processes cause compression and injure the spinal cord. Surgery to remove the stress caused by the compression of the spinal cord is the mainstay of treatment, with a range of techniques in use. Although various factors are described to inform the selection of these techniques, there needs to be more consensus and limited comparative evidence.

OBJECTIVE

The main objective of this survey was to explore the variation of practice and decision-making, with a focus on laminectomy versus laminectomy and fusion in posterior surgery of the cervical spine. We present the results of a survey conducted among the principal investigators (PIs) of the National Institute for Health and Care Research (NIHR) randomized controlled trial on posterior laminectomy with fixation for degenerative cervical myelopathy (POLYFIX-DCM).

METHODS

A series of 7 cases were shared with 24 PIs using SurveyMonkey. Each case consisted of a midsagittal T2-weighted magnetic resonance imaging and lateral cervical x-rays in flexion and extension. Surgeons were asked if their preferred approach was anterior or posterior. If posterior, they were asked whether they preferred to instrument and whether they had the equipoise to randomize in the NIHR POLYFIX-DCM trial. Variability in decision-making was then explored using factors reported to inform decision-making, such as alignment, location of compression, number of levels operated, presence of mobile spondylolisthesis, and patient age.

RESULTS

The majority of PIs (16/30, 53%) completed the survey. Overall, PIs favored a posterior approach (12/16, 75%) with instrumentation (75/112, average 66%) and would randomize (67/112, average 62%) most cases. Factors reported to inform decision-making poorly explained variability in responses in both univariate testing and with a multivariate model (R2=0.1). Only surgeon experience of more than 5 years and orthopedic specialty training background were significant predictors, both associated with an anterior approach (odds ratio [OR] 1.255; P=.02 and OR 1.344; P=.007, respectively) and fusion for posterior procedures (OR 0.628; P<.001 and OR 1.344; P<.001, respectively). Surgeon experience also significantly affected the openness to randomize, with those with more than 5 years of experience less likely to randomize (OR -0.68; P<.001).

CONCLUSIONS

In this representative sample of spine surgeons participating in the POLYFIX-DCM trial as investigators, there is no consensus on surgical strategy, including the role of instrumented fusion following posterior decompression. Overall, this study supports the view that there appears to be a clinical equipoise, and conceptually, a randomized controlled trial appears feasible, which sets the scene for the NIHR POLYFIX-DCM trial.

Rapidly Deteriorating Degenerative Cervical Myelopathy Following Ventricular Shunt Revision for Hydrocephalus: Case Report

A female patient in her early 40s presented with a several-month history of gait unsteadiness and dragging her left leg. She had a background of congenital hydrocephalus, treated with a ventriculoatrial shunt. On examination, she had increased tone and brisk reflexes in the lower limbs and a positive Hoffmann sign. A computed tomography (CT) scan and shunt series x-rays identified hydrocephalus secondary to a disconnected shunt. Magnetic resonance imaging (MRI) of her cervical spine was also performed as part of the workup for her presenting symptoms and demonstrated features compatible with degenerative cervical myelopathy (DCM). The patient subsequently underwent a shunt revision. Following the operation, her walking and hand function deteriorated over a period of several weeks. She consequently underwent an anterior cervical decompression and fusion for DCM, which partially improved her symptoms. The sequence of events suggests that the shunt surgery may have precipitated a worsening of the DCM. Possible explanations include spinal cord injury related to neck extension or hypoperfusion during intubation and general anesthesia or the loss of cerebrospinal fluid cushioning following the reinstitution of effective cerebrospinal fluid shunting. Surgeons should be alert to this possibility and offer prompt surgical intervention for DCM if required.

Classification of cervical disc herniation myelopathy or radiculopathy: a magnetic resonance imaging-based analysis

Background

Preoperative magnetic resonance imaging (MRI) can clearly show the location and level of disc herniation. When the symptoms are consistent with the Prominent segments, surgical treatment can be indicated. However, the varied extents of the protruding masses in cervical disc herniation (CDH) have been rarely reported. This study aimed to characterize the severity of CDH and to develop a reproducible grading and zoning system for cervical disc degeneration.

Methods

A total of 200 patients who presented with single CDH and underwent MRI/computed tomography (CT) scans were enrolled in this prospective study between 2018 and 2021. A total of 170 cervical discs were graded according to MRI by 3 spine surgeons in a blinded fashion. CDHs were graded 1-3, with regions A-C. All patients with grade 1 and mild C symptoms were excluded. The foramen facet spinal (FFS) classification based on MRI Japanese Orthopedic Association (JOA) scores and the incidence of complications were evaluated and analyzed, and follow-up outcomes were assessed.

Results

Areas 2-A, 2-B, and 1-C had high motor function scores, areas 2-A, 3-A, and 2-AB had high sensory scores, but areas 3-AB and 3-A had low bladder function scores. Areas 3-AB had the most severe symptoms and the lowest scores. Area 1-C showed neurogenic abnormal sensation and higher visual analog scale (VAS) scores. A good/excellent outcome as indicated by the JOA score was 94.70% at 3 months and 92.35% at 1 year in 170 patients. The complication rate was 9.41%. The diagnostic coefficient of the FFS classification was 0.888, P<0.001.

Conclusions

The FFS classification is an objective scoring system that can be applied similarly by multiple examiners and is correlated with clinical symptoms.

Difference between Anterior and Posterior Cord Compression and Its Clinical Implication in Patients with Degenerative Cervical Myelopathy

In degenerative cervical myelopathy (DCM), the low anteroposterior compression ratio of the spinal cord is known to be associated with a neurologic deficit. However, there is little detailed analysis of spinal cord compression. Axial magnetic resonance images of 183 DCM patients at normal C2-C3 and maximal cord compression segments were analyzed. The anterior (A), posterior (P), and anteroposterior length and width (W) of the spinal cord were measured. Correlation analyses between radiographic parameters and each section of Japanese Orthopedic Association (JOA) scores and comparisons of the patients divided by A (below or above 0, 1, or 2 mm) were performed. Between C2-C3 and maximal compression segments, the mean differences of A and P were 2.0 (1.2) and 0.2 (0.8) mm. The mean anteroposterior compression ratios were 0.58 (0.13) at C2-C3 and 0.32 (0.17) at maximal compression. The A and A/W ratio were significantly correlated with four sections and the total JOA scores (p < 0.05), but the P and P/W ratio did not demonstrate any correlations. Patients with A < 1 mm had significantly lower JOA scores than those with A ≥ 1 mm. In patients with DCM, spinal cord compression occurs mainly in the anterior part and the anterior cord length of <1 mm is particularly associated with neurologic deficits.

Degenerative cervical myelopathy: Where have we been? Where are we now? Where are we going?

Degenerative cervical myelopathy (DCM), a recently coined term, encompasses a group of age-related and genetically associated pathologies that affect the cervical spine, including cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament (OPLL). Given the significant contribution of DCM to global disease and disability, there are worldwide efforts to promote research and innovation in this area. An AO Spine effort termed 'RECODE-DCM' was initiated to create an international multistakeholder consensus group, involving patients, caregivers, physicians and researchers, to focus on launching actionable discourse on DCM. In order to improve the management, treatment and results for DCM, the RECODE-DCM consensus group recently identified ten priority areas for translational research. The current article summarizes recent advancements in the field of DCM. We first discuss the comprehensive definition recently refined by the RECODE-DCM group, including steps taken to arrive at this definition and the supporting rationale. We then provide an overview of the recent advancements in our understanding of the pathophysiology of DCM and modalities to clinically assess and diagnose DCM. A focus will be set on advanced imaging techniques that may offer the opportunity to improve characterization and diagnosis of DCM. A summary of treatment modalities, including surgical and nonoperative options, is then provided along with future neuroprotective and neuroregenerative strategies. This review concludes with final remarks pertaining to the genetics involved in DCM and the opportunity to leverage this knowledge toward a personalized medicine approach.

Human spinal cord tissue is an underutilised resource in degenerative cervical myelopathy: findings from a systematic review of human autopsies

STUDY DESIGN

Systematic review.

BACKGROUND

Although degenerative cervical myelopathy (DCM) is the most prevalent spinal cord condition worldwide, the pathophysiology remains poorly understood. Our objective was to evaluate existing histological findings of DCM on cadaveric human spinal cord tissue and explore their consistency with animal models.

METHODS

MEDLINE and Embase were systematically searched (CRD42021281462) for primary research reporting on histological findings of DCM in human cadaveric spinal cord tissue. Data was extracted using a piloted proforma. Risk of bias was assessed using Joanna Briggs Institute critical appraisal tools. Findings were compared to a systematic review of animal models (Ahkter et al. 2020 Front Neurosci 14).

RESULTS

The search yielded 4127 unique records. After abstract and full-text screening, 19 were included in the final analysis, reporting on 150 autopsies (71% male) with an average age at death of 67.3 years. All findings were based on haematoxylin and eosin (H&E) staining. The most commonly reported grey matter findings included neuronal loss and cavity formation. The most commonly reported white matter finding was demyelination. Axon loss, gliosis, necrosis and Schwann cell proliferation were also reported. Findings were consistent amongst cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament. Cavitation was notably more prevalent in human autopsies compared to animal models.

CONCLUSION

Few human spinal cord tissue studies have been performed. Neuronal loss, demyelination and cavitation were common findings. Investigating the biological basis of DCM is a critical research priority. Human spinal cord specimen may be an underutilised but complimentary approach.

Lived experience-centred word clouds may improve research uncertainty gathering in priority setting partnerships

INTRODUCTION

AO Spine RECODE-DCM was a multi-stakeholder priority setting partnership (PSP) to define the top ten research priorities for degenerative cervical myelopathy (DCM). Priorities were generated and iteratively refined using a series of surveys administered to surgeons, other healthcare professionals (oHCP) and people with DCM (PwDCM). The aim of this work was to utilise word clouds to enable the perspectives of people with the condition to be heard earlier in the PSP process than is traditionally the case. The objective was to evaluate the added value of word clouds in the process of defining research uncertainties in National Institute for Health Research (NIHR) James Lind Alliance (JLA) Priority Setting Partnerships.

METHODS

Patient-generated word clouds were created for the four survey subsections of the AO Spine RECODE-DCM PSP: diagnosis, treatment, long-term management and other issues. These were then evaluated as a nested methodological study. Word-clouds were created and iteratively refined by an online support group of people with DCM, before being curated by the RECODE-DCM management committee and expert healthcare professional representatives. The final word clouds were embedded within the surveys administered at random to 50% of participants. DCM research uncertainties suggested by participants were compared pre- and post-word cloud presentation.

RESULTS

A total of 215 (50.9%) participants were randomised to the word cloud stream, including 118 (55%) spinal surgeons, 52 (24%) PwDCM and 45 (21%) oHCP. Participants submitted 434 additional uncertainties after word cloud review: word count was lower and more uniform across each survey subsections compared to pre-word cloud uncertainties. Twenty-three (32%) of the final 74 PSP summary questions did not have a post-word cloud contribution and no summary question was formed exclusively on post-word cloud uncertainties. There were differences in mapping of pre- and post-word cloud uncertainties to summary questions, with greater mapping of post-word cloud uncertainties to the number 1 research question priority: raising awareness. Five of the final summary questions were more likely to map to the research uncertainties suggested by participants after having reviewed the word clouds.

CONCLUSIONS

Word clouds may increase the perspective of underrepresented stakeholders in the research question gathering stage of priority setting partnerships. This may help steer the process towards research questions that are of highest priority for people with the condition.

Could spinal cord oscillation contribute to spinal cord injury in degenerative cervical myelopathy?

Introduction

Degenerative Cervical Myelopathy [DCM] is a slow-motion spinal cord injury. Compression and dynamic compression have been considered disease hallmarks. However, this is likely an oversimplification, as compression is more commonly incidental and has only modest correlation to disease severity. MRI studies have recently suggested spinal cord oscillation could play a role.

Research question

To determine if spinal cord oscillation could contribute to spinal cord injury in degenerative cervical myelopathy.

Material and methods

A computational model of an oscillating spinal cord was developed from imaging of a healthy volunteer. Using finite element analysis, the observed implications of stress and strain, were measured in the context of a simulated disc herniation. The significance was bench marked by comparison to a more recognised dynamic injury mechanism; a flexion extension model of dynamic compression.

Results

Spinal cord oscillation altered both compressive and shear strain on the spinal cord. Following initial compression, compressive strain moves from within the spinal cord to the spinal cord surface, whilst shear strain is magnified by 0.1-0.2, depending on the amplitude of oscillation. These orders of magnitude are equivalent to a dynamic compression model.

Discussion and conclusion

Spinal cord oscillation could significantly contribute to spinal cord damage across DCM. Its repeated occurrence with every heartbeat, draws parallels to the concept of fatigue damage, which could reconcile differing theories on the origins of DCM. This remains hypothetical at this stage, and further investigations are required.

Life expectancy in patients with degenerative cervical myelopathy is currently reduced but can be restored with timely treatment

PURPOSE

Degenerative cervical myelopathy is a progressive slow-motion spinal cord injury. Surgery is the mainstay of treatment. Baseline disability predicts surgical recovery; therefore, timely treatment is critical to restoring function. However, current challenges mean most patients present with advanced disease and are instead left with life changing disabilities. While short-term mortality is rarely reported, the long-term effects of this on life expectancy are unknown, including whether function could be modifiable with timely treatment. This article investigates the effect of DCM on life expectancy.

METHODS

The survival of patients from an observational study of patients undergoing surgery from 1994 to 2007 was compared to their expected survival using a gender- and aged -matched cohort. Comparisons were made by one sample log-rank test and standardised mortality ratios. Factors associated with survival were explored using a Cox regression analysis, including disease severity.

RESULTS

A total of 357 patients were included in the analysis. After a median follow-up of 15.3 years, 135 of 349 patients had died; 114.7 deaths would have been expected. The DCM cohort had an increased risk of death compared to the non-DCM cohort (standardised mortality ratio 1.18 [95% CI: 1.02-1.34]. Age at operation 1.08 (95% CI: 1.07 to 1.1, p < 0.001) and severe DCM 1.6 (95% CI: 1.06 to 2.3, p = 0.02) were associated with worse survival (N = 287). In those surviving at least 2 years after surgery, only severe DCM was associated with conditional survival (HR 1.6, 95% CI 1.04 2.4, p = 0.03).

CONCLUSION

Life expectancy is reduced in those undergoing surgery for DCM. This is driven by premature mortality among those left with severe disability. As disability can be reduced with timely treatment, these findings reinforce the need for collective and global action to raise awareness of DCM and enable early diagnosis.

Prognostic and risk factors for the surgical efficacy of central spinal cord syndrome in patients with preexisting degenerative cervical spinal cord compression

OBJECTIVES

To analyze the prognostic and risk factors related to surgical treatment of central spinal cord syndrome (CSS) and to find out the optimal timing of operative management.

METHODS

From January 2011 to January 2019, a consecutive series of 128 patients with CSS confirmed by magnetic resonance imaging (MRI) were retrospectively analyzed including their clinical records and radiologic data from a prospectively maintained database in a single center.

RESULTS

According to the prognosis evaluated by the modified Japanese Orthopedic Association (mJOA), American Spinal Injury Association (ASIA) motor score (AMS), and ASIA impairment scale (AIS) grade, the overall postoperative outcome was good. Finally, it was found that surgical timing, presence of myelopathy or not at baseline, AMS at admission, and compression ratio were independent factors affecting the prognosis. Surgery as soon as possible after the occurrence of CSS is still advocated.

CONCLUSION

Cervical myelopathy at baseline, compression ratio, and AMS score on admission were independent prognostic factors for the surgical treatment of CSS. If surgical indications are clear, early surgical intervention should be actively considered.

Structural Relationship between Cerebral Gray and White Matter Alterations in Degenerative Cervical Myelopathy

Patients with degenerative cervical myelopathy (DCM) undergo adaptive supraspinal changes. However, it remains unknown how subcortical white matter changes reflect the gray matter loss. The current study investigated the interrelationship between gray matter and subcortical white matter alterations in DCM patients. Cortical thickness of gray matter, as well as the intra-cellular volume fraction (ICVF) of subcortical whiter matter, were assessed in a cohort of 44 patients and 17 healthy controls (HCs). The results demonstrated that cortical thinning of sensorimotor and pain related regions is associated with more severe DCM symptoms. ICVF values of subcortical white matter underlying the identified regions were significantly lower in study patients than in HCs. The left precentral gyrus (r = 0.5715, p < 0.0001), the left supramarginal gyrus (r = 0.3847, p = 0.0099), the left postcentral gyrus (r = 0.5195, p = 0.0003), the right superior frontal gyrus (r = 0.3266, p = 0.0305), and the right caudal (r = 0.4749, p = 0.0011) and rostral anterior cingulate (r = 0.3927, p = 0.0084) demonstrated positive correlations between ICVF and cortical thickness in study patients, but no significant correlations between ICVF and cortical thickness were observed in HCs. Results from the current study suggest that DCM may cause widespread gray matter alterations and underlying subcortical neurite loss, which may serve as potential imaging biomarkers reflecting the pathology of DCM.

Degenerative cervical myelopathy education in UK medical schools: a national cross-sectional survey of medical students

INTRODUCTION

Degenerative cervical myelopathy (DCM) is a common and progressive neurological condition caused by injury of the cervical spinal cord by degenerative spinal pathology. Delayed diagnosis leading to avoidable and irreversible disability is a major current problem limiting patient outcomes. Lack of sufficient representation of DCM in undergraduate and postgraduate medical curricula may contribute to poor recognition of DCM by non-specialist doctors. The objective of this study was to assess the DCM teaching provision in UK medical schools and the DCM knowledge of UK medical students.

METHODS

UK medical students completed a web-based survey distributed nationally through university social media pages, university email bulletins and the national student network of Myelopathy.org. The survey comprised a 19-item questionnaire capturing data on student demographics, myelopathy teaching and myelopathy knowledge. Advertisements were repeated monthly over a 12-month recruitment period and participation was incentivised by entry into an Amazon voucher prize draw. Ethical approval for the study was granted by the Psychology Research Ethics Committee, University of Cambridge (PRE.2018.099).

RESULTS

A total of 751 medical students from 32 British medical schools completed the survey. Medical students from all year groups participated. Most students (520; 72%) had not received any medical school teaching about DCM. When students had received DCM teaching, the duration of teaching was minimal (75% < 1 h). A total of 350 students (47%) reported conducting private study on DCM. Modal student self-rating of their own knowledge of DCM was 'terrible' (356; 47%). There was no correlation between a student's subjective rating of their knowledge and their answers to objective questions. A total of 723 (96%) of students expressed interest in learning more about DCM, with lectures the preferred format.

CONCLUSIONS

DCM appears to be a neglected condition in medical education which has implications for clinical practice. However, student enthusiasm to undertake private study suggests future teaching interventions will be well-received. Future work is necessary to characterise the format of DCM teaching that is most effective and to subsequently measure how educational interventions translate into clinical benefits.

Cerebrospinal fluid pressure dynamics reveal signs of effective spinal canal narrowing in ambiguous spine conditions

Spinal canal narrowing with consecutive spinal cord compression is considered a key mechanism in degenerative cervical myelopathy (DCM). DCM is a common spine condition associated with progressive neurological disability, and timely decompressive surgery is recommended. However, the clinical and radiological diagnostic workup is often ambiguous, challenging confident proactive treatment recommendations. Cerebrospinal fluid pressure dynamics (CSFP) are altered by spinal canal narrowing. Therefore, we aim to explore the potential value of bedside CSFP assessments for qualitative and quantitative assessment of spinal canal narrowing in DCM. In this prospective case series, seven patients with DCM underwent bedside lumbar puncture with measurement of CSFP dynamics and routine CSF analysis (NCT02170155). The patients were enrolled when standard diagnostic algorithms did not permit a clear treatment decision. Measurements include baseline CSFP, cardiac-driven CSFP peak-to-trough amplitude (CSFPp), and the Queckenstedt's test (firm pressure on jugular veins) in neutral and reclined head position. From the Queckenstedt's test, proxies for craniospinal elastance (i.e., relative pulse pressure coefficient; RPPC-Q) were calculated analogously to infusion testing. CSFP metrics were deemed suspicious of canal narrowing when numbers were lower than the minimum value from a previously tested elderly spine-healthy cohort (N = 14). Mean age was 56 ± 13 years (range, 38–75; 2F); symptom severity was mostly mild to moderate (mean mJOA, 13.5 ± 2.6; range, 9–17). All the patients showed some extent of cervical stenosis in the MRI of unclear significance (5/7 following decompressive cervical spine surgery with an adjacent level or residual stenosis). Baseline CSFP was normal except for one patient (range, 4.7–17.4 mmHg). Normal values were found for CSFPp (0.4–1.3 mmHg) and the Queckenstedt's test in normal head positioning (9.-25.3 mmHg). During reclination, the Queckenstedt's test significantly decreased in one, and CSFPp in another case (>50% compared to normal position). RPPC-Q (0.07–0.19) aligned with lower values from spine-healthy (0.10–0.44). Routine CSF examinations showed mild total protein elevation (mean, 522 ± 108 mg/ml) without further evidence for the disturbed blood brain barrier. Intrathecal CSFP measurements allow discerning disturbed from normal CSFP dynamics in this population. Prospective longitudinal studies should further evaluate the diagnostic utility of CSFP assessments in DCM.

Comparative intra- and inter-observer reliability of two methods for evaluating intraoperative ultrasonography-based spinal cord hyperechogenicity intensity in degenerative cervical myelopathy

Objectives

During French-door laminoplasty, a linear array transducer of IOUS was used to observe and record the spinal cord decompression. To acquire a higher-reliability method, and compare the in-observer and inter-observer reliability of two methods in evaluating the hyperechoic intensity of spinal cord ultrasound in degenerative cervical myelopathy (DCM).

Background

The intensity of spinal cord hyperechogenicity is considered as a potential predictor of neurological recovery in DCM after decompression, but the accuracy of gray value ratio (GVR) is affected by many factors.

Methods

Totally 28 patients (20 males and 8 females) who had been followed up for 12 months were included. Their mean age at surgery was 61.2 ± 10.8 years and the average symptom duration was 23.36 ± 22.11 months. The gray values of circles 1, 2 and 3 were recorded as Gcompression, Gnorml and Gsac, respectively. Circle 1 was drawn with the maximum brightness point within the spinal cord as the center, circle 2 with the same area was plotted on the spinal cord with uniform echogenicity, without compression and at least 1 cm away from the circle 1, and circle 3 was drawn on the dorsal dural sac at the same segment as circle 1. GVR was calculated as follows: GVR-A = G_compression/G_norml (method A), and GVR-B = G_compression/G_sac (method B). The in-observer and inter-observer reliabilities of the two methods were compared. It is generally believed a reliability coefficient < 0.40 and > 0.75 indicate poor and good reliability respectively. The images-based GVR-B using this protocol demonstrates higher inter- and intraobserver reliabilities than GVR-A, and can be used as the basis for prognostic prediction and future studies.

Results

All examination acquisitions were successfully completed. GVR-A averaged 2.043 (0.318–5.56), and GVR-B averaged 0.578(0.06–1.41). GVR-B has better repeatability of gray value measurement, smaller relative standard deviation (RSD%) (0.298 vs. 0.32) and larger inter-group correlation coefficient compared with GVR-A. The mean value (MD) of the GVR difference calculated by GVR-B between the two clinicians was closer to 0.

Conclusions

For DCM patients routinely using ultrasound for real-time cord visualization during spinal cord decompression by French-door laminoplasty, the images-based GVR-B using this protocol demonstrates better inter- and intraobserver reliabilities compared with GVR-A.

Development of a core measurement set for research in degenerative cervical myelopathy: a study protocol (AO Spine RECODE-DCM CMS)

INTRODUCTION

Progress in degenerative cervical myelopathy (DCM) is hindered by inconsistent measurement and reporting. This impedes data aggregation and outcome comparison across studies. This limitation can be reversed by developing a core measurement set (CMS) for DCM research. Previously, the AO Spine Research Objectives and Common Data Elements for DCM (AO Spine RECODE-DCM) defined 'what' should be measured in DCM: the next step of this initiative is to determine 'how' to measure these features. This protocol outlines the steps necessary for the development of a CMS for DCM research and audit.

METHODS AND ANALYSIS

The CMS will be developed in accordance with the guidance developed by the Core Outcome Measures in Effectiveness Trials and the Consensus-based Standards for the selection of health Measurement Instruments. The process involves five phases. In phase 1, the steering committee agreed on the constructs to be measured by sourcing consensus definitions from patients, professionals and the literature. In phases 2 and 3, systematic reviews were conducted to identify tools for each construct and aggregate their evidence. Constructs with and without tools were identified, and scoping reviews were conducted for constructs without tools. Evidence on measurement properties, as well as on timing of assessments, are currently being aggregated. These will be presented in phase 4: a consensus meeting where a multi-disciplinary panel of experts will select the instruments that will form the CMS. Following selection, guidance on the implementation of the CMS will be developed and disseminated (phase 5). A preliminary CMS review scheduled at 4 years from release.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the University of Cambridge (HBREC2019.14). Dissemination strategies will include peer-reviewed scientific publications; conference presentations; podcasts; the identification of AO Spine RECODE-DCM ambassadors; and engagement with relevant journals, funders and the DCM community.