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Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults worldwide. DCM encompasses various acquired (age-related) and congenital pathologies related to degeneration of the cervical spinal column, including hypertrophy and/or calcification of the ligaments, intervertebral discs and osseous tissues. These pathologies narrow the spinal canal, leading to chronic spinal cord compression and disability. Owing to the ageing population, rates of DCM are increasing. Expeditious diagnosis and treatment of DCM are needed to avoid permanent disability. Over the past 10 years, advances in basic science and in translational and clinical research have improved our understanding of the pathophysiology of DCM and helped delineate evidence-based practices for diagnosis and treatment. Surgical decompression is recommended for moderate and severe DCM; the best strategy for mild myelopathy remains unclear. Next-generation quantitative microstructural MRI and neurophysiological recordings promise to enable quantification of spinal cord tissue damage and help predict clinical outcomes. Here, we provide a comprehensive, evidence-based review of DCM, including its definition, epidemiology, pathophysiology, clinical presentation, diagnosis and differential diagnosis, and non-operative and operative management. With this Review, we aim to equip physicians across broad disciplines with the knowledge necessary to make a timely diagnosis of DCM, recognize the clinical features that influence management and identify when urgent surgical intervention is warranted.

Background: There is controversy over the optimal treatment strategy for patients with mild degenerative cervical myelopathy (DCM)., Objective: To evaluate the degree of impairment in baseline quality of life as compared to population norms, as well as functional, disability, and quality of life outcomes following surgery in a prospective cohort of mild DCM patients undergoing surgical decompression., Methods: We identified patients with mild DCM (modified Japanese Orthopaedic Association [mJOA] 15 to 17) enrolled in the prospective, multicenter AOSpine CSM-NA or CSM-I trials. Baseline quality of life Short Form-36 version 2 (SF-36v2) was compared to population norms by the standardized mean difference (SMD). Outcomes, including functional status (mJOA, Nurick grade), disability (NDI [Neck Disability Index]), and quality of life (SF-36v2), were evaluated at baseline and 6 mo, 1 yr, and 2 yr after surgery. Postoperative complications within 30 d of surgery were monitored., Results: One hundred ninety-three patients met eligibility criteria. Mean age was 52.4 yr. There were 67 females (34.7%). Patients had significant impairment in all domains of the SF-36v2 compared to population norms, greatest for Social Functioning (SMD -2.33), Physical Functioning (SMD -2.31), and Mental Health (SMD -2.30). A significant improvement in mean score from baseline to 2-yr follow-up was observed for all major outcome measures, including mJOA (0.87, P < .01), Nurick grade (-1.13, P < .01), NDI (-12.97, P < .01), and SF-36v2 Physical Component Summary (PCS) (5.75, P < .01) and Mental Component Summary (MCS) (6.93, P < .01). The rate of complication was low., Conclusion: Mild DCM is associated with significant impairment in quality of life. Surgery results in significant gains in functional status, level of disability, and quality of life., (© Congress of Neurological Surgeons 2018.)

Objective: Intraoperative neurophysiological monitoring (IONM) is a useful adjunct in spine surgery, with proven benefit in scoliosis-correction surgery. However, its utility for anterior cervical discectomy and fusion (ACDF) is unclear, as there are few head-to-head comparisons of ACDF outcomes with and without the use of IONM. The authors sought to evaluate the impact of IONM on the safety and cost of ACDF., Methods: This was a retrospective analysis of data from the National (Nationwide) Inpatient Sample of the Healthcare Cost and Utilization Project from 2009 to 2013. Patients with a primary procedure code for ACDF were identified, and diagnosis codes were searched to identify cases with postoperative neurological complications. The authors performed univariate and multivariate logistic regression for postoperative neurological complications with use of IONM as the independent variable; additional covariates included age, sex, surgical indication, multilevel fusion, Charlson Comorbidity Index (CCI) score, and admission type. They also conducted propensity score matching in a 1:1 ratio (nearest neighbor) with the use of IONM as the treatment indicator and the aforementioned variables as covariates. In the propensity score-matched cohort, they compared neurological complications, length of stay (LOS), and hospital charges (in US dollars)., Results: A total of 141,007 ACDF operations were identified. IONM was used in 9540 cases (6.8%). No significant association was found between neurological complications and use of IONM on univariate analysis (OR 0.80, p = 0.39) or multivariate regression (OR 0.82, p = 0.45). By contrast, age ≥ 65 years, multilevel fusion, CCI score > 0, and a nonelective admission were associated with greater incidence of neurological complication. The propensity score-matched cohort consisted of 18,760 patients who underwent ACDF with (n = 9380) or without (n = 9380) IONM. Rates of neurological complication were comparable between IONM and non-IONM (0.17% vs 0.22%, p = 0.41) groups. IONM and non-IONM groups had a comparable proportion of patients with LOS ≥ 2 days (19% vs 18%, p = 0.15). The use of IONM was associated with an additional $6843 (p < 0.01) in hospital charges., Conclusions: The use of IONM was not associated with a reduced rate of neurological complications following ACDF. Limitations of the data source precluded a specific assessment of the effectiveness of IONM in preventing neurological complications in patients with more complex pathology (i.e., ossification of the posterior longitudinal ligament or cervical deformity).

Background Context: Predictors of outcome after surgery for degenerative cervical myelopathy (DCM) have been determined previously through hypothesis-driven multivariate statistical models that rely on a priori knowledge of potential confounders, exclude potentially important variables because of restrictions in model building, cannot include highly collinear variables in the same model, and ignore intrinsic correlations among variables., Purpose: The present study aimed to apply a data-driven approach to identify patient phenotypes that may predict outcomes after surgery for mild DCM., Study Design: This is a principal component analysis of data from two related prospective, multicenter cohort studies., Patient Sample: The study included patients with mild DCM, defined by a modified Japanese Orthopaedic Association score of 15-17, undergoing surgical decompression as part of the AOSpine CSM-NA or CSM-I trials., Outcome Measures: Patient outcomes were evaluated preoperatively at baseline and at 6 months, 1 year, and 2 years after surgery. Quality of life (QOL) was evaluated by the Neck Disability Index (NDI) and Short Form-36 version 2 (SF-36v2). These are both patient self-reported measures that evaluate health-related QOL, with NDI being specific to neck conditions and SF-36v2 being a generic instrument., Materials and Methods: The analysis included 154 patients. A heterogeneous correlation matrix was created using a combination of Pearson, polyserial, and polychoric regressions among 67 variables, which then underwent eigen decomposition. Scores of significant principal components (PCs) (with eigenvalues>1) were included in multivariate logistic regression analyses for three dichotomous outcomes of interest: achievement of the minimum clinically important difference [MCID] in (1) NDI (≤-7.5), (2) SF-36v2 Physical Component Summary (PCS) score (≥5), and (3) SF-36v2 Mental Component Summary (MCS) score (≥5)., Results: Twenty-four significant PCs accounting for 75% of the variance in the data were identified. Two PCs were associated with achievement of the MCID in NDI. The first (PC 1) was dominated by variables related to surgical approach and number of operated levels; the second (PC 21) consisted of variables related to patient demographics, severity and etiology of DCM, comorbid status, and surgical approach. Both PC 1 and PC 21 also correlated with SF-36v2 PCS score, in addition to PC 4, which described patients' physical profile, including gender, height, and weight, as well as comorbid renal disease; PC 6, which received large loadings from variables related to cardiac disease, impaired mobility, and length of surgery and recovery; and PC 9, which harbored large contributions from features of upper limb dysfunction, cardiorespiratory disease, surgical approach, and region. In addition to PC 21, a component profiling patients' socioeconomic status and support systems and degree of physical disability (PC 24) was associated with achievement of the MCID in SF-36 MCS score., Conclusions: Through a data-driven approach, we identified several phenotypes associated with disability and physical and mental health-related QOL. Such data reduction methods may separate patient-, disease-, and treatment-related variables more accurately into clinically meaningful phenotypes that may inform patient care and recruitment into clinical trials., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Study Design: Post-hoc analysis of 606 patients enrolled in the AOSpine CSM-NA or CSM-I prospective, multicenter cohort studies., Objective: The aim of this study was to determine the minimum clinically important difference (MCID) in SF-36v2 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores in patients undergoing surgery for degenerative cervical myelopathy (DCM)., Summary of Background Data: There has been a shift toward focus on patient-reported outcomes (PROs) in spine surgery. However, the numerical scores of PROs lack immediate clinical meaning. The MCID adds a dimension of interpretability to PRO scales; by defining the smallest change, a patient would consider meaningful., Methods: The MCID of the SF-36v2 PCS and MCS were determined by distribution- and anchor-based methods comparing preoperative to 12-month scores. Distribution-based approaches included calculation of the half standard deviation and standard error of measurement (SEM). Change in Neck Disability Index (NDI) served as the anchor: "worse" (ΔNDI>7.5); "unchanged" (7.5≥ΔNDI>-7.5); "slightly improved" (-7.5≥ΔNDI>-15); and "markedly improved" (ΔNDI ≤-15). Receiver operating characteristic (ROC) analysis was performed to determine the change score for the MCID with even sensitivity and specificity to distinguish patients who were "slightly improved" versus "unchanged" on the NDI., Results: The MCID for the SF-36v2 PCS and MCS were 4.6 and 6.8 by half standard deviation and 2.9 and 4.3 by SEM, respectively. By ROC analysis, the MCID was 3.9 for the SF-36v2 PCS score and 3.2 for the SF-36v2 MCS score. Using a cutoff of 4 points, the SF-36v2 PCS had a sensitivity of 72.2% and specificity of 68.1%, and MCS 61.9% and 64.6%, respectively, in separating patients who were "markedly improved" or "slightly improved" from those who were "unchanged" or "worse.", Conclusion: We found the MCID of the SF-36v2 PCS and MCS to be 4 points. This will facilitate use of the SF-36v2 as an outcome in future studies of DCM., Level of Evidence: 3.

Study Design: Systematic review and meta-analysis., Objective: To evaluate the clinical and functional outcomes of transection of the C2 roots during C1 lateral mass screw placement for atlantoaxial fixation., Summary of Background Data: Transection of the C2 nerve roots has been recommended during atlantoaxial fixation to facilitate C1 lateral mass screw placement and possibly reduce postoperative occipital neuralgia, although this practice remains controversial., Methods: We searched MEDLINE, EMBASE, Web of Science, and the Cochrane Library for studies evaluating the outcomes of C1-2 fixation involving sacrifice of the C2 roots. We calculated transformed proportions with 95% confidence intervals (CI) for the outcomes of occipital neuralgia, numbness, bony fusion, and procedural morbidity. For studies comparing C2 transection with nerve sparing surgery, we performed meta-analyses for the outcomes of occipital neuralgia, occipital numbness, blood loss, and operative time., Results: Eight observational studies (N = 393) met eligibility criteria. The rate of postoperative occipital neuralgia among included studies was 0% to 25%; occipital numbness, 6.7% to100%; bony fusion, 96.7% to 100%; and procedural morbidity, 0% to 14.3%. Among comparative studies, C2 transection was associated with a higher rate of occipital numbness [odds ratio (OR) 178.6 (95% CI 26.6 to 1198.4)], lower blood loss [mean difference (MD) -195.3 mL (95% CI -317.7 to -72.8 mL)] and shorter operative times [MD -57.5 mins (95% CI -76.9 to -38.2 mins)] than when the C2 roots were spared. We found no difference in rates of occipital neuralgia [OR 1.44 (95% CI 0.45 to 4.68)]., Conclusion: Transection of the C2 nerve roots appears to be a viable, safe option when undertaking placement of C1 lateral mass screws. The procedure is associated with reduced operative duration and blood loss, increased rate of occipital numbness, and no change in the rate of occipital neuralgia. However, given the relatively low quality of evidence, prospective, controlled studies to evaluate this strategy are recommended., Level of Evidence: N /A.

Background: Cervical spine clearance protocols are controversial for unconscious patients after blunt traumatic injury and negative findings on computed tomography (CT)., Purpose: To review evidence about the utility of different cervical spine clearance protocols in excluding significant cervical spine injury after negative CT results in obtunded adults with blunt traumatic injury., Data Sources: MEDLINE, EMBASE, CINAHL, Google Scholar, and the Cochrane Library were searched from January 2000 through November 2014., Study Selection: English-language studies that examined patients with negative CT results having confirmatory routine testing with magnetic resonance imaging (MRI), dynamic radiography, or clinical examination and that reported outcome measures of missed cervical spine injury, need for operative stabilization, or prolonged use of cervical collars., Data Extraction: Independent reviewers evaluated the quality of studies and abstracted the data according to a predefined protocol., Data Synthesis: Of 28 observational studies (3627 patients) that met eligibility criteria, 7 were prospective studies (1686 patients) with low risk of bias and well-interpreted, high-quality CT scans. These 7 studies showed that 0% of significant injuries were missed after negative CT results. The overall studies using confirmatory routine testing with MRI showed incidence rates of 0% to 1.5% for cervical spine instability (16 studies; 1799 patients), 0% to 7.3% for need for operative fixation (17 studies; 1555 patients), and 0% to 29.5% for prolonged collar use (16 studies; 1453 patients)., Limitations: Most studies were retrospective. Approaches to management of soft tissue changes with collars varied markedly., Conclusion: Cervical spine clearance in obtunded adults after blunt traumatic injury with negative results from a well-interpreted, high-quality CT scan is probably a safe and efficient practice., Primary Funding Source: None.

Cervical spinal cord injury (SCI) can result in devastating functional deficits that involve the respiratory and hand function. The mammalian spinal cord has limited ability to regenerate and restore meaningful functional recovery following SCI. Riluzole, 2-amino-6-trifluoromethoxybenzothiazole, an anti-glutamatergic drug has been shown to reduce excitotoxicity and confer neuroprotection at the site of injury following experimental SCI. Based on promising preclinical studies, riluzole is currently under Phase III clinical trial for the treatment of SCI ( ClinicalTrials.gov : NCT01597518 ). Riluzole's anti-glutamatergic role has the potential to regulate neuronal function and provide neuroprotection and influence glutamatergic connections distal to the initial injury leading to enhanced functional recovery following SCI. In order to investigate this novel role of riluzole we used a high cervical hemisection model of SCI, which interrupts all descending input to motoneurons innervating the ipsilateral forelimb and diaphragm muscles. Following C2 spinal cord hemisection, animals were placed into one of two groups: one group received riluzole (8 mg/kg) 1 h after injury and every 12 h thereafter for 7 days at 6 mg/kg, while the second group of injured rats received vehicle solution for the same duration of time. A third group of sham injured rats underwent a C2 laminectomy without hemisection and served as uninjured control rats. Interestingly, this study reports a significant loss of motoneurons within the cervical spinal cord caudal to C2 hemisection injury. Disruption of descending input led to a decrease in glutamatergic synapses and motoneurons caudal to the injury while riluzole treatment significantly limited this decline. Functionally, Hoffmann reflex recordings revealed an increase in the excitability of the remaining ipsilateral cervical motoneurons and significant improvements in skilled and unskilled forelimb function and respiratory motor function in the riluzole-treated animals. In conclusion, using a C2 hemisection injury model, this study provides novel evidence of motoneuron loss caudal to the injury and supports riluzole's capacity to promote neuronal preservation and function of neural network caudal to the SCI resulting in early and sustained functional improvements. [ABSTRACT FROM AUTHOR]