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.

Adverse Events Relating to Prolonged Hard Collar Immobilisation: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To evaluate systematically the complications of prolonged cervical immobilisation in a hard collar. METHODS: Following registration with PROSPERO, a systematic search of electronic databases (MEDLINE, EMBASE) was conducted. Two reviewers independently screened the search results according to pre-determined search criteria. Data was extracted and tabulated. Joanna Briggs Institute checklists were used for assessing the quality of included studies. RESULTS: The search identified 773 articles. A total of 25 studies were selected for final inclusion. The results largely comprised a mixture of case reports/series, cohort studies and reviews. The most commonly reported complications were pressure ulcers, dysphagia and increased intracranial pressure. A pressure ulcer pooled prevalence of 7% was calculated. There was insufficient data for quantitative analysis of any other complication. CONCLUSIONS: There is significant morbidity from prolonged hard collar immobilisation, even amongst younger patients. Whilst based upon limited and low-quality evidence, these findings, combined with the low-quality evidence for the efficacy of hard collars, highlights a knowledge gap for future research.

Clinical outcome measures and their evidence base in degenerative cervical myelopathy: a systematic review to inform a core measurement set (AO Spine RECODE-DCM).

OBJECTIVES: To evaluate the measurement properties of outcome measures currently used in the assessment of degenerative cervical myelopathy (DCM) for clinical research. DESIGN: Systematic review DATA SOURCES: MEDLINE and EMBASE were searched through 4 August 2020. ELIGIBILITY CRITERIA: Primary clinical research published in English and whose primary purpose was to evaluate the measurement properties or clinically important differences of instruments used in DCM. DATA EXTRACTION AND SYNTHESIS: Psychometric properties and clinically important differences were both extracted from each study, assessed for risk of bias and presented in accordance with the Consensus-based Standards for the selection of health Measurement Instruments criteria. RESULTS: Twenty-nine outcome instruments were identified from 52 studies published between 1999 and 2020. They measured neuromuscular function (16 instruments), life impact (five instruments), pain (five instruments) and radiological scoring (five instruments). No instrument had evaluations for all 10 measurement properties and <50% had assessments for all three domains (ie, reliability, validity and responsiveness). There was a paucity of high-quality evidence. Notably, there were no studies that reported on structural validity and no high-quality evidence that discussed content validity. In this context, we identified nine instruments that are interpretable by clinicians: the arm and neck pain scores; the 12-item and 36-item short form health surveys; the Japanese Orthopaedic Association (JOA) score, modified JOA and JOA Cervical Myelopathy Evaluation Questionnaire; the neck disability index; and the visual analogue scale for pain. These include six scores with barriers to application and one score with insufficient criterion and construct validity. CONCLUSIONS: This review aggregates studies evaluating outcome measures used to assess patients with DCM. Overall, there is a need for a set of agreed tools to measure outcomes in DCM. These findings will be used to inform the development of a core measurement set as part of AO Spine RECODE-DCM.