Table of Contents
Degenerative cervical myelopathy
Neurosurgery Service, General University Hospital Alicante, Alicante, Spain.
The assessment, diagnosis, operative and nonoperative management of degenerative cervical myelopathy (DCM) have evolved rapidly over the last 20 years. A clearer understanding of the pathobiology of DCM has led to attempts to develop objective measurements of the severity of myelopathy, including technology such as multiparametric magnetic resonance imaging, biomarkers, and ancillary clinical testing. New pharmacological treatments have the potential to alter the course of surgical outcomes, and greater innovation in surgical techniques have made surgery safer, more effective and less invasive. Future developments for the treatment of DCM will seek to improve the diagnostic accuracy of imaging, improve the objectivity of clinical assessment, and increase the use of surgical techniques to ensure the best outcome is achieved for each individual patient 1).
Goel was troubled by the fact that his several PubMed and MEDLINE indexed articles on the subject published in leading journals dedicated to the study of the spine have not found any place in the huge reference list of 137 articles 2)
Definition
Epidemiology
Classification
Etiology
Pathogenesis
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. 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).
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.
The rapidly expanding literature provides mounting evidence for brain changes in DCM. Rafati Fard et al. 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 3)
Pathophysiology
A review of Tetreault et al. summarizes current knowledge of the pathophysiology of DCM and describes the cascade of events that occur after compression of the spinal cord, including ischemia, destruction of the blood-spinal cord barrier, demyelination, and neuronal apoptosis. Important features of the diagnosis of DCM are discussed in detail, and relevant clinical and imaging findings are highlighted. Furthermore, this review outlines valuable assessment tools for evaluating functional status and quality of life in these patients and summarizes the advantages and disadvantages of each. Other topics of this review include epidemiology, the prevalence of degenerative changes in the asymptomatic population, the natural history and rates of progression, risk factors of diagnosis (clinical, imaging and genetic), and management strategies 4).
Histological findings
MEDLINE and Embase were systematically searched (CRD42021281462) for primary research reporting on histological findings of DCM in the human cadaveric spinal cord tissue. Data were extracted using a piloted proforma. The 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).
The search yielded 4127 unique records. After the 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 hematoxylin 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.
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 underutilized but complementary approach 5).
Clinical features
Scales
As a widespread used scale, the Modified Japanese Orthopaedic Association scale (mJOA) should be translated and culturally adapted 6).
Diagnosis
Differential diagnosis
Treatment
Outcome
Research
Randomized, controlled trials
A National Institutes of Health-funded (1R13AR065834-01) investigator meeting was held before the initiation of the trial to bring multiple stakeholders together to finalize the study protocol. Study investigators, coordinators, and major stakeholders were able to attend and discuss strengths of, limitations of, and concerns about the study. The final protocol was approved for funding by the Patient-Centered Outcomes Research Institute (CE-1304-6173). The trial began enrollment on April 1, 2014 7).
Case series
Case reports
Degenerative cervical myelopathy cases from the General University Hospital of Alicante
A 65-year-old woman with a complex medical history, presented with a 9-month progressive history of bilateral hand numbness, frequent falls, and burning bilateral brachialgia. Her medical background included hypertension, dyslipidemia, obesity, perinatal anoxic encephalopathy with resultant neurological sequelae (tetraparesis, ataxia, nystagmus, dysarthria), a past traumatic vertebral fracture, and previous lumbar spine surgeries in 2000.
Presenting Symptoms:
She reported a gradual onset of numbness in both hands, leading to difficulty in grip strength and frequent object dropping. Increased instability in walking and falls were also noted, accompanied by intense burning bilateral arm pain radiating cephalically. Anosmia for over a year and no sphincter control impairment were reported.
Neurological Examination: The neurological examination revealed focal deficits, including reduced strength in upper and lower limbs, tactile hypoesthesia in both hands, and preserved proprioceptive sensitivity in the lower limbs.
Imaging studies, including cervical MRI, confirmed canal stenosis at the C3-C4 level with significant spinal cord signal alteration consistent with myelopathy.
Surgical Intervention:
She underwent a cervical laminoplasty at the C3-C4 level. The surgery proceeded without complications. Postoperatively, there was a subjective improvement in sensory symptoms in both upper limbs, though no immediate changes were noted in the physical examination.
Postoperative Management: The patient's postoperative course was uneventful. She reported controlled cervical pain, tolerated sitting and oral intake, and exhibited diuresis. Due to good postoperative recovery, the initial plan for transfer to a reference hospital for progressive mobilization was reconsidered based on the patient's desire for home discharge.
Follow-up and Rehabilitation Plan:
She was prescribed a comprehensive follow-up plan, including wound care, pain management, and medications. A rehabilitation plan for progressive mobilization was established. Follow-up appointments were scheduled with the primary care physician and neurosurgery outpatient clinic. Social work involvement aimed to address the patient's social needs and support.
Conclusion: This case highlights the successful surgical intervention in a complex patient with cervical myelopathy. Despite the underlying neurological sequelae and comorbidities, the patient showed subjective improvement postoperatively. A multidisciplinary approach involving neurosurgery, rehabilitation, and social work was essential for comprehensive patient care.
This case report emphasizes the importance of tailored management plans in addressing cervical myelopathy, considering individual patient factors and promoting collaborative care among medical specialties. Regular follow-up and rehabilitation efforts will contribute to optimizing the patient's long-term outcomes.