Degenerative Cervical Myelopathy: An Overview

Abstract

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

Keywords: anatomy; anterior cervical discectomy fusion; degenerative cervical myelopathy; literature review; modified japanese orthopaedic association score; musculoskeletal imaging; posterior cervical decompression and fusion; spinal surgery complication; surgical management of spine.

Figure 1. A drawing of the cervical spine anatomy including blood supply and nerve location.

This is the original work of the authors.

Figure 2. A cross-sectional drawing of the cervical spinal cord. This demonstrates the location of the spinal tracts within the spinal cord that can be affected by degenerative cervical myelopathy.

CF = cuneatus fasciculus; GF = gracile fasciculus This is the original work of the authors.

Figure 3. A sagittal drawing of the cervical spine depicting the degenerative changes involved in degenerative cervical myelopathy.

Degenerative changes within the cervical spine include changes to the vertebral body such as loss of height, increased anterior-posterior length, and hourglass reshaping. The vertebral body can become hypermobile and lead to spondylolisthesis. Osteophyte formation can occur leading to anterior compression of the spinal cord. The intervertebral (IV) disc can degenerate and lead to loss of IV height and protrusion. The posterior longitudinal ligament (PLL) and ligamentum flavum (LF) can also be affected through hypertrophy and ossification. Points of compression are highlighted in red on the illustration. This is the original work of the authors.