Degenerative Cervical Myelopathy: A Clinical Review

Abstract

Degenerative Cervical Myelopathy (DCM) is the most common form of spinal cord impairment in adults and results in disability and reduced quality of life. DCM can present with a wide set of clinical and imaging findings, including: 1) pain and reduced range of motion of the neck, and motor and sensory deficits on clinical exam, and 2) cord compression due to static and dynamic injury mechanisms resulting from degenerative changes of the bone, ligaments, and intervertebral discs on MRI. The incidence and prevalence of DCM has been estimated at a minimum of 4.1 and 60.5 per 100,000, respectively, but surgical trends and an aging population suggest these numbers will rise in the future. The diagnosis of DCM is based on clinical examination, with a positive Hoffmann's sign and hand numbness typically appearing in the upper limbs, and gait abnormalities such as difficulty with tandem gait serving as sensitive diagnostic findings. Loss of bladder function may also occur in patients with severe DCM. The degree of neurological impairment can be measured using the modified Japanese Association Scale (mJOA) or Nurick grade. Non-operative management has a limited role in the treatment, while surgical management has been shown to both be safe and effective for halting disease progression and improving neurological function. Predictors of surgical outcome include age and baseline severity, indicating that early recognition of DCM is important for ensuring an optimal surgical outcome.

Keywords: Cervical Spondylotic Myelopathy; compressive myelopathy; pain; sensation.

Figure 1

Illustration of the various gross anatomic pathophysiologic changes that contribute to degenerative cervical myelopathy. PLL, posterior longitudinal ligament; CSF, cerebrospinal fluid. Originally published by Nouri et al. (2015) [2], medical illustration by Diana Kryski (Kryski Biomedia).

Figure 2

Cervical disc bulge in a 40-year-old man. In the neutral position (A), T2-weighted sagittal MR image shows C4/5, C5/6, and C6/7 levels disc bulge. In flexion (B) and extension (C), the disc bulge is increased, especially in the C6/7 level. Adapted with permission, Springer Nature. European Spine Journal. Missed cervical disc bulges diagnosed with kinematic magnetic resonance imaging. Lao L, Daubs MD, Scott TP, Phan KH, Wang JC. Copyright 2014.

Figure 3

Types of signal changes that can appear in patients with DCM. A-D: Sagittal T2WI. A: Type I, diffuse and faint hyperintensity. B: Type II, focal and sharp hyperintensity. C: Type III, both Type I (higher arrow) and Type II (lower arrow) hyperintensity characteristics are present. D: Two discontinuous focal hyperintensities are present. E: Sagittal MRI with T1WI showing a focal hypointensity. Originally published in Nouri et al. (2016) [16]. Reprinted with permission from Neurosurgical Focus.