What is cervical myelopathy?

What is Cervical Myelopathy

Cervical myelopathy is a neurologic condition caused by chronic progressive compression of the spinal cord in the neck due to degenerative changes of the cervical spine, including disc degeneration, bone spurs (osteophytes), and spinal canal narrowing. 1, 2

Pathophysiology

• The disease process begins with progressive disc degeneration, leading to narrowing of the cervical canal, primarily from osteophytes growing from the posterior edges of vertebrae 3
• Compression typically affects the C5-C7 levels most commonly 4
• Over time, the chronic compression produces both static factors (fixed anatomical narrowing) and dynamic factors (movement-related cord injury) 1
• Pathological progression worsens with duration and degree of anteroposterior (AP) compression, showing a pattern of gray matter cavitation and white matter demyelination similar to transient hypoperfusion syndrome 5
• When AP compression reaches 40-44% of normal, flattening of gray matter with mild demyelination occurs; at 22-39%, small cavitation develops with diffuse demyelination; at 12-19%, extensive gray matter necrosis with white matter gliosis occurs 5

Clinical Presentation

The hallmark symptoms include decreased hand dexterity (hand clumsiness), gait instability with wide-based gait, and progressive sensory and motor dysfunction. 4, 1

• Upper extremity symptoms: Hand clumsiness, numbness or tingling in arms/hands, weakness in specific muscle groups 6
• Lower extremity symptoms: Generalized weakness or stiffness in legs, wide-based gait 6, 4
• Autonomic symptoms: Bowel and bladder dysfunction may develop in severe cases 4
• Symptoms develop insidiously over time and progress gradually 1, 2
• Atypical presentations can occur, such as isolated lower extremity symptoms without upper extremity involvement 4

Epidemiology and Natural History

• Cervical spondylotic myelopathy (CSM) is the most common form of spinal cord injury in adults, typically affecting individuals aged 55 and older 4, 1
• It is an increasingly prevalent and devastating disorder that causes functional decline, reduced independence, and diminished quality of life 2
• The natural history is variable: approximately 70% of patients with mild CSM maintain stable clinical status over 3 years with nonoperative treatment 6
• In studies of untreated patients, 75% experienced episodic progression with new symptoms appearing in stepwise fashion, while 20% showed slow steady progression and 5% had rapid onset followed by plateau 5
• Approximately 80% of patients younger than 75 years with mild CSM (modified Japanese Orthopaedic Association score >12) do not worsen over time and may occasionally improve 5

Prognostic Factors

• Younger age correlates with better outcomes 5, 7
• Shorter duration of symptoms predicts better prognosis 7
• Milder preoperative disability is associated with better outcomes 5, 6
• Poor prognostic factors include female gender, older age, increased range of motion, and longer symptom duration 5, 7

Common Pitfalls

• Diagnosis is often delayed because symptoms develop insidiously and may be attributed to normal aging 1
• Cervical spine imaging shows degenerative changes in most people over 30 years, which correlate poorly with symptoms—do not rely solely on imaging for diagnosis 7
• Patients presenting with isolated lower extremity symptoms may have cervical pathology missed if cervical spine is not evaluated 4
• Primary degenerative spinal cord diseases (amyotrophic lateral sclerosis, primary progressive spastic paralysis) can mimic CSM in the same age group, leading to unnecessary surgery 3
• Asymptomatic cervical cord compression does not warrant prophylactic surgery, as this remains controversial and is not standard of care 8