Summary
Cervical myelopathy is a type of myelopathy that is caused by axonal injury of the cervical spinal cord, either by direct compression or ischemic injury due to compression of the anterior spinal artery. The most common cause is cervical spondylotic myelopathy. Other etiologies include spinal trauma, neoplasms, epidural abscess, and autoimmune disorders. Onset can be acute, insidious, or progress in a stepwise fashion. Clinical features include neck pain and stiffness, impaired sensation in the hands and arms, weakness, poor manual dexterity, and gait instability. The diagnosis is confirmed by MRI. Treatment includes conservative management for mild disease without functional impairment or surgical decompression in acute or severe disease with functional impairment.
Etiology
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Cervical spondylotic myelopathy (most common)
- Compression of the cervical spinal cord as a result of a degenerative process
- Typically occurs in adults > 50 years of age
- Trauma (e.g., fracture, epidural hematoma)
- Tumors (e.g., meningiomas, nerve sheath tumors, metastases, epidermoid cysts)
- Spinal epidural abscess
- Radiation therapy
- Autoimmune disorders (e.g., rheumatoid arthritis)
- Discogenic myelopathy (central disk herniation)
- Cervical kyphosis
- Congenital spinal stenosis
- Ossification of the posterior longitudinal ligament (OPLL)
References:[1][2]
Pathophysiology
- Cervical myelopathy is characterized by axonal injury in the cervical spinal cord due to:
- Direct injury caused by compression of the cervical spinal cord
- Ischemic injury caused by compression of the anterior spinal artery
References:[3]
Clinical features
Clinical features depend on the level of compression. Symptoms may be acute in onset (e.g., with trauma) or progress slowly (e.g., degenerative diseases) or in a step-wise fashion.
- Neck pain and stiffness
- Impaired sensation in the hands and arms (e.g., diffuse numbness, paresthesias)
- Gait instability (often an early sign), impaired proprioception
- Weakness and clumsiness (poor manual dexterity) in the hands and arms
- Signs and symptoms of lower motor neuron lesions at the level of the lesion (e.g., weakness and atrophy in the arms and/or hands, hyporeflexia)
- Signs and symptoms of an upper motor neuron lesion below the level of the lesion (e.g., weakness, increased tone, hyperreflexia, or a positive Babinski sign)
- Positive Lhermitte sign
- Impaired bladder and bowel control (rare)
Injury to the spinal cord and the nerve roots (radiculopathy) often occurs simultaneously!
Pain is often absent in early stages. Therefore, a high index of suspicion is needed to make an early diagnosis and prevent progression of functional impairment due to spinal cord injury!
References:[1][4][5]
Diagnosis
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Cervical x-ray : initial imaging test
- Reduced diameter of the spinal canal
- Degenerative changes of vertebral joints
- Osteophyte formation
- Narrowing of the disk space
- MRI of the spine (imaging modality of choice) : determines the site of narrowing of the medulla and the underlying pathology
- Myelography (possibly with CT): if MRI is contraindicated (e.g., in patients with metal implants)
- Electromyography for nerve conduction studies of peripheral nerves: helps differentiate peripheral injury (e.g., carpal tunnel syndrome) from cervical myelopathy
References:[3][6]
Differential diagnoses
References:[2][5][6]
The differential diagnoses listed here are not exhaustive.
Treatment
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Conservative treatment
- Indications: mild cases with no functional impairment, nonsurgical candidates, perioperative management
- Analgesia with an NSAID or corticosteroid therapy
- Immobilization via bracing
- Physiotherapy
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Surgical treatment: decompression and stabilization of the cervical spine
- Indications: acute or severe cases with functional impairment
- Techniques: e.g., anterior cervical discectomy and fusion, posterior laminectomy and fusion
Acute cervical myelopathy with loss of bladder and bowel control is a neurological emergency that demands immediate surgical decompression!
References:[2][4]