Summary
Myelopathies are neurological disorders due to compression of the spinal cord. Myelopathies can be cervical, thoracic, or lumbar. Cervical myelopathy is the most common type of myelopathy in adults above 55 years of age. Etiologies include degenerative changes of the spine, spinal trauma, infection, tumors, and autoimmune disorders. Onset can be acute, step-wise, or insidious. Clinical features vary depending on the level of the lesion and include local pain, stiffness, and impaired sensation, hypotonia, and hyporeflexia at the level of the lesion, and spasticity and hyperreflexia below the level of the injury level. Diagnosis is confirmed by MRI or myelography. Treatment includes conservative management for degenerative disease or immediate surgical decompression in acute compression.
Etiology
- Causes for compression of the spinal cord include:
- Blunt or penetrating trauma (e.g., fracture, epidural hematoma)
- Infection (e.g., abscess)
- Radiation therapy
- Autoimmune disorders (e.g., rheumatoid arthritis, neuromyelitis optica)
- Neoplasms (e.g., meningiomas, nerve sheath tumors, metastases) or cysts (e.g., epidermoid cysts)
- Ossification of the posterior longitudinal ligament (OPLL)
- Congenital narrowing of the cervical spinal canal
- Spinal stenosis
- Ankylosing spondylitis
- Discogenic myelopathy (central disc herniation)
- Multiple sclerosis
References:[1]
Pathophysiology
- Intramedullary or extramedullary (i.e., originating from within or outside the spinal cord) mass lesions compress the spinal cord and impair its perfusion; → mechanic and ischemic axonal injury → intramedullary edema → further narrowing of the medulla
References:[2]
Clinical features
Features depend on the level of compression and the onset may be sudden (e.g., with trauma), step-wise, or slowly progressive (e.g., degenerative diseases)
- Neck, shoulder, upper limb, or lower limb pain (neck stiffness may be present)
- 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 in lesions of the thoracic spine)
- Signs and symptoms of an upper motor neuron lesion below the level of the lesion; (e.g., abnormal spastic gait is often an early sign; hyperreflexia or a positive Babinski's sign may be present)
- Impaired sensation; (e.g., numbness; , impaired proprioception, ataxia)
- Impaired bladder and bowel control
Damage to the spinal cord and the nerve roots (radiculopathy) often occur simultaneously!
Pain is not commonly an early symptom. Therefore patients may not be diagnosed until myelopathy becomes severe!
References:[1][3]
Diagnostics
- MRI of the spine: : determines the site of narrowing of the medulla and the underlying pathology
- Myelography: (possibly with CT): when MRI is contraindicated (e.g., in patients with metal implants)
References:[2][4]
Differential diagnoses
- Subacute combined degeneration of the spinal cord
- Amyotrophic lateral sclerosis (Lou Gehrig's disease)
- Syringomyelia
References:[4][5]
The differential diagnoses listed here are not exhaustive.
Treatment
- Conservative treatment: (i.e., analgesia; , corticosteroid; therapy , bracing; , physiotherapy; ): indicated perioperatively; , for severe cases (e.g., degenerative cervical myelopathy ), and mild cases
- Decompression surgery: : typically indicated in acute or advanced cases
Acute cervical myelopathy with loss of bladder and bowel control is a neurological emergency that demands immediate surgical decompression!
References:[3][5]