(See also Overview of Spinal Cord Disorders Overview of Spinal Cord Disorders Spinal cord disorders can cause permanent severe neurologic disability. For some patients, such disability can be avoided or minimized if evaluation and treatment are rapid. The spinal cord... read more and Immediate care for spinal trauma Immediate care Trauma to the spine may cause injuries involving the spinal cord, vertebrae, or both. Occasionally, the spinal nerves are affected. The anatomy of the spinal column is reviewed elsewhere. Spinal... read more .)
Compression is caused far more commonly by lesions outside the spinal cord (extramedullary) than by lesions within it (intramedullary).
Compression may be
Acute compression develops within minutes to hours. It is often due to
Trauma (eg, vertebral crush fracture Vertebral Compression Fractures Most vertebral compression fractures are a consequence of osteoporosis, are asymptomatic or minimally symptomatic, and occur with no or minimal trauma. (See also Overview of Fractures.) Vertebral... read more with displacement of fracture fragments, acute disk herniation Cervical Herniated Nucleus Pulposus Herniated nucleus pulposus is prolapse of an intervertebral disk through a tear in the surrounding annulus fibrosus. The tear causes pain due to irritation of sensory nerves in the disk, and... read more , severe bone or ligamentous injury causing hematoma, vertebral subluxation or dislocation)
It is occasionally due to abscess and rarely due to spontaneous epidural hematoma. Acute compression may follow subacute and chronic compression, especially if the cause is abscess or tumor.
Subacute compression develops over days to weeks. It is usually caused by
A metastatic extramedullary tumor
A subdural or an epidural abscess or hematoma
A cervical or, rarely, thoracic herniated disk
Chronic compression develops over months to years. It is commonly caused by
Bony protrusions into the cervical, thoracic, or lumbar spinal canal (eg, due to osteophytes or spondylosis, especially when the spinal canal is narrow, as occurs in spinal stenosis Lumbar Spinal Stenosis Lumbar spinal stenosis is narrowing of the lumbar spinal canal causing compression of the nerve rootlets and nerve roots in the cauda equina before their exit from the foramina. It causes positional... read more )
Compression can be aggravated by a herniated disk and hypertrophy of the ligamentum flavum. Less common causes include arteriovenous malformations Spinal Cord Arteriovenous Malformations (AVMs) Arteriovenous malformations (AVMs) in or around the spinal cord can cause cord compression, ischemia, parenchymal hemorrhage, subarachnoid hemorrhage, or a combination. Symptoms may include... read more and slow-growing extramedullary tumors.
Atlantoaxial subluxation Atlantoaxial Subluxation Atlantoaxial subluxation is misalignment of the 1st and 2nd cervical vertebrae, which may occur only with neck flexion. (See also Evaluation of Neck and Back Pain and Craniocervical Junction... read more and other craniocervical junction abnormalities Craniocervical Junction Abnormalities Craniocervical junction abnormalities are congenital or acquired abnormalities of the occipital bone, foramen magnum, or first two cervical vertebrae that decrease the space for the lower brain... read more may cause acute, subacute, or chronic spinal cord compression.
Lesions that compress the spinal cord may also compress nerve roots or, rarely, occlude the spinal cord’s blood supply, causing spinal cord infarction Spinal Cord Infarction Spinal cord infarction usually results from ischemia originating in an extravertebral artery. Symptoms include sudden and severe back pain, followed immediately by rapidly progressive bilateral... read more .
Symptoms and Signs of Spinal Cord Compression
Acute or advanced spinal cord compression causes segmental deficits, paraparesis or quadriparesis, hyporeflexia (when acute) followed by hyperreflexia, extensor plantar responses, loss of sphincter tone (with bowel and bladder dysfunction), and sensory deficits. Subacute or chronic compression may begin with local back pain, often radiating down the distribution of a nerve root (radicular pain), and sometimes hyperreflexia and loss of sensation. Sensory loss may begin in the sacral segments. Complete loss of function may follow suddenly and unpredictably, possibly resulting from secondary spinal cord infarction.
Spinal percussion tenderness is prominent if the cause is metastatic carcinoma, abscess, or hematoma.
Intramedullary lesions tend to cause poorly localized burning pain rather than radicular pain and to spare sensation in sacral dermatomes. These lesions usually result in spastic paresis.
Diagnosis of Spinal Cord Compression
MRI or CT myelography
Spinal cord compression is suggested by spinal or radicular pain with reflex, motor, or sensory deficits, particularly at a segmental level.
Pearls & Pitfalls
MRI is done immediately if available. If MRI is unavailable, CT myelography is done; a small amount of iohexol (a nonionic, low osmolar radiopaque agent) is introduced via a lumbar puncture and allowed to run cranially to check for complete block of the cerebrospinal fluid (CSF). If a block is detected, a radiopaque agent is introduced via a cervical puncture to determine the rostral extension of the block. If traumatic bone abnormalities (eg, fracture, dislocation, subluxation) that require immediate spinal immobilization are suspected, plain spinal x-rays can be done. However, CT detects bone abnormalities better.
Treatment of Spinal Cord Compression
Relief of compression
Treatment of spinal cord compression is directed at relieving pressure on the cord. Incomplete or very recent complete loss of function may be reversible, but complete loss of function rarely is; thus, for acute compression, diagnosis and treatment must occur immediately.
If compression is due to a tumor, IV dexamethasone 100 mg is given immediately, followed by 25 mg every 6 hours and immediate surgery or radiation therapy.
Surgery is indicated in the following cases:
Neurologic deficits worsen despite nonsurgical treatment.
A biopsy is needed.
The spine is unstable.
Tumors recur after radiation therapy.
An abscess or a subdural or epidural hematoma that is compressing the spinal cord
Spinal cord compression is usually secondary to an extrinsic mass.
Manifestations may include back and radicular pain (early) and segmental sensory and/or motor deficits, altered reflexes, extensor plantar responses, and loss of sphincter tone (with bowel and bladder dysfunction).
Do MRI or CT myelography immediately.
To relieve pressure on the cord, do surgery or give corticosteroids as soon as possible.