Injuries and disorders can put pressure on the spinal cord, causing back pain, tingling, muscle weakness, and other symptoms.
The spinal cord may be compressed by bone, blood (hematomas), pus (abscesses), tumors (cancerous or not), or a ruptured or herniated disk.
Symptoms, such as back pain, abnormal sensations, muscle weakness, or impaired bladder and bowel control, may be mild or severe.
Doctors base the diagnosis on symptoms and the results of a physical examination, magnetic resonance imaging, or another imaging test.
Corticosteroids are often given to reduce swelling in or around the spinal cord and thus help reduce pressure on the spinal cord.
Depending on the cause, surgery and/or radiation therapy may be used to relieve the pressure.
Normally, the spinal cord is protected by the spine, but certain injuries and disorders may put pressure (compress) on the spinal cord, disrupting its normal function. These injuries and disorders may also compress the roots of spinal nerves, which pass through the spaces between the back bones (vertebrae), or the bundle of nerves that extend downward from the spinal cord (cauda equina).
The spinal cord may be compressed
- Suddenly, causing symptoms in minutes or over a few hours or days
- Slowly and gradually, causing symptoms that worsen over many weeks or months
The spinal cord may be compressed by the following:
- Bone: If the vertebrae are broken (fractured), are dislocated, or grow abnormally (as occurs in cervical spondylosis), they may compress the spinal cord. Vertebrae that are weakened by cancer or osteoporosis may break after a slight or even no injury.
- Connective tissue: Connective tissue that lines the spinal canal often enlarges and hardens as people age. This change narrows the spinal canal and compresses the spinal cord. (The spinal canal is the passageway that runs through the center of the spine and contains the spinal cord.)
- An accumulation of blood (hematoma): Blood may accumulate in or around the spinal cord. The most common cause of a spinal hematoma is an injury, but many other conditions can cause hematomas. They include abnormal connections between blood vessels (arteriovenous malformations), tumors, bleeding disorders, and use of anticoagulants (which interfere with blood clotting) or thrombolytic drugs (which break up blood clots).
- Tumors: Cancer that has spread (metastasized) to the spine or the space around the spinal cord is a common cause of compression. Rarely, a tumor within the spinal cord causes compression. The tumor may be cancerous or not.
- A pocket of pus (abscess): Pus may accumulate outside the spinal cord or, less commonly, in the spinal cord and may compress it.
- A ruptured or herniated disk: A herniated disk can compress spinal nerve roots (the part of spinal nerves next to the spinal cord) and occasionally the spinal cord itself.
Sudden compression typically results from:
- An injury (the most common cause), which often results in a fracture or dislocation of a vertebra
- Hematomas and ruptured disks
However, bones weakened gradually (for example, by cancer or osteoporosis) may suddenly fracture, which can suddenly cause or worsen compression (see Compression Fractures of the Spine).
Gradual compression can develop over days to years. Typical causes vary depending on how long it takes compression to develop:
- Days to weeks: Abscesses or tumors
- A few months: Some chronic infections (such as spinal tuberculosis), some slow-growing tumors, or cervical spondylosis (degeneration of vertebrae and disks in the neck—see Cervical Spondylosis)
- Many years: Usually, cervical spondylosis