Causes

Spinal cord injuries can result from damage to the vertebrae, ligaments or disks of the spinal column or to the spinal cord itself.

A traumatic spinal cord injury can stem from a sudden, traumatic blow to your spine that fractures, dislocates, crushes or compresses one or more of your vertebrae. It can also result from a gunshot or knife wound that penetrates and cuts your spinal cord.

Additional damage usually occurs over days or weeks because of bleeding, swelling, inflammation and fluid accumulation in and around your spinal cord.

A nontraumatic spinal cord injury can be caused by arthritis, cancer, inflammation, infections or disk degeneration of the spine.

Your brain and central nervous system

The central nervous system comprises the brain and spinal cord. The spinal cord is made of soft tissue and surrounded by bones (vertebrae). It extends down from the base of your brain and contains nerve cells and groups of nerves called tracts, which go to different parts of your body.

The lower end of your spinal cord stops a little above your waist in the region called the conus medullaris. Below this region is a group of nerve roots called the cauda equina.

Tracts in your spinal cord carry messages between your brain and the rest of your body. Motor tracts carry signals from your brain to control muscle movement. Sensory tracts carry signals from body parts to your brain relating to heat, cold, pressure, pain and the position of your limbs.

Damage to nerve fibers

Whether the cause is traumatic or nontraumatic, the damage affects the nerve fibers passing through the injured area and can impair part of or all the muscles and nerves below the injury site.

A chest (thoracic) or lower back (lumbar) injury can affect your torso, legs, bowel and bladder control, and sexual function. A neck (cervical) injury affects the same areas in addition to affecting movements of your arms and, possibly, your ability to breathe.

Common causes of spinal cord injuries

The most common causes of spinal cord injuries in the United States are:

• Motor vehicle accidents. Auto and motorcycle accidents are the leading cause of spinal cord injuries, accounting for almost half of new spinal cord injuries each year.
• Falls. A spinal cord injury after age 65 is most often caused by a fall.
• Acts of violence. About 12% of spinal cord injuries result from violent encounters, usually from gunshot wounds. Knife wounds also are common.
• Sports and recreation injuries. Athletic activities, such as impact sports and diving in shallow water, cause about 10% of spinal cord injuries.
• Diseases. Cancer, arthritis, osteoporosis and inflammation of the spinal cord also can cause spinal cord injuries.