Injuries may affect the spinal cord or the roots of the spinal nerves, which pass through the spaces between the back bones (vertebrae) of the spine. The bundle of nerves that extend downward from the spinal cord (cauda equina) may also be injured. Injuries of the spinal cord include the following:
Because the spinal cord is surrounded and protected by the spine, injuries of the spine or its connective tissue (such as disks and ligaments—see Low Back and Neck Pain: A Herniated Disk) can also injure the spinal cord. Such injuries include the following:
Attachments may be loosened so much that the vertebrae move freely. These injuries are considered unstable. When vertebrae move, they can compress the spinal cord or its blood supply and damage spinal nerve roots.
Most spinal cord injuries occur in motor vehicle accidents. Other causes include falls, sports, work-related accidents, and violence (such as a knife or gunshot wound).
If the spinal cord is injured, the nerves at and below the site of the injury malfunction, causing loss of muscle control and loss of sensation.
Loss of muscle control or sensation may be temporary or permanent, partial or total, depending on the severity of the injury. An injury that severs the cord or destroys nerve pathways in the spinal cord causes permanent loss, but a blunt injury that jars the cord may cause temporary loss, which can last days, weeks, or months. Sometimes swelling causes symptoms that suggest an injury more severe than it is, but the symptoms usually lessen as the swelling subsides.
Partial loss of muscle control results in muscle weakness. Paralysis usually refers to complete loss. When muscles are paralyzed, they often go limp (flaccid), losing their tone. But when the spinal cord is injured, paralysis may progress weeks later to involuntary, prolonged muscle spasms (called spastic paralysis).
If the spine is injured, people usually feel pain in the neck or back. The area over the injury may be tender to the touch. For people who are weak or paralyzed, movement is limited or impossible. Consequently, they are at risk of developing blood clots, pressure sores, permanently shortened muscles (contractures), urinary tract infections, and pneumonia.
Spinal cord injuries are best diagnosed with magnetic resonance imaging (MRI). Computed tomography (CT) is an alternative.
Injuries of the spine (affecting bone) are diagnosed most accurately with CT. However, x-rays are sometimes done first because they may be more readily available than CT.
Recovery is more likely if paralysis is partial and if movement or sensation starts to return during the first week after the injury. If function is not regained within 6 months, loss is likely to be permanent.
People who may have a spinal cord injury should not be moved except by emergency personnel. The first goals are to make sure people can breathe and to prevent further damage. Thus, emergency personnel take great care when moving a person with a possible spinal cord injury. Usually, the person is strapped to a firm board and carefully padded to prevent movement. A rigid collar may be used to keep the neck from moving. When the spine is severely damaged, the vertebrae may no longer be held in place or may be broken, making the spine unstable. Thus, even slight movement of the injured person can cause the spine to shift, putting pressure on the spinal cord. Pressure on the cord increases the risk of permanent paralysis.
Surgery is needed to remove blood and bone fragments if they have accumulated around the spinal cord. If the spine is unstable, people are kept immobile until the bone and other tissues have had time to heal. Sometimes a surgeon implants steel rods to stabilize the spine so that it cannot move and cause additional injury. If an injury causes only partial loss of function, surgery done soon after the injury may enable people to recover more function and become mobile sooner. However, the best time for surgery is debated. Spinal surgery may be done by neurosurgeons or orthopedic surgeons.
Drugs may be useful.
Experimental treatments to stimulate growth of spinal nerves are being studied. For example, a certain type of white blood cell (macrophage) can be extracted from, then injected into the injured person. Experimental drugs can be injected into the space around the spinal cord (epidurally) or taken by mouth. Using stem cells is another possibility, but this treatment requires much more study.
Rehabilitation, including physical and occupational therapy, can help people recover more quickly or more completely (see Rehabilitation: Spinal Injuries).
Last full review/revision August 2007 by Michael Rubin, MDCM