A spinal cord injury is often caused by a traumatic event that fractures or dislocates vertebrae in the spine—resulting in a bruise, tear of spinal cord tissue or inflammation that compresses the spinal cord tissue. SCIs can also be caused by certain diseases such as polio, spina bifida, transverse myelitis, syringomyelia, Friedreich's ataxia and other causes.1
Spinal cord injuries are often referred to as either complete or incomplete. Some physiatrists discount these classifications as outdated. Even with a ‘complete’ classification, some function or sensation may remain intact or return post-injury. A complete injury means that there is likely to be no function, sensation or voluntary movement below the level of the injury. Both sides of the body are equally affected. An incomplete injury means that there is some function below the primary level of the injury. The extent of incompleteness may vary from slightly to very incomplete. A person with an incomplete injury may be able to move one limb more than another, may be able to feel parts of the body that can not be moved, or may have more functioning on one side of the body than the other.1
Trauma that completely severs the spinal cord is rare. In most cases trauma leads to fractures or compression of the vertebrae. This in turn can crush and destroy axons, which are extensions of nerve cells that carry signals up and down the spinal cord between the brain and the rest of the body.1