The Spinal Cord

A spinal cord is the pathway that processes impulses from the body to the brain, and from the brain to the body. The impulses sent by the spinal cord are different signals our brain sends and receives from our bodies.

Spinal cord injuries (SCIs) are usually caused by a sudden, traumatic blow to the spine that dislocates or fractures vertebrae. The most common causes of SCIs are trauma, such as car accidents, falls or even gunshot wounds. Certain diseases can also result in SCI.

The effects of an SCI can depend on the type of injury and the level of the injury sustained. An SCI can be divided into two types of injury - complete and incomplete.

A complete SCI injury means that there is no function below the level of the injury. That means no sensation and no voluntary movement and both sides of the body are equally affected. An incomplete injury means that there is some functioning below the primary level of the injury. A person with an incomplete injury may be able to move one limb more than another, and may be able to feel parts of the body that cannot be moved, or may have more functioning on one side of the body than the other.

The level of injury is very helpful in predicting what parts of the body might be affected by paralysis and loss of function. In incomplete injuries there will probably be some variation in these prognoses.

The area the SCI occurs is also crucial. SCIs are classified according to the area on the spine where they occur. For example, injuries above the C-4 level may require a ventilator for the person to breathe. C-5 injuries often result in shoulder and biceps control, but no control at the wrist or hand. C-6 injuries generally yield wrist control, but no hand function. Individuals with C-7 and T-1 injuries can straighten their arms but still may have dexterity problems with the hand and fingers. Injuries at the thoracic level and below result in paraplegia, with the hands not affected. At T-1 to T-8 there is most often control of the hands, but poor trunk control as the result of lack of abdominal muscle control. Lower T-injuries (T-9 to T-12) allow good truck control and good abdominal muscle control. Sitting balance is very good. Lumbar and Sacral injuries yield decreasing control of the hip flexors and legs.

Besides a loss of sensation or motor functioning, individuals with SCI also experience other changes. For example, they may experience dysfunction of the bowel and bladder. Sexual functioning is frequently a problem with SCI and many male sufferers may have their fertility affected, while women's fertility is generally not affected. Very high injuries (C-1, C-2) can result in a loss of many involuntary functions including the ability to breathe, necessitating breathing aids such as mechanical ventilators or diaphragmatic pacemakers. Other effects of SCI may include low blood pressure, inability to regulate blood pressure effectively, reduced control of body temperature, inability to sweat below the level of injury, and chronic pain

Approximately 450,000 people live with SCI in the US. There are about 10,000 new SCIs every year, with the majority of them involving males between the ages of 16-30. Thousands of personal injury lawsuits are filed yearly as a result of SCIs.