DISCOVERY Spinal cord injury involves damage to the nerves within the spinal canal; most SCIs are caused by trauma to the vertebral column, thereby affecting the spinal cord's ability to send and receive messages from the brain to the body's systems that control sensory, motor and autonomic function below the level of injury. The spinal cord and the brain together make up the central nervous system (CNS). The spinal cord coordinates the body's movement and sensation. The spinal cord includes neurons and long nerve fibers called axons. Axons in the spinal cord carry signals downward from the brain (along descending pathways) and upward toward the brain (along ascending pathways. The spinal cord is organized into segments along its length. Nerves from each segment connect to specific regions of the body. The segments in the neck, or cervical region, referred to as C1 through C8, control signals to the neck, arms, and hands. Those in the thoracic or upper back region (T1 through T12) relay signals to the torso and some parts of the arms. Those in the lumbar or mid-back region just below the ribs (L1 through L5) control signals to the hips and legs. Finally, the sacral segments (S1 through S5) lie just below the lumbar segments in the mid-back and control signals to the groin, toes, and some parts of the legs. The effects of spinal cord injury at different segments along the spine reflect this organization. Complete vs. Incomplete What is the difference between a "complete injury" and a "incomplete injury?" Persons with an incomplete injury have some spared sensory or motor function below the level of injury – the spinal cord was not totally damaged or disrupted. In a complete injury, nerve damage obstructs every signal coming from the brain to the body parts below the injury. While there's almost always hope of recovering function after a spinal cord injury, it is generally true that people with incomplete injuries have a better chance of getting some return. In a large study of all new spinal cord injuries in Colorado, reported by Craig Hospital, only one in seven of those who were completely paralyzed immediately after injury got a significant amount of movement back. But, of those who still had some movement in their legs immediately after injury, three out of four got significantly better. About 2/3 of those with neck injuries who can feel the sharpness of a pin-stick in their legs eventually get enough muscle strength to be able to walk. Of those with neck injuries who can only feel light touch, about 1 in 8 may eventually walk. The sooner muscles start working again, the better the chances are of additional recovery. But when muscles come back later - after the first several weeks - they are more likely to be in the arms than in the legs. As long as there is some improvement and additional muscles recovering function, the chances are better that more improvement is possible. The longer there is no improvement, the lower the odds it will start to happen on its own. Currently, there is no cure for spinal cord injuries. However, ongoing research to test surgical and drug therapies is progressing rapidly. Injury progression prevention drug treatments, decompression surgery, nerve cell transplantation, nerve regeneration, and complex drug therapies are all being examined as a means to overcome the effects of spinal cord injury. LIFETIME COSTS The average yearly health care and living expenses and the estimated lifetime costs that are directly attributable to SCI vary greatly according to severity of injury. These figures do not include any indirect costs such as losses in wages, fringe benefits and productivity which average $59,212 per year in March 2006 dollars, but vary substantially based on education, severity of injury and pre-injury employment history. Average Yearly Expenses (in May 2006 dollars) Severity of Injury First Year Each Subsequent Year High Tetraplegia (C1-C4) $741,425 $132,807 Low Tetraplegia (C5-C8) $478,782 $54,400 Paraplegia $270,913 $27,568 Incomplete Motor Functional $218,504 $15,313 Estimated lifetime costs by Age at Injury (discounted at 2%) Severity of Injury 25 years old 50 years old High Tetraplegia (C1-C4) $2,924,513 $1,721,677 Low Tetraplegia (C5-C8) $1,653,607 $1,047,189 Paraplegia $977,142 $666,473 Incomplete Motor Functional $651,827 $472,392