What is spinal cord injury?
Spinal cord injury (SCI) is damage to the nerves within the spinal canal. Most SCI's 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 is the major bundle of nerves that carry nerve impulses to and from the brain to the rest of the body. These nerve impulses are the starting place for all our movements – the ones we have to think about (like walking or touching) and the ones that happen automatically (like breathing). The brain and the spinal cord make up the Central Nervous System. Motor and sensory nerves outside the central nervous system make up the Peripheral Nervous System; other systems that control involuntary functions (like blood pressure and temperature) are called the Sympathetic and Parasympathetic Nervous Systems.
There are two types of spinal cord injuries: complete and partial. In a complete injury, there is no no function below the level of the injury. Voluntary movement is impossible and physical sensationis impossible. Complete injuries are always bilateral, that is, both sides of the body are affected equally. A person with an incomplete injury retains some sensation below the level of the injury. Incomplete injuries are variable, and a person with such an injury may be able to move one limb more than another, 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 nerves enter and exit the spinal cord through the small openings between each vertebra. The nerves that enter through the tailbone (coccyx) are called coccygeal nerves. Spinal cord injuries occur most often in the areas of C5 to C7, and T10 to L2, where the spine is most flexible. When injured, each spinal area has distinct symptoms that help doctors pinpoint the nerves that are damaged.