SPINAL CORD INJURY

Spinal cord injury causes myelopathy or damage to white matter or myelinated fiber tracts that carry sensation and motor signals to and from the brain. It also damages gray matter in the central part of the spinal cord, causing segmental losses of interneurons and motorneurons.

The exact effects of a spinal cord injury vary according to the type and level of injury, and can be organized into two types:
In a complete injury, there is no function below the "neurological" level, defined as the lowest level that has intact neurological function. If a person has some level below which there is no motor and sensory function, the injury is said to be "complete". Recent evidence suggest that less than 5% of people with "complete" spinal cord injury recover locomotion.
A person with an incomplete injury retains some sensation or movement below the level of the injury. The lowest spinal cord level is S4-5, representing the anal sphincter and peri-anal sensation. So, if a person is able to contract the anal sphincter voluntarily or is able to feel peri-anal pinprick or touch, the injury is said to be "incomplete". Recent evidence suggest that over 95% of people with "incomplete" spinal cord injury recover some locomotory ability.

Knowing the exact level of the injury on the spinal cord is important when predicting what parts of the body might be affected by paralysis and loss of function.