There are two types of spinal cord injuries: complete spinal cord injuries refer to a total loss of function below the level of the injury, while incomplete spinal cord injuries are those that result in a partial loss of function.
Complete Spinal Cord Injury
A complete spinal cord injury means that there is no movement or sensation below the level of the injury. In a complete injury, both sides of the body are equally affected; the result is either complete paraplegia, total paralysis in two limbs, or complete tetraplegia, total paralysis in all four limbs (also called quadriplegia).
Complete paraplegia is the permanent loss of motor and nerve function at the T1 level or below; the result is loss of sensation, movement, and/or control in the legs, bowel, bladder, and sexual region, however, arms and hands retain normal function.
Complete tetraplegia is the permanent loss of movement and sensation at the C1 to C8 levels; the result is loss of function in all four limbs and in some cases, tetraplegics require ventilator systems in order to breathe. The degree of retained functionality depends on where the injury to the spine occurred.
Incomplete Spinal Cord Injury
Incomplete spinal cord injuries are more common than complete injuries and are characterized by some movement or sensation below the point of injury. A person suffering from an incomplete spinal cord injury can often move one limb more than another, may have more function on one side than the other, or might have some sensation in parts of the body, but unable to move those parts. The effects of an incomplete injury are dependent upon whether the front (anterior cord syndrome), back (posterior cord syndrome), side (brown-sequard syndrome), or center (central cord syndrome) of the spinal cord was affected.