1.2. The spinal cord after injury
Damage to the spinal cord can occur from either a traumatic injury or from a disease to the vertebral column. In most spinal cord injuries, the backbone pinches the spinal cord, causing it to become bruised or swollen. Sometimes the injury may tear the spinal cord and/or its nerve fibers. An infection or a disease can result in similar damage. After a spinal cord injury, all the nerves above the level of injury keep working like they always have. From the point of injury and below, the spinal cord nerves cannot send messages between the brain and parts of the body like they did before the injury.
The doctor examines the individual to understand what damage has been done to the spinal cord. An X-ray shows where the damage occurred to the vertebrae. The doctor does a "pin prick" test to see what feeling the person has all over his body (sensory level). The doctor also asks, "what parts of the body can you move?" and tests the strength of key muscle groups (motor level). These exams are important because they tell what nerves and muscles are working.
A person's injury is described by its level and type. The level of injury for a person with SCI is the lowest point on the spinal cord below which there is a decrease or absence of feeling (the sensory level) and/or movement (the motor level).
Tetraplegia [formerly called quadriplegia] generally describes the condition of a person with a spinal cord injury that is at a level from C1 to T1. This individual can experience a loss of feeling and/or movement in their head, neck, shoulder, arms and/or upper chest.
Paraplegia is the general term describing the condition of a person who has lost feeling and/or is not able to move the lower parts of his/her body. The body parts that may be affected are the chest, stomach, hips, legs and feet. An individual with a level from T2 to S5 has paraplegia.
The higher the spinal cord injury is on the vertebral column, or the closer it is to the brain, the more effect it has on how the body moves and what one can feel. More movement, feeling and voluntary control of the body's systems are present with a lower level of injury. For example, a person with a C-5 level of injury has a decrease or loss of feeling and movement below the 5th cervical spinal cord segment. An injury at the T-8 level means the individual has a decrease or loss of feeling and movement below the eighth thoracic spinal cord segment. Someone with a T-8 level of injury would have more feeling and movement than someone with a C-5 level of injury.
Complete or Incomplete Injury
The amount of feeling and movement that an individual has also depends on whether the injury is complete or incomplete. A complete injury means there is no motor or sensory function in the S4 or S5 area, or anal area. If there is evidence of any motor or sensory function in this area, one of three incomplete injury classifications is given. Some people with an incomplete injury may have feeling, but little or no movement. Others may have movement and little or no feeling. Incomplete spinal injuries differ from one person to another because the amount of damage to each person's nerve fibers is different. This fact makes it impossible to accurately predict how much of an individual's sensory and motor function will return. There is a greater chance of return of some or all of a person's motor and sensory function if an individual is incomplete at the time of injury.
Changes after the Initial Injury
Sometimes the spinal cord is only bruised or swollen after the initial injury. As the swelling goes down, the nerves may begin to work again. There are no tests at this time to tell how many nerves, if any, will begin to work again or when this will occur. Some individuals have involuntary movements, such as twitching or shaking. These movements are called spasms. Spasms are not a sign of recovery. A spasm occurs when a wrong message from the nerve causes the muscle to move. The individual often cannot control this movement. In addition to movement and feeling, a spinal cord injury affects how other systems of the body works.
During rehabilitation, a medical team will assist you in learning new ways to manage your daily activities and stay healthy.