What are spinal cord injuries (SCI)?
Spinal cord injury is damage to the spinal cord that results in a loss of function such as mobility or feeling. Frequent causes of damage are trauma (car accident, falls, diving etc.) or disease (polio, spina bifida, Friedreich’s Ataxia etc.).
Quadriplegia (also referred to as tetraplagia) is loss of function below the neck.
Paraplegia is loss of function below the chest.
The spinal cord does not have to be severed in order for a loss of functioning to occur. In fact, in most people with spinal cord injury, the spinal cord is intact, but the damage due to compression or bruising to it results in loss of functioning. Spinal cord injury is very different from back injuries such as ruptured disks, spinal stenosis or pinched nerves.
A person can “break their back or neck” yet not sustain a spinal cord injury if only the bones around the spinal cord (the vertebrae) are damaged, but the spinal cord is not affected. In these situations, the individual may not experience paralysis if bone damage is treated correctly.
What is the spinal cord and the vertabrae?
The adult spinal cord is about 50 centimetres long and extends from the base of the brain to about the waist. It is the major bundle of nerves that carry messages between the brain and the rest of the body. Nerves within the spinal cord (upper motor neurons) carry messages back and forth from the brain to the spinal nerves along the spinal tract. Lower motor neurons branch out from the spinal cord to the other parts of the body, carrying sensations (from the skin and other body parts and organs to the brain) and instructions (to the various body parts to initiate actions such as muscle movement).
Injury to the spinal cord causes loss of function of the nerves, limbs and organs below the site of the injury.
The spinal cord lies within vertebrae. These rings of bones are together called the spinal column or back bone. In general, the higher in the spinal column an injury occurs, the more dysfunction a person will experience.
There are seven vertebrae in the neck—the Cervical Vertebrae—C1 (at the top) to C7. Injury in this region usually causes loss of function to the arms and legs (quadriplegia or tetraplegia).
There are twelve Thoracic Vertebrae. The highest (T1) is where the top rib attaches. Injury to the thoracic region affects the chest and the legs.
Between the thoracic vertebrae and the pelvis lie the 5 Lumbar Vertebrae. The 5 Sacral Vertebrae run from the pelvis to the end of the spinal column. Injury to nerves in the lumbar and sacral vertebrae generally results in loss of functioning in the hips and legs.
Loss of function in the chest, hips and legs is Paraplegia.
After spinal cord injury how much function can be restored?
At the time of injury, the spinal cord swells. As this swelling reduces, some function may return. This can take up to 18 months after the injury. However, only a very small fraction of people with a spinal cord injury recover all function.
Most body parts and organs can repair themselves after they are injured. However the central nervous system cannot. Attempting to repair the damage caused by a brain or spinal cord injury is a puzzle that has not yet been solved.
Nevertheless the damage caused by a spinal cord injury can be reduced by limiting immediate cell death and reducing the inflammation of the injured cord.
Attempts to regenerate function in the damaged area are focusing on regrowing nerves, blocking the mechanism that stop neurons from regrowing themselves, inserting new cells and bypassing the damaged area.
Intensive Activity Based exercise programs can assist in the improvement of independent functional abilities. Intensive exercise programs can:
- Increase muscle mass
- Increase muscle activity
- Increase blood circulation
- Improve sensation
- Prevent a decrease in bone mineral density
- Improve quality of life
- Increase independence in activities of daily living and occupational activities
- Decrease skin tissue breakdown and other health problems associated with spinal cord injury
(Spinal Cord Injuries Australia)