July 25, 2016 | 8:00 am | By Pants Up Easy
You’re probably aware of how traumatic of an event a spinal cord injury can be. But you may not really understand the different levels of spinal cord injuries and the resulting effects. For example there are different levels of paralysis. In order to understand what these are, and the differences between paraplegia, quadriplegia, “T9 Complete”, and so on, we need to understand a little more about how the spinal cord works, and what happens with a spinal cord injury.
The spine is an assembly of rings of bone, known as vertebrae, stacked vertically. The spinal cord, however, is the collection of nerves which run up and down the length of the spine. Together with the brain, it’s a part of the Central Nervous System. The spinal cord is actually the connection that allows the brain to talk to the rest of the body. Signals from the brain to the body instruct it to move, and that includes both voluntary functions like raising your arm or walking, and involuntary, automatic functions like heartbeat and digestion. The body in turn sends sensory information through the spinal cord, informing the brain of sensations in various body parts.
As the spinal cord is the main trunk of information flow from the brain to the body, any injury that interrupts that flow is going to cause some serious consequences. What those effects are, and what body parts are impacted, depends on the severity and the location of the injury. If the nerve tissue is wounded, but not broken, paralysis may not occur. But if the nerves of the spinal cord are severed, paralysis or loss of sensation may occur in areas located below the level of the injury.
If the damage to the spinal cord results in one’s legs becoming paralyzed, the condition is known as paraplegia. In the case of an injury located higher up on the spinal cord, all four limbs may be paralyzed, resulting in what is known as quadriplegia.
To discuss SCI properly, it will help to look at a diagram of the nerves that make up the spinal cord. The nerves are grouped into four categories, identified by the letter in their names: C (cervical), T (thoracic), L (lumbar), or S (sacral). Within each group, there is a numbered sequence of nerves. So T9 is the ninth thoracic nerve, part of the group of nerves which connect the brain to the torso and some parts of the arms. Above T9 are T1 through T8, which control the upper torso. Injuries to that area are likely to limit trunk movement and abdominal control. T9 injuries, on the other hand, tend to leave the patient with good control of their trunk and abdominal muscles, while unfortunately eliminating control of the legs.
The use of the term “T9 complete” is really just an indication of how complete the loss is. There are “incomplete” cases, in which feeling or movement has not completely been lost. In a T9 complete case, however, one can expect that while loss of the legs is complete, the patient still has enough trunk and abdominal control so that balance is usually good, and functional independence remains a real possibility.