Traumatic spinal cord injury is when an external force strikes the spinal column. It fractures or shifts the vertebrae, causing compression of the spinal cord.
Over time, the damage to your spinal cord can amplify because traumatic spinal cord injury has 2 stages: primary and secondary.
Primary Traumatic Spinal Cord Injury
Primary traumatic spinal cord injury is the initial blow to the spinal cord.
Examples of traumatic spinal cord injury causes include car crashes, falls, violence, and sports accidents.
The compression leads to:
- cell damage and death
- blood vessel damage
- misalignment of the spine
- strained nerves
- reduced blood supply
Secondary Traumatic Spinal Cord Injury
The secondary stage of traumatic spinal cord injury is a result of the changes your spinal cord undergoes in the hours to weeks following the injury.
Essentially, your body goes into defense mode and activates the release of a bunch of chemicals to stabilize the spinal cord.
Unfortunately, these processes end up doing more harm than good and amplify spinal cord damage by reducing blood flow, increasing inflammation, overexciting the neurons, and inhibiting axon regrowth.
Reduced Blood Flow
Damaged blood vessels lead to reduced blood supply and hemorrhaging. Without sufficient blood pressure, your cells don’t get enough oxygen and nutrients, causing them to die.
This can cause swelling of the spinal cord, which can cut off blood flow and lead to spinal shock.
Spinal shock is a temporary loss of feeling, movement, and reflexes. It can last anywhere from a few days to several weeks,
When swelling improves, these functions can gradually return depending on the severity of your traumatic spinal cord injury.
Normally, your blood-brain barrier helps regulate the entry of immune cells into spinal cord tissues. In the case of a traumatic spinal cord injury, the barrier gets disrupted and immune cells invade the spinal cord.
They activate an inflammatory response that intensifies the hostile microenvironment and cause even more cell deaths.
Another harmful outcome of inflammation is the production of free radicals. Free radicals are highly reactive molecules that cause cell damage through a process called oxidative stress.
In small quantities, they are not harmful. However, after traumatic spinal cord injury, they are produced in large amounts which destroys the interior lining of your blood vessels and your cell tissues.
Excessive Release of Neurotransmitters
Another source of damage comes from the excessive release of neurotransmitters (the chemicals that allow neurons to communicate with each other).
When too many neurotransmitters are released, the neurons in your spinal cord get overstimulated and damaged in a process called excitotoxicity.
Cystic Cavities and Glial Scarring
So why can’t the spinal cord regenerate as easily as other parts of the body?
Cystic cavities form at the site of injury as a result of the mass amount of cell deaths.
They don’t particularly serve any function and are essentially voids that take up space and inhibit the growth of axons.
Additionally, glial scars form around the cyst. They create a barrier that separates the injured area from the rest of the spinal cord to prevent further damage.
However, glial scars aren’t penetrable, so they also prevent neural regeneration.
Traumatic Spinal Cord Injury Treatment
Traumatic spinal cord injury should be evaluated as soon as possible to reduce the effect of secondary injuries.
Immediate treatment goals for traumatic spinal cord injury include:
- decreasing inflammation
- increasing blood flow
- preventing glial scar/ cystic cavity formation
- decelerating cell deaths.
After stabilizing the injury, treatment goals focus more on recovering sensorimotor functions.
Although treatments for traumatic spinal cord injury have yet to be fully developed, clinical trials are showing very promising results.
Clinical stem cell trials prove most effective in earlier phases of traumatic spinal cord injury, prior to scar or cavity formation.
A study on rats with spinal cord injury showed that stem cell transplants from bone marrows and umbilical cords helped prevent cystic cavity formation and increased functional recovery.
Axon regrowth was possible because no cavities or scarring blocked the neural pathways.