In this article, I am endeavoring to present a concise, but descriptive definition of spinal cord injury useful to the general person. Often times, literature is written by medical practitioners for their colleagues, and includes language and concepts foreign to those who are not involved in the professional clinical setting. Hopefully, this article will break that barrier and be especially useful for those who suddenly find themselves confronted with a spinal cord injury and are searching for informative content. I have underlined key terms that are useful to know when speaking with medical professionals.
To date, there are a quarter of a million Americans who have suffered a spinal cord injury and twelve thousand newly injured every year, (I would present world statistics, but they tend to be rough estimates on a global scale.) Spinal cord injury is often abbreviated as the acronym SCI. It is not like many diseases which advance in gradual onset, but is the result of a sudden split second accident. In this traumatic accident, an unprepared victim’s and their family’s lives are immediately and drastically changed.
In order to understand the nature of a SCI, it is important to get a basic idea of the anatomy involved, especially concerning the spine. The human spine is composed of bones, nerves, and blood vessels; every part holding a vital role The bones of the spine are each called vertebra (plural vertebrae) and are ‘stacked’ on top of one another with a cushioning disc between each one. There are twenty four vertebrae, each able to move slightly at the disc, allowing the whole back to bend. The first seven vertebrae from the neck down are referred to as “cervical”. The next twelve compose the mid-back and are known as the “thoracic” vertebrae. There are five “lumbar” vertebrae below the thoracic, and finally five “sacral” vertebrae which are fused in adults. Below the sacral are four small “coccygeal” vertebrae which compose the tail bone. The total 24 vertebrae form a “vertebral column,” a hollow tube of bone through which runs the spinal cord and blood vessels which support it.
The spinal cord is essentially an information link from the brain to the body. Sensations, (such as pain and touch) are sent up and signals for actions are sent back down. Smaller bundles of nerves (called “peripheral”) exit the spinal cord at each vertebrae and direct the signals to muscles. Trauma to the spine can break or even shatter vertebrae, damage surrounding tissues, or cause direct injury to the spinal cord itself. Common traumas that lead to SCI include; vehicle crashes, falls, impact blows from sports and recreation, diving, and gunshots or pierce wounds. Twisting the back unnaturally in an accident can pull stretch, or compress the spinal cord causing permanent damage. The spinal cord itself can be thought of similar to a banana; it bruises very easily. Within the spinal cord are not just long nerve cells (called neurons), but also many other cells that are essential for its function. Once the complex architecture of the spinal cord is damaged, it has very limited ability to rebuild and heal itself.
Results of a SCI can vary extensively depending on the level of damage and location in the spine. Spinal cord injuries which happen near the neck (cervical) affect everything which branches off below. If the SCI occurs farther down the back, everything which branches off above the injury site will remain intact. For example, I broke my T12 vertebra (the twelfth “thoracic” vertebra) in a skiing accident. My injury has no effect on my arms, abdominal (stomach) muscles, or my upper torso because the peripheral nerves traveling to these locations branch off from the spinal cord before T12. Yet, my hamstrings, calves, and ankles are affected by my injury because the nerves in the spinal cord leading to these locations are below the injury site and the “connection wire” was damaged.
A quadriplegic is a person whose spinal cord injury has resulted in a decrease in normal function in all four limbs (“quad” means four). Quadriplegia typically results from injuring the spinal cord at the neck (cervical) level. A paraplegic refers to one who has lost function in the legs, commonly resulting from an SCI to the upper-lower back (thoracic-lumbar). A common misconception is that quadriplegia and paraplegia mean a complete paralysis, but this is not the case. It simply means a loss of normal function, a disability
Spinal cord injuries are classified into two broad categories which help to explain the symptoms and nature of injury to the cord itself. Complete spinal cord injuries are the result of the complete severing of the spinal cord, as if it has been completely cut through by a knife into two pieces. None or very few signals from the brain are passing through the injury site. The result is complete loss of any functions which branch off below the injury site, causing immediate and complete paralysis.
Incomplete spinal cord injuries result when the spinal cord is not completely cut through, or is bruised by a blow or compacted bone. Some nerve messages have the ability to pass through the injury site, while others are permanently damaged. The resulting symptoms vary extensively. Often when an incomplete SCI occurs, the spinal cord swells and all signals are temporarily unable to travel back and forth from the brain. Over months, this swelling very slowly reduces and signals are once again able to travel to the brain. For example, immediately when I was injured I was paralyzed from the waist down for two months due to my the compression on my spine causing swelling. After this initial two months, very gradually, I regained some muscle control in my lower limbs so that now I am able to functionally walk. The permanent nerve damage is still present in paralysis in lower leg muscles and general weakness in the hamstrings.
The majority of SCI require surgery, hospitalization, and extensive therapy. There are two major fields of therapy which are necessary to begin a fruitful life, though physical abilities have changed. Occupational therapy involves learning how to function with a disability. This may involve how to utilize a wheelchair, optimize your home for your needs, or to even dress yourself in the morning if you are now paralyzed. Occupational therapy teaches you the functional skills required in order to live optimally. Physical therapy involves improving your physical condition through key exercise programs. When paralyzed, muscles decrease in strength (atrophy) and tighten very quickly. Physical therapy aims to stretch tight muscles and strengthen them. Even if a person is paralyzed, physical therapy training is key to keep the body active and healthy. For incomplete SCI, intense physical therapy works to retrain muscle functions after they emerge from paralysis.
Spinal cord injuries are serious and can involve many complications. With paralysis and injury to the spinal cord comes a decrease or absent sensation of pain/pressure. A very common preventable condition associated with SCI is a form of skin breakdown called pressure sores. These sores result simply when a person lies, sits, or applies significant pressure to one section of skin for too long. A paralyzed individual is unable to sense the pain or pressure from such long durations. If left untreated, the skin under pressure can break down and lead to a open wound, easily infected. Therefore it is critically important for individuals with SCI to make conscious observations and decisions in order to protect their skin.
Paralysis from SCI can cause several internal organ issues that must be closely watched. Depending on the extent of an individual injury, decreased bowel, bladder, and sexual function can occur. Utilizing a catheter to assist in urination can lead to a bladder infection, which if left untreated can cause kidney malfunction. Therefore, it is important to practice proper medical sterile techniques, which can be learned by an individual from a medical professional. A severe SCI resulting from a neck (cervical) injury can affect breathing due to less control of the diaphragm. SCI individuals can have a condition known as autonomic hyperreflexia. Our bodies have both a voluntary (you can consciously control) and involuntary (example: heart rate) nervous system. In autonomic hyperreflexia, the involuntary nervous system is overstimulated and causes the body to go into “emergency mode,” raising blood pressure, causing a fever, lightheartedness, or fainting. A normal person’s body would react and respond properly to the stimulation, but a paralyzed individual’s body is unable to sense it until it is to late. Autonomic hyperreflexia can be life threatening and it is important for those with SCI to be aware of its symptoms and preventions. Many other complications involved in SCI include osteoporosis (bone loss from lack of use), deep vein thrombosis (dangerous blood clots in paralyzed limbs), and muscle spasticity (unused muscles tighten very strongly over time).
I hope this article has been helpful and useful to those who are facing a SCI or are seeking to learn. It is important to note that injuries to the neck and back are always serious. It is important to call 911 if there is any noticed loss of sensation or movement. A person suspected of having a spinal cord injury should not be moved until trained health professionals arrive because further damage can occur do to the shifting of the injury site.
National Spinal Cord Injury Statistical Center https://www.nscisc.uab.edu/public_content/pdf/Facts%202011%20Feb%20Final.pdf
Spine Universe http://www.spineuniverse.com/anatomy