Spinal Cord Injury is an injury to the spinal cord that results in paralysis and loss of sensation. It causes myelopathy or damage to white matter or myelinated fiber tracts that carry signals to and from the brain. Also, it could damage the gray matter in the central part of the cord, triggering segmental losses of interneurons and motorneurons.
Clinical Manifestations
Spinal cord injuries are classified as either complete or incomplete. An incomplete injury means that the ability of the spinal cord to convey messages to or from the brain is not completely lost. People with incomplete injuries retain some motor or sensory function below the injury. A complete injury is indicated by a total lack of sensory and motor function below the level of injury. People who survive a spinal cord injury will most likely have medical complications such as chronic pain and bladder and bowel dysfunction, along with an increased susceptibility to respiratory and heart problems. Successful recovery depends upon how well these chronic conditions are handled day to day.
How Does a Spinal Cord Injury Affect the Rest of the Body?
People suffering from a spinal cord injury will likely have medical complications such as chronic pain, bladder and bowel dysfunction as well as an increased susceptibility to respiratory and heart problems.
Breathing
Any injury of the spinal cord at or above the C3, C4, and C5 segments, which supply the phrenic nerves causing the diaphragm, could stop breathing. People with these injuries need immediate ventilatory support. If the injuries are at the C5 level and below, the sufferers' diaphragm function is reserved, but breathing is apt to be rapid and shallow and people have trouble coughing and clearing secretions from their lungs due to weak thoracic muscles.
Pneumonia
Respiratory complications, primarily as a result of pneumonia, are a leading cause of death in the patients with spinal cord injury. As a matter of fact, intubation increases the risk of developing ventilator-associated pneumonia (VAP) by 1-3 percent per day. More than 15% of the deaths caused by spinal cord injury are the result of VAP.
Irregular heart beat and low blood pressure
Patients suffering from spinal cord injuries in the cervical region are often accompanied by blood pressure instability and heart arrhythmias. Due to the interruptions to the cardiac accelerator nerves, the heart can beat at a dangerously slow pace, or it can pound rapidly and irregularly. Arrhythmias usually appear in the first 2 weeks after injury and are more common and severe in the most serious injuries. Low blood pressure also often occurs due to loss of tone in blood vessels, which widen and cause blood to pool in the small arteries far away from the heart.
Spasm
As many of our reflex movements are controlled by the spinal cord but regulated by the brain, when the spinal cord is damaged, information from the brain can no longer regulate reflex activity. Reflexes may become exaggerated over time, causing spasticity. If spasms become severe enough, they may require medical treatment. For some, spasms can be as much of a help as they are a hindrance, since spasms can tone muscles that would otherwise waste away. Some people can even learn to use the increased tone in their legs to help them turn over in bed, propel them into and out of a wheelchair, or stand.
Autonomic dysreflexia
Autonomic dysreflexia is a life-threatening reflex action that primarily affects those with injuries to the neck or upper back. It happens when there is an irritation, pain, or stimulus to the nervous system below the level of injury. The irritated area tries to send a signal to the brain, but since the signal isn't able to get through, a reflex action occurs without the brain's regulation. Unlike spasms that affect muscles, autonomic dysreflexia affects vascular and organ systems controlled by the sympathetic nervous system.
Pressure sores
Pressure sores are areas of skin tissue that have broken down because of continuous pressure on the skin. People with paraplegia and quadriplegia are susceptible to pressure sores because they can't move easily on their own.
Pain
People who are paralyzed often have what is called neurogenic pain resulting from damage to nerves in the spinal cord. For some survivors of spinal cord injury, pain or an intense burning or stinging sensation is unremitting due to hypersensitivity in some parts of the body. Others are prone to normal musculoskeletal pain as well, such as shoulder pain due to overuse of the shoulder joint from pushing a wheelchair and using the arms for transfers. Treatments for chronic pain include medications, acupuncture, spinal or brain electrical stimulation, and surgery.
Bladder and bowel problems
Most spinal cord injuries affect bladder and bowel functions because the nerves that control the involved organs originate in the segments near the lower termination of the spinal cord and are cut off from brain input. Without coordination from the brain, the muscles of the bladder and urethra can't work together effectively, and urination becomes abnormal. The bladder can empty suddenly without warning, or become over-full without releasing. In some cases the bladder releases, but urine backs up into the kidneys because it isn't able to get past the urethral sphincter. Most people with spinal cord injuries use either intermittent catheterization or an indwelling catheter to empty their bladders.
Reproductive and sexual function
Spinal cord injury has a greater impact on sexual and reproductive function in men than it does in women. Most spinal cord injured women remain fertile and can conceive and bear children. Even those with severe injury may well retain orgasmic function, although many lose some if not all of their ability to reach satisfaction. Depending on the level of injury, men may have problems with erections and ejaculation, and most will have compromised fertility due to decreased motility of their sperm.
Neural Stem Cell Transplantation Treatment for SCI
Considering their characteristic abilities to self-renew and differentiate into neurons, oligodendrocytes and astrocytes in the body, the therapeutic promise of neural stem cells is justied, and many clinical cases have proved that neural stem cells could be used for replacement of neural cell loss for spinal cord injury. Neurons can survive and integrate after injection in the patient's body. Oligodendrocytes were able to myelinate axons, which was a compensation for the demyelination caused in the spinal cord injury.
