Definition: Defining the Meaning of Spinal Cord Injury
A spinal cord injury (SCI) is an injury to the spinal cord resulting in a change, either temporary or permanent, in the cord's normal motor, sensory, or autonomic function A spinal cord injury, damage to any part of the spinal cord or nerves at the end of the spinal canal, often causes permanent changes in strength, sensation and other body functions below the site of the injury. The spinal cord does not have to be severed in order for a loss of function to occur. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence.
The spinal cord consists of the nerves which connect the brain with the body, and is located in the spinal canal. The spinal canal lies inside the human vertebral column or spine, which is formed by all the vertebrae, the intervertebral discs and ligaments - (More information, including pictures, on the human spinal cord can be found here.)
Spinal cord injuries (SCI's) have the potential to cause both loss of sensation and movement below the site of injury in persons who experience them. People may experience a spinal cord injury through trauma to the spine; for example in either a fall, or through a car accident.
People may experience a spinal cord injury which is either incomplete or complete.
In persons who have experienced an incomplete spinal cord injury, they may have some level of both feeling and movement remaining below the site of their injury. Persons with SCI may experience additional issues involving control of urination and bowel movements. People who have spinal cord injuries involving their neck many times require specific devices in order to assist them with breathing.
Terms such as, 'Paraplegia,' 'Quadriplegia,' and, 'Tetraplegia,' are used to describe medical conditions associated with persons who have experienced a spinal cord injury. The terms are used in classifications based on the level and severity of the injury the person has sustained and the affect on their limbs. Persons who live with SCI often find a need to change aspects of both the home and work environments in order to accommodate their disability; however, they continue to live fulfilling and productive lives.
Common Causes of Spinal Cord Injuries
Car accidents are a common cause of SCI - where the spine breaks and exerts pressure on or tears all or a part of the spinal cord; however, there are a number of other causes. Sports injuries, falls, and gunshot wounds are other causes of SCI's. Diseases such as Spina Bifida, Polio, Transverse Myelitis, and Friedreich's Ataxia also cause spinal cord injuries. Damage done to the person's spinal cord may be referred to as a, 'Lesion.' The level of paralysis the person experiences may be referred to as Quadriplegia or Quadriplegia/Tetraplegia if the injury they have sustained is located in their neck area. If the injury they have sustained is in their Lumbar, Thoracic, or Sacral region, the injury may be referred to as Paraplegia.
There is the potential for a person to experience an injury to either their back or neck, resulting in a fracture, without paralysis. If the person's vertebrae have been fractured or dislocated, but their spinal cord has not been damaged, paralysis may not occur. Spinal cord injury is a defining issue in association with SCI.
Complete and Incomplete Spinal Cord Injury
The terms, 'Complete,' and, 'Incomplete,' in reference to a spinal cord injury are associated with the type of lesion in the person's spine.
- A person who is completely paralyzed below the lesion has a, 'Complete,' SCI.
- A person who experiences partial paralysis below the lesion on their spine has an, 'Incomplete,' SCI.
Persons with incomplete SCI might have some sensation below the lesion, yet have no movement. There are a number of types of incomplete spinal cord injuries. Every person with an incomplete spinal cord injury is unique in regards to their injury.Incomplete SCI's are known as:
- Central Cord Syndrome
- Anterior Cord Syndrome
- Posterior Sequard Syndrome
- Posterior Cord Syndrome
Spinal Cord Injury Rehabilitation
Persons with SCI face a path of rehabilitation that can be lengthy.
The rehabilitation process often involves a Spinal Cord Injury Treatment Unit, Rehabilitation Center, or Spinal Injury Unit.
- Persons with paraplegia may stay in a hospital for up to five months after sustaining the injury.
- Persons with quadriplegia may stay in a hospital for up to six to eight months.
- Hospital stays often involve both rehabilitation and physiotherapy prior to discharge. The person's stay in the hospital may involve teaching to help them adjust to life using a wheelchair and education regarding techniques to make everyday living easier.
Cervical (neck) injuries usually result in full or partial tetraplegia (Quadriplegia). However, depending on the specific location and severity of trauma, limited function may be retained. See the list of C1 to S5 Vertebra functions.
Spinal Cord Injuries (SCI) Include:
- Complete Spinal Cord Injury:Generally persons with a complete spinal cord injury suffer a loss of sensation and motor ability caused by bruising, loss of blood to the spinal cord, or pressure on the spinal cord; cut and severed spinal cords are rare. Generally, complete spinal cord injuries result in total loss of sensation and movement below the site of the injury.
- Incomplete Spinal Cord Injury: An incomplete spinal cord injury does not result in complete loss of movement and sensation below the injury site. These injuries are usually classified as:
- Anterior Cord Syndrome:Damage to the front of the spinal cord, affecting pain, temperature and touch sensation, but leaving some pressure and joint sensation. Often motor function is unaffected.
- Central Cord Syndrome: Form of incomplete spinal cord injury in which some of the signals from the brain to the body are not received, characterized by impairment in the arms and hands and, to a lesser extent, in the legs. Sensory loss below the site of the spinal injury and loss of bladder control may also occur. This syndrome, usually the result of trauma, is associated with damage to the large nerve fibers that carry information directly from the cerebral cortex to the spinal cord. These nerves are particularly important for hand and arm function. Symptoms may include paralysis and/or loss of fine control of movements in the arms and hands, with relatively less impairment of leg movements. The brain's ability to send and receive signals to and from parts of the body below the site of trauma is affected but not entirely blocked.
- Brown-Sequard Syndrome: Injury to the lateral half of the spinal cord. The condition is characterized by the following clinical features found below the level of the lesion - contralateral hemi-sensory anesthesia to pain and temperature, ipsilateral loss of propioception, and ipsilateral motor paralysis. Tactile sensation is generally spared.
- Spinal Contusions: The most common type of spinal cord injury. The spinal cord is bruised but not severed. Inflammation and bleeding occurs near the injury as a result of the injury.
- Injuries to Individual Nerve Cells: Loss of sensory and motor functions in the area of the body to which the injured nerve root corresponds.
Flexion Fracture Pattern
- Compression fracture: While the front (anterior) of the vertebra breaks and loses height, the back (posterior) part of it does not. This type of fracture is usually stable and rarely associated with neurologic problems.
- Axial burst fracture: The vertebra loses height on both the front and back sides. It is often caused by a fall from a height and landing on the feet.
Extension Fracture Pattern
- Flexion/distraction (Chance) fracture: The vertebra is literally pulled apart (distraction). This can happen in accidents such as a head-on car crash, in which the upper body is thrown forward while the pelvis is stabilized by a lap seat belt.
Rotation Fracture Pattern
- Transverse process fracture: This fracture is uncommon and results from rotation or extreme sideways (lateral) bending, and usually does not affect stability.
- Fracture-dislocation: This is an unstable injury involving bone and/or soft tissue in which a vertebra may move off an adjacent vertebra (displaced). These injuries frequently cause serious spinal cord compression.
ASIA SCI Classification
The American Spinal Injury Association (ASIA) first published an international classification of spinal cord injury in 1982, called the International Standards for Neurological and Functional Classification of Spinal Cord Injury.
A - Indicates a "complete" spinal cord injury where no motor or sensory function is preserved in the sacral segments S4-S5.
B - Indicates an "incomplete" spinal cord injury where sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-S5. This is typically a transient phase and if the person recovers any motor function below the neurological level, that person essentially becomes a motor incomplete, i.e. ASIA C or D.
C - Indicates an "incomplete" spinal cord injury where motor function is preserved below the neurological level, and MORE than half of key muscles below the single neurological level of injury have a muscle grade less than 3 (i.e. M 0 - no contraction, no muscle movement, M 1 - trace of contraction, but no movement, or M 2 - movement with gravity eliminated).
D - Indicates an "incomplete" spinal cord injury where motor function is preserved below the neurological level and at least half of the key muscles ( more than 50 percent of the key muscles) below the neurological level have a muscle grade of 3 or more (I.e. M3, M4 or M5, muscle can movement against gravity (3) or with additional resistance (4 & 5)).
E - If motor and sensation function with ISNCSCI are all graded normal (in all segments) and the patient had neurological deficits from SCI before, then the grade is E.
Note: only patients with SCI receive any AIS grade. The following incomplete syndromes are not part of the International Standards examination : central cord syndrome, Brown -Sequard syndrome, anterior cord syndrome, cauda equina syndrome, conus medullaris syndrome and all neurological deficits caused by lesion of lower motor neurons, i.e. brachial plexus lesions.
There is currently no cure for the paralysis associated with spinal cord injuries.
However, there are currently clinical trials being performed involving Olfactory En-sheathing Glial (OEG) cells and Embryonic Stem Cells that show promise.
Facts: SCI and Future Treatment
Today, improved emergency care for people with spinal cord injuries, antibiotics to treat infections, and aggressive rehabilitation can minimize damage to the nervous system and restore function to varying degrees. Advances in research are giving doctors and people living with SCI hope that spinal cord injuries will eventually be repairable. With new surgical techniques and developments in spinal nerve regeneration, cell replacement, neuro-protection, and neuro-rehabilitation, the future for spinal cord injury survivors looks brighter than ever.
In human research, Duke University's Miguel Nicolelis, M.D., revealed groundbreaking details on a brain-machine interface that helps paralyzed patients walk again.
A systematic survey of the scientific literature shows that stem cell therapy can have a statistically significant impact on animal models of spinal cord injury, and points the way for future studies.
Statistics: U.S. Spinal Cord Injury
Spinal Cord Injury Facts
- In the United States there are about 700,000 persons with a disability involving their spinal cord. The disabilities these people have include Multiple Sclerosis, Traumatic Spinal Cord Injury, Poliomyelitis, Spina Bifida, Syningomelia, and Amyotrophic Lateral Sclerosis (ALS).
- Somewhere in America a person sustains a spinal cord injury every forty-one minutes. Approximately eleven-thousand people in America experience a spinal cord injury every year.
- The first year after a person experiences a spinal cord injury is the most expensive medically, costing from $209,000 to $710,000. Each year afterward, medical expenses may range from $14,000 to $127,000 depending on the individual. For a person who has sustained a SCI at age twenty-five, lifetime medical costs may range from $624,000 to $2.8 million.
- Approximately 400,000 people in America have Multiple Sclerosis (MS)). Ten-thousand people face a diagnosis of MS each year. MS is a progressive disease which attacks the myelin sheath surrounding nerve cells in a person's nervous system, blocking transmission of motor signals to their limbs. For unknown reasons, MS affects two to three times as many women as it does men.
- Approximately 70,000 people are living in America with Spina Bifida at this time. Spina Bifida is a neural tube birth defect that causes the spinal column in the person to close incompletely. There are various forms of Spina Bifida.
- Approximately 5,600 people in America are diagnosed with Amyotrophic Lateral Sclerosis, or ALS every year. The incidence of ALS is two-thirds as high as that of MS, and five-times as high as that of Huntington's disease. About 30,000 Americans have ALS, which affects persons of any race or ethnic background.