What is a spinal cord injury?
A spinal cord injury (SCI) is damage to the tight bundle of cells and nerves that sends and receives signals from the brain to and from the rest of the body. The spinal cord extends from the lower part of the brain down through the lower back.
SCI can be caused by direct injury to the spinal cord itself or from damage to the tissue and bones (vertebrae) that surround the spinal cord. This damage can cause temporary or permanent changes in sensation, movement, strength, and body functions below the site of injury.
The extent of disability depends on where along the spinal cord the injury occurs and the severity of the injury. An injury higher on the spinal cord can cause paralysis in most of your body and affect all limbs (tetraplegia or quadriplegia). A lower injury to the spinal cord may cause paralysis affecting your legs and lower body (paraplegia).
A spinal cord injury can damage a few, many, or almost all of the nerve fibers that cross the site of injury. An almost complete recovery is possible for injuries with little to no nerve cell death.
A spinal cord injury can cause one or more symptoms, including:
- Numbness, tingling, or a loss of or changes in sensation in hands and feet
- Paralysis that may happen immediately or develop over time as swelling and bleeding affects the spinal cord
- Pain or pressure in your head, neck, or back
- Loss of movement
- Weakness or inability to move any part of the body
- Unnatural positions of the spine or head
- Loss of bladder and bowel control
- Problems with walking
- Difficulty breathing
- Changes in sexual function
Types of spinal cord injury
A spinal cord injury can be classified by two types: complete or incomplete.
- An incomplete injury means the spinal cord is still able to transmit some messages to or from the brain. People with incomplete injuries retain some sensory function and may have some control of muscle activity below the injury site.
- A complete injury means that there is no nerve communication below the injury site; sensory and motor function below this site is lost.
Primary damage is immediate and is caused directly by the injury. Secondary damage results from inflammation and swelling that can press on your spinal cord and vertebrae, as well as from changes in the activity of cells and cell death.
Anatomy of the spinal cord
The spinal cord is a soft, cylindrical column of tightly bundled nerve cells (neurons and glia), nerve fibers that transmit nerve signals (called axons), and blood vessels. It sends and receives information between the brain and the rest of the body. Millions of nerve cells situated in the spinal cord itself also coordinate complex patterns of movements such as rhythmic breathing and walking.
The spinal cord extends from the brain to the lower back through a canal in the center of the bones of the spine. Like the brain, the spinal cord is protected by three layers of tissue and is surrounded by the cerebrospinal fluid (CSF) that acts as a cushion against shock or injury.
Inside the spinal cord are:
- A collection of neurons and their projections that connect with other nerve cells to transmit and receive information (gray matter)
- Bundles of axons, some of which are coated with a whitish mixture of proteins and fat-like substances (white matter)
Other types of nerve cells sit just outside the spinal cord and relay information to the brain. 31 pairs of nerves, each of which contains thousands of axons, are divided into four regions with individual segments that link the spinal cord to muscles and other parts of the body:
- Cervical spinal nerves (C1 to C8) emerge from the spinal cord in the neck and control signals to the back of the head, the neck and shoulders, the arms and hands, and the diaphragm.
- Thoracic spinal nerves (T1 to T12) emerge from the spinal cord in the upper mid-back and control signals to the chest muscles, some muscles of the back, and many organ systems, including parts of the abdomen.
- Lumbar spinal nerves (L1 to L5) emerge from the spinal cord in the low back and control signals to the lower parts of the abdomen and the back, the buttocks, some parts of the external genital organs, and parts of the leg.
- Sacral spinal nerves (S1 to S5) emerge from the spinal cord in the low back and control signals to the thighs and lower parts of the legs, the feet, most of the external genital organs, and the area around the anus.
The spinal column, which surrounds and protects the spinal cord, is made up of 33 rings of bone (vertebrae), pads of semi-rigid cartilage (discs), and narrow spaces called foramen that act as passages for spinal nerves to travel to and from the rest of the body. The spinal cord is particularly vulnerable to direct injury within these areas.
Who is more likely to get a spinal cord injury?
Motor vehicle accidents and catastrophic falls are the most common causes of SCI in the U.S. The rest are due to acts of violence (primarily gunshot wounds and assaults), sports injuries, medical or surgical injury, industrial accidents, diseases and conditions that can damage the spinal cord, and other less common causes. Risk factors include age (either being between the ages of 16 and 30, or after age 65 for dangerous falls), alcohol use, certain diseases, or not wearing proper gear, such as a seat belt or protective sports equipment.
How is a spinal cord injury diagnosed and treated?
Diagnosing a spinal cord injury
The emergency room physician will check for movement or sensation at or below your level of injury, as well as proper breathing, responsiveness, and weakness. Emergency medical tests for a spinal cord injury include:
- Magnetic resonance imaging (MRI) produces detailed three-dimensional images of body structures, including tissues, organs, bones, and nerves. It can show brain and spinal trauma from injury, herniated discs (cartilage located between the vertebrae), vascular (blood vessel) irregularities, bleeding, inflammation that might compress the spine and spinal cord, and injury to the ligaments that support the cervical spine.
- Computerized tomography (CT) provides rapid, clear two-dimensional images of organs, bones, and tissues. CT can detect bone fractures, bleeding, and spinal stenosis (narrowing of the spinal canal).
- X-rays show two-dimensional images of most parts of the body, such as a joint or major organ system. Misalignment of or fracture to vertebrae can be seen within minutes.
Treating spinal cord injury
At the accident scene, if a spinal cord injury is suspected, emergency personnel will place a rigid collar around your neck and carefully place you on a backboard to prevent further damage to your spinal cord. They may use sedatives to relax and prevent movement. A breathing tube may be inserted if you have problems breathing and your body isn't receiving enough oxygen from the lungs.
Immediate treatment at the trauma center may include:
- Realigning your spine using a rigid brace or mechanical force, which is usually done as soon as possible to stabilize your spine and prevent additional damage.
- Surgery to remove any fractured vertebrae, bone fragments, herniated discs, or other objects that are pressing on your spinal column. Spinal decompression surgery to relieve pressure within the spinal column may also be necessary in the days after injury. Results of a neurosurgical study show that, in some cases, earlier surgery is associated with better functional recovery.
Possible complications of SCI and treatment may include:
- Breathing problems—About one-third of people with a neck injury will need temporary or permanent help with breathing and may require an inserted artificial breathing tube. Any injury to the spinal cord between the C1-C4 segments can stop breathing as the nerves in this region cause the diaphragm to move and the lungs to expand. Special training regarding breathing and swallowing may be needed.
- Pneumonia—Respiratory complications are the leading cause of death in people with SCI, commonly as a result of pneumonia. If you are placed on a ventilator to assist with breathing (intubation), you are at increased risk of developing pneumonia. You must be carefully monitored and treated with antibiotics if symptoms of pneumonia appear. Clearing secretions from the throat and preventing food and liquids from being sucked into the lungs (aspiration) can prevent pneumonia.
- Circulatory problems—Changes in circulation, including blood pressure instability, abnormal heart rhythms (arrhythmias), and blood clots may appear days after your injury. Blood pressure needs to be closely monitored. Because the brain's control of the cardiac nerves can be cut off, your heart can beat at a dangerously slow pace, or it can pound rapidly and irregularly. Changes in the control of blood vessels can cause them to widen and allow blood to pool in the small arteries far away from the heart. People with spinal cord injuries are at increased risk for blood clots due to stagnation of blood flow in the large veins in the legs. Treatment includes anticoagulant drugs and compression stockings to increase blood flow in the lower legs and feet.
- Spasticity and decreased muscle tone—Your reflexes may become exaggerated over time, causing muscle spasticity that may require special treatment. Muscles may deteriorate due to underuse.
- Autonomic dysreflexia—Autonomic dysreflexia is a life-threatening reflex action that primarily affects those with injuries to the neck or upper back. Symptoms may include flushing or sweating, a pounding headache, anxiety, sudden increase in blood pressure, vision changes, or goose bumps on the arms and legs. If possible, you should be kept in a sitting position to keep blood flowing to the legs and feet and help reduce blood pressure.
- Pressure sores (also known as pressure ulcers)—Pressure sores are areas of skin that have broken down because of continuous pressure on the skin and reduced blood flow to the area. People with paraplegia and tetraplegia are susceptible to pressure sores. As a result, individuals must be shifted periodically by a caregiver.
- Pain—Some people who have spinal cord nerve damage develop neurogenic pain—pain or an intense burning or stinging sensation that may be constant due to extreme physical sensitivity (hypersensitivity) in some parts of the body. It can either be spontaneous or triggered by a variety of factors and can occur even in parts of the body that have lost sensation. Treatments for chronic pain include medications, acupuncture, spinal or brain electrical stimulation, and surgery. However, none of these treatments are completely effective at relieving neurogenic pain.
- Bladder and bowel problems—You may need to use a catheter to empty your bladder or learn ways to empty the bowels. A change in diet may be needed.
- Sexual function—Depending on the level of injury and recovery from the trauma, sexual function and fertility may be affected. A urologist and other specialists can suggest different options for sexual functioning and health.
- Depression—Many people living with a spinal cord injury may develop depression due to lifestyle changes. Therapy and medicine may help treat depression and other mental health conditions.
Once someone begins to cope psychologically and emotionally, the next concern is how to live with disabilities. Doctors are now able to predict with reasonable accuracy the likely long-term outcome of spinal cord injuries. This helps people experiencing SCI to set achievable goals for themselves and gives families and loved ones a realistic set of expectations for the future.
Rehabilitation programs combine physical therapies with skill-building activities and counseling to provide social and emotional support, as well as to increase independence and quality of life. The rehabilitation team is usually led by a doctor specializing in physical medicine and rehabilitation (physiatrist) and often includes social workers, physical and occupational therapists, recreational therapists, rehabilitation nurses, rehabilitation psychologists, vocational counselors, nutritionists, a case worker, and other specialists.
The initial phase of rehabilitation is focused on regaining communication skills and leg and arm strength. For some individuals, mobility will only be possible with assistive or adaptive devices such as a walker, leg braces, or a wheelchair. Communication skills such as writing, typing, and using the telephone may also require adaptive devices for those with tetraplegia.
- Physical therapy includes exercise programs geared toward strengthening muscles.
- Occupational therapy helps redevelop fine motor skills, particularly those needed to perform activities of daily living (ADLs) such as getting in and out of a bed, self-grooming, eating, and using the toilet. You may learn how to cope with spasticity, autonomic dysreflexia, and neurogenic pain.
- Vocational rehabilitation includes identifying basic work skills and physical and cognitive capabilities to determine the likelihood for employment; identifying potential workplaces and any assistive equipment that will be needed; and arranging a user-friendly workplace.
- Educational training can help you develop skills for a new line of work that may be less dependent upon physical abilities and more dependent upon computer or communication skills. People with SCI or other disabilities are encouraged to participate in activities that provide a sense of satisfaction and self-esteem, such as educational classes, hobbies, special interest groups, and participating in family and community events.
- Recreation therapy encourages people with SCI to participate in sports or activities at their level of mobility, as well as achieve a more balanced lifestyle that provides opportunities for socialization and self-expression.
Adaptive devices may help people with spinal cord injury to regain independence and improve mobility and quality of life. Depending on the severity of the injury, people may need a wheelchair, electronic stimulators, assisted training with walking, neural prosthetics (assistive devices that may stimulate the nerves to restore lost functions), computer adaptations, and other computer-assisted technology.
What are the latest updates on spinal cord injury?
The National Institute of Neurological Disorders and Stroke (NINDS), a component of the National Institutes of Health (NIH), is a primary funder of research on the brain and spinal cord. NIH is the leading supporter of biomedical research in the world.
The Brain Research through Advancing Innovative Technologies® (BRAIN) Initiative brings multiple federal agencies and private organizations together to develop and apply new technologies to understand how complex circuits of nerve cells enable thinking, movement control, and perception. SCI research as part of the BRAIN Initiative includes:
- Exploring brain circuits to better understand the sensory and motor basis of behavior
- Next-generation neural prosthetics, or devices that connect to the nervous system and restore functions lost due to disease or injury
- Improved brain and spinal cord imaging
- New brain-computer interface devices
Basic spinal cord function research studies how the spinal cord develops, processes sensory information, controls movement, and generates rhythmic patterns like walking and breathing. Basic studies using cells and animal models provide an essential foundation for developing interventions for spinal cord injury.
Research on injury mechanisms focuses on what causes immediate harm and on the cascade of helpful and harmful bodily reactions that protect from or contribute to damage in the hours and days following a spinal cord injury. This includes testing of neuroprotective interventions in laboratory animals.
Current research on SCI is focused on advancing our understanding of the four key principles of spinal cord repair:
- Neuroprotection—Preventing cell death and protecting surviving nerve cells from further damage, including using drugs to reduce nerve cell death and lowering of the body's core temperature to reduce cell and blood vessel damage and improve functional outcome.
- Repair and regeneration—Encouraging the spinal cord's intrinsic ability to self-repair and stimulating the regrowth of nerve cell projections (axons), including cell transplants, natural growth-promoting substances, and bioengineered growth scaffolds.
- Cell-based therapies—Replacing damaged nerve or support cells with other cell types, including stem cells, to regenerate neuronal growth and create new cell connections.
- Neuroplasticity—Retraining central nervous system circuits to restore body functions and form new nerve connections and pathways following injury or cell death through techniques like rehabilitation, electrical stimulation, robot-assisted training, and brain-computer interface technology that may help with voluntary muscle movement and coordination.
Developing neural prosthetics
Neural engineering strategies build on decades of pioneering NINDS investment that established the field of neural prosthetics. For example, researchers are developing a networked functional electrical stimulation system to restore physical independence through combined implants for hand function, postural control, and bowel and bladder control.
NINDS has also led development of experimental brain computer interfaces that enable people to control a computer cursor or robotic arm directly from their brains.
More information about spinal cord injury research may be found using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies. RePORTER also includes links to publications and resources from these projects.
For research articles and summaries on spinal cord injury, search PubMed, which contains citations from medical journals and other sites.
How can I or my loved one help improve care for people with a spinal cord injury?
Consider participating in a clinical trial so clinicians and scientists can learn more about SCI. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.
All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.
For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with spinal cord injury at Clinicaltrials.gov, a searchable database of clinical trials.
Spinal cord injury and rehabilitation research centers maintain registries of people interested in participating in ongoing or future clinical studies. A multi-site network supported by the Christopher and Dana Reeve Foundation called the NeuroRecovery Network (NRN) accepts volunteer research participants.
Where can I find more information about spinal cord injuries?
The following organizations and resources help individuals, families, friends, and caregivers of people living with a spinal cord injury:
Christopher and Dana Reeve Foundation
Phone: 973-379-2690 or 800-225-0292
Miami Project to Cure Paralysis
Phone: 305-243-6001 or 800-782-6387
National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR)
Phone: 202-401-4634 or 202-245-7316
National Rehabilitation Information Center (NARIC)
Phone: 301-459-5900 or 800-346-2742
Paralyzed Veterans of America (PVA)
United Spinal Association
Phone: 718-803-3782 or 800-962-9629