Find information on thousands of medical conditions and prescription drugs.

Spinal cord injury

Spinal cord injury, or myelopathy, is a disturbance of the spinal cord that results in loss of sensation and mobility. The two common types of spinal cord injury are: more...

Sabinas brittle hair...
Sacral agenesis
Saethre-Chotzen syndrome
Salla disease
Sandhoff disease
Sanfilippo syndrome
Say Meyer syndrome
Scarlet fever
Schamberg disease...
Schmitt Gillenwater Kelly...
Scimitar syndrome
Selective mutism
Sensorineural hearing loss
Septo-optic dysplasia
Serum sickness
Severe acute respiratory...
Severe combined...
Sezary syndrome
Sheehan syndrome
Short bowel syndrome
Short QT syndrome
Shprintzen syndrome
Shulman-Upshaw syndrome
Shwachman syndrome
Shwachman-Diamond syndrome
Shy-Drager syndrome
Sickle-cell disease
Sickle-cell disease
Sickle-cell disease
Silver-Russell dwarfism
Sipple syndrome
Sjogren's syndrome
Sly syndrome
Smith-Magenis Syndrome
Soft tissue sarcoma
Sotos syndrome
Spasmodic dysphonia
Spasmodic torticollis
Spinal cord injury
Spinal muscular atrophy
Spinal shock
Spinal stenosis
Spinocerebellar ataxia
Splenic-flexure syndrome
Squamous cell carcinoma
St. Anthony's fire
Stein-Leventhal syndrome
Stevens-Johnson syndrome
Stickler syndrome
Stiff man syndrome
Still's disease
Stomach cancer
Strep throat
Strumpell-lorrain disease
Sturge-Weber syndrome
Subacute sclerosing...
Sudden infant death syndrome
Sugarman syndrome
Sweet syndrome
Swimmer's ear
Swyer syndrome
Sydenham's chorea
Syndrome X
Synovial osteochondromatosis
Synovial sarcoma
Systemic carnitine...
Systemic lupus erythematosus
Systemic mastocytosis
Systemic sclerosis
  • Trauma : automobile accidents, falls, gunshots, diving accidents, etc.
  • Disease : polio, spina bifida, tumors, Friedreich's ataxia, etc.

It is important to note that the spinal cord does not have to be completely severed for there to be a loss of function. In fact, the spinal cord remains intact in most cases of spinal cord injury.

Spinal cord injuries are not the same as back injuries such as ruptured disks, spinal stenosis or pinched nerves. It is possible to "break one's neck or back" and not sustain a spinal cord injury if only the vertebrae are damaged, but the spinal cord remains intact.

About 450,000 people in the United States live with spinal cord injury, and there are about 11,000 new spinal cord injuries every year. The majority of them (78%) involve males between the ages of 16-30 and result from motor vehicle accidents (42%), violence (24%), or falls (22%).

The Effects of Spinal Cord Injury

The exact effects of a spinal cord injury vary according to the type and level injury, and can be organized into two types:

  • In a complete injury, there is no function below the level of the injury. Voluntary movement is impossible and physical sensation is impossible. Complete injuries are always bilateral, that is, both sides of the body are affected equally.
  • A person with an incomplete injury retains some sensation below the level of the injury. Incomplete injuries are variable, and a person with such an injury may be able to move one limb more than another, may be able to feel parts of the body that cannot be moved, or may have more functioning on one side of the body than the other.

In addition to a loss of sensation and motor function below the point of injury, individuals with spinal cord injuries will often experience other changes.

Bowel and bladder function is associated with the sacral region of the spine, so it is very common to experience dysfunction of the bowel and bladder. Sexual function is also associated with the sacral region, and is also affected very often. Injuries very high on the spinal cord (C-1, C-2) will often result in a loss of many involuntary functions, such as breathing, necessitating mechanical ventilators or diaphragmatic pacemakers. Other effects of spinal cord injury can include an inability to regulate heart rate (and therefore blood pressure), reduced control of body temperature, inability to sweat below the level of injury, and chronic pain.

The Location of the Injury

Knowing the exact level of the injury on the spinal cord is important when predicting what parts of the body might be affected by paralysis and loss of function.


[List your site here Free!]

Spinal cord injury
From Gale Encyclopedia of Medicine, 4/6/01 by Richard Robinson


Spinal cord injury is damage to the spinal cord that causes loss of sensation and motor control.


Approximately 10,000 new spinal cord injuries (SCIs) occur each year in the United States. About 250,000 people are currently affected. Spinal cord injuries can happen to anyone at any time of life. The typical patient, however, is a man between the ages of 19 and 26, injured in a motor vehicle accident (about 50% of all SCIs), a fall (20%), an act of violence (15%), or a sporting accident (14%). Most SCI patients are white, but the nonwhite fraction of SCI patients is larger than the nonwhite fraction of the general population. Alcohol or other drug abuse plays an important role in a large percentage of all spinal cord injuries. Six percent of people who receive injuries to the lower spine die within a year, and 40% of people who receive the more frequent higher injuries die within a year.

Short-term costs for hospitalization, equipment, and home modifications are approximately $140,000 for an SCI patient capable of independent living. Lifetime costs may exceed one million dollars. Costs may be 3-4 times higher for the SCI patient who needs long-term institutional care. Overall costs to the American economy in direct payments and lost productivity are more than $10 billion per year.

Causes & symptoms


The spinal cord is about as big around as the index finger. It descends from the brain down the back through hollow channels of the backbone. The spinal cord is made of nerve cells (neurons). The nerve cells carry sensory data from the areas outside the spinal cord (periphery) to the brain, and they carry motor commands from brain to periphery. Peripheral neurons are bundled together to make up the 31 pairs of peripheral nerve roots. The peripheral nerve roots enter and exit the spinal cord by passing through the spaces between the stacked vertebrae. Each pair of nerves is named for the vertebra from which it exits. These are known as:

  • C1-8. These nerves enter from the eight cervical or neck vertebrae.
  • T1-12. These nerves enter from the thoracic or chest vertebrae.
  • L1-5. These nerves enter from the lumbar vertebrae of the lower back.
  • S1-5. These nerves enter through the sacral or pelvic vertebrae.
  • Coccygeal. These nerves enter through the coccyx or tailbone.

Peripheral nerves carry motor commands to the muscles and internal organs, and they carry sensations from these areas and from the body's surface. (Sensory data from the head, including sight, sound, smell, and taste, do not pass through the spinal cord and are not affected by most SCIs.) Damage to the spinal cord interrupts these signals. The interruption damages motor functions that allow the muscles to move, sensory functions such as feeling heat and cold, and autonomic functions such as urination, sexual function, sweating, and blood pressure.

Spinal cord injuries most often occur where the spine is most flexible, in the regions of C5-C7 of the neck, and T10-L2 at the base of the rib cage. Several physically distinct types of damage are recognized. Sudden and violent jolts to nearby tissues can jar the cord. This jarring causes a temporary spinal concussion. Concussion symptoms usually disappear completely within several hours. A spinal contusion or bruise is bleeding within the spinal column. The pressure from the excess fluid may kill spinal cord neurons. Spinal compression is caused by some object, such as a tumor, pressing on the cord. Lacerations or tears cause direct damage to cord neurons. Lacerations can be caused by bone fragments or missiles such as bullets. Spinal transection describes the complete severing of the cord. Most spinal cord injuries involve two or more of these types of damage.


Paralysis and loss of sensation

The extent to which movement and sensation are damaged depends on the level of the spinal cord injury. Nerves leaving the spinal cord at different levels control sensation and movement in different parts of the body. The distribution is roughly as follows:

  • C1-C4: head and neck.
  • C3-C5: diaphragm (chest and breathing).
  • C5-T1: shoulders, arms and hands.
  • T2-T12: chest and abdomen (excluding internal organs).
  • L1-L4: abdomen (excluding internal organs), buttocks, genitals, and upper legs.
  • L4-S1: legs.
  • S2-S4: genitals and muscles of the perineum.

Damage below T1, which lies at the base of the rib cage, causes paralysis and loss of sensation in the legs and trunk below the injury. Injury at this level usually does no damage to the arms and hands. Paralysis of the legs is called paraplegia. Damage above T1 involves the arms as well as the legs. Paralysis of all four limbs is called quadriplegia or tetraplegia. Cervical or neck injuries not only cause quadriplegia but also may cause difficulty in breathing. Damage in the lower part of the neck may leave enough diaphragm control to allow unassisted breathing. Patients with damage at C3 or above, just below the base of the skull, require mechanical assistance to breathe.

Symptoms also depend on the extent of spinal cord injury. A completely severed cord causes paralysis and loss of sensation below the wound. If the cord is only partially severed, some function will remain below the injury. Damage limited to the front portion of the cord causes paralysis and loss of sensations of pain and temperature. Other sensation may be preserved. Damage to the center of the cord may spare the legs but paralyze the arms. Damage to the right or left half causes loss of position sense, paralysis on the side of the injury, and loss of pain and temperature sensation on the opposite side.

Deep venous thrombosis

Blood does not flow normally to a paralyzed limb that is inactive for long periods. The blood pools in the deep veins and forms clots, a condition known as deep vein thrombosis. A clot or thrombus can break free and lodge in smaller arteries in the brain, causing a stroke, or in the lungs, causing pulmonary embolism.

Pressure ulcers

Inability to move also leads to pressure ulcers or bed sores. Pressure ulcers form where skin remains in contact with a bed or chair for a long time. The most common sites of pressure ulcers are the buttocks, hips, and heels.

Spasticity and contracture

A paralyzed limb is incapable of active movement, but the muscle still has tone, a constant low level of contraction. Normal muscle tone requires communication between the muscle and the brain. Spinal cord injury prevents the brain from telling the muscle to relax. The result is prolonged muscle contraction or spasticity. Because the muscles that extend and those that bend a joint are not usually equal in strength, the involved joint is bent, often severely. This constant pressure causes deformity. As the muscle remains in the shortened position over several weeks or months, the tendons remodel and cause permanent muscle shortening or contracture. When muscles have permanently shortened, the inner surfaces of joints, such as armpits or palms, cannot be cleaned and the skin breaks down in that area.

Heterotopic ossification

Heterotopic ossification is an abnormal deposit of bone in muscles and tendons that may occur after injury. It is most common in the hips and knees. Initially heterotopic ossification causes localized swelling, warmth, redness, and stiffness of the muscle. It usually begins one to four months after the injury and is rare after one year.

Autonomic dysreflexia

Body organs that regulate themselves, such as the heart, gastrointestinal tract, and glands, are controlled by groups of nerves called autonomic nerves. Autonomic nerves emerge from three different places: above the spinal column, in the lower back from vertebrae T1-L4, and from the lowest regions of the sacrum at the base of the spine. In general, these three groups of autonomic nerves operate in balance. Spinal cord injury can disrupt this balance, a condition called autonomic dysreflexia or autonomic hyperreflexia. Patients with injuries at T6 or above are at greatest risk.

In autonomic dysreflexia, irritation of the skin, bowel, or bladder causes a highly exaggerated response from autonomic nerves. This response is caused by the uncontrolled release of norepinephrine, a hormone similar to adrenaline. Uncontrolled release of norepinephrine causes a rapid rise in blood pressure and a slowing of the heart rate. These symptoms are accompanied by throbbing headache, nausea, anxiety, sweating, and goose bumps below the level of the injury. The elevated blood pressure can rapidly cause loss of consciousness, seizures, cerebral hemorrhage, and death. Autonomic dysreflexia is most often caused by an over-full bladder or bladder infection, impaction or hard impassable fecal mass in the bowel, or skin irritation from tight clothing, sunburn, or other irritant. Inability to sense these irritants before the autonomic reaction begins is a major cause of dysreflexia.

Loss of bladder and bowel control

Bladder and bowel control require both motor nerves and the autonomic nervous system. Both of these systems may be damaged by SCI. When the autonomic nervous system triggers an urge to urinate or defecate, continence is maintained by contracting the anal or urethral sphincters. A sphincter is a ring of muscle that contracts to close off a passage or opening in the body. When the neural connections to these muscles are severed, conscious control is lost. In addition, loss of feeling may prevent sensations of fullness from reaching the brain. To compensate, the patient may help empty the bowel or bladder by using physical maneuvers that stimulate autonomic contractions before they would otherwise begin. However, the patient may not be able to relax the sphincters. If the sphincters cannot be relaxed, the patient will retain urine or feces.

Retention of urine may cause muscular changes in the bladder and urethral sphincter that make the problem worse. Urinary tract infection is common. Retention of feces can cause impaction. Symptoms of impaction include loss of appetite and nausea. Untreated impaction may cause perforation of the large intestine and rapid overwhelming infection.

Sexual dysfunction

Men who have sustained SCI may be unable to achieve an erection or ejaculate. Sperm formation may be abnormal too, reducing fertility. Fertility and the ability to achieve orgasm are less impaired for women. Women may still be able to become pregnant and deliver vaginally with proper medical care.


The location and extent of spinal cord injury is determined with computed tomography scans (CT scans), magnetic resonance imaging (MRI) scans, and x rays. X rays may be enhanced with an injected contrast dye.


A person who may have a spinal cord injury should not be moved. Treatment of SCI begins with immobilization. This strategy prevents partial injuries of the cord from severing it completely. Use of splints to completely immobilize suspected SCI at the scene of the injury has helped reduce the severity of spinal cord injuries in the last two decades. Intravenous methylprednisone, a steroidal anti-inflammatory drug, is given during the first 24 hours to reduce inflammation and tissue destruction.

Rehabilitation after spinal cord injury seeks to prevent complications, promote recovery, and make the most of remaining function. Rehabilitation is a complex and long-term process. It requires a team of professionals, including a neurologist, physiatrist or rehabilitation specialist, physical therapist, and occupational therapist. Other specialists who may be needed include a respiratory therapist, vocational rehabilitation counselor, social worker, speech-language pathologist, nutritionist, special education teacher, recreation therapist, and clinical psychologist. Support groups provide a critical source of information, advice, and support for SCI patients.

Paralysis and loss of sensation

Some limited mobility and sensation may be recovered, but the extent and speed of this recovery cannot be predicted. Experimental electrical stimulation has been shown to allow some control of muscle contraction in paraplegia. This experimental technique offers the possibility of unaided walking. Further development of current control systems will be needed before useful movement is possible outside the laboratory.

The physical therapist focuses on mobility, to maintain range of motion of affected limbs and reduce contracture and deformity. Physical therapy helps compensate for lost skills by using those muscles that are still functional. It also helps to increase any residual strength and control in affected muscles. A physical therapist suggests adaptive equipment such as braces, canes, or wheelchairs.

An occupational therapist works to restore ability to perform the activities of daily living, such as eating and grooming, with tools and new techniques. The occupational therapist also designs modifications of the home and workplace to match the individual impairment.

A pulmonologist or respiratory therapist promotes airway hygiene through instruction in assisted coughing techniques and postural drainage. The respiratory professional also prescribes and provides instruction in the use of ventilators, facial or nasal masks, and tracheostomy equipment where necessary.

Pressure ulcers

Pressure ulcers are prevented by turning in bed at least every two hours. The patient should be turned more frequently when redness begins to develop in sensitive areas. Special mattresses and chair cushions can distribute weight more evenly to reduce pressure. Electrical stimulation is sometimes used to promote muscle movement to prevent pressure ulcers.

Spasticity and contracture

Range of motion (ROM) exercises help to prevent contracture. Chemicals can be used to prevent contractures from becoming fixed when ROM exercise is inadequate. Phenol or alcohol can be injected onto the nerve or botulinum toxin directly into the muscle. Botulinum toxin is associated with fewer complications, but it is more expensive than phenol and alcohol. Contractures can be released by cutting the shortened tendon or transferring it surgically to a different site on the bone where its pull will not cause as much deformity. Such tendon transfers may also be used to increase strength in partially functional extremities.

Heterotopic ossification

Etidronate disodium (Didronel), a drug that regulates the body's use of calcium, is used to prevent heterotopic ossification. Treatment begins three weeks after the injury and continues for 12 weeks. Surgical removal of ossified tissue is possible.

Autonomic dysreflexia

Autonomic dysreflexia is prevented by bowel and bladder care and attention to potential irritants. It is treated by prompt removal of the irritant. Drugs to lower blood pressure are used when necessary. People with SCI should educate friends and family members about the symptoms and treatment of dysreflexia, because immediate attention is necessary.

Loss of bladder and bowel control

Normal bowel function is promoted through adequate fluid intake and a diet rich in fiber. Evacuation is stimulated by deliberately increasing the abdominal pressure, either voluntarily or by using an abdominal binder.

Bladder care involves continual or intermittent catheterization. The full bladder may be detected by feeling its bulge against the abdominal wall. Urinary tract infection is a significant complication of catheterization and requires frequent monitoring.

Sexual dysfunction

Counseling can help in adjusting to changes in sexual function after spinal cord injury. Erection may be enhanced through the same means used to treat erectile dysfunction in the general population.


The prognosis of SCI depends on the location and extent of injury. Injuries of the neck above C4 with significant involvement of the diaphragm hold the gravest prognosis. Respiratory infection is one of the leading causes of death in long-term SCI. Overall, 85% of SCI patients who survive the first 24 hours are alive 10 years after their injuries. Recovery of function is impossible to predict. Partial recovery is more likely after an incomplete wound than after the spinal cord has been completely severed.


Risk of spinal cord injury can be reduced through prevention of the accidents that lead to it. Chances of injury from automobile accidents, the major cause of SCIs, can be significantly reduced by driving at safe speeds, avoiding alcohol while driving, and using seat belts.

Key Terms

Autonomic nervous system
The part of the nervous system that controls involuntary functions such as sweating and blood pressure.
Botulinum toxin
Any of a group of potent bacterial toxins or poisons produced by different strains of the bacterium .
Computed tomography (CT)
An imaging technique in which cross-sectional x rays of the body are compiled to create a three-dimensional image of the body's internal structures.
Magnetic resonance imaging (MRI)
An imaging technique that uses a large circular magnet and radio waves to generate signals from atoms in the body. These signals are used to construct images of internal structures.
Of or pertaining to motion, the body apparatus involved in movement, or the brain functions that direct purposeful activity.
Motor nerve
Motor or efferent nerve cells carry impulses from the brain to muscle or organ tissue.
Peripheral nervous system
The part of the nervous system that is outside the brain and spinal cord. Sensory, motor, and autonomic nerves are included.
Postural drainage
The use of positioning to drain secretions from the bronchial tubes and lungs into the trachea or windpipe.
Range of motion (ROM)
The range of motion of a joint from full extension to full flexion (bending) measured in degrees like a circle.
Sensory nerves
Sensory or afferent nerves carry impulses of sensation from the periphery or outward parts of the body to the brain. Sensations include feelings, impressions, and awareness of the state of the body.
An action or thought undertaken or controlled by a person's free will or choice.

Further Reading

For Your Information


  • Bradley, Walter G., et al., eds. Neurology in Clinical Practice, 2nd ed. Boston: Butterworth-Heinemann, 1996.
  • Martini, F. Fundamentals of Anatomy and Physiology. Englewood Cliffs, NJ: Prentice Hall, 1989.
  • Yarkony, Gary M., ed. Spinal Cord Injury: Medical Management and Rehabilitation. Gaithersburg, Maryland: Aspen Publishers, Inc., 1994.


  • The National Spinal Cord Injury Association. 8300 Colesville Road, Silver Spring, Maryland 20910. (301) 588-6959.

Gale Encyclopedia of Medicine. Gale Research, 1999.

Return to Spinal cord injury
Home Contact Resources Exchange Links ebay