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SPINAL CHORD INJURIES
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The spinal cord is the conduit through which nerve impulses travel from the various parts of the body to the brain and from the brain to the body. It is encased in the spinal column, providing a hard, bony shield for the cord. The cord itself is rather sensitive and very easily damaged.
Because the spinal cord is protected by the spinal column, it requires a significant amount of force to cause trauma to the spinal cord. Therefore, spinal cord injuries are usually the result of calamitous events such as motor vehicle accidents, gunshot wounds, sporting accidents, and falls from high places. Many spinal cord injuries are the result of risky behavior, misadventure or violence, and are more prevalent among younger persons than older persons. Because there are significant functional implications with spinal cord injuries in vocational development and other activities of life, and because they are particularly likely to occur in young persons, spinal cord injuries are a significant rehabilitation issue.
SPINAL ANATOMY AND SPINAL TRAUMA
The spinal cord is divided into 31 segments and five categories. The highest levels of the spinal column are referred to as the Cervical spine and has five segments, which are abbreviated C1 to C5; the lower numbers indicate the segment closer to the brain. Below the Cervical spine is the Thoracic spine, with twelve segments (T1 to T12). Next is the Lumbar spine with five segments (L1 to L5) and the Sacral spine (S1 to S5). At the bottom of the spine is the Coccyx, or tailbone, which has only one segment.
Each of the spinal segments (except the Coccyx) corresponds to a specific vertebrae and spinal nerve. The nerves of the spine exit through side openings between the vertebrae called intervertebral foramina. Most of the spinal nerves exit and enter in an area almost directly adjacent to their respective segment of the spine. However, the spinal cord does not run the entire length of the spine, and actually ends at about the level of the L1 vertebra. The nerves in spinal segments below this point run down the spine and exit and enter the spine at a lower point. This point of indirect exit of the spinal nerves is referred to as the Cauda Equina.
Each spinal nerve contains anterior horns and posterior horns. The anterior horns carry messages away from the brain to the various parts of the body while the posterior horns carry messages from the body to the brain. Each of the spinal nerve roots controls a particular set of muscles in the body as well as physical sensation in those areas. If the spinal cord is completely severed at a given point, no nerve impulses will be able to travel below the point of the injury, either to or from the brain.
Spinal trauma usually results from fracture or dislocation of vertebrae, causing the spinal cord to be bruised, crushed, torn, or cut. In addition, after the injury there may be significant edema (swelling) in the area of the injury, and the pressure this creates can cause additional trauma to the spine. A priority in initial treatment of spinal cord injury is the reduction of swelling against the spine to prevent damage to the spinal cord from worsening.
Spinal cord injuries are referred to as being complete or incomplete. Complete spinal cord injuries prevent any movement of nerve impulses from or to points below the injuries. Incomplete spinal cord injuries may allow for sensation in parts of the spine that have not been injured; in other words, only the parts of the spine which have directly suffered trauma do not function, and function is retained below and above the point of the injury. This can affect either anterior or posterior horns or both. Incomplete spinal cord injuries also refer to injuries in which movement and sensation are still possible in the area of the injury and the subordinate spinal nerves, but the function is weakened or abnormal.
QUADRIPLEGIA
Quadriplegia is a term that translates to weakness of all four limbs of the body, and can refer to a number of medical conditions, such as cerebral palsy or stroke. It is most commonly associated with spinal cord injury and many individuals think that it refers to complete paralysis of both the upper and lower extremities. In fact, any involvement of all four limbs, total or complete, constitutes classification of the disorder as quadriplegia.
In spinal cord injury, individuals with quadriplegia will have complete involvement of the lower extremities (usually total paralysis) together with some loss of function of the upper extremities that can be partial or total, depending upon the level of the injury. Injuries to the spinal column in any of the cervical vertebra or in the first thoracic vertebrae cause quadriplegia.
The following is a list of the effects of quadriplegic injuries at each spinal cord segment:
C1 and C2: Control the muscles of the neck and face. C3 and C4: Diaphragm Injuries at the C1 through C3 level are incompatible with life because of their effect upon respiration (the diaphragm accounts for 75% of breathing capacity). Individuals who survive spinal cord injuries at this level must have prompt first aid by individuals who know how to administer artificial respiration. The individual will be dependent upon an artificial respirator for assistance with breathing for the remainder of their lives. Many of individuals with these injuries may be placed in nursing homes. (C3 is sometimes referred to as the "hangman's vertebrae" because it is fractured when an individual is hanged, causing death from asphyxiation). At the C4 level, there is some control of the diaphragm and breathing without a respirator is usually possible. At these levels, individuals may be able to move objects with mouth sticks and operate electric wheelchairs with chin controls or "sip and puff" switches controlled by breathing. There is complete paralysis of the trunk and the upper extremities.
C5-C6-C7: Deltoid Muscles (shoulder movement)
Biceps (Extension and flexion of the forearm)
Extensor Carpi Radialis (lifting up the hand at the wrist)
Pronator Teres (Placing palm downward)
Triceps (Straightening the elbow)At the C5 level the individual will definitely be capable of breathing without assistance but is totally dependent upon attendant care for activities of daily living. They are unable to move any of the upper extremities. Ambulation is possible with the use of an electric wheelchair activated by chin cup or mouth stick. Powered hand splints may allow individuals to move small objects placed on a table or tray in front of them.
At the C6 level there is ability to extend the arm, (although the wrist is immobile), allowing a degree of independence in transfers (i.e., wheelchair to bed and automobile). The arm can be moved at the shoulder and elbow, allowing individuals to use a manual wheelchair (although electric chairs may still be appropriate), and the individual can learn to drive automobiles with hand controls. Dressing and care of personal hygiene are possible with assistive devices but standby attendant care is recommended. Splinting of the hand allows the individual to write, although slowly and with limited penmanship.
At C7 persons may control the shoulder, elbow and wrists but cannot close the fingers or thumb. Independence is greater than at C6, and with special splints individuals are capable of manipulation of objects, typing/keyboarding, and writing. This is the first level at which total independence without the need for attendant care is possible.
C8-T1: Extensor Digitorum Communis (straightening the knuckles)
Flexor Digitorum Superficialis (clenching a fist)
Opponens Pollicis (Thumb touching little finger)
Interrosei or Intrinsics (Spreading or drawing together the fingers)At the C8 level sensation is present in the hand and all the fingers except the little finger, but grasp is still not possible. It is possible to correct this problem with a surgery that will allow an individual the ability to grasp with the hands, increasing independence.
At the T1 level the individual cannot spread or draw together the fingers but is capable of a weak grasp and dexterity is poor. Surgical approaches can also improve hand function at this level.
PARAPLEGIA
Paraplegia, meaning weakness of some of the limbs, can also apply to a variety of disorders. When the term is applied to spinal cord injury it means a degree of paralysis and lack of sensation in the lower extremities of the body. In paraplegia, the upper extremities are completely functional, and the major functional issue involves ambulation from place to place. The following is a discussion of functional capacities and limitations at each level of the spine below T1.
T2-T6: Intercostal Muscles ("Rib muscles;" Breathing in and out; coughing) The intercostals assist the diaphragm in respiration. Although respiratory capacity is still sufficient for most activities using only the diaphragm, at T6 and above there may be problems of insufficient oxygenation with very heavy exertion. Individuals with injuries at these levels and above might have problems when it is necessary to cough, as with respiratory infections. Ambulation will be accomplished by manual wheelchair for most individuals.
T7-T12: Intercostals (Same as above)
Abdominals (Aid in sitting up, maintaining posture)As the level of spinal lesion is lower in this area of the spine there is less concern with breathing and coughing. At this level it becomes possible for individuals to ambulate for brief periods of time with crutches and long leg braces called KAFOs, or knee-ankle-foot orthoses. However, the amount of exertion required for walking usually limits this to exercise purposes only. Ambulation is primarily by wheelchair.
L1-L4: Iliopsoas (hip muscle that brings the thigh to the chest)
Adductors (Keep the legs together)
Quadriceps (extension and straightening of the knee)
Gluteus Medius (separating the legs and moving the thigh to the side)At this level individuals are capable of functional ambulation for short to moderate distances with KAFOs, although the wheelchair is still usually necessary for long distance ambulation and not abandoned completely.
L5-S2: Gluteus Medius (as above)
Tibialis Anterior (tilting the foot up at the heel; standing on heels)
Gluteus Maximus (alignment of thigh, standing up)
Gastrocneumius (calf muscle, allows for tilting foot down, standing on toes)At this level individuals are usually capable of functional ambulation with shorter leg braces that lock the ankles and feet (ankle foot orthoses, or AFOs). Many individuals may be completely independent of the need to use a wheelchair. Individuals may also be capable of operating an automobile without the use of hand controls, particularly with lesions in the lower part of this section of the spinal cord.
S3-S5: Anal Sphincter (bowel function and fecal continence)
Urethral Sphincter (Bladder control and urinary continence)At the lower end of the spinal column functional problems will be limited to problems with control of the bowel and bladder sphincters. Walking is quite possible, although there can be some loss of sensation in the backs and sides of the legs.
Coccyx
The coccyx or tailbone does not correspond to a spinal nerve. Although injury to the tailbone can be very painful (as anyone who has taken a bad fall on it will attest) if it is confined only to the coccyx there is no damage to the spinal cord.
BOWEL AND BLADDER FUNCTION
All injuries to the spinal cord will cause problems with control of the bowel and/or bladder sphincters. As the level of the spinal cord injury rises, these problems can become more complex as muscles involved in sensing the need for elimination and those assisting in the elimination of wastes are compromised.
At lower levels of injury (T7 to S5) bowel and bladder function tends to be good and can usually be accomplished with abdominal pressure and any residual muscle strength in the sphincters. Dribbling and leakage may be a problem at lower levels due to sphincter weakness, especially in men, and can be controlled by wearing absorbent pads or a simple exterior collection system. In the middle of this range (L1 to L4) the sphincters tend to be tighter and there is less of an issue of dribbling or leakage. At the higher levels sphincters may be so tight and spastic that surgical weakening may be necessary to allow elimination. In these cases external collection or absorbent pads become a necessity.
At T2 through T6, bowel function remains the same as for lower levels of injury. Bladder elimination often requires more effort by stimulation of the sphincter reflex (usually by dilation of the anal sphincter, which tends to trigger the bladder sphincter). Leakage control is more difficult. In women, leakage problems can be severe at these levels and it is not unusual to have an indwelling catheter installed for the elimination of urine, draining into a bag situated in the leg area.
At C6 through T1, stimulation of the bladder reflex becomes a necessity for removal of urine, as are external collection systems for men and indwelling catheters for women
Bowel function usually requires manual stimulation of the anal sphincter with the use of a finger splint.At C5 and above, stimulation of reflexes for bladder and bowel elimination are necessary as in C6 to T1, but must be accomplished with the assistance of an attendant.
SEXUAL FUNCTIONING
One of the greatest areas of adjustment for many individuals who sustain spinal cord injuries is to changes in sexual functioning. Individuals with spinal cord injuries retain the ability to produce sexual hormones, to become sexually attracted to others, to be sexually attractive to others, and usually retain the same strength of sex drive as was present before the injury. Senses of vision, smell, taste and to a varying degree touch remain. The ability to father children or to become pregnant and give birth is also retained. Spinal cord injuries do interfere with movement, sensation, and aspects of physical arousal in both sexes to varying degrees.
All spinal cord injuries are different, and therefore each individual with a spinal cord injury will have differences in their remaining capacity for sexual activity. The following is a discussion of some general expectations for various levels of spinal cord lesion, but it should be remembered that there may be significant variation from individual to individual.
Men: In order to commence and complete the customary act of sexual intercourse men must be able to achieve an erection, emit semen into the urethra and ejaculate the semen. These functions require a coordination of complex nervous impulses which are weak or absent in men with spinal cord injuries, with greater loss of function at higher levels of lesion and less involvement at lower levels of lesion.
Erections may occur via one of three venues: involuntarily by reflex, through physical stimulation, or by psychic imagery. At levels T12 and above, reflex erection is often possible, and mechanical stimulation can also produce and maintain an erection. In the upper lumbar and lower thoracic regions weak erections can be produced by physical stimulation. In the lumbar region, and particularly in lesions of the Cauda Equina, reflex erections are usually weaker than those in higher levels. However, weak psychic erections may be possible with lumbar lesions, which may or may not be suitably strong for vaginal insertion. Emission of semen may occur, but ejaculation is not possible with a spinal cord lesion at any level due to problems with the sphincter. Many men, however, report an "orgasm like" experience associated with a release in sexual tension in the absence of ejaculation.
Surgeries to increase vascular efficiency of the penis have helped some men with lower spinal cord injuries to achieve firmer erections. Other men have found the use of medications such as Viagra helpful in maintaining physical arousal. Still other men may have penile implants surgically installed, which allow for hydraulic fluid to be pumped into the implant and achieve or assist in maintaining an erection.
Fertility remains possible, but the rate is usually under ten percent. Higher rates are seen in men with lumbar and sacral lesions as opposed to those with thoracic and cervical lesions. Artificial insemination methods may be of assistance for men with spinal cord injuries wishing to become fathers.
Women: Women retain more capacity for participation in sexual intercourse, but as with men there is interference with physical arousal and orgasm. Lubrication of the vagina may be inconsistent and may require use of artificial lubrication. Clitoral engorgement may occur by reflex in women in a manner similar to reflex erection in men. All women with spinal cord injuries lose the capacity for contractions of the uterus, vaginal musculature and perineum, equivalent to male ejaculation, but like in many men there is often an orgasmic-like reduction in sexual tension.
Fertility in women is almost always undisturbed by spinal cord injury, and menstruation usually resumes its familiar pattern after the initial trauma of spinal cord injury has resolved. Pregnancy should be carefully medically monitored because of the heightened risk for complications.
In both sexes there will be some degree of loss of the capacity for the gymnastics of lovemaking, which is greater at higher levels of lesion and less at lower levels of lesion. Genital sensation is impaired, although the sensation of areas in the upper thigh might remain and convey a certain feeling of genital stimulation. Individuals with spinal cord lesions may develop heightened sensation in certain areas of the body which are still enervated, such as the shoulders, neck or elsewhere; often these areas become erogenous zones that are capable of being stimulated to the point of an orgasm-like response. Individuals will also retain the capacity for oral stimulation and, in persons with paraplegia and lower levels of quadriplegia, manual stimulation of a partner.
Individuals with spinal cord injuries, both men and women, may often be looked on as individuals that have lost their sexual roles and functions. In reality, no one with a spinal cord injury (or any other disability) loses their capacity to develop relationships of a sexual nature or to have sexual relations with other persons. The behaviors and activities involved in sexual activity may require modification. Individuals who work with persons with spinal cord injuries should recognize this fact, and information and referral for counseling on sexual matters should be a resource that rehabilitation counselors are able to provide to consumers when appropriate.
COMPLICATIONS OF SPINAL CORD INJURY
Spinal cord injuries are wrought with complications that can affect a wide variety of body systems. Infections of the respiratory and urinary tract are very common, and prior to the development of antibiotics in the 1940s most persons who sustained spinal cord injuries, particularly medium and higher level lesions, quickly succumbed to these complications-it was rare to see someone using a wheelchair before 1940. Blood clots can form in the legs due to lack of movement and pooling of blood; contractures (fused stiffening) of joints can develop if they are not periodically moved through a complete range of motion; osteoporosis can develop in the bones leading to fractures; any of a host of other complications can develop with spinal cord injury.
Two complications of spinal cord injury are particularly problematic and deserve special mention.
Autonomic Dysreflexia affects individuals with lesions at T6 and above is a sudden, massive rise in blood pressure accompanied by profuse sweating and a pounding headache in the middle of the forehead, goosebumps, and swelling of the nasal membranes. The cause is often the backing up of a catheter or urine drainage system allowing urine to back up into the bladder and kidneys; however, certain sensations, particularly painful stimulation, can cause the problem in some individuals. Persons who give care or have frequent contact with individuals with spinal cord injuries need to recognize the signs of an attack of autonomic dysreflexia, which is a medical emergency. The extremely high rise in blood pressure can cause sudden massive strokes or heart attacks. Medical attention should be sought immediately, and catheters and drainage systems for urine should be immediately checked to make sure they are not blocked or otherwise constricted. Placing the individual in a sitting or standing position is often helpful in bringing about a drop in blood pressure.
Decubitus Ulcers, also called Bed Sores or Pressure Sores, are the result of unrelieved pressure on bony protuberances under the skin for long periods of time, leading to break down of skin and formation of ulcers. Individuals who do not have paralysis or lack of sensation naturally and usually unconsciously shift the body position to relieve pressure brought on by sitting or lying down, even in sleep. Persons with spinal cord injuries lose the capacity to sense that there are problems and may lose the capacity to spontaneously shift body position due to paralysis. Therefore, areas of the body in constant contact with a bed or wheelchair are particularly susceptible to decubitus ulcers.
To demonstrate the effect of pressure on the skin, take a pair of eyeglasses or a clear drinking glass and press it against one of your knuckles. The skin in the knuckle will become pale as blood is forced from the area by the pressure. While this sensation is not painful, if the pressure remains for a considerable period of time you would feel pain in the area, and eventually would develop a decubitus ulcer there.
Decubitus ulcers are best treated through prevention. Persons with spinal cord injuries are trained to shift position or raise themselves in wheelchairs periodically to prevent ulceration. Beds with water mattresses or very soft padding may be helpful in preventing ulcer formation; there are also certain other types of bed frames that can help distribute body weight more evenly. Once decubitus ulcers develop they are very difficult to heal, especially if nervous and vascular activity in the area has been compromised.
REHABILITATION CONSIDERATIONS
Individuals with spinal cord injuries may have a variety of different functional problems that are more problematic as the level of the lesion is higher. Brain function is uncompromised, and the individual will be capable of functioning at an intellectual level equal to that observed prior to the injury. Therefore, long term training capacity would not be compromised by the injury, unless there is a particularly grim prognosis or lack of intellectual potential carrying over from before the injury.
Schooling should be encouraged whenever feasible. Most individuals with spinal cord injuries will be capable of performing only sedentary (seated) work or, at most, work with light walking and lifting requirements. Because the best occupations in these physical demand categories require academic training, the more education an individual with a spinal cord injury is capable of completing, the wider his or her vocational options will become. Individuals who were employed in sedentary and light occupations prior to the injury may be capable of returning to their previous jobs through work site modification.
Ambulation is a major functional requirement to match or modify in a vocational situation. Persons who use AFOs may be capable of performing work that requires significant walking on level surfaces or some stair climbing, but this individual will need to avoid stooping, bending, climbing of ladders and other structures and prolonged standing. Individuals who use KAFOs would best be placed in work that can be performed in a seated position with occasional standing and walking for only the shortest of distances on level surfaces. Persons who must use the wheelchair exclusively for ambulation will only be able to perform work activities that can be accomplished in the wheelchair.Accessibility of the school room or work site is a crucial consideration. The individual must be capable of getting in and out of his or her desk or work station. This not only involves matters such as ability to get in and out of a building but also issues of parking, terrain from the parking site to the building entrance, and even snow and ice removal in inclement weather. If persons with spinal cord injuries are unable to drive, alternative transportation to and from the school or work site must be arranged. Additional considerations include accessibility of break rooms, cafeteria facilities, and especially rest rooms. Individuals with spinal cord injuries will need to be able to efficiently enter rest rooms and likely will desire privacy, especially if there is a need to attend to drainage bags, catheters, or absorbent padding.
Environmental considerations must also be considered in placement of those persons with lesions above T6. At this level and above there are problems with coughing. Therefore, dusty environments or environments with noxious fumes should be avoided. Individuals with cervical and thoracic lesions also tend to have problems with regulation of body heat due to problems with perspiration and dilation of small blood vessels; therefore, the work environment should be effectively climate-controlled. Individuals with lesions at C7 and below might also be capable of performing some work out of doors, provided that wheelchairs are equipped with appropriate tires and devices for outdoor use.
Assistive technology applications are an important consideration in rehabilitation for persons with spinal cord injuries. With individuals with paraplegia, usually this may consist of nothing more than finding the right wheelchair. As the level of spinal cord injury rises, the extent of assistive technology application becomes greater. Persons who have quadriplegia may need a wide variety of devices to allow them to perform common tasks at work or school, such as answering telephones, taking notes, or typing papers and reports. In the home environment, a variety of assistive devices may also be necessary to assist the individual in activities of daily living. Accessibility of the home or apartment is another consideration that may require extensive rehabilitation intervention.