Chapter 10
Nerves, Muscles, and Bones
A number of different conditions can affect your nerves, muscles, and bones after spinal cord injury. The sections in this chapter will describe each situation, its advantages and disadvantages, and what you can do about it.
SPASTICITY
When some spinal cord nerve cells are disconnected from your brain, they gradually develop exaggerated activity due to increased reflexes. Even simple things like touching or irritation to your skin, stretching muscles, or stretching your bladder may cause a reflex contraction of your muscles that you cannot control. One common type of reflex muscle contraction seen after spinal cord injury is a rigid straightening of the knees and pointing of the toes (extensor spasms). Another type is bending of the hip and of the knee (flexor spasm).
Advantages of Spasticity
- Increases in spasticity can warn you of any pain or problem in those areas where you cannot feel (e.g., urinary tract infection, pressure sore).
- Spasticity helps maintain your muscle size and bone strength.
- Spasticity helps promote circulation of your blood.
- You may learn to use your spasticity functionally; for example, using extensor spasms to help transfer or to walk with braces.
Disadvantages of Spasticity
- It may interfere with sleep, driving, sex, walking with braces, etc.
- It may cause scraping of your skin and result in skin breakdown.
- It may cause limited joint movement.
See the section in this chapter on contractures.
What to Do
Most spasticity can be tolerated to enable you to benefit from its advantages. Some ways to control spasticity and prevent complications include:
- Performing daily range-of-motion exercises to help reduce spasticity.
- Avoiding stimulation that you find aggravates the spasticity (such as fast movements or certain body positions).
- Asking your therapists about the use of padded straps and splints that can help control spasticity.
- Protecting your feet and legs from striking sharp or hard objects due to a spasm (such as against your wheelchair during transfers).
- Taking a warm (not hot!) bath or shower.
- Trying to relax or reduce your level of stress.
If spasticity is interfering with sleep, driving, or other functioning, you should discuss treatment options with your SCI physician. Treatment alternatives include:
- Medications, although all have side effects and none will eliminate spasticity.
- Injections of specific medications into muscle or nerve to reduce spasticity.
- Surgery to nerve roots or the spinal cord.
- Baclofen pump - surgical implantation of a device that delivers medication directly to the spinal canal.
Remember that significant increases in spasticity may be a sign that something is wrong in a part of your body where you do not have sensation. Such increases in spasticity might be a warning of a urinary tract infection, a pressure sore, a kidney stone, appendicitis, an ingrown toenail, or almost any problem. Notify your SCI physician, nurse, or therapist if you notice a significant increase or decrease in spasticity.
ATROPHY AND CONTRACTURES
Atrophy is the shrinking of muscle size when the muscle is not used. Some spinal cord injuries result in more, some in less, atrophy. A contracture (con-TRACK-churr) is the tightness of tissues around joints and in muscle that limits movements and function.
Contractures can be a serious problem, but they are preventable. If range-of-motion exercises are neglected, then contactures can permanently limit joint movements. Contactures can interfere with transfers or daily activities. They can also change your posture, which can lead to pressure sores. In some individuals, tightness of some muscles of the hand is actually planned to improve the grip, called tenodesis (ten-oh-DEE-siss).
Atrophy generally is not a medical problem.
Treatment
Contractures can be prevented by moving joints through their full range of motion regularly. Joints in body areas where the muscles do not work must be moved manually by yourself or by an attendant. Your therapists will instruct you in the range-of-motion exercises most important for you and how they should be performed. Shoulders, elbows, hips, knees, and ankles are the joints that usually are most important in preventing contractures. If you have severe spasticity, then range-of-motion exercises may be particularly important, and you may need to do them several times a day.
Atrophy is generally not treated directly. Instead, you will learn to avoid any long-term pressure on bony areas (such as buttocks or shoulders) to prevent pressure sores. Atrophy can sometimes be prevented by electrical stimulation performed two or three times per day. However, each muscle that is to be increased in size must be stimulated, and this can become very time consuming and costly. Unless some functional movement returns or unless this electrical stimulation is medically necessary, this strengthening is not generally done with SCI patients.
NEUROGENIC HETEROTOPIC OSSIFICATION
Neurogenic heterotopic ossification (nurr-oh-JENN-ick HETT-air-oh-TOP-ick OSS-ih-fih-KAY-shun), or NHO, is the growth of a knot-like piece of bone in the soft tissues of your body below the level of your spinal cord injury. This bone is formed in between your muscles, often near a joint. It can affect all joint areas below the level of your spinal cord injury. It most commonly affects the areas of your hips, knees, and elbows. (See figure 10.1.)
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FIGURE 10.1. Neurogenic Heterotopic Ossification
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Ultimately the bone growth stops on its own. It usually will appear on an X-ray about 4 to 10 weeks after the process begins. The whole process ends in about 8 to 30 months, leaving behind a chunk of complete, honest-to-goodness bone. It is just like any other bone in your body except that it serves no particular function, and it can often cause problems in joint movement.
The Cause
Unfortunately, the cause of this condition is unknown. It does not occur in all people with SCI. No one knows why some patients get it and others do not. For some reason, your bone cells show up in soft tissue, where they mature and harden.
Some things that may contribute to and start this process are probably related to changes in your body due to your injury. It may have something to do specifically with changes in blood flow, hormones, or the chemistry in the area where the NHO starts. Some people feel that overly vigorous range-of-motion exercises can tear the tissues and cause the problem. Other theories are that local bleeding in the area caused by an injury or tearing leads to the deposits of bone cells.
Symptoms
- Decreased joint range of motion - this may develop slowly or quickly
- Swelling
- Redness
- Increased skin temperature over this swollen region
Other Causes of These Symptoms
These other conditions can have the same types of symptoms and must be evaluated:
- An infection in the area
- A broken bone
- Bleeding into the muscle
- Deep vein thrombosis (throm-BO-siss)(DVT)
Your doctor may do different tests to find out which condition is actually causing the symptoms. DVT must be ruled out by your doctor immediately, as this is a life-threatening situation and must be treated promptly. See the chapter on Circulation.
Effects
The worst complications of NHO are severely decreased range of motion and contractures. These greatly interfere with your self-care and mobility and could cause problems with sitting, lower extremity dressing, transfers, bathing, and walking.
Testing for NHO
Three tests are used to evaluate and follow neurogenic heterotopic ossification:
- Alkaline phosphatase (AL-kah-line FOSS-fah-taze): The level of alkaline phosphatase in your blood stays high throughout the period of active bone formation. It eventually drops back to normal values when the NHO stops growing.
- X-rays: X-rays are used to confirm the location of the NHO and to estimate how mature the new bone is. An X-ray cannot tell how long it has been there.
- Bone scan: A bone scan is the best test for diagnosing NHO. It can detect NHO about four weeks before an X-ray can.
Treatment
There is no one, successful treatment of NHO. A medication called etidronate disodium (or Didronel®, DID-row-nall) is sometimes prescribed to try to prevent the NHO from starting or continuing.
Your doctor will know that the NHO has fully matured when your alkaline phosphatase returns to normal again and a bone scan shows no more actively growing bone. The bone may then be removed surgically to improve your joint movement. If the bone does not cause you any movement problems, your doctor may decide to just leave it there.
Help through Range of Motion
We feel that full, gentle passive or active assisted range-of-motion exercises help rather than hurt. You should try to maintain the range that you have.
OSTEOPOROSIS OR WEAK BONES
Osteoporosis (OS-tea-oh-poor-OH-siss) is loss of calcium and phosphorus from bone. It is common following spinal cord injury. Bones that usually are kept strong through muscle activity and walking can no longer get what they need. Osteoporosis weakens the bone and makes it easier to break and slower to heal.
Osteoporosis in People with SCI
There are no proven treatments for reversing or preventing osteoporosis, although some experimental treatments are being tested. The primary treatment is to prevent fractures. So extra precaution should be used to prevent falls or striking your leg against an object during transfers. Follow the range-of-motion guidelines from your therapists to avoid putting excessive stress or pressure on bones. Walking with braces may help to limit the amount of osteoporosis that develops in the legs.
PROTECTING YOUR UPPER EXTREMITIES
Your upper extremities--your shoulder, elbows, wrists, and hands--are important. Using a wheelchair, especially a manual wheelchair, requires more work with your arms than they were used to when you walked. Over-use injuries can occur but are less likely if you follow some simple advice:
- Cuts, Blisters, and Abrasions on Your Hands: Wheelchair-push gloves can be worn to protect your hands. They are not essential if you have paraplegia, but if you cannot feel all or part of your hands, protective gloves are a good idea.
- Carpal Tunnel Syndrome: This is an inflammation of the tendons leading into the hand that can cause pressure on the nerve entering the hand, which will result in a painful or numb hand. This is an over-use syndrome and prevention is the best cure--avoid repetitive motion of the wrist, especially flexion (bending your wrist down) or extension (bending your wrist up).
- Ulnar Nerve Compression: The ulnar nerve courses very close to the surface at the elbows. (This is your "funny bone"--not so funny when you bang it). Avoid leaning on your wheelchair armrests or desktops. If you do this for balance, talk to your therapist about your wheelchair set-up for better trunk support.
- Tennis Elbow (Lateral Epicondylitis): This is an inflammation of the extensor tendons of the wrist and fingers (the ones you use in straightening your fingers and raising your wrist). Avoid excessive repetitive motion.
- Shoulders: Primary issues at the shoulders are biceps tendinitis and impingement syndrome. Biceps tendinitis is caused by over-use of the muscle--often from overhead reaching activities. Impingement syndrome is more complex. Both problems relate to muscle imbalance, poor posture, and often poor habits in transfers.
Prevention
Shoulder protection programs should include anterior stretching of the anterior shoulder, posterior shoulder and rotator cuff strengthening, and avoidance of impingement patterns. Impingement pattern means weight bearing with the hand at or above the height of the shoulders. All transfers should be done with hands down--as low as possible--with a forward bent posture, allowing counterbalance with your head and upper body to decrease the weight bearing on your shoulders. Never use an overhead trapeze or overhead grab bar. Your wheelchair should be set up by your therapist to optimize your posture and push mechanics. See your physical therapist for simple exercises that should be part of your daily routine if you push a manual wheelchair and do independent transfers.
Pain is an early indicator. If you have pain in one of your joints or part of your shoulder or arm and you didn't do something obvious to cause it, you should contact a therapist familiar with spinal cord injury to help you troubleshoot and solve the problem. Early intervention is best.
Other Upper Extremity Issues
- Edema: Especially for people with high quadriplegia, swelling of the hands can be a problem. This makes your hands more vulnerable to skin breakdown. Elevation and compression are the best management, combined with daily range of motion. Consult your occupational therapist for more advice on management. Chronic edema can be a symptom of other problems. When elevation and compression fail to reduce the swelling, contact your doctor.
- Shoulder Subluxation: Again, this is an issue primarily for people with high quadriplegia without normal shoulder musculature. The problem here is gravity: the weight of the arm pulls the shoulder out of the socket. The result can be pain. The best prevention and management is to support the arm, so do not allow your arm to dangle, and do not allow anyone to pull your weight with your arms.
- Elbows: Support your arm, not your body, through your elbows. Consult your therapist for proper positioning.
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Nerves, Muscles, and Bones