NEUROMUSCULAR DISORDERS: ALS, GUILLIAN BARRÉ AND MYASTHANIA GRAVIS

Transcription

1 GUILLIAN BARRÉ AND MYASTHANIA GRAVIS by Helen Schaar Corning RRT, RCP V7106 HC 02 RC Educational Consulting Services, Inc. P.O. Box 1930, Brockton, MA (800) 441-LUNG / (877) 367-NURS

2 BEHAVIORAL OBJECTIVES UPON COMPLETION OF THE READING MATERIAL, THE PRACTITIONER WILL BE ABLE TO: 1. Describe how neuromuscular weakness can affect the ventilatory muscles. 2. Explain the function of the neuromuscular junction. 3. Describe the function of the neurotransmitter acetylcholine (ACh). 4. Explain how to manage respiratory muscle weakness. 5. Name the most common neuromuscular diseases. 6. Describe the characteristics of Amyotrophic Lateral Sclerosis (ALS). 7. List the signs and symptoms of ALS. 8. Outline typical testing for ALS. 9. Summarize the typical treatment plan for ALS. 10. Describe the characteristics of Guillain-Barré Syndrome. 11. List the signs and symptoms of Guillain-Barré Syndrome. 12. Outline a typical treatment plan for Guillain-Barré Syndrome. 13. Describe the characteristics of Myasthenia Gravis. 14. List the signs and symptoms of Myasthenia Gravis. 15. Summarize the testing and monitoring of Myasthenia Gravis. 16. Outline a typical treatment plan for Myasthenia Gravis. 17. Explain Polio and Post Polio Syndrome (PPS). 18. List the muscular dystrophies. 19. Explain myopathies and myopathic disease. 20. List other neuromuscular disorders. 2 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

3 COPYRIGHT 2010 BY RC EDUCATIONAL CONSULTING SERVICES, INC. AUTHORED (2010) BY HELEN SCHAAR CORNING, RRT, RCP ALL RIGHTS RESERVED This course is for reference and education only. Every effort is made to ensure that the clinical principles, procedures and practices are based on current knowledge and state of the art information from acknowledged authorities, text and journals. This information is not intended as a substitution for diagnosis or treatment given in consultation with a qualified health care professional. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 3

4 TABLE OF CONTENTS INTRODUCTION... 6 THE NEUROMUSCULAR JUNCTION... 6 NEUROMUSCULAR WEAKNESS AFFECTING THE MUSCLES OF VENTILATION... 8 AMYOTROPHIC LATERAL SCLEROSIS (ALS) OR LOU GEHRIG S DISEASE DESCRIPTION SIGNS AND SYMPTOMS TESTING TREATMENTS GUILLAIN-BARRÉ SYNDROME DESCRIPTION SIGNS AND SYMPTOMS TESTING TREATMENTS MYASTHENIA GRAVIS DESCRIPTION SIGNS AND SYMPTOMS TESTING TREATMENT OTHER NEUROMUSCULAR DISORDERS POLIO DESCRIPTION This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

5 SIGNS AND SYMPTOMS PREVENTION NOTES ON POST POLIO SYNDROME MUSCULAR DYSTROPHY MUSCULAR DYSTROPHIES MYOPATHIES MULTIPLE SCLEROSIS CONCLUSION SUGGESTED READING AND REFERENCES POST TEST...25 COURSE EVALUATION.29 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 5

6 INTRODUCTION N euromuscular disorders and diseases encompass a broad range of illnesses that impair the function of muscles and/or the nerves that control the muscles. Myopathies are muscle diseases that cause progressive weakness and deterioration of the muscles. The diseases ravage the body, as they cause the muscles to break down. This causes multiple debilitating symptoms that range from mild to severe pain, and even to respiratory insufficiency and respiratory failure. However, the prognosis for many patients afflicted by neuromuscular disease has improved over time, because advancements in medical technology continue to aid in treatments that increase the quality of life, and extend life expectancy. Some neuromuscular disorders and diseases are genetic, while others develop over the lifetime due to viruses or other causative factors. This course details the most common neuromuscular disorders seen in respiratory care, with a brief overview of others. Each of the disorders/diseases are listed individually with the description, signs and symptoms, tests, and treatments. THE NEUROMUSCULAR JUNCTION T he neuromuscular junction (the neuromuscular synapse) is involved in impulse transmission. The neuron is the nerve cell body. Axons carry impulses away from the neuron. Dendrites carry impulses to the neuron. Axons can also connect with other nerves or with muscle cells. The nerve terminal (myelinated axon) penetrates the surface of the muscle receptor cell. The penetrating fingers of the nerve cells are the nerve terminals. The nerve terminals contain mitochondria which produce energy and contain acetyl-coa. Inside the nerve cell cytoplasm exists the Acetyl-CoA and choline, which react in the presence of acetylcholine transferase; thus forming acetylcholine (ACh). ACh is a neurotransmitter that sends electrical impulses across synapses between nerve cells, and from motor neurons to muscle cells, causing the muscle cells to contract. 6 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

7 Picture 1. The Neuromuscular Junction. Courtesy of: University of Miami. When the electrical impulses reach the nerve ending, the nerve cell releases acetylcholine, which passes across the synapse and bonds chemically with a receptor molecule in the membrane of a nerve cell. The bonding alters the polarity and permeability of the membrane, thus allowing the nerve impulse to be transmitted. The acetylcholine effect can be neutralized by an enzyme, like cholinesterase. The cholinesterase decomposes acetylcholine through the process of hydrolysis, and the muscle then relaxes. There are agents that affect the neuromuscular junction. These are listed here: Anticholinesterase: Inhibits the normal breakdown of ACh into acetate and choline by the enzyme acetylcholine esterase. Curare: Blocks the acetylcholine from reaching the muscle receptor sites. Botulism toxin: Blocks acetylcholine release, or blocks binding at the site of release. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 7

8 Succinylcholine: Intensifies the depolarization effect of acetylcholine at the muscle receptor site. Picture 2. Acetylcholine. Courtesy of: Dementia Guide When the nerve cells, or neurons are not functioning properly, the muscles can weaken and waste away. Some signs are dyspnea, fatigue, twitching, cramps, aches and pains, joint problems, problems with movement, and paralysis. Neuromuscular disorders can also affect the heart and respiratory system, causing respiratory insufficiency or respiratory failure. NEUROMUSCULAR WEAKNESS AFFECTING THE MUSCLES OF VENTILATION T here are many neuromuscular problems that cause pulmonary dysfunction. This is characterized by respiratory muscle weakness, hypoxemia, atelectasis, ventilatory insufficiency, and ventilatory failure. Maintaining normal ventilation is dependent upon properly functioning components of the neuromuscular system. Any disease that affects the nerves, muscles, brain, or thoracic cage can lead to respiratory insufficiency. The pulmonary problems associated with neuromuscular disease include: hypoventilation hyperventilation 8 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

9 atelectasis hypoxemia sleep apnea pulmonary hypertension cor pulmonale The neuromuscular components of the pulmonary system include: (See Picture #3) Cortex and Upper Motor Neurons (allows conscious alterations of the breathing pattern) Brainstem (pons and medulla; automatic respiration) Anterior Horn Cells and Lower Motor Neurons Spinal Cord Peripheral Nerves Neuromuscular Junction Muscles This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 9

10 Upper motor neurons Tongue Lower motor neurons Axon bundies Arm muscle Rib muscles in breathing Spinal lower motor neurons Leg muscles Picture 3. Neuromuscular components. Courtesy of: University of Edinburgh. Patients with respiratory muscle weakness due to neuromuscular problems may initially have symptoms like exertional dyspnea, fatigue, orthopnea, or accessory muscle use. These symptoms occur because the muscles involved in ventilation are not capable of generating and maintaining sufficient ventilation. The patient with progressive respiratory muscle weakness may display a rapid, shallow breathing pattern. Those with poor inspiratory lung function may display orthopnea and may prefer sleeping in a semi-fowler to high-fowler position. They may also have diminished power and volume of the voice. The decline in expiratory lung function is displayed by poor cough and poor secretion clearance ability. The progressive muscle weakness can lead to cor pulmonale, insufficient ventilation and hypercapnia. Neuromuscular weakness in the pulmonary system is characterized by the inability to generate and maintain normal respiratory pressures. These patients will display a restrictive ventilatory defect with decreased vital capacity (VC), total lung capacity (TLC), and forced expiratory volume in one second (FEV1). The PImax will reflect decreased inspiratory muscle strength, and the PEmax will reflect decreased expiratory muscle strength. The decrease in respiratory muscle strength typically begins with the rapid shallow breathing pattern. Progressive inspiratory muscle weakness can eventually lead to hypoventilation and hypercapnia. Also the pattern of shallow breathing leads to atelectasis, hypoxemia, and ventilation/perfusion mismatch. Neuromuscular weakness can result in respiratory failure, but current therapeutic modalities can delay or stop the onset of ventilatory failure for short to indefinite periods of time. 10 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

11 Advancements in modern medicine continue to improve the quality and duration of life for those with neuromuscular weakness. One of the most common therapies for neuromuscular weakness is ventilatory support, including BIPAP. In mild cases, the patient may only need ventilatory support for a few hours per day, or only while sleeping. Here, modern medicine helps the patient enjoy a better quality of life, by improving ventilation with ventilatory support in the least restrictive manner possible. PAP, EZPAP, and PEP therapies are also useful for some cases of neuromuscular weakness, as these therapies can aid in secretion clearance, and reversing atelectasis. Depending on the type of disorder, medications like bronchodilators can help relieve dyspnea. Monitoring of the condition is also important, utilizing the negative inspiratory force (NIF) and vital capacity (VC) measurements. Therapies are detailed further in each of the neuromuscular diseases in this course. AMYOTROPHIC LATERAL SCLEROSIS (ALS) OR LOU GEHRIG S DISEASE Description: A myotrophic Lateral Sclerosis is also referred to as ALS or Lou Gehrig s Disease. This is a degenerative neuromuscular disease. ALS is characterized by progressive degeneration of the brain and spinal cord motor neurons. The onset of ALS is insidious, with muscle weakness or stiffness as early symptoms. There is progressive atrophy of the hands, forearms, and legs, as well as those that control vital functions such as speech and swallowing. Eventually withering of muscles (See Picture #4) throughout the body occurs, including the muscles of ventilation. Therefore, intervention with respiratory therapeutics is necessary once in the stage of ventilatory insufficiency. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 11

12 Normal Spinal Neuron Diseased Spinal Neuron Normal Nerve Fiber Affected nerve fiber Normal skeletal muscle Wasted skeletal muscle Picture 4. Normal and Diseased Spinal Neuron. Courtesy of: Health A To Z ALS is not a contagious disease. It occurs worldwide with no racial, ethnic or socioeconomic boundaries, and can strike anyone. In 1991, researchers linked familial ALS to chromosome 21. In 1993 researchers identified a defective SOD1 gene on chromosome 21 as responsible for many cases of familial ALS. Later, studies revealed over 60 mutations (structural defects) in the SOD (superoxide dismutase) enzyme which alters the enzyme's ability to protect against free radical damage to motor neurons. These studies continue to open possibilities for future therapies or strategies to effectively mediate both familial and sporadic ALS. More research is necessary, and other gene involvement on other chromosomes have not been ruled out. The life expectancy of an ALS patient averages about two to five years from the time of diagnosis, however, this disease is quite variable and many people live with quality for five years and more. More than 50% of all people with ALS live more than three years after diagnosis. About 20% of people with ALS live five years or more, about 10% survive more than ten years, and about 5% live 20 years. There are also people in whom ALS has stopped progressing, and a small number of people in whom the symptoms of ALS reversed. Approximately 5,600 people in the U.S. are diagnosed with ALS each year. The incidence of ALS is two per 100,000 people, and it is estimated that as many as 30,000 Americans may have the disease at any given time. 12 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

13 Signs and Symptoms: The signs and symptoms of ALS include: Muscle weakness, muscle atrophy, decreased muscle strength, hypoventilation, ineffective cough, atelectasis, pneumonia, hypoxemia, hypercapnia, respiratory insufficiency, and respiratory failure. Testing: Tests used in diagnosis include: EMG (electromyography). This procedure produces a continuous recording of the electrical activity of the skeletal muscles. It is used in the diagnosis of certain nerve and muscle disorders. With the EMG, an electrode is inserted into the muscle or placed on the skin. The recording is then viewed on an oscilloscope that displays the changes in the electrical current on a fluorescent screen. Picture 5. Electromyography. Courtesy of: OC Neurology Medical Center NCV (nerve conduction velocity) Spinal tap Neurological exam Laboratory testing PFT (pulmonary function testing). The PFT typically reveals the following problems: restrictive disease with decreased FVC, decreased pressures including decreased PImax, and decreased PEmax. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 13

14 Treatments: Treatments include: Prevent respiratory complications and provide ventilatory support via BIPAP or full support if required. Provide oxygen as needed. Provide education and assistance with secretion clearance, cough techniques, and assisted cough. The first drug utilized to alter the course of ALS was approved in 1995 by the FDA. Riluzole (Rilutek ) is an antiglutamate drug, which has shown scientifically to prolong the life of ALS patients by at least a few months, and slow the progression of ALS. GUILLAIN-BARRÉ SYNDROME Description: G uillain-barré syndrome is also known as Inflammatory Demyelinating Polyneuropathy. A typical characteristic of Guillain-Barré syndrome is an ascending (from feet upward) muscle paralysis due to simultaneous malfunction of many nerves throughout the body, including nerves of the autonomic nervous system. (Note: There does exist a rare variant form that is a descending paralysis.) Guillain-Barré Syndrome is rare, and can be acute or chronic. It can be a short-term illness or last indefinitely. Polyneuropathy is idiopathic. The presumed cause is an autoimmune reaction. The body's immune system attacks part of the peripheral nervous system, the myelin sheath that surrounds the axon of nerves. There are many possible causative factors of acute polyneuropathy, including: post-infection, heredity, hypothyroidism, liver failure, kidney failure, alcoholism, anemia, malnutrition, excess amounts of vitamin B6, certain cancers, toxic substances, and certain drugs like anticonvulsants, antibiotics, sedatives, sulfonamides, and chemotherapy drugs. It should be noted that this syndrome occurs more frequently in diabetics. This syndrome occurs most often after an infection, a flu-like illness, surgery, or an immunization. Usually Guillain-Barré occurs within 1 to 6 weeks after the patient has had symptoms of an illness, respiratory or viral infection, or post surgery. Occasionally vaccinations will trigger the syndrome. Signs and symptoms: The first symptoms of this disorder include varying degrees of weakness or tingling sensations in the legs. In many instances, the weakness and abnormal sensations spread to the arms and upper body. These symptoms can increase in intensity until the muscles cannot be used at all and the patient is almost totally paralyzed. This can progress rapidly to become a life-threatening medical emergency, requiring mechanical ventilation. Then, there are also mild cases that resolve spontaneously over several months. Symptoms usually begin within 1 to 6 weeks after an infection, illness, or surgery. Symptoms include pins-and-needles sensation, numbness, burning pain, and loss of sensation, with possible dysphagia and aspiration. This can eventually lead to muscle paralysis; including paralysis of the diaphragm and muscles of ventilation, causing respiratory failure. 14 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

15 Most patients do recover from even the most severe cases of Guillain-Barré syndrome, although some will continue to have some degree of weakness for years. No one yet knows why Guillain- Barré strikes some people and not others with similar medical status, and it is still unknown exactly what sets the disease in motion. Scientists do know the body's immune system begins to attack the body itself, causing what is known as an autoimmune disease. Guillain-Barré is called a syndrome rather than a disease because it is not clear that a specific disease-causing agent is involved. Testing: Electromyography, nerve conduction studies, and analysis of cerebrospinal fluid via lumbar puncture (increased protein in CSF is indicative). Also, blood and urine laboratory testing. (These can be useful in ruling out or detecting diabetes, kidney failure, or thyroid disorder). Reflex tests are also used, such as the knee jerk, where reflexes are usually lost. Treatments: While there is no known cure for Guillain-Barré syndrome, therapies can lessen the severity of the illness and accelerate the recovery in most patients. The most critical part of the treatment for this syndrome consists of keeping the patient's body functioning during recovery of the nervous system. This can sometimes require placing the patient on a ventilator, or other machines that assist body function. It is important to monitor pulmonary mechanics, especially the Vital Capacity (VC) and Negative Inspiratory Force (NIF). Decreasing respiratory muscle strength can be observed and documented with the VC and NIF. When indicated, ventilatory support can be initiated. BIPAP or full ventilatory support can be utilized depending on the patient s respiratory status. Nutritional support and physical therapy are also important in the care plan. Other treatments options include: corticosteroids, immunosuppressants, plasmapheresis and high-dose immunoglobulin therapy. Plasmapheresis can reduce the severity and duration of the Guillain- Barré episode. In high-dose immunoglobulin therapy, doctors give intravenous injections of the proteins that in small quantities, the immune system uses naturally to attack invading organism. Research has found that giving high doses of these immunoglobulins, derived from a pool of thousands of normal donors, to Guillain-Barré patients can lessen the immune attack on the nervous system. Early and prompt treatment promotes faster improvement. The patient may need some ventilatory support for an indefinite period of time ranging from days to years. Some residual muscle weakness can also exist for years. Research is concentrating on finding new treatments and refining existing ones. Scientists are also looking at the workings of the immune system to find which cells are responsible for beginning and carrying out the attack on the nervous system. The fact that so many cases of This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 15

16 Guillain-Barré begin after a viral or bacterial infection suggests that certain characteristics of some viruses and bacteria may activate the immune system inappropriately. Researchers are attempting to identify those characteristics. Neurological scientists, immunologists, virologists, and pharmacologists are all working collaboratively to learn how to prevent this disorder and to make better therapies available when it strikes. MYASTHENIA GRAVIS Description: M yasthenia Gravis is an autoimmune disease involving extreme weakness of some muscles, caused by the blocking of the receptors for acetylcholine, the neurotransmitter that causes muscular contraction. This is a chronic disease marked by progressive weakness and abnormally rapid fatigue of the voluntary muscles. Myasthenia Gravis weakness usually occurs in a descending manner, from the face downward. Most frequently, the muscle weakness begins in the face and the throat, and then the muscles of ventilation, descending to the muscles that affect the ability to walk. Drooping eyelids are one common characteristic of the disease. There can be fluctuating weakness of the voluntary muscle groups. MG is not thought to be a hereditary disease. Picture 6. Neuromuscular Junction. Courtesy of: Shelfield Sports And Community College 16 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

17 The prevalence of Myasthenia Gravis in the United States is estimated to be about 20/100,000 population. However, it is probably under-diagnosed and the prevalence may be higher. Myasthenia Gravis occurs at any age, in both males and females, in all races. Myasthenia Gravis often affects women between the ages of 20 and 30, but after age 40, it afflicts more men than women. Myasthenia Gravis is characterized by the presence of antibodies in the blood that destroy muscle-cell sites for the reception of acetylcholine molecules. There is reduced transmission of nerve impulses at the neuromuscular junction, with a possible link to excess acetylcholinesterase, or lack of acetylcholine. Acetylcholine normally transmits signals between nerves and muscles (See Picture #2), so when its receptors are destroyed it cannot induce muscle contractions. Antibodies are proteins that play an important role in the immune system. They are normally directed at foreign proteins (antigens) that attack the body. The foreign proteins include bacteria and viruses. Antibodies help the body to protect itself from these foreign proteins. For unknown reasons, the immune system of the person with Myasthenia Gravis makes antibodies against the receptor sites of the neuromuscular junction. Abnormal antibodies can be measured in the blood of many people with MG. The antibodies destroy the receptor sites more rapidly than the body can replace them. Muscle weakness occurs when acetylcholine cannot activate enough receptor sites at the neuromuscular junction. Signs and Symptoms: Patients complain of weakness and fatigue, especially with exertion. Early signs include facial muscle weakness, and ocular muscle weakness, droopy eyelids, blurred or double-vision, difficulty chewing, dysphagia (impaired swallowing), and dysphasia (including slurred speech). Weakness in the arms and legs, chronic muscle fatigue, and difficulty breathing. This can also lead to respiratory insufficiency and respiratory failure. Testing: A complete medical and neurological evaluation is performed, along with a number of other tests. Diagnostic testing includes: Tensilon test - The Tensilon (edrophonium chloride) test is performed by injecting into a vein. Tensilon is a short-acting anticholinesterase drug. If tensilon worsens the patient s condition, it is a cholinergic crisis. If the patient s condition improves temporarily with tensilon, it is a myasthenic crisis. Improvement of strength immediately after the injection provides strong support for the diagnosis of Myasthenia Gravis. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 17

18 Acetylcholine Receptor Antibody - A blood test for the abnormal antibodies can be performed to asses for presence or absence. About 85% of Myasthenia Gravis patients have this antibody and, if detected, it is an assured diagnosis. Anti-Musk Antibody testing this test can be used for the other 15% who seronegative (those who have tested negative for the acetylcholine antibody). In those with suspected Myasthenia Gravis, who are seronegative, another 40-70% test positive for the Anti- Musk antibody. The remaining patients have an unidentified antibody causing their Myasthenia Gravis. Electromyography The EMG (See Picture 5) studies can assist in the diagnosis of Myasthenia Gravis when characteristic patterns are present. Also, the repetitive nerve stimulation to check for a post-synaptic defect, single fiber EMG, or a muscle biopsy to look for antibodies may also be used to diagnose Myasthenia Gravis. There are cases where all of these tests are negative or equivocal in people whose symptoms and examination still appear to point to a diagnosis of Myasthenia Gravis. The positive clinical findings are then further assessed, and may take precedence over negative test results. Treatment: There is no known cure for Myasthenia Gravis, but there are effective treatments that greatly improve the quality of life and allow patients to lead full lives. Common treatments include medications, plasmapheresis, and thymectomy. Medications are most frequently used in treatment. Anticholinesterase medications (like Mestinon) allow acetylcholine to remain at the neuromuscular junction longer than usual so that more receptor sites can be activated. Corticosteroids (like prednisone) and immunosuppressant medications (like Imuran) may be used to suppress the abnormal action of the immune system that occurs in Myasthenia Gravis. Intravenous immunoglobulins (IVIg) are sometimes used to affect the function or production of the abnormal antibodies also. Atropine can be used for cholinergic crisis (due to excessive anticholinesterase therapy). Thymectomy (surgical removal of the thymus gland) is another treatment used in some patients. The thymus gland is an important part of the immune system, located behind the breastbone. When there is a tumor of the thymus gland (in 10-15% of patients with Myasthenia Gravis), it is always removed because of the risk of malignancy. Thymectomy frequently lessens the severity of the MG weakness after a few months. In some people, the weakness may completely disappear, and remission occurs. The degree to which the thymectomy helps does vary with each patient. Plasmapheresis, or plasma exchange, can also be useful in the treatment of Myasthenia Gravis. This procedure involves removal of the abnormal antibodies from the blood plasma. There may be great muscle strength improvement initially, but that is usually short-lived, because the production of the abnormal antibodies continues. When plasmapheresis is used, repeat plasma 18 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

19 exchanges may be required. Plasma exchange can be very useful prior to surgery, or during severe Myasthenia Gravis weakness stages. The choice of these treatments are highly individualized, based on each patient s history, their degree of weakness, their age, sex, and on their predicted response to a specific type of treatment. Rest is usually also advised. One must monitor respiratory muscle strength including the vital capacity (VC), and the negative inspiratory force (NIF). The VC and NIF can reveal if respiratory muscle strength is declining. Ventilatory support may be indicated, with BiPAP or invasive mechanical ventilation. Modern medicine has improved the outlook for Myasthenia Gravis patients. Current therapies greatly improve the quality of life. Although there is no cure for Myasthenia Gravis, most patients will have significant improvement in their muscle weakness. In some cases, Myasthenia Gravis goes into remission, during which time no treatment is necessary. Spontaneous improvement and even remission sometimes occurs without any specific therapy. Research continues, to find the answers, improve the medications, improve the treatments, and improve the quality of life for those afflicted with Myasthenia Gravis. OTHER NEUROMUSCULAR DISORDERS POLIO Description: P olio (Poliomyelitis) is a very severe viral disease, usually affecting children under 5 years of age. It is highly contagious and inflames the brainstem and spinal cord, sometimes leading to loss of voluntary movement and muscular wasting. It invades the nervous system, and can cause total paralysis in a matter of hours. The virus enters the body through the mouth and multiplies in the intestine. One in every 200 infections leads to irreversible paralysis (usually in the legs). The muscles of ventilation can also be affected, and many of these patients had to use the iron lung to sustain their life. Among those paralyzed, 5% to 10% die when their muscles of respiration become immobilized. Polio is also known as infantile paralysis, as it afflicts such young children. The good news is that, as of 2008, polio cases have decreased by over 99% since 1988 as a result of the global effort to eradicate the disease. As of 2008, only 4 countries in the world remain polio-endemic. These countries are Afghanistan, Pakistan, India, and Nigeria. The polio eradication initiative is focused on these countries at this time. Signs and Symptoms: Initial symptoms are fever, headache, fatigue, vomiting, stiffness in the neck, and pain in the limbs. This can lead to paralysis and respiratory failure. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 19

20 Prevention: There is no cure for polio. Prevention is available and necessary, via the Polio vaccine. Given multiple times, it can protect one for life. Notes on Post Polio Syndrome: There are people who had paralytic polio in the past, who develop post polio syndrome (PPS). Approximately 25 to 50% of the paralytic polio survivors develop PPS, and can be afflicted with the syndrome decades after the original illness. The cause is unknown, and there is no known cure. Symptoms include, low endurance, fatigue, weakness, muscle pain, joint pain, sleep difficulties, muscle twitches, and other symptoms which range from mild to severe. Supportive care, and controlling the symptoms in the best way possible are the main goals, in order to improve the quality of life. MUSCULAR DYSTROPHY M uscular dystrophy refers to an inherited condition in which a person has particularly weak muscle tissue, which can cause his muscles to become easily damaged. Although many medical experts categorize muscular dystrophy as a type of myopathy, it is, in fact, a separate condition. However, because MD is a degenerative muscle condition, many still classify it as a type of myopathy. A myopathy is defined as a disease of the muscle. Myopathic diseases can adversely affect respiratory/ventilatory function. Primary muscle diseases can decrease the ability of the muscles to contract because the normal depolarizing impulse to generate effective muscle contractions is adversely affected. Below is a list of the many types of muscular dystrophies and myopathies. Muscular Dystrophies: Congenital Muscular Dystrophy (CMD) Myotonic Dystrophy (MMD) (Also known as Steinert's Disease) Duchenne s muscular dystrophy (DMD, Also known as Pseudohypertrophic) Becker Muscular Dystrophy (BMD) Emery-Dreifuss Muscular Dystrophy (EDMD) Limb-Girdle Muscular Dystrophy (LGMD) 20 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

21 Facioscapulohumeral Muscular Dystrophy (FSH or FSHD) (Also known as Landouzy- Dejerine) Oculopharyngeal Muscular Dystrophy (OPMD) Distal Muscular Dystrophy (DD) Myopathies: Congenital myopathies Centronucleur myopathy Nemaline rod myopathy Inflammatory myopathies Polymyositis Dermatomyositis Metabolic myopathies Acid maltase deficiencies Mitochondrial myopathies (Kearns-Sayre syndrome) Endocrine myopathies Hyperthyroid and Hypothyroid-related myopathies Steroid-induced myopathies Miscellaneous myopathies Post neuromuscular blockade myopathy Periodic paralysis Rhabdomyolysis Electrolyte disorders including hypokalemia and hypophosphatemia The muscular dystrophies are a group of more than 30 genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles that control movement. Some types of muscular dystrophy occur in infants and children, while others do not appear until middle age or later. The disorders differ in terms of the age of onset, rate of progression, extent of muscle weakness, distribution of muscle weakness, and type of muscular dystrophy inherited. The most common form of muscular dystrophy is Duchenne muscular dystrophy. It affects primarily males, and is caused by the absence of dystrophin, a protein that helps maintain muscle integrity. Most of the boys affected are unable to walk by age 12, and later need ventilatory support to assist breathing. The females in these families have a 50% chance of inheriting and This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 21

22 passing the defective gene to their children. Becker muscular dystrophy is similar to Duchenne, but less severe. In adults, the most common form is myotonic muscular dystrophy. There exists no cure for muscular dystrophy, and there is no specific treatment to stop or reverse any form of muscular dystrophy. Therapies can include physical therapy, respiratory therapy, speech therapy, orthopedic appliances used for support, and corrective orthopedic surgery. Drug therapy includes: immunosuppressants to help delay damage to muscle cells, corticosteroids to slow muscle degeneration, anticonvulsants to control seizures and some muscle activity, and antibiotics to combat respiratory infections. Some individuals may benefit from occupational therapy. Some patients may need a pacemaker for cardiac dysfunction. Ventilatory support is needed for some patients to assist their respiratory muscle weakness. MULTIPLE SCLEROSIS M ultiple sclerosis (MS) is a serious progressive disease of the central nervous system, occurring mainly in young adults and thought to be caused by a malfunction of the immune system. MS is chronic and unpredictable. It leads to the loss of myelin in the brain or spinal cord and causes muscle weakness, poor eyesight, slow speech, and some inability to move. There are several forms of MS, but all forms affect nerve function, and result in problems ranging from mild numbness and difficulty walking, to paralysis and blindness. Multiple sclerosis can occur at almost any age, but usually afflicts people between the age of 20 and 40. Approximately 2.5 million people in the world have MS, and approximately 400,000 people in the USA are afflicted with the disease. MS can produce many different respiratory complications due to the multiple adverse affects of the central nervous system. Respiratory complications usually occur in advanced stages of MS, and also complicate acute relapses early in the disease. The patients can display severe respiratory insufficiency, hypoxemia, and hypercapnea. Respiratory insufficiency can be treated with positive pressure ventilation. Medications can help ease the symptoms of MS and possibly slow the disease. Acupuncture and other alternative treatments can help relieve pain. Plasmapheresis is also utilized, and deep brain stimulation to help control tremors. CONCLUSION T here are many neuromuscular diseases that can impair multiple bodily functions, including impairment of the pulmonary system. Many neuromuscular diseases have no cure, so the treatment is aimed at supportive care, improving systems, improving mobility, treating complications, supportive care, lengthening life expectancy, and improving the quality of life. 22 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

23 Research continues in the multitude of neuromuscular diseases. Neurological scientists, immunologists, virologists, pharmacologists, and physicians are all working collaboratively to learn how to prevent these disorders and to make better therapies available when they strike. New drugs and therapies are still needed to continue in the effort of finding the answers and curing the diseases. Research plays an important role, as new medications and therapies are continually being developed. Modern medicine has aided in reducing the symptoms, decreasing the duration of many illnesses, lengthening the life expectancy, improving the prognosis, and improving the overall quality of life for patients with neuromuscular disorders. SUGGESTED READING AND REFERENCES: 1. Wilkins, Robert L., Scanlan, Craig L., Stoller, James K.: Egan's Fundamentals of Respiratory Care. 8 th edition Elsevier Science. 2. ALS Association. Available online: Accessed November, National Institute of Neurological Disorders and Stroke. Available online: Accessed November, Guillain-Barré Syndrome. Available online: Accessed November, Myasthenia Gravis: Available online: Accessed November, used: 6. Polio: Available online: Accessed November, Muscular Dystrophy: Muscular Dystrophy Association. Available online: Accessed November, Multiple Sclerosis: Available online: Accessed November, Gold, Warren M., Nadel, Jay A.: Atlas of Procedures in Respiratory Medicine WB Saunders Company. 10. Wyka, Kenneth A., Mathews, Paul, Clark, William F., et al.: Foundations of Respiratory Care Delmar Learning. 11. Oakes, Dana F. Clinical Practitioners Pocket Guide to Respiratory Care Health Educator Publications, Inc. This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 23

24 12. Czervinske, Barnhart, Sherry. Perinatal and Pediatric Respiratory Care WB Saunders Company. 13. Lewis, Sharon, Dirksen, Shannon Ruff, Heitkemper, Margaret. Medical Surgical Nursing Elsevier Science. 14. Damico, Christine M., RN, MSN, CPNP, et al.: Nursing 2004 Drug Handbook. Springhouse Corporation. 15. PDR Staff Physicians: Physicians' Desk Reference. 58 th edition Medical Economics Company. 16. Cairo, J.M., Pill beam, Susan Mosby s Respiratory Care Equipment. Elsevier Health Science. 24 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

25 POST TEST DIRECTIONS: Use the FasTrax answer sheet enclosed with your order to respond to all the test questions that follow. Leave the remaining answer circles on the FasTrax answer sheet blank. Be sure to fill in circles completely using blue or black ink. The FasTrax grading system will not read pencil. If you make an error, you may use correction fluid (such as White Out) to correct it. FasTrax answer sheets are preprinted with your name and address and the course title. If you are completing more than one course, be sure to record your answers on the correct corresponding answer sheet. RETURN TO: RCECS, P.O. Box 1930, Brockton, MA or FAX TO: (508) The pulmonary problems associated with neuromuscular disease typically includes: a. hypoventilation b. atelectasis c. hypoxemia d. all of the above 2. Which of the following agents can affect the neuromuscular junction? a. curare and ibuprofen b. botulism toxin and acetaminophen c. anticholinesterase drugs and succinylcholine d. anticholinesterase drugs only 3. Which of the following are NOT TRUE of acetylcholine (ACh)? a. acetylcholine (ACh) is formed from a reaction of Acetyl-CoA and choline b. acetylcholine receptor antibody testing is not recommended for Myasthenia Gravis patients c. acetylcholine is a neurotransmitter d. acetylcholine sends electrical impulses across synapses between nerve cells from motor neurons to muscle cells, causing the muscle cells to contract. 4. The pulmonary complications of neuromuscular disorders can be observed and managed with all of the following except: a. Lumbar puncture b. BIPAP c. Invasive mechanical ventilation d. Monitoring of the VC and NIF This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 25

26 5. Which of the following neuromuscular disorders has a cure? a. ALS b. Guillain-Barré c. Myasthenia Gravis d. None of the above 6. Which of the following are true of Amyotrophic Lateral Sclerosis (ALS)? I. ALS is a highly contagious disease. II. ALS is also called Lou Gehrig s Disease. III. ALS is characterized by progressive degeneration of the brain and spinal cord motor neurons. IV. In ALS, there is progressive atrophy of the hands, forearms, and legs. V. In ALS, the progressive muscle weakness can impair the muscles of ventilation. a. I, III, V b. II, III, IV, V c. I, II, III, IV d. I, II, III, IV, V 7. Some signs and symptoms of ALS include: Muscle weakness, hypoventilation, ineffective cough, atelectasis, hypoxemia, hypercapnia, and respiratory insufficiency. a. true b. false 8. Tests used to diagnose ALS include: a. EMG b. NCV c. Neurological examination d. all of the above 9. Which of the following treatments can be used for ALS patients? a. BIPAP, oxygen, and Riluzole. b. BIPAP, oxygen, and vaccination for ALS. c. Mestinon is the only treatment for ALS. d. Invasive mechanical ventilation is the only therapy for ALS. 26 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

27 10. Guillain-Barré syndrome is also known as Inflammatory Demyelinating Polyneuropathy. a. true b. false 11. Which of the following are true regarding Guillain-Barré syndrome? a. The patient is most often afflicted with a descending muscle paralysis. b. Clostridium perfringens is the main causative bacteria in Guillain-Barré syndrome. c. Symptoms usually begin within 1 to 6 weeks after an infection, illness, or surgery. d. All of the above are true. 12. There now exists a cure for Guillain-Barré syndrome. a. true b. false 13. Which of the following are true of Myasthenia Gravis? a. Weakness usually occurs in an ascending manner, from the feet upward. b. Weakness usually occurs in a descending manner, from the face downward. c. The Myasthenia Gravis vaccine is the best form of prevention for this disease. d. Myasthenia Gravis is not linked to autoimmune disease. 14. Some common signs and symptoms of Myasthenia Gravis include: a. Weakness and fatigue, especially with exertion.. b. Facial and ocular muscle weakness, with droopy eyelids. c. Impaired swallowing and slurred speech. d. All of the above. 15. The tensilon test is a diagnostic tool for Myasthenia Gravis. a. True b. False 16. Treatment options for Myasthenia Gravis include: a. Plasmapheresis b. Thymectomy c. Anticholinesterase medications d. All of the above This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 27

28 17. All of the following are true of Polio, except: a. Approximately 25 to 50% of the paralytic polio survivors develop post polio syndrome. b. Polio has been completely eradicated from all countries. c. People who suffered paralytic polio in the past can be afflicted with post polio syndrome decades after the original illness. d. Polio (Poliomyelitis) is an infectious viral disease. 18. There are many types of muscular dystrophies including: a. Congenital b. Myotonic c. Duchenne s d. All of the above 19. What is a myopathy? a. A disease of the muscle. b. A disease of the brain. c. A disease of the spinal cord. d. None of the above. 20. Muscular dystrophy is a genetic disease. a. true b. false 28 This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law.

29 COURSE EVALUATION RC Educational Consulting Services, Inc. wishes to provide our customers with the highest quality continuing education materials possible. Your honest feedback will help us to continually improve our courses and meet state regulations. Responses to the following evaluation questions should be recorded in the far right hand column of the FasTrax answer sheet, in the section marked Evaluation. Mark A for Yes and B for No. Thank you YES (A) NO (B) 1. Were the objectives of the course met? 2. Was the material presented in a clear and understandable manner? 3. Was the material well-organized? 4. Was the content presented without bias of any commercial product or drug? 5. Was the material relevant to your job? 6. Did you learn something new? 7. Was the material interesting? 8. Were the illustrations, if any, helpful? 9. Would you recommend this course to a friend? This material is copyrighted by RC Educational Consulting Services, Inc. Unauthorized duplication is prohibited by law. 29

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