RIGHT INFORMATION
BETTER TREATMENT
ABOUT YOUR CONDITION
Muscular dystrophy refers to a group of more than 30 inherited (genetic) diseases that cause muscle weakness. These conditions are a type of muscle disease which affect the voluntary muscles of the skeletal muscles. Over time, muscles shrink and become weaker, affecting the ability to walk and perform daily activities like brushing teeth. The disease also can affect heart and lungs. Some forms of muscular dystrophy are apparent at birth or develop during childhood. Others develop later during adulthood. It is a rare condition.
There are more than 30 different types of muscular dystrophy. Some of the more common forms include:
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Duchenne muscular dystrophy (DMD): This condition tends to affect boys between the ages of 2 to 5, but girls can get it, too. You may notice that your toddler has a hard time running, walking or jumping. As the disease progresses, it can affect a child’s heart and lungs. DMD is the most common form of muscular dystrophy. It affects approximately six out of 100,000 children in North America and Europe.
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Becker muscular dystrophy (BMD): BMD is the second most common muscular dystrophy. Symptoms of BMD can appear anytime between age 5 and 60, but typically come on during the teen years. Males are more likely to get BMD. The disease affects the hip, thigh and shoulder muscles, and eventually the heart. Approximately one out of 18,000 to 30,000 U.S. boys develop BMD.
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Facioscapulohumeral muscular dystrophy (FSHD): FSHD is the third most common muscular dystrophy. The disease affects muscles in the face, shoulder blades and upper arms. Symptoms tend to appear before age 20. About four out of 100,000 people in the U.S. have this form.
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Congenital muscular dystrophies (CMD): Congenital conditions like CMD are present at birth. An infant may have weak muscles, a curved spine and joints that are too stiff or loose. Children with CMD may have learning disabilities, seizures and vision problems.
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Emery-Dreiffus muscular dystrophy (EDMD): This condition tends to affect children. Symptoms, such as weak shoulders, upper arms and calf muscles, appear by age 10. EDMD also affects the heart.
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Limb-girdle muscular dystrophy (LGMD): This disease affects the muscles closest to the body including the shoulders and hips. It affects people of all ages. Approximately two out of 100,000 people in the U.S. have LGMD.
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Myotonic dystrophy: People with myotonia have trouble relaxing their muscles. For instance, you might find it difficult to relax your hand after tightly gripping any object. The disease also affects the heart and lungs. This condition tends to affect adults of European descent and occurs in approximately 10 out of 100,000 people.
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Oculopharyngeal muscular dystrophy (OPMD): This rare form of muscular dystrophy weakens muscles in the eyelids and throat. Symptoms, such as droopy eyelids and difficulty swallowing often appear between the 40s and 60s. About one in 100,000 people have OPMD.
Metabolic myopathies are genetic defects that interfere with the processes in muscles that generate energy. When these defects interfere with muscle function and block energy production, the cells in the muscles cannot work properly. Then the muscles that help the body’s movement are unable to communicate (“talk”) between bones and joints. These myopathies can cause progressive muscle weakness, fatigue, episodes of pain and cramps after exercise, and/or extensive breakdown of muscle tissue. Metabolic refers to chemical reactions that provide energy, nutrients and substances necessary for health and growth. Some people with a metabolic myopathy (muscle disease) develop weakness; others tire easily with exercise or physical activity, suffer muscle pain after physical effort, and/or experience severely swollen and tender muscles. These symptoms occur when muscle cells don’t get enough energy. Without enough energy, the muscle lacks enough fuel to work properly.
Most metabolic myopathies are genetic and tend to occur within families. They can appear at any age in those who inherit the disease. Either a parent or another relative may have been symptomatic. However, metabolic myopathies can develop in a person with no family history of the condition. Some myopathies can cause rhabdomyolysis. In which, muscles break down, leaving them very weak, sore, swollen and tender. As muscles break down, portions of muscle fiber enter the bloodstream, which can lead to kidney failure.
The inflammatory myopathies are a group of diseases, with no known cause, that involve chronic muscle inflammation accompanied by muscle weakness. The majority of these disorders are considered to be autoimmune disorders, in which the body’s immune response system that normally defends against infection and disease attacks its own muscle fibers, blood vessels, connective tissue, organs, or joints. These rare disorders may affect both adults and children.
The four main types of chronic, or long-term, inflammatory myopathies are:
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polymyositis, which affects skeletal muscles (involved with making movement)
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dermatomyositis, which includes a skin rash and progressive muscle weakness
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inclusion body myositis, which is characterized by progressive muscle weakness and shrinkage
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necrotizing autoimmune myopathy, with weakness in the upper and lower body, difficulty rising from low chairs or climbing stairs, fatigue, and muscle pain.
General symptoms of chronic inflammatory myopathy include progressive muscle weakness that starts in the proximal muscles--those muscles closest to the trunk of the body. Other symptoms include fatigue after walking or standing, tripping or falling, and difficulty swallowing or breathing. Polymyositis and dermatomyositis are more common in women than in men. Inclusion body myositis is most common after age 50. Dermatomyositis is more common in children.
All forms of myasthenia are due to problems in the communication between nerve cells and muscles. Most involve the activities of neurotransmitters. Neurotransmitters are chemicals that allow neurons to relay information from one cell to the next. For neurotransmitters to be effective, the nerve cell must release the neurotransmitter properly, and the muscle cell must be able to detect the neurotransmitter and respond to its signal properly. Congenital myasthenia is caused by genetic defects. There are several different subtypes of congenital myasthenia, each the result of a specific genetic mutation. Since all types of myasthenia are due to the inability of nerves to trigger muscle activity, they all involve weakness, although there is some variability in the specific muscles affected.
Symptoms of congenital myasthenia usually appear in the first few years of childhood, but may not be noticeable until much later, occasionally remaining unrecognized until adulthood. If the symptoms begin in infancy, they usually appear as "floppiness" and a failure to meet developmental milestones, such as rolling over or sitting up. Some infants may also have episodes of choking or pauses in breathing. If the symptoms begin in toddlers or preschool children, they appear as weakness during physical activities or an inability to perform age-appropriate actions, such as running or climbing. In addition, if eye muscles are involved, children may have droopy eyelids, "lazy eye," or double vision. If mouth or throat muscles are involved, children may have difficulty speaking or swallowing. An important characteristic of myasthenia is that the weakness worsens during continuous activity, with strength returning, at least partially, after resting.
Congenital myasthenia is an inherited (genetic) disorder. All but one known subtype are recessive disorders, which means that a child will have to have two copies of the abnormal gene (one from each parent) in order to develop the disease. To diagnose congenital myasthenia, a neurologist will test various muscles to determine if they grow weaker with repeated activity. The doctor will also test the electrical activity of nerves and muscles using electromyography (EMG) and nerve conduction tests (NCS). Blood tests are often used to determine if antibodies could be causing the symptoms. Genetic tests may be ordered.
Myasthenia gravis is a chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal muscles of the body, which are responsible for breathing and moving parts of the body, including the arms and legs. In myasthenia gravis, the immune system--which normally protects the body from foreign organisms--mistakenly attacks itself. Symptoms vary in type and intensity, and may include:
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muscle weakness in the arms, hands, fingers, legs and neck
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weakness of the eye muscles
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drooping eyelid
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difficulty swallowing
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shortness of breath
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impaired speaking
Myasthenia gravis is caused by an error in the transmission of nerve impulses to muscles. Antibodies (immune proteins produced by the body's immune system) block the normal activity of the neurotransmitter acetylcholine, which prevents muscles from contracting. The thymus gland also may give incorrect instructions to immune cells and cause the immune system to attack its own cells and tissues.
Hereditary neuropathies are a group of inherited disorders affecting the peripheral nervous system. The hereditary neuropathies are divided into four major subcategories: hereditary motor and sensory neuropathy, hereditary sensory neuropathy, hereditary motor neuropathy, and hereditary sensory and autonomic neuropathy. The most common type is Charcot-Marie-Tooth disease, one of the hereditary motor and sensory neuropathies. Symptoms of the hereditary neuropathies vary according to the type and may include sensory symptoms such as numbness, tingling, and pain in the feet and hands; or motor symptoms such as weakness and loss of muscle bulk, particularly in the lower leg and feet muscles. Certain types of hereditary neuropathies can affect the autonomic nerves, resulting in impaired sweating, postural hypotension, or insensitivity to pain. Some people may have foot deformities such as high arches and hammer toes, thin calf muscles (having the appearance of an inverted champagne glass) or scoliosis (curvature of the spine). The symptoms of hereditary neuropathies may be apparent at birth or appear in middle or late life. They can vary among different family members, with some family members being more severely affected than others. The hereditary neuropathies can be diagnosed by blood tests for genetic testing, nerve conduction studies, and nerve biopsies.
The inflammatory myopathies are a group of diseases that involve chronic (long-standing) muscle inflammation, muscle weakness, and, in some cases, muscle pain. Myopathy is a general medical term used to describe a number of conditions affecting the muscles. All myopathies cause muscle weakness.
The four main types of chronic, or long-term, inflammatory myopathies are:
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polymyositis
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dermatomyositis
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inclusion body myositis
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necrotizing autoimmune myopathy
Although the cause of many inflammatory myopathies is unknown, the majority are considered to be autoimmune disorders, in which the body’s immune response system that normally defends against infection and disease attacks its own muscle fibers, blood vessels, connective tissue, organs, or joints. The inflammatory myopathies are rare and can affect both adults and children. Dermatomyositis is the most common chronic form in children. Polymyositis and dermatomyositis are more common in females while inclusion body myositis affects more men. Inclusion body myositis usually affects individuals over age 50.
Diabetic neuropathy is a peripheral nerve disorder caused by diabetes or poor blood sugar control. The most common types of diabetic neuropathy result in problems with sensation in the feet. It can develop slowly after many years of diabetes or may occur early in the disease. The symptoms are numbness, pain, or tingling in the feet or lower legs. The pain can be intense and require treatment to relieve the discomfort. The loss of sensation in the feet may also increase the possibility that foot injuries will go unnoticed and develop into ulcers or lesions that become infected. In some cases, diabetic neuropathy can be associated with difficulty walking and some weakness in the foot muscles. There are other types of diabetic-related neuropathies that affect specific parts of the body. For example, diabetic amyotrophy causes pain, weakness and wasting of the thigh muscles, or cranial nerve infarcts that may result in double vision, a drooping eyelid, or dizziness. Diabetes can also affect the autonomic nerves that control blood pressure, the digestive tract, bladder function, and sexual organs. Problems with the autonomic nerves may cause light-headedness, indigestion, diarrhea or constipation, difficulty with bladder control, and impotence.
Radiculopathy refers to damage to multiple nerve roots sufficient to produce neurologic symptoms and signs such as pain, weakness, and sensory loss. In radiculopathy, the problem occurs at or near the site of the origin of the nerve root as it exits from the spinal cord, but the pain and accompanying symptoms usually radiate to the part of the body that is supplied by that specific nerve. For example, a nerve root impingement in the cervical spine may result in pain and weakness in the forearm. Similarly, an impingement in the lumbar region can be manifested with symptoms in the foot. Thoracic radiculopathy causes pain from the middle back that travels around to the chest. There are certain diseases associated with Radiculopathy such as Lumber canal stenosis which is one of the most common causes of the radiculopathy but it can be caused by other diseases such as tuberculosis, Malignancy and these diseases needs through investigation. Radiculopathy's diagnosis commonly made by physicians in primary care specialties, Chiropractic, orthopedics, physiatry, and neurology. The diagnosis may be suggested by symptoms of pain, numbness, and weakness in a pattern consistent with the distribution of a particular nerve root. Neck pain or back pain may also be present. Two additional diagnostic tests that may be of use are MRI magnetic resonance imaging and electrodiagnostic testing, consisting of NCS (Nerve conduction study) and EMG (Electromyography). Electrodiagnostic testing plays key role in the diagnosis of acute and chronic radiculopathies of both cervical and lumbosacral radiculopathies.
Amyotrophic lateral sclerosis or ALS, is a progressive nervous system disease that affects nerve cells in the brain and spinal cord, causing loss of muscle control. ALS is often called Lou Gehrig's disease, after the baseball player who was diagnosed with it. Doctors usually don't know why ALS occurs. Some cases are inherited. ALS often begins with muscle twitching and weakness in a limb, or slurred speech. Eventually, ALS affects control of the muscles needed to move, speak, eat and breathe. There is no cure for this fatal disease.
Signs and symptoms of ALS vary greatly from person to person, depending on which neurons are affected. It generally begins with muscle weakness that spreads and gets worse over time. Signs and symptoms might include:
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Difficulty walking or doing normal daily activities
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Tripping and falling
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Weakness in your legs, feet or ankles
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Hand weakness or clumsiness
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Slurred speech or trouble swallowing
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Muscle cramps and twitching in your arms, shoulders and tongue
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Inappropriate crying, laughing or yawning
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Cognitive and behavioral changes
ALS often starts in the hands, feet or limbs, and then spreads to other parts of your body. As the disease advances and nerve cells are destroyed, your muscles get weaker. This eventually affects chewing, swallowing, speaking and breathing. There's generally no pain in the early stages of ALS, and pain is uncommon in the later stages.
Spinal muscular atrophy (SMA) is a group of inherited disorders characterized by a loss of certain nerve cells in the spinal cord called motor neurons or anterior horn cells. Motor neurons receive the nerve impulses transmitted from the brain to the spinal cord (brainstem) and, in turn, transmit the impulses to the muscle via the peripheral nerves. The loss of motor neurons leads to progressive muscle weakness and muscle wasting (atrophy) in muscles closest to the trunk of the body (proximal muscles) such as the shoulders, hips and back. These muscles are necessary for crawling, walking, sitting up and head control. The more severe types of SMA can affect muscles involved in feeding, swallowing and breathing.
SMA is divided into subtypes based on age of onset and maximum function achieved. SMA types 0, 1, 2, 3 and 4 are inherited as autosomal recessive genetic disorders and are associated with abnormalities (mutations) in the SMN1 and SMA2 genes which are located on chromosome 5.
SMA type 0 is the most severe form of the disease and is characterized by decreased fetal movement, joint abnormalities, difficulty swallowing and respiratory failure.
SMA type 1 is the most common type of SMA and is also a severe form of the disease. Infants with SMA type 1 experience severe weakness before 6 months of age and never sit independently. Muscle weakness, lack of motor development and poor muscle tone are the major clinical manifestations of SMA type I. Infants with the gravest prognosis have problems sucking or swallowing. Some show abdominal breathing in the first few months of life. Muscle weakness occurs on both sides of the body and the ocular muscles are not affected. A twitching of the tongue is often seen. Intelligence is normal. Most affected children die before two years of age but survival may be dependent on the degree of respiratory function. For more information about SMA type 1, chose “Werdnig Hoffman” disease as your search term in the Rare Disease Database.
The onset of weakness in SMA type 2 patients is usually between 6 and 12 months. Affected children are able to sit independently early in development but are unable to walk even 10 feet independently. A trembling (tremor) of the fingers is almost always seen in SMA type 2. Approximately 70% of those affected do not have deep tendon reflexes. Those affected with
SMA type 2 are usually not able to sit independently by the mid-teens or later.
Patients with SMA type 3 (Kugelberg-Welander syndrome) learn to walk but fall frequently and have trouble walking up and down stairs at 2-3 years of age. The legs are more severely affected than the arms. The long-term prognosis depends on the degree of motor function attained as a child.
The onset of muscle weakness for those with SMA type 4 is after age 10 years; these patients usually are ambulatory until age 60 years.
Stiff-person syndrome (SPS) is a rare neurological disorder with features of an autoimmune disease. SPS is characterized by fluctuating muscle rigidity in the trunk and limbs and a heightened sensitivity to stimuli such as noise, touch, and emotional distress, which can set off muscle spasms. Abnormal postures, often hunched over and stiffened, are characteristic of the disorder. People with SPS can be too disabled to walk or move, or they are afraid to leave the house because street noises, such as the sound of a horn, can trigger spasms and falls. SPS affects twice as many women as men. It is frequently associated with other autoimmune diseases such as diabetes, thyroiditis, vitiligo, and pernicious anemia. Scientists don’t yet understand what causes SPS, but research indicates that it is the result of an autoimmune response. The disorder is often misdiagnosed as Parkinson’s disease, multiple sclerosis, fibromyalgia, psychosomatic illness, or anxiety and phobia. A definitive diagnosis can be made with a blood test that measures the level of glutamic acid decarboxylase (GAD) antibodies in the blood. People with SPS have elevated levels of GAD, an antibody that works against an enzyme involved in the synthesis of an important neurotransmitter in the brain.