Muscular Dystrophy
The terms 'muscle disease', 'muscular dystrophy', 'neuromuscular conditions' and 'neuromuscular disorders' all describe a large group of conditions which affect either the muscles, such as those in the arms and legs or heart and lungs, or the nerves which control the muscles. Different conditions affect different muscles.
Most conditions are progressive, causing the muscles to gradually weaken over time. People's mobility is affected and most conditions lead to some sort of disability. The severity of conditions and how they affect individuals varies greatly from person to person.
Muscle disease affects babies, children and adults, both males and females and all ethnic groups. Conditions are often inherited but can also occur out of the blue where there is no family history
There are many different types of muscular dystrophy. They include:
• Becker muscular dystrophy
• Duchenne muscular dystrophy
• Emery-Dreifuss muscular dystrophy
• Facioscapulohumeral muscular dystrophy
• Limb-girdle muscular dystrophy
• Myotonia congenita
• Myotonic dystrophy
Symptoms
Symptoms vary with the different types of muscular dystrophy.
All of the muscles may be affected. Or, only specific groups of muscles may be affected, such as those around the pelvis, shoulder, or face. Muscular dystrophy can affect adults, but the more severe forms tend to occur in early childhood.
Symptoms include:
• Mental retardation (only present in some types of the condition)
• Muscle weakness that slowly gets worse
• Delayed development of muscle motor skills
• Difficulty using one or more muscle groups
• Drooling
• Eyelid drooping (ptosis)
• Frequent falls
• Loss of strength in a muscle or group of muscles as an adult
• Loss in muscle size
• Problems walking (delayed walking)
Signs and tests
A physical examination and your medical history will help the doctor determine the type of muscular dystrophy. Specific muscle groups are affected by different types of muscular dystrophy.
The doctor's exam may show:
• Abnormally curved spine (scoliosis)
• Joint contractures
• Low muscle tone (hypotonia)
Some types of muscular dystrophy involve the heart muscle, causing cardiomyopathy or disturbed heart rhythm (arrhythmias).
Often, there is a loss of muscle mass (wasting), which may be hard to see because some types of muscular dystrophy cause a build-up of fat and connective tissue that makes the muscle appear larger. This is called pseudohypertrophy.
A muscle biopsy may be used to confirm the diagnosis. In some cases, a DNA blood test may be all that is needed.
Other tests may include:
• Heart testing - electrocardiography (ECG)
• Nerve testing - electromyography (EMG)
• Blood testing - including CPK level
• Genetic testing for some forms of muscular dystrophy
This disease may also alter the results of the following tests:
• Aldolase
• AST
• Creatinine
• LDH
• Myoglobin - urine and blood
Treatment
There are no known cures for the various muscular dystrophies. The goal of treatment is to control symptoms.
Physical therapy may help patients maintain muscle strength and function. Orthopedic appliances such as braces and wheelchairs can improve mobility and self-care abilities. In some cases, surgery on the spine or legs may help improve function.
Corticosteroids taken by mouth are sometimes prescribed to children to keep them walking for as along as possible.
The person should be as active as possible. Complete inactivity (such as bedrest) can make the disease worse.
Support Groups
You can ease the stress of illness by joining support groups where members share common experiences and problems.
Expectations (prognosis)
The severity of disability depends on the type of muscular dystrophy. All types of muscular dystrophy slowly get worse, but how fast this happens varies widely.
Some types of muscular dystrophy, such as Duchenne muscular dystrophy, are deadly. Other types cause little disability and people with them have a normal lifespan.
Complications
• Cardiomyopathy
• Decreased ability to care for self
• Decreased mobility
• Lung failure
• Tightening of muscles around the joints (contractures)
• Mental impairment (varies)
• Scoliosis
Prevention
Genetic counseling is advised when there is a family history of muscular dystrophy. Women may have no symptoms but still carry the gene for the disorder. Duchenne muscular dystrophy can be detected with about 95% accuracy by genetic studies performed during pregnancy.
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