Myopathy
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Myopathy
The myopathies are a family of neurological diseases in which the primary symptom
is muscle weakness due to dysfunction of muscle fiber. Other symptoms of myopathy
can include include muscle cramps, stiffness, and spasm. Myopathies can be
inherited (such as the muscular dystrophies) or acquired (such as common muscle
cramps). Myopathies are grouped as follows:
- congenital myopathies: characterized by developmental delays in motor skills; skeletal and facial abnormalities are occasionally evident at birth
- muscular dystrophies: characterized by progressive weakness in voluntary muscles; sometimes evident at birth
- mitochondrial myopathies: caused by genetic abnormalities in mitochondria, cellular structures that control energy; include Kearns-Sayre syndrome, MELAS and MERRF
- glycogen storage diseases of muscle: caused by mutations in genes controlling enzymes that metabolize glycogen and glucose (blood sugar); include Pompe's, Andersen's and Cori's diseases
myoglobinurias: caused by disorders in the metabolism of a fuel (myoglobin) necessary for muscle work; include McArdle, Tarui, and DiMauro diseases
- dermatomyositis: an inflammatory myopathy of skin and muscle
- myositis ossificans: characterized by bone growing in muscle tissue
-
familial periodic paralysis: characterized by episodes of weakness in the arms
and legs
polymyositis, inclusion body myositis, and related myopathies: inflammatory
myopathies of skeletal muscle neuromyotonia: characterized by alternating episodes of twitching and stiffness;
and stiff-man syndrome, characterized by episodes of rigidity and reflex spasms common muscle cramps and stiffness, and tetany: characterized by prolonged
spasms of the arms and legs
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Treatments for the myopathies depend on the disease or condition and specific
causes. Supportive and symptomatic treatment may be the only treatment available
or necessary for some disorders. Treatment for other disorders may include
drug therapy, such as immunosuppressives, physical therapy, bracing to support
weakened muscles, and surgery.
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The prognosis for individuals with a myopathy varies. Some individuals have
a normal life span and little or no disability. For others, however, the
disorder may be progressive, severely disabling, life-threatening, or fatal.
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National Institute of
Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Muscular Dystrophy Association
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Neuropathy
Multifocal motor neuropathy is a progressive muscle disorder characterized
by muscle weakness in the hands, with differences from one side of the body
to the other in the specific muscles involved. It affects men much more than
women. Symptoms also include muscle wasting, cramping, and involuntary contractions
or twitching of the leg muscles. The disorder is sometimes mistaken for amyotrophic
laterial sclerosis (ALS, or Lou Gehrig's disease) but unlike ALS, it is treatable.
An early and accurate diagnosis allows patients to recover quickly.
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Treatment for multifocal motor neuropathy varies. Some individuals experience
only mild, modest symptoms and require no treatment. For others, treatment
generally consists of intravenous immunoglobulin (IVIg) or immunosuppressive
therapy with cyclophosphamide.
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Improvement in muscle strength usually begins within 3 to 6 weeks after
treatment is started. Most patients who receive treatment early experience
little, if any, disability. However, there is evidence of slow progression
over many years.
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American Chronic Pain
Association (ACPA)
National Chronic Pain
Outreach Association (NCPOA)
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