Myopathy
Classification and external resources
ICD-10	G71.-G72., M60.-M63.
ICD-9	359.4-359.9, 728-728
DiseasesDB	8723
eMedicine	emerg/328
MeSH	D009135

In medicine, a myopathy is a muscular disease^[1] in which the muscle fibers do not function for any one of many reasons, resulting in muscular weakness. "Myopathy" simply means muscle disease (myo- Greek μυσ "muscle" + -pathy Greek "suffering"). This meaning implies that the primary defect is within the muscle, as opposed to the nerves ("neuropathies" or "neurogenic" disorders) or elsewhere (e.g., the brain etc.). Muscle cramps, stiffness, and spasm can also be associated with myopathy.

Muscular disease can be classified as neuromuscular or musculoskeletal in nature.

Some conditions, such as myositis, can be considered both neuromuscular and musculoskeletal.

Contents 1 Classes 1.1 Congenital 1.2 Acquired 2 Symptoms 3 Treatments 4 References

[edit] Classes

Because myopathy is such a general term, there are several classes of myopathy.... (ICD-10 codes are provided where available.)

[edit] Congenital

• (G71.0) Dystrophies (or muscular dystrophies) are a subgroup of myopathies characterized by muscle degeneration and regeneration. Clinically, muscular dystrophies are typically progressive, because the muscles' ability to regenerate is eventually lost, leading to progressive weakness, often leading to use of a wheelchair, and eventually death, usually related to respiratory weakness.
• (G71.1) Myotonia
  • Neuromyotonia
• (G71.2) The congenital myopathies do not show evidence for either a progressive dystrophic process (i.e., muscle death) or inflammation, but instead characteristic microscopic changes are seen in association with reduced contractile ability of the muscles. Among others, different congenital myopathies include:
  • (G71.2) nemaline myopathy (characterized by presence of "nemaline rods" in the muscle),
  • (G71.2) multi/minicore myopathy (characterized by multiple small "cores" or areas of disruption in the muscle fibers),
  • (G71.2) centronuclear myopathy (or myotubular myopathy) (in which the nuclei are abnormally found in the center of the muscle fibers) is a rare muscle wasting disorder.
• (G71.3) Mitochondrial myopathies are due to defects in mitochondria, which provide a critical source of energy for muscle.
• (G72.3) Familial periodic paralysis
• (G72.4) Inflammatory myopathies are caused by problems with the immune system attacking components of the muscle, leading to signs of inflammation in the muscle.
• (G73.6) Metabolic myopathies result from defects in biochemical metabolism that primarily affect muscle
  • (G73.6/E74.0) Glycogen storage diseases may affect muscle
  • (G73.6/E75) Lipid storage disorder

[edit] Acquired

• (M33.0-M33.1)
  • Dermatomyositisis the same as polymyositis, but also shows skin changes - a violaceous periorbital rash, facial erythema, blue or red patches on the knuckles, ragged nail folds and dilated nail capilliaries. (M33.2)
  • polymyositis which has tender, weak muscles, a mild normocytic anaemia, raised creatinine kinase and inflammatory markers and shows short polyphasic action potentials on EMG. it is treated by immunosuppressants like corticosteroids or azathioprine.
  • inclusion body myositis, and related myopathies
• (M61) Myositis ossificans
• (M62.89) Rhabdomyolysis and (R82.1) myoglobinurias

[edit] Symptoms

• Common muscle (R25.2) cramps and (M25.6) stiffness, and (R29.0) tetany

[edit] Treatments

Because different types of myopathies are caused by many different pathways, there is no single treatment for myopathy. Treatments range from treatment of the symptoms to very specific cause-targeting treatments. Drug therapy, physical therapy, bracing for support, surgery, and even acupuncture are current treatments for a variety of myopathies.

[edit] References

v • d • e Diseases of myoneural junction and muscle / neuromuscular disease (G70-G73, 358-359) Neuromuscular- junction disease autoimmune (Myasthenia gravis, Lambert-Eaton myasthenic syndrome) Myopathy/ congenital myopathy Muscular dystrophy (DAPC) AD Limb-girdle muscular dystrophy 1 · Oculopharyngeal · Facioscapulohumeral · Myotonic · Distal (most) AR Limb-girdle muscular dystrophy 2 · Congenital (Fukuyama, Ullrich) XR dystrophin (Becker's, Duchenne) · Emerin Emery-Dreifuss Other structural collagen disease (Bethlem myopathy) · PTP disease (X-linked MTM) · adaptor protein disease (BIN1-linked centronuclear myopathy) · cytoskeleton disease (Nemaline myopathy, Zaspopathy) Channelopathy Myotonia Myotonia congenita · Thomsen disease · Neuromyotonia/Isaacs syndrome · Paramyotonia congenita Periodic paralysis Hypokalemic · Hyperkalemic Other Central core disease Mitochondrial myopathy MELAS · MERRF · KSS · PEO Other Inflammatory myopathy muscle, DF+DRCT navs: anat/hist/physio, acquired myopathy/congenital myopathy/neoplasia, symptoms+signs/eponymous, proc

v • d • e Systemic CT disorders (M32-M36, 710) Mixed connective tissue disease Systemic lupus erythematosus: Drug-induced SLE · Libman-Sacks endocarditis Dermatopolymyositis/Inflammatory myopathy/Myositis: Dermatomyositis (Juvenile dermatomyositis) · Polymyositis · Inclusion body myositis Scleroderma: Systemic scleroderma (Progressive systemic sclerosis, CREST syndrome) Other hypersensitivity/autoimmune Sjögren's syndrome Other Behçet's disease · Polymyalgia rheumatica · Eosinophilic fasciitis · Eosinophilia-myalgia syndrome muscle, DF+DRCT navs: anat/hist/physio, acquired myopathy/congenital myopathy/neoplasia, symptoms+signs/eponymous, proc

v • d • e Myopathy (M60-M63, 728) Pain Myalgia (Fibromyalgia) Inflammation Myositis (Pyomyositis) Lytic Muscle weakness · Rhabdomyolysis Other Myositis ossificans (Fibrodysplasia ossificans progressiva) · Compartment syndrome · Diastasis of muscle (Diastasis recti) muscle, DF+DRCT navs: anat/hist/physio, acquired myopathy/congenital myopathy/neoplasia, symptoms+signs/eponymous, proc