Myopathy

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 μυο "muscle" + pathos -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 Inherited Forms 1.2 Acquired 2 Symptoms 3 Treatments 4 References 5 External links

Classes

There are many types of myopathy. ICD-10 codes are provided here where available.

Inherited Forms

• (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. Congenital myopathies include, but are not limited to:
  • (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), a rare muscle wasting disorder
• (G71.3) Mitochondrial myopathies, which are due to defects in mitochondria, which provide a critical source of energy for muscle
• (G72.3) Familial periodic paralysis
• (G72.4) Inflammatory myopathies, which 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, which result from defects in biochemical metabolism that primarily affect muscle
  • (G73.6/E74.0) Glycogen storage diseases, which may affect muscle
  • (G73.6/E75) Lipid storage disorder

Acquired

• (G72.0 - G72.2) External substance induced myopathy
  • (G72.0) Drug-induced myopathy
    • Glucocorticoid myopathy is caused by this class of steroids increasing the breakdown of the muscle proteins leading to muscle atrophy.^[2]
  • (G72.1) Alcoholic myopathy
  • (G72.2) Myopathy due to other toxic agents
• (M33.0-M33.1)
  • Dermatomyositis produces muscle weakness and skin changes. The skin rash is reddish and most commonly occurs on the face, especially around the eyes, and over the knuckles and elbows. Ragged nail folds with visible capillaries can be present. It can often be treated by drugs like corticosteroids or immunosuppressants. (M33.2)
  • Polymyositis produces muscle weaknesss. It can often be treated by drugs like corticosteroids or immunosuppressants.
  • Inclusion body myositis is a slowly progressive disease that produces weakness of hand grip and straightening of the knees. No effective treatment is known.
• (M61) Myositis ossificans
• (M62.89) Rhabdomyolysis and (R82.1) myoglobinurias

The Food and Drug Administration is recommending that physicians restrict prescribing high-dose Simvastatin (Zocor, Merck) to patients, given an increased risk of muscle damage. The FDA drug safety communication stated that physicians should limit using the 80-mg dose unless the patient has already been taking the drug for 12 months and there is no evidence of myopathy. "Simvastatin 80 mg should not be started in new patients, including patients already taking lower doses of the drug," the agency states

Symptoms

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

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, massage, and even acupuncture are all current treatments for a variety of myopathies.

References

External links

• GeneReviews/NCBI/NIH/UW entry on Myopathy with Deficiency of ISCU
• See http://neuromuscular.wustl.edu/ for medical descriptions.

Pathology: Medical conditions and ICD code (Disease / Disorder / Illness, Syndrome / Sequence, Symptom / Sign, Injury, etc.) (A/B, 001–139) Infectious disease/Infection: Bacterial disease (G+, G-) · Virus disease · Parasitic disease (Protozoan infection, Helminthiasis, Ectoparasitic infestation) · Mycosis · Zoonosis (C/D, 140–239 & 279–289) Cancer (C00–D48, 140–239) Tumor Myeloid hematologic (D50–D77, 280–289) Anemia · Coagulopathy Lymphoid immune (D80–D89, 279) Immunodeficiency · Immunoproliferative disorder · Hypersensitivity (E, 240–278) Endocrine disease · Nutrition disorder · Inborn error of metabolism (F, 290–319) Mental disorder (G, 320–359) Nervous system disease (CNS, PNS) · Neuromuscular disease (H, 360–389) Eye disease · Ear disease (I, 390–459) Cardiovascular disease (Heart disease, Vascular disease) (J, 460–519) Respiratory disease (Obstructive lung disease, Restrictive lung disease, Pneumonia) (K, 520–579) Stomatognathic disease (Tooth disease) · Digestive disease (Esophageal, Stomach, Enteropathy, Liver, Pancreatic) (L, 680–709) Skin disease · skin appendages (Nail disease, Hair disease, Sweat gland disease) (M, 710–739) Musculoskeletal disorders: Myopathy · Arthropathy · Osteochondropathy (Osteopathy, Chondropathy) (N, 580–629) Urologic disease (Nephropathy, Urinary bladder disease) · Male genital disease · Breast disease · Female genital disease (O, 630–679) Complications of pregnancy · Obstetric labor complication · Puerperal disorder (P, 760–779) Fetal disease (Q, 740–759) Congenital disorder (Congenital abnormality) (R, 780–799) Syndromes · Medical signs (Eponymous) (S/T, 800–999) Bone fracture · Joint dislocation · Sprain · Strain · Subluxation · Head injury · Chest trauma · Poisoning

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, Walker–Warburg) XR dystrophin (Becker's, Duchenne) · 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 (Thyrotoxic) · Hyperkalemic Other Central core disease Mitochondrial myopathy MELAS · MERRF · KSS · PEO Other Inflammatory myopathy M: MUS, DF+DRCT anat (h/n, u, t/d, a/p, l)/phys/devp/hist noco(m, s, c)/cong(d)/tumr, sysi/epon, injr proc, drug (M1A/3)

Systemic CT disorders (M32–M36, 710) General Systemic lupus erythematosus: Drug-induced SLE · Libman-Sacks endocarditis Inflammatory myopathy/Myositis: Dermatopolymyositis (Dermatomyositis/Juvenile dermatomyositis, Polymyositis) · Inclusion body myositis Scleroderma: Systemic scleroderma (Progressive systemic sclerosis, CREST syndrome) Overlap syndrome / Mixed connective tissue disease Other hypersensitivity/autoimmune Sjögren's syndrome Other Behçet's disease · Polymyalgia rheumatica · Eosinophilic fasciitis · Eosinophilia–myalgia syndrome · fibrillin (Marfan syndrome, Congenital contractural arachnodactyly) M: MUS, DF+DRCT anat (h/n, u, t/d, a/p, l)/phys/devp/hist noco(m, s, c)/cong(d)/tumr, sysi/epon, injr proc, drug (M1A/3)

Myopathy (M60–M63, 728.0–3,8) Pain Myalgia (Fibromyalgia) Inflammation Myositis (Pyomyositis) Lytic Muscle weakness · Rhabdomyolysis · Muscle atrophy/Amyotrophy Other Myositis ossificans (Fibrodysplasia ossificans progressiva) · Compartment syndrome (Anterior) · Diastasis of muscle (Diastasis recti) · Muscle spasm M: MUS, DF+DRCT anat (h/n, u, t/d, a/p, l)/phys/devp/hist noco(m, s, c)/cong(d)/tumr, sysi/epon, injr proc, drug (M1A/3)