Muscle atrophy

Jump to: navigation, search
Muscle atrophy
Muscle atrophy.jpg
Muscle atrophy.
Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology

WikiDoc Resources for Muscle atrophy

Articles

Most recent articles on Muscle atrophy

Most cited articles on Muscle atrophy

Review articles on Muscle atrophy

Articles on Muscle atrophy in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Muscle atrophy

Images of Muscle atrophy

Photos of Muscle atrophy

Podcasts & MP3s on Muscle atrophy

Videos on Muscle atrophy

Evidence Based Medicine

Cochrane Collaboration on Muscle atrophy

Bandolier on Muscle atrophy

TRIP on Muscle atrophy

Clinical Trials

Ongoing Trials on Muscle atrophy at Clinical Trials.gov

Trial results on Muscle atrophy

Clinical Trials on Muscle atrophy at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Muscle atrophy

NICE Guidance on Muscle atrophy

NHS PRODIGY Guidance

FDA on Muscle atrophy

CDC on Muscle atrophy

Books

Books on Muscle atrophy

News

Muscle atrophy in the news

Be alerted to news on Muscle atrophy

News trends on Muscle atrophy

Commentary

Blogs on Muscle atrophy

Definitions

Definitions of Muscle atrophy

Patient Resources / Community

Patient resources on Muscle atrophy

Discussion groups on Muscle atrophy

Patient Handouts on Muscle atrophy

Directions to Hospitals Treating Muscle atrophy

Risk calculators and risk factors for Muscle atrophy

Healthcare Provider Resources

Symptoms of Muscle atrophy

Causes & Risk Factors for Muscle atrophy

Diagnostic studies for Muscle atrophy

Treatment of Muscle atrophy

Continuing Medical Education (CME)

CME Programs on Muscle atrophy

International

Muscle atrophy en Espanol

Muscle atrophy en Francais

Business

Muscle atrophy in the Marketplace

Patents on Muscle atrophy

Experimental / Informatics

List of terms related to Muscle atrophy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Editor-in-Chief: Angela Botts, M.D., Beth Israel Deaconess Medical Center Geriatric Medicine [2] Associate Editor(s)-in-Chief: Cafer Zorkun, M.D., Ph.D. [3] Luke Rusowicz-Orazem, B.S.

Muscle atrophy refers to a decrease in the size of skeletal muscle, which occurs in a variety of settings. Atrophy may or may not be distinct from "sarcopenia", which is the loss of muscle seen in the aged.

When a muscle atrophies, it necessarily becomes weaker, since the ability to exert force is related to mass.

Clinical settings of atrophy

There are many diseases and conditions which cause a decrease in muscle mass, known as atrophy, including: inactivity, as seen when a cast is put on a limb, or upon extended bedrest (which can occur during a prolonged illness); cachexia - which is a "body-wasting" syndrome that is a co-morbidity of cancer and Congestive Heart Failure; Chronic Obstructive Pulmonary Disease; burns, liver failure, etc. Other syndromes or conditions which can induce skeletal muscle atrophy are congestive heart disease, liver disease, and starvation.


Causes

Life Threatening Causes

Common Causes

Causes by Organ System

Cardiovascular Athermoatous disease, Buerger's disease, Cerebrovascular accident, Embolism of great vessel, Foix-alajouanine syndrome , Ischemic palsy, Lipidosis with triglyceride storage disease , Lumbar canal stenosis, Meningovascular malformations, Stroke, Thrombosis of great vessel, Vascular disease, Volkmann's contracture
Chemical/Poisoning Alcoholism, Lupine poisoning 
Dental No underlying causes
Dermatologic Burns, Dermatomyositis , Leiner disease , Leprosy , Letterer-siwe disease , Ulerythema ophryogenesis 
Drug Side Effect Cocaine, Drug use, Hexane , Medications, Penicillamine, Pergolide, Prolonged steroid therapy, Statins, Steroid use
Ear Nose Throat No underlying causes
Endocrine Adrenal dysfunction, Carnitine deficiency, Decreased appetite, Endocrine disorders, Glycogen storage myopathy, Hypercortisolism, Hyperthyroidism, Hypothyroidism, Kwashiorkor, Sandhoff disease , Thyroid disease, Thyroid dysfunction
Environmental Bed rest
Gastroenterologic Andersen disease , Andrade's syndrome , Banti syndrome , Bard-pic syndrome , Chronic diarrhoea, Glycogen storage myopathy, Hepatoma , Kwashiorkor, Malabsorption syndrome, Mitochondrial neurogastrointestinal encephalopathy syndrome , Rib tumor , Tropical sprue, Type iv glycogen storage disease 
Genetic Allan-herndon-dudley syndrome , Alves castelo dos santos syndrome , Andersen disease , Andrade's syndrome , Arthrogryposis, Bethlem myopathy , Bruyn-scheltens syndrome, Camurati-engelmann disease , Charcot-marie-tooth disease, Charlevoix-saguenay spastic ataxia, Coenzyme q 10 (coq10) deficiency , Complex 1 mitochondrial respiratory chain deficiency , Congenital disorder of glycosylation, Cutler syndrome , Cytoplasmic body myopathy , Dyskeratosis congenita of zinsser-cole-engman , Dystrophia myotonica 1 , Emery-dreifuss syndrome , Facwa syndrome , Fascioscapulohumeral, Friedreich ataxia , Fukuyama type muscular dystrophy , Furukawa-takagi-nakao syndrome, Gamstorp-wohlfart syndrome , Gangliosidosis, Jequier-kozlowski-skeletal dysplasia , Kuskokwim disease , Levine-critchley syndrome , Madsam , Marinesco-sjogren syndrome , Mc leod neuroacanthocytosis syndrome , Minicore disease , Miyoshi myopathy , Morse-rawnsley-sargent syndrome , Multicentric osteolysis, Multiminicore disease , Myotonic dystrophy, Nadh coq reductase, Neu-laxova syndrome, Nodulosis-arthropathy-osteolysis syndrome , Oculopharyngeal dystrophy, Osteogenesis imperfecta , Palmoplantar keratoderma , Pantothenate kinase-associated neurodegeneration , Parsonage turner syndrome, Passos-bueno syndrome , Pontocerebellar hypoplasia , Richards-rundle syndrome , Rud syndrome , Salvioli syndrome , Schwartz-jampel syndrome , Scleroatonic muscular dystrophy , Short chain acyl coa dehydrogenase deficiency, Singleton-merten syndrome , Small syndrome , Storm syndrome , Syringomyelia, Tay sachs , Troyer syndrome, Ulerythema ophryogenesis , Wieacker syndrome, Wieacker-wolff syndrome, Wilson's disease , X-linked mental retardation
Hematologic Diabetes, Lipidosis with triglyceride storage disease , Metachromatic leukodystrophy , Soft tissue hemorrhage, Type iv glycogen storage disease , Undiagnosed diabetes mellitus
Iatrogenic Surgical ligation of major vessel
Infectious Disease Aids wasting syndrome , Bacterial infections, Bovine spongiform encephalopathy , Coxsacki b virus, Glandular fever, Herpes zoster, Hiv, Hookworm infestation, Intestinal capillariasis , Malaria, Mycobacterium kansasii , Neurosyphilis , Parasitic infections, Polio, Post-polio syndrome, Schistosomiasis, Thyrotoxicosis, Toxoplasmosis, Trichinosis, Tropical sprue, Tuberculosis, Viral infections, Wasting syndrome 
Musculoskeletal/Orthopedic Adult progressive spinal muscular atrophy, Adult sma , Athermoatous disease, Back tumor , Becker's muscular dystrophy, Cachexia, Camurati-engelmann disease , Carpal tunnel syndrome, Cerebellar ataxia, Cervical spondylosis, Chondroblastoma , Congenital muscular dystrophy , Disuse of limb, Duchenne muscular dystrophy , Erb-goldflam , Erb's dystrophy , Fascioscapulohumeral, Foix-alajouanine syndrome , Fosmn syndrome , Fukuyama type muscular dystrophy , Furukawa-takagi-nakao syndrome, Gamstorp-wohlfart syndrome , Hematomyelia, Hereditary inclusion body myopathy , Hereditary peripheral nervous disorder , Herniated disk, Hip cancer , Hypertrophic neuropathy of dejerine-sottas , Immobility, Immobilized fractures, Inclusion body myopathy , Inclusion body myositis , Joint disuse , Joint inflammation, Joint injuries, Kuskokwim disease , Lambert-eaton myasthenic syndrome , Landouzy-dejerine muscular dystrophy , Legg-calve-perthes disease , Letterer-siwe disease , Limb-girdle muscular dystrophy type , Lumbar canal stenosis, Lumbar spondylosis, Meniscal tear, Mitochondrial myopathy , Motor neuropathy , Muscle disuse, Muscle injury, Muscular dystrophy , Muscular fibrosis, Muscular phosphorylase kinase deficiency , Myasthenia, Myasthenic syndrome, Myopathy , Nadh coq reductase, Nemalin myopathy, Nodulosis-arthropathy-osteolysis syndrome , Osteoarthritis, Osteogenesis imperfecta , Paralysis of limbs, Polymyositis, Posterior column ataxia , Primary biliary cirrhosis , Primary lateral sclerosis , Primary muscle disease , Progressive spinal muscular atrophy , Prolapsed lumbar intervertebral disc, Prolonged immobilization, Proximal spinal muscular atrophy, Salvioli syndrome , Soft tissue edema, Soft tissue hemorrhage, Spinal cord injury, Spinal cord lesion, Spinal cord tumor, Spinal muscular atrophy , Spinal tumor, Spinocerebellar ataxia , Subacute combined degeneration of the spinal cord, Syphilitic amyotrophy, Syringomyelia, Thoracic outlet syndrome , Vacuolar myopathy , Volkmann's contracture, Welander distal myopathy
Neurologic Adult sma , Alcoholic neuropathy , Amyotrophic lateral sclerosis , Arachnoiditis , Ataxia, Balo's concentric sclerosis , Bovine spongiform encephalopathy , Cerebellar ataxia, Cerebrovascular accident, Charcot-marie-tooth disease, Creutzfeldt-jakob disease, Cytoplasmic body myopathy , Damage to nerve supplying muscle, Decreased appetite, Degenerative motor system disease , Diabetic neuropathy, Erb-goldflam , Erb's dystrophy , Fosmn syndrome , Friedreich ataxia , Generalized myasthenia gravis , Hematomyelia, Hereditary peripheral nervous disorder , Hypertrophic neuropathy of dejerine-sottas , Inclusion body myopathy , Inclusion body myositis , Intercostal neuralgia , Ischemic palsy, Lower motor neurone lesion, Madsam , Meningovascular malformations, Mental retardation, Mitochondrial encephalomyopathy , Mitochondrial neurogastrointestinal encephalopathy syndrome , Motor neurone disease, Motor neuropathy , Multifocal motor neuropathy , Multiple sclerosis, Nerve compression, Nerve entrapment , Nerve injury, Neurodegeneration , Neuropathy , Neurosyphilis , Olivopontocerebellar atrophy i , Paralysis of limbs, Parkinson's disease, Parsonage turner syndrome, Peripheral nerve trauma, Peripheral neuritis , Peripheral neuropathy, Polyradiculoneuropathy , Pontocerebellar hypoplasia , Posterior column ataxia , Primary biliary cirrhosis , Primary lateral sclerosis , Primary muscle disease , Progressive spinal muscular atrophy , Prolapsed lumbar intervertebral disc, Prolonged immobilization, Proximal spinal muscular atrophy, Radiculopathy, Reflex sympathetic dystrophy syndrome, Small syndrome , Spinal bulbar motor neuropathy , Spinocerebellar ataxia , Thyrocerebral-retinal syndrome , X-linked mental retardation
Nutritional/Metabolic Diabetes, Diabetic neuropathy, Malnutrition, Marasmus , Muscular phosphorylase kinase deficiency , Obal syndrome , Protein deficiency, Undiagnosed diabetes mellitus
Obstetric/Gynecologic No underlying causes
Oncologic Back tumor , Chondroblastoma , Hepatoma , Hip cancer , Intramedullary astrocytoma, Intramedullary ependymoma, Malignancy, Rib tumor , Spinal cord tumor, Spinal tumor
Ophthalmologic Incontinentia pigmenti , Intestinal capillariasis , Obal syndrome , Thyrocerebral-retinal syndrome 
Overdose/Toxicity Alcoholic neuropathy , Alcoholism
Psychiatric Anorexia nervosa 
Pulmonary Embolism of great vessel, Sarcoidosis, Tuberculosis
Renal/Electrolyte Chronic kidney disease , Lightwood-albright syndrome, Nephrotic syndrome 
Rheumatology/Immunology/Allergy Ankylosis , Arthritis, Arthrogryposis, Buerger's disease, Cachexia, Carpal tunnel syndrome, Cervical spondylosis, Cushing's disease, Dermatomyositis , Juvenile rheumatoid arthritis , Lambert-eaton myasthenic syndrome , Landouzy-dejerine muscular dystrophy , Leprosy , Lumbar spondylosis, Muscular fibrosis, Osteoarthritis, Polyarteritis nodosa, Rheumatoid arthritis, Sarcoidosis, Wohlwill-andrade syndrome 
Sexual Aids wasting syndrome , Hiv, Syphilitic amyotrophy, Wasting syndrome 
Trauma Burns, Damage to nerve supplying muscle, Herniated disk, Immobilized fractures, Joint injuries, Meniscal tear, Muscle injury, Nerve compression, Nerve entrapment , Nerve injury, Peripheral nerve trauma, Spinal cord injury, Spinal cord lesion, Subacute combined degeneration of the spinal cord, Tourniquet paralysis
Urologic No underlying causes
Miscellaneous Multiple system atrophy , Old age

Causes in Alphabetical Order

Other muscles diseases, distinct from atrophy

During aging, there is a gradual decrease in the ability to maintain skeletal muscle function and mass. This condition is called "sarcopenia". The exact cause of sarcopenia is unknown, but it may be due to a combination of the gradual failure in the "satellite cells" which help to regenerate skeletal muscle fibers, and a decrease in sensitivity to or the availability of critical secreted growth factors which are necessary to maintain muscle mass and satellite cell survival.

In addition to the simple loss of muscle mass (atrophy), or the age-related decrease in muscle function (sarcopenia), there are other diseases which may be caused by structural defects in the muscle (muscular dystrophy), or by inflammatory reactions in the body directed against muscle (the myopathies).

Pathophysiology

Muscle atrophy occurs by a change in the normal balance between protein synthesis and protein degradation. During atrophy, there is a down-regulation of protein synthesis pathways, and an activation of protein breakdown pathways. The particular protein degradation pathway which seems to be responsible for much of the muscle loss seen in a muscle undergoing atrophy is the "ATP-dependent, ubiquitin/proteasome pathway. In this system, particular proteins are targeted for destruction by the ligation of at least four copies of a small peptide called ubiquitin onto a substrate protein. When a substrate is thus "poly-ubiquitinated", it is targeted for destruction by the proteasome. Particular enzymes in the ubiquitin/proteasome pathway allow ubiquitination to be directed to some proteins but not others - specificity is gained by coupling targeted proteins to an "E3 ubiquitin ligase". Each E3 ubiquitin ligase binds to a particular set of substrates, causing their ubiquitination.

Diagnostic Findings

Potential treatment

Muscle atrophy can be opposed by the signaling pathways which induce muscle hypertrophy, or an increase in muscle size. Therefore one way in which exercise induces an increase in muscle mass is to downregulate the pathways which have the opposite effect.

See also

External links


Linked-in.jpg