Muscular dystrophy is a group of inherited, progressive muscle disorders. All forms cause progressive weakness and degeneration of the muscles that control movement. Some also affect the heart or other organs. Age of onset is between infancy to adulthood. The different forms include:
- Duchenne dystrophy (the most common)
- Becker (a milder form than Duchenne)
- Myotonic muscular dystrophy (can have its onset in late adulthood)
This condition is caused by defects in genes that control muscle development and function. In some cases, the genes are passed from parent to child. In other cases, the genetic mutation occurs spontaneously.
These factors increase your chance of developing muscular dystrophy. Tell your doctor if you have any of these risk factors:
- Family member with muscular dystrophy
- Sex: male for some types (Duchenne and Becker)
Symptoms common to most forms of muscular dystrophy may include:
- Progressive weakening of muscles—Usually, those muscles closest to the trunk become weak first. Then, muscles further away weaken as the disease advances.
- Enlargement of muscles as they weaken
- Frequent falling and difficulty getting up
- Severe muscle deterioration, usually leading to use of a wheelchair
- Distortion of the body
- Muscle contraction and stiffening (often severe)
- Difficulty breathing
Severe Muscle Contraction of the Hand
Symptoms specific to Duchenne and Becker dystrophy include:
- Abnormally curved spine
- Enlargement and weakening of the heart muscle
- Pneumonia]]> and other respiratory infections
Symptoms specific to myotonic muscular dystrophy include:
- Difficulty in letting go after a handshake
- Muscle weakness that affects the central nervous system, heart, digestive tract, glands, or eyes
Symptoms usually become progressively worse. In many forms, life expectancy is shortened.
The doctor will ask about your symptoms and medical history. She will also do a physical exam.
Tests may include:
- Muscle tissue biopsy]]> —removal of a sample of muscle tissue for testing
- Blood enzyme tests—testing a blood sample to look for elevated enzyme levels
- Genetic testing-using blood samples
- ]]>Electromyogram (EMG)]]> —measures electrical impulses coming from muscles
- ]]>Nerve conduction study (NCS)]]> —measures electrical impulses in the nerves
There is no cure. However, treatment may help improve the symptoms.
Treatment may consist of:
Physical Therapy and Exercise
Physical therapy and exercise can help prevent the muscles from permanently contracting and stiffening.
In earlier stages, wearing braces may improve your ability to move around. A back brace may slow curvature of the spine.
Medications may include:
- Corticosteroids to relieve muscle weakness (chronic steroids can also cause muscle injury called “steroid myopathy”)
- Creatine]]> supplements (shown to reduce fatigue and increase strength in some studies)
- Drugs for heart problems if muscular dystrophy affects the heart
In severe cases, surgery may be needed to release muscles that are painfully tight. If there are heart problems, a ]]>pacemaker]]> may be needed.
Other treatments are being studied.
Muscular dystrophy is an inherited disease. Get genetic counseling if you are concerned about having a child with muscular dystrophy, especially if you:
- Have muscular dystrophy or a family history of the disease
- May be a carrier of the gene for muscular dystrophy
- Have a partner with a family history of the disease
Muscular Dystrophy Association
Muscular Dystrophy Family Foundation
Parent Project Muscular Dystrophy
Canadian Institute of Health Research
Muscle Dystrophy Canada
Beer MH, Fletcher AJ, et al. The Merck Manual of Medical Information . 17th ed. Simon and Schuster, Inc; 2000.
Creatine. EBSCO Health Library, Natural and Alternative Treatments website. Available at: http://www.ebscohost.com/thisTopic.php?marketID=15topicID=81 . Updated November 2008. Accessed March 5, 2008.
Duchenne muscular dystrophy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated January 31, 2008. Accessed February 23, 2008.
Kasper DL, Braunwald E, Fauci AS, et al. Harrison's Principles of Internal Medicine . 16th ed. New York, NY: The McGraw-Hill Companies; 2005.
Moxley RT, Heatwole C. Myotonic Dystrophy. In: Gilman S, ed. MedLink Neurology . San Diego, CA: MedLink Corporation. Available at: http://www.medlink.com . Accessed March 16, 2007.
Muscular Dystrophy Association website. Available at: http://www.mdausa.org .
NINDS muscular dystrophy information page. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/ . Updated January 27, 2009. Accessed February 6, 2009.
Last reviewed January 2009 by ]]>Rimas Lukas, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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