Why it's doneBy Mayo Clinic staff
Your doctor may order an EMG if you have signs or symptoms that may indicate a nerve or muscle disorder. Such symptoms may include:
- Muscle weakness
- Muscle pain or cramping
- Certain types of limb pain
EMG results are often necessary to help diagnose or rule out a number of conditions such as:
- Muscle disorders, such as muscular dystrophy or polymyositis
- Diseases affecting the connection between the nerve and the muscle, such as myasthenia gravis
- Disorders of nerves outside the spinal cord (peripheral nerves), such as carpal tunnel syndrome or peripheral neuropathies
- Disorders that affect the motor neurons in the brain or spinal cord, such as amyotrophic lateral sclerosis or polio
- Disorders that affect the nerve root, such as a herniated disk in the spine
- Ropper AH, et al. Adams & Victor's Principles of Neurology. 9th ed. New York, N.Y.: The McGraw-Hill Companies; 2009. http://www.accessmedicine.com/content.aspx?aID=3641135&searchStr=electromyography. Accessed Dec. 18, 2012.
- Horowitz SH. Overview of electromyography. http://www.uptodate.com/home. Accessed Dec. 18, 2012.
- FAQ: Patient information. American Association of Neuromuscular & Electrodiagnostic Medicine. http://www.aanem.org/Education/Patient-Resources/Learn-About-an-EMG.aspx. Accessed Dec. 18, 2012.
- Overview of peripheral nervous system disorders. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/neurologic_disorders/peripheral_nervous_system_and_motor_unit_disorders/overview_of_peripheral_nervous_system_disorders.html?qt=peripheral%20nervous%20system%20disorders&alt=sh#v1045423. Accessed Jan. 15, 2013.
- Carpal tunnel syndrome fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/carpal_tunnel/detail_carpal_tunnel.htm. Accessed Jan. 15, 2013.
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- Barbara Woodward Lips Patient Education Center. About your electromyography (EMG) examination. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2008.