Electromyogram (EMG) and Nerve Conduction Studies

EMG (Electromyography), Nerve Conduction Studies

Why It Is Done

An electromyogram (EMG) is done to:

• Find diseases that damage muscle tissue, nerves, or the junctions between nerve and muscle (neuromuscular junctions). These disorders may include a herniated disc, amyotrophic lateral sclerosis (ALS), or myasthenia gravis (MG).
• Find the cause of weakness, paralysis, or muscle twitching. Problems in a muscle, the nerves supplying a muscle, the spinal cord, or the area of the brain that controls a muscle can cause these symptoms. The EMG does not show brain or spinal cord diseases.

Nerve conduction studies are done to:

• Find damage to the peripheral nervous system, which includes all the nerves that lead away from the brain and spinal cord and the smaller nerves that branch out from those nerves. Nerve conduction studies are often used to help find nerve disorders, such as carpal tunnel syndrome or Guillain-Barré syndrome.

Both EMG and nerve conduction studies can help diagnose a condition called post-polio syndrome that may develop months to years after a person has had polio.

Go to previous section	Go to top of page	Go to next section
Author:	Monica Rhodes	Last Updated: July 29, 2008
Medical Review:	Anne C. Poinier, MD - Internal Medicine Colin Chalk, MD, CM, FRCPC - Neurology
© 1995-2009 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.