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Definition | Reasons for Test | Possible Complications | What to Expect | Call Your Doctor

Definition

A nerve conduction study (NCS) is a test that measures the speed and strength of electrical activity in a nerve. The test can gather information about the structure and function of both muscle and nerve.

Electromyogram of Shoulder—Used in Conjunction with Nerve Conduction Study

Electromyogram EMG
Copyright © Nucleus Medical Media, Inc.

Reasons for Test

A NCS is most often done to:

  • Help diagnose the cause of pain, cramping, numbness, or weakness
  • Determine if nerves are working properly
  • Identify the difference between muscle and nerve disorders
  • Monitor if a nerve is recovering from injury

Possible Complications

There are no major complications associated with this test.

What to Expect

Before your procedure:

  • Make sure you talk to your doctor about the medications you are taking.
  • If you have myasthenia gravis, ask if you should take any medication before the test.
  • If directed to, avoid cigarettes, coffee, tea, and soft drinks for 2-3 hours before the test.
  • Shower the day of your test. Do not use any creams, moisturizers, or powders on your skin.

Your skin will be cleaned. Electrodes will be taped to the skin along the nerves that are being studied. A small stimulus will be used to apply an electric current that causes the nerves to activate. The electrodes will measure the current that travels down the nerve pathway. The current will be slower and weaker if your nerve is damaged. Your doctor will use the stimulus at different places to determine the specific site of the damage.

Nerve conduction studies are often done along with electromyography (EMG).

You will be able to resume your daily activities after the test is complete.

About 30-90 minutes

You will feel mild discomfort from the shocks. It should not be very painful.

Your doctor will study the information from the test. A report should be ready within a few days.

Call Your Doctor

Call your doctor if you have any questions or concerns following the test.

In case of an emergency, call for medical help right away.

RESOURCES:

American Chronic Pain Association

http://www.theacpa.org

National Institute of Neurological Disorders and Stroke

http://www.ninds.nih.gov

CANADIAN RESOURCES:

Canadian Neurological Sciences Federation

http://www.cnsfederation.org

Chronic Pain Association of Canada

http://www.chronicpaincanada.com

References:

Electrodiagnostic testing. American Academy of Orthopaedic Surgeons website. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00270. Updated October 2007. Accessed August 6, 2013.

Specialized nerve tests: EMG, NCV, and SSEP. North American Spine Society website. Available at: http://www.knowyourback.org/Pages/Treatments/AssessmentTools/SpecializedNerveTests.aspx. Updated June 16, 2011. Accessed August 6, 2013.

Spinal diagnostics: nerve conduction studies. Cedars-Sinai website. Available at: http://www.cedars-sinai.edu/Patients/Programs-and-Services/Spine-Center/Conditions-and-Treatments/Diagnostic-Studies/Spinal-Diagnostics-Nerve-Conduction-Studies.aspx. Accessed August 6, 2013.

Last reviewed August 2013 by Rimas Lukas, MD; Michael Woods, 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.