Nerve Conduction StudyEn Español (Spanish Version)
Definition | Reasons for Test | Possible Complications | What to Expect | Call Your Doctor
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
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
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).
American Chronic Pain Association
National Institute of Neurological Disorders and Stroke
Canadian Neurological Sciences Federation
Chronic Pain Association of Canada
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.