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Electrodiagnostic Testing of Nerves and Muscles
Nerve Conduction Study (NCS) & Electromyography (EMG)

NCS and nerves

  • NCS is a test that checks the function of the nerves. It provides information about nerve damage.
  • Nerves are cables that connect the spinal cord and the brain with the rest of the body.
  • Nerve damage can cause tingling, pain, loss of sensation and weakness.
  • Examples of common nerve conditions are carpal tunnel syndrome, pinched nerves at the spine, diabetic neuropathy, and many other nerve diseases and injuries.

How is NCS done?

  • The test is done while lying down on an examination table.
  • The nerve is stimulated with small electrical shocks delivered on the surface of the skin. The shocks are very brief (fraction of a second).
  • The strength of electrical shock varies, and can cause a feeling of little discomfort to moderate pain. There will be no lasting or residual pain.
  • After stimulation, the nerve responds by sending its own signal. This signal is recorded and analyzed by the computer.
  • To record the nerve signals, self-sticking tabs are attached to the skin. These tabs are electrodes connected to the computer.
  • Each nerve can be tested in about 2 to 3 minutes.
  • The electrical shocks are small and cannot cause any harm.
  • Patients who have pace makers can have the test. Please tell your doctor about your pacer for additional precautions.

EMG and muscles

  • EMG is a test of the function of the muscles. It provides information about muscle damage and about the function of the nerve that controls the tested muscle.
  • Damage of the muscle and its nerve causes weakness and atrophy (shrinking) of the muscle.
  • Weakness of muscles can be caused by nerve damage, certain medications, muscle inflammation, inherited disorders such as muscular dystrophy and many other conditions.

How is EMG done?

  • The test is done while lying down on an examination table.
  • A thin, sterile and disposable needle is inserted through the skin inside the tested muscle. This needle collects the electrical signals inside the muscle. These signals are fed to the computer for analysis.
  • The needle is very thin; much thinner than the needle used to draw blood.
  • Needle sticks cause a little discomfort but the pain is tolerable and does not last long.
  • Each muscle can be tested in about one minute or less.
  • The risk of infection and local bleeding are minimal. All precautions are taken to minimized such complications. Please tell your doctor if you take blood thinners.

Preparations

  • NCS and EMG do not require any special preparations.
  • You may drive and return back to work immediately after the test.
  • We ask that you wear loose clothing and not use any lotion on your skin before the test.

Who will do your test and why?

  • A board certified neurologist will do your test. We do not use technicians.
  • Testing nerves and muscles requires knowledge of complex anatomy and complicated diseases of nerves and muscles.
  • Testing nerves and muscles requires special training in performing and interpreting the electrical and computer information.
  • The test is highly technical and should only be performed by an experienced examiner. An inexperienced examiner may not perform a complete study or may misinterpret the results. This may lead to an incorrect diagnosis and inappropriate treatment.

Seek professional services and get your test done by a qualified neurologist. Most of our neurologists are fellowship trained in neurophysiology. We are happy to provide you with the highest quality, prompt and courteous services at AMC Neurology Group.

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