Procedure Info

Electroencephalography | Electromyography | Lumbar Puncture

 

 

 

ELECTROMYOGRAPHY AND NERVE CONDUCTION STUDIES

Testing your Muscle and Nerve Function
WHAT ARE THESE TESTS?

Electromyography (EMG) and nerve conduction studies (NCS) are tests that measure muscle and nerve function. In most cases, both tests are performed. NCS is most often done first.

During NCS, mild electrical currents are applied to the skin on some parts of your body. This is done to see how quickly impulses travel between nerves. EMG assesses muscle function. To do this, a fine needle is placed under your skin into the muscle being tested. This is repeated on other muscles. The needle allows the electrical activity in your muscles to be measured. No electrical currents are applied with the needle.

During each test, wavy lines (waveforms) appear on a screen or paper. These lines show how well your nerves and muscles work. These waveforms help to determine your test results.

BEFORE YOUR TEST

Prepare for your test as instructed. Shower or bathe, but don't use powder, oil or lotion. Your skin should be clean and free of excess oil. Wear loose clothes. However, know that you may be asked to change into a hospital gown. The entire test will take about 1 hour. Be sure to allow extra time to check in.

LET YOUR TECHNOLOGIST KNOW

For your safety and the success of your test, tell the technologist if you:

  • Have any bleeding problems
  • Take blood thinners or other medications, including aspirin
  • Have any immune system problems
  • Have had neck or back surgery

You may also be asked questions about your overall health.

DURING YOUR TEST

You will be asked to lie on an exam table with a blanket over you. You may have one or both of the following:

Nerve Conduction Study (NCS)
Small metal disks (electrodes) will be attached to your skin on the area of your body being tested. This will be done using water-based gel or paste. A doctor or technologist will apply mild electrical currents to your skin. Your muscles will twitch. The test will not harm you. Currents may again be applied to the same area or the test may continue on other parts of your body.
Electromyography (EMG)
Most of the electrodes will be removed for the EMG. The doctor will clean the area being tested with alcohol. A fine needle will be inserted into the muscles in this region. When the needle is inserted, you may feel as if your skin is being pinched. Try to relax and do as instructed.
AFTER YOUR TEST

When your test is done, all of the electrodes will be removed. You can get right back to your normal routine. If you feel tired or have some discomfort, take it easy. If you were told to stop taking any medications for this test, ask when you can start taking them again. Your doctor will let you know when your test results are ready.

 

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