This noninvasive, outpatient exam is used to measure how quickly nerves conduct electrical signals through the body. NCS is a valuable technique for diagnosing nerve damage. If damage exists, NCS can help a physician find its source. Nerve conduction studies are often performed with an electromyography (EMG) exam inside The NeuroMedical Center’s Neurodiagnostic Laboratory located on the 4th floor.
WHAT TO EXPECT:
Once arriving for your EMG or NCS, you will be asked to change into a gown and lie down on an exam table.
- NCS- To perform this test, a technologist will attach two patch-like electrodes on your skin over the selected nerve with a special paste. One electrode will stimulate the nerve with a mild impulse, while the other records the electrical activity. You will experience a small tingling sensation, much like your foot falling asleep. The stimulation of the nerve and the detected response will be displayed on a monitor for the neurologist to interpret.
- EMG- Your neurologist will clean the area to be tested with an alcohol pad. A fine needle will be inserted through the skin into the selected muscle. While there will be some discomfort associated with this test, try to relax. You may be asked to tighten (contract) the muscle slowly and steadily. The physician will determine if the muscle is working normally by evaluating activity seen and heard on the EMG monitor that is connected to the electrode by wires.
When EMG and NCS are performed together, the entire series of tests normally takes 40-60 minutes to complete.
BEFORE YOUR EXAM:
Your physician may instruct you to stop taking certain medications, including warfarin and aspirin.
- Refrain from consuming caffeine or alcohol.
- Shower or bathe, but do not use any powder, lotion, or oil on your skin.
AFTER YOUR EXAM:
After an NCS, you will be free to resume normal activities. You should not experience any pain, as the electrical pulses are too low to cause injury.
After your EMG, the places where a needle was inserted into the skin are cleaned You may be sore and feel a tingling in your muscles that may last for up to 2 days. Wrap ice or cold pack with a thin towel and place on top of the sore area for 10-20 minutes as needed. Call your doctor if your pain gets worse, or if you experience swelling or tenderness at the needle site.
The neurologist who conducted your exam may be able to communicate some of the results of your EMG or NCS during or immediately after the exam, but a full report may take 2-3 days. You will be instructed on how to schedule a follow-up visit by your neurologist or a nurse.