A nerve conduction test, is also called a nerve conduction study (NCS), or a nerve conduction velocity test (NCV)...they all mean the same thing. Also sometimes a broader term is used when describing this test and another widely used test an EMG TEST, the term is electrodiagnostic test or testing, (pronounced Elect-trow-DIE-ag-noss-tick).
This article will focus on
nerve conduction test for carpal tunnel syndrome.
This is one of the best tests for helping your doctor diagnose your carpal tunnel symptoms. The NCS test is commonly used to determine the function and the ability of the electrical conduction of nerve impulses of your muscles. A nerve conduction test is most often used to help diagnose carpal tunnel syndrome (CTS).
However, like an EMG test, a nerve conduction test can also help detect other nerve disorders such as diabetic or peripheral neuropathy and ulnar neuropathy among others.
Unlike an EMG test that uses fine electrode needles inserted through the skin into the muscle, a nerve conduction study uses surface patch electrodes (similar to the ones used for an EKG/ECG of the heart).
These sticky electrodes are placed over the muscles and nerves that are being tested. The nerve is electrically stimulated (Doctor talk for a little shock-like sensation) by the frist electrode (furtherest up the arm) while a second electrode detects the electrical impulse "down stream" from the first.
The resulting electrical activity is recorded by the other electrodes. The distance between electrodes and the time it takes to travel between electrodes are used to calculate the speed of the impulses and is reported out as milliseconds.
There are other parts of the tests that the specialist will look at, but basically a decreased speed of transmission (or travel) indicates nerve disease. (i.e. If it takes longer than normal for the electrical impulse to travel from point A to point B, you will have an ABNORMAL NCS).
When trying to diagnose upper extremity complaints of numbness and tingling, pain radiating down the arm from the neck or arm weakness, your doctor should order BOTH an EMG and a NCS because it can help you look for other causes of your carpal tunnel symptoms.
Below you will find a checklist of sorts, these are things that should be done in order for you to get an accurate NCS. By following these few simple steps you are reducing the many variables involved when getting NCS/EMG tests. THUS, reducing your chances of getting inaccurate results!
With the way most doctor's offices operate you should have plenty of time to warm up in the lobby waiting for your appointment time!
An electrodiagnostic nerve conduction test for carpal tunnel syndrome can be a valuable tool in making the correct diagnosis, especially if done in conjuction with an EMG test.