Nerve Conduction Study
A nerve conduction study (NCS) is a measurement of the speed of conduction of an electrical impulse through a nerve. It is used to assess nerve compression, damage and destruction. It usually takes around 45 minutes for the test. During the test, the nerve is stimulated, usually with surface electrode patches attached to the skin. Two electrodes are placed on the skin over the nerve. One electrode stimulates the nerve with a very mild electrical impulse and the other electrode records it. The resulting electrical activity is recorded by another electrode. This is repeated for each nerve being tested. The nerve conduction velocity (speed) is then calculated by measuring the distance between electrodes and the time it takes for electrical impulses to travel between electrodes. A related procedure that may be performed is electromyography (EMG). An EMG measures the electrical activity in muscles and is often performed at the same time as NCS. Both procedures help to detect the presence, location, and extent of diseases that damage the nerves and muscles.
Before you have the test, you should:
- Remove any jewellery, as this will make it easier for the electrophysiologist to attach the electrodes. Leaving your jewellery at home is also a better way of keeping it safe.
- Wear clothing with short sleeves and/or loose clothing e.g. loose trousers or a skirt, as this will make it easier if we need to look at your legs or arms.
- Avoid using lotions and creams before your test as cream or lotion on your skin can make it difficult for us to attach the electrodes.
- Eat and take any medication as normal. It is helpful if you bring a list of your current medications with you.
Nerve conduction study: http://www.healthline.com/health/nerve-conduction-velocity#overview1