Nerve Electrical Studies
In order to better understand some disease processes, your doctor may order a kind of study which will help to make an accurate diagnosis. Understanding the way that nerves within the body are functioning and responding to electrical stimulation can help to see the whole picture in treating pain, muscle weakness, numbness and other medical conditions.
There are several kinds of nerve electrical studies performed in our offices.
EMG – or Electromyogram Test
Muscles respond to and emit electrical impulses. In a healthy body, these impulses follow regular patterns that can be measured using small electrodes during an electromyogram test (EMG).
- Intramuscular EMG – Involves insertion of a needle electrode into the muscle being measured. It is the most direct way of measuring electrical activity within muscle cells
- Surface EMG – Electrodes are place on the skin directly over muscles being measured
NCV – or Nerve Conduction Velocity Test
In the nerve conduction velocity (NCV) test, a nerve is electrically stimulated by one electrode, and other electrodes in another location measure the time it takes to register the nerve response triggered by the stimulating electrode. Measuring the distance between electrodes and the time it takes for electrical impulses to travel between electrodes helps to calculate the speed, or nerve conduction velocity (NCV). Slower speeds can indicate nerve damage or disease.
It is common to order and perform these tests at the same time, in order to better understand if the muscle tissue or the nerve cells or both are involved in a condition.