Electromyography & Nerve Conduction Studies
To determine the cause of a patient’s pain and to develop the proper course of treatment, a physician may order electromyography (EMG) and/or nerve conduction studies (NCS).
These tests evaluate the peripheral nervous system by measuring the electrical activity of muscles and nerves. They can help diagnose a disorder of a patient’s muscles, nerves or both. These tests can be done separately, but they are usually done at the same time.
An EMG test measures the electrical activity of the muscles. NCS measure the speed and intensity of the electrical signals that travel along a nerve and the time it takes for the muscles to respond to this signal.
Muscles move when an electrical impulse from the nerve causes them to relax or contract. When injuries occur or when a patient suffers from a debilitating disease, electrical impulses can be disrupted or slowed, causing pain, tingling or weakness.
An EMG or NCS can measure this change in activity and the findings can be used to diagnose certain conditions, including carpal tunnel syndrome, pinched nerves due to injury or a ruptured disc, as well as other neuromuscular diseases and disorders.