What is an EMG/NCV study?
Electromyography (EMG) and Nerve Conduction Velocity (NCV) studies are ordered to evaluate nerve and muscles disorders. Nerve conduction studies evaluate the function of the nerve by stimulating nerves and seeing how the impulses conduct across segments of the nerves. Electromyography evaluates the function of the muscle and the connection of the nerves to muscles. These studies should be considered an extension of a history and physical exam.
How is this test performed?
The person conducting the test will put little sticky electrodes on your arm or leg, and stimulate various nerves. To you, the stimulation's will feel like little shocks. This is the nerve conduction portion of the exam. The EMG portion is done by placing a very thin specialized needle one at a time into different muscles. The needle is not hollow, and nothing is being injected into the muscle. The needle is used to record or listen to your muscle activity. The test typically takes less than an hour.
Why was this test ordered?
Are you experiencing symptoms, such as pain, numbness, tingling, weakness, muscle cramping in the arms or legs? Your doctor may want to evaluate for an injury to a nerve that can occur with various conditions, such as:
- Radiculopathy in the cervical or lumbar spine – pressure on the nerves roots as they exit the spinal column. In the lumbar spine the symptoms of numbness and tingling radiating into a leg is often called sciatica.
- Brachial and lumbosacral plexopathies.
- Peripheral neuropathies.
- Entrapment neuropathies