An electromyography (EMG) and Nerve Conduction Study (NCV) are specialized nerve studies that measure muscle response or electrical activity when a nerve of the muscle is stimulated. The test is typically used to detect any abnormalities in the communication between the nerves and muscles. Through the use of electrode pins inserted through the skin into the muscle (similar to acupuncture pins), electrical activity is picked up and then displayed on a screen. An EMG can measure the electrical activity of muscle during rest, during slight contraction, and during forceful contraction.
When is Electromyography and Nerve Conduction Study Used?
EMG and NCV tests are part of a thorough neurological and pain examination. Due to Dr. Morchower’s background training in Physical Medicine and Rehabilitation, he has been trained to perform and evaluate EMG’s. They are most useful when diagnosing nerve problems that typically involve the legs, arms or painful areas of the body which emanate from the spinal nerve. Conditions which frequently use EMGs include:
- Peripheral neuropathies – such as diabetic peripheral neuropathy, peripheral neuropathy, Guillain-Barré syndrome, or other injury related neuropathies
- Entrapment neuropathies – such as Carpal Tunnel Syndrome, Tarsal Tunnel Syndrome, pudendal nerve entrapment
- Radiculopathies – (i.e. Sciatica) any pain that radiates from the spine to the extremities or other parts of the body
- Various disorders of the muscles – such as muscular dystrophy
Preparation for EMG/NCV Study
- Wear Loose Fitting Clothing.
- If your legs are being tested, please bring shorts
- Do not apply any lotions or oils to your skin (including hands) on the day of the procedure
- EMG/NCV are performed in the office any typically take 30-45 minutes to complete.
- Dr. Morchower or one of his associate physicians would perform the study.
- A recording electrode is attached to the skin over the nerve to be studied with a special paste and then a stimulating electrode is placed at a specific distance away from the recording electrode.
- Once an electrode has been inserted into the muscle being tested, you may be asked to contract the muscle, for example, by lifting or bending your arm. The machine then records the action potential that the muscle creates on the oscilloscope, which provides information about the ability of the muscle to respond when the nerves are stimulated.
- The nerve is then stimulated by a mild and brief electrical shock given through the stimulating electrode. This may cause some minor discomfort for a few seconds.
- The electrical activity from the muscle being studied will be measured and a report will be created for further evaluation.
- During the procedure, an audio amplifier may also be used so that both the appearance and sound of the electrical potentials can be measured.
After the test, previous daily activities may be resumed.
*Individual Result May Vary*