Electrodiagnostic Medicine (EMG / Nerve Conduction Studies)

If you are scheduled for an EMG/ Nerve Conduction Study, please be sure to read these important instructions.

Electrodiagnostic medicine tests the peripheral nervous system for a variety of conditions, some common, some uncommon. Two medical specialties receive training in conducting the test, Physiatrists (Physical Medicine and Rehabilitation) and Neurologists.

The testing consists of two portions: an electromyogram (EMG), and a nerve conduction study (NCS). During the electromyogram the physician uses a small, sterile, single use needle electrode to study the individual muscles. When done properly, there is some minimal discomfort, but generally no more than that experienced with the insertion of a needle during an acupuncture treatment. The EMG test is able to evaluate for primary disorders of the muscles (myopathy) as well as damage to the muscle as a result of a pinched nerve (radiculopathy). During the nerve conduction study the physician uses a small (milliampere) current to test the peripheral nerves for disorders such as diabetic neuropathy and carpal tunnel syndrome.

The test typically takes about 30-60 minutes to perform.

Common Disorders Diagnosed by EMG/NCS

1. Carpal Tunnel Syndrome

This is an entrapment of one of the nerves in the hand (median nerve). The symptoms are typically numbness in the first three to four fingers of the hand, often worse at night, and often alleviated by shaking the hand (the "wake and shake" sign).

2. Radiculopathy (Pinched Nerve)

This is an entrapment of the spinal nerve as it exits the spinal cord on its way through the vertebra and intervertebral disc. Symptoms may include tingling and numbness of the hand or foot, weakness, and or muscle atrophy.

3. Peripheral Neuropathy

A diffuse term indication that the nerves in the arms and legs are not functioning properly. The most common causes of this condition are diabetes and alcoholism. While most people know if they are alcoholics, many persons may not know they have diabetes, and a properly performed EMG/NCV can be the first test that confirms a physician's suspicion of the condition.

Less Common Conditions

1. ALS (Amyotrophic Lateral Sclerosis)

Also known as "Lou Gehrig's disease," this is a primary disorder of the spinal cord itself, and the EMG/NCV test is crucial in making the diagnosis. Symptoms of this disorder vary, and typically include patchy but widespread weakness, without any numbness or sensory loss.

2. Myasthenia Gravis

In this disorder, the body produces antibodies that affect the ability of the muscles to function properly. The symptoms may include drooping of the eyelids, and other muscle weakness, with normal sensation.

Test Day Instructions

  1. Do not use any lotion on your skin. The lotion will block the electric impulses along the skin and significantly alter the results of the test.
  2. Please do take any pain medications that you typically take. The EMG/NCV and in fact no test, can determine how much pain an individual is having. Pain medication will not alter the results of the test.

Insurance Coverage

While nearly all medical insurance plans offer coverage for the test, it's essential to remember that "coverage" does not equate to full payment. The specifics of your insurance plan may require preauthorization before the test, or the test may be subject to your plan's deductible, copay, or coinsurance. These patient obligations, if applicable, mean that you may have out-of-pocket expenses even if your insurance covers the test. Our staff will reach out to your insurance carrier to ascertain the details prior to the date of your examination. Please note that any patient responsibility (deductible/copayment/coinsurance) is due at the time of the appointment.