Electromyography (EMG) and Nerve Conduction Study
If you have muscle pain, numbness, twitching, or weakness, there could be many possible causes.
Your first step toward relief is working with experts who can correctly identify what's causing your symptoms.
University of Iowa Health Care specialists use electromyography (EMG) and nerve conduction studies to measure the electrical activity in your muscles and nerves.
When given by experienced providers, these tests show whether you have a condition that's damaging your nerves and muscles. They also show where the problem is located and how far it has progressed.
The UI Health Care EMG lab offers state-of-the-art testing technology. The lab is staffed by board-certified providers with years of experience in conducting these tests and interpreting the results.
Highly trained experts in EMG and nerve conduction studies
The UI Health Care EMG lab team has special expertise in diagnosing a wide range of conditions.
These range from compressed nerves that cause problems like carpal tunnel syndrome to complex neuromuscular diseases and related conditions.
Precise test results mean more effective treatment choices
Your testing will be monitored and evaluated by a UI Health Care neurophysiologist. These neurologists specialize in the functioning of the nervous system.
While some medical centers have non-physicians conduct these tests, all UI Health Care EMG and nerve conduction studies are overseen by a physician. This ensures a correct diagnosis and the most effective treatment plan.
When your tests are complete, your neurophysiologist will write a comprehensive report. They'll talk with you and your referring provider about what your tests showed.
Depending on the results, other UI Health Care experts might join your care team and help make your customized treatment plan.
What to expect during your tests
You'll visit the UI Health Care EMG lab to have your tests.
An EMG and nerve conduction study are usually performed together. When you're having both, you'll have the nerve conduction study first.
The amount of time the tests take will depend on what you're being tested for. Most testing lasts between 30 and 90 minutes. You'll be seated or lying down for the tests.
Your nerve conduction study
A nerve conduction study shows how well and how fast your nerves transmit signals. You might hear this test referred to as NCS, NCV, or nerve conduction velocity.
- A technician will tape or glue electrodes to your skin over the nerves to be tested. These stimulating electrodes send out a mild electrical pulse.
- They'll place another type of electrode on the muscles that those nerves control. These electrodes record your muscles' response to electrical stimulation from the nerve.
- You'll feel a small, painless pulse of electricity through the stimulating electrodes. This stimulates the nerve to send a signal to the muscle.
- The testing equipment records the time it takes for your muscle to respond to the nerve signal.
An EMG, or electromyogram, shows how your muscles respond to nerve signals.
- A provider will place a thin wire, called a needle electrode, into the muscle to be tested. A mild electrical current flows through the electrode.
- The EMG machine records your muscle's activity while at rest.
- You'll be instructed to slowly contract the muscle. The machine records this activity.
- You may feel some discomfort during the test, and the muscles that were tested might feel sore for a few hours.
Conditions diagnosed by EMG and nerve conduction studies
EMG and nerve conduction studies are used to diagnose a wide range of conditions that affect muscles and nerves, including:
- Amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease)
- Carpal tunnel syndrome
- Charcot-Marie-Tooth disease
- Diabetic neuropathy
- Guillain-Barré syndrome
- Herniated disc
- Motor neuron disease
- Muscular dystrophy
- Myasthenia gravis
- Peripheral neuropathy
- Peroneal neuropathy
- Radial neuropathy
- Ulnar neuropathy