EMG
What Is EMG?
If the test picks up a problem, you may be diagnosed with what is called a neuromuscular disorder.
What Is NCS?
NCS measures how fast and how strong the electrical activity is in a nerve. The test can tell whether a nerve has been damaged.
Do I Need EMG or NCS?
For many people, though, a sore wrist is caused by an injured nerve, not an injured muscle. When it’s not clear why you’re having problems with your wrist, back, legs, or other body parts, one or both of these tests may be helpful.
- Pain or cramping
- Tingling or numbness
- Muscle weakness
What do the tests reveal?
Both tests can help doctors diagnose what’s wrong with you. They can also help rule out conditions that you don’t have. EMG and NCS are helpful in diagnosing:
- Neuromuscular diseases, such as muscular dystrophy
- Nerve problems in the spine, such as a herniated disk
- Nerve problems elsewhere in the body, such as carpal tunnel syndrome
- Peripheral nerve problems in your arms or legs
- Pinched nerves
- Guillain-Barré syndrome, a disease in which your immune system attacks the nerves in your legs and arms NCS can also help your doctor see how well you’re recovering from a nerve injury.
How Do I Get Ready for the Tests?
You don’t need to do anything special before either test. Doctors do recommend that on the morning of a test, you:
- Bathe or shower, but don’t put on any lotions or moisturizers
- Avoid caffeine and sugary beverages for at least 2 or 3 hours before a test
- Don’t smoke before a test
You should also talk with your doctor about taking medications before a test. There may be certain medicines you should avoid taking until after the test.
If you have a pacemaker, you should tell your doctor before she schedules NCS or EMG.
What Happens During the Tests?
EMG and NCS are done in a hospital or office setting. They can be “outpatient procedures,” meaning you don’t stay overnight and you expect to go home the same day, or they can be done during a hospital stay.
Several types of doctors may oversee the procedures. That includes neurologists, who are doctors who specialize in the brain and nervous system. A hospital technician may be the person who actually does the NCS or EMG.
Nerve conduction study:
The technician puts electrode patches on your skin over the nerve that may be causing your symptoms. A stimulating electrode sends a mild electrical impulse to the nerve. The other electrodes record the nerve’s response.
If the signal travels at a slower rate than it should in a healthy nerve, it means the nerve is probably damaged. More tests may be needed to learn whether the nerve can become healthy again.