Electromyography (EMG)
An EMG (abbreviation for electromyography) is a medical device that can diagnose problems in the muscles or nerves.
The EMG clinic can perform two types of tests:
- Nerve Conduction Study
- Needle EMG
In some medical conditions the electrical activity of the muscles or nerves is not normal. Finding and describing these electrical properties in the muscle or nerve may help your doctor diagnose your condition.
EMG's may aid with the diagnosis of nerve compression or injury (such as carpal tunnel syndrome), nerve root injury (such as radiculopathy, ie: pinched nerve in the neck or lower back, diabetic & other peripheral neuropathies), and with other problems of the muscles or nerves. Less common medical conditions include amyotrophic lateral sclerosis, myasthenia gravis, and muscular dystrophy.
Electromyography (EMG) is often performed at the same time as nerve conduction studies, which aid in the diagnosis of peripheral nerve disorders.
EMG's are most often done for the following reasons:
- To diagnose the source of pain, numbness, tingling, weakness or cramping in the muscles
- To differentiate between true muscle weakness and limitations due to pain
- To determine if muscles are working properly
- To differentiate between muscular conditions and dysfunction due to nerve disorders
Risks
People usually have a small amount of discomfort during EMG testing because of pin insertion. Disposable needles are used so there is no risk of infection.
During nerve conduction studies, small electrodes are taped to the skin or placed around fingers. You typically experience a brief and mild shock.
Procedure
During the EMG test, small pins or needles are inserted into muscles to measure electrical activity. The needles are different than needles used for injection of medications. They are small and solid, not hollow like hypodermic needles. Because no medication is injected, discomfort is much less than with shots.
All tests are administered and interpreted by Dr. Raj following a history and neuro-musculoskeletal exam. Often muscle activity is monitored through a speaker during the test, which may make a popping or soft roaring noise. Testing may take 30-60 minutes.
EMG Preparation
- Take a bath or shower to remove all oil from your skin.
- Do not use body lotion or powder on the day of the test.
- On the day of the appointment please bring a list of any medications you are taking, and all insurance cards so that we can make copies. Tell doctor if you are taking aspirin, blood thinners (like Warfarin or Plavix) or have a pacemaker, or have haemophilia.
- If you have myasthenia gravis, please call your primary care physician 24-48 hours prior to your appointment and ask if you should take any medications before your EMG test.