What is an electromyogram?
An EMG is a test that measures the electrical activity of the nerves and muscles. The study consists of two parts:
1. The first part of the test involves nerve conduction studies (NCS) that are performed by a technologist. This part measures the ability of nerves to transmit electrical impulses or messages to their respective muscles. This part involves a small and brief electrical stimulus.
An electromyogram measures the electrical activity in your muscles to determine the cause of muscle weakness, spasms, paralysis, or pain in the arms, hands, legs, feet, and face..
2. The second part of the test is called needle electrode examination, which is performed by a physician specializing in EMG. This part examines and measures the electrical activity in muscles. This involves a very thin gauge needle that acts like a microphone when inserted into the muscle. Nothing is pushed in or pulled out through the needle. A number of muscles are examined this way, based on the clinical problem.
For both parts of the test, the patient may feel some uncomfortable sensations.
Why do patients need to have these tests?
An EMG can help physicians distinguish the cause of numbness or paralysis, muscle weakness or spasms, and the cause of pain in the arms, hands, legs, feet, and face. The results will allow the ordering physician to be able to determine the course of treatment.
Things to know about an EMG at Cleveland Clinic Main Campus site and its satellites:
- Patients have both NCS and needle examination when an EMG is ordered.
- The length of stay is 2 to 3 hours for both parts of the test at all EMG sites. Please plan to stay accordingly.
- Precautions: If any of the following precautions apply, please call the Main Campus Lab at 216.444.5544, Monday through Friday, between the hours of 7:30 am to 5:00 pm. Let them know if:
- Duration of symptoms is less than 3 weeks.
- You are taking medications such as:
— Mestinon® (pyridostigmine bromide)
— Coumadin® (crystalline warfarin sodium)
— Lovenox® (enoxaparin)
- You have any bleeding disorder.
- You have any internal devices implanted (defibrillators, internal pain stimulators, deep brain stimulators, etc.).
- The patient is a child who needs sedation for the procedure.
- Patients will be asked to change into a gown but may leave undergarments on.
- Patients do not need to fast prior to this study.
- Hygiene: Bathing is recommended to make sure that there are no oils, lotions, creams, or perfume on the skin. Please do not apply any of these items before the test. This will ensure the best results during the test.
- Results are available to the ordering physician next business day.
Please call the EMG Lab at 216.444.5544 or 800.223.2273, ext. 45544 if you have any questions.
EMGs are currently available at Main Campus, Beachwood Family Health Center, Brunswick Family Health Center, Strongsville Family Health Center, Euclid Hospital, and Lakewood Hospital. For inquiries regarding sites not listed here, please call Main Campus EMG lab at 216.444.5544.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 5/17/2010...#4825