Electromyography (EMG) is a diagnostic procedure used to assess the health of muscles and the nerve cells that control them. During an EMG, a small needle electrode is inserted into specific chosen muscles to record the electrical activity there. This can help to identify muscle dysfunction, nerve dysfunction, or problems with nerve-to-muscle signal transmission. EMG is often performed alongside a nerve conduction study to provide a comprehensive view of a patient’s nerve and muscle function.
During an EMG, a doctor inserts a thin needle electrode through your skin into the muscle. This electrode listens in on the electrical “chatter” happening in your muscle when it’s at rest and when it’s asked to contract. This can help your doctor determine if there is any miscommunication or problems related to your nerves or muscles.
A doctor may request an electromyography (EMG) test if patients complains of muscle weakness, pain, cramps or twitching. The doctor will first evaluate the patient clinically with a medical history and physical assessment. The doctor will then have a better idea there are problem and conditions of muscle or nerve disorders that needs to be further evaluated with a nerve conduction study and/or electromyography. Some of the common muscle and nerve conditions that EMG can be useful as in investigation includes muscle disorders (myopathies), nerve disorders (neuropathies), motor neurone disease (example amyotrophic lateral sclerosis), myasthenia gravis, peripheral neuropathy or radiculopathy (nerve root compression).
To note that the EMG is often performed in conjunction with NCS, and is rarely performed in isolation. This is because the combination of NCS and EMG will give a better diagnostic value and comprehensive assessment of nerve and muscle function.
NCS and EMG can also be used as preoperative assessment. This is especially so if the surgical procedures involve nerves or muscles. The EMG may be performed to evaluate the function and integrity of the muscles and nerves involved, and for a comparison post surgery.
Electromyography (EMG) is generally considered a safe procedure when performed by a trained healthcare professional. It is a minimally invasive procedure that involves the insertion of small, fine needles into the muscles. The needles are typically sterile and disposable to minimize the risk of infection. The procedure is generally well-tolerated by most individuals, and any discomfort experienced during the test is typically minimal.
However, as with any medical test, there are potential side effects and complications to be aware of. Some patients may experience soreness and minor bruising at the needle insertion sites after the EMG. This discomfort is usually temporary and resolves within a few days. While rare, there is a potential risk of infection at the needle insertion sites. In rare cases, insertion of the needles may cause minor bleeding or the formation of a hematoma (a localized collection of blood). These occurrences are usually minimal and resolve on their own.
There is also a very small risk of nerve injury associated with the needle insertion during the EMG. This risk is minimized when the procedure is performed by a skilled professional.
The overall risk of complications during an EMG is quite low, and the procedure test is generally considered safe. It is recommended to let the doctor knows beforehand of any bloodborne infection, bleeding medical conditions or medications that one is taking.