Frequently Asked Questions About Electromyography

Electromyography (EMG) is an examination method in which the electrical conduction functions of nerves are measured by using a linear electrical current at a level that will not cause too much discomfort to the patient. For this purpose, a low-intensity electrical current is applied to the fingers and to skin areas over the nerves, and this current is collected from the nerve or another area of the skin by computerized devices and measured. Thus, it is understood whether the nerve is functioning properly. EMG examination is performed by a Neurology specialist trained in electrophysiological examination.

EMG consists of two parts. In the first part, where the conduction speed in the nerves is measured, a very mild electrical stimulus is given to the relevant nerve with the help of electrodes placed on the muscles, and the conduction speed in the nerves is calculated. In the second part, very thin and specially designed needles are inserted through the skin into the muscles to be examined, and their electrical activity is evaluated. Needle electrodes are used in EMG examination for the diagnosis of problems in the muscles. Therefore, it is also called needle EMG. They have been turned into recording electrodes by placing a very thin wire inside specially prepared needles. When a needle connected to the device is first seen, it may create a fear that electricity will be given. However, no electrical stimulus is given during needle EMG examination. It is only used to record normal or abnormal electrical activity in the muscles. The tip of the needle is placed directly into the muscle being investigated. The electrical activities generated by the signals sent from the brain to contract that muscle in the muscle region close to the needle tip are amplified by very special devices and monitored on the screen of the device. In addition to visual examination, the same signals are made audible through a speaker, and this makes an important contribution to the evaluation of the physician performing the examination.

It is always necessary to examine more than one nerve and muscle in one body region. Since the method may be painful due to the way it is applied, the practitioner avoids unnecessary procedures by limiting the examination with the help of knowledge and experience. Sometimes examinations that seem limited and are planned to be short may be expanded according to the data obtained during the procedure. Since separate examination plans suitable for each patient’s disease are applied in EMG, it is difficult to speak of a standard examination duration, but this period may range from 30 minutes to 2 hours. During this period, the patient helping the doctor as much as possible will make the examination healthier and prevent unnecessary prolongation.

Nerve injuries (nerve cuts, traffic accidents, etc.) Nerve entrapments (carpal tunnel syndrome, etc.) In the diagnosis of cervical and lumbar disc herniations Investigation of the effects of diseases that may impair nerve functions (such as diabetes and kidney disease) on the nerves, Diagnosis and follow-up of facial paralysis Diagnosis of muscle and neuromuscular junction diseases (myasthenia, myopathy, etc.) In the diagnosis of spinal cord diseases associated with muscle wasting (ALS, polio, etc.)

EMG examination cannot be performed without ensuring appropriate conditions in patients who use a pacemaker, blood thinners (coumadin, aspirin, etc.), and who have bleeding-clotting disorders. This is because in EMG examinations performed in areas close to the pacemaker, the pacemaker settings may be disturbed, or intramuscular bleeding may occur during needle EMG due to blood-thinning medication.