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The EMG test (electromyography) is a method that allows the assessment of muscle function. It turns out to be useful in diagnosing many neurological diseases. Thanks to it, we will find out where pathologies are located and check what their nature is. EMG tests may also be useful in the diagnosis of sciatica and shoulder.
EMG research – what is it?
EMG tests are a type of electrophysiological tests whose main task is to assess the functioning of muscles and nerve connections. EMG is used in neurological diseases as well as in disorders of the functioning of the muscular system.
Thanks to EMG research, it is possible to locate pathology and implement appropriate treatment.
EMG examination – indications
The main indication for the EMG examination is the carpal tunnel syndrome, the tarsal canal syndrome, and the so-called tennis elbow. The examination is performed mainly in spastic and flaccid paresis. Paresis most often arise as a result of a stroke or its hypoxia caused by cardiac arrest. It happens that these palsy arise after injuries or operations on the spine. The indications for EMG tests include:
• muscular dystrophy;
• spinal muscle atrophy;
• sciatica;
• shoulder pain;
• muscle damage as a result of injuries;
• myasthenia gravis;
• neuromuscular hyperactivity disorder;
• diabetic polyneuropathy;
• Guillain-Barre syndrome.
EMG tests are often performed by athletes because they allow to assess the body’s efficiency. In addition, they help to see which techniques and exercises will be best to achieve the desired results in the chosen discipline.
EMG tests – contraindications
EMG testing should not be performed on people who have a pacemaker. Artificial valves as well as other metal elements located in the heart also disqualify the patient from the examination. Pregnancy is also an absolute contraindication.
EMG research – preparation for the test
Electromyography is not a method that requires special preparation for the examination. However, it is very important to wash the place where it will be carried out in advance. Do not lubricate the area under examination. The patient must inform the doctor about the medications taken. Some of them can significantly affect the test result. These include, for example, aspirin, as well as some dietary supplements. Occasionally you may find that you experience bleeding after insertion of the electrodes.
People with myasthenia gravis should not take anti-disease medications on the day of the test, as they may distort the test results.
EMG tests – the course of the study
The entire study can be divided into 4 parts:
• electroneurography – stimulates the selected nerve with one electrode and records the conducted impulse to the place where the second electrode is located;
• electromyography – is the study of conduction in peripheral nerves. From 10 to 20 needle electrodes are inserted into the selected muscles;
• tetany test, also known as ischemic test – to detect tetany. A needle electrode is inserted between the thumb and forefinger. During this time, a tourniquet is tightened around the selected arm, preventing blood from flowing, causing severe tingling and stiffness. The examination takes about 15 minutes. After this time, it is possible to check whether the hand has symptoms characteristic of tetany;
• myasthenic test, also known as boredom test or fatigue test – involves the stimulation of neuromuscular conduction with supramaximal stimuli. The test is not invasive as it uses surface electrodes.
EMG tests – does the patient feel pain?
The vast majority of patients worry that EMG testing is painful. Pain, however, is always an individual matter. The most unpleasant moment is when the needle electrodes are inserted. Some patients also react to the stimulation of the nerve itself. EMG examination is not the most pleasant one, but very often it is the only method that allows you to make an accurate diagnosis. Muscle contractions during the examination may be painful or cause slight discomfort. However, everything passes after the end of the trial.
There is also a completely non-invasive method of EMG examination, which consists in sticking electrodes to the patient’s body. The test itself takes about 40 minutes, and a neurological examination is necessary before it is performed.
After the test, it is possible to feel pain and tenderness at the test site, but this should subside within a few days.
EMG tests for the carpal tunnel – main indications
EMG tests are increasingly being carried out due to the carpal tunnel syndrome, which mainly affects office workers who use only the wrist muscles when performing computer tasks. Thanks to electromyography, it is possible to check for degeneration not only of the wrist, but also of the spine – another ailment that often recurs during sedentary work. The hand degenerations that should be of concern to the patient include:
• numbness and / or tingling of the thumb, index finger, middle finger and half of the ring finger;
• pain in the wrist that increases when the hand is raised and disappears when it descends;
• finger stiffness;
• mobility restriction (including items falling out of the hand);
• wrist pain at night.
Also check out: What is the treatment for carpal tunnel syndrome?
EMG research – price
The price of EMG tests is not constant, because we will pay for each of them separately from the series of four electromyography procedures. An additional variable is also the type of ailment and its extent.
For example, one side of neurography in the case of an examination for carpal tunnel syndrome, as well as an assessment of the median and ulnar nerves may cost PLN 70, and a polyneuropathy examination – PLN 170. The price for the martyrdom test is PLN 120, while the ischemic test is PLN 90.