- How the Electroneuromyography exam is done
- What is it for
- What diseases does the test detect
- How to prepare for the exam
- Who should not do
- Possible risks
Electroneuromyography (ENMG) is an exam that assesses the presence of lesions that affect nerves and muscles, as can happen in diseases such as amyotrophic lateral sclerosis, diabetic neuropathy, carpal tunnel syndrome or guillain-barré disease, for example, being important to help the doctor confirm the diagnosis and plan the best treatment.
This test is able to record the conduction of an electrical impulse in a nerve and to evaluate the activity of the muscle during a certain movement and, generally, the lower or upper limbs, such as legs or arms, are evaluated.
How the Electroneuromyography exam is done
The exam is performed in 2 steps:
- Electroneurography or neuroconduction: small sensors are strategically placed on the skin to assess certain muscles or nerve paths, and then small electrical stimuli are made to produce activities on those nerves and muscles, which are captured by the device. This step can cause discomfort similar to small strokes, but which are bearable; Electromyography: a needle-shaped electrode is inserted into the skin until it reaches the muscle, to directly assess the activity. For this, the patient is asked to perform some movements while the electrode detects the signals. At this stage, there is a stinging pain during needle insertion, and there may be discomfort during the examination, which is tolerable. Learn more about electromyography.
The electroneuromyography exam is done by the doctor, and is available in hospitals or specialized clinics. This exam is done free of charge by SUS and covered by some health plans, or it can be done privately, for a price of around 300 reais, which can be quite variable, according to the place where it is performed.
What is it for
Electroneuromyography is used to diagnose certain diseases that are related to nerve impulses or electrical muscle activity, in order to plan an appropriate treatment. In some cases, it can also be useful to assess the course of the disease.
The electromyogram is not the standard exam for the diagnosis of nervous and muscular diseases, however its result is interpreted according to the patient's clinical history and neurological exam results.
What diseases does the test detect
The electroneuromyography exam studies the functioning of nerves and muscles, which can be altered in situations such as:
- Polyneuropathy, caused by diabetes or an inflammatory disease. Know what is diabetic neuropathy and how to treat it; Progressive muscle atrophy; Herniated disc or other radiculopathies, which cause spinal nerve damage. Carpal tunnel syndrome. Learn how to identify and treat this syndrome; Facial paralysis; Amyotrophic lateral sclerosis. Understand what amyotrophic lateral sclerosis is; Poliomyelitis; Change in strength or sensitivity caused by trauma or blow; Muscle diseases, such as myopathies or muscular dystrophies.
With the information obtained during the exam, the doctor will be able to confirm the diagnosis, indicate the best forms of treatment or, in some cases, monitor the severity and evolution of the disease.
How to prepare for the exam
To perform the electroneuromyography, it is recommended to go to the exam site well fed and to wear loose or easily removed clothes, such as skirts or shorts. Moisturizing oils or creams should not be used within 24 hours prior to the exam, as these cosmetics can make the electrodes stick harder.
It is important to inform the doctor if you use medications, as some, such as anticoagulants, may interfere or contraindicate the test and if you have a pacemaker if you suffer from blood disorders, such as hemophilia.
In addition, it should be remembered that electroneuromyography is usually done on both sides (both legs or arms), as it is important to compare the changes found between the affected side and the healthy side.
There are no permanent effects after the exam, so it is possible to return to normal daily activities.
Who should not do
Electroneuromyography does not pose any health risks, however, it is contraindicated for people who use cardiac pacemakers or who use anticoagulant medications, such as Warfarin, Marevan or Rivaroxaban, for example. In these cases, you must inform the doctor, who will evaluate the contraindication or what type of treatment can be done.
There are some absolute contraindications for the exam, namely: the patient's non-cooperation to perform the exam, the patient's refusal to perform the procedure and the presence of lesions in the place where the investigation would be carried out.
Possible risks
The electroneuromyography exam is safe in most cases, however there may be situations whose procedure may be at risk, such as:
- Patients being treated with anticoagulants; Blood disorders such as hemophilia and platelet disorders; Diseases that weaken the immune system, such as AIDS, diabetes, and autoimmune diseases; People with pacemakers; Active infectious lesions at the site where the test would be performed.
Thus, it is important to inform the doctor if you have any of the conditions under which it is considered a risk, in addition to the use of medications so that you can reduce the risk of complications.
