¿La electromiografía causa dolor? Explorando este procedimiento

The electromyography or EMG not only helps in diagnosis, but it can also be useful in planning treatment and monitoring the progression of neuromuscular diseases. It is a test that clinical neurophysiologists usually perform and there are many doubts about whether it causes pain in patients or not.

Therefore, we interviewed the neurophysiologist and secretary of the Spanish Society of Clinical Neurophysiology (SENFC) Diego Rodríguez Mena, who explains that this technique is used to detect and analyze the electrical signal that is generated when a muscle contracts, and therefore can evaluate the muscle function and the communication between the nerves and muscles of the person.

«The electromyographic signal allows the construction of the electromyogram, which corresponds to the temporal and spatial amount of action potentials of the motor units (MU) during contraction, allowing for precise and objective quantification of the muscular bioelectric behavior,» he adds.

Therefore, this specialist states that electromyography consists of direct recordings of muscle activity, both at rest and during contraction, by inserting a needle electrode into various muscles: «A feeling of puncture when the needle is inserted and sometimes a dull pain while the needle is placed. Electric currents are generally not applied. The EMG captures the electrical activity generated by the muscles. This activity appears on a screen and is reproduced by a speaker so that the doctor can see and hear it.»

As indicated, most patients describe EMG as «more uncomfortable than painful» because the insertion of needle electrodes can cause a feeling of puncture or cramps; although the SENFC Secretary insists that it is usually short-lived. «The discomfort varies depending on the patient’s sensitivity and the location of the muscle being evaluated.»

During the test, this spokesperson for neurophysiologists asserts that patients should feel comfortable, communicating any concerns or questions before and after the test; as this can help reduce anxiety and improve the overall experience.

With this, Diego Rodríguez Mena emphasizes that electromyography is a valuable technique in the diagnosis of many neuromuscular diseases, as well as disorders related to the peripheral nervous system, as it allows for the evaluation of the electrical activity of muscles and nerves, which can help identify the presence of muscle damage or dysfunction.

«I would recommend an EMG when there is a suspicion of neuromuscular disorders or when other studies have not provided a clear diagnosis. EMG is particularly useful for evaluating muscle function and communication between nerves and muscles, which may not be obvious in other tests,» insists this expert.

The duration of EMG may vary, according to Rodríguez Mena, although he emphasizes that it usually takes about half an hour. «During the test, the patient may be asked to perform specific movements or contract the muscles for a more comprehensive evaluation. It is important for the patient to follow the technician’s instructions to achieve accurate results,» he adds.

In the opinion of the SENFC Secretary, prior body hygiene is essential, and no lotions, oils, or moisturizing creams should be used. «It is not necessary to be fasting and no additional training is required,» he points out.

In fact, this expert indicates that the patient can take their usual medications; he also warns that, before the start of the study, the skin temperature will be checked, and if it is lower than correct, the area to be studied will be warmed up to avoid errors in interpreting the results obtained. «Also, it is important to inform your doctor about any medications you are taking, especially anticoagulants and any relevant medical conditions,» he concludes.

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