How passes and what is needed to prepare for the electromyography procedure

1 The essence of

technology Electromyography is a unique way of diagnosing muscle fibers, by comparing bioelectric potentials that are transmitted directly to the specified muscle share through neural channels. All data is read by means of needle sensors that impart pulses to the electromyograph, and that, in turn, displays the image on the oscilloscope. Comparing the reference picture of the electromyogram with the received, the doctor makes a conclusion about the presence of physiological abnormalities in the work of the muscular system.

The main information that electromyography gives is the amplitude of oscillations in the potential of muscle fibers. If it is too low, then this is considered the primary sign of the presence of any pathologies in the work of the human neural system. The whole technology is just tied on the fact that the muscles are brought into action only after the arrival of the electric pulse generated by our body and in particular by the brain. If at any stage the signal is interrupted, the muscular system simply does not receive information about the required reduction. Accordingly, the motion is not carried out. In medicine, this condition is known as paralysis. And sometimes it is very difficult to install a nerve, because of which similar violations occur in the work of the musculoskeletal system. It is the electromyography that is designed to eliminate this.

2 Indications for the appointment of the

survey The passage of electromyography is assigned in the following cases:

• complaints of the patient for pain in the muscles or joints;
• probability of myopathy;
• trauma to the neural system;
• local paralysis;
• search for the optimal zone for the introduction of botox( in muscle tissue).

Diagnostics allows you to determine the smallest changes in the power of the transmitted signal, which is important in the treatment of diseases such as epilepsy, Down's syndrome and so on.

It should be noted that most often doctors prescribe the simultaneous passage of electromyography and electroneurography. The first one allows to determine the activity of muscles during the period of tension and relaxation, and the second one detects the speed of signal transmission from the brain, as well as the permeability of impulses along neural connections.

3 Diagnostic measures

The study is conducted by a doctor using special equipment. The patient must be completely relaxed at this moment. In addition, before the procedure it is forbidden to drink coffee, use nicotine, take muscle relaxants of any category, anticoagulants. It is not recommended to conduct a study for patients who have a synthetic pacemaker or heart valve. The procedure, while absolutely safe, is still connected with the supply of short electrical signals. If there is any pathology in the work of the neural system, this can provoke a short-term contraction of the heart muscle, which is dangerous for people with cardiovascular pathologies.

In the process of electromyography, needle and skin sensors are connected to the patient. Needles are given impulses, and through the electrodes are read the indices of muscle contraction. All this is connected to the analyzer, and that, in turn, gives an image to the screen( or graphic polygraph).The data are then compared with the reference data( measured before electromyography in the patient's calm state in the supine or sitting position).

Is the procedure painful? In most cases, the patient generally does not feel anything. Only in some areas there is a slight tingling sensation, and the skin acquires a reddish tint. All these symptoms completely disappear in 2-3 hours after the study.

For more accurate data, doctors conduct diagnostics by studying paired symmetrical muscles. Thus, the pathology factor in the development of the muscle fibers of the problem zone is excluded.

4 Results of the

Study In the results of the research, the most important information is the amplitude at the onset of muscle fiber contraction and at the maximum impulse, that is, when the muscle is tense as far as possible. The difference should be about 3000 μV.If the indicator is lower, then this is a clear sign of muscle dysfunction. When a problem zone is found, an electroneurography is also conducted there. That is, the nerve fibers are examined for the signal being transmitted. This method reveals lesions of peripheral neuronal endings, amyotrophy, myotonic syndrome, Parkinsonism, and essential tremor. By the way, in the detection of suspicions of the above syndromes, electromyography must be re-assigned, since it is necessary to exclude the factor of temporary muscle dystrophy due to the action of any external stimulating factors or pharmacological agents. For this reason, the patient, who is assigned to the study, is forbidden to eat anything at all until several hours before the procedure, it is recommended to refrain from drinking.

At the end of the procedure, the doctor must give the patient a schedule of muscle contractions with explanations. By these values ​​you can consult with your doctor and establish the true cause of muscle problems.

5 Contraindications to

Contraindications for electromyography include various physical diseases, as well as violations in the work of the cardiovascular system. In some cases, patients with diabetes mellitus are also denied access to the study because of reduced blood clotting. The same applies to those patients who take medications that reduce this indicator( for example, with blood infection, leukocyte).

Not recommended for electromyography in pregnant women. And this is a fairly common problem, since during the period of gestation the child often develops a nerve impairment, accompanied by constant muscle tension and acute pain. The only way to eliminate this symptom is to solder the nerve roots. However, doctors try to prescribe this procedure only in the most extreme situations, when only thus it is possible to overcome the pain.

As for children, electromyography is not performed for those who did not turn 6 on the day of diagnosis. Before this age, the study is conducted only by a decision of the consultation with the consent of the parents. That is, doctors weigh the pros and cons. The main danger from electromyography in this case is a child's panic, because of which it is not possible to conduct a study normally.

6 Additional information

The main advantage of electromyography is that the specialist is able to simultaneously examine the muscles for the amplitude of contraction and the patency of neural channels.

Unlike other stimulators, built on the supply of continuous current through the nerve channels, electromyography does not bring any painful sensations at all. Only occasionally there are miniature bruises, traces of which completely disappear in no more than 10 days. This occurs only when needle sensors are installed in the area of ​​sensitive skin.

Plus, with the help of electromyography, you can reliably know the nature of the onset of nervous seizures( for example, epileptic ones).Scientists also found that supplying electricity with a very high frequency of signal fluctuation can provoke a total contraction of muscles. And thanks to electromyography, it was found that the pathology is due to the fact that the brain sends a wrong answer when receiving a signal from the stimulus( in our case current), involving several muscle groups. All this combined and is a fit.

Electromyography is conventionally classified into the following types:

• interference( non-systematic impulses, by which the joints are examined, since the scan occurs at the time of flexion / extension of the limbs);
• local( that is, the contraction of one particular muscle is checked for the given parameters);
• is stimulatory( aimed at the effect of the peripheral nerve).

A specific method is used when searching for a certain group of muscular dysfunction. For example, the latter is applied only when the patient has a paralyzed part of the body. Stimulation with electric pulses allows you to find out whether the nerve can transmit a signal at all when the voltage of the transmitted voltage is increased( as measured in millivolts).

The sphincter electromyography, by means of which dysfunction of the bladder is detected, is classified as a separate type. It is carried out by both external cutaneous and needle sensors. It is considered one of the most painful among such methods of research of the muscular system.