Needle electromyography (EMG) is prescribed to patients to diagnose diseases of the musculoskeletal system. This method is widely used to determine the causes of muscle or back pain and monitor the dynamics of treatment. Needle EMG was first performed in 1907 by G. Pieper, but it began to be introduced into medicine in the mid-twentieth century. Needle electromyography in Moscow is performed on patients at the neurology clinic of the Yusupov Hospital, equipped with modern equipment.

Needle electromyography: research features

Needle EMG is based on establishing the bioelectric potentials of muscles during contraction and at rest. The essence this method consists in the fact that an electrical impulse is sent from the nerves to the muscles, causing them to contract. The passage of impulses is disrupted by disorders of the structure of the spinal cord and brain, pathologies of muscle fibers and nerves. With these deviations, the amplitude, duration and number of impulses, as well as their occurrence at rest, change.

Needle electromyography can be performed using one of the following methods:

• scanning EMG;
• EMG of muscle fiber, aimed at studying a single fiber;
• macro EMG;
• Standard needle electromyography is an invasive procedure in which a needle electrode is inserted into the muscle.

To conduct the study, you need a special device - an electromyograph, which picks up impulses using electrodes. The data received from the device is displayed on the monitor, recorded and analyzed by the program. Needle EMG allows a neurologist to determine the cause of the disorder, its degree, localization, based on these data, make a diagnosis and prescribe a set of therapeutic measures.

Needle EMG: indications and contraindications

Needle electromyography is an invasive procedure and therefore has certain indications and contraindications. The possibility of conducting the study is determined by a neurologist individually for each patient.

Electromyography is performed in the presence of symptoms characteristic of musculoskeletal diseases. musculoskeletal system, the cause of which is damage to nerve fibers, muscles, disorders motor activity. This study is used to clarify the diagnosis or monitor the effectiveness of treatment.

Needle EMG allows us to determine the causes of the following conditions:

• muscle pain that is not caused by injury or tension;
• fatigue and muscle weakness;
• seizures;
• sharp decline muscle mass.

There are practically no contraindications to the use of this diagnostic method. The limitation for examining the patient is his unconscious state, when voluntary muscle tension is impossible. Also, needle EMG is undesirable in the presence of pronounced purulent wounds, burns and non-healing ulcers.

If you are looking for a clinic where you can do a needle EMG, contact the Yusupov Hospital. During the consultation, experienced neurologists will determine ways to solve the existing problem and, if necessary, give a referral for research.

Needle electromyography: methodology

No special preparation is required before the procedure. Before undergoing needle electromyography, the subject is not recommended to smoke or consume foods that affect the nervous system, and should also stop taking a number of medications three days before the study.

The duration of the procedure is 30-60 minutes. Needle electromyography is performed using an electromyograph, electrodes that are connected to the device by wires, and a computer that records the results. The patient takes comfortable position in a chair or on a couch. The muscles that will be examined must be relaxed. Before applying the electrodes, the doctor treats the required area with an antiseptic.

The doctor first diagnoses impulses coming to the muscles in a relaxed state, then with slight muscle tension by the patient, as well as with artificial stimulation of their activity. Given diagnostic method for some patients it is painless. However, in some cases, after the study, discomfort, to eliminate which it is recommended to take painkillers or use warm compresses.

Needle electromyography in Moscow is performed at the neurology clinic of the Yusupov Hospital. To carry out diagnostics, the clinic uses only modern high-precision equipment that detects even minor impulses. The results of the study are carefully interpreted by experienced neurologists.

Needle electromyography in Moscow

The person to whom this study is assigned is in search of medical institution where to undergo needle EMG safely and according to favorable price. The right choice A neurologist and a clinic for diagnosis and treatment determines the effectiveness of therapy and the quality of a person’s life for several decades. The Neurology Clinic, part of the Yusupov Hospital, offers patients to undergo this study.

Every patient who comes to the Yusupov Hospital has access to wide range services for diagnosis, treatment of diseases and rehabilitation. The examination is carried out in comfortable rooms using high-precision equipment, since the data obtained significantly influence the diagnosis. There is a widespread belief that the diagnostic price for needle electromyography in private hospitals is significantly inflated, but in a neurology clinic its cost is affordable for patients with different financial capabilities.

In the Yusupov Hospital, each patient, in addition to the results of the study, can receive a range of services: consultation with a neurologist, individual plan treatment, therapy comfortable conditions and respectful attitude of the clinic staff.

Needle electromyography: price

The Neurology Clinic, located on the territory of the Yusupov Hospital, is a place where experienced neurologists provide consultations to clients, use modern methods diagnostics to identify diseases, develop individual treatment programs and promote the recovery of patients after illnesses.

When visiting the Yusupov Hospital, the patient receives help from qualified doctors at affordable prices. You can find out the cost of diagnostics and also make an appointment by phone.

Today we will tell you about what ENMG of the upper and lower limbs. In addition, you will learn how the procedure is carried out, in what cases it is prescribed and how much it costs.

General information

Electroneuromyography of the lower extremities (or upper) is a diagnostic method by which functions are monitored. Using electrical impulses, specialists can quickly determine the location, extent and cause of disturbances in their conduction.

What is it prescribed for?

• determination of the topic and nature of the damage, as well as the prevalence of the process itself;
• determining the degree of dysfunction or damage to the neuromuscular system;
• determination of severity pathological process.

In what cases should it be carried out?

Electroneuromyography of the lower extremities (the price of this procedure is presented below) is very often used by the attending doctor to make and clarify the diagnosis (a wide range of diseases of the nervous peripheral system). In addition, this method is used to determine the tactics of further therapy and prognosis of the development of the disease.

So, ENMG of the lower extremities is performed in the following cases:

• at traumatic injuries radial, ulnar, median, femoral, large and peroneal nerve, as well as other nerves of the human peripheral system;
• with plexopathy (that is, lesions of the nerve plexuses of the anterior spinal branches, in which sensory, trophic and movement disorders);
• for polyneuropathy of various origins:

For post-diphtheria, post-vaccination polyneuropathy;

With lead, chlorophos polyneuropathy (that is, damage to the motor fibers of the nerves);

For dismetabolic polyneuropathy, which may occur due to the presence somatic diseases, that is diabetes mellitus, diseases of the liver and kidneys, as well as the digestive canal, etc.;

For polyneuropathy that occurs against the background of vasculitis or systemic diseases connective tissues.

• neural amyotrophy;
• tunnel neuropathy;
• osteochondrosis of the spine, which is accompanied by the presence of radicular syndrome;
• syringomyelia, that is chronic disease nervous system, which is accompanied by the appearance of voids in the spinal cord.

What does ENMG of the lower extremities include?

The presented diagnostic method includes:

• hardware assessment of the functioning of sensory fibers of the peripheral system;
• neurological examination;
• hardware assessment of the functioning of motor fibers of the peripheral system;
• clarification of the degree of damage to muscle tissue and the extent of their involvement in the pathological process (carried out using a needle electrode);
• analysis of all information received, as well as writing a conclusion.

After carrying out ENMG of the lower extremities (or upper), the specialist writes a conclusion indicating the degree, localization, as well as the pathogenetic type (if any) of damage to the peripheral nervous system.

Other Applications

It should be especially noted that depending on the state individual elements the peripheral nervous system depends on the health of certain internal organs. In this regard, the presented method is very often used for diagnosing urological, endocrinological and other diseases.

What is the difference between EMG and ENMG?

Electroneuromyography includes the study of the conduction of impulses. As for electromyography, this is only a kind of registration electrical activity which occurs as a result of contraction of muscle tissue. Although in practice modern algorithm Such a study does not involve performing EMG in isolation, that is, without studying the speed of impulses along nerve fibers. That is why, when the attending doctor suggests that the patient do an electromyography, the latter can safely sign up for ENMG.

Electroneuromyography of the lower extremities: how is it done?

This procedure is carried out using special device- myograph. It records the nature of contractions of muscle tissue and the degree of conduction of nerve fibers. For this, the patient is placed on a special couch, and then sensors are placed on certain areas of his legs, which further evaluate and transmit data on neuromuscular impulses to the screen. In other words, such a device determines the state of the motor and sensory nerves of the legs, which in the future greatly facilitates the diagnosis and choice of necessary therapy.

Types of examination

Electroneuromyography of the lower extremities, the price of which directly depends on the chosen diagnostic method, is divided into three different types:

1. Needle ENMG. This procedure is based on studying the functional activity of muscle tissue. It is carried out using special needle electrodes, which are inserted directly into the muscles.
2. Superficial ENMG. This method reveals the efficiency of the passage of nerve impulses along peripheral nerve fibers. This is done using surface electrodes, which are applied to certain parts of the body and areas of the skin. This research method makes it possible to record the activity of muscle tissue during voluntary contraction.
3. Stimulation ENMG. This procedure is similar to the superficial one. However, it requires simultaneous stimulation of nerve fibers that are located at a remote distance from the recording electrodes.

Thus, the use of all three methods allows you to very quickly and reliably assess the state of the human neuromuscular system. In addition, these methods help to diagnose the stage, degree and level of the pathological process, as well as determine the existing deviation.

Duration of the procedure

Electroneuromyography is prescribed by doctors on an individual basis and depends on the (usually inconclusive) diagnosis. On average, this procedure lasts 60 minutes. In most cases, specialists at clinics where ENMG is performed use only disposable electrodes for the study. In this case, the conclusion is given to the patient on the day of the procedure itself.

Cost of electroneuromyography

How much does a procedure such as ENMG of the lower extremities cost? Price this study varies depending on what type is used:

• Stimulation standard electroneuromyography, including needle - about 3000-3500 Russian rubles.
• Extended electroneuromyography (1st degree of complexity), including needle - approximately 4,000 Russian rubles.
• Advanced electroneuromyography of the 2nd degree of complexity, including needle - about 5,000 Russian rubles.

It should be especially noted that all prices mentioned are conditional and may vary significantly in different medical institutions.

Electromyography– a method for studying the bioelectrical activity of muscles and neuromuscular transmission. Information about the activity of individual muscle fibers and their groups, obtained during EMG, makes it possible to judge the functional state of the nerve innervating these muscle fibers and to identify the level of damage to the peripheral nervous system. There are superficial, local (needle) and stimulation electromyography. The study is prescribed for myasthenia gravis, myoclonus, radiculopathy, neuropathies, injuries, Parkinson's disease, polymyositis, tunnel syndromes and many other diseases of the neuromuscular system.

Indications and contraindications

Complications

After needle electromyography, small bruises and pain may appear at the sites where the electrodes are inserted. There is a risk of developing infectious complications. In addition, after this version of the procedure, the content of some enzymes in the patient’s blood may increase: lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine phosphokinase (CPK). This is due to some damage to muscle tissue from needle electrodes and does not in any way affect the patient’s well-being, but should be taken into account when prescribing biochemical research blood shortly after the EMG.

Cost of electromyography in Moscow

The main factor influencing the formation of the cost of research is the form of ownership medical organization. Private treatment and diagnostic institutions usually offer this procedure at higher prices compared to public hospitals. Fluctuations in the cost of diagnostic manipulation in private centers may be due to the reputation of the clinic, its location, the availability of additional services and the qualifications of the diagnostician. If the patient wishes to undergo the study on the day of treatment, the price of electromyography in Moscow increases, while some institutions offer discounts at night.

Electromyography is a method for studying bioelectric processes developing in the muscles of humans and animals during various motor reactions. The method is based on recording biopotentials skeletal muscles. Recording of fluctuations in muscle potentials (Fig.) is carried out with special devices - electromyographs of various types.

Although electromyograms reflect only fluctuations in potentials that develop directly in the muscle, their qualitative and quantitative features can also be used to judge normal or pathological condition The central nervous system, which regulates all types of human motor activity. At various diseases arise various violations normal electromyogram pattern (Fig.).

Electromyogram during contraction of the common finger extensors: A - normal; B - with severe muscle paresis after; B - with parkinsonian tremor and rigid enhancement.

With myogenic disorders (myositis,) asynchronous fluctuations are observed with high frequency, shortening the duration of oscillations. In cases of advanced myogenic atrophy, there is a decrease in the amplitude of oscillations.

When denervation occurs, muscles appear pathological types fluctuations:
low-voltage (usually two- and three-phase) fibrillation potentials.

With segmental nuclear paresis and amyotrophy (damage to the motor cells of the brain stem), a decrease in electrical activity is observed, sometimes to the point of “bioelectric silence,” and the appearance of rare fluctuations in fibrillation potentials.

For suprasegmental disorders ( central palsies, hyperkinesis) a decrease in the amplitude of oscillations in the EMG of the affected muscles, asynchrony of excitation of motor cells and muscle fibers is revealed.

A comparison of electromyographic and clinical data allows us to clarify the location (localization) and severity of damage to the nervous system and muscles. Comparison of electromyograms repeatedly recorded in the same muscle helps to detect improvement (during recovery) of its functional state or deterioration (during a progressive disease), and also serves as one of the grounds for objective assessment results of the treatment.

Electromyographic data can provide significant assistance in diagnosis early stages diseases and with mild damage to the neuromotor system: the movement disorders that arise in such cases are sometimes so minor that clinical examination they are not yet detected, while electromyograms recorded by a highly sensitive device already reflect pathologically altered electrical activity of the muscles.

Electromyography is widely used not only in neurological clinics, but also in other human diseases (cardiovascular, oncological, infectious, etc.).

Electromyography (from the Greek mys, myos - muscle, grapho - I write) - registration of electrical potentials; skeletal muscles. Electromyography is used as a method for studying the normal and impaired function of the motor system in humans and animals. Electromyography includes techniques for studying the electrical activity of muscles at rest, during voluntary, involuntary and contractions caused by artificial stimuli.

Electromyography is used to study functional state And functional features muscle fibers, motor units, neuromuscular transmission, nerve trunks, segmental apparatus spinal cord, as well as suprasegmental structures; study coordination of movements, development of motor skills during various types work and sports exercises, restructuring of the transplanted muscles, fatigue. Based on electromyography, a method for controlling muscle biocurrents was created, which found practical application when controlling so-called bioelectric prostheses (see Prosthetics).

An electromyogram is a curve obtained on photographic paper, film or paper when recording the electrical potentials of skeletal muscles. It can be recorded using a special device called an electromyograph, or other devices used to record biopotentials. The device, as a rule, has at least two recording channels. Each channel includes output electrodes, a biopotential amplifier and a recording device. Most electromyographs include a device for visual and auditory monitoring (Figure 1).

Rice. 1. Diagram of the device for electromyography.

The main source of fluctuations in the electrical potential of muscles is the one spreading along muscle fibers process of excitation. However, since the electromyogram is recorded in the region of motor points (see Electrodiagnostics), part of the electrical potential is the potential that arises when the end plates are excited. Electrical potentials from skeletal muscles can be conducted intracellularly or extracellularly.

Intracellular discharge of electrical potentials of individual muscle fibers in humans makes it possible to determine those characteristics that were previously studied in microelectrode studies on animals or drugs: values membrane potentials muscle fibers, depolarization and hyperpolarization of membranes, etc. (see Bioelectric phenomena). A number of authors call the recording of intracellular potentials in skeletal muscles intracellular electromyography.

Extracellular removal of electrical potentials is carried out using two methods:
1) using electrodes with a relatively small abducting surface (hundredths of a square millimeter), immersed into the muscle using needles (Fig. 2, 1-3); Moreover, in all cases, except for unipolar lead, both lead electrodes are located at a short distance from each other (usually less than 0.5 mm); 2) using electrodes with a relatively large abductor surface (30-100 mm2), usually placed on the skin above the muscle at a relatively large distance from each other (1-2 cm) (Fig. 2, 4-6). In the first case, it is customary to talk about “local”, in the second - about “global” lead. “Local” lead makes it possible to study electrical potentials arising in a small volume of muscle tissue: the potentials of individual motor units, the total potentials of a small number of motor units, and in pathological conditions - the potentials of individual muscle fibers. The main object of study is the motor unit. This concept originally meant a set of muscle fibers innervated by one motor neuron.

Rice. 2. Needle and skin electrodes for recording electromyograms: 1 - concentric; 2 - bipolar; 3 - multielectrode (according to Buchtal); 4 - 6 - skin electrodes of various types.

Rice. 3. Fluctuations in muscle potential during “local” abduction: 1 - motor unit potential; 2 - muscle fiber potential (fibrillation potential); 3 - positive denervation potential; 4 and 5 - polyphase potentials (according to Buchtal); c - rhythmic discharges of two motor units.

Currently, many authors understand a motor unit as a set of functionally united muscle fibers working as a single whole. The almost simultaneous occurrence of excitation in the muscle fibers of the motor unit leads to potential oscillations that reflect the excitation of the motor unit as a whole (motor unit potentials). To study motor unit potentials, a concentric electrode is usually used (Fig. 2, 1). Bipolar electrodes (Fig. 2, 2) significantly distort the initial and end part motor unit potential.

With a “local” lead, the shape, duration and amplitude of the potential of an individual motor unit and the type of electromyogram are taken into account (Fig. 3). The shape of the motor unit potential is biphasic or triphasic with a predominantly pronounced negative phase; In approximately 3% of cases, polyphasic potentials occur. The duration of the potential of motor units depends on their structure. It tends to be greater in muscles with large motor units and less in muscles with small motor units. For example, in the quadriceps femoris muscle and the tibialis anterior muscle, where there are large motor units, including up to 1500-2000, and sometimes more muscle fibers, average duration The motor unit potential in adults is 10-15 ms, and in the eye muscles, the motor units of which have 5-10 muscle fibers, it is only 1-3 ms. The duration of the motor unit potential increases with age, for example, at the age of 10 years for the tibialis anterior muscle it is 9.7 ms, 30 years - 12.3 ms, 60 years - 15.2 ms. The amplitude of motor unit potential oscillations depends on the greater or lesser distance of the electrode from active muscle fibers and can reach 3-5 mV, but the average values ​​are much smaller - about 200 μV. In a relaxed muscle, biopotentials are not recorded. With weak muscle contraction, the motor unit potentials follow each other in the form of a non-strictly rhythmic series of oscillations of approximately equal amplitude. For the muscles of the limbs, the number of motor unit discharges per second is taken to be 5-10 with a weak contraction, 20-30 with an average contraction, and 50-60 with a strong contraction. The frequency of motor unit discharges in small muscles is usually higher than in large ones (in the muscles of the eye it reaches 150-200 per 1 sec).

An increase in the force of muscle contraction occurs both due to an increase in the frequency of repeated excitations of individual motor units, and due to the involvement of new motor units in the work. Accordingly, the type of “locally” assigned electromyogram changes. There are three main types: potentials of a single motor unit, mixed and interference. With a weak contraction, either the potentials of a single motor unit (type 1) or the potentials of many motor units are recorded, among which the potentials of a single motor unit (type 2) can usually be distinguished. With average strength and strong contractions, an interference electromyogram is recorded, in which it is almost impossible to isolate the potentials of individual motor units (type 3). Information about the synchrony of motor unit discharges is most accurately obtained using multielectrodes. According to the “local” lead, the degree of synchronization of motor unit discharges during weak muscle contractions in healthy people is insignificant; it persistently increases with some lesions of the spinal cord (see below electromyography in the clinic). Data from the “global” lead, which makes it possible to study the electromyogram during prolonged and maximum force muscle contractions, indicate a significant increase in healthy synchronization of motor unit discharges during fatigue and certain modes of muscle work.

The potentials of individual muscle fibers can only be recorded during muscle denervation, when the motor units cease to exist as a functional unit and individual muscle fibers begin to “spontaneously” excite. These are the so-called fibrillation potentials, which have a duration of 0.5 - 3 ms and an amplitude of 50-200 µV.

“Global” lead makes it possible to study fluctuations in electrical potentials that occur in a large volume of muscle tissue, usually containing hundreds of motor units. Typically, these potentials reflect the sum of the potentials of many motor units; therefore, the electromyogram with a “global” lead is often called total, although under some circumstances, with a “global” lead, the potentials of individual motor units can also be recorded. For “global” abduction, in addition to cutaneous electrodes, ordinary needles can be used; Under experimental conditions, implanted electrodes in the form of silver plates sutured to the muscle are used. In most cases, bipolar or unipolar leads with cutaneous electrodes are used. The unipolar abduction method justifies itself in sports physiology. In the clinic, bipolar leads are currently used almost exclusively. With it, the output electrodes are located at a distance of 1-2 cm from each other so that one is above the motor point, and the other is distal, or both are above the motor point. Typically, the discharge electrodes are permanently fixed to the insulating plate. In accordance with the needs of clinical electromyography, a special scheme for examining healthy subjects and patients was developed (Yu. S. Yusevich). This scheme provides mandatory registration biopotentials of symmetrical muscles at rest, i.e., during maximum voluntary muscle relaxation, during various tests leading to an involuntary change in muscle tension, and during voluntary contractions. In healthy subjects, in well-relaxed muscles, either no potential fluctuations are detected, or low-amplitude fluctuations are detected, which are considered by some authors to be a manifestation of muscle tone. During postural-tonic and voluntary muscle contractions, the electromyogram is represented by irregular oscillations of varying amplitude, shape and duration. With a weak contraction, more rare and uneven amplitude potential oscillations are recorded; with a strong contraction, the frequency and amplitude of the oscillations increase. The increase in oscillation amplitude with increasing static voltage is shown in Fig. 4. The frequency of vibrations can be different in different muscles, as well as in the same muscle groups in different subjects. On average, the frequency of oscillations with the maximum force of contraction is 100-150 per 1 sec. The amplitude of oscillations depends on many conditions: muscle development, their condition, the severity of the subcutaneous fat layer (especially in severe cases of obesity) and, to a large extent, on the choice of electrodes. The amplitude of oscillations at the maximum force of contraction can reach 4-6 mV. However, smaller values ​​are usually recorded (Fig. 5). The frequency of potential oscillations and the amplitude of oscillations change with changes in the synchronization of motor unit discharges. Increased synchronization during fatigue and certain modes of muscle work leads to a decrease in the frequency of oscillations and an increase in amplitude.

Rice. 4. Electromyogram of the biceps brachii muscle under static tension of varying strength (different load).

Rice. 5. Electromyograms recorded during maximum contraction of the right (upper curve) and left (lower curve) superficial flexor digitorum (bipolar abduction with cutaneous electrodes with an area of ​​0.5 cm 2 with a distance between the centers of the electrodes of 20 mm).

Large quantity Valuable information about the state of various parts of the motor system can be obtained by recording muscle biopotentials during electrical stimulation of nerve trunks and muscle fibers. Registration of an electromyogram during irritation of muscle fibers electric shock made it possible to determine, under normal and pathological conditions, the speed of propagation of excitation along muscle fibers, and with irritation of nerve trunks - the state of neuromuscular transmission, the speed of propagation of excitation along motor nerve fibers, and also to study mono- and polysynaptic reflexes.

In addition to the general visual assessment, mathematical processing of electromyograms is also used. The assessment of the total area of ​​the electromyogram per unit of time using integrators and machine processing for autocorrelation and especially cross-correlation analysis have become more widespread.