Electro neuromyography( ENMG) is a complex study that helps determine the overall functional state of the peripheral nervous system and muscles....
What is electroneuromyography and how is the examination carried out?
Electro neuromyography( ENMG) is a complex study that helps determine the overall functional state of the peripheral nervous system and muscles.
combines both methods of research described above, which gives a more complete picture:
- Electromyography( EMG) is a hardware method for studying the bioelectrical activity of muscles, by means of which the potential of the motor unit is determined at rest and during contraction. As you know, each muscle contains a different number of fibers, from 7 to 2,000, which depends on the type of muscle. Reducing synchronously, the muscle fibers form the potential of the motor unit, which is the sum of the potentials of the muscle fibers. The size and shape of potentials can vary with various diseases of the peripheral nervous system. By these changes, one can judge the state of the peripheral and central nervous system. The amplitude of the oscillations of the muscle potential is only a few millivolts, and the duration is not more than 25 ms. The electromyo
- Electroencephrine( ENG) The is a hardware method that allows you to measure the speed of an electrical impulse along the nerves. Muscles, like other executive organs, are connected with the central nervous system by the peripheral nerves. The signal is transmitted along the nerves to the spinal cord and brain, and the same happens in the opposite direction. During the study, the peripheral nerve is stimulated and the activity level is measured at two other points along the way.
Content of the article
- Content of the article
- What is the method of
- What is the
- method What is the use of ENDG
- Types of research
- Indications for diagnosis
- Contraindications for diagnostic
- Preparation for
- study How is diagnostics performed
- Decoding of results
- Where the
- What is the method of
study is conducted What is the essence of
The nervous system of our body consists of two parts that are functionally related to each other - the central nervous system and the peripheral.
The connection between them is carried out by means of electrical impulses transmitted along the nerves from the nerve endings to the brain and spinal cord. All our sensations are the information received from receptors and transferred to the brain.
In pathologies or diseases, the path of the impulse and the ability to correctly perceive information are disturbed.
For example, there may be a sensation of numbness, tingling, or chills on the skin. There are violations of pain sensitivity, as well as the work of the organs of sight, hearing and smell.
If the impulse path from the brain or spinal cord to the muscles is damaged or disturbed, the person either loses the ability to move, or can not do it fully. Manifestations of such diseases can be paralysis, muscle weakness, paresis.
During the study, a separate nerve is stimulated and the response of the corresponding muscle innervated by this nerve is recorded.
For example, in the study of the brain stimulate the auditory, optic nerves and analyze the response of the central nervous system.
Why is ENMG applied
ENMG is the most informative research method that helps diagnose diseases of the upper and lower extremities, joints and muscles.
This technique helps to identify the disease at an early stage, which greatly facilitates the cure of the patient.
No method of investigation can provide such complete information on the state of the axon. Electroneuromyography helps to determine in which part of the nerve the problem is and how serious it is.
Also, ENMG allows you to monitor changes in the patient's condition during treatment and the effectiveness of various therapies.
Types of research
Electroneuromyography of the upper and lower extremities can be carried out in three ways:
- Surface .Impulses are transmitted by means of cutaneous electrodes fixed on the upper and lower extremities. This is a non-invasive method without stimulation. The method is fairly simple and is widely used in medical examinations.
- Needle .Invasive method with the introduction of needle electrodes directly into the muscle and determining its activity.
- Stimulating .This type of electroneuromyography differs from superficial by stimulating the nerve fibers. The study is carried out using dermal and needle electrodes.
Indications for diagnosis
Electro neuromyography may be indicated in certain diseases:
- radiculitis-neuralgic disease resulting from injury or entrapment of the roots of the spinal nerves( cervical, thoracic, lumbar radiculitis);
- tunnel syndrome - pinching of the median nerve with the bones of the wrist and the tendons of the muscles;
- neuropathies - congenital or acquired nerve dysfunctions, the causes of which may be infectious diseases, injuries, diabetes mellitus;
- amyotrophic lateral sclerosis( BAS ) is an incurable lesion of the spinal cord and medulla oblongata;
- plexopathies - damage to the nerve plexus resulting from trauma, malignant tumor, radiation therapy, the result of which can be paralysis.
Along with these diseases, indications for ENMG may include symptoms such as:
- tingling or swelling of the lower limbs;
- pain and slow motion of the fingers;
- feeling of weakness and fatigue in the legs;
- ulcers on the skin;
- increased sensitivity of the upper and lower extremities to cold;
- asymmetry of movements;
- deformation of bones and joints.
Contraindications to the diagnosis
The procedure is contraindicated in patients with epilepsy and mental disorders, as well as hypertension.
In addition to these diseases, there are no significant risks, but before the test it is necessary to warn the doctor about the presence of a pacemaker, heart problems, pregnancy, infections and fear of the type of blood.
Preparing for the
study No special preparation is required for the study, but the result may be influenced by medications that affect the nervous system, coffee, strong tea, cola.
The medication should be stopped for 2-3 days, and toning beverages - 3 hours before the test.
How is the diagnosis of
Duration of the session - 30-60 minutes, depending on the type of ENMG and the size of the study.
The patient is on a recumbent or semi-reclining chair. Surface research is completely painless.
Minor pain may be present when the needle electrode is inserted during needle or stimulation ENMG.
The doctor determines the attachment points of the electrodes. These places are pre-wiped with a disinfectant solution and lubricated with a special gel. After the study, the patient may feel a slight weakness in the muscles.
Decoding of results
The interpretation of the results of ENMG can only be carried out by a qualified specialist.
He compares the received indications with the norm, determines the degree of deviation and on the basis of this data makes a diagnosis.
For example, with lesions of the peripheral nerve, the changes on the graph are clearly expressed: the rate of impulses is significantly reduced in both sensory and motor nerves.
The amplitude of the action potential of the nerve and the response of the innervated muscles in this case is reduced, stretched and has an altered shape.
In case of diffuse axonal damage, changes in speed are insignificant, but a decrease in the amplitude of the M-response of the muscle and the potential of the action of the nerve is well traced.
In tunnel syndromes and demyelination, the rate of excitation along the nerves varies.
Segmental lesions of the spinal cord or its anterior horns can be diagnosed by reducing the amplitude of the M-response, until its complete disappearance.
From the first person
Reviews of patients and doctors who use ENMG in their practice.
I have heard about this research for a long time, but decided on it only the other day. It was a little painful when the needles were inserted, but I courageously endured 20 minutes. The doctor gave a detailed transcript, with graphs and recommendations. Be sure to start treatment.
I thought that my joint hurts, but the doctor suspected neuropathy and appointed ENMG.The procedure was completely painless. Unfortunately, the diagnosis was confirmed.
I work as a neurologist for 17 years. I confess, there would be an opportunity, I would assign this study to every second patient. Electroneuromyography makes it easier and more accurate to diagnose the disease. It is possible to observe the dynamics and effectiveness of treatment.
Kirill Valerievich, neurologist
Where the research of
is conducted Electroneuromyography for today can be conducted in almost all major clinics in Russia.
The price of a study depends on the complexity of the case and the prices of the medical institution.
Typically, the cost ranges from 2 to 7 thousand.
The price of electroneuromyography of the lower extremities, for example, is almost two times cheaper than the examination of the facial nerve or neuromuscular transmission.