ENMG - what is it? This is the abbreviated name for the method of diagnostic examination of the nervous system of the body - electroneuromyography. An ENMG examination allows you to find out the condition of the muscles and peripheral nerves. To understand the principle of such diagnostics, let us briefly mention the structure of the human nervous system.
What processes can ENMG track?
What is the human nervous system? These are two huge, functionally and anatomically interconnected departments - central and peripheral. These are nerve roots, plexuses and nerves proper.
The latter are located in all tissues and organs of the body. Nerve pathways normally allow you to transmit various information from muscles, receptors and analyzers. Some diseases and injuries disrupt the path of the sensitive impulse - there is a feeling of crawling, numbness of the limb, problems with pain or temperature sensitivity. Some people have impaired vision or hearing due to damage to the peripheral nerves. In the most severe cases, the destruction of the connection between the motor nerve roots and muscles leads to paralysis and paresis. The reason for suchviolations allows you to track ENMG. Electroneuromyography examines the functional state of nerves and muscles using a special apparatus. With its help, artificial stimulation of the peripheral nerve is first performed. And then the electroneuromyograph registers the response of the muscle. When examining the state of the cerebral cortex, they act the other way around: they stimulate the auditory, visual and other zones with stimuli and register the response of the central nervous system.
ENMG - what is it and how does it happen?
Stimulation electromyography is otherwise called the study of conduction velocities (in foreign literature - NCS). During its implementation, a study of the H-reflex and F-wave is also performed. The diagnostic value of this procedure is high for neurotrauma, neuropathies and radiculopathies. A variety of ENMG can be called the study of the facial nerves and the blinking reflex. In case of facial injuries, it is very important to diagnose as early as possible - in the first two days. This will determine the prognosis of the disease, adjust the treatment. Repeatedly after 10 days, it is carried out if paralysis of the muscles of the face has developed.
Neuromuscular transmission study may be needed in myasthenic syndrome. This is a technique for studying the muscle potentials of fibers that are stimulated by impulses of different frequencies. Stimulation myography is not possible in the presence of electronic implants in the patient's body (for example, to correct the heart rhythm).
Needle ENMG
This type of research is invasive. A thin needle electrode is immersed in the muscle to studydenervation changes at the earliest stages. Muscle fibers are examined at rest and during functional tests. For the use of needle ENMG as a diagnostic method, certain indications are necessary: suspicion of a neuronal lesion. A neurologist with the help of it will be able to assess the features of the ongoing neural process. Also, the high information content of this method is noted in the study of myotonia. The structure of the motor unit (consisting of three levels - axonal, neuronal and muscular) changes as a result of pathological processes. A comprehensive analysis of the electrical activity of the muscle fiber will determine not only the type, but also the stage of compensatory changes. Allows you to diagnose the level at which the lesion occurred.
Surface (global) ENMG
The method is non-invasive. Muscle potentials are removed from the skin surface without violating its integrity - this is the reason for the better tolerance of this type of ENMG. What is it and what are its features? Much more muscles can be explored.
The method is recommended for suspected amyotrophic lateral sclerosis in the event that needle ENMG cannot be performed. This may be due, for example, to a low pain threshold, childhood, increased bleeding, transmissible infectious diseases. We have listed various diagnostic methods that have their own contraindications and can be performed on various nerves and muscles of the head and limbs. Before the study, the doctor will determine the goals andresearch objectives and assign the desired method. ENMG helps to make differential and topical diagnostics in myotonic syndromes, synaptic lesions, neuropathies of various nature (including toxic, inflammatory and metabolic), syringomyelia, polyradiculoneuritis. A study in dynamics will allow evaluating the effect of the prescribed therapy and predicting the further course of the pathological process.
