ENMG - what is it? So abbreviated as the method of diagnostic research of the nervous system of the body - electroneuromyography. An ENMG examination allows you to find out the state of the muscles and peripheral nerves. To understand the principle of such a diagnosis, we briefly mention the structure of the departments of the human nervous system.
What processes does ENMG track?
What is the human nervous system? These are two huge, interconnected functionally and anatomically, departments - central and peripheral. These are nerve roots, plexuses and actually nerves.
The latter are located in all tissues and organs of the body. Nerve pathways normally allow the transmission of various information from muscles, receptors and analyzers. Some diseases and injuries violate the path of the sensitive impulse - there is a feeling of creeping goosebumps, numbness of the limb, problems with pain or temperature sensitivity. Some people have impaired vision or hearing due to damage to their 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 cause of such violations 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 records the muscle response. When researching the state of the cerebral cortex, they act the other way around: they stimulate the auditory, visual and other zones with stimuli and record the central nervous system response.
ENMG - what is it and what does it happen?
Stimulation electromyography is also called a study of the rates of conduction (in foreign literature - NCS). During its conduct, an investigation of the H-reflex and the F-wave is also performed. High diagnostic value of this procedure for neurotrauma, neuropathies and radiculopathies. A kind of ENMG can be called a 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 treatment. After 10 days, it is repeated if paralysis of the muscles of the face has developed .
A study of neuromuscular transmission may be needed for myasthenic syndrome. This is a technique for studying the muscle potentials of fibers that are stimulated by pulses of different frequencies. Stimulation myography is not possible if there are electronic implants in the patient's body (for example, to correct heart rhythm).
Needle ENMG
This type of study is invasive. A thin needle electrode is immersed in the muscle to study denervation changes in 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 needed: suspected neuronal damage. A neurologist with his help will be able to assess the features of the ongoing neural process. Also, 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 muscle) changes as a result of pathological processes. A comprehensive analysis of the electrical activity of 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.
Superficial (global) ENMG
The method is non-invasive. Muscle potentials are removed from the surface of the skin without violating its integrity - this is associated with better tolerance of this type of ENMG. What is it and what are its features? Much more muscle can be explored.
The method is recommended in cases of suspected amyotrophic lateral sclerosis if it is impossible to conduct needle ENMG. This may be due, for example, to a low
pain threshold, childhood, increased bleeding, and vector-borne infectious diseases. We have listed various diagnostic methods that have their contraindications and can be performed on various nerves and
muscles of the head and limbs. Before the study, the doctor will determine the goals and objectives of the study and prescribe the desired method. ENMG helps to make differential and topical diagnostics in case of myotonic syndromes, synaptic lesions, neuropathies of various kinds (including toxic, inflammatory and metabolic), syringomyelia, polyradiculoneuritis. A study in dynamics will allow to evaluate the effect of the prescribed therapy and predict the further course of the pathological process.