Electroneuromyography: what is this decoding?
Electro-neurology is a diagnostic method for evaluating the state of the peripheral nervous system. This study is based on the graphical recording of bioelectric changes occurring in the nerve when a nerve impulse passes through it and in a muscle when it is contracted in response to this impulse.The essence of the method What information is provided by the electroneurography Indications Contraindications Preparation Carrying out the study Electroencephalography: deciphering the results
The essence of the
method The human central nervous system( CNS) is connected to the muscles by the peripheral nerves.Each nerve consists of sensitive and motor fibers: the sensory ones transmit signals from the receptors to the brain, and the motor nerves from the CNS structures to the muscles. If you apply sensors to the nerve region and the innervated muscle, give them an electrical signal through them and record everything that happens, you can see at what speed and how well the nerve impulses pass. This is the essence of electroneurography.
What information is provided by the
electroneurography Electroenography is used to detect the pathology of the peripheral nerves.With , the doctor can determine the level and nature of the lesion using this diagnostic method. That is, in which part of the nerve the failure occurs, which fibers are damaged, in what condition is the axon and myelin sheath.
Important: The can not be diagnosed accurately by an electroneurograph alone.This study helps to know just what changes in the functioning of the neuromuscular system occurred, but the causes, mechanisms of the disease and the disease itself are determined solely from the totality of the data obtained during the comprehensive examination of the patient.
Electroenography is indicated for the following diseases( or suspected of them):
- Neuropathy( including diabetic, traumatic, toxic);
- myasthenia gravis;
- muscular dystrophy;
- demyelinating pathologies( conditions accompanied by destruction of the myelin sheath of nerve fibers);
- tunnel syndrome( develops due to compression of the large nerve of the hand);
- ailments of the spine, characterized by radicular syndrome( congestion and inflammation of the spinal roots);
- with amyotrophic lateral sclerosis;Injuries of the nerve trunk.
To make the study qualitative, electroneurography is supplemented with electromyography. Electromyography is a method for diagnosing electrical muscle activity.
It is undesirable to perform electroneurography for patients suffering from epilepsy, severe angina, hypertension, and psychiatric disorders .An obstacle to performing electroneurography is also the presence of a pacemaker in the human body.In addition, do not apply electrodes to the damaged and inflamed skin.
Several days before the study, it is necessary to stop taking medications that affect the neuromuscular apparatus( muscle relaxants, anticholinergics, tranquilizers, etc.).These drugs may distort the result of the study.
Directly on the day of the procedure, it is recommended not to smoke, not to drink alcohol and caffeinated drinks( including strong tea).
Study Electro-neurology is not a difficult study. In some patients, it can cause discomfort - it all depends on the pain sensitivity and on what areas are examined.
At the beginning of the procedure, the doctor applies two electrodes( metal discs) on the patient's body: the first one - in the projection of the nerve, the second - on the muscle innervated by this nerve.An electric signal is applied to the electrode applied to the nerve, and the second electrode fixes this signal on the muscle( the muscle contracts) and transfers it to the apparatus, which translates the obtained information into a graphic image.The main parameter, determined in the course of electroneurography, is the rate at which the impulse passes through the nerve fiber.In addition, physicians are interested in the characteristics of the wave-like graphic representation of the muscle response( amplitude, shape, duration).
To better assess the functional state of the nerve, various electrical stimulation options( rhythmic, nonrhythmic, etc.) can be used.
The study is necessarily conducted alternately on both sides of the body( for example, first on one arm, then on the other). At the end of the procedure, the obtained data is compared.
Electro neurography: interpretation of the results
The conclusion is based on the results of the study by the doctor-diagnostician, and the final diagnosis is made by a neurologist who directed the electroneurography. This is what you need to contact.
I would like to note once again that electroneurography does not provide an opportunity to identify a specific disease, but helps only to diagnose the impairment: a decrease in the speed of the pulse, a change in the amplitude of the muscle response or its complete absence, etc.Based on this information the neuropathologist makes his clinical conclusion, then assesses the results of other studies, diagnoses and prescribes treatment.
Zubkova Olga Sergeevna, medical reviewer, epidemiologist doctor