EEG of the Human Brain

Electroencephalography is a method of studying the brain based on the registration of the difference in electrical potentials arising in the process of brain activity.

The first in 1849 began to study the electrical processes of the brain D. Raymond, who proved that the brain has electrogenic properties, along with nerves and muscles. In 1913, VV Pravdich-Neminsky published the first electroencephalogram of the dog's brain, putting the very beginning of electroencephalographic studies there. But the first record EEG of the human brain appeared only in 1928, it was obtained by Hans Berger, an Austrian psychiatrist.

The EEG of the brain is recorded using electrodes located in certain areas of the head, taking into account the main parts of the brain. Provided from 16 to 24 (and more) amplifying-recording channels (blocks), which allow simultaneous recording of electrical activity, fixed by electrodes. The resulting record is called an electroencephalogram, and is an indicator of the total electrical activity of millions of neurons, which is mainly represented by the potentials of the bodies of nerve cells and dendrites. After the procedure, the EEG is deciphered.

Very often during the examination, a change in rhythms is recorded, which have their amplitude, reactivity, morphology and topography. There are the following frequency ranges of rhythms: delta rhythm (up to four Hertz), theta rhythm (four to eight Hertz), alpha rhythm (eight to thirteen Hertz) and beta rhythm (fourteen or more Hertz). The most physiological for a mature, calm, non-sleeping person is the alpha rhythm, which is determined when the eyelids are lowered over the posterior lobes of the brain. However, there are various types of physiological norms that take into account the nervous state and age of the patient. Throughout a person's life, the electroencephalogram is used to determine the various variations of the rhythm change.

Electroencephalography, or EEG of the brain, reflects the state of the cerebral cortex, subcortical brain structures, and the quality of the cortical-subcortical interaction, which allows to determine the presence of latent pathology, residual damage, and other undetected deviations. In addition, the EEG of the brain provides the necessary diagnostic information on the rate of maturation of the nervous system (for diagnosis in childhood), cerebral changes and brain lesions, pathological foci, epileptiform or epileptic activity. Also, this type of diagnosis allows you to track the course of the disease, adjust treatment and make any predictions.

A detailed EEG-conclusion helps to correctly diagnose the type of epileptic seizures, as well as in the differential diagnosis of other paroxysmal diseases, such as migraine, syncope, panic attacks and vegetative crises.

This examination is absolutely painless and harmless. During the examination, the patient sits with his eyes closed, relaxed, in a comfortable chair, i.e., in a state of passive wakefulness. In the case of an EEG, the child, he needs to be convinced of the painlessness of the survey and tell what exactly will happen. The patient at the time of the study should be fed, because the feeling of hunger can affect the results of EEG. The head should be thoroughly washed, which will make the contact of the electrodes with the scalp more qualitative. In addition, the results depend on the patient's age, medications taken, the presence of tremor of the head and limbs, skull defects and visual impairment. All these factors can influence the correct interpretation of EEG data and their further use.