EEG of the brain is a non-invasive method of studying an organ in order to identify areas of increased convulsive readiness in its cortex. This diagnostic method allows you to determine in adults and children pathological changes, which are capable of influencing the functionality of individual areas of the hemisphere.

Electroencephalography (EEG) - research functional state brain by recording its bioelectrical activity. An electroencephalograph is used to carry out the procedure, followed by computer processing of the data.

The result of an EEG is an electroencephalogram - a graphic recording of brain rhythms in the form of curved lines.

What does it show?

This study shows:

• rhythms of electrical activity of the brain, their characteristics;
• the presence or absence of foci of increased convulsive readiness and their localization;
• consequences of brain surgery or stroke;
• tumor processes in the brain and their impact on functional activity;
• efficiency drug treatment for epilepsy.

Advantages

The main advantages of the EEG method in medicine:

• high accuracy and efficiency;
• no need for complex preparation;
• not only diagnoses diseases, but also helps to distinguish true disorders from simulations or hysteria;
• allows for research to be carried out when the patient is in serious condition or in a coma;
• is safe and painless for patients of different ages;
• the procedure is inexpensive, equipment is available in almost all hospitals;
• detects disturbances in brain function in the early stages, before the appearance of clinical symptoms.

Flaws

The study also has disadvantages:

1. High sensitivity of the device to movements and tremor caused by psycho-emotional stress patient, causes interference, which may complicate diagnosis.
2. You must remain calm and still throughout the entire examination.
3. Particular difficulties arise with children, since it is difficult for young patients to explain the importance of the procedure.

Main indications for use

An encephalogram is performed in the following cases:

• complaints of insomnia, problems falling asleep, waking up at night;
• frequent dizziness, fainting;
• severe causeless headaches;
• epileptic seizures;
• psychopathy, psychosis, nervous breakdowns;
• poisoning with neurotoxic substances (lead, mercury, manganese, pesticides, carbon monoxide and others);
• infectious and viral diseases affecting the brain (encephalitis, meningitis);
• suspicion of a tumor;
• comatose state of the patient;
• delay in speech or mental development in children;
• head and neck injuries;
• all types of strokes;
• diseases of the endocrine system;
• study of the sleep-wake cycle;
• before, after and during brain surgery.

Contraindications for EEG

There are no absolute contraindications for EEG of the brain, however, you can undergo the procedure on another day if you have:

• open head injuries;
• postoperative wounds;
• colds or ARVI, flu.

Caution should be exercised in studies in patients with acute mental disorders, as well as violent patients. Exercise tests (sounds, flashing lights), and even the very sight of a cap with electrodes can trigger an attack. If the benefit of the study exceeds possible risk, then EEG is performed in such patients with preliminary drug sedation in the presence of an anesthesiologist.

Types of research methods

Several EEG research methods are used:

• routine;
• with deprivation;
• long;
• night.

Depending on the duration and purpose, computer encephalography is divided into types:

1. Electroencephalogram of the brain - used in the initial stages of the examination. Both background activity and stress tests (hyperventilation, sharp sounds, flashes of light) are recorded.
2. EEG monitoring - long-term recording brain activity. It is used when it is necessary to cover all possible physiological states of the central nervous system (sleep, wakefulness, mental work, emotions).
3. Rheoencephalography is a study of cerebral vessels. Diagnostics is based on recording the changing value of electrical resistance of tissues when a weak current is passed through them high frequency. Provides information about the tone and elasticity of the vascular wall, the amount of pulse blood supply.

Routine method

The routine method consists of short-term (approximately 15 minutes) recording of brain biopotentials. This is necessary to examine and evaluate the dominant rhythms, the presence of pathological potentials and paroxysmal activity.

Functional tests are also carried out, during which the reaction to:

• opening - closing of eyes;
• clenching a fist;
• hyperventilation - forced breathing;
• photostimulation - blinking LEDs with eyes closed;
• sharp sounds.

The video shows an EEG with functional tests. Filmed by the channel “Clinic Doctor SAN”.

Encephalography with deprivation

Deprivation encephalography is performed with complete or partial sleep deprivation. Determines epileptic activity in situations that did not arise during provocative tests.

The patient either does not sleep all night or wakes up 2-3 hours earlier than usual. A routine EEG will be performed no earlier than 24 hours after the initial awakening.

Long-term EEG recording

Long-term recording of parameters during sleep is often performed after deprivation EEG, since sleep is a powerful activator for the detection of epiactivity.

Only when carrying out Sleep EEG can be carried out differential diagnosis epilepsy with cognitive impairment. Therefore, this type of examination is prescribed if the doctor suspects that changes in the brain occur while the patient is sleeping.

Night EEG

Night EEG recording occurs in a hospital setting as follows:

• begins a few hours before bedtime;
• covers the period of falling asleep and the entire night's sleep;
• ends after natural awakening.

If necessary, additionally:

• video monitoring;
• electrooculography (EOG);
• recording of a cardiogram (ECG);
• electromyograms (EMG);
• spirography.

How to prepare for research

Basic rules of preparation:

1. The day before, you need to thoroughly wash your hair with shampoo. Do not use styling products (varnishes, foams). Hair should be down.
2. Remove earrings, hairpins and all metal objects.
3. Before the examination, discuss with your doctor the use of medications (sleeping pills, tranquilizers, anticonvulsants, etc.). Some may need to be temporarily cancelled. If this is not possible, be sure to warn the specialist who will conduct the EEG so that he takes these circumstances into account when deciphering the results.
4. Give up alcohol, caffeine-containing and energy drinks (coffee, tea, Pepsi) 24 hours before. Do not consume chocolate and cocoa. The same applies to foods and medications with a sedative effect.
5. 2 hours before the procedure you need to eat, but not in excess.
6. It is advisable not to smoke on this day or at least 2-3 hours before the test.
7. Remain calm before and during the procedure. Avoid stress the day before.
8. Get a good night's sleep (except in deprivation studies).

Methodology

The EEG technique is as follows:

1. Electrodes are connected to the electroencephalograph, which are placed in the form of a cap on the surface of the subject’s head. The standard scheme provides for the installation of 21 electrodes. These sensors are designed to capture the potential difference between the electrodes in different leads and transmit information about them to the main equipment (device, computer) for automatic processing and analysis. They record at a certain frequency - 5–10 pulses per second.
2. The encephalograph processes the received signals, amplifies them and records them on paper in the form of a broken line, very reminiscent of an ECG. During recording, the patient is asked not to move and lie with eyes closed.
3. After a resting EEG, stress tests are performed to assess the brain's response to stress.
4. A neurologist or neurophysiologist must interpret the results and issue a conclusion.

The study is carried out in a specially equipped room, protected from noise and light.

How long does the procedure take?

The EEG time depends on the type of study:

Stages

Algorithm for conducting routine EEG:

1. The patient sits on a chair or lies on the couch, relaxes, and closes his eyes.
2. Electrodes are applied to the head. Places of contact with the skin are lubricated with gel or isotonic solution.
3. After turning on, the device begins to read information and transmit it to the monitor in the form of a graph. This records background activity.
4. Conducting functional tests necessary to assess the brain's response to stressful situations.
5. Completion of the procedure. The electrodes are removed, the doctor makes a description and prints out the results.

EEG monitoring

EEG monitoring is carried out to record and recognize brain activity during an epileptic attack.

The patient is hospitalized in a hospital for several days; for provocation, everything is canceled anticonvulsants. Monitoring is carried out with parallel audio and video recording for a day or more.

The method is more effective than conventional EEG for localizing areas of increased seizure activity, as well as for prescribing and monitoring the effectiveness of drug therapy.

Features of the procedure in children

For children under one year of age during sleep: the duration of the procedure is adjusted according to the regime.

Before the study:

• wash your hair with shampoo;
• fed;
• go to bed on schedule.

After a year, the child can be examined while awake. The parents’ task is to psychologically prepare the baby, talk about the procedure and its importance. You can come up with a game of astronauts or superheroes so that the child adapts faster.

EEG is performed for children without stress tests.

What do EEG results show and their interpretation?

The interpretation of the electroencephalogram shows many types of waves in one or more diagrams. Each of them has its own characteristics and will display a certain type of activity.

Decoding the EEG graph

The EEG can be deciphered based on the following parameters:

1. Alpha wave - will show the functioning of the brain in a state of inactive wakefulness. Depression of the α rhythm is caused by anxiety, fear, and activation of autonomic nervous activity.
2. Beta wave - wakefulness mode, active mental work. IN in good condition poorly expressed.
3. Theta wave - natural sleep and falling asleep. An increase in the theta rhythm is observed during prolonged psycho-emotional stress, mental disorders, twilight states characteristic of some neurological diseases, asthenic syndrome, concussion.
4. Delta wave - deep sleep phase. As in the case of the theta rhythm, its appearance during wakefulness indicates neurological disorders.

When describing the EEG, the following are taken into account:

• patient's age;
• general condition (tremor, visual impairment, weakness in the limbs);
• taking medications, anticonvulsant therapy;
• date of last attack;
• symmetry of rhythm amplitudes in different hemispheres;
• rhythm frequency;
• presence or absence of paroxysm;
• synchronicity of rhythms.

Coherence analysis is used to assess the synchrony of the functional activity of brain regions. One of its main advantages is its independence from the amplitude of oscillations of signals from different areas of the brain. This makes it possible to show and evaluate the participation of different areas of the cortex in the performance of certain brain functions.

To avoid collision with similar problems, it is necessary to carry out appropriate diagnosis in the presence of warning symptoms. High on the list of the most important procedures is electroencephalography, a fairly common type of brain research. Preparation for an EEG has a number of significant features that require special attention.

Brief introduction to EEG

This type of examination allows, through scanning, to track the activity of each part of the brain, neural impulses and, most importantly, the EEG clearly records the level of coordination of the actions of all components brain section(or the property of rhythmicity). If a person’s central nervous system is attacked by one or another ailment, diagnostics will reveal a disruption in the functioning of the organ.

Carrying out the test is not particularly difficult. The patient sits comfortably on an equipped couch in a reclining position. Certain points of the head are treated with a gel that ensures the conduction of impulses, and small electrodes are attached to the surface. When making a diagnosis, a person must relax his muscles and close his eyelids.

Next, a computer program is launched, which, using sensors, records brain activity and provides the necessary information in the form of several graphs. The procedure can last 1 hour, and in some cases the whole night under the close supervision of a doctor. The decrypted data will be received after a few days.

Despite the painlessness of EEG, a small child may become alarmed by what is happening, so the mother should be nearby and, if necessary, calm the child

Using EEG it is possible to detect:

• foci of epileptic activity;
• possible causes of fainting and panic attacks;
• various pathologies in the functioning of the brain and central nervous system as a whole;
• the effect of the prescribed complex of drugs on the body;
• violation of relevant functions, etc.

Indications and contraindications

It is worth noting quite wide range anomalies, upon detection of which the doctor, with a high degree of probability, will prescribe his patient a referral for an electroencephalogram of the brain:

• sleep disturbances, such as sleepwalking and insomnia;
• presence of mechanical injuries: bruises, fractures;
• vascular diseases of the brain;
• tumor-like formations;
• mental disorders, neurosis, nervous tics;
• chronic fainting, uncontrollable panic attacks;
• coma state.

• the need to confirm brain death;
• epileptic seizures;
• various seizures;
• stroke;
• disruption of the endocrine system;
• autism, Down syndrome, children cerebral palsy(cerebral palsy);
• encephalitis and meningitis;
• vegetative-vascular dystonia (VSD);
• chronic headache of various types;
• delay mental development or speech;
• disturbance of vascular circulation in the brain area, etc.

Special contraindications for at the moment not detected, but it is recommended to refrain from EEG for those who have various inflammations caused by infection, focal dermatosis, the presence open wounds and other injuries in the head area, the presence of surgically applied sutures that have not yet healed.

Traumatic head injuries are a contraindication to the procedure.

If the patient has pronounced neurological abnormalities in the form of a lack of control over the motor activity of his limbs, diagnosis should be carried out only under the close supervision of a qualified physician.

Procedure for preparing for an EEG

As mentioned earlier, before performing an encephalogram, attention should be paid to the features preparatory stage. There is a classic list of rules, the observance of which will lead to the most accurate result of brain research.

Sometimes the patient is prescribed an EEG during the dream phase. In this case, a prerequisite is the absence of sleep for hours. The body should not be “sleepy” at the time of direct testing of the brain.

Cost of EEG

If you go to a private medical center, you will most likely have to pay about rubles for the session. The cost of research in government institutions is significantly lower - rubles.

An electroencephalogram of the brain can detect pathologies of the central nervous system or, conversely, exclude them. Despite the relative simplicity of diagnosis, you should not neglect the set of basic rules for preparing for an EEG. Remember: only correct adherence to each point will ensure a good examination result and, as a result, will indicate a clear direction to the vector of treatment therapy.

Comments

You can do an EEG at any clinic for a psychiatrist or only where he will refer you

EEG can be done in any suitable hospital

How to cheat the EEG

I want to get a disability to spite the state, because I was called up by force (caught on the street) when I was studying at a university and now I have no diploma, no health (there are many other ailments), no compensation.

It is possible that you can somehow hide the watch battery in your mouth. The ECG definitely throws it off. But now before the test they put it in everyone’s mouth. How it affects the EEG - who knows, but it probably won’t be a plus.

Legal chemicals, suppressing nervous activity. Sleeping pills, for example. Perhaps the stimulants have some effect - eleotherak.

Electroencephalography

Electroencephalography (EEG) is a method for studying the functioning of the brain, based on recording electrical impulses emanating from its individual zones and regions. Such diagnostics have practically no contraindications; is fundamental for identifying epilepsy and some other brain pathologies. Electroencephalography (EEG) requires preliminary preparation. The result is deciphered jointly by the doctor conducting the study (neurophysiologist) and the neurologist treating the patient.

What is it

The brain consists of a huge number of neurons, each of which is a generator of its own electrical impulse. The impulses must be consistent within small areas of the brain; can strengthen or weaken each other. The strength and amplitude of these microcurrents are not stable, but must change.

This electrical (called bioelectrical) activity of the brain can be recorded using special metal electrodes placed on the intact scalp. They pick up brain vibrations, amplify them and record them as different vibrations. This is called electroencephalography, and for a person initiated into this “cipher” it is a graphical display of the brain’s work in real time.

Vibrations recorded on paper or displayed on a monitor are called waves. Depending on their shape, amplitude and frequency, experts divide them into alpha, beta, delta, theta, and mu waves.

Why do you need an EEG?

Diagnostics makes it possible to:

• assess the nature and degree of brain dysfunction;
• study the changes in sleep and wakefulness;
• determine the side and location of the pathological focus;
• clarify other types of diagnostics, for example, computed tomography when a person has symptoms of neurological diseases, and other research methods do not reveal any structural defect;
• monitor the effectiveness of medications;
• find the areas of the brain where epileptic seizures begin;
• assess how the brain works between periods of seizures;
• determine the causes of crises, panic attacks, fainting.

The injury itself or the site of development of the structural pathological process The EEG “does not see.” And if a person has had an attack of seizures or their equivalents, the study will be informative only a week or more after it.

Indications

Electroencephalography is widely used in the practice of neurologists. It not only helps to identify epilepsy, but when carried out with stimulation by light or sound, it allows one to distinguish a true visual or hearing disorder from a hysterical one, as well as from a simulation of such a condition.

EEG is indicated for:

• insomnia;
• sleep disorders (sleeping, sleep talking, sleep apnea);
• convulsive attacks;
• identified endocrine diseases;
• traumatic brain injuries;
• pathologies of the blood vessels of the head and neck (identified by ultrasound);
• encephalitis, meningitis;
• vegetative-vascular dystonia;
• after a stroke or mini-stroke;
• frequent headaches;
• dizziness;
• feeling of constant fatigue;
• after neurosurgery;
• more than one episode of fainting;
• panic attacks;
• diencephalic crises;
• any brain damage that developed before or after childbirth;
• stuttering;
• delayed speech development;
• autism;
• frequent awakenings during sleep.

Contraindications

There are no absolute contraindications for performing an EEG. If there are convulsive attacks, the person is sick with coronary heart disease, hypertension, or suffers from mental disorders, an anesthesiologist is present during the diagnosis (especially if functional tests are required).

Read also material about magnetic resonance imaging. What is it and what is it used for.

Preparation

It is not necessary to follow a specific diet, fast or cleanse the intestines before conducting an EEG, but the study is carried out after following several rules for preparing for it:

1. It is up to the doctor to decide whether or not to cancel the planned medication intake. You need to consult him about this in advance.
2. 12 hours before the examination, you need to stop taking products containing caffeine or energy drinks: coffee, chocolate, tea, cola, energy drinks.
3. Wash your hair, do not apply any products (spray, conditioners, masks, oils) to your hair after washing, as this will ensure insufficient contact of the electrodes with the scalp.
4. You need to eat a couple of hours before the procedure.
5. EEG is performed in calm state, that is, you can’t be nervous and worried when conducting research.
6. If the doctor needs to detect seizure activity in the brain, he may ask the patient to sleep for a short amount of time before the test. In this case, you cannot get to the medical facility while driving.
7. Do not undergo testing if you have ARVI.
8. Do not perform the examination with your hair on your head.

The study is not contraindicated for children and pregnant women, but during these periods it is performed without functional tests.

If an EEG needs to be performed on a child, then first:

• parents need to explain to him the essence of the procedure, that it will not hurt;
• practice putting on a cap (for a pool, a sports one), presenting it in the form of a game of pilots, tank crews, divers;
• practice breathing deeply;
• wash your hair, do not braid your hair, remove your earrings;
• before leaving the child, feed and calm him down;
• take with you delicious food and drinks, toys and books (to calm, distract from the procedure).

Progress of the procedure

This type of diagnosis is usually carried out during the day, but sometimes a sleep EEG is more informative.

The patient goes into a special room, isolated from light and sound; a special cap with electrodes is put on his head, he sits in a comfortable chair or lies down on a couch. Only he remains in the room; communication with doctors is maintained using a microphone and camera.

Several times the patient is asked to close and open his eyes to evaluate the artifacts that appear on the encephalogram during blinking. During the diagnostic procedure, the eyes remain closed.

If at any point during the procedure a person needs to change position or go to the toilet, he informs the researcher. Diagnostics is paused.

Various tests can be used to diagnose hidden epilepsy:

1. With a flash of bright light;
2. With monotonous light switching on and off;
3. With hyperventilation, for which the patient is asked to breathe deeply several times (against this background, he may feel dizzy, but this will stop as soon as he breathes as usual);
4. With a loud sound;
5. With falling asleep - independently or with the help of a sedative.

In all these cases, a seizure or its equivalent may develop.

The procedure lasts from 45 minutes to 2 hours during the daytime. After its completion, the person can return to their usual activities.

EEG price in Moscow

EEG is carried out both in public medical institutions and in private clinics.

In budgetary treatment and preventive institutions, the cost of conducting research is rubles. Private medical centers in Moscow, for example, "NIARMEDIC", "SM-Clinic", "Dobromed", " Mental health"and others offer this diagnostic for rubles.

The video describes the procedure:

How we save on supplements and vitamins: probiotics, vitamins intended for neurological diseases, etc. and we order on iHerb (use the link for a $5 discount). Delivery to Moscow is only 1-2 weeks. Many things are several times cheaper than buying them in a Russian store, and some goods, in principle, cannot be found in Russia.

Comments

After an encelography of my child’s brain, the conclusion said immaturity, I wanted to find out why this was happening and whether it would go away.

Electroencephalography of the brain: methodology

Electroencephalography (EEG) is a method of studying brain activity by recording electrical impulses emanating from different areas of the brain. This diagnostic method is carried out using special device, electroencephalograph, and is highly informative regarding many diseases of the central nervous system. You will learn about the principle of electroencephalography, indications and contraindications for its implementation, as well as the rules for preparing for the study and the methodology for conducting it in our article.

What is EEG

Everyone knows that our brain consists of millions of neurons, each of which is capable of independently generating nerve impulses and transmitting them to neighboring nerve cells. In fact, the electrical activity of the brain is very small, amounting to millionths of a volt. Therefore, to evaluate it, it is necessary to use an amplifier, which is what an electroencephalograph is.

Normally, impulses emanating from different departments brain are consistent within small areas of the brain; under different conditions they weaken or strengthen each other. Their amplitude and strength also vary depending on external conditions or the state of activity and health of the subject.

All these changes are quite capable of being registered by an electroencephalograph device, which consists of a certain number of electrodes connected to a computer. Electrodes installed on the patient's scalp pick up nerve impulses, transmit them to a computer, which, in turn, amplifies these signals and displays them on a monitor or on paper in the form of several curves, so-called waves. Each wave is a reflection of the functioning of a certain part of the brain and is designated by its first letter Latin name. Depending on the frequency, amplitude and shape of the vibrations, the curves are divided into α- (alpha), β- (beta), δ- (delta), θ- (theta) and μ- (mu) waves.

Electroencephalographs can be stationary (allowing research to be carried out exclusively in a specially equipped room) and portable (allowing diagnosis directly at the patient’s bedside). Electrodes, in turn, are divided into plate electrodes (they look like metal plates with a diameter of 0.5-1 cm) and needle electrodes.

Why do an EEG?

Electroencephalography registers some conditions and gives the specialist the opportunity to:

• detect and evaluate the nature of brain dysfunction;
• determine in which area of ​​the brain the pathological focus is located;
• detect epileptic activity in one or another part of the brain;
• assess brain function between seizures;
• find out the causes of fainting and panic attacks;
• carry out differential diagnosis between organic pathology brain and its functional disorders if the patient has symptoms characteristic of these conditions;
• evaluate the effectiveness of therapy in the case of a previously established diagnosis by comparing EEG before and during treatment;
• assess the dynamics of the rehabilitation process after a particular disease.

Indications and contraindications

Electroencephalography makes it possible to clarify many situations related to the diagnosis and differential diagnosis of neurological diseases, therefore this research method is widely used and positively assessed by neurologists.

So, EEG is prescribed for:

• disorders of falling asleep and sleep (insomnia, somnambulism, obstructive sleep apnea syndrome, frequent awakenings during sleep);
• seizures;
• traumatic brain injuries;
• neuro-circulatory dystonia;
• frequent headaches and dizziness;
• diseases of the lining of the brain: meningitis, encephalitis;
• acute cerebrovascular accidents;
• brain tumors;
• recovery after neurosurgical operations;
• fainting (more than 1 episode in history);
• panic attacks;
• constant feeling of fatigue;
• diencephalic crises;
• autism;
• delayed speech development;
• mental retardation;
• stuttering;
• tics in children;
• Down syndrome;
• suspected brain death.

There are no contraindications to electroencephalography as such. Diagnostics are limited by the presence of skin defects (open wounds) in the area where electrodes are supposed to be installed. traumatic injuries, recently applied, unhealed postoperative sutures, rashes, infectious processes.

The study should be carried out with caution in persons with mental illness, since they cannot always correctly follow the doctor’s instructions (in particular, to remain with their eyes closed and not move during the procedure), as well as violent patients, since they have both the device itself and A cap with electrodes can even cause a feeling of rage. If it is necessary to conduct an EEG in such patients, they are first administered sedatives, which at the same time distort the results of the study, that is, make it less informative.

Not every diagnostic department has a portable electroencephalograph in its arsenal, so in similar situation Patients with cardiovascular pathology in its later stages, as well as patients with limited mobility, may be a contraindication to the study. Transporting them to the diagnostic department may have more high risk rather than abandoning this research method when making a neurological diagnosis.

Do you need preparation for an EEG?

In order for the study to go smoothly and the result to be as informative as possible, the patient should follow several simple recommendations before the EEG.

• First of all, it is necessary to inform the attending physician about the medications that the patient is taking on an ongoing basis or in a course, but precisely during this period of time. Some of them (in particular, tranquilizers, anticonvulsants) can affect brain activity, thereby distorting the results, so the doctor will probably ask the patient to stop taking them 3-4 days before the test.
• On the eve of the study and on the day of it, do not eat foods that contain caffeine or energy substances - tea, coffee, chocolate, energy drinks and others. They will have an exciting effect on the patient’s nervous system, which will distort the EEG result.
• Before the procedure, wash your hair thoroughly, removing hair from any remaining styling foam, hairspray, etc. cosmetics. Do not use oils or hair masks, since the fat contained in them will worsen the contact of the electroencephalograph electrodes with the scalp.
• A few hours before the test, eat a full meal. Not eating will lead to hypoglycemia (low blood sugar), which will also affect the EEG.
• During the diagnostic process, you should not be nervous, but should be as calm as possible.
• If a patient is scheduled for a sleep EEG, the night before the test should be sleepless for him. Immediately before the EEG he receives sedative, which will help him fall asleep while recording the electroencephalogram. A sleep EEG is usually necessary for people with epilepsy.
• If the purpose of electroencephalography is to confirm brain death in a patient, the doctor should mentally prepare relatives for a possible disappointing result and, if necessary, involve a psychologist or psychotherapist to work with them.

The greatest difficulty is in performing electroencephalography on patients of childhood (especially early and preschool age). The baby is often frightened by the “hat” that a man in a white coat is trying to put on his head. In addition, it is very difficult to convince a child to keep his eyes closed during the examination and sit quietly - without moving. If the child is still undergoing an EEG, the doctor must explain to his parents what points to pay attention to when preparing (including psychological) their son or daughter for the study:

• convince the child that an absolutely safe and painless procedure awaits him, explain to him accessible language its essence;
• V game form practice putting on a swimming cap (you can present this as a game, for example, of divers);
• show your child by personal example how to breathe deeply, let him do it himself, agree with him to repeat the same thing in the doctor’s office when he or you ask;
• wash your hair well, do not do complex hairstyles (to quickly let your hair down), remove earrings, if any;
• fully feed before leaving;
• do not forget to take with you your favorite toy and book, as well as some goodies - food and drink; In case there is a wait before the EEG, the child can be distracted so that he does not think about the upcoming test or is not afraid of it.

Research methodology

Diagnostic time varies depending on the goals. More often it is carried out in the morning or afternoon, but in some cases it is necessary to determine the electrical activity of the brain directly during sleep.

The study is carried out in a specially equipped room, protected from noise and light. Only the patient and the doctor are present in the office, but in some clinics even the doctor is outside the office, maintaining contact with the patient through a video camera and microphone. When performing an EEG on a child, one of his parents must be present in the office.

The patient sits comfortably in a chair or lies down on a couch. A special “cap” is placed on his head: electrodes connected to each other by a network of wires. Research begins.

First, to assess the nature of artifacts (technical errors) from blinking, the doctor asks the subject to close and open his eyes several times. Considering this question complete, he asks the patient to close his eyes and sit/lie quietly without making any movements. The study is carried out for a short time, so it is usually not difficult for an adult patient to fulfill this diagnostic requirement. If the subject really needs to change his body position or, for example, wants to go to the toilet, the EEG recording is temporarily stopped. If, during the EEG recording, the patient nevertheless moved, or blinked, or made a swallowing movement, the doctor makes a corresponding note on the film or on the computer - these actions of the subject can affect the nature of the curve, and the doctor, if there is no note about them, may misinterpret them, which will affect the conclusion.

When the resting EEG is recorded, the patient is subjected to so-called stress tests to assess the brain's response to stressful situations:

• hyperventilation test: the specialist asks the subject to breathe deeply frequently for 3 minutes; such actions in a predisposed patient can provoke both an attack of generalized convulsions and an absence seizure;
• photostimulation: the test is carried out using a stroboscopic light source that flashes at a frequency of 20 times per second; thus, the brain's reaction to bright light is assessed; in predisposed individuals, myoclonic convulsions or an epileptic seizure occur in response to blinking.

The specialist who conducts the study must be prepared for the development of a pathological reaction of the patient’s body to provocative tests and have the ability and appropriate skills to provide him with emergency care.

At the end of the study, the patient should be reminded of the need to resume taking medications that were discontinued before the EEG.

Concluding the article, I would like to repeat that electroencephalography is a painless and highly informative method for diagnosing diseases of the central nervous system. It is indicated for many neurological conditions and, choosing between whether it is worth it or not, it is more correct to opt for the first: if there is no pathology, you will once again be convinced of this and will calm down, and if certain changes are detected on the EEG the correct diagnosis will be made faster, and you will begin to receive the correct treatment.

Clinic “Good Doctor”, clinic specialist Yulia Krupnova talks about electroencephalography:

How to pass the e-eg without finding anything

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An electroencephalogram allows you to establish an accurate diagnosis and the causes of brain dysfunction in just a few minutes. The primary source of the problems may be acquired or hereditary epilepsy, previous traumatic brain injury, excessive loads, stress and lack of sleep.

In such cases, the patient may experience frequent headaches and migraines, high or low blood pressure, compression of the temples, pain in the eyes, and attacks of varying severity. It is possible to establish an objective cause and understand whether the discomfort is associated with disorders of the brain using an EEG.

Rules for preparing for an electroencephalogram

Before you do an EEG of the brain, you need to properly prepare for the procedure. Only if you follow the rules described below can you count on receiving accurate data, and therefore a reliable diagnosis. In many ways, the interpretation of the obtained indicators depends on the knowledge and experience of the encephalographer. Real neurology specialists work at the Longevity clinic. You can rely on them and not worry about the results.

Preparation for the EEG includes:

• thorough washing of the hair on the eve of the procedure (the cleaner the patient’s head and hair are, the better the contact of the device with the brain will be, and the more reliable the data will be);
• regularity of taking medications prescribed by a doctor (if you stop taking medications or take a “break,” the brain can give a negative reaction and provoke an attack);
• a full breakfast/lunch (you cannot come to the procedure hungry, as this can again cause a strange reaction in the brain and distort the indicators);
• relaxation and tranquility (in EEG time It is important to relax, feel confident and calm, not be afraid of anything and try not to worry).
• During the procedure, various noises, pops, knocks, and sounds of different tones will be heard. There is no need to be afraid of this, since they are all aimed at identifying the response of the brain and analyzing reactions. Reading information during an attack or immediately after a cerebral hemorrhage or traumatic brain injury is considered especially important and useful.

On the website of the Longevity clinic you can find out more detailed information about electroencephalography, registration for it and consultation with a neurologist. After the research session, a specialist consultation is provided free of charge. EEG has no contraindications or side effects and does not cause pain or serious discomfort.

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One comment on “How to properly prepare for an EEG?”

1. Ilya December 4th,:08

How many days will it take to wait for EEG results?

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Electroencephalography (EEG): the essence of the examination, what it reveals, its conduct, results

For convenience long word Both doctors and patients replace “electroencephalography” with an abbreviation and simply call this diagnostic method EEG. It should be noted here that some (probably to enhance the significance of the study) talk about EEG of the brain, but this is not entirely correct, since the Latinized version of the ancient Greek word “encephalon” is translated into Russian as “brain” and in itself is already part medical term- encephalography.

Electroencephalography or EEG is a method of studying the brain (BM) in order to identify foci of increased convulsive readiness of its cortex, which is typical for epilepsy (the main task), tumors, conditions after a stroke, structural and metabolic encephalopathies, sleep disorders and other diseases. Encephalography is based on recording the electrical activity of the brain (frequency, amplitude), and this is done using attached different places surface of the electrode head.

What kind of research is an EEG?

Periodically occurring convulsive seizures, occurring in most cases with total loss consciousness, is popularly called epilepsy, which official medicine calls it epilepsy.

The very first and main method for diagnosing this disease, which has served humanity for many decades (the first EEG recorded dates back to 1928), is encephalography (electroencephalography). Of course, the research apparatus (encephalograph) has now significantly changed and improved, its capabilities with the use of computer technology have expanded significantly. However, the point diagnostic method remained the same.

Electrodes (sensors) are connected to the electroencephalograph, which are placed in the form of a cap on the surface of the subject’s head. These sensors are designed to capture the slightest electromagnetic bursts and transmit information about them to the main equipment (device, computer) for automatic processing and analysis. The encephalograph processes the received impulses, amplifies them and records them on paper in the form of a broken line, very reminiscent of an ECG.

Bioelectric activity of the brain is created mainly in the cortex with the participation of:

• The thalamus, which oversees and redistributes information;
• ARS (activating reticular system), the nuclei of which are distributed in various parts of the GM (oblongata and midbrain, pons, diencephalic system) receive signals from many pathways and transmit them to all parts of the cortex.

The electrodes read these signals and deliver them to the device, where recording occurs (graphic image - encephalogram). Information processing and analysis - tasks software a computer that “knows” the norms of biological activity of the brain and the formation of biorhythms depending on age and a certain situation.

For example, routine EEG detects the formation of pathological rhythms during an attack or in the period between attacks; sleep EEG or nighttime EEG monitoring shows how the biopotentials of the brain change while immersed in the world of dreams.

Thus, electroencephalography shows the bioelectrical activity of the brain and the consistency of the activity of brain structures during wakefulness or sleep and answers the questions:

1. Are there any foci of increased convulsive readiness of the brain, and if they are, in what area are they located?
2. What stage is the disease at, how far has it gone or, conversely, has it begun to regress;
3. What effect does the chosen medicine have and is its dose calculated correctly;

Of course, even the most “smart” machine will not replace a specialist (usually a neurologist or neurophysiologist), who receives the right to decipher an encephalogram after undergoing special training.

Features of EEG in children

What can we say about children, if some adults, having received a referral for an EEG, begin to ask what and how, because they doubt the safety of this procedure. Meanwhile, it actually cannot cause any harm to the child, but it can be really difficult to perform an EEG on a small patient. For babies under one year old, the bioelectrical activity of the brain is measured during sleep, before this they wash their hair, feed the baby and, without deviating from the usual schedule (sleep/wake), adjust the procedure to the child’s sleep.

But if for children under one year old it is enough to wait until they fall asleep, then a child from one to three years old (and some older) still needs to be persuaded, therefore, up to 3 years of age, the study is carried out in a state of wakefulness only for calm and sociable children, giving preference in other cases to EEG sleep.

Preparations for visiting the appropriate office should begin several days in advance, turning the future trip into a game. You can try to interest the baby in a pleasant trip, where he can go with his mother and his favorite toy, or come up with some other options (usually parents are more aware of how to convince the child to sit quietly, not move, cry or talk). Unfortunately, such restrictions are very difficult for young children to withstand, because they still cannot understand the seriousness of such an event. Well, in such cases the doctor is looking for an alternative...

Indications for conducting daytime encephalography in a child in a state of sleep or nighttime EEG are:

• Revealing paroxysmal conditions of various origins - epileptic seizures, convulsive syndrome due to high body temperature (febrile seizures), epileptiform seizures not associated with true epilepsy and differentiated from it;
• Monitoring the effectiveness of antiepileptic therapy with an established diagnosis of epilepsy;
• Diagnosis of hypoxic and ischemic lesions of the central nervous system (presence and severity);
• Determination of the severity of brain lesions for prognostic purposes;
• Study of the bioelectrical activity of the brain in young patients to study the stages of its maturation and the functional state of the central nervous system.

In addition, it is often suggested to do an EEG for vegetative-vascular dystonia with frequent fainting attacks and dizziness, with delayed acquisition of speech skills and stuttering. This method should not be neglected in other cases that require studying the reserves of the functional capabilities of the brain, because the procedure is both harmless and painless, but can provide maximum information for diagnosing a certain pathology. Electroencephalography is very useful if episodes of disturbances of consciousness occur, but their cause is not clear.

Different recording methods

Registration of bioelectric potentials of the brain is carried out in different ways, for example:

1. At the beginning diagnostic search to identify the causes of paroxysmal conditions, they use a short-term (≈ 15 min) routine method of recording an encephalogram, which, to identify hidden disorders, involves the use of provocative tests - the patient is asked to breathe deeply (hyperventilation), open and close his eyes, or is given light stimulation (photostimulation);
2. If a routine EEG does not provide the necessary information, then the doctor prescribes encephalography with deprivation (deprivation of sleep at night, completely or partially). To conduct such a study and obtain reliable results, the person is either not allowed to sleep at all, or is woken up 2-3 hours before the subject’s “biological alarm clock” rings;
3. Long-term recording of an EEG with registration of the bioelectrical activity of the brain cortex during “quiet hours” (sleep EEG) takes place if the doctor suspects that changes in the brain occur precisely while in “sleep mode”;
4. Experts consider night EEG to be the most informative, recording of which is carried out in a hospital setting. The study begins while you are awake (before going to bed), continues when you fall asleep, covers the entire period of night sleep and ends after natural awakening. If necessary, registration of bioelectrical activity of the brain is supplemented by the application of supernumerary electrodes and the use of video recording equipment.

Long-term recording of electrical activity over several hours during sleep and recording of nighttime EEG is called EEG monitoring. Naturally, such methods require the use of additional equipment and material resources, as well as the patient’s stay in a hospital setting.

Time and equipment make up the price

In other cases, there is a need to measure the biopotentials of the brain at the time of an attack. Pursuing similar goals, the patient, as for conducting an overnight EEG, is sent to a hospital for hospitalization, where 24-hour EEG monitoring is carried out using audio and video equipment. Continuous EEG monitoring with video recording throughout the day makes it possible to verify the epileptic origin of paroxysmal memory disorders, isolated auras, as well as episodic psychomotor phenomena.

Electroencephalography is one of the most available methods brain research. And for the price too. In Moscow, you can find this study for 1,500 rubles, 8,000 rubles (EEG sleep monitoring for 6 hours), and rubles (night EEG).

In other cities of Russia you can get by with a smaller amount, for example, in Bryansk the price starts from 1200 rubles, in Krasnoyarsk - from 1100 rubles, and in Astrakhan it starts from 800 rubles.

Of course, it is better to do an EEG in a specialized neurological clinic, where in doubtful cases there is the possibility of a collegial diagnosis (in such institutions, many specialists can encrypt the EEG), and also to consult a doctor immediately after the test or quickly resolve the issue regarding other methods of studying the brain.

About the main rhythms of electrical activity of the brain

When deciphering the results of the study, various factors are taken into account: the age of the subject, his general condition (the presence of tremor, weakness in the limbs, visual impairment, etc.), anticonvulsant therapy at the time of recording the bioelectric activity of the brain, the approximate time (date) of the last seizure and etc.

The electroencephalogram consists of various complex biorhythms emanating from the electrical activity of the brain at different periods of time, depending on specific situations.

When deciphering the EEG, first of all, pay attention to the main rhythms and their characteristics:

• Alpha rhythm (frequency ranges from 9 to 13 Hz, oscillation amplitude ranges from 5 to 100 μV), which is present in almost all individuals who have no complaints about their health during the period of inactive wakefulness (relaxation during rest, relaxation, shallow meditation). As soon as a person opens his eyes and tries to visually imagine any picture, α-waves decrease and may disappear altogether if the functional activity of the brain continues to increase. When deciphering the EEG, the following parameters of the α-rhythm are important: amplitude (μV) over the left and right hemispheres, dominant frequency (Hz), dominance of certain leads (frontal, parietal, occipital, etc.), interhemispheric asymmetry (%). Depression of the α-rhythm is caused by anxiety, fear, and activation of autonomic nervous activity;
• The beta rhythm (frequency ranges from 13 to 39 Hz, the amplitude of oscillations is up to 20 μV) is not only our wakefulness mode, the beta rhythm is characteristic of active mental work. In a normal state, the expression of β-waves is very weak, their excess indicates an immediate reaction of the brain to stress;
• Theta rhythm (frequency - from 4 to 8 Hz, amplitude is within microvolts). These waves reflect a non-pathological change in consciousness, for example, a person is dozing, half asleep, in the stage light sleep, he is already seeing some dreams, and that’s when θ-rhythms are discovered. In a healthy person, falling into sleep is accompanied by the appearance of a significant number of θ rhythms. An increase in the theta rhythm is observed during prolonged psycho-emotional stress, mental disorders, twilight states characteristic of some neurological diseases, asthenic syndrome, and concussion;
• The delta rhythm (frequency ranges from 0.3 to 4 Hz, amplitude from 20 to 200 μV) is characteristic of deep sleep (natural falling asleep and artificially created sleep - anesthesia). With various neurological pathologies, an increase in the δ wave is observed;

In addition, other electrical oscillations pass through the cerebral cortex: gamma rhythms, reaching high frequencies (up to 100 Hz), kappa rhythms, formed in the temporal leads during active mental activity, mu rhythms associated with mental stress. These waves are not particularly interesting from a diagnostic point of view, since they occur with significant mental stress and intense “thought work” that requires high concentration attention. An electroencephalogram, as is known, is recorded, although during wakefulness, but in a calm state, and in some cases, overnight EEG or sleep EEG monitoring is even prescribed.

Video: alpha and beta rhythms on EEG

EEG interpretation

main EEG leads and their designations

A bad or good EEG can be judged only after the final interpretation of the study results. Thus, we will talk about a good EEG if, during the waking period, the following were recorded on the encephalogram tape:

• In the occipital-parietal leads - sinusoidal α-waves with an oscillation frequency ranging from 8 to 12 Hz and an amplitude of 50 μV;
• In the frontal areas - β-rhythms with an oscillation frequency greater than 12 Hz and an amplitude not exceeding 20 μV. In some cases, β-waves alternate with θ-rhythms with a frequency of 4 to 7 Hz and this is also considered normal.

It should be noted that individual waves are not specific to any particular pathology. An example is epileptiform sharp waves, which under some circumstances can appear in healthy people who do not suffer from epilepsy. Conversely, peak-wave complexes (frequency 3 Hz) clearly indicate epilepsy with petit mal seizures, and sharp waves (frequency 1 Hz) indicate a progressive degenerative disease of the brain - Creutzfeldt-Jakob disease, therefore these waves are decoding is considered an important diagnostic feature.

In the period between attacks, epilepsy may not be noticed, since the peaks and sharp waves characteristic of this disease are not observed in all patients who show all the clinical symptoms of the pathology at the moment seizure. Moreover, paroxysmal manifestations in other cases can be recorded in absolutely healthy people who do not have any signs or prerequisites for the development of a convulsive syndrome.

In connection with the above, having carried out a single study and not finding epileptic activity on the background EEG (“good EEG”), it is impossible to completely exclude epilepsy based on the results of one test, if there are clinical signs diseases. It is necessary to further examine the patient for this unpleasant disease using other methods.

Recording an EEG during a seizure in a patient with epilepsy may provide the following options:

1. Frequent electrical discharges of high amplitude, which indicate that the peak of the attack has occurred, slowing down of activity - the attack has entered the attenuation phase;
2. Focal epiactivity (it indicates the location of the focus of convulsive readiness and the presence of partial seizures - we will have to look for the cause of the focal lesion of the brain);
3. Manifestations of diffuse changes (registration of paroxysmal discharges and peak-wave) - such indicators indicate that the attack is generalized.

If the origin of the brain lesion is established, and diffuse changes are recorded on the EEG, then the diagnostic value of this study, although not so significant, still makes it possible to find a particular disease that is far from epilepsy:

• Meningitis, encephalitis (especially caused by herpetic infection) - on EEG: periodic formation of epileptiform discharges;
• Metabolic encephalopathy - on the encephalogram: the presence of “triphasic” waves or diffuse slowdowns in rhythm and bursts of symmetrical slow activity in the frontal areas.

Diffuse changes in the encephalogram can be recorded in patients who have suffered a brain injury or concussion, which is understandable - with severe head injuries, the entire brain suffers. However, there is another option: diffuse changes are found in people who do not have any complaints and consider themselves absolutely healthy. It happens and if not clinical manifestations pathology, then there is no reason to worry either. Perhaps, at the next examination, the EEG recording will reflect complete normality.

In what cases does EEG help make a diagnosis?

Electroencephalography, revealing the functionality and reserves of the central nervous system, has become the standard for brain research; doctors consider its implementation advisable in many cases and for various conditions:

1. To assess the degree of functional immaturity of the brain in young patients (in a child under one year old, the study is always carried out during sleep, in older children - depending on the situation);
2. At various violations sleep (insomnia, drowsiness, frequent awakenings at night, etc.);
3. In the presence of convulsions and epileptic attacks;
4. To confirm or exclude complications of inflammatory processes caused by neuroinfection;
5. For vascular lesions of the brain;
6. After a TBI (brain contusion, concussion) - the EEG shows the depth of the GM’s suffering;
7. To assess the severity of the effects of exposure to neurotoxic poisons;
8. In case of development oncological process affecting the central nervous system;
9. For mental disorders various kinds;
10. EEG monitoring is carried out when assessing the effectiveness of anticonvulsant therapy and selecting optimal dosages of medications;
11. The reason to do an EEG may be signs of dysfunction of brain structures in children and suspicion of degenerative changes V nerve tissue GM in older people (dementia, Parkinson's disease, Alzheimer's disease);
12. Patients in a coma need to have their brain assessed;
13. In some cases, research is required surgical operations(determining the depth of anesthesia);
14. Encephalography will help to recognize how far neuropsychiatric disorders have gone in hepatic cellular failure (hepatic encephalopathy), as well as in other forms of metabolic encephalopathies (renal, hypoxic);
15. To all drivers (future and current) when passing medical examination To obtain/replace a license, they offer to undergo an EEG for a certificate provided by the traffic police. The survey is easy to use and easily identifies those who are completely unfit to drive. vehicles, therefore it was adopted;
16. Electroencephalography is prescribed to conscripts who have a history of convulsive syndrome (based on medical card data) or in case of complaints of attacks with loss of consciousness accompanied by convulsions;
17. In some cases, a study such as EEG is used to ascertain the death of a significant part of the nerve cells, that is, brain death (we are talking about situations when they say that “a person most likely turned into a plant”).

Video: EEG and detection of epilepsy

The study does not require special preparation

An EEG does not require any special preparation, but some patients are openly afraid of the upcoming procedure. It’s no joke - sensors with wires are placed on the head, which read “everything that is happening inside the skull” and transmit the full amount of information to the “smart” device (in fact, the electrodes record changes in the potential difference between two sensors in different leads). Adults are provided with symmetrical attachment to the surface of the head of 20 sensors + 1 unpaired one, which is superimposed on the parietal region; for a small child, 12 are enough.

Meanwhile, I would like to reassure particularly suspicious patients: the study is absolutely harmless, has no restrictions on frequency and age (at least several times a day and at any age - from the first days of life to old age, if circumstances so require).

The main preparation is to ensure hair is clean, for which the day before the patient washes his hair with shampoo, rinses and dries well, but does not use any chemicals for styling hair (gel, foam, varnish). Metal objects used for decoration (clips, earrings, hairpins, piercings) are also removed before an EEG is performed. Besides this:

• For 2 days, they give up alcohol (strong and weak), do not drink drinks that stimulate the nervous system, and do not indulge in chocolate;
• Before the study, obtain doctor's advice regarding medications taken. medicines(hypnotics, tranquilizers, anticonvulsants, etc.). It is possible that certain medications will have to be discontinued in consultation with the treating doctor, and if this cannot be done, then you should inform the doctor who will be involved in deciphering the encephalogram (a note on the referral form) so that he keeps these circumstances in mind and takes them into account when drawing up the conclusion.
• 2 hours before the examination, patients should not allow themselves a heavy meal and relaxation with a cigarette (such activities can distort the results);
• It is not recommended to do an EEG in the midst of an acute respiratory disease, as well as coughing and nasal congestion, even if these signs do not relate to an acute process.

When all the rules of the preparatory stage are followed, certain points are taken into account, the patient is seated in a comfortable chair, the places where the surface of the head comes into contact with the electrodes are lubricated with gel, sensors are attached, a cap is put on or dispensed with, the device is turned on - the recording begins... Provocative tests are used as needed during time of registration of bioelectrical activity of the brain. As a rule, this need arises when routine methods do not provide adequate information, that is, when epilepsy is suspected. Techniques that provoke epileptic activity ( deep breathing, opening and closing the eyes, sleep, light irritation, sleep deprivation), activate the electrical activity of the GM cortex, the electrodes capture the impulses sent by the cortex and transmit them to the main equipment for processing and recording.

In addition, if epilepsy is suspected (especially temporal epilepsy, which in most cases presents difficulties in diagnosis), special sensors are used: temporal, sphenoidal, nasopharyngeal. And, it should be noted, doctors have officially recognized that in many cases it is the nasopharyngeal abduction that detects the focus of epileptic activity in temporal region, while other leads do not react to it in any way and send normal impulses.

The abbreviation EEG stands for electroencephalography. This modern technique functional diagnostics, which is used to study the electrical activity of the brain. Today, this procedure is performed in most medical institutions.

Research principle

The brain contains more than 6 billion neurocytes. These are cells of the nervous system that have a body and many fibers (processes) connecting to each other (nerves consisting of motor axons and sensory dendrites). The functional activity of neurocytes is ensured by the production of nerve impulses in them, which represent electric current very little power. All processes in the brain - thinking, emotions, feelings - are ensured by the flow of electrical processes in neurocytes. Moreover, any somatic or infectious pathology leads to a change in electrical activity. Electroencephalography (EEG) is carried out using electrodes that are attached to the scalp in a certain order and record electrical potentials arising on the skin. Then, in a special diagnostic apparatus (electroencephalograph), these potentials are amplified and fed to recorders, which draw a curved line on a moving paper tape. The result obtained is called an electroencephalogram of the brain. Based on the changes in the resulting curve, a conclusion is made about the absence or presence of disturbances in the functioning of the brain, their nature and severity. Modern electroencephalographs digitize the received data and record it in a file. If necessary, the result can be printed, sent by email or saved in a medical database.

The first EEG was performed by the German psychiatrist Hans Berger in 1928. He also coined the term electroencephalography.

Types of EEG

Depending on the duration of the conduction and coverage of all physiological states of the brain (sleep, wakefulness, mental work, emotions), there are 2 types of EEG:

EEG monitoring is a more complex study and is usually used in a specialized neurological clinic.

The electroencephalography procedure itself is simple. It does not require special preparation (for better contact of the electrodes with the scalp, it must be clean). Mainly carried out in the morning outpatient setting or in medical hospital. Special sensors are attached to the head (a special elastic mesh with sensors arranged in a certain order is usually put on the head), one of them is attached to the earlobe (zero sensor). The process of taking an EEG lasts no more than 20 minutes. During the day, you can get the result of the study after the EEG has been deciphered by the doctor.

On the eve of the test, you should not take alcohol or medications for several days, as they can significantly affect brain activity and the test result.

Indications for use

An EEG of the brain is performed to determine its electrical activity in order to diagnose a number of diseases:

• Convulsive conditions, epilepsy - EEG allows you to determine the focus of pathological impulses, which leads to the development of attacks of tonic-clonic seizures.
• Malignant or benign neoplasms - in the area of ​​their development, electrical activity changes significantly.
• Various types of circulatory disorders, blood supply and blood outflow through venous vessels.
• Memory deterioration, impaired concentration, intelligence and mental performance - very often with the help of this study it is possible to differentiate somatic and mental diseases.
• Mental retardation - EEG of the brain in children will help determine the causes; it can be performed at any age.
• Open or closed injuries heads.
• Encephalitis or meningitis is an inflammatory process in the membranes and substance of the brain caused by viruses or bacteria.
• Neurotic conditions, neurasthenia (weakness of nervous activity) and emotional lability (sharp changes in mood).
• Chronic insomnia, jet lag with daytime drowsiness and inability to sleep at night.
• Frequent loss of consciousness and fainting.
• Headache unknown etiology.
• Age-related changes in the brain.
• Degenerative-dystrophic changes in the brain, in particular when a prion infection is suspected.
• Assessment of functional activity after stroke.

An electroencephalogram of the brain allows one to assess its functional activity and identify the location and cause of pathological changes.

Results

On the resulting electroencephalogram, a number of curve indicators are determined - frequency, amplitude, phase. On
Based on them, several rhythms of electrical activity are distinguished:

• Alpha rhythm - considered the main rhythm, it should prevail in both hemispheres. Its changes indicate a cerebral stroke, the development of dementia, the possible presence of an oncological process with a voluminous neoplasm, and neurosis.
• Beta rhythm - predominates to a greater extent over the frontal hemispheres. Changes in this rhythm indicate mental retardation, neurosis, encephalitis, or previous trauma.
• Delta and theta rhythms - normally they are recorded only in a sleeping person. Their appearance during wakefulness indicates possible dementia, the development of degenerative processes, and neoplasm.

EEG important method functional research, which is objective, informative and safe, so it can be performed on children, pregnant and lactating women.

2016-04-23 216 637

The human brain, without exaggeration, can be called the most complex and least studied human organ. The activity of brain tissue affects the functioning of human internal organs and systems. The work of neuron cells is accompanied by the release of electromagnetic impulses.

What is an encephalogram of the brain? instrumental research, which allows you to determine tissue activity and record the presence of any abnormalities.

The results of an EEG examination help to establish the presence of pathological changes that affect the functionality of individual areas of the hemispheres. EEG is the standard of research for suspected senile dementia, the development of epilepsy, mental illness and other abnormalities.

What is an EEG of the head?

Diagnosing the brain using EEG causes fear and even mistrust in most patients. This is mainly due to certain features of the procedure.

Special electrodes are attached to the person’s head and connected to a machine that reads the readings. From the outside, this picture looks unpleasant and even frightening. But this is where all the unpleasant aspects of the EEG end.

The research method is completely safe. By learning more about how the brain is examined using an encephalogram, you can overcome your fear of the procedure.

How the EEG device works, principle of operation

Already at the beginning of the nineteenth century, it was proven that the human brain emits electromagnetic impulses during work. At the same time, the first studies of the biological activity of neurons began.

The first experiments in conducting an encephalogram were made at the end of the 19th and beginning of the 20th century. The first photograph of a human EEG appeared in 1928. The advent of computer technology made it possible to increase the accuracy and information content of diagnostics. What is the working principle of this research method?

The EEG machine is connected to several electrodes, which read even small electromagnetic impulses and transmit information to an encephalograph connected to a computer. Using special software, signals are processed and analyzed automatically. The computer program prescribes the “norm” of brain activity, and the indicators vary depending on age and certain conditions.

Deciphering the encephalogram of the brain is carried out using coherent and spectral analysis. The first helps to see even minor deviations from the norm, the second to identify difficulties in the relationships between different parts of the hemispheres and the cerebral cortex.

Why is an EEG of the brain done?

An encephalogram of the brain is necessary if any disturbances in the functions and functioning of neuronal cells are suspected. There are several main indications for conducting this study.

The purpose of EEG diagnostics is:

• Assess the severity and depth of pathological disorders in the patient’s brain.
• Find out the location and localization of the affected area.
• Clarify data diagnostic studies, as well as determine the effectiveness of the prescribed treatment and make appropriate adjustments.
• To study the processes of activity of the nervous system, as well as to prevent convulsive conditions and epileptic attacks.
• An encephalogram of the brain is needed to determine the performance and vital activity of the brain in patients in a coma or under general anesthesia.

An encephalogram is prescribed to patients in the following cases:

An encephalogram of the brain shows the presence of mental complications and schizophrenia. Therefore, it is increasingly required to undergo an EEG before obtaining a license to drive a car or permission to carry or possess a firearm.

What does the EEG of the brain say?

The EEG shows exclusively pulsed electromagnetic activity of the brain. The encephalogram is carried out using a device that reads the strongest currents of the electromagnetic field, and also increases weak biocurrents as they pass through the device.

Interpretation of EEG results is carried out using a special computer program. The specialist compares the results with the norm. As a result, it is possible to determine the localization of disorders, as well as the degree of damage to various parts of the brain.

Is a brain encephalogram harmful?

Whatever they say on the Internet, there will be no harm from an encephalogram for a child or an adult, even if the study is repeated and repeated. During the examination, the drug only reads existing electromagnetic impulses, and does not create new ones; brain tissue is not exposed to radiological or any other radiation.

Complete encephalogram safe method. The only disadvantage of an EEG is the need to sit still for a while.

How to do an encephalogram of the brain

An indispensable condition for obtaining accurate diagnostic results using EEG is the complete immobility of the patient during the examination. The doctor performing the diagnostic procedure will prepare the person and talk about certain features of the encephalogram.

Preparing for an EEG of the brain

The encephalogram of the brain should look correct. To do this, several conditions must be met:

• Head immobility and absence of irritation factors during the entire procedure.
• The assessment of the level of brain activity using an encephalogram can be significantly distorted if, before the diagnosis, the patient takes sedatives or any other drugs that affect the functioning of the hemispheres.

To achieve these two goals, the doctor performing the examination conducts an interview with the patient, trying to set him up in a positive mood, explain how the procedure is carried out and why it is necessary.

Conducting an EEG on an adult

The procedure is carried out without any particular difficulties. The main task of the doctor is to create a positive attitude and reduce the patient’s possible fears before the procedure.

With the help of a high-quality device and provided the patient is immobile, even moderate changes in the bioelectrical activity of the brain are visible using EEG, indicating the onset of pathological changes or the presence of neoplasms. The procedure lasts only a few minutes.

Questions are answered by diagnosticians with extensive experience in conducting research.

EEG (Electroencephalogram) is a method that records its activity. It can be used to detect inflammation, epilepsy and tumors. The method makes it possible to carry out diagnostics in cases where the patient is unconscious. It does not cause harm to adults or children.

Thanks to metal electrodes that are placed on the head, the EEG records brain oscillations and shows them graphically. More accurate data are those taken before going to bed at night or during sleep.

In terms of time, an EEG of the brain lasts 60 minutes, but in problematic cases, eight-hour or daily activity monitoring is prescribed. The condition for accurate results is the patient's immobility during the examination.

At the moment, the electroencephalogram is the most accessible and frequently used research method in neurology and neurosurgery, which shows changes in the state of cellular activity of the brain.

The EEG result is presented in the form of a recording on a computer or on paper. Curves are recorded on paper and analyzed by a doctor. The rhythm of the waves and amplitude are assessed, the elements are identified and how they are distributed in space is recorded. Next, all the received data is combined and displayed in the conclusion, then it is pasted into the patient’s chart.

What does an EEG diagnose?

Thanks to the electroencephalogram, the dynamics of the disease and the reaction to the influence of medications taken by the patient are monitored. EEG makes it possible to observe changes, which is distinctive feature from basic diagnostic methods such as MRI and CT. This process painless, does not take much time and does not entail negative reactions.

EEG is an accurate and harmless research method.

The electroencephalogram is displayed as a curve as a result of recording fluctuations in electrical activity. As a result, the entire process of brain activity is observed.

A 24-hour EEG is not included in the mandatory examinations. Doctors prefer not to resort to modern technologies while they can manage using usual methods treatment. However, if the diagnosis is difficult to make, then they resort to an electroencephalogram study.

Indications for the procedure

If there is any suspicion of a deviation in the functions and functioning of neuron cells, an electroencephalogram is performed. It is prescribed to patients upon diagnosis:

• Concussion or trauma to the skull;
• After operations affecting the performance of the nervous system;
• When diagnosing neoplasms of cysts and tumors;
• For epilepsy;
• With manifestations of a neurological nature;
• Delayed speech or mental development in a child;
• Disease;
• If the patient is unable to explain the sensations (in childhood);
• Sleep disturbances.

The main goals of diagnosing an electroencephalogram are:

1. Assessment of the depth and severity of pathologies;
2. Identification of the site;
3. Assessing how effective current treatment is and adjusting it if necessary;
4. Study of active processes of the nervous system and prevention of epileptic attacks and convulsive conditions;
5. An encephalogram is needed to determine the vital activity and performance of a patient who is under or in a coma.

The duration is from 30 to 40 minutes, unless the doctor has prescribed a daily EEG. The duration of the examination depends on what disease needs to be diagnosed, but the examination is unlikely to take longer, even in serious cases.

Preparing for an EEG

To prepare for the procedure, stop taking three days before the examination. anticonvulsants. Do not use additional hair care products. Long hair dissolve, any decorations removed.

When preparing a child, he must be reassured and made clear that he will not be harmed or hurt.

EEG is not performed on people who have a cold or viral disease.

The examination is carried out while the child is sleeping, which makes it possible to accurately assess the baby’s condition and quickly detect pathological changes to prevent the development of serious consequences. To register the EEG, a special cap is put on the child’s head, and the doctor places electrodes under it. The scalp is pre-wetted with gel or water. Two inactive electrodes are applied to the ears, which are connected using clamps to the wires connected to the device. The current strength is small, which makes the examination a completely harmless procedure. Electroencephalogram is absolutely safe even for infants. A timely examination will detect the disease at an early stage. Indications for which an EEG of the child’s brain is performed:

• Injuries or bruises
• Monitoring the baby in the first year of life
• Migraine, fainting, dizziness
• Increased nervousness
• Insomnia

EEG diagnostics and conclusion

During the examination, the patient is in a room isolated from sound and light in a chair or on a couch. The doctor is in another room and communicates using a camera and microphone.

When using a good device and the patient being examined is immobile, an electroencephalogram reveals even minor changes in brain activity.

The final conclusion is made by a specialist, taking into account the symptoms that worry the patient.

Key aspects:

• Alpha rhythm. The norm is 8-14 Hz, the amplitude between the hemispheres is within 100 µV in a healthy person. A disturbance in the alpha rhythm indicates the presence of a tumor, cyst or heart attack. Instability and increased frequency indicate injury that may occur after a concussion. If the alpha rhythm is absent, then this indicates decreased mental activity;
• Beta Rhythm. Most often manifests itself in the frontal cerebral lobes in the two hemispheres with a symmetrical amplitude of 3-5 μV. Detects pathology with the following symptoms: asymmetry exceeds 50%, amplitude greater than 7 μV, sinusoidal beta rhythm, paroxysmal discharges;
• Theta and delta rhythm. Fixation occurs during sleep. The appearance of waves during wakefulness indicates existing dystrophic pathologies in the tissues;
• BEA (bioelectric activity). This aspect, in conclusion, is a holistic characteristic of brain rhythms. Synchronous activity without paroxysms is considered the norm. Changes are observed with depression.

Purpose

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