Electroencephalography (EEG) in children - features of the examination of the brain. What does the EEG show in childhood: diagnostic criteria for various diseases Detects the EEG of the brain of children

Causeless headaches, poor sleep, fatigue, irritability - all this can be the result of poor blood circulation in the brain or abnormalities in the nervous system. For the timely diagnosis of negative disorders in the vessels, an EEG is used - an electroencephalogram of the brain. This is the most informative and accessible examination method that does not harm the patient and can be safely used in childhood.

An electroencephalogram is used to examine the blood vessels of the brain.

EEG of the brain - what is it?

An encephalogram of the head is a study of a vital organ by exposing its cells to electrical impulses.

The method determines the bioelectrical activity of the brain, is very informative and most accurate, as it shows the complete clinical picture:

• the level and spread of inflammatory processes;
• the presence of pathological changes in the vessels;
• early signs of epilepsy;
• tumor processes;
• the degree of impaired brain functioning due to pathologies of the nervous system;
• consequences of a stroke or surgery.

EEG helps detect signs of epilepsy

The EEG helps monitor changes in the brain, both structural and reversible. This allows you to monitor the activity of a vital organ during therapy, and adjust the treatment of identified diseases.

Where can I do and the price of the survey

Electroencephalography can be done at any specialized medical center. Institutions can be either public or private. Depending on the form of ownership, the level of qualification of the clinic, as well as the equipment used, the prices for the procedure differ significantly.

In addition, the following factors influence the cost of an encephalogram:

• the duration of the diagnostic procedure;
• carrying out functional tests;
• the use of special programs (for mapping, studying epileptic impulses, comparing zones of symmetrical zones of the brain).

Indications for an electroencephalogram

Before prescribing encephalography to a patient, a specialist examines a person and analyzes his complaints.

The following conditions may be the reason for the EEG:

• sleep problems - insomnia, frequent awakenings, sleepwalking;
• regular dizziness, fainting;
• fatigue and constant feeling of fatigue;
• causeless headaches.

Do not eat chocolate the day before the test.

How is an electroencephalogram performed?

Assessment of the electrical activity of brain cells is carried out using an encephalograph. It consists of sensors (electrodes) that resemble a cap for a pool, a block and a monitor to which the monitoring results are transmitted. The study is conducted in a small room that is isolated from light and sound.

The EEG method takes a little time and includes several steps:

1. Training. The patient takes a comfortable position - sits on a chair or lie down on the couch. Then the electrodes are applied. A specialist puts on a “hat” with sensors on the head of a person, the wiring of which is connected to the device, which captures the bioelectric impulses of the brain.
2. Study. After turning on the encephalograph, the device begins to read information, transferring it to the monitor in the form of a graph. At this time, the power of electric fields and its distribution by different parts of the brain can be recorded.
3. Use of functional tests. This is the implementation of simple exercises - blinking, looking at light flashes, breathing rarely or deeply, listening to sharp sounds.
4. Completion of the procedure. The specialist removes the electrodes and prints the results.

During the EEG, the patient take a comfortable position and relax

If the study requires a deeper study (daily monitoring), there may be breaks in the procedure. The sensors are disconnected from the wires, and the patient can go to the toilet, have a snack, chat with relatives.

Features of the EEG in children

Monitoring brain activity in children has its own nuances. If the child is under one year old, then the study is carried out in a state of sleep. For this, the baby should be fed and then rocked. After a year, children are examined in a waking state.

For the procedure to be successful, it is important to prepare the child:

1. On the eve of the examination, it is recommended to talk with the child about the upcoming procedure. You can come up with a game so that the baby adapts faster by calling him a superhero or an astronaut.
2. Take your favorite toys with you. This will help distract the fidget and calm him down at the right time.
3. Feed the child before the start of the study.
4. Discuss with the doctor the time of manipulation and choose a convenient time when the child is awake and does not feel sleepy.
5. On the eve of the examination, wash the baby's head well. If this is a girl, undo the hair, remove all jewelry (immediately before the monitoring).

How long does the procedure take

A normal encephalogram is a routine EEG or diagnosis of a paroxysmal condition. The duration of this method depends on the area under study and the use of functional samples in monitoring. On average, the procedure does not take more than 20-30 minutes.

During this time, the specialist manages to carry out:

• rhythmic photostimulation of different frequencies;
• hyperventilation (breaths are deep and rare);
• load in the form of slow blinking (open and close eyes at the right time);
• detect a number of functional changes of a latent nature.

In case of insufficiency of the received information, specialists can resort to a deeper examination.

There are several options:

1. Encephalogram of nocturnal sleep. A long period is being studied - wakefulness before bedtime, nap, going to bed and morning awakening.
2. EEG with deprivation. The method consists in the fact that the patient is deprived of a night's sleep. He should wake up 2-3 hours earlier than usual and stay awake the next night.
3. Continuous electroencephalogram. Monitoring of the bioelectrical activity of the brain occurs during daytime sleep. The method is very effective in case of suspected paroxysm (seizure) or identifying the causes of sleep disorders.

Based on the EEG method, the duration of such a study can vary from 20 minutes to 8-15 hours.

Deciphering EEG indicators

The interpretation of the results of the encephalogram is carried out by a qualified diagnostician.

When decoding, the patient's clinical symptoms and the main EEG indicators are taken into account:

• state of rhythms;
• symmetry of the hemispheres;
• changes in gray matter when using functional tests.

The results obtained are compared with the established norms, and deviations (dysrhythmia) are recorded in the conclusion.

Table "EEG decoding"

Based on the study of rhythms, a conclusion is made about the bioelectrical activity of the brain. In a normal state, it should be without seizures (paroxysms), have regular rhythm and synchrony. Diffuse (moderate) changes are acceptable if no other pathological disorders are detected (irritation of parts of the brain, dysfunction of regulatory systems, disorganization of rhythms). In this case, the specialist can prescribe corrective treatment and monitor patients.

It is important to take into account that moderate changes in rhythms (delta and theta), the appearance of paroxysmal discharges and epileptic activity on the EEG in children and people under 21 years of age are the norm and do not apply to abnormalities in the structures of a vital organ.

Validity of electroencephalography

The results of the encephalogram are valid for 1 to 6 months.

Deadlines may vary depending on:

• diseases;
• therapy (repeated EEG is needed when adjusting treatment or evaluating the effectiveness of prescribed drugs);
• informative value of the selected EEG method.

If a person is healthy or the electroencephalogram has slight changes, the conclusion is valid for six months. In case of serious deviations or the need for regular monitoring of brain activity (especially in children), the EEG period may be a month or a week.

The use of electroencephalography to assess the state of brain activity makes it possible to identify a number of pathologies in the early stages. The EEG method makes it possible to determine developmental delay in children even before the first manifestations. In addition, the procedure is completely harmless, it can be done an unlimited number of times, even in early childhood. The encephalogram is used not only to detect abnormalities, but also as a tool to monitor the effectiveness of treatment.

Any examinations concerning the determination of the state of the brain in children cause a storm of emotions in their parents. In fact, most diagnostic methods used in pediatrics are absolutely painless and safe. One of them is this.

The essence of the method

The EEG of the brain in children is a type of activity study, which is based on the fixation of electrical potentials. This method is considered the best way to obtain information about the work of the brain in babies at any age. The human nervous system is made up of billions of cells called neurons. All of them have the ability to create and transmit electrical impulses. The general activity of neurons forms the bioelectrical activity of the brain. It is she who is recorded and recorded graphically in the EEG. The result is an electroencephalogram. This document with a lot of curved lines informs the doctor about how the processes in the child's brain proceed: in normal mode or whether they have undergone pathological changes.

Indications for the procedure

Having received from the doctor a referral for encephalography and having learned the answer to the question: “What is this - an EEG of the brain?”, Mom and dad, naturally, begin to think with fear about why their child needs this procedure. At the same time, it is recommended not only if you suspect the presence of a particular disease, but also for a standard assessment of the baby's brain function. Encephalography for a child can be prescribed by a psychiatrist, neurologist or neurophysiologist. The standard indications for the procedure are as follows:

• convulsions and seizures of cerebral origin;
• brain injury;
• tumors and other diseases of the brain;
• assessment of the adequacy of the development of children in the first year of life;
• frequent headaches, dizziness, loss of consciousness;
• sleep disturbance, including sleepwalking;
• irritability, irascibility;
• unexplained regular crying;
• unstable blood pressure.

As you can see, this study is prescribed for so many problems associated with the functioning of the nervous system. And all because the EEG of the brain reveals the main violations in its functioning. Encephalography allows not only to diagnose diseases such as cerebral palsy, minimal cerebral dysfunction, encephalopathy, autonomic dystonia syndrome, epilepsy, and others, but also to select drugs for their treatment, as well as to evaluate the effectiveness of therapy.

In addition, even if the baby does not have serious diseases, but there are difficulties in behavior and development, an EEG is shown to him. This procedure can help the doctor determine the causes and severity of pathologies in case of lag in speech and motor development, problems with memory and attention, hyperactivity, and so on. EEG is also recommended for school-age children if they are too tired or overexerted.

Child preparation

Before you do an EEG of the brain, the baby must be prepared. Since the encephalography procedure involves the installation of electrical sensors on the child's head, it is recommended to wash his hair with baby shampoo the day before the examination. Further features of the preparation depend on the age of the child.

Babies do EEG only in a state of sleep, as a rule, this occurs during the day. In order for the baby to fall asleep for sure, when scheduling the procedure, it is advisable to take into account his usual schedule of sleep and wakefulness. Also, doctors advise to feed the baby immediately before the session from the bottle. If he is breastfed, then the mother should express milk.

For children after a year, encephalography is performed during wakefulness. At the same time, it is very important that the child behaves calmly and clearly follows the instructions of the doctor. It is especially difficult to realize this condition with two-three-year-old fidgets. So, parents should pay special attention to the psychological preparation of their son or daughter. Here is what psychologists recommend:

• Firstly, it is worth talking with the child, describing the future examination as a fun and safe game. For example, you can say that he will become an astronaut or a superhero.
• Secondly, it is best to take toys and books with you to the clinic that can distract and calm the baby. It can be well-known and favorite pastimes or, conversely, new and exciting ones.
• Thirdly, so that the baby does not act up, it must be fed shortly before the EEG. In addition, you should try to plan the daily routine so that at the time of the session the child does not want to sleep yet.
• Fourthly, in some cases, during the procedure, the crumbs are required to perform certain actions (opening their eyes, breathing at a given pace, passing tests).

All this makes sense to rehearse at home in a relaxed atmosphere. In addition, since the child will need to wear a special hat, it is advisable to include this moment in the preparation process. It is worth noting that if the child regularly takes any medications, then it is impossible to refuse them before the EEG. You just need to tell your doctor about it. Encephalography has no contraindications, but this procedure is not performed if the child has a runny nose and cough. Before the session, all jewelry, including earrings, must be removed from the baby’s head, as well as loose hair.

Start of the procedure

Encephalography is carried out in a small light and soundproof room equipped with a couch or changing table, as well as a recording device. Before the procedure, a special cap is put on the child's head. It can look like a fabric helmet with electrodes or a rubber mesh, on which the required number of sensors is pinned in manual mode. Sensor-electrodes are connected to the encephalograph using soft wires. It should be noted that the biocurrents flowing in the electrodes are very small and cannot harm the baby.

In addition, encephalographic equipment must be grounded. Before applying the sensors, the doctor wets them with gel, water or saline. This is done to avoid the formation of an air cushion between the scalp and the electrode. Sometimes it is required to wipe the skin itself with alcohol to remove sebum from it. In addition, clip-electrodes are put on the baby's ears, which do not conduct current.

Features of the study

The order in which the brain EEG is done is determined by the age of the child. Babies under one year old most often lie in their mother's arms or on a changing table. It is important that the baby sleeps during the procedure. If the baby is naughty, then the doctor must first calm him down. An encephalography session lasts up to 20 minutes. Its purpose is to register the bioelectrical activity of the baby's brain in a calm state. Older kids may have more complex tests. The child is placed on the couch in a reclining position, while the head should not be tilted forward, otherwise distortions in the electroencephalogram may occur. It is also necessary that the little patient be completely relaxed. The standard EEG procedure includes the following steps:

1. Recording the "background curve", that is, fixing the activity of the brain at rest.
2. Eye opening-closing test. It allows you to study the work of the brain during the transition from rest to activity and vice versa. At this stage, the child should open and close his eyes at a certain interval at the command of the doctor.
3. Hyperventilation test. Thanks to this exercise, you can identify pathologies such as latent epilepsy, inflammation and brain tumors, chronic stress, and so on. Hyperventilation involves rare, but deep breaths and exhalations, usually the doctor turns this process into a game, offering the baby to “blow hot” or “put out the candle”.
4. Photostimulation test. This action is aimed at assessing the adequacy of the psychomotor and speech development of the baby. Photostimulation can also be used to diagnose epileptic activity. A test is carried out using a light bulb that reproduces bright flashes in a given rhythm, while the child's eyes are closed, but he still sees the flashing and reacts to it.

The duration of the usual procedure does not exceed 30 minutes, but in some cases additional studies are needed. The doctor can apply the impact of sound stimuli, ask the child to clench and unclench his fists and conduct psychological tests. Also, photostimulation at higher frequencies is sometimes carried out, preliminary dark adaptation, which involves the baby being in a darkened room for 40 minutes, or recording readings during the entire period of night sleep.

Analysis of results

As a result of the EEG, a document called an electroencephalogram is formed, on which the activity of neurons in various parts of the brain is reflected in the form of curved lines. Currently, the results of the procedure are recorded not only on paper, but also in a computer program, which greatly simplifies the process of analyzing the data obtained. New technologies make it possible to conduct EEG spectral analysis, view individual sections, calculate their frequency and amplitude, convert oscillations into diagrams, maps and tables. All this provides the doctor with clear and accurate data, on the basis of which he can make a diagnosis.

Having received the result of the study, parents should remember that decoding the EEG of the brain is the prerogative of the attending physician. The fact is that in encephalography there is no clear concept of age norms, the activity of brain impulses in each child is individual, especially for infants. Therefore, only a doctor can draw conclusions, who will take into account not only the result of a brain study, but also additional tests, as well as epicrises of other specialists.

It is worth noting that encephalography is an absolutely safe procedure that can be repeated many times. At the same time, it is important that parents save the EEG results, because at a young age the nervous system is only maturing and the characteristics of its activity are very variable. Thanks to the protocols of encephalography at different periods, the doctor will be able to monitor the dynamics of brain development and adequately assess the picture of the disease.

In medicine, to study the functions of the brain, a diagnostic procedure is used - electroencephalography (EEG). A harmless and affordable method is often used in pediatric neurology.

What is the research. How is the procedure carried out? Do I need to prepare for it? What is EchoEG and EchoES? When are these methods used? Let's look into these issues

What is an EEG

Electroencephalogram (EEG) is designed to determine the state of the brain in children and adults. The method is based on the registration of impulses that create and transmit neurons. The joint activity of these cells forms the bioelectrical activity of the cerebral cortex, which is recorded by the apparatus.

The electrodes record the signals and transmit them to the device. A computer program analyzes and processes information according to age and time of day.

Indicators are recorded in the form of a curve similar to a cardiogram. Electroencephalography in children is a safe way to obtain information about the functioning of the brain at any age. EEG data allows the doctor to detect the cause of the disease in the child in order to prescribe the correct treatment.

Who does an EEG

An encephalogram for a child is prescribed by a neurologist and a neurophysiologist. The procedure is done at any age - from birth to 18 years.

It is shown to do an EEG in the following cases:

• head injury;
• prolonged crying for no apparent reason;
• sleep disturbance of the baby - drowsiness or insomnia;
• unstable blood pressure in adolescents;
• convulsions of unknown origin;
• vegetative crises;
• irritability;
• rapid depletion of a physical resource;
• sleepwalking - night walking in an unconscious state;
• loss of consciousness;
• fainting;
• speech delay in children;
• convulsions at elevated temperature;
• EEG is done to children with stuttering.

Neurologists prescribe a study in this way in violation of consciousness and vegetovascular crises with fainting.

What does a doctor see on an EEG?

An encephalogram of the child's brain reveals the consistency of brain structures during sleep and wakefulness.

What does the EEG show:

• The stage of brain maturity in young children;
• ischemia and hypoxia of cerebral vessels;
• diagnosis of the severity of the disease;
• evaluation of the effectiveness of anticonvulsants;
• identification of the cause of the convulsive syndrome;
• the presence in the brain of a focus of convulsive activity;
• localization of damage.

EEG reveals meningitis, encephalitis against the background of herpes and other infectious diseases. The procedure reveals concussion and brain contusion.

EEG detects cerebral palsy, epilepsy. Thanks to the study, the doctor determines the cause of the lag in speech skills, memory loss.

How to prepare a child for an EEG

No specific preparation is required for the study. For the procedure of the encephalogram of the child's brain, they are prepared in advance by simple actions. To improve the contacts of the sensor with the hair, wash your hair the day before.

Infants EEG is carried out during sleep. Before the session, the child is fed. For children after 1 year, the procedure is done in a state of wakefulness. In order for the baby to behave calmly, the parents psychologically prepare the child the night before.

Tips for parents:

• Talk about diagnostics as a fun game of astronauts. During the procedure, a cap with sensors is put on the head, which represents the spacesuit. It is useful to show the baby a picture of an astronaut.
• Take your favorite toys with you to the examination, with which the baby will feel protected.
• An hour before the procedure, the baby is fed.

Before the session, hairpins and jewelry are removed from the baby’s head and her hair is loosened. Important! Parents should be aware that the examination is not done during fever, cough or nasal congestion.

How is an EEG test performed?

The procedure is done in a sound and light proof room. A hat is put on the child's head, on which sensors are pinned. Using wires, the electrodes are connected to the apparatus. The sensors are pre-lubricated with gel to avoid an air cushion. Clip-on earrings are put on the earlobes.

Babies during the procedure lie on the changing table or mother's arms.

Older children go through a more complex procedure. For this patient is placed on the couch. In the reclining position, the head cannot be bent.

During the session, provocative tests are used:

1. First, a background recording of the bioelectrical activity of neurons is made for 15 minutes.
2. The child is asked to open and close his eyes several times at intervals. The test is necessary to study the brain at rest and the transition to activity.
3. The next exercise is hyperventilation. The child takes a deep breath and exhale 2-3 times intermittently. The test reveals a latent tumor, epilepsy and a stressful state of the nervous system.
4. Another provocative test is photostimulation. The procedure is performed using an electric light bulb. The closed eyes of the child are illuminated with flashes of light several times. Light load on vision reveals epilepsy, the degree of activity of speech and psychomotor development of children.

The procedure lasts half an hour. If provocative tests do not reveal pathology, an EEG with sleep deprivation is performed.

For this, the child is woken up several hours earlier than usual. If a paroxysmal state of the brain or a deep sleep disorder is suspected, a night EEG is done.

EEG interpretation

4 types of rhythms are recorded on the tape. The EEG is deciphered by a doctor. A "bad" EEG during seizures is indicated by frequent electrical discharges of high amplitude. At the end of the attack, bioelectric activity decreases. Outside of convulsions, the apparatus fixes foci of increased convulsive activity.

In other brain pathologies, focal or diffuse changes are recorded on the tape. In tumors and strokes, a slow rhythm is noted with a predominance of beta waves. Diffuse changes are noted with encephalitis, meningitis, concussion or brain injury.

After injury, the frequency of the alpha rhythm increases. With dementia, this indicator is completely absent. If diffuse beta rhythms are detected, this indicates a concussion.

What is EchoEG

Echoencephalography of the brain (Echoeg) is an ultrasound examination using expert-class equipment with an advanced computer program.

The advantages of Echoeg are that it reveals pathology not only in the depths of the brain, but also near the bones of the skull:

• intracranial hematoma;
• intracranial pressure;
• degree of hydrocephalus;
• brain tumors;
• abscess.

The informativeness of the method is equal to magnetic resonance imaging and replaces it in case of contraindications to the latter.

What is the EchoES method

Echoencephaloscopy (Echoes) is an ultrasound scan of brain structures. The study is based on echolocation. The method allows you to receive signals from the ventricles of the brain. It is resorted to in case of suspicion of hypertension syndrome.

The need for the method arises with such a brain pathology:

• perinatal encephalopathy that developed during gestation or during childbirth;
• attention deficit disorder;
• stuttering;
• traumatic brain injury;
• sleep disturbance:
• increased activity;
• enuresis.

No preparation is required before the study. The method is harmless, therefore it is used in children and pregnant women.

An electroencephalogram is necessary to detect or exclude brain pathology. The procedure can be done several times without harming a child of any age. In severe brain pathology, in addition to the EEG, an improved study of Echoeg and Echoes is used.

Electroencephalography or EEG is a highly informative study of the functional features of the central nervous system. Through this diagnosis, possible violations of the central nervous system, and their causes, are established. Deciphering the EEG in children and adults gives a detailed idea of ​​the state of the brain and the presence of abnormalities. Allows you to identify individual affected areas. The results determine the neurological or psychiatric nature of the pathologies.

Prerogative aspects and disadvantages of the EEG method

Neurophysiologists and patients themselves prefer EEG diagnostics for several reasons:

• reliability of results;
• no contraindications for medical reasons;
• the ability to perform a study in a sleeping, and even unconscious state of the patient;
• lack of gender and age boundaries for the procedure (EEG is done for both newborns and the elderly);
• affordability and territorial accessibility (the examination has a low cost and is carried out in almost every district hospital);
• insignificant time costs for conducting a conventional electroencephalogram;
• painlessness (during the procedure, the child may be capricious, but not from pain, but from fear);
• harmlessness (electrodes fixed on the head register the electrical activity of brain structures, but do not have any effect on the brain);
• the possibility of conducting multiple examinations to track the dynamics of the prescribed therapy;
• prompt interpretation of the results for diagnosis.

In addition, no preliminary preparation is provided for the EEG. The disadvantages of the method include the possible distortion of indicators for the following reasons:

• unstable psycho-emotional state of the child at the time of the study;
• mobility (during the procedure, it is necessary to observe the static head and body);
• the use of medications that affect the activity of the central nervous system;
• hungry state (a decrease in sugar levels against the background of hunger affects brain function);
• chronic diseases of the organs of vision.

In most cases, the listed reasons can be eliminated (conduct a study during sleep, stop taking medication, provide the child with a psychological attitude). If the doctor has prescribed electroencephalography for the baby, the study cannot be ignored.

Diagnosis is not carried out for all children, but only according to indications

Indications for examination

Indications for the appointment of a functional diagnosis of the nervous system of a child can be of three types: control-therapeutic, confirming / refuting, symptomatic. The former include mandatory research after behavioral neurosurgical operations and control and preventive procedures for previously diagnosed epilepsy, dropsy of the brain or autism. The second category is represented by medical assumptions about the presence of malignant neoplasms in the brain (EEG is able to detect an atypical focus earlier than magnetic resonance imaging will show this).

Alarming symptoms for which the procedure is prescribed:

• A child's lag in speech development: a violation of pronunciation due to a functional failure of the central nervous system (dysarthria), a disorder, loss of speech activity due to an organic lesion of certain areas of the brain responsible for speech (aphasia), stuttering.
• Sudden, uncontrolled seizures in children (possibly epileptic seizures).
• Uncontrolled emptying of the bladder (enuresis).
• Excessive mobility and excitability of babies (hyperactivity).
• Unconscious movement of the child during sleep (sleepwalking).
• Concussions, bruises and other head injuries.
• Systematic headaches, dizziness and fainting, of uncertain origin.
• Involuntary muscle spasms at an accelerated pace (nervous tic).
• Inability to concentrate (distracted attention), decreased mental activity, memory disorder.
• Psycho-emotional disorders (unreasonable mood swings, a tendency to aggression, psychosis).

How to get correct results?

EEG of the brain in children of preschool and primary school age, most often, is carried out in the presence of parents (babies are held in their arms). Special training is not carried out, parents should follow a few simple recommendations:

• Examine the child's head carefully. In the presence of minor scratches, wounds, scratching, inform the doctor. Electrodes are not attached to areas with damaged epidermis (skin).
• Feed the child. The study is carried out on a full stomach, so as not to lubricate the indicators. (Sweets containing chocolate, which excites the nervous system, should be excluded from the menu). As for infants, they must be fed immediately before the procedure in a medical facility. In this case, the baby will calmly fall asleep and the study will be carried out during sleep.

It is more convenient for babies to conduct research during natural sleep

It is important to stop taking medications (if the baby is receiving treatment on an ongoing basis, you need to notify the doctor about this). Children of school and preschool age need to be explained what they have to do and why. The right mental attitude will help to avoid excessive emotionality. You are allowed to take toys with you (excluding digital gadgets).

Hairpins, bows should be removed from the head, earrings should be removed from the ears. Girls should not wear braids. If the EEG is done again, it is necessary to take the protocol of the previous study. Before the examination, the child's hair and scalp should be washed. One of the conditions is the well-being of the little patient. If the child has a cold, or there are other health problems, it is better to postpone the procedure until complete recovery.

Methodology

According to the method of conducting, the electroencephalogram is close to the electrocardiography of the heart (ECG). In this case, 12 electrodes are also used, which are symmetrically placed on the head in certain areas. The imposition and fastening of sensors to the head is carried out in a strict order. The scalp at the points of contact with the electrodes is treated with a gel. The installed sensors are fixed on top with a special medical cap.

By means of clips, the sensors are connected to an electroencephalograph - a device that records the features of brain activity and reproduces the data on a paper tape in the form of a graphic image. It is important that the little patient keeps his head straight throughout the examination. The time interval of the procedure, together with the mandatory testing, is about half an hour.

The ventilation test is carried out for children from 3 years of age. To control breathing, the child will be asked to inflate the balloon for 2-4 minutes. This testing is necessary to establish possible neoplasms and diagnose latent epilepsy. Deviation in the development of the speech apparatus, mental reactions will help to identify light irritation. An in-depth version of the study is carried out according to the principle of daily Holter monitoring in cardiology.

Cap with sensors does not cause pain or discomfort to the child

The baby wears a cap for 24 hours, and a small device located on the belt continuously records changes in the activity of the nervous system as a whole and individual brain structures. After a day, the device and cap are removed and the doctor analyzes the results. Such a study is of fundamental importance for the detection of epilepsy in the initial period of its development, when the symptoms do not yet appear often and clearly.

Deciphering the results of the electroencephalogram

Only a highly qualified neurophysiologist or neuropathologist should deal with the decoding of the results obtained. It is quite difficult to determine deviations from the norm on the graph if they do not have a pronounced character. At the same time, the normative indicators can be interpreted differently depending on the age category of the patient and the state of health at the time of the procedure.

It is almost impossible for a non-professional person to correctly understand the indicators. The process of transcribing the results may take several days, due to the scale of the analyzed material. The physician must evaluate the electrical activity of millions of neurons. Evaluation of children's EEG is complicated by the fact that the nervous system is in a state of maturation and active growth.

The electroencephalograph registers the main types of activity of the child's brain, displaying them in the form of waves, which are evaluated according to three parameters:

• The frequency of wave oscillations. The change in the state of the waves in a second time interval (oscillations) is measured in Hz (hertz). In conclusion, an average indicator is recorded, obtained by the average wave activity per second in several sections of the graph.
• The range of wave changes or amplitude. Reflects the distance between opposite peaks of wave activity. It is measured in µV (microvolts). The protocol describes the most characteristic (frequent) indicators.
• Phase. According to this indicator (the number of phases per one oscillation), the current state of the process or changes in its direction are determined.

In addition, the rhythm of the heart and the symmetry of the activity of neutrons in the hemispheres (right and left) are taken into account. The main evaluative indicator of brain activity is the rhythm that is generated and regulated by the most complex structure of the brain (thalamus). Rhythm is determined by the form, amplitude, regularity and frequency of wave oscillations.

Types and norms of rhythms

Each of the rhythms is responsible for one or another brain activity. To decode the electroencephalogram, several types of rhythms are used, denoted by the letters of the Greek alphabet:

• Alpha, Betta, Gamma, Kappa, Lambda, Mu - characteristic of an awake patient;
• Delta, Theta, Sigma - characteristic of the state of sleep or the presence of pathologies.

The interpretation of the results is carried out by a qualified specialist

First appearance:

• α-rhythm. It has an amplitude standard of up to 100 μV, frequencies - from 8 Hz to 13. It is responsible for the calm state of the patient's brain, in which its highest amplitude indicators are noted. With the activation of visual perception or brain activity, the alpha rhythm is partially or completely inhibited (blocked).
• β-rhythm. The frequency of fluctuations is normally from 13 Hz to 19 Hz, the amplitude is symmetrical in both hemispheres - from 3 μV to 5. The manifestation of changes is observed in a state of psycho-emotional arousal.
• γ-rhythm. Normally, it has a low amplitude of up to 10 μV, the oscillation frequency varies from 120 Hz to 180. It is determined on the EEG with increased concentration and mental stress.
• κ-rhythm. Digital indicators of fluctuations range from 8 Hz to 12.
• λ-rhythm. It is included in the overall work of the brain if necessary, visual concentration in the dark or with eyes closed. Stopping the gaze at a certain point λ-rhythm blocks. Has a frequency of 4 Hz to 5.
• μ-rhythm. It is characterized by the same interval as the α-rhythm. It manifests itself with the activation of mental activity.

The manifestation of the second type:

• δ-rhythm. Normally recorded in a state of deep sleep or coma. A wakefulness manifestation may mean cancerous or dystrophic changes in the area of ​​the brain from which the signal was received.
• τ-rhythm. It ranges from 4 Hz to 8. The startup process is carried out in a sleep state.
• Σ-rhythm. The frequency ranges from 10 Hz to 16. Occurs in the stage of falling asleep.

The combination of characteristics of all types of brain rhythm determines the bioelectrical activity of the brain (BEA). According to the standards, this evaluation parameter should be characterized as synchronous and rhythmic. Other variants of the description of BEA in the doctor's conclusion indicate violations and pathologies.

Possible violations on the electroencephalogram

Violation of rhythms, the absence / presence of certain types of rhythm, asymmetry of the hemispheres indicate failures of brain processes and the presence of diseases. Asymmetry of 35% or more may be a sign of a cyst or tumor.

Electroencephalogram readings for alpha rhythm and provisional diagnoses

Parameters of beta rhythm

Parameters of δ- and τ-rhythm

In addition to the parameters described, the age of the child being examined is taken into account. In infants up to six months of age, theta fluctuations are continuously increasing in quantity, while delta fluctuations are falling. From the age of six months, these rhythms rapidly fade away, and alpha waves, on the contrary, are actively formed. Up to school, there is a stable replacement of theta and delta waves by β and α waves. During puberty, the activity of alpha rhythms prevails. The final formation of the set of wave parameters or BEA is completed by adulthood.

Failures of bioelectrical activity

Relatively stable bioelectroactivity with signs of paroxysm, regardless of the area of ​​the brain where it manifests itself, indicates the prevalence of excitation over inhibition. This explains the presence of a systematic headache in a neurological disease (migraine). The combination of pathological bioelectroactivity and paroxysm is one of the signs of epilepsy.

Reduced BEA characterizes depressive states

Extra options

When decoding the results, any nuances are taken into account. The decoding of some of them is as follows. Signs of frequent irritation of the brain structures indicate a violation of the process of blood circulation in the brain, insufficient blood supply. Focal abnormal activity of rhythms is a sign of predisposition to epilepsy and convulsive syndrome. The discrepancy between neurophysiological maturity and the age of the child indicates a developmental delay.

Violation of wave activity indicates past craniocerebral trauma. The predominance of active discharges from any brain structure and their amplification during physical stress can cause serious disturbances in the functioning of the hearing apparatus, organs of vision, and provoke a short-term loss of consciousness. In children with such manifestations, it is necessary to strictly control sports and other physical activities. Slow alpha rhythm can cause increased muscle tone.

The most common EEG-based diagnoses

Common diseases that are diagnosed by a neurologist in children after the study include:

• Brain tumor of various etiology (origin). The cause of the pathology remains unclear.
• Traumatic brain injury.
• Simultaneous inflammation of the membranes of the brain and medulla (meningoencephalitis). The most common cause is an infection.
• Abnormal accumulation of fluid in brain structures (hydrocephalus or dropsy). Pathology is congenital. Most likely, during the perinatal period, the woman did not undergo mandatory screenings. Or the anomaly developed as a result of an injury received by the infant during delivery.
• Chronic neuropsychiatric disease with characteristic convulsive seizures (epilepsy). The provoking factors are: heredity, trauma during childbirth, neglected infections, antisocial behavior of a woman while carrying a baby (drug addiction, alcoholism).
• Hemorrhage into the substance of the brain, due to rupture of blood vessels. It can be triggered by high blood pressure, head injuries, blockage of blood vessels by cholesterol growths (plaques).
• Infantile cerebral palsy (ICP). The development of the disease begins in the prenatal period under the influence of adverse factors (oxygen starvation, intrauterine infections, exposure to alcoholic or pharmacological toxins) or head trauma during delivery.
• Unconscious movements during sleep (sleepwalking, somnambulism). There is no exact explanation for the reason. Presumably, these may be genetic abnormalities or the influence of adverse natural factors (if the child was in an environmentally hazardous area).

With diagnosed epilepsy, EEG is performed regularly

Electroencephalography makes it possible to establish the focus and type of disease. On the graph, the following changes will be the distinguishing features:

• acute-angled waves with a sharp rise and fall;
• pronounced slow pointed waves in combination with slow ones;
• a sharp increase in amplitude by several units of kmV.
• when testing for hyperventilation, vasoconstriction and spasms are recorded.
• during photostimulation, unusual reactions to the test appear.

If epilepsy is suspected and on a control study of the dynamics of the disease, testing is carried out in a sparing mode, since the load can cause an epileptic seizure.

Traumatic brain injury

Changes in the schedule depend on the severity of the injury. The stronger the blow, the brighter the manifestations will be. The asymmetry of the rhythms indicates an uncomplicated injury (mild concussion). Uncharacteristic δ-waves accompanied by bright flashes of δ- and τ-rhythm and imbalance of α-rhythm can be a sign of bleeding between the meninges and the brain.

An area of ​​the brain damaged as a result of an injury always declares itself to be of increased activity of a pathological nature. With the disappearance of concussion symptoms (nausea, vomiting, severe headaches), deviations will still be recorded on the EEG. If, on the contrary, the symptoms and electroencephalogram indicators worsen, extensive brain damage will be a possible diagnosis.

According to the results, the doctor may recommend or oblige to undergo additional diagnostic procedures. If it is necessary to examine the brain tissue in detail, and not its functional features, magnetic resonance imaging (MRI) is prescribed. If a tumor process is detected, computed tomography (CT) should be consulted. The final diagnosis is made by a neuropathologist, summarizing the data reflected in the clinical and electroencephalographic report and the patient's symptoms.

It should be noted here that some (probably to enhance the significance of the study) talk about the 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 of the medical term - encephalography.

Electroencephalography or EEG is a method of studying the brain (GM) 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 GM (frequency, amplitude), and this is done using electrodes attached in different places on the surface of the head.

What kind of study is an EEG?

Periodically coming convulsive seizures, occurring in most cases with a complete loss of consciousness, are popularly called an epilepsy, which official medicine calls epilepsy.

The very first and main method for diagnosing this disease, serving humanity for many decades (the first EEG taken is dated 1928), is encephalography (electroencephalography). Of course, the research apparatus (encephalograph) has significantly changed and improved by now, its capabilities with the use of computer technology have significantly expanded. However, the essence of the diagnostic method remained the same.

The 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 fixes them on paper in the form of a broken line, very reminiscent of an ECG.

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

• Thalamus, which oversees and redistributes information;
• ARS (activating reticular system), the nuclei of which, settled in various parts of the GM (medulla 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 apparatus where the recording takes place (a graphic image is an encephalogram). The processing and analysis of information are the tasks of computer software that “knows” the norms of the biological activity of the brain and the formation of biorhythms depending on age and a specific situation.

For example, routine EEG captures the formation of pathological rhythms during an attack or in the period between seizures, sleep EEG or nighttime EEG monitoring shows how the biopotentials of the brain change during immersion 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 during sleep and answers the questions:

1. Are there foci of increased convulsive readiness of GM, and if they are, in what area are they located;
2. At what stage is the disease, how far has it gone or, on the contrary, has begun to regress;
3. What effect does the chosen medicine give and whether its dose is correctly calculated;

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

Features of the EEG in children

What can we say about babies, if some adults, having received an EEG referral, begin to ask what and how, because they doubt the safety of this procedure. Meanwhile, it actually cannot bring any harm to the child, but it is really difficult to make an EEG for a small patient. Babies under one year of age measure the bioelectrical activity of the brain during sleep, before that they wash their hair, feed the baby and, without deviating from the usual schedule (sleep / wakefulness), adjust the procedure to the child's sleep.

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

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

Indications for daytime sleep encephalography or nocturnal EEG in a child are:

• Identification of paroxysmal conditions of various origins - epileptic seizures, convulsive syndrome against the background of high body temperature (febrile convulsions), epileptiform seizures that are not associated with true epilepsy and are differentiated from it;
• Monitoring the effectiveness of antiepileptic therapy in case of an established diagnosis of epilepsy;
• Diagnosis of hypoxic and ischemic lesions of the central nervous system (presence and severity);
• Determining the severity of brain lesions for prognostic purposes;
• The 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 with vegetative-vascular dystonia with frequent fainting spells and dizziness, with a delay in acquiring speech skills and stuttering. This method should not be neglected in other cases that require the study of the reserves of the functional capabilities of the brain, because the procedure is harmless and painless, but it can provide maximum information for diagnosing a certain pathology. Electroencephalography is very useful if there are episodes of disturbances of consciousness, but their cause has not been elucidated.

Various Recording Methods

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

1. At the beginning of a diagnostic search that reveals the causes of paroxysmal conditions, a short (≈ 15 min) routine method of recording an encephalogram is used, which involves the use of provocative tests to identify hidden disorders - the patient is asked to breathe deeply (hyperventilation), open and close his eyes, or give light stimulation (photostimulation);
2. If the routine EEG did not provide the necessary information, then the doctor prescribes encephalography with deprivation (deprivation of sleep at night in whole or in part). In order to conduct such a study and obtain reliable results, a person is either not allowed to sleep at all, or they wake him up 2-3 hours before the subject’s “biological alarm clock rings”;
3. A long-term EEG recording with registration of the bioelectrical activity of the cerebral cortex during the “quiet hour” (EEG of sleep) takes place if the doctor suspects that changes in the brain occur during the stay in the “sleep mode”;
4. Experts consider the night EEG to be the most informative, the recording of which is carried out in a hospital. They begin the study while still awake (before going to bed), continue when immersed in a nap, capture the entire period of night sleep and end after a natural awakening. If necessary, the registration of the bioelectrical activity of the GM is supplemented by the application of supernumerary electrodes and the use of video recording equipment.

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

Time and equipment form the price

In other cases, there is a need to measure the GM biopotentials at the time of an attack. In pursuit of such goals, the patient, as well as for conducting a night EEG, is sent to a hospital for hospitalization, where daily EEG monitoring is carried out using audio and video equipment. Continuous EEG monitoring with video recording during the day makes it possible to verify the epileptic origin of paroxysmal memory disorders, isolated auras, as well as episodically occurring psychomotor phenomena.

Electroencephalography is one of the most accessible methods for studying the brain. And for the price too. In Moscow, you can find this study for 1,500 rubles, and for 8,000 rubles (EEG sleep monitoring for 6 hours), and for 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), as well as get a doctor's consultation immediately after the test or quickly resolve the issue regarding other methods of brain research.

About the main rhythms of the electrical activity of the GM

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

The electroencephalogram is composed of various complex biorhythms emanating from the electrical activity of the GM in different periods of time, depending on specific situations.

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

• Alpha rhythm (frequency - in the range from 9 to 13 Hz, amplitude of oscillations - from 5 to 100 μV), which is present in almost all people who do not make claims to their health during inactive wakefulness (relaxation during rest, relaxation, shallow meditation). As soon as a person opens his eyes and tries to visualize 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, activation of autonomic nervous activity;
• The beta-rhythm (the frequency is in the range from 13 to 39 Hz, the amplitude of oscillations is up to 20 μV) is not only the mode of our wakefulness, the β-rhythm is characteristic of active mental work. In the normal state, the severity of β-waves is very weak, their excess indicates an immediate reaction of the GM to stress;
• Theta-rhythm (frequency - from 4 to 8 Hz, amplitude is within µV). These waves do not reflect a pathological change in consciousness, for example, a person is dozing, is in a half-sleep, in the stage of superficial sleep, he already sees some dreams, and then θ-rhythms are detected. In a healthy person, falling into sleep is accompanied by the appearance of a significant number of θ-rhythms. An increase in theta rhythm is observed with prolonged psycho-emotional stress, mental disorders, twilight states characteristic of some neurological diseases, asthenic syndrome, concussion of the brain;
• Delta rhythm (frequency is in the range from 0.3 to 4 Hz, amplitude - from 20 to 200 μV) - is characteristic of deep immersion in 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 that reach a high frequency (up to 100 Hz), kappa rhythms that form in the temporal leads during active mental activity, and mu rhythms associated with mental stress. These waves are not particularly interesting in the diagnostic sense, since they occur with a significant mental load and intense "thought work" that requires a high concentration of attention. The electroencephalogram, as you know, is recorded, although during wakefulness, but in a calm state, and in some cases night monitoring of the EEG or EEG of sleep is generally prescribed.

Video: alpha and beta rhythms on the EEG

EEG decoding

main EEG leads and their designations

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

• In the occipito-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 of more 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 referred to as normal variants.

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

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, showing all the clinical symptoms of the pathology at the time of a convulsive seizure. Moreover, paroxysmal manifestations in other cases can be recorded in people who are absolutely healthy, who do not have any signs and prerequisites for the development of a convulsive syndrome.

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

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

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

If the origin of the GM lesion is established, and diffuse changes are recorded on the EEG, then the diagnostic value of this study, although not so significant, still allows you to find one or another disease that is far from epilepsy:

• Meningitis, encephalitis (especially those caused by herpes infection) - on the EEG: periodic formation of epileptiform discharges;
• Metabolic encephalopathy - on the encephalogram: the presence of "three-phase" waves or diffuse slowdowns in rhythm and outbreaks of symmetrical slow activity in the frontal areas.

Diffuse changes on 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 present any complaints and consider themselves absolutely healthy. It also happens, and if there are no clinical manifestations of pathology, then there is no reason for concern either. Perhaps at the next examination, the EEG record will reflect the full norm.

When is an EEG helpful in making a diagnosis?

Electroencephalography, revealing the functional capabilities and reserves of the central nervous system, has become the standard for studying the brain; doctors consider it appropriate to conduct it in many cases and under 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 - according to the situation);
2. With various sleep disorders (insomnia, drowsiness, frequent nocturnal awakenings, etc.);
3. In the presence of convulsions and epileptic seizures;
4. To confirm or exclude complications of inflammatory processes caused by neuroinfection;
5. With vascular lesions of the brain;
6. After TBI (brain contusion, concussion) - EEG shows the depth of suffering of the GM;
7. To assess the severity of the consequences of exposure to neurotoxic poisons;
8. In the case of the development of an oncological process affecting the central nervous system;
9. With mental disorders of various kinds;
10. Conduct EEG monitoring in assessing the effectiveness of anticonvulsant therapy and the selection of optimal dosages of therapeutic agents;
11. The reason for doing an EEG may be signs of dysfunction of brain structures in children and suspicion of degenerative changes in the nervous tissue of the brain in the elderly (dementia, Parkinson's disease, Alzheimer's disease);
12. Patients who are in a coma need an assessment of the state of the brain;
13. In some cases, the study requires surgery (determination of the depth of anesthesia);
14. How far neuropsychiatric disorders have gone in hepatocellular insufficiency (hepatic encephalopathy), as well as in other forms of metabolic encephalopathies (renal, hypoxic), encephalography will help to recognize;
15. All drivers (future and current) when passing a medical examination to obtain / replace rights are offered to pass an EEG for a certificate provided by the traffic police. The survey is available in use and easily identifies those who are completely unfit to drive vehicles, therefore it was adopted;
16. Assign electroencephalography to conscripts with a history of convulsions (based on medical records) or in case of complaints of seizures with loss of consciousness accompanied by convulsions;
17. In some cases, such a study as an EEG is used to ascertain the death of a significant part of nerve cells, that is, brain death (we are talking about situations where they say that “a person most likely turned into a plant”).

Video: EEG and epilepsy detection

The study does not require special preparation

EEG does not require special preparation, however, some patients are frankly afraid of the upcoming procedure. It's no joke - sensors with wires are placed on the head, which read "everything that happens 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, 12 are enough for a small child.

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

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

• For 2 days they refuse alcohol (strong and weak), do not use drinks stimulating the nervous system, do not regale themselves with chocolate;
• Before the study, they receive doctor's advice regarding the medications taken (hypnotics, tranquilizers, anticonvulsants, etc.). It is possible that individual drugs, having agreed with the attending doctor, will have to be canceled, and if this cannot be done, then you should inform the doctor who will decipher the encephalogram (mark in the referral form) so that he has in mind these circumstances and takes them into account when drawing up the conclusion.
• 2 hours before the examination, patients should not allow themselves a hearty 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 illness, as well as with coughing and nasal congestion, even if these signs do not belong to an acute process.

When all the rules of the preparatory stage are observed, certain moments are taken into account, the patient is seated in a comfortable chair, the points of contact of the head surface with the electrodes are lubricated with gel, sensors are attached, a hat is put on or dispensed with, the device is turned on - the recording has started ... 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 of the eyes, sleep, light irritation, sleep deprivation) activate the electrical activity of the GM cortex, the electrodes pick up the impulses sent by the cortex and transmit it 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 officially recognized that in many cases it is the nasopharyngeal lead that detects the focus of epileptic activity in the temporal region, while other leads do not react to it in any way and send normal impulses.

What are the results of the EEG procedure for adults and children

Electroencephalography (EEG) is designed to assess the state of the brain. Thanks to this method of examination, many diseases that are directly related to the vascular system are detected. For example, this examination method is prescribed to detect tumors, epilepsy and inflammatory diseases.

EEG characteristic

The method of examination is the only one that is used even if an adult is unconscious.

Encephalography does absolutely no harm to the body. The method is even used on children if it is required to identify or prevent the development of any disease.

Thanks to the EEG of the brain in children, they monitor the dynamics of the development of the disease, how effective the therapy prescribed by the doctor is, and also to determine possible complications. A chance to evaluate changes in the brain is given. This procedure is carried out as soon as the patient has a concussion in question. Don't be afraid to do a survey. It does not bring discomfort, and is also harmless.

The values ​​obtained from an EEG are similar to an ECG, which is done to check the functioning of the cardiovascular system. The results are presented in the form of a curve that shows the activity and work of the brain. The doctor deciphers the results and the diagnosis is clarified, with which they go for additional examinations.

Proper functioning of the brain is an integral part of the normal functioning of the adult body. Therefore, they sometimes check how well he works out all the processes.

How is the procedure

The study takes place in several stages, which require a little time. The procedure will take half an hour.

1. First of all, there is a usual measurement of brain activity. This lasts for 10 minutes. The results of its inactive state are recorded, as well as when a person is in an active state.
2. If the usual examination did not show results, then a complex one is carried out, which involves sleep disturbance. A person either does not sleep the night before the procedure, or he is specially woken up a few hours before he wakes up.
3. Sometimes a procedure is prescribed during sleep. It is quite long, but gives a good result of the examination.
4. Effective results of the study will be shown early in the morning, during sleep and before bedtime. Brain activity at this time is in a normal state and the brain does not yet have time to load all the situations that occur during the day.

Important. If epilepsy is suspected, often the sensors are located at the temples, which helps to determine the presence of this disease with an accurate probability. This is due to the fact that it is the nasopharyngeal abduction that gives an informative response in epilepsy.

When to do an EEG

A person does not just do electroencephalography. This requires a doctor's referral, which is issued based on the patient's complaints or the situation that has happened. The procedure is safe, but doctors first prefer to collect information about the disease, and only then send it for examination. When a diagnosis cannot be made, doctors begin to prescribe brain tests, including EEG.

EEG indications:

• If the child does not speak independently about his feelings. As a rule, it is small children who cannot explain what is happening to them. To do this, doctors prefer to immediately prescribe an examination in a way that will be informative.
• If a person has a long-term sleep disturbance or prolonged insomnia.
• Epilepsy.
• Suspicion of a brain tumor.
• Concussion.
• Skull injury.
• The person has a mental disorder. For example, this is often expressed in recurrent nervous breakdowns or psychoses.
• Coma.

Conducting electroencephalography in children

The procedure does not harm the baby. So don't worry about his condition after. But the examination itself is inconvenient. Babies only do it when they are sleeping. Before this, the child’s head is washed, later he is fed and put to bed. Thus, the procedure will go well. It is important to understand that the procedure is carried out strictly in the personal schedule of sleep and wakefulness of the child, without knocking down the regimen. Otherwise, the baby will not be calm during the examination.

It is easier for infants to conduct an examination, which cannot be said about older children. If babies are easy enough to feed, and they fall asleep with pleasure, then children of the age of 3 years are difficult to persuade to go to bed. That is why during the wakefulness period such a procedure is carried out only for calm children.

It is advisable to prepare the child mentally for this procedure in a few days. Thus, turning the examination into a kind of game that he wants to go to without too much hysteria.

The indications for encephalography in a child are as follows:

1. Identification of any kind of diseases, for example, epilepsy, hypoxia, convulsions and others that bother the child for a long time.
2. Excessive nervous state, which leads to nervous breakdowns and psychos. This indicates an unstable work of the nervous system, as well as various diseases that are irritants.
3. With the help of such a study, the effectiveness of the therapy that was prescribed by the doctor for epilepsy is determined.
4. Determination of the presence of diseases of the central nervous system.
5. It is carried out for young children in order to assess the activity of the brain, as well as the correctness of its development. Such an examination is carried out for those children who have had hypoxia since birth.
6. Examination of the skull and brain after injury, which may be caused by a car accident, a fall, a blow, or other mechanical damage.
7. Tumor suspected. In children, oncological disease of the brain is extremely rare, but still occurs. The procedure is carried out if oncology of other organs is noted, in the advanced stage of which it gives metastases to the entire body.
8. EEG is prescribed for VVD, which is accompanied by fainting and constant headache. Sometimes there are children with delayed speech development who require such an examination to see the cause.

Important. Do not be afraid to conduct an EEG several times if necessary. The procedure does not have negative consequences.

Preparation for electroencephalography

The procedure is simple and harmless, but requires special training, which everyone can handle. Training concerns mainly the female gender.

Before the procedure, wash your hair with a simple shampoo. Styling should be done without additional products, for example, without using foams, gels and hair sprays. If the patient has dreadlocks, then you should be prepared for the fact that they will have to be untwisted.

From the whole body and ears, all metal is removed in the form of jewelry. This is due to the fact that the procedure is the occurrence of a small electrical flow, which just controls the entire process.

In the event that such an examination will be carried out on a child, it is advisable to check with the doctor for all the details. Take your favorite toy with you so that the child is distracted from what is happening. It is important to understand that at the time of the procedure, the child must be in an absolutely calm state. If before that he had experiences or he cried, then the examination will not show an informative result and you will have to do everything again.

The examination is not carried out for those people who suffer from colds and other viral diseases. They affect the processes occurring in the brain. A person must be completely healthy in this regard.

It is advisable to give up alcoholic beverages two days before the examination so that the brain assumes its normal state and begins to function normally. Also, the doctor should report on what drugs the patient is taking, for example, sleeping pills, sedatives, or others. Some of them are canceled a few days before the procedure. Sometimes it is impossible to cancel the drug and this will affect the person's condition. Warn the doctor about this, who will decipher the results so that he was aware and took this into account.

Important. A couple of hours before the procedure, it is undesirable to eat a lot, as well as smoke.

Procedure

First, a special cap is put on the patient's head, which is very similar to the one used for bathing. It is designed to fix the electrodes, the number of which in most cases depends on the age of the person. For people under the age of 18, 12 electrodes are placed, and for those who have reached the age of majority, the number increases to 21.

The electrode is filled with a special substance that helps to contact the brain and send impulses to it and back. Thus, all ongoing processes enter the computer and are recorded. It is from these results, which resemble a curve, that doctors decipher the meaning and draw a conclusion. Thanks to the examination, the doctor will be able to find out exactly which part of the brain is not working properly.

Significance of the survey

Naturally, at the present stage there are a large number of other examination methods, such as CT or MRI. But the EEG is still used, but is becoming less significant. This device is present in any hospital, and the procedure allows you not to spend a lot of money, but at the same time you can find out an informative result.

An important procedure for those suffering from epileptic seizures or epilepsy. Thanks to electroencephalography, the disease is determined at an early stage of development, which allows you to start timely treatment. At the same time, it is not required to look for a medical institution where they conduct a brain examination. Most often, such a device is in every clinic.

The EEG helps to show how effective the treatment that has been prescribed. In which case, it is corrected. People with an epileptic seizure are checked for changes by electroencephalography every 10 days, which is convenient and inexpensive. As a rule, such an examination is often carried out free of charge as prescribed by a doctor, while other procedures require payment and cannot be performed so often.

Benefits of electroencephalography

The main advantage is that the examination does not harm the body and it is carried out several times a month in order to control the dynamics of the prescribed treatment. The procedure does not negatively affect even a small child. The main thing is that it is carried out without problems. To do this, prepare for it in advance.

There is also an advantage in the low cost of the examination, especially when compared with other procedures such as MRI or CT.

The method of examination is informative in detecting epilepsy. Only electroencephalography helps to identify the disease, which will allow you to start timely treatment, which can only be prescribed by a doctor.

The survey will take a long time. As a rule, a person needs to find minutes for examination.

EEG (Electroencephalogram) - transcript

Electroencephalogram of the brain - definition and essence of the method

1. Photostimulation (exposure to flashes of bright light on closed eyes).

2. Opening and closing the eyes.

3. Hyperventilation (rare and deep breathing for 3-5 minutes).

• clenching fingers into a fist;
• sleep deprivation test;
• stay in the dark for 40 minutes;
• monitoring of the entire period of night sleep;
• taking medications;
• performing psychological tests.

Additional tests for EEG are determined by a neurologist who wishes to evaluate certain functions of the human brain.

What does an electroencephalogram show?

Where and how to do it?

Electroencephalogram for children: how the procedure is performed

Electroencephalogram rhythms

Electroencephalogram results

1. Description of the activity and typical affiliation of EEG waves (for example: "An alpha rhythm is recorded over both hemispheres. The average amplitude is 57 μV on the left and 59 μV on the right. The dominant frequency is 8.7 Hz. The alpha rhythm dominates in the occipital leads").

2. Conclusion according to the description of the EEG and its interpretation (for example: "Signs of irritation of the cortex and midline structures of the brain. Asymmetry between the cerebral hemispheres and paroxysmal activity was not detected").

3. Determination of the correspondence of clinical symptoms with the results of the EEG (for example: "Objective changes in the functional activity of the brain were recorded, corresponding to the manifestations of epilepsy").

Deciphering the electroencephalogram

Alpha - rhythm

• constant registration of the alpha rhythm in the frontal parts of the brain;
• interhemispheric asymmetry above 30%;
• violation of sinusoidal waves;
• paroxysmal or arcuate rhythm;
• unstable frequency;
• amplitude less than 20 μV or more than 90 μV;
• rhythm index less than 50%.

What do common alpha rhythm disturbances indicate?

Pronounced interhemispheric asymmetry may indicate the presence of a brain tumor, cyst, stroke, heart attack, or a scar at the site of an old hemorrhage.

• disorganization of the alpha rhythm;
• increased synchronicity and amplitude;
• moving the focus of activity from the nape and crown;
• weak short activation reaction;
• excessive response to hyperventilation.

A decrease in the amplitude of the alpha rhythm, a shift in the focus of activity from the nape and crown of the head, a weak activation reaction indicate the presence of psychopathology.

beta rhythm

• paroxysmal discharges;
• low frequency distributed over the convexital surface of the brain;
• asymmetry between the hemispheres in amplitude (above 50%);
• sinusoidal type of beta rhythm;
• amplitude more than 7 μV.

What do beta rhythm disturbances on the EEG indicate?

The presence of diffuse beta waves with an amplitude not higher than kV indicates a concussion.

Theta rhythm and delta rhythm

Delta waves with high amplitude indicate the presence of a tumor.

Bioelectrical activity of the brain (BEA)

Relatively rhythmic bioelectrical activity with foci of paroxysmal activity in any area of ​​the brain indicates the presence of a certain area in its tissue where excitation processes exceed inhibition. This type of EEG may indicate the presence of migraines and headaches.

Other indicators

• change in the electrical potentials of the brain according to the residual-irritative type;
• enhanced synchronization;
• pathological activity of the median structures of the brain;
• paroxysmal activity.

In general, residual changes in brain structures are the consequences of damage of a different nature, for example, after trauma, hypoxia, or a viral or bacterial infection. Residual changes are present in all brain tissues, therefore they are diffuse. Such changes disrupt the normal passage of nerve impulses.

• the appearance of slow waves (theta and delta);
• bilateral-synchronous disorders;
• epileptoid activity.

Changes progress as the volume of education increases.

Electroencephalogram: price of the procedure

Read more:

Leave feedback

You can add your comments and feedback to this article, subject to the Discussion Rules.