Under the complex name lies a safe, easy-to-perform method of studying the brain that captures electrical impulses and records their rhythm and frequency. An electroencephalogram of the brain provides information about the functional characteristics of this organ.

EEG is a test that can be performed on patients of all ages and in any condition. An electroencephalograph, a research device, is indispensable in intensive care wards. This is what is connected to patients in a coma to monitor the slightest changes in the electrical activity of the brain.

Electroencephalography can be carried out in parallel with the patient's exposure to irritating factors: sounds, light, sleep deprivation. This gives a clearer picture of the nature of the disorder and areas of epileptic activity.

Indications

After an EEG, it is more likely to exclude or confirm the presence of such pathologies in a person as:

• vegetative-vascular dystonia;
• brain inflammation;
• neoplasms;
• epilepsy;
• hypertonic disease;
• nervous disorders;
• cervical osteochondrosis;
• traumatic brain injury.

An electroencephalogram of the brain reflects the state of the organ in the postoperative period, after a stroke, and the dynamics of changes after treatment. It is required when passing a medical examination to obtain a driving category C and D.

How to prepare

You need to prepare for the examination. Tell your doctor if you are taking certain medications. Some of them affect brain activity and should be discontinued 3-4 days before the examination. These medications include anticonvulsants and tranquilizers.

On the eve of the EEG and on the day of the test, you should not consume caffeine-containing products and energy drinks: coffee, tea, chocolate, energy drinks. You can't drink alcohol. These foods have a stimulating effect on the brain, and the brain's encephalogram will be distorted.

It is advisable to eat a few hours before the examination.

It is recommended to wash your hair, but do not apply hairspray, styling foam, or other cosmetics. The fats and other components they contain can worsen the contact of the electrodes with the scalp. Braids and dreadlocks will have to be unbraided, and earrings and jewelry removed.

During the procedure, you need to remain calm and not be nervous. Nothing bad happens, and the procedure is completely harmless.

Carrying out an EEG

Typically, electroencephalography is carried out in a specially equipped room, protected from noise and bright light, in which there is a stationary electroencephalograph. If it is necessary to conduct an EEG on site, mobile devices are used.

The patient is asked to lie down on a couch or sit comfortably in a chair. A helmet or cap with electrodes is placed on the head, the number of which depends on the age of the patient. For a small child, 12 electrodes are enough; for adults, 21 are used. The electrode cavity is filled with a special substance that facilitates the rapid transmission of electrical impulses. Signals coming from the area next to the electrode have the greatest clarity and strength. Signals received from remote areas are weak.

The cap is connected to an encephalograph, which is capable of detecting vibration frequencies of 0.5 - 100 Hz and serves as an amplifier. The electrical signal is amplified by the encephalograph millions of times and transmitted for subsequent processing to a computer. Here, a huge number of signals are converted into a graph - an encephalogram, which is analyzed by the doctor.

The patient must remain calm and not move during the examination. Only at the very beginning may the doctor ask him to blink several times to assess the nature of the technical errors. If the patient urgently needs to change body position or go to the toilet, the study is stopped. In a situation where he made an involuntary movement, moved, the doctor makes an appropriate note so that during further analysis false information does not appear.

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An encephalogram of the brain is recorded for about 15-20 minutes.

EEG with provocative tests

If necessary, after the main recording, provocative tests are done:

1. With hyperventilation - the patient is asked to breathe deeply for several minutes.
2. Test with bright light. It uses a special device capable of reproducing repeating light pulses. An electroencephalogram of the brain records the patient's reaction.
3. Test with an unexpected sound.

Tests help to find out the real cause of the disorder - whether it is a manifestation of a pathological process, mental disorder or simulation. If there is a real pathology, testing may provoke an epileptic attack or convulsion. Therefore, the doctor conducting the diagnosis has the experience and knowledge necessary to provide urgent care. The time required for the sample procedure increases.

EEG with sleep deprivation

If there is a suspicion that a conventional EEG did not provide complete and reliable information, electroencephalography with sleep deprivation is prescribed. Some sources indicate that only in 20-30% of cases, when performed in a standard manner, an encephalogram of the head shows signs of epilepsy. Data obtained during sleep is considered more accurate. Before the study, an adult should not sleep for 18 hours. In some cases, if the examination is carried out in a hospital, the patient is woken up in the middle of the night and forced to undergo diagnostics.

If the patient was able to fall asleep quickly, the procedure takes about an hour. The doctor or nurse makes notes regarding any changes in the patient: flinching, movements of the eyes, arms, legs. In the future, the encephalogram of the brain will be interpreted with their help.

At the end of the procedure, the patient is woken up, his condition is checked and sent home or to the ward. After the diagnosis, rest is recommended.

Features of EEG in children

It is not easy to conduct an EEG of the brain in a small child. He is frightened by a large number of wires, a strange cap, unfamiliar surroundings, people, and devices. It is quite difficult to convince your baby that he will have to lie still for some time. Young children are examined during sleep. Before the study, they need to limit the rest time so that he is tired and wants to sleep before the study. On the day of the examination, babies are woken up 4-6 hours before the usual wake-up time. Children of primary school age - 6-8 hours before, and children over 12 years old are not allowed to fall asleep at all at night.

An electroencephalogram of the brain is a curve obtained by recording fluctuations in the electrical potential of the brain. This research method makes it possible to reflect the mosaic of activity of the cerebral cortex. In a healthy person, it has a certain pattern that corresponds to the harmony of a number of nervous processes. If organic pathology of the brain is observed, this harmony is disrupted.

An EEG electroencephalogram of the brain shows one of the main parameters of the functioning of the nervous system, which is called the property of rhythmicity - it allows us to reflect the consistency of the work of various brain structures. It should be noted that electroencephalographic examinations make it possible to reveal how the brain uses its functional reserves.

Methods for recording EEG electroencephalogram of the brain

• Routine EEG electroencephalogram of the brain– this study begins the diagnosis of paroxysmal conditions. It involves a short-term (10-15 minutes) recording of brain biopotentials. Functional tests are performed - photostimulation and hyperventilation in order to identify hidden changes.
• EEG electroencephalogram of the brain with deprivation or night sleep deprivation– this study is performed with the permission of a doctor if a routine EEG electroencephalogram of the brain turns out to be uninformative. To conduct this study, the patient is woken up two to three hours earlier than usual or not allowed to sleep at all.
• Long-term EEG electroencephalogram of the brain with registration of daytime sleep– it is carried out if paroxysms are suspected or if changes are likely to occur during sleep.
• EEG electroencephalogram of the brain at night– This is the most informative type of research. In this case, a long period of wakefulness before bedtime, napping, night sleep and awakening are recorded. If necessary, an EEG electroencephalogram of the brain is accompanied by video recording and the connection of additional sensors.

Indications for EEG

This study is carried out if:

• the need to assess the degree of functional immaturity of the brain in children;
• sleep disorders;
• paroxysmal manifestations, epileptic or non-epileptic seizures;
• nosological forms accompanied by brain damage;
• vascular diseases of the brain;
• brain tumors;
• traumatic brain injury (brain contusion);
• inflammatory diseases of the brain, consequences of previous neuroinfections or infectious neurotoxicosis;
• diencephalic syndrome;
• consequences of poisoning with neurotoxic poisons;
• neuroses, psychopathy, mental disorders;
• monitoring the effectiveness and dose selection of antiepileptic drugs in comparison with previous studies;
• dysfunctional and degenerative disorders;
• assessment of the depth of anesthesia in case of surgery;
• comatose states;
• confirmation of the diagnosis of brain death;
• hepatic encephalopathy.

Preparing for an EEG

In consultation with your doctor, you must stop taking anticonvulsants three days before performing this procedure. The hair on your head must be clean, you cannot use hairsprays or gels, and your scalp must be free of damage. Braids and dreadlocks should be loosened. Before conducting the study, you need to remove the earrings.

If an EEG electroencephalogram of the brain is performed on a child, he needs to explain what awaits him and convince the child that this procedure is painless. It is advisable to take his favorite toy with you. If the child is scared, you need to first practice at home and try to present this procedure to him in the form of a game. For the study to be successful, the child must be calm. In addition, it should be borne in mind that this procedure is not performed on patients who suffer from a runny nose or cough.

EEG procedure

An EEG electroencephalogram of the brain is a fairly common type of study that allows you to study the state of the brain, reflected in the bioelectrical activity of the brain. An EEG electroencephalogram of the brain shows what electrical activity it has; it is carried out under normal conditions during wakefulness or during sleep. To carry out this procedure, a special cap is placed on the patient’s head. With its help, the doctor installs electrodes - as a rule, children are given 12 electrodes, and adults - 21. EEG electrodes are special devices made of metal or having a special electrically conductive part inside. The electrode is filled with a special electrically conductive substance for contact with the scalp. Using a thin wire, the electrode is connected to a special device - an electroencephalograph, which amplifies the signal from the brain, and then sends it to a computer for processing. The appearance of this signal, which is reflected on the monitor in the form of a curve, allows the doctor to give an opinion about the state of the brain. For example, a specialist can determine the presence of foci of pathological activity - areas of the brain that are not working correctly.

Diagnostic value of EEG

Today, the EEG electroencephalogram of the brain still has more historical significance. This type of research has been replaced by more informative methods - computer, positron emission and magnetic resonance imaging. According to modern diagnostic standards, the EEG electroencephalogram of the brain is valuable as a screening study. In addition, this type of examination is very accessible and does not require a lot of time to carry out. Using an EEG electroencephalogram of the brain, a specialist conducts differential diagnostics. With the help of electroencephalography, it is possible to reveal the reserves of the functional capabilities of the brain.

This type of research is especially informative for epilepsy. This is the first and only method that can be performed in a clinic. Using EEG, electroencephalograms of the brain are used to differentiate between seizures of an epileptic and non-epileptic nature. With the help of such a study, it is possible to identify epileptic foci, monitor the effect of medications, and determine the severity of brain disorders during remission. It is recommended to conduct an EEG electroencephalogram of the brain ten days after the last attack.

Benefits of an EEG

EEG electroencephalogram of the brain at low prices has no effect on humans. This type of study can be performed on patients in a coma. In addition, this is the most optimal method for determining the presence of epilepsy. Electroencephalography also shows the consistency of brain structures.

Features of EEGelectroencephalogram of the brain in children.EEG at competitive prices

EEG electroencephalogram of the brain is a very important method for diagnosing various disorders in brain function. Its undoubted advantage lies in the accessibility and complete painlessness of the procedure. Therefore, if necessary, you should not neglect this research method. We conduct EEG at low prices.

An EEG electroencephalogram of the brain is an integral part of any diagnostic neurological examination, including for conducting a driver’s commission to obtain certificates for the traffic police, obtaining weapons.

Unreasonable headaches, poor sleep, fatigue, irritability - all this can be a consequence of poor blood circulation in the brain or abnormalities in the nervous system. For timely diagnosis of negative disorders in blood vessels, EEG - electroencephalogram of the brain is used. This is the most informative and accessible examination method, which 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 the most accurate, as it shows the complete clinical picture:

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

EEG helps identify signs of epilepsy

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 the examination be done and the price?

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 qualifications of the clinic, as well as the equipment used, prices for the procedure vary significantly.

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

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

Indications for an electroencephalogram

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

The following conditions may be the reason for an EEG:

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

The day before the examination you should not eat chocolate.

How is an electroencephalogram performed?

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

The EEG method takes little time and includes several stages:

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

The importance of the normal functioning of parts of the brain is undeniable - any deviation will certainly affect the health of the entire body, regardless of the person’s age and gender. Therefore, at the slightest signal of a violation, doctors immediately recommend undergoing an examination. Currently, medicine successfully uses a fairly large number of different methods for studying the activity and structure of the brain.

But if it is necessary to find out the quality of the bioelectrical activity of its neurons, then the electroencephalogram (EEG) is clearly considered the most suitable method for this. The doctor performing the procedure must be highly qualified, since, in addition to conducting the study, he will need to correctly read the results. Competent interpretation of the EEG is a guaranteed step towards establishing the correct diagnosis and subsequent prescription of appropriate treatment.

More about the encephalogram

The essence of the examination is to record the electrical activity of neurons in the structural formations of the brain. An electroencephalogram is a kind of recording of neural activity on a special tape using electrodes. The latter are attached to areas of the head and record the activity of a certain area of ​​the brain.

The activity of the human brain is directly determined by the work of its midline formations - the forebrain and the reticular formation (connecting neural complex), which determine the dynamics, rhythm and construction of the EEG. The connecting function of the formation determines the symmetry and relative identity of signals between all brain structures.

The structure of the brain, based on these data, the specialist deciphers the diagnosis

The procedure is prescribed if there are suspicions of various disorders of the structure and activity of the central nervous system (central nervous system) - neuroinfections such as meningitis, encephalitis, poliomyelitis. With these pathologies, the activity of the brain changes, and this can be immediately diagnosed on the EEG, and in addition, the localization of the affected area can be established. An EEG is carried out on the basis of a standard protocol, which records measurements taken while awake or asleep (in infants), as well as using specialized tests.

The main tests include:

• photostimulation - exposure of closed eyes to bright flashes of light;
• hyperventilation - deep, rare breathing for 3-5 minutes;
• opening and closing eyes.

These tests are considered standard and are used for encephalograms of the brain in adults and children of any age, and for various pathologies. There are several additional tests prescribed in individual cases, such as: clenching your fingers into a so-called fist, staying in the dark for 40 minutes, depriving yourself of sleep for a certain period, monitoring night sleep, and passing psychological tests.

These tests are determined by a neurologist and are added to the main tests performed during the examination when the doctor needs to evaluate specific brain functions.

What can be assessed with an EEG?

This type of examination allows you to determine the functioning of parts of the brain in different states of the body - sleep, wakefulness, active physical, mental activity and others. EEG is a simple, absolutely harmless and safe method that does not require disruption of the skin and mucous membrane of the organ.

Currently, it is widely in demand in neurological practice, since it makes it possible to diagnose epilepsy and highly identify inflammatory, degenerative and vascular disorders in the brain. The procedure also provides identification of the specific location of tumors, cystic growths and structural damage as a result of trauma.

EEG using light and sound stimuli makes it possible to distinguish hysterical pathologies from true ones, or to identify simulation of the latter. The procedure has become almost indispensable for intensive care units, providing dynamic monitoring of comatose patients.

The disappearance of eclectic activity signals on the EEG indicates the onset of death

Process of studying the results

The analysis of the results obtained is carried out in parallel during the procedure, and during the recording of indicators, and continues after its completion. When recording, the presence of artifacts is taken into account - mechanical movement of electrodes, electrocardiograms, electromyograms, and induction of mains current fields. The amplitude and frequency are assessed, the most characteristic graphic elements are identified, and their temporal and spatial distribution is determined.

Upon completion, a patho- and physiological interpretation of the materials is made, and on its basis an EEG conclusion is formulated. Upon completion, the main medical form for this procedure is filled out, called a “clinical electroencephalographic report”, compiled by a diagnostician based on the analyzed data from the “raw” recording.

The transcript of the EEG conclusion is formed on the basis of a set of rules and consists of three sections:

• Description of the leading types of activity and graphic elements.
• Conclusion after description with interpreted pathophysiological materials.
• Correlation of indicators of the first two parts with clinical materials.

The main descriptive term in EEG is “activity”, it evaluates any sequence of waves (sharp wave activity, alpha activity, etc.).

Types of human brain activity recorded during EEG recording

The main types of activity that are recorded during the procedure and subsequently subjected to interpretation and further study are wave frequency, amplitude and phase.

Frequency

The indicator is estimated by the number of wave oscillations per second, recorded in numbers, and expressed in a unit of measurement - hertz (Hz). The description indicates the average frequency of the activity being studied. As a rule, 4-5 recording sections with a duration of 1 s are taken, and the number of waves in each time interval is calculated.

Amplitude

This indicator is the range of wave oscillations of the eclectic potential. It is measured by the distance between the peaks of waves in opposite phases and is expressed in microvolts (µV). A calibration signal is used to measure the amplitude. If, for example, a calibration signal at a voltage of 50 µV is determined on a record with a height of 10 mm, then 1 mm will correspond to 5 µV. In deciphering the results, interpretations are given to the most common meanings, completely excluding rare ones.

Phase

The value of this indicator evaluates the current state of the process and determines its vector changes. On the electroencephalogram, some phenomena are assessed by the number of phases they contain. Oscillations are divided into monophasic, biphasic and polyphasic (containing more than two phases).

Rhythms of brain activity

The concept of “rhythm” in the electroencephalogram is considered to be a type of electrical activity related to a certain state of the brain, coordinated by appropriate mechanisms. When deciphering the EEG rhythm indicators of the brain, its frequency corresponding to the state of the brain region, amplitude, and its characteristic changes during functional changes in activity are entered.

Characteristics of brain rhythms depend on whether the subject is awake or asleep

Rhythms of a waking person

Brain activity recorded on the EEG in an adult has several types of rhythms, characterized by certain indicators and states of the body.

• Alpha rhythm. Its frequency remains in the range of 8–14 Hz and is present in most healthy individuals – more than 90%. The highest amplitude values ​​are observed when the subject is at rest, in a dark room with his eyes closed. It is best identified in the occipital region. It is fragmentarily blocked or completely subsides during mental activity or visual attention.
• Beta rhythm. Its wave frequency fluctuates in the range of 13–30 Hz, and the main changes are observed when the subject is active. Pronounced fluctuations can be diagnosed in the frontal lobes under the obligatory condition of active activity, for example, mental or emotional arousal and others. The amplitude of beta oscillations is much less than alpha.
• Gamma rhythm. The oscillation interval is from 30, can reach 120–180 Hz and is characterized by a rather reduced amplitude - less than 10 μV. Exceeding the limit of 15 μV is considered a pathology causing a decrease in intellectual abilities. Rhythm is determined when solving problems and situations that require increased attention and concentration.
• Kappa rhythm. It is characterized by an interval of 8–12 Hz, and is observed in the temporal part of the brain during mental processes by suppressing alpha waves in other areas.
• Lambda rhythm. It has a small range - 4–5 Hz, and is triggered in the occipital region when it is necessary to make visual decisions, for example, when searching for something with open eyes. The vibrations disappear completely after concentrating your gaze on one point.
• Mu rhythm. Defined by the interval 8–13 Hz. It starts in the back of the head, and is best observed in a calm state. Suppressed when starting any activity, not excluding mental activity.

Rhythms in sleep

• Delta rhythm. Characteristic of the deep sleep phase and for comatose patients. It is also recorded when recording signals from areas of the cerebral cortex located on the border with areas affected by oncological processes. Sometimes it can be recorded in children 4–6 years old.
• Theta rhythm. The frequency interval is within 4–8 Hz. These waves are triggered by the hippocampus (information filter) and appear during sleep. Responsible for high-quality assimilation of information and forms the basis of self-learning.
• Sigma rhythm. It has a frequency of 10–16 Hz, and is considered one of the main and noticeable oscillations of the spontaneous electroencephalogram, which occurs during natural sleep at its initial stage.

Based on the results obtained during EEG recording, an indicator is determined that characterizes a complete all-encompassing assessment of the waves - bioelectrical activity of the brain (BEA). The diagnostician checks the EEG parameters - frequency, rhythm and the presence of sharp flashes that provoke characteristic manifestations, and on these grounds makes a final conclusion.

Decoding of electroencephalogram indicators

In order to decipher the EEG and not miss any of the smallest manifestations in the recording, the specialist needs to take into account all the important points that may affect the indicators being studied. These include age, the presence of certain diseases, possible contraindications and other factors.

Upon completion of the collection of all data from the procedure and their processing, the analysis is completed and then a final conclusion is formed, which will be provided for making a further decision on the choice of therapy method. Any disturbance in activity may be a symptom of diseases caused by certain factors.

Alpha rhythm

The normal frequency is determined in the range of 8–13 Hz, and its amplitude does not go beyond 100 μV. Such characteristics indicate a healthy state of a person and the absence of any pathologies. The following are considered violations:

• constant fixation of the alpha rhythm in the frontal lobe;
• exceeding the difference between the hemispheres by up to 35%;
• constant violation of wave sinusoidality;
• presence of frequency dispersion;
• amplitude below 25 μV and above 95 μV.

The presence of disturbances in this indicator indicates a possible asymmetry of the hemispheres, which may be the result of oncological tumors or pathologies of cerebral circulation, for example, stroke or hemorrhage. A high frequency indicates brain damage or TBI (traumatic brain injury).

Stroke or hemorrhage is one of the possible diagnoses for functional changes in the alpha rhythm

A complete absence of the alpha rhythm is often observed in dementia, and in children, deviations from the norm are directly related to mental retardation (MDD). Such a delay in children is evidenced by: disorganization of alpha waves, shift of focus from the occipital region, increased synchrony, short activation reaction, overreaction to intense breathing.

These manifestations can be caused by inhibitory psychopathy, epileptic seizures, and a short reaction is considered one of the primary signs of neurotic disorders.

Beta rhythm

In the accepted norm, these waves are clearly detected in the frontal lobes of the brain with a symmetrical amplitude in the range of 3–5 μV, recorded in both hemispheres. A high amplitude leads doctors to think about the presence of a concussion, and when short spindles appear, to the occurrence of encephalitis. An increase in the frequency and duration of spindles indicates the development of inflammation.

In children, the pathological manifestations of beta oscillations are considered to be a frequency of 15-16 Hz and a high amplitude present - 40-50 µV, and if its localization is the central or anterior part of the brain, then this should alert the doctor. Such characteristics indicate a high probability of delayed development of the baby.

Delta and theta rhythms

An increase in the amplitude of these indicators above 45 μV on a constant basis is characteristic of functional brain disorders. If the indicators are increased in all brain regions, then this may indicate severe dysfunction of the central nervous system.

If a high amplitude of the delta rhythm is detected, a tumor is suspected. Inflated values ​​of the theta and delta rhythm recorded in the occipital region indicate a child’s lethargy and a delay in his development, as well as impaired circulatory function.

Decoding values ​​in different age intervals

An EEG recording of a premature baby at 25–28 gestational weeks looks like a curve in the form of slow flashes of delta and theta rhythms, periodically combined with sharp wave peaks 3–15 seconds long with a decrease in amplitude to 25 μV. In full-term infants, these values ​​are clearly divided into three types of indicators. During wakefulness (with a periodic frequency of 5 Hz and an amplitude of 55–60 Hz), the active phase of sleep (with a stable frequency of 5–7 Hz and a fast low amplitude) and quiet sleep with flashes of delta oscillations at a high amplitude.

Over the course of 3-6 months of a child’s life, the number of theta oscillations is constantly growing, while the delta rhythm, on the contrary, is characterized by a decline. Further, from 7 months to a year, the child develops alpha waves, and delta and theta gradually fade away. Over the next 8 years, the EEG shows a gradual replacement of slow waves with fast ones - alpha and beta oscillations.

Rhythm indicators undergo regular changes depending on age

Until the age of 15, alpha waves predominate, and by the age of 18, the BEA transformation is complete. Over the period from 21 to 50 years, stable indicators remain almost unchanged. And from 50, the next phase of rhythmicity restructuring begins, which is characterized by a decrease in the amplitude of alpha oscillations and an increase in beta and delta.

After 60 years, the frequency also begins to gradually fade, and in a healthy person, manifestations of delta and theta oscillations are noticed on the EEG. According to statistics, age indicators from 1 to 21 years, considered “healthy,” are determined in subjects 1–15 years old, reaching 70%, and in the range of 16–21 – about 80%.

The most common diagnosed pathologies

Thanks to the electroencephalogram, diseases such as epilepsy or various types of traumatic brain injury (TBI) are quite easily diagnosed.

Epilepsy

The study allows you to determine the localization of the pathological area, as well as the specific type of epileptic disease. At the time of a convulsive syndrome, the EEG recording has a number of specific manifestations:

• pointed waves (peaks) - suddenly rising and falling can appear in one or several areas;
• the combination of slow pointed waves during an attack becomes even more pronounced;
• sudden increase in amplitude in the form of flashes.

The use of stimulating artificial signals helps in determining the form of epileptic disease, since they provide visibility of hidden activity that is difficult to diagnose with EEG. For example, intense breathing, requiring hyperventilation, leads to a decrease in the lumen of blood vessels.

Photostimulation is also used, carried out using a strobe (a powerful light source), and if there is no reaction to the stimulus, then most likely there is a pathology associated with the conduction of visual impulses. The appearance of non-standard vibrations indicates pathological changes in the brain. The doctor should not forget that exposure to powerful light can lead to an epileptic seizure.

TBI

If it is necessary to establish a diagnosis of TBI or concussion with all its inherent pathological features, EEG is often used, especially in cases where it is necessary to establish the location of the injury. If the TBI is mild, then the recording will record insignificant deviations from the norm - asymmetry and instability of rhythms.

If the lesion turns out to be serious, then, accordingly, deviations in the EEG will be pronounced. Atypical changes in recordings that worsen over the first 7 days indicate extensive brain damage. Epidural hematomas are most often not accompanied by a special clinical picture; they can only be identified by a slowdown in alpha oscillations.

But subdural hemorrhages look completely different - with them, specific delta waves are formed with bursts of slow oscillations, and at the same time alpha is upset. Even after the disappearance of clinical manifestations, general cerebral pathological changes due to TBI may still be observed on the recording for some time.

Restoration of brain function directly depends on the type and extent of the lesion, as well as its location. In areas exposed to disturbances or injuries, pathological activity may occur, which is dangerous for the development of epilepsy, therefore, in order to avoid complications of injuries, you should regularly undergo an EEG and monitor the status of the indicators.

Regular examination of the brain after TBI will allow timely detection of complications

An encephalogram is a simple way to keep many brain disorders under control.

Despite the fact that EEG is a fairly simple research method that does not require intervention in the patient’s body, it has a fairly high diagnostic ability. Detection of even the smallest disturbances in brain activity ensures a quick decision on the choice of therapy and gives the patient a chance for a productive and healthy life!