Irritation of the cerebral cortex, stem structures

The brain is the most important governing organ of our body. Each of its departments is responsible for the proper functioning of certain organs. Any change in the structure of the brain and its cells leads to disruptions in the functioning of those organs and systems that are under the control of this department. The functioning of the structural elements of the brain is disrupted and their irritation occurs.

Irritation of brain structures is the process of irritation of the superficial (cortex) and deeper structures (stem type of disorders) of the brain. The manifestation of such a pathological condition depends on the location of the process. Irritation of the cerebral cortex is more often observed. This symptom occurs in all age categories of people and its manifestation does not depend on the gender of the person.

Development mechanism

Nerve cells in the brain (neurons) communicate with each other through electrical impulses. They carry out signal transmission from one cell to another. The irritative type of brain abnormalities leads to disruption of impulse transmission and decreased brain activity.

Various head injuries and many other reasons affect the passage of impulses between nerve cells, a decrease in the activity of impulses occurs, and a disorder in the transmission of bioelectric potentials occurs. With a head injury, mixed irritation of the structural elements of the brain can occur.

The result is some disturbances in impulse transmission, but the required treatment for such failures takes years. Only with long-term therapy can normal brain function be restored. Diffuse irritation is diagnosed in cases where it is impossible to determine the exact localization of the irritation process.

Definition of pathology

Irritative disorders arise due to disruption of the transmission of nerve impulses, which provokes a deterioration in brain activity.
Irritation of the cortex covering the brain is a pathological condition that is manifested by the spontaneous appearance of a focus of irritation in a certain area, which leads to the appearance of characteristic symptoms. Spontaneous irritation without obvious reasons is a pathology that significantly complicates a person’s life. Irritation of areas of the brain is not included in the international list of diseases ICD-10, because more often irritation of the cortical, median (deep), diencephalic structures is a symptom of the primary disease.

There are focal (irritation of a local area of the cortex) and diffuse (pathological process spreads throughout the entire cortex) irritation of cortical structures. The pathological condition may be accompanied by specific symptoms or be asymptomatic. Irritation of stem structures, which include the trunk, mediobasal and intermediate sections, leads to dysfunction of the brain and body. Failures manifest themselves in the form of syndromes of neuropsychological and autonomic origin.

Irritation in the area of diencephalic structures, which includes the thalamus, hypothalamus, pituitary gland and other parts of the brain, is a pathological condition, often manifested by decreased self-esteem, sudden mood swings, apathy, and increased fatigue, which indicates behavioral and psycho-emotional disorders.

Causes of irritation symptoms - video

There are several reasons for the development of irritative damage to the cerebral cortex. Firstly, past infectious diseases, the penetration of their pathogens into the brain: the causative agent of rubella, influenza virus, etc. Secondly, diseases associated with metabolic disorders.

Thirdly, pathological conditions affecting normal circulatory function: atherosclerosis, ischemic processes, high intracranial pressure. Benign and malignant neoplasms that exert a compressive effect on brain tissue.

Genetic predisposition. Drug use. Excessive drinking. Psycho-emotional disorders. Environmental factor, unfavorable ecological zone. Industrial hazards. Pregnancy and history of head trauma.

During pregnancy, hormonal changes in the body are observed, so changes are possible that provoke the disease.

What is irritation of the cerebral cortex - symptoms and diagnosis

20.03.2019

A healthy person interacts with the world thanks to irritability (irritation) - the property of the nervous system to respond to environmental stimuli and form a physiological response to it. However, various brain diseases damage nervous tissue, causing irritation in the cortex to appear independently, without external stimuli.

What it is

Irritation of the cerebral cortex is a pathological condition that manifests itself in the form of spontaneous formation of a focus of irritation and excitation in a certain area of the cerebral cortex. Symptoms of irritation are determined by the localization of the pathological condition.

It is necessary to distinguish between normal irritation - irritation of nerve fibers in response to an external stimulus and the formation of an adequate response.

For example, when the eyes are exposed to bright light, the pupil contracts (reduces the flow of photons) as a result of irritation of the optic nerve.

Pathological irritation is a spontaneous irritation that has no obvious origin and leads to a deterioration in the patient’s quality of life.

Irritation is not included in the list of independent diseases; it is not in the International Classification of Diseases, 10th revision. Irritation of the cerebral cortex acts as a manifestation of the underlying pathology, for example, a tumor of subcortical structures.

Irritation can be focal, when irritation is present in a separate area of the cortex (in the visual or frontal) and diffuse (the entire cortex is irritated).

Irritation of the cerebral cortex also occurs:

Asymptomatic - irritation of the cortex may not reach the threshold level and not cause signs of the disease.
Symptomatic - irritation enters the sensitivity threshold and determines the clinical picture.

Causes

Pathological irritation of the cerebral cortex has the following causes:

Inflammatory diseases of the nervous system: neurosyphilis, herpetic encephalitis, meningitis.
Complications of major diseases: malaria, rubella, measles, meningococcal encephalitis.
Circulatory disorders in the brain: atherosclerosis, transient ischemic attack, embolism.
Violation of intracranial pressure due to a tumor.
Traumatic brain injuries: concussion, bruise.
Dislocation syndrome.
Bad habits.
Working and living in polluted conditions.

Symptoms

Signs of cortical irritation are determined by the localization of irritation. Symptoms are directly related to the area of the cortex where focal spontaneous irritation occurs:

Frontal zone. Accompanied by the occurrence of motor reactions. Muscle contraction depends on the location of stimulation in the precentral frontal gyrus. After irritation of the frontal area, complex motor patterns may appear: the patient will begin to tie his shoelaces in the air.
Temple area. Simple auditory hallucinations (acoasms) and complex hallucinations appear, accompanied by a voice commenting on the content.
Occipital zone. Accompanied by simple (photopsia) and complex visual hallucinations. Photopsia are second-long hallucinations: flashes of light, a small spot. Complex hallucinations consist of images, the content of which is determined by the patient’s inner mental life.
The parietal zone is an area of general sensitivity. Tingling, numbness, and crawling sensations occur in different parts of the body. Irritation in this area is also accompanied by perverted sensations of touch, pain, heat or cold.

Diffuse irritation of the cortex is accompanied by small (petit mal) and large (grand mal) convulsions.

Petite seizures include myoclonic spasms of individual muscles. Muscle contraction is characterized by rhythm and absence of complications. Petit mal also manifests itself as absence seizures – short-term loss of consciousness while maintaining muscle tone throughout the body. After 20-30 seconds of “switching off”, patients come to their senses and continue their work. They don't know that they just came out of consciousness.

Grand mal consists of several successive stages:

Harbingers. The day before extensive seizures, people feel unwell and have a headache. They don't sleep well.
Aura. Within 30-40 minutes, patients complain of vague pain in the abdomen, arm or heart.
Tonic phase. The man loses consciousness and falls. All the muscles of the body contract simultaneously and synchronously. Skin color turns blue, breathing is uneven. Duration – no more than 60 seconds.
Clonic phase. All muscles of the body contract unevenly, asynchronously, chaotically: each muscle contracts separately. Lasts 1-2 minutes.

In general, the entire grand mal seizure lasts up to 3 minutes. After the last phase, the muscles relax and the patient goes into deep sleep. After waking up, he experiences disorientation and retrograde amnesia (he does not remember what happened before the seizure).

Clinical symptoms

Irritation of the cortical sections manifests itself in different symptoms, the structure of the cortex is complex and each part has a specific purpose. Let's take a closer look at the signs of irritation of each lobe of the cerebral cortex.

Irritative changes in the posterior segment of the middle frontal gyrus:

Initially, the patient experiences eye twitching.
Then the whole head begins to tremble.
Patients begin to have seizures with convulsions.

Irritation of the posterior part of the superior frontal gyrus:

Unexpected convulsions occur, covering the entire opposite muscle structure of the torso.
At the same time, the patient is overtaken by cramps of the limbs, turning of the eyes and head, which cannot be controlled.
At the onset of a seizure, patients become unconscious.

Symptoms of irritation of the anterior central gyrus appear:

Convulsive attacks. Convulsions affect large muscle groups.
The onset of convulsions from the finger and facial muscles is noted.

Irritation of the parts located below the central gyrus (opercular region) causes the following symptoms to appear::

Uncontrolled contractions of muscles regulated by chewing and swallowing (uncontrolled slurping, chewing, etc.).
Generalized cramps may occur, affecting all muscle groups.

Convulsions that occur due to damage to the above departments occur spontaneously, without any “precursors”.

Irritative changes in the following parts of the cortical area are accompanied by convulsions, starting with an aura (precursors) signaling an upcoming convulsion.

Irritative lesions of the posterior central gyrus are identified by the following signs:

Epileptic seizures develop.
There is a sensitivity disorder in the form of an attack of parasthesia, a burning sensation, tingling sensation suddenly occurs on the opposite side. The spread of the process leads to the fact that convulsions also affect nearby areas of the body.

Localization of irritative changes in the posterior adversus is characterized by the following clinical manifestations. A very strong convulsion occurs across the entire opposite half of the body.

Affection of the occipital lobe can be suspected by the following signs:

The perception of the world is disrupted, hallucinatory distortion.
Pathological turning of the head and eyes in the opposite direction, the process is not controlled.
Then a grand mal seizure occurs.

Signs of disorders of the mediobasal formations of the temporal region are manifested by serious functional disorders. The occurrence of irritative changes in the temporal gyrus causes a serious distortion of auditory perception (hallucinations), it is a harbinger of a convulsion attack.

Irritative disorders of the inner side of the temporal lobe occur with an aura in the form of changes and distortion of the sense of smell (olfactory hallucinations). Then comes the attack.

These two cases do not always result in a major attack of epilepsy. They are characterized by the onset of a minor attack of epilepsy following an aura. This condition is characterized by loss of consciousness for a short time or clouding of consciousness.

Sometimes, when one or another part of the temporal lobe of the cortex is irritated after sensitive auras, patients seem to be immersed in an unreal world in which everything is familiar and passed through, experienced.

In addition to the listed pathological changes, a diencephalic type of destruction can occur, in which the work of the median stem structures is disrupted. Such disorders are also accompanied by seizures and various types of disorders:

Disruption of the autonomic nervous system (panic attacks, etc.).
Impaired cognitive functions (changes in speech, mental performance, etc.).
Unstable emotional background.

Irritation of the brain, signs and causes – Neurology

Irritation of diencephalic structures of the brain: signs

Irritation of diencephalic structures of the brain is a neurological term that characterizes a number of disorders caused by irritation of parts of the brain. Depending on which part of the brain is affected, different symptoms may occur.

Diffuse changes in biopotentials and their symptoms

Disorders may occur in the brain and its individual parts, resulting in the development of autonomic, psychopathological and neuropsychological disorders. Irritation of the cerebral cortex and its parts is an irritation that occurs as a result of infectious processes, neoplasms, circulatory or metabolic disorders.

Signals are transmitted between neurons in the brain. This process is carried out using electrical impulses. When signal transmission is disrupted, it negatively affects the entire human body. At the same time, the bioelectrical activity of the brain deteriorates.

The presence of these failures can be determined using instrumental diagnostic methods. Disturbances in the bioelectrical activity of the brain indicate the development of pathological processes.

As a result of traumatic brain injury and under the influence of other factors, the activity of electrical impulses through which neurons transmit signals to each other decreases. This is called disorganization of bioelectrical activity.

As a result of injuries, diffuse irritation of the brain may occur. These are mild disorders that lead to minor disruptions in the transmission of impulses. If treatment is carried out, then within several months or years the condition of the stem structures of the meninges can be restored. Diffuse changes are spoken of when local disturbances cannot be detected.

Such deviations can manifest themselves as mood swings, fatigue, and discomfort.

Brain activity can be disrupted in different parts. When the cerebral cortex is damaged, epilepsy attacks and other disorders appear, which depend on the area of damage:

If general cerebral disturbances of an irritative nature are observed behind the middle frontal part, then the head begins to twitch first, and gradually the symptom spreads to the whole body.
When the adversive field is damaged, seizures appear on the side of the body opposite the irritated side of the brain. At the beginning of the attack, the patient may lose consciousness.
Irritation of the opercular zone is accompanied by loss of control over chewing, slurping and swallowing movements.
If the central gyrus is affected, the patient is bothered by epileptic seizures, the onset of which is observed on the face and limbs.
An irritated posterior central gyrus is accompanied by numbness and tingling in half the body.
When the occipital lobe is damaged, hallucinations appear, the head and eyes turn in the opposite direction, and a widespread seizure develops.
The process of irritation in the cranial fossa causes trigeminal neuralgia, problems with hearing and vision, loss of smell, and changes in the sensitivity of the facial muscles.

Source: https://perinatal39.ru/infektsionnye-zabolevaniya/irritatsiya-golovnogo-mozga-priznaki-i-prichiny.html

Diagnostics

To clarify the disorders that have arisen, several instrumental diagnostic methods are prescribed:

Encephalogram. This procedure measures the exact electrical activity of the brain. In this way, extensive diffuse irritation is revealed.
Magnetic resonance imaging.
Careful collection of anamnesis, determining the presence of predisposing factors.

Signs in childhood

During childhood development, it is difficult to identify DSS. Sometimes children are more restless than others and suffer from jet lag (sleep and wakefulness). Infants may have problems with breastfeeding and causeless crying.

During the developmental period, these children, as a rule, become more mobile and more often suffer from injuries. They may experience a “displacement” of development or skip one of the stages of verticalization (most often crawling), and an inability to concentrate on the game. Increased agitation and clumsiness may appear.

Also worth paying attention to are the first emotional outbursts of the nature of anger and aggression. Although these manifestations are nonspecific, often observed in other children at a certain period of development, with brain dysfunction they seem unusually expressive.

A common manifestation is delayed speech development, general slow or uneven development. Sometimes children are superior to their classmates in some school subjects (for example, in mathematics), while in others they show below average success (for example, their native language).

General impairment of cognitive functions is observed with damage to the basal cholinergic system.

Dysfunction of the midline structures of the brain is characterized by a wide range of symptoms. In particular, children of preschool and school age exhibit:

movement disorders;
emotional and behavioral disorders;
impaired concentration and memory;
disorders of speech, perception and thinking.

Disorders in the motor area consist of a failure in the process of arousal and calm (hyperactivity, hypoactivity). It is also manifested by increased fatigue, but an inadequate reaction (a restless child becomes even more hyperactive, a calm child is more prone to hypoactivity). But both forms are accompanied by increased irritability.

One of the signs of dysfunction of the midbrain system is a violation of gross and fine motor skills, manifested in general motor or graphomotor inefficiency.

Manifestations of improper functioning of the upper-stem and lower-stem systems include emotional disorders. Emotional lability is manifested by changes in mood, tendency to affectivity and aggressiveness.

Children with brain dysfunction often act impulsively - they immediately do what they want at the moment, without thinking about the consequences of their actions. They also have a low tolerance for frustration - some stimuli can lead to an affective explosion. Although these children are very sensitive and sometimes hypersensitive, they have difficulty empathizing with other people's feelings. They often hurt others without realizing it.

Since such children are often ignored by others due to inappropriate behavior, they try to attract attention to themselves. But they do it in an inadequate way - they scream, “explode”, thus closing a circle around themselves.

Children with attention deficits are often distracted and cannot focus. Their activity is easily interrupted by any stimulus. They often forget not only instructions, but also their things and lose them. Often they do not remember where and why they went, what they wanted to do.

Speech, perception and thinking disorders manifest themselves in slow speech development with defects in pronunciation (dyslalia). Speech motor disorder is associated with difficulty pronouncing longer, more complex words. Poor vocabulary is reflected by thinking disorders, because thinking is closely related to speech.

The above symptoms do not appear in every child with impaired brain function. The degree of their severity also varies. Many signs weaken with maturation of the central nervous system.

Treatment

Treatment measures first begin with eliminating the etiological factors leading to the development of the disorder. That is, some kind of prevention must be carried out. In cases of injury, chemical poisoning, or radiation, the cause is more difficult to eliminate, but maintaining a healthy lifestyle can prevent severe disorders.

Atherosclerosis is the primary cause, so proper nutrition and a healthy regimen are the first aides in treatment. Therapeutic measures for irritation are aimed at:

Improvement and strengthening of vascular walls.
Prevention of blood clots and blood thickening.
Reducing blood cholesterol.
Normalization of the state of the vascular endothelium.

Taking into account the above points, patients will be prescribed the following groups of drugs:

Fibric acid derivatives: Miscleron, Atromid, etc. They improve metabolism in the body.
Statins are prescribed along with fibrates. They lower blood cholesterol levels by reducing its production in the body.
Derivatives of nicotinic acid. They improve cerebral and peripheral blood circulation and prevent platelet aggregation
Bile acid sequestrants. They reduce the level of “bad” cholesterol in the blood.

In cases of malignant neoplasms and other serious causes of irritation, symptomatic therapy is carried out and the main cause of the disease is eliminated.

After a course of treatment with medications, further rehabilitation therapy in the form of psychological procedures is required. Successful treatment is expected in cases where the lesion is detected in the early stages, before it has become widespread throughout the brain.

Irritation of parts of the cerebral cortex can cause unpleasant, serious consequences of various types for the body as a whole. It is impossible to predict such a process, but some preventive measures can prevent disruption of brain activity.

What is irritation of the cerebral cortex

› Diseases

Irritation of the cortex covering the deep structures of the brain is a natural process that normally occurs as a result of exposure to external factors, which forces the central nervous system to react and form a physiological response.

Pathologies of nervous structures provoke disturbances in the functioning of the brain, which is reflected in irritation (irritation) of its parts without the influence of external stimuli. This condition leads to malfunctions in all body systems.

Diagnosed at any age, regardless of the person’s gender.

Definition of pathology

Irritative disorders arise due to disruption of the transmission of nerve impulses, which provokes a deterioration in brain activity.

Irritation of the cortex covering the brain is a pathological condition that is manifested by the spontaneous appearance of a focus of irritation in a certain area, which leads to the appearance of characteristic symptoms.

An example of a normal reaction of the nervous system to an external irritant is a decrease in pupil diameter in response to bright light, which occurs as a result of irritation of the optic nerve.

Spontaneous irritation without obvious reasons is a pathology that significantly complicates a person’s life.

Irritation of areas of the brain is not included in the international list of diseases ICD-10, because more often irritation of the cortical, median (deep), diencephalic structures is a symptom of the primary disease.

Among the pathologies manifested by similar symptoms, it is worth noting a tumor localized in the brain tissue, organic damage to the nervous tissue of various etiologies.

There are focal (irritation of a local area of the cortex) and diffuse (pathological process spreads throughout the entire cortex) irritation of cortical structures.

The pathological condition may be accompanied by specific symptoms or be asymptomatic.

Irritation of stem structures, which include the trunk, mediobasal and intermediate sections, leads to dysfunction of the brain and body. Failures manifest themselves in the form of syndromes of neuropsychological and autonomic origin.

Irritation in the area of diencephalic structures, which includes the thalamus, hypothalamus, pituitary gland and other parts of the brain, is a pathological condition, often manifested by decreased self-esteem, sudden mood swings, apathy, and increased fatigue, which indicates behavioral and psycho-emotional disorders.

Causes

The pathological condition can develop as a complication of somatic diseases - measles, chickenpox, rubella, malaria. Such disorders can be provoked by an increase in intracranial pressure due to various reasons. Reasons for irritative changes include:

Traumatic brain injuries.
Infectious diseases affecting parts of the brain (meningitis, encephalitis, abscess, arachnoiditis).
Tumor processes and other space-occupying formations in the cranial cavity (cysts, foci of hemorrhage).
Demyelinating diseases, including multiple sclerosis.
Lesions of the vascular system supplying brain tissue (atherosclerosis, TIA - transient cerebrovascular accident, embolism - blockage of a vessel, ischemic, hemorrhagic strokes).
Neurodegenerative diseases.
Violation of metabolic processes.
Intoxications occurring in acute and chronic forms (chronic alcoholism, chemical poisoning).

Among the provoking factors, it is worth noting alcohol abuse, drug use, stress, excessive mental, mental, physical stress, living in a region with an unfavorable environment. Often, such disorders occur during pregnancy, as a consequence of hormonal changes against the background of existing organic brain damage.

Main features

Dysfunction of the middle (deep) sections is often manifested by attacks of general weakness, a feeling of suffocation, dizziness, malaise, unmotivated fear, changes in pulse and blood pressure.

These symptoms are similar to those of epilepsy and reflect the process of irritation of brain structures. Irritation of the cortical parts is more often manifested by behavioral deviations without pronounced neurological symptoms.

Symptoms caused by the disorder depend on the location of the source of irritation:

Frontal zone. Manifestations: motor dysfunction, twitching of the head and visual organs. When the adversive field is damaged, convulsions occur, often with confusion and loss of consciousness at the beginning of the attack.
Temporal zone. Accompanied by auditory hallucinations. Damage to the opercular region initiates involuntary swallowing and chewing movements.
Occipital zone. Manifestations: visual hallucinations, photopsia - the appearance of foreign objects in the field of view (dots, lightning, spots, lines).
Parietal zone. It manifests itself as a sensitivity disorder - numbness, tingling, impaired perception of cold and hot objects, a change in the pain threshold. Damage to the central gyrus area is accompanied by epileptic seizures, which at the initial stage affect the muscles of the face and limbs.
Cranial fossae. Manifestations: visual and auditory dysfunction, trigeminal neuralgia (affecting the trigeminal nerve), olfactory disorder.

Signs of cortical irritation with diffuse damage to multiple areas of the brain include convulsive syndrome.

Convulsions develop according to the myoclonic type, regardless of the state (rest, movement) in which the patient is. Cortical myoclonus is characterized by a short-term, rapid course.

At the same time, absence seizures—minor epileptic seizures—may occur while maintaining normal muscle tone. Grand mal epileptic seizures develop according to the following scheme:

Aura. Headache, sleep disturbance, feeling unwell several hours or days before the attack.
Phase of increased muscle tone. Loss of consciousness and balance. Synchronous, simultaneous contraction of muscles in the entire body. Duration – about 60 seconds.
Clonus phase. Unsynchronous, chaotic contraction of body muscles. Duration – about 2 minutes.

After a seizure, the muscles relax and the patient falls into deep sleep. Upon awakening, the patient is often disoriented regarding space and time. He may have retrograde amnesia (cannot remember events preceding the attack).

Signs of irritation in the area of diencephalic (deep) structures that make up the brain include epileptic seizures, deterioration of cognitive abilities, speech dysfunction, disorders of the autonomic nervous system, and psycho-emotional disorders.

Irritation in the area of the stem structures at the bottom of the cranium is accompanied by such disorders as confusion, disturbance of sleep and wakefulness, deterioration of memory and concentration. Irritation of the hypothalamic structures that make up the central parts of the brain is accompanied by the following symptoms:

Malfunctions of the autonomic nervous system.
Depressive state.
Deterioration of attention and memory functions.
Psychopathic disorders with symptoms characteristic of Korsakoff psychosis (retrograde amnesia, ataxia, disorientation, behavioral disorders).

Irritation in the area of the hypothalamic regions often initiates a deterioration in cognitive abilities, reversible speech dysfunction, and a change in personal perception of the position of parts of the torso and the entire body in space.

Treatment options

Treatment of the pathological condition, which is manifested by general cerebral changes of an irritative nature, is aimed at eliminating its causes. Treatment is carried out for the primary disease that provoked the corresponding symptoms. In case of infection, antibacterial and antiviral drugs are prescribed. Other medicines:

Nootropic, stimulating cellular metabolism in nervous tissue, protecting neurons from damage.
Regulating cerebral blood flow, improving the rheological properties of blood.
Antidepressants, sedatives.

The therapy program involves taking medications that strengthen the vascular wall, regulate cholesterol levels and lipid metabolism, and prevent the formation of blood clots.

The patient should avoid head injuries and excessive physical and mental stress.

Therapeutic measures include neurocorrection - procedures during which brain functions are redistributed and compensatory mechanisms are activated.

Irritation (irritation) of brain structures leads to behavioral disorders and neurological symptoms, which deteriorates the patient’s quality of life. The pathological condition is a consequence of a primary disease, which is identified during a diagnostic examination and is treated first. What is irritation of the cerebral cortex Link to main publication

Source: https://golovmozg.ru/zabolevaniya/irritatsiya-kory-golovnogo-mozga

Diffuse changes in bioelectrical activity of the brain on EEG

93 years have passed since Hans Berger introduced the electroencephalogram (EEG) into clinical practice.
EEG is an important diagnostic tool for studying neurological disorders of various etiologies. Diffuse EEG changes are disturbances in the bioelectrical activity of the brain (BEAGM) caused by generalized encephalopathy. There are several types of generalized changes in BEAGM:

Diffuse slowing.
Periodic diffuse epileptiform discharges (PLEDs).
Flash-suppression pattern.
Patterns of coma.
Triphasic waves.

Electroencephalography is widely used in the practice of neurologists.

Diffuse slowing of bioelectrical activity of the brain is divided into 3 types in neurology:

mild diffuse changes in EEG activity;
transient slowdown;
continuous deceleration.

With mild diffuse changes in the EEG, occipital dominant alpha activity is present, but the wave frequency is less than 7 Hz. The lower limit of normal for adults is usually considered to be 8 Hz. The lower limits of normal for a child aged 1-3-5-8 years are 5-6-7-8 Hz.

Moderate diffuse EEG changes are manifested by paroxysms (“bursts”) of generalized slowing and polymorphic delta waves. Paroxysms occur less frequently, which are located in the frequency range of theta waves, and sometimes they are rhythmic rather than polymorphic.

If the waves are rhythmic, this type of transient slowing is called frontal intermittent rhythmic delta activity (FIRDA). In this case, occipital dominant alpha activity is present; it may be normal or slow in frequency.

EEG changes may be nonspecific, but some are associated with specific diseases

Polymorphic delta activity (PDA) is recorded in 80% of the entire EEG recording during continuous slowing of the BEAGM. Occipital dominant alpha activity is usually absent.

With generalized continuous slowing, the EEG recording is dominated by cerebral polymorphic delta activity. Continuous deceleration (more than 80% of the entire recording) is accompanied by severe generalized encephalopathy. Most often it is caused by metabolic or systemic disorders of the brain.

The 3 types of deceleration described above represent the 3 degrees of severity (mild, moderate and severe) of diffuse encephalopathy. They can be caused by various reasons and are most often observed in metabolic or toxic (including drug-induced) encephalopathies.

However, the most slowly progressing neurodegenerative diseases (for example, Alzheimer's disease) do not show pronounced signs on the EEG in the early stages.

Minor cerebral changes appear in mental disorders. Irritative changes in EEG activity may indicate the presence of a tumor or drug-induced encephalopathy.

Electrical discharges in this type of generalized changes in BEAGM occur at regular intervals. The discharges are multiphase and have an epileptiform morphology. Thus, they are similar to periodic lateral epileptiform discharges (PLEDs), except that they have a generalized rather than lateral distribution.

They are sometimes called generalized periodic epileptiform discharges (GPED). In contrast, the term bi-PLED generally refers to periodic discharges that are asynchronous.

Moderate regulatory changes in the EEG are characterized by a burst of activity (a mixture of sharp and slow waves), periodically alternating with episodes of inhibition (activity

Bioelectrical activity is literally the electrical vibrations of the brain. The neurons that create a huge network in it have their own electrical wave. These waves are recorded by EEG, and the data obtained through the study can tell a lot about the state of health and psyche of an individual.

Biowaves (or rhythms of brain activity) are divided depending on amplitude and frequency:

beta waves – 14-40 Hertz, amplitude – up to 20 µV;
alpha - 8-13 Hz, wave amplitude - 5-100 µV;
gamma - above 30 Hz, occasionally up to 100 Hz, amplitude - up to 15 μV;
delta - 1-4 Hz, amplitude - 20-200 µV.

There are other, less studied waves; we have listed only the main ones. And what happens if during the study mild diffuse changes in the bioelectrical activity of the brain are detected? We will now look at this issue.