Brain defects in newborns. Congenital defects, anomalies, defects in brain development

Ministry of Education and Science of the Russian Federation

Federal Agency for Education

State Educational Institution of Higher Professional Education "Altai State University"

Faculty of Psychology and Philosophy

Department of General and Applied Psychology

Subject: Brain malformations

Test on the subject: Anatomy of the central nervous

human systems

Performed:

student gr. 1881

correspondence department of the FPF

Shmakova Olga Sergeevna

Checked:

Ph.D., Associate Professor

Grechishnikova Lyudmila Mikhailovna

Introduction

2.1 Congenital hydrocephalus

2.2 Craniostenosis

2.3 Agenesis of the corpus callosum

2.4 Anterior hernias

2.5 Congenital intracranial aneurysms

Final part

Bibliography

Introduction

Anomalies in the development of the nervous system can be divided into those combined with recognizable somatic defects and those limited only by the nervous system (damage to the nervous system occurs in 60% of the total). It is also advisable to classify developmental anomalies and congenital defects into a group caused by acquired or external factors, and into a genetically determined group. However, in some cases they are based on a complex interaction of genetic factors and environmental conditions.

Factors influencing the development of the nervous system:

The adverse effect of any factors on the brain during its development is a complex derivative of the severity of the damage, its duration, the specific biological effect of the harmful agent and the specific stage of development during which this effect occurs. It is especially important to know the causes of anomalies associated with environmental influences, since they can be eliminated.

Toxins present in the mother's body may cause damage to the developing brain and nerves. Fetal alcohol syndrome. a significant cause of mental retardation is due to the effect on the fetus of excessive amounts of alcohol consumed by the mother. In addition, maternal use of medications, especially anticonvulsants, can affect the development of the fetal brain. Trimethadione causes severe abnormalities in the fetus. It has been established that valproic acid can lead to the formation of spinabfida. Maternal use of phenytoin in the early months of pregnancy causes minor but clearly recognizable effects on brain formation and somatic development. Isotretinoin, a drug used for acne, has been linked to birth defects of the brain. Defects in brain development in fetuses from Minimata Bay, Japan, were found to be caused by exposure to an organic mercury toxin. The occurrence of microcephaly and mental retardation can be caused by radiation and radiomimetic factors affecting a woman in the first trimester of pregnancy.

I. Classification of malformations of internal organs

The term “congenital malformation” should be understood as persistent morphological changes in an organ or the entire organism that go beyond variations in their structure.

Congenital malformations occur in utero as a result of disruption of the developmental processes of the embryo or (much less often) after the birth of the child, as a consequence of disruption of the further formation of organs.

The terms “congenital anomalies”, “congenital defects” and “developmental defects”, “developmental anomalies” can be used as synonyms for the term “congenital malformations”.

The concept of “congenital defect” is not limited to developmental disorders, but also includes inborn errors of metabolism.

Congenital defects should not include postnatal disturbances in the proportions or sizes of organs that are a manifestation of endocrine disorders (pituitary dwarfism, gigantism, acromegaly).

All malformations of internal organs can be divided into 4 groups:

Quantity anomalies:

A) Absence of an organ due to agenesis or aplasia.

1) Agenesis- nondevelopment of an organ, depending on the absence of its anlage in the embryo.

2) Aplasia- nondevelopment of the embryonic rudiment, expressed, like agenesis, in the congenital absence of an organ.

B) Organ doubling (duplication) or the formation of additional organs is caused by multiple embryonic anlages or division of the organ rudiment.

IN) Fusion (non-separation) of organs.

Position anomalies:

A) Heterotopia- the laying of an organ in the embryo in an unusual place, in which its further development occurs.

B) Dystopia- displacement of an organ to an unusual place in the embryonic period.

B) Inversion- reverse position of the organ relative to its own axis or the median plane of the body due to a violation of embryonic rotation.

Anomalies in shape and size:

A) Hypoplasia- insufficient development of an organ due to a delay at any stage of embryogenesis, manifested by a deficiency in the relative mass or size of the organ, exceeding a deviation of two sigma from the average for a given age. The hypoplastic organ is reduced in size, its function is reduced or completely absent.

1) Simple hypoplasia- is not accompanied by a violation of the structure of organs.

2) Dysplastic hypoplasia- accompanied by a violation of the structure of organs.

B) Hyperplasia (hypertrophy)- an increase in the relative mass or size of an organ due to an increase in the number (hyperplasia) or volume (hypertrophy) of cells.

B) Fusion of paired organs- depends on the fusion of their anlages in the embryonic period.

Anomalies of structure (structure):

A) Atresia- complete absence of a canal or natural opening of the body.

B) Heteroplasia- impaired differentiation of certain tissue types.

B) Diverticulum- abnormal growth of hollow organs.

D) Dysplasia- violation of the formation of the constituent tissue elements of the organ.

D) Stenosis- narrowing of the canal or opening.

E) Hamartia- incorrect ratio of tissues in anatomical structures or the presence of normally absent remains of embryonic formations in a mature organism.

G) Dysontogenetic cyst.

In addition, there may be abiotrophy- a hidden anomaly of an organ or system of the body, characterized by a sharp decrease in adaptive capabilities and manifested by premature weakening of function at the usual level of activity.

Based on etiology, there are 3 groups of defects:

Hereditary - defects that arise as a result of mutations, that is, persistent changes in hereditary structures in germ cells (gametes) - gametic mutations, or zygotic mutations in the zygote.

Exogenous - defects caused by damage to the embryo or fetus directly by teratogenic factors. Because malformations caused by teratogens can copy genetically determined malformations, they are often called phenocopies.

Multifactorial - defects that occurred from the combined influence of genetic and exogenous factors, and none of them separately is the cause of the defect.

Depending on the object of exposure to harmful factors, congenital defects can be divided into defects resulting from:

1) gametopathies,

2) blastopathies,

3) embryopathies,

4) fetopathies.

1. Gametopathies- damage to germ cells, “gametes”.

2. Blastopathy- damage to the blastocyst, that is, the embryo in the first 15 days after fertilization (until the differentiation of the germ layers is completed and the uteroplacental circulation begins).

3. Embryopathies- defects resulting from damage to the embryo, regardless of etiology, in the period from the 16th day after fertilization to the end of the 8th week.

4. Fetopathies- damage to the fetus in the period from the 9th week until the end of labor. Defects in this group are relatively rare.

Based on their prevalence in the body, congenital malformations are divided into 3 groups:

1. Isolated - localized in one organ.

2. Systemic - within one organ system.

3. Multiple - localized in the organs of two or more systems.

Congenital malformations of the central nervous system rank first in frequency among other defects, occurring in 30% of cases among developmental defects found in children.

Etiology and pathogenesis. Of the exogenous factors, the importance of the rubella virus, human immunodeficiency, herpes simplex has been precisely established; the influence of cytomegaly viruses, Coxsackie viruses, drugs (quinine, hydantoin, etc.), alcohol, radiation energy, and hypoxia is assumed. Gene mutations are of undoubted importance; in chromosomal diseases, among multiple defects, they occur almost as a rule. The development of the defect is associated with exposure to a damaging agent throughout the entire embryonic period, including the early fetal period. The most severe defects occur when damage occurs at the beginning of the neural tube (3-4 weeks of intrauterine life.

II. Brain malformations

Brain (encephalon) - the anterior section of the central nervous system with its surrounding membranes is located in the cavity of the cerebral part of the skull. The upper convex surface of the brain corresponds in its shape to the inner surface of the cranial vault, and the lower, flatter, with complex relief, corresponds to the inner base of the skull.

The weight of the adult human brain ranges from 1100 to 2000 g; in men, on average, it is about 1394 g, and in women, 1245 g. After 60 years, the mass and volume of the brain decrease slightly.

The most common causes of various malformations of the brain are incorrect formation of the nervous system or damage to it during embryonic development due to changes in genetic information (disorders of histogenesis and cytoarchitectonics of the brain) or the influence of external factors, some infections suffered by the mother during pregnancy (toxoplasmosis, rubella , cytomegaly, viral hepatitis), exposure to ionizing radiation, trauma, and also as a result of the harmful effects of certain chemicals. Malformations of the brain (except for cerebral hernias), as a rule, are accompanied by mental retardation.

The method can be used in medicine, in particular in neurosurgery and neurology. Direct response to light is examined. Watch the pupil. If it narrows, and after this the pupil begins to gradually expand, then this indicates a pathology in the midbrain. The method allows to increase the accuracy of topical diagnostics.

The invention relates to the field of medicine, in particular neurosurgery and neurology, and can be used to determine pathology in the midbrain in children during a period when damage to the midbrain is minimal and other symptoms may not be detected. There is a known method for determining pathology in the midbrain (Badalyan L. O. “Children’s Neurology.” M.: Medicine., 1984, p. 136), which we adopted as a prototype, in which the patient is seated so that the face is turned to the source light, and suggest fixing your gaze on a distant point. The researcher covers both eyes of the patient with his palms, which leads to dilation of the pupils. Then he quickly withdraws one hand and observes the direct reaction of the pupil to the light. The pupil narrows, which indicates the absence of pathology in the midbrain. Violation of the reaction of the pupils to light indicates pathology in the midbrain. However, with minimal damage to the midbrain, there may be no disturbance in the reaction of the pupils to light. The invention is aimed at creating a method for determining pathology in the midbrain, which makes it possible to increase the accuracy of topical diagnostics. The essence of the method is to study the direct reaction of the pupils to light, and when the pupils dilate after they constrict, pathology in the midbrain is determined. The direct reaction of the pupils to light is carried out by a reflex arc, which consists of an afferent (sensitive) path and an efferent (motor) path. The sensory pathway is the optic nerve, the motor pathway is the oculomotor nerve. They connect at the level of the midbrain, namely in the quadrigeminal region, more precisely in the anterior colliculus, where impulses from the optic nerve pass through the intercalary cells of the quadrigeminal region to the oculomotor nerve. The reaction of the pupils to light can occur with normal function of the above pathways. Even with minimal pathology in the midbrain, the reaction of the pupils is impaired. The inventive method differs from the prototype in that if, after constriction of the pupil, it dilates, pathology in the midbrain is determined. The method is carried out as follows. The patient is seated facing the light source and asked to fix his gaze on a distant point. Then they cover the patient’s eyes with their palms and withdraw one hand with a sharp movement, while observing the pupil - it narrows. If after this the pupil begins to dilate, then this indicates a pathology in the midbrain. The proposed method for determining pathology in the midbrain in children was developed and passed clinical trials at the Russian Research Neurosurgical Institute named after. prof. A. L. Polenov in 21 patients. We give examples - two extracts from the medical history. Example 1 Patient A, 14 years old (case history no. 1151-97), was admitted to the institute on 2/12-97 with complaints of decreased sensitivity and weakness in the left limbs. She became ill in February 1997, when numbness occurred in her left thigh, which lasted for several seconds. The attacks of numbness began to recur. In March, numbness affected the entire left leg, and after a while the left arm. At the end of June, the left leg became weak, and in mid-July, the left arm also weakened. In August, horizontal double vision appeared. Objectively: the condition is satisfactory. The right palpebral fissure is narrower than the left; when looking to the right, a horizontal small-sweeping nystagmus of one right eye is revealed. The pupils are wide, the direct reaction of the pupils to light is lively. After constriction, the pupils gradually dilate. Left-sided hemiparesis is detected. Diffuse atrophy of the muscles of the left leg, the left foot is smaller than the right. The hand and forearm of the left hand are thinner than the right. Deep reflexes on the left extremities are higher, pathological reflexes of Babinsky and Model-Bekhterev on the left are evoked, abdominal reflexes are low, lower on the left. All types of sensitivity are reduced on the left half of the body. Coordination in the left limbs is impaired. In the fundus of the eye there are initial congestive optic discs. Based on the anamnesis and objective data, a diagnosis was made: a tumor of the right visual thalamus. The presence of dilation of the pupils after constriction with a direct reaction of the pupils to light gave reason to believe that the patient has a pathology in the midbrain. This is also indicated by the nystagmus of one right eye. Consequently, the tumor of the right thalamus affects the midbrain, and this, in turn, indicates the location of the tumor in the posterior parts of the thalamus, i.e., it is possible to clarify the topical diagnosis. During the operation it was determined that the tumor involved the posterolateral parts of the right visual thalamus. After the operation, a neurological examination of the patient showed that the dilation of the pupil disappeared after constriction when studying the direct reaction of the pupils to light, and the horizontal nystagmus of one right eye disappeared. This is due to the cessation of the impact of the thalamus tumor on the midbrain. Thus, the method we propose helps to identify midbrain pathology in children and increases the possibility of topical diagnosis. Example 2 Patient L, (ist. b. 913-97), 13 years old, entered the institute on 6/23-97 with complaints of a pressing headache of varying intensity, which occurs almost daily and lasts up to 6-7 hours, and for seizures that begin with a sensation of “coma” in the epigastric region. The “lump” rises up to the throat and falls, at which time the patient turns pale. Sometimes, after this, he loses consciousness and speaks without meaning, and pronounces the words correctly. He regains consciousness and feels a headache. Seizures last 2-3 minutes and are repeated daily. Speech deterioration is noted. At 5 months the mother noticed that the child began to smack for 2-5 seconds, after which he fell asleep. This was repeated once a week, once a day. By the age of one year the smacking had stopped. At the age of 2, he fell from a tree and was diagnosed with a concussion. After this, the seizures resumed, which already began with a feeling of “coma”. They were repeated once every 2-3 months. By the age of 5, seizures became more frequent to once a month. At the age of 7, they sometimes ended in loss of consciousness. At the age of 10, seizures became daily, and at the age of 13, her speech worsened. An objective study revealed elements of amnestic aphasia. The patient is left-handed. According to the claimed method, studies were carried out on the direct reaction of the pupils to light. It was found that after constriction, the pupils dilate. Movement in the limbs is full, strength in the arms and legs is 5 points, muscle tone is not changed. Deep reflexes on the hands are of medium alertness, uniform, knee reflexes are animated, uniform, Achilles are of average alertness, uniform, plantar reflexes are lively, uniform, abdominal reflexes are lively, uniform. During the finger-nose test - intention tremor on the left, poor standing on one leg, both on the left and on the right. The EEG reveals widespread changes in biopotentials with some predominance in the right hemisphere. Stem formations are involved in the process. The fundus and visual field are not changed, visual acuity is 1.0 in both eyes. A CT scan reveals a mass formation in the medial parts of the right temporal lobe. Based on the anamnesis, objective data and additional research methods, it was established that the patient has a tumor that is localized in the right temporal lobe, originates from the hippocampus and reaches the cortex. Dilation of the pupils after constriction, according to the claimed method, allowed us to talk about pathology in the midbrain, which is the result of the impact of the tumor on the midbrain. Consequently, it is located in the mid-posterior parts of the temporal lobe. On July 4, 1997, osteoplastic craniotomy was performed in the right fronto-parietal-temporal region. In the middle and posterior third of the temporal lobe, a volumetric formation was found, cystic-degenerated, gray-pink in color, emanating from the hippocampus and filling the entire cavity of the inferior horn. Histological examination showed pilocytic astrocytoma. Thus, our proposed method made it possible to detail topical diagnostics. It should be noted that there were no symptoms indicating pathology in the midbrain, except for dilation of the pupils after their constriction when studying the direct reaction of the pupils to light. Therefore, we can say that our proposed method for determining pathology in the midbrain in children is reliable.

Claim

A method for determining pathology in the midbrain in children, characterized in that the direct reaction of the pupil to light is examined and after constriction, if it gradually dilates, then the pathology in the midbrain is determined.

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The invention relates to medicine, more precisely, to ophthalmology and is intended for precise control of the quality of color vision among operators who use color analysis of various objects in their professional activities, as well as for studying the degradation of color vision in the process of professional work and/or life activity

The invention relates to medicine, more precisely to ophthalmology, and is intended for an accurate and objective assessment of the quality of color vision of subjects, which is necessary, for example: for professional selection and/or training of operators involved in visual observations of various color objects, as well as for studying degradation or change color vision in the process of professional work and/or life activity

What are malformations (anomalies) of brain development?

Brain malformations are congenital conditions that are caused by damage or abnormal development of the central nervous system. These anomalies are also called cephalic malformations of the nervous system. Such pathologies are congenital, which means that the disease is present, usually before birth. Although there are many congenital neurodevelopmental disorders, this informational resource will briefly cover conditions that are specific to the brain.

Brain defects are not necessarily caused by any one factor, but may be influenced by a number of hereditary or genetic conditions or environmental exposures during pregnancy, including factors such as medications taken by the mother, an infectious disease of the baby's mother, or radiation exposure. Some developmental abnormalities occur when the cranial sutures (fibrous joints that connect the bones of the skull) come together prematurely. Most head defects are caused by a disorder that occurs very early in the development of the fetal nervous system.

The human nervous system begins to develop from a small special plate of cells on the surface of the embryo. Early in development, this sheet of cells forms the neural tube, a narrow membrane that closes between the third and fourth weeks of pregnancy to form the brain and spinal cord of the embryo.

Four major processes are responsible for the development of the nervous system: cell proliferation, the process in which nerve cells divide into new generations of cells; cell migration, the process in which nerve cells move from their place of origin to the place where they will remain for life; cellular differentiation, the process by which cells acquire individual characteristics; and cell death, a natural process in which cells die. Understanding the normal, natural development of the human nervous system may allow better understanding of brain malformations and diseases.

Damage to the developing nervous system is a leading cause of chronic disorders associated with disability and sometimes death in infants, children and even adults. The extent to which damage to the developing nervous system harms the mind and body varies greatly. Most people with disabilities are ultimately unable to function independently in society. Some children and adults die, others remain completely disabled, and even more people with brain defects are partially functional, functioning significantly below normal performance throughout their lives.

Types of brain malformations

Anencephaly is a fetal malformation caused by a neural tube defect that occurs when the cephalic (head) end of the neural tube does not close. Develops inside the mother's womb, usually between days 23 and 26 of pregnancy, resulting in the absence of a significant portion of the brain, skull and scalp. Babies with this condition are born without the forebrain, the largest part of the brain, consisting mainly of the cerebrum, which is responsible for thinking and coordination. The remaining brain tissue is often left exposed—not covered by bone or skin.

Colpocephaly is a congenital defect in which there is an abnormal expansion of the occipital horns of the posterior or posterior portion of the lateral ventricles (cavities or lobes) of the brain. This enlargement occurs when there is insufficient development or absence of thickening of the white matter in the hindbrain. Colpocephaly is characterized by microcephaly (pathologically small head) and developmental delay. Other features may include motor abnormalities, muscle spasms, and convulsions.

Holoprosencephaly is a congenital pathology characterized by failure of the proencephalon (the forebrain of the embryo). During normal development, the forebrain is formed and the face begins to develop in the fifth and sixth weeks of pregnancy. Holoproencephaly is caused by the failure of the embryonic forebrain to divide to form the bilateral cerebral hemispheres (left and right halves of the brain), causing defects in facial development and in brain structure and function.

Hydranencephaly- a rare pathology in which the hemispheres of the brain are absent and are replaced by sacs filled with cerebrospinal fluid. Usually the cerebellum and medulla form normally. A baby with hydraencephaly may appear normal at birth. The baby's head size and spontaneous reflexes, such as sucking, swallowing, crying, and moving his arms and legs, may appear normal. However, after a few weeks, the child usually becomes irritable and has increased muscle tone (hypertension). After a few months of life, seizures and hydrocephalus may develop. Other symptoms may include blurred vision, lack of growth, deafness, blindness, spastic quadriparesis (paralysis) and intellectual deficit.

Iniencephaly- a rare neural tube defect that combines extreme retroflexion (reverse bending) of the head with severe spinal defects. An infected child tends to be short, with a disproportionately large head. The diagnosis can be made immediately after birth because the head is so retroflexed that the face faces upward. The skin of the face is directly connected to the skin of the chest, and the scalp is directly connected to the skin of the back. As a rule, there is no neck.

Lissencephaly, which literally means "smooth brain", is a rare brain abnormality characterized by microcephaly and the absence of normal convolutions in the brain. It is caused by defective neuronal migration, a process in which nerve cells move from their place of origin to their permanent location.

Megalencephaly, also called macrocephaly, is a disease that causes an abnormally large, heavy, and usually mentally underdeveloped brain. By definition, the brain weighs much more than average for the child's age and gender. Head enlargement may appear at birth or the head may become abnormally large in the first years of life.

Microcephaly is a neurological disorder in which the head circumference is less than the average for the age and gender of the child or child. Microcephaly can be congenital or develop in the first few years of life. The pathology can be associated with a wide range of conditions that cause abnormal brain growth, or from syndromes associated with chromosomal abnormalities.

Porencephaly- an extremely rare disease of the central nervous system resulting from a cyst or cavity in the cerebral hemisphere. Cysts or cavities are usually remnants of destructive lesions but are sometimes the result of abnormal development. Pathology can develop before or after birth.

Schizencephaly is a rare developmental disorder characterized by abnormal fissures or clefts in the cerebral hemispheres. Schizencephaly is a form of porencephaly. People who have clefts in both hemispheres or bilateral clefts often have developmental delays and poor speech and language skills and corticospanic dysfunction. People who have smaller unilateral clefts (clefts in one hemisphere) may have one side of the body that is underdeveloped and may have average or below-average intelligence. Patients with schizencephaly may also have varying degrees of microcephaly, developmental delay and cognitive impairment, hemiparesis (weakness or paralysis affecting one side of the body), or quadriparesis (weakness or paralysis affecting all four limbs), and may have decreased muscle tone ( hypotension). Most patients complain of seizures, and some may develop hydrocephalus.

Rare malformations (anomalies) of brain development

Exencephaly is a pathology in which the brain is located outside the skull. This condition usually occurs in embryos as an early stage of anencephaly. As an exencephalic pregnancy progresses, the neural tissue gradually degenerates. It is impossible to find an infant with this defect because the defect is incompatible with survival.

Macrocephaly is a pathology in which the head circumference is greater than the average for the age and gender of the child or child. It is a descriptive, not diagnostic, term and is common to a variety of disorders. Macrocephaly can also be inherited. Although one form of macrocephaly may be associated with developmental delays and cognitive impairment, mental development is normal in about half of cases. Macrocephaly can be caused by an enlarged brain or hydrocephalus. It may be associated with other disorders such as dwarfism, neurofibromatosis and tuberculous sclerosis.

Microencephaly is a brain malformation characterized by a small brain that may be caused by impaired proliferation of nerve cells. The pathology may also be associated with maternal problems such as alcoholism, diabetes or rubella (German measles). Genetics may play a role in some cases of microencephaly. Affected newborns usually have severe neurological defects and seizures. Severely impaired intellectual development is common, but motor impairment may appear longer in life.

Otocephaly is a fatal disease in which the main feature is agnathia - a developmental anomaly characterized by the complete or virtual absence of the lower jaw. The condition is considered fatal due to a poorly functioning pharyngeal arch. In otocephaly, agnathia may occur alone or together with holoproencephaly.

Craniostosis

Another group of less common headache disorders are craniostoses. Craniostones are cranial deformities caused by premature fusion or union of the cranial sutures. Cranial sutures are fibrous joints that connect the bones of the skull together. The nature of these deformations depends on which seams are affected.

Brachycephaly occurs when the coronal suture is delayed prematurely, causing the diameter of the skull to shorten back towards the back. The coronal suture is a fibrous joint that connects the frontal bone to the two parietal bones of the skull. The parietal bones form the top and sides of the skull.

Oxycephaly is a term sometimes used to describe the premature closure of a coronal suture plus any other suture, or it can be used to describe the premature fusion of all sutures. Oxycephaly is the most severe of the craniostoses.

Plagiocephaly is the result of premature unilateral fusion (joining one side) of the coronal or lambdoid sutures. The lambdoid suture connects the occipital bone with the parietal bones of the skull. Plagiocephaly is a condition characterized by asymmetrical distortion (flattening of one side) of the skull. It is common at birth and may be the result of a brain malformation, a restrictive intrauterine environment, or a tortoiseshell (spasm or tightening of the neck muscles).

Concept Scaphocephaly used for premature fusion of the sagittal suture. The sagittal suture connects the two parietal bones of the skull. Scaphocephaly is the most common of the craniostenoses and is characterized by a long, narrow head.

Trigonocephaly is a premature fusion of the metopic suture (the part of the frontal suture that connects the two halves of the frontal bone of the skull), in which a V-shaped abnormality occurs in the front of the skull. It is characterized by a triangular prominence of the forehead and closely set eyes.

Anomalies in brain development account for more than 30% of all congenital childhood pathologies. This is what, in most cases, is the cause of fetal death at the intrauterine stage. In the presence of this disease, only a quarter of children survive at birth, of which another 40% of babies die after birth. Often this park is not noticed during a medical examination in the maternity hospital, and its symptoms begin to appear a little later.

Brain malformations are abnormal formation of cerebral structural elements. They can lead to neurological signs. There are two types of such signs of brain development abnormalities:

• Mild;
• Heavy.

It is the latter that are the main reason why babies die in the womb. Cerebral changes in the brain lead to the child dying within the first two to three months.

It is important to know! Abnormalities or difficulties in brain development can be detected mainly after the first year of life. The formation of a child from the point of view of his brain continues until he is eight years old.

In the case of a developmental disorder, the nerves associated with the development of myotomes of the head do not work correctly, which causes disruptions in the entire human nervous system. In half of all cases, the malformation of the brain appears simultaneously with other pathologies, for example:

• Heart Park;
• Pathologies of the esophagus (for example, its atresia);
• Kidney fusion;
• Renal polycystic disease;
• Other.

Doctors usually try to detect such diseases in the early stages of pregnancy. This can usually be done using a test such as a fetal ultrasound or laboratory tests. The nervous system begins its development from the first week of pregnancy. By the 23rd day, the unborn child has already formed a neural tube.

It is important to know! If one of the ends of the neural tube is not completely fused, then this is the cause of disturbances in the development of the central nervous system.

On the 28th day, the fetus developed a brain vesicle, which will later be divided into two hemispheres of the brain. And only after this the convolutions, cortex and callosum will begin to appear.

On the basis of nerve cells, neurons will be formed, which will become the basis for the appearance of white and gray matter. The first organizes the channels through which the activity of the cerebral elements will pass. The second coordinates neural processes.

The most active development of the brain occurs in the period up to three months of the child. This developmental process continues until the child is eight years old.

Interesting fact! A newborn baby (when born at the normal due date) has the same number of neurons as an adult.

How to develop a child's brain correctly

Anomalies of brain development can occur at any stage:

1. The first six months have a direct impact on the number of neuron cells. If there are too few of them, then there will be an increase in cell separation and, as a consequence, hypoplasia of any of the parts of the brain.
2. After six months, there is a possibility of damage and death of the cerebral substance of the brain.

The causes of disorders can be completely different factors influencing the mother and the child. The development of pathology according to hereditary characteristics occurs only in 1 percent of all cases. Much more often the reasons are external factors, such as:

1. The influence of active chemicals. connections. Often the cause is poisoning with harmful substances, including medications and poor-quality food. This can also happen when inhaling exhaust gases, chemicals. Reagents and other dangerous gases.
2. Environmental contamination by radiation. The radiation background should not exceed the established normal limits. However, due to accidents, certain regions of the planet are not suitable for life, although people still live in them.
3. Air pollution with toxins. This usually happens in cities with millions of people or in industrial areas of cities (even small ones).
4. Unhealthy lifestyle of mother. In particular, this applies to the abuse of alcohol, nicotine cigarettes and drugs.
5. Problems with maternal health, in particular we are talking about pathologies of a dysmetabolic nature. For example, diabetes, hyperthyroidism and others. Especially if they are eliminated under the influence of drugs.
6. Use of medications with terrigenous properties. Usually this happens at an earlier stage while the woman does not yet know that she is pregnant. When there is a lack of control in sexual life, children are often the victims.
7. Infectious diseases regardless of the stage of pregnancy. Among the most dangerous are rubella, cytomegaly, listoriosis and toxoplasmosis.

All of these points are the reason that the brain in children does not develop as it should, which results in cerebral disorder of the nervous system.

Abnormalities in brain development

Basically, abnormalities of brain development belong to one of the following types:

• Anencephaly. With such a disease, the baby simply does not have a brain or skull bones. That is, with this pathology, life is impossible.
• Encephalocele. The cerebral membranes and tissues grow directly through the bone tissue. It is formed both centrally and asymmetrically. This disease is often confused with cephalohematoma. An accurate diagnosis can only be made using x-rays. In some cases, the pathology can be eliminated surgically.
• Microcephaly, which is a light and small brain, is a sign of underdevelopment. Occurs in one to five thousand children. The child's head becomes smaller, and there is a lack of normal proportion between the skull and face. 12% of children suffering from mental retardation suffer from this type.
• Macrocephaly, in which the baby's brain is too heavy and large. It is much less common than the previous option. Almost always, this pathology anomaly leads to the fact that a person cannot fully develop mentally. Asymmetry of the skull is possible due to the fact that one of the hemispheres is larger.
• Holoprosencephaly, in which the brain is not divided into separate hemispheres and is one complete sphere. This pathology leads to severe facial dysplasia. Children with this defect are born dead or die within the first 24 hours.
• Agyria, or as it is also called smooth brain. In this disease, the architecture of the brain is severely damaged. Babies experience motor and mental disorders and most often die during the first year of life.

These are just some of the defects in brain activity and brain development. To list all known diseases of this type, you will need a small reference book.

Video: Formation of a child’s brain

Brain abnormalities often form while a person is in the womb. In this case, the problem can affect both individual cerebral areas and the brain as a whole. Clinical symptoms are uncharacteristic. Most often, there is a delay in development, both psychological and mental, and an epileptic syndrome is formed. How severe the manifestations will be depends entirely on the severity of the lesion. Diagnosis is carried out using ultrasound before birth. Afterwards EEG, MRI of the brain and neurosonography are used. Treatment is symptomatic, since it is impossible to completely get rid of brain abnormalities.

Of all congenital diseases, problems with the brain occur in 1/3 of cases. Often this problem leads to the death of the fetus. Only a quarter of all children survive. Also, in newborns it is not always possible to detect an anomaly immediately after birth, so the complications are quite sad.

Description of the problem

What is it - a malformation of the brain in children? This is a disease in which the anatomical structure of cerebral structures is disrupted. How noticeable the symptoms will be depends in all cases on the degree of damage. In up to 75% of all cases, antenatal fetal death occurs. The timing of manifestation is always different. As a rule, symptoms of abnormalities appear in the first months after birth. But due to the fact that the brain is formed before the age of eight, most of the defects become active only after a year. There are often situations when anomalies occur with problems of other organs, for example, fusion of the kidneys, esophageal atresia, and so on. Today, medicine strives to diagnose the problem before the birth of the child in 100% of cases. This is done by gynecologists and obstetricians. Treatment usually involves pediatricians, neurologists, neurosurgeons and neonatologists.

Brain Formation

In order to have an idea of ​​what brain structures the defect affects in a newborn, you need to understand exactly how this human organ is formed.

The construction of the nervous system begins already in the first week of pregnancy. The neural tube is finally formed by the 23rd day of gestation. If its fusion does not occur completely, then cerebral anomalies occur. The anterior brain vesicle, divided into two lateral ones, forms the basis of the cerebral hemispheres. Formed by the 28th day of pregnancy. After this, the cortex, convolutions, basal structures of the brain, and so on are formed.

The division of nerve cells during the embryonic stage forms the gray matter, as well as glial cells, which make up the human brain. Gray matter is responsible for the functioning of the nervous system. Glial cells make up It is responsible for the connection of all cerebral structures. If a child is born at term, then by the time of birth he has the same number of neurons as an adult. Over the next three months, the brain develops intensively.

Causes of anomalies

The causes of brain developmental defects can be different. Failure can occur at any stage of organ formation. If it takes place in the first six months of pregnancy, then the child experiences hypoplasia of parts of the brain, and the number of neurons produced is reduced. Even if the cerebral substance is already fully formed, it can die due to a malfunction. Most often, the cause of this problem is considered to be the influence on the pregnant woman and, accordingly, the fetus of harmful substances that have a teratogenic effect. In other cases, fetal brain malformation occurs in 1% of cases.

Another influential reason is exogenous. Many chemical compounds have a teratogenic effect. It is caused by both radioactive contamination and some biological factors. Problematic ecology can have a detrimental effect, causing harmful substances to enter the body of a pregnant woman. Smoking, alcoholism and drug addiction can also lead to the formation of abnormalities. Diabetes mellitus and hyperthyroidism lead to the same effect. Some medications also have teratogenic effects. Doctors do not prescribe such drugs to pregnant women, but there are cases when at an early stage nothing is known about the existence of the fetus. Only one dose is enough for a defect to form. Infections suffered by a pregnant woman can lead to abnormalities. Rubella, cytomegaly and others are considered especially dangerous.

Types of anomalies

Unfortunately, congenital malformations of the brain have a large number of varieties. Let's look briefly at each of them:

• Anencephaly. Represents the absence of the brain and skull bones. Instead of an important organ, the child has many connective growths and cysts. There are times when the “brain” is exposed or covered with skin. This pathology is considered fatal in any case.
• Heterotopia. During neural migration, some neurons may be delayed and not reach the cortex. Such clusters can be single or multiple. The form can be tape or nodular. It differs from tuberous sclerosis in that the contrast does not accumulate. A similar malformation of the brain in children is manifested by oligophrenia. The severity of symptoms depends on the size and number of heterotopions. If the accumulation is single, then the first manifestations may appear after 10 years.
• Encephalocele. The pathology affects the bones of the skull; they do not connect in some places. In this case, deformation of cerebral tissues and membranes is observed. The disease develops along the midline. Some children have an asymmetrical problem. Sometimes the disease can mimic cephalohematoma. In such cases, x-rays are used to make an accurate diagnosis. The prognosis depends entirely on the size and contents of the encephalocele. If the protrusion is small and there is nervous tissue in the cavity, then surgery can be used.
• Focal cortical dysplasia, or FCD. This malformation of the brain is accompanied by the presence of huge neurons and abnormal astrocytes in the organ. As a rule, they are localized in the frontal and temporal parts of the skull. In the first time after the development of the disease, the child may experience demonstrative motor phenomena. They take the form of gestures. An example is marking time and so on.
• Microcephaly. The problem is characterized by a decrease in brain volume and mass. This happens due to the underdevelopment of the organ. Occurs once every 5 thousand newborns. In this case, the child’s head circumference is reduced, and the skull has disturbed proportions. Oligophrenia occurs in 11% of all patients with microcephaly. Sometimes idiocy develops. In addition, the child is lagging behind in physical development.
• Hypoplasia of the corpus callosum. Most often accompanied by the development of girls in the risk zone. Ophthalmic defects, dystrophic foci and other problems may occur. This malformation of the brain can be detected by ophthalmoscopy.
• Macrocephaly. Characterized by an increase in brain volume. Microcephaly is less common. Manifests: Some patients experience convulsive syndrome. There is partial macrocephaly, when the volume and weight of only one of the brain hemispheres is increased. The brain section of the skull is asymmetrical.
• Micropolygyria. There are a large number of small convolutions on the surface of the cortex. Normally there should be 6 layers of the cortex, in patients - no more than four. It can be local or diffuse. The latter is manifested by epilepsy, which develops after a year, mental retardation, problems with the pharyngeal and masticatory muscles.
• Cystic cerebral dysplasia. This malformation of the brain is accompanied by the formation of cystic cavities in the organ. They connect to the ventricular system. Cysts can be of completely different sizes. In some cases, they develop only on one hemisphere. The appearance of cysts can manifest as epilepsy, which is not treatable with anticonvulsant therapy. If the cysts are single, then over time they resolve.
• Pachygyria. The main convolutions are strengthened, but the tertiary and secondary ones are completely absent. The furrows shorten and begin to straighten.
• Holoprosencephaly. The hemispheres are not separated, being a single hemisphere. are also considered one. The shape of the skull is noticeably disturbed, and there may be somatic defects. As a rule, such children are either stillborn or die within the first 24 hours.
• Agiriya. Absence of convolutions or their underdevelopment. In addition, the architecture of the cortex is disrupted. The child has a disorder of mental and motor development, as well as seizures. As a rule, such children die in the first year of life.

Additional views

In addition, there are phylontogenetically determined malformations of the human brain. They are characterized by the absence of separation of the hemispheres. In some cases, the forebrain is not at all or partially divided into hemispheres. Another type of disease is the correct development of the skull, but the absence of the cerebral hemispheres.

There is such a thing as phylogenetically determined malformations of the human brain. In short, these are anomalies that no longer occur in modern conditions, but were inherent in our ancestors. There are three types of such defects. The first is associated with underdevelopment of organs. If we talk only about the brain, then this is the absence of convolutions, the cortex, and the non-separation of the hemispheres. Sometimes a small number of thickened convolutions are found. The second type is associated with the preservation of embryonic structures that were previously characteristic of ancestors. The third type is characterized by atavistic defects, due to which the organs are not in the place where they should be, but where they were previously located under normal conditions in their ancestors.

Diagnostic methods

If we are talking about severe malformations of the brain, then an external examination will be sufficient for diagnosis. In other cases, you need to pay attention to the condition of the child in the first year of life. Cramps and muscle hypotonia may occur. To exclude the hypoxic or traumatic nature of the lesion, it is necessary to consider the anamnesis. As a rule, if there was no asphyxia in the child at birth, fetal hypoxia or trauma during childbirth, then most likely the pathology is congenital. During pregnancy, diagnosis is carried out using ultrasound. Already in the first trimester, using this method it is possible to prevent the birth of a child who has a severe cerebral anomaly.

Additional diagnostic methods

Another type of diagnostics is neurosonography. It is carried out through the fontanel. After birth, an MRI of the brain can be done. It will allow you to study the problem 100%, understand what the nature of the disease is, where the anomaly is located, whether there are cysts, what size they are, and so on. If there is a convulsive syndrome, then the selection of therapy is carried out after an EEG. If we are talking about familial cases of cerebral anomalies, then before and during pregnancy you need to be observed by a geneticist. In this case, DNA analysis and genealogical examination are done. In order to identify problems with other organs, an ultrasound, x-ray, and so on are done.

Treatment

Therapy is mainly aimed at reducing symptoms. In case of congenital malformation of the brain (code Q04 is assigned according to ICD-10), the child should be observed by a pediatrician, neonatologist, neurologist and epileptologist. If there is a convulsive syndrome, then it is necessary to prescribe anticonvulsant therapy. Most brain abnormalities are accompanied by the development of epilepsy. It is not treatable with anticonvulsant monotherapy. Therefore, two drugs are used at once, for example, Levetiracetam and Lamotrigine. If hydrocephalus occurs, the doctor carries out dehydration therapy. If necessary, bypass surgery is performed. To improve the body’s metabolism, as well as return brain tissue to normal functionality, it is necessary to take B vitamins, glycine, and so on. Nootropic drugs are allowed only if there is no episyndrome.

Treatment of mild defects

If a child has a mild degree of brain malformation (according to ICD-10 code - Q04), then neuropsychological correction is carried out. Doctors recommend that the child work with a psychologist and attend art therapy. Children should be sent to specialized schools. If such methods of therapy are carried out, the child will be able to take care of himself. This will also reduce the level of mental retardation and help the child adapt to society.

Forecast

The prognosis is usually unfavorable, but also depends on the degree of the defect. If epilepsy develops at a young age, which does not respond to standard therapy, then doctors consider this symptom to be unfavorable. A brain defect together with somatic problems also does not provide a high chance of long-term survival. Therefore, it is important to understand even before the birth of a child that he has problems with brain development.

Results

As a conclusion, it must be emphasized that the described problem cannot be cured. Any therapy is aimed at relieving symptoms. Most sick children die within the first 3 years of life. Moreover, a small percentage of those affected survive until this period. Most often, children are either stillborn or die in the first day or first year.

Unfortunately, it is impossible to identify all the causes of malfunctions in the body that lead to brain defects. But it should be noted that a pregnant woman needs to monitor her health as carefully as possible and get rid of all bad habits. There is no guarantee that seemingly ordinary smoking will not cause a malfunction in the formation of the fetal brain.

Those children who are born and live to at least 10 years old take pills all their lives. It is difficult for them to walk, do some things on their own, and speak. Of course, it all depends on the degree of brain damage. There are those children who have a slight deviation. The important task of a parent is to spend all the time with the child and develop him. A small percentage of children are able to integrate well into society and exist quietly on their own. The chance is small, but it is there.