CAUSES AND PATHOGENESIS OF PERINATAL BRAIN LESIONS

Аннотация

Fetal hypoxia is a non–specific manifestation of various complications of pregnancy and childbirth, primarily toxicosis of pregnant women. The degree and severity of toxicosis, its connection with the extragenital pathology of a woman (especially with diseases of the cardiovascular system) determine the duration and severity of fetal hypoxia, whose central nervous system is most sensitive to oxygen deficiency. Key words: perinatal lesion, central nervous system The aim of the study was to identify the clinical features of the course of perinatal CNS lesions and criteria for predicting the results of treatment of these disorders. Introduction. Among the causes of perinatal brain lesions, intrauterine and intranatal fetal hypoxia occupies a leading place, the second most important place belongs to the factor of mechanical traumatization of the child during childbirth – as a rule, in combination with one or another severity preceding intrauterine hypoxia. Also, the structure of etiopathogenetic factors of perinatal pathology includes infectious (including viral) and toxic-metabolic variants of damage to the nervous system. Thus, among the factors contributing to perinatal CNS damage, the following are distinguished: 1. Fetal intrauterine hypoxia. 2. Intranatal fetal hypoxia. 3. Mechanical injury during childbirth. 4. Infectious (viral) factors. 5. Toxic factors. 6. Hereditary factors. 7. A combination of these factors. Antenatal hypoxia leads to a slowdown in the growth of brain capillaries, increases their permeability. The permeability of cell membranes and metabolic acidosis increase, and cerebral ischemia with intracellular acidosis develops. Antenatal hypoxia is often combined with intranatal asphyxia. The frequency of primary asphyxia is 5%. Hypoxia and asphyxia are accompanied by a complex of compensatory and adaptive reactions, the most important of which is an increase in anaerobic glycolysis. The effect of hypoxia leads to a complex of 17 CURRENT APPROACHES AND NEW RESEARCH IN MODERN SCIENCES International scientific-online conference microcirculatory and metabolic disorders, which at the tissue level cause two main damages: hemorrhagic infarction and the development of ischemia followed by leukomalacia of the brain substance. Hemorrhagic (especially) and ischemic damage to the brain substance is facilitated by some manipulations in the first 48-72 hours of a child's life: the introduction of hyperosmolar solutions, artificial lung ventilation (ventilator) and associated hypoperfusion of the brain against the background of a drop in carbon dioxide voltage, insufficient correction of circulating blood volume, etc. Hemorrhagic infarction and ischemia most often develop in fetuses and newborns in the area of the periventricular plexuses – subependimally in combination with damage to the brain substance. Hemorrhage can also occur in the lateral ventricles of the brain and in the subarachnoid space. In addition to the described changes, the morphological substrate of hypoxia, as a rule, is the fullness of the brain, its general or local edema. In the pathogenesis of hypoxic-traumatic and hypoxic-ischemic encephalopathies, causes and effects change places, intertwine in complex "vicious circles". Violation of hemodynamics (macro- and microcirculation) leads to multivariate metabolic shifts (violation of the acid-base state and electrolyte balance, destabilization of cell membranes, hypoxemia and tissue hypoxia), and these shifts, in turn, exacerbate microcirculation disorders[9]. In premature infants, the damaging effect of intrauterine hypoxia is potentiated by immaturity, maladaptation in the intranatal period. The immaturity factor predisposes to mechanical traumatization of the child, especially with abnormal exposures, pelvic presentations, and some obstetric aids. Traumatization of the cervical and thoracic spinal cord is possible when protecting the perineum and even during cesarean section with a so-called cosmetic incision (insufficient for gentle removal of the baby's head). Chronic intrauterine intoxication can have both a non-specific damaging effect (hypoxia) and cause clearly defined metabolic disorders and, accordingly, specific clinical syndromes – fetal alcohol syndrome, nicotine syndrome, narcotic withdrawal syndrome. In recent years, the subtle mechanisms of the pathogenesis of hypoxic-ischemic brain lesions have been deciphered. The importance of intrauterine infections in the formation of pediatric cerebral pathology was first pointed out by 3. Freud (Freud S., 1897). Сonclusions:Currently, the leading role of intrauterine infections in the development of 1111HC and cerebral palsy has been convincingly proven. Particular importance is attached to intrauterine viral lesions: congenital rubella, herpetic infection, inclusive cytomegaly and toxoplasmosis, as well as 18 CURRENT APPROACHES AND NEW RESEARCH IN MODERN SCIENCES International scientific-online conference diseases caused by vari