Hypoxic-ischemic CNS Damage In Newborns - Symptoms And Treatment

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Hypoxic-ischemic CNS damage in newborns

Hypoxia in newborns can lead to serious disturbances in the brain. This problem is quite acute, since almost every 10 babies suffer from hypoxia to one degree or another. Hypoxic-ischemic damage to the central nervous system is the most common complication that develops against the background of oxygen starvation of the newborn. It is often diagnosed in children who were born prematurely.

Effective methods of dealing with hypoxia in newborns are still simply absent, although scientists do not stop working in this direction. Moreover, science is completely powerless against the complications caused by hypoxia. No drug is able to restore dead brain cells. Although, according to the assurances of scientists, such funds have already appeared and are at the stage of clinical trials.

The central nervous system reacts painfully to a lack of oxygen. When it comes to a newborn baby and a baby in the womb, the issue of oxygen starvation becomes even more acute. The baby's brain is at a developmental stage, so he needs constant and uninterrupted nutrition. Any pathogenic influences experienced by a pregnant woman or received during childbirth can adversely affect the state of the child's central nervous system. The nerve tissue will be damaged, which in the future will manifest as neurological disorders.

The degree of hypoxia varies. It can be mild and severe, it can last for several minutes, or it can last for days or even months. However, hypoxia will necessarily provoke disturbances in the work of the brain.

If, with a mild course of hypoxia, these disorders do not have pronounced symptoms and can independently pass after a certain period of time, then with deep hypoxia the changes will be irreversible. In this case, the brain undergoes organic damage, which can make the child disabled.

Hypoxia can develop both during the intrauterine life of the fetus and during childbirth, provided that they have a pathological course. In addition, hypoxic-ischemic disorders are observed in children who suffer from pathology of the respiratory system, with problems associated with blood clotting, with a sharp decrease in blood pressure, and more.

There are two concepts used in medical terminology. Hypoxic-ischemic damage to the central nervous system is spoken of in the case when the complications of hypoxia are severe. Also in this context, the term hypoxic-ischemic encephalopathy can be used. It is most commonly used when the brain is mildly affected.

Although there is still debate about whether the brain can recover from hypoxia, most doctors are convinced that this is possible. The nervous system of children is armed with certain mechanisms that are aimed at protecting themselves on their own. Moreover, some scientists insist that a child's brain can even regenerate. After all, not every newborn who has undergone deep oxygen starvation becomes disabled. Moreover, not all of them develop any neurological disorders in the future.

If hypoxia is severe, then the most immature areas of the brain located in its stem part, as well as subcortical nodes, will be damaged first. Dangerous not only acute, but also prolonged hypoxia, which may not be accompanied by severe symptoms. Such oxygen starvation provokes diffuse damage to the cortical structures of the brain. During hypoxia, the child's body triggers a certain mechanism that redistributes blood flow in such a way that most of it will be directed specifically to the brain stem. Therefore, with prolonged oxygen starvation, its gray matter will suffer mainly.

Due to the fact that complications of hypoxia can be fatal, neurologists should pay close attention to examining infants. This is especially true for those children who have suffered hypoxia during childbirth, regardless of its severity. It is necessary to exclude all adaptive manifestations of the body (for example, tremor), to establish the neurological status of the child, to detect possible disturbances in the functioning of the nervous system. When detecting hypoxic lesions abroad, they rely on the principle of staging pathology. In Russia, a systematic approach is used, focusing on syndromes that may indicate the development of complications.

Content:

• Why do CNS lesions occur, stages of their development
• Symptoms of hypoxic-ischemic damage to the central nervous system
• Treatment
• Forecast

Why do CNS lesions occur, stages of their development

Perinatal damage to the central nervous system is said to be when a child has been exposed to negative factors during the neonatal period, during childbirth or while in the womb.

The reasons that can provoke disturbances in the functioning of the child's nervous system:

• Violation of blood flow in the uterus and placenta. Placental thrombosis, fetal growth retardation, bleeding in a pregnant woman.
• Drinking alcohol during pregnancy, smoking and being treated with certain drugs.
• Severe blood loss during labor, entanglement of the umbilical cord around the baby's neck. Hypotension or bradycardia in a child, birth trauma.
• Heart defects, disseminated intravascular coagulation syndrome, pathologies of the respiratory system, episodes of respiratory arrest in an infant who was born.

The lack of oxygen in arterial blood is a factor that triggers metabolic disorders in the nervous tissue. At the same time, individual neurons or their entire groups begin to die. Under such conditions, the brain tissue becomes maximally susceptible to any fluctuations in blood pressure. If at this time the child develops hypotension, then the pathological process is further aggravated.

Disorders of metabolic processes in the brain provoke acidosis of its tissues, which entails cerebral edema with an increase in intracranial pressure. This causes massive death of brain cells.

Deep asphyxia affects the functioning of all organs of the child. Kidneys, intestines, liver suffer. Hypoxia causes tissue death of these organs.

There are differences in the course of complications caused by oxygen starvation in full-term and premature infants. So, if a child, born on time, underwent hypoxia, the cerebral cortex, its subcortical structures and the brain stem will be affected to a greater extent. If the baby is premature, then he will most likely develop periventricular leukomalacia, that is, areas of necrosis will be concentrated in the area of the lateral ventricles of the brain.

The severity of hypoxic encephalopathy has a direct relationship with the depth of ischemic brain damage.

In this regard, there are:

• Mild or 1 severity. Neurological disorders are transient, after 7 days they will be completely stopped.
• Moderate or 2 severity. Hypoxic-ischemic disturbances persist for more than one week. At the same time, the child's nervous system is either depressed or hyperexcitable, convulsions are observed, intracranial pressure is increased, but the increase is not stable. Disorders from the autonomic nervous system also appear.
• Severe form of impairment or grade 3. In this case, the child will be either in a coma or in a stupor. He has convulsions, there is swelling of the brain, the work of internal organs is impaired.

Symptoms of hypoxic-ischemic damage to the central nervous system

If the child's central nervous system is affected, then doctors will establish this fact from the first minutes of his life. Symptoms directly depend on the severity of the baby's condition.

1st degree

If hypoxic-ischemic encephalopathy has a mild course, then the child's condition will be stable. On the Apgar scale, the baby gets 6-7 points. He will have cyanotic staining of the skin, muscle tone is somewhat reduced.

From the side of the nervous system, the following symptoms are observed:

• The nervous reflex excitability is increased.
• Sleep is disturbed, the child is anxious.
• The chin and limbs tremble slightly.
• The child often spits up.
• An increase or, on the contrary, a decrease in reflexes is possible.

As a rule, over the next 7 days after the baby is born, all these pathological symptoms will be stopped. The kid becomes calmer, begins to gain weight. There are no pronounced disorders of the nervous system.

2nd degree

With the second degree of hypoxic brain damage, the symptoms will be more intense. Most often, infants with moderate severity of hypoxic-ischemic encephalopathy suffered from oxygen starvation while still in the womb, and were also exposed to adverse factors during labor. On the Apgar scale, such a child is given a mark of 5 points, he has arrhythmias, deaf heart sounds are heard.

Nervous system disorders are as follows:

• Reflexes are depressed, this is true, including with respect to the sucking reflex.
• Muscle tone is reduced, voluntary movements are minimal or absent altogether.
• Intracranial pressure rises.
• The skin is bluish in color.
• Autonomic disturbances are observed: there are periodic stops in breathing, the pulse can accelerate, bradycardia is often diagnosed. The intestines contract weakly, thermoregulation is impaired.
• The child often spits up, may suffer from constipation or diarrhea, and gains weight slowly.

The higher the intracranial pressure of the child, the more anxiety he will show. The skin is sensitive, restless sleep. The child's chin and hands tremble, fontanelles bulge. The baby has oculomotor disorders, nystagmus. Seizures can also indicate increased intracranial pressure.

By the 7th day after the birth of the child, his condition stabilizes. However, he must receive intensive care. By this time, neurological symptoms do not completely disappear. If the pathology progresses, then the inhibition of brain activity increases, and muscle tone decreases. The child may fall into a coma.

Grade 3

If a child is diagnosed with grade 3 hypoxic-ischemic lesions, then a woman always has severe preeclampsia in the second half of pregnancy. She suffers from high blood pressure, she has impaired renal function, severe edema.

The baby is born with the symptoms of oxygen deprivation, the delay in development is clearly traced. If the childbirth proceeded with complications, then the existing violations will only worsen.

The child suffers from severe circulatory disorders, may not breathe, muscle tone and reflex activity are often absent. If resuscitation measures are not carried out urgently, then the child dies.

In the first hours after his birth, there is a depression of the brain, a coma develops. Reflexes and physical activity in the baby are absent, the pupils are dilated, the reaction to light is zero.

Edema of the brain is manifested by convulsions, respiratory arrest and cardiac arrest are possible. The pressure in the pulmonary artery rises, urine filtration worsens, blood pressure drops, intestinal tissue begins to die, the liver stops functioning, and DIC develops.

Post-asphyxia is a consequence of severe neonatal hypoxia. The child is practically immobilized, does not cry, does not react to painful stimuli, to touch, the skin is pale, the body temperature is lowered. The baby has difficulty swallowing and sucking movements, so the woman cannot feed him on her own. Without intensive care, the child will die. The prognosis is unfavorable; a conclusion cannot be made about the stability of the state earlier than 10 days from the moment of his birth.

The subsequent increase in neurological deficit characterizes all forms of hypoxic-ischemic disorders. The fact is that neurons that were damaged as a result of hypoxia continue to die.

Possible options for the course of pathology:

• The child's condition is improving rapidly. The forecast is favorable.
• Neurological disorders disappear by the time the baby is discharged from the maternity hospital. The forecast is favorable.
• Neurological disorders continue to progress. The prognosis is poor.
• During the first month of life, the child becomes disabled.
• An unfavorable course with a hidden increase in neurological disorders that develop during the first six months of a child's life.

Encephalopathy of the newborn is divided into 3 periods:

• An acute period that lasts for the first month. At this time, the maximum disturbances of nervous activity are observed. They can be mild, or come to a coma.
• A recovery period that can last throughout the year. At this time, the child may develop a convulsive syndrome, hydrocephalus, increased neuro-reflex excitability, and a lag in physical and mental development.
• A distant period when the consequences of the transferred hypoxia manifest themselves. Some symptoms may disappear while others appear, for example, a child may have a speech delay.

Treatment

To diagnose hypoxic-ischemic encephalopathy, it is required to identify the characteristic symptoms in the infant, to study the history of the management of the pregnant woman. Also in the diagnosis of a pathological condition, instrumental examination techniques are assisted, including:

• Neurosonography.
• Echocardiography.
• Computed tomography and magnetic resonance imaging of the brain.
• Coagulogram of blood.
• Doppler study of cerebral vessels.

The difficulty in the treatment of hypoxic-ischemic complications lies in the fact that not a single drug can help restore the damaged nerve tissues. However, it is still possible to normalize the work of the brain to one degree or another.

Depending on the prevalence of specific symptoms and on the severity of hypoxia, the therapeutic scheme will differ.

If hypoxia is of moderate or mild severity, then the child is shown taking diuretics, nootropic drugs, medicines to eliminate seizures. Provided that hypoxia has a severe course, the patient is urgently treated with intensive therapy.

When a child has symptoms of mild hypoxic-ischemic encephalopathy, but there are no convulsions, the doctor can limit himself only to monitoring the patient. Sometimes, with such a clinical picture, Diazepam may be indicated, but for a short period of time. This drug can inhibit the development of a child, so it is prescribed only for strict indications.

Pantogam and Phenibut have a complex nootropic and inhibitory effect on the child's nervous system. Nitrazepam is prescribed to normalize the child's sleep. Also for this purpose, Valerian extract, lemon balm, motherwort, mint can be used. Massage and hydrotherapy have a sedative effect.

If hypoxia is severe, then the child is prescribed anticonvulsants, diuretics (Furosemide, Mannitol, Diacarb) and Magnesium sulfate.

The child is urgently resuscitated if he has a delay in breathing or cardiac arrest. Shows the connection of the patient to the ventilator, the introduction of cardiotonic drugs, the conduct of infusion therapy.

Diuretics are prescribed as the main drug for hypertensive-hydrocephalic syndrome. Preference is given to a drug called Diacarb. It can be used to treat children of any age. Surgery is used when conservative therapy does not bring the desired effect. For this purpose, bypass surgery is performed with the withdrawal of cerebrospinal fluid into the peritoneal cavity or into the pericardial cavity.

To relieve seizures and reduce the excitability of the nervous system, drugs such as Diazepam, Phenobarbital, Clonazepam, Phenytoin are prescribed. If the child is a newborn, then preference should be given to barbiturates, namely Phenobarbital. If the child is breastfeeding, then he is prescribed Carbamazepine.

To relieve increased muscle tone, use Baclofen or Midocalm. If muscle tone, on the contrary, is lowered, then the child is prescribed Dibazol and Galantamine. Physical therapy is helpful in treating complications caused by hypoxia. For this, the child is sent for a course massage, with him they are engaged in therapeutic gymnastics. Reflexology and water procedures have a good effect.

If the child has difficulties in speech development, which becomes obvious by the end of the first year of life, then he is shown taking Nootropil and Encephabol, vitamins of group B. The baby must necessarily interact closely with the speech therapist and the defectologist.

Prescribing a large number of drugs is not always the correct tactic for treating children who have undergone hypoxia with subsequent encephalopathy. Often, unnecessarily, the child is prescribed Diacarb, nootropic drugs, vitamins, Actovegin. However, if the encephalopathy is mild, these drugs will not be helpful as the body will be able to recover on its own. Moreover, they have age-related contraindications, so their unjustified use may even be harmful.

Forecast

The child's recovery is possible, while a full recovery occurs. However, it cannot be ruled out that the baby will remain disabled if hypoxia was severe. It is also possible to develop minor cerebral dysfunction with a low-symptom course of the pathology.

The consequences of hypoxic-ischemic encephalopathy are epilepsy, cerebral palsy, hydrocephalus, and oligophrenia. The last violation is persistent in time, it is impossible to cure oligophrenia.

If a child lags slightly behind in development during the first year of life, but at the same time receives adequate treatment, most likely, he will catch up with his peers in the near future, and will be no different from healthy children.

Author of the article: Alekseeva Maria Yurievna | Therapist

Education: From 2010 to 2016 Practitioner of the therapeutic hospital of the central medical-sanitary unit No. 21, city of elektrostal. Since 2016 she has been working in the diagnostic center No. 3.