Cerebral Palsy: Causes and Forms
Children's cerebral palsy ( cerebral palsy) is a severe disease of the nervous system associated with abnormalities or brain damage and accompanied by persistent but not progressive motor, coordination and in some clinical cases, intellectual disorders.The severity of the pathological manifestations of cerebral palsy in different patients differs: some babies become completely immobile and helpless, others may well learn how to move, self-service, learn and even work.Table of contents:
Causes of cerebral palsy
Causes of cerebral palsy, depending on the time of exposure to the baby, are divided into three groups :
- Intrauterine factors.
- Intranatal factors( various problems in childbirth).
- Postnatal factors( pathological conditions occurring during the newborn period - in the first weeks of life).
In most cases, when examining an anamnesis of a small patient, doctors discover not one but several reasons that could cause cerebral palsy.But there are also situations where it is not possible to find out exactly which factors triggered cerebral palsy.Therefore, the researchers suggest that a certain role in the development of the disease under consideration is played by the
Features of pregnancy and cerebral palsy
The fetal brain is the most vulnerable organ in the entire small body.Especially dangerous for nerve cells is oxygen starvation( hypoxia), infections, toxic substances, radioactive irradiation.
Fetal hypoxia may occur in the following situations:
- In case of a risk of abortion, when the placenta exfoliates and bleeding occurs.
- With severe toxicosis and gestosis.These complications of pregnancy appear, because the mother's body can not get used to the new condition, and various pathological changes take place there, including negative effects on blood circulation between the uterus and the placenta.
- With placental insufficiency - dysfunction, which leads to disruption of gas exchange between the blood of the mother and fetus.
- For maternal diseases, accompanied by narrowing of blood vessels and a low concentration of oxygen in the blood of a woman.Such ailments include diabetes, arterial hypertension, systemic autoimmune pathologies, anemia, heart defects, chronic lung diseases.
Serious brain damage and abnormalities may occur due to exposure to the fetus of infectious agents.The greatest danger in this regard is:
- Herpesviruses( including cytomegalovirus).
- Rubella virus.
All these infections can harm the fetus if the woman's organism meets them for the first time during pregnancy, that is, it must be a primary infection or a serious exacerbation( for example, genital herpes, cytomegalovirus infection).If a woman has been sick for a long time, and she has antibodies to these pathogens, the risk of CNS defects in the fetus is minimal.
The cause of development of cerebral palsy, as mentioned above, can also become effect on the fetus of toxic substances .These include drugs that have a teratogenic effect( the ability to cause malformations in the child), drugs, alcohol.
Intranatal causes of cerebral palsy
In childbirth, a child may develop acute hypoxia that damages the brain.It leads to this:
- Premature detachment of the placenta.The placenta loses its connection with the uterine blood circulation, so the blood flowing to the baby ceases to be saturated with oxygen.
- Heavy prolonged labor.
- A tight cord with the umbilical cord or an umbilical cord loop, in which blood circulation between the fetus and the placenta is impaired.
- Pelvic presentation of the fetus.When the head emerges from the birth canal, it compresses the umbilical cord, so if the doctors hesitate and do not help the baby to be born as quickly as possible, severe hypoxia may develop.
In addition to oxygen starvation, causes brain injuries caused by birth in cerebral palsy.Injury of the child's head can occur if the woman has a narrow pelvis, if the child is large or is incorrectly placed in the uterus, if the childbirth is swift or caused by medication.
The risk factor for the development of cerebral palsy is also the obstetrical forceps ( due to the possibility of brain damage this method of delivery is almost not used now), and squeezing the fetus from the mother's abdomen.
Premature birth and cerebral palsy
Preterm births, , are considered to be the most dangerous for the child in terms of development of cerebral palsy because premature babies are most susceptible to brain lesions such as hemorrhages and periventricular leukomalacia.And the smaller the baby, the risk of developing postpartum complications( in particular, cerebral palsy) is greater.For this reason, in many developed countries where children have learned to successfully care for children with a critically low body weight, the frequency of cerebral palsy in newborns is at a high level.
What can cause cerebral palsy after childbirth?
In the newborn period, the baby's brain remains very vulnerable. The following causes can cause irreversible changes in the CNS:
- Severe hemolytic disease, in which a large amount of toxic bilirubin is formed in the body of a newborn, damaging the structures of the central nervous system.
- Infectious diseases complicated by meningitis or encephalitis.
- Head injuries.
Important: does not include vaccinations in this group of reasons, because there is no confirmed data on the relationship between vaccination and the development of cerebral palsy.
Mechanisms of development of cerebral palsy
The main difference between cerebral palsy and other paralysis is the time of onset - this is the perinatal period ( from 22 weeks gestation to the seventh day of the child's life).The pathological influence on the brain that occurred in this period of time leads to a violation of the extinction of the pozotonic reflexes characteristic of newborns - changes in the muscle tone and posture when the body position is changed.
From the point of view of physiology, the interaction of the central nervous system and muscles is as follows: in response to any stimulation and change in the position of the body, the brain potentiates and directs signals along the nerve fibers to the muscles that cause contraction or relaxation of the muscle fibers.In this case, everything goes smoothly - one group of muscles is contracted, and the other( antagonists) relaxes or vice versa.Only thanks to such a clear interaction man normally moves. In cerebral palsy, the communication between the central nervous system and muscles is broken, so patients can not fully control their body .
In addition to locomotor activity and coordination, the child suffers from cerebral palsy.If the nuclei of the cranial nerves are affected, patients have problems with swallowing, sight, facial expressions.In the most severe cases, brain damage that causes the development of cerebral palsy becomes also the cause of the intellect disorders .
Forms of cerebral palsyRecommended to read:
There are five forms of infantile cerebral palsy:
- Little's disease ( spastic tetraplegia).This is the most common form of the disease, especially among premature babies.With her, the lower extremities of the child become immobile, but their hands are rarely affected.Violation of movements in the legs is caused by spastic( persistent muscle contraction), because of which the limbs do not bend and do not unbend at all.With the growth of the child, there are deformations of the joints and spine, but this does not mean that the pathology is progressing.
- The hemiplegic form. It is characterized by the immobility of one half of the body and spasticity, as in the first form of cerebral palsy.
- Atactic form. Its development is associated with the defeat of the frontal lobes of the brain and the cerebellum.In such patients discoordination of movements of different muscle groups, coordination disorder, tremor, speech and intellect disorders are noted.
- The diskinetic form of the .Most often occurs due to severe hemolytic disease of the newborn.The main signs are involuntary movements, a sharp change in the tone of the muscles and the position of the body, a violation of mimicry.Intellect in these patients, as a rule, does not suffer.
- Spasmodic tetraplegia is the most severe form of the disease, in which almost complete paralysis of the limbs is accompanied by constant convulsive attacks, a violation of intelligence and speech.Some patients are diagnosed with microcephaly.
Separately, is isolated as a mixed form of cerebral palsy, in which patients show signs of several forms of the disease.The task of doctors in such cases is to identify the leading syndrome and direct all efforts to correct it.
Zubkova Olga Sergeevna, medical reviewer, epidemiologist-doctor