Causes of cerebral palsy

Causes of cerebral palsy.


Cerebral palsy develops as a result of damage or underdevelopment of different brain or spinal cord parts and always begins in childhood. As for adults, especially the elderly, brain damages such as apoplectic attack or cerebral hemorrhage may also cause movement disorders, which will not be very different from what we have seen in cases of child cerebral palsy. However there is one fundamental difference between the brain of adult and child: adult’s brain is already formed and no longer grows, and the child’s brain grows and develops, it does not work to the full yet. Therefore the recovery chances are higher, although there are some difficulties. Practically any child’s impaired function can be trained to a certain degree.


In cases of cerebral palsy the affected area in the brain does not expand and the damage does not worsen, while in cases of some other diseases superficially resembling cerebral palsy, such as muscular dystrophy, destructive changes appear in the brain or spinal cord system and unfortunately these changes are slowly grow. So sometimes it is necessary to consult with geneticist before the diagnosis will be proved. In other words the brain of a child with cerebral palsy has «preserved» damage that does not change by itself. As a child is often born with the damage, so over time in the process of his growth and development the signs of brain damage change. Thus cerebral palsy is not progressive, but modificatory movement and posture control disorder that appears in early childhood. Cerebral palsy of a baby or a child a little older may develop after a car accident and traumatic brain injury. If a child is injured in later life, most likely the diagnosis of cerebral palsy won’t be set though the signs will be formally similar.


Evolution of views on the causes of cerebral palsy


There were two basic theories of cerebral palsy origin before now. One of them was proposed by psychoanalyst Sigmund Freud. He believed that brain damage originates before a child’s birth during antenatal period. Another orthopedic surgeon William Little suggested that the brain is damaged in childbirth. According to Little’s theory the main cause of cerebral palsy is the lack of oxygen to baby’s brain during the childbirth. Now it is known that newborn babies are much easier suffer the lack of oxygen than it was imagined earlier and passage through the birth canal which is, surely, difficult and traumatic for a child, leads to brain damage not so often. Also there is an opinion that body’s immune system is involved in cerebral palsy origin; mother’s body begins to reject the fetus damaging it by its defense cells.


About 40-50% of children with cerebral palsy were born premature and were very small. The risk of brain damage during the childbirth of an immature child is very high because brain vessels are still very fragile and can poorly sustain natural labor activity. Blood vessels around the ventricles, small cavities in the brain, of premature babies are so fragile that their damage is often the cause of bleeding – intraventricular hemorrhage. Small uncomprehensive hemorrhage in the brain ventricle is not dangerous, but if it is extremely intense, constricts the ventricle wall or damages the brain tissue, it can lead to serious abnormalities. It is important that precisely those brain regions, which are known to be responsible for motor control, suffer. In cases of severe intraventricular hemorrhages cerebral palsy develops for more than 90% of such babies. Most hemorrhages are seen on ultrasound investigation of the brain (neurosonography). Therefore it is really important to keep watch over a newborn baby, who was born premature, all the time and certainly ultrasound investigation of the brain should be used while watching. In the process of such examination you can see everything that happens in the ventricles and brain tissue and diagnose both slight harmless injuries and more severe ones. Providing early treatment it is often possible to avoid the formation of cerebral palsy. But do not panic if the first ultrasound investigation reveals abnormalities, usually the first ultrasound investigation always reveals some changes. Several ultrasound investigations carried out up to one year of age always reveal how changes occur in the baby brain during the treatment. That’s why it’s not completely fair to talk about the diagnosis of cerebral palsy just immediately after birth, but after a year when treatment has not brought expected results.


Although intraventricular hemorrhages are, undoubtedly, the important cause of cerebral palsy, but there are other factors that can affect baby’s brain during the fetal life. One of the most important events in the embryonal stage of fetus life is that the brain develops very quickly: by the 12th-13th week of pregnancy the fetus, though it is still tiny, looks like a real man. Legs, hands, heart and everything else are already there, but the brain is still like a small ball; its rapid development starts in the second and third trimesters of pregnancy and continues after birth. There is not only intensive process of brain cells fission, but they also move within the brain, so nerve tracts are formed. It is no wonder that such major changes in such a small organ are easy to be prevented. We know about some factors that have a negative impact on the fetus brain development. For example, these are alcohol and nicotine, some infections, such as rubella. Undoubtedly, many factors contributing to fetus brain damage have not been studied yet.


Sometimes such damage may occur after a birth of a baby. In cases of hemiplegic form of cerebral palsy it is known if not the reason, but the mechanism of brain damage, because it is similar to characteristics of apoplectic attack in adults. Certain artery supplies certain brain region. Bleeding, that occurs in case of rupture of an artery (arteriorrhexis), or thrombosis, that occurs in case of arterial occlusion, lead to damage of certain brain region. Some cases of hemiplegic form of cerebral palsy are associated with postpartum brain damage, which probably happens due to the vessels fragility of a newborn; for some reason these vessels have no time to become sufficiently strong during the fetal life.


Today with the help of modern research methods (see below) we can examine damaged brain regions. Sometimes it helps to understand when they have appeared, though not always it helps to find out the causes of damage. Sometimes we can only say: “This brain region is damaged, but we do not know the reason.”


Diagnosis and diagnostics of cerebral palsy.


Grounds for concern can arise early. Attending doctor can warn about possible problems in child’s development, but it does not mean that we have a case of cerebral palsy; we are talking about possible problems. Sometimes it’s meningitis or convulsions, sometimes it may be seen that a child is retarded in motor development, etc.


So it comes a moment when a doctor must decide if cerebral palsy has formed or not. To a certain degree cerebral palsy diagnostics is to exclude other causes that can lead to similar abnormalities. Often there are more threatening diseases such as neoformations or degenerative diseases. Blood tests are done, blood composition is analyzed, and chromosomes which carry genetical information are examined. By the way cerebral palsy is rarely inherited. There is only one form of spastic diplegia of hereditary nature, but it occurs in one out of twenty cases of cerebral palsy.


Also researches to see the brain structure are conducted. Computed tomography or magnetic resonance imaging allows to see where the damaged region is located, but special thing about this research is that babies should be under general anesthesia as it is necessary to lie still for about 30 minutes.


General anesthesia is not always indicated for treatment, it is not always good, so caution and reasonableness are necessary. Ultrasound investigation of the brain (or neurosonography) can be used for newborn children, but only until the fontanelle is not fully closed, i. e. until the skull bones are not completely knitted; this method has specific value because you cannot see the entire brain and the diagnosis of cerebral palsy is usually set after one year old age, when fontanelle is almost closed.


There are also more sophisticated research methods such as positron-emission tomography, which allows to explore certain metabolic activity in the brain. Undoubtedly, there will be new and more accurate methods of brain research.


An important research is electroencephalography, it is especially recommended at suspicion on convulsions. However in cases of cerebral palsy a curve of electroencephalography can often be of imperfect nature and in this situation it is difficult to determine whether the child has epilepsy, whether he has got convulsions or not.


Very often child’s family feels that doctors tell them about child’s condition unclearly and incomprehensibly. That’s as may be, but parents’ shock from the news that their son or daughter has serious abnormalities often prevents them from perceiving the information, and they are able to get used to the disaster only after some time. In such situation it’s better for parents to be prepared in writing form for conversation with doctor. There is one important moment that must be understood from the very beginning: it’s impossible to eliminate brain damage, today there are no ways to move the damaged region away from the brain and replace it with healthy nerve cells. But child’s brain is flexible and some damaged centers may be compensated by others to a certain degree. Stem cell therapy gives some hope for this, but we have little information about it yet and this therapy is very expensive. However there are many other ways to help a child with cerebral palsy.

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