The brain is located in a liquid called cerebrospinal fluid. The fluid is excreted into the ventricles within the brain and passes into the area around the brain, where it is absorbed by membrane that surrounds that area. If a disturbance occurs during the development of the fetus, or if the flow of the cerebrospinal fluid is blocked, the liquid accumulates in the brain chambers.
This causes the increased pressure, and the brain is swollen. This is a condition called hydrocephalus (”water on the brain”). To adapt to this swelling, the skeletal bone of the skull expands and breaks, and the head is larger than normal. In severe cases, permanent brain damage may occur.
Hydrocephalus can also occur in older infants as a result of brain damage due to infection or tumor.
Initial stages of this disorder may be seen at birth if the extent of the newborn’s head is significantly higher than the average (350 mm). If so, the head is often measured during the first few weeks. If the head grows too fast tests, including X-rays, are made.
Approximately one out of 10,000 children is born with hydrocephalus. The disorder occurs more frequently in conjunction with spina bifida.
If hydrocephalus is quite advanced at birth, inevitable brain damage and developmental backwardness are unavoidable, and premature infant death is likely due to infection.
The disorder can be detected in the uterus by X-ray and ultrasound. If the disorder is quite advanced in pregnancy, it will be necessary, for the mother’s own safety, to perform the caesarean section.
If hydrocephalus is not too advanced, it can be alleviated by operation after birth. A newborn is given general anesthesia, and a small opening is drilled in the skull. A thin tube with a one-way valve is inserted into the opening; one end of the tube is inserted into the brain and the other in the main blood vessel leading to the heart. This way, the fluid is being drained from the brain into the bloodstream.
After this operation the size of the newborn’s head gradually decreases to normal. During the first year of life, a child should be routinely monitored, approximately once a month. As the child grows the tube can be clogged, so the child can become irritable and start vomiting. If this happens, contact your doctor immediately. If the tube is clogged, the child will be taken into hospital where the tube will be replaced with a new one.