As part of every wellness visit during infancy, the pediatrician takes a few moments to measure your baby's head. Such measurements are needed to check for normal development of the brain and skull. A rapid increase in the size of a baby's skull over the first few weeks or months of life may indicate the presence of hydrocephalus, a potentially dangerous condition in which excess fluid accumulates in the area surrounding the brain and in the ventricles within the brain. Fortunately, hydrocephalus can be treated surgically. If the treatment is delayed, however, permanent neurological damage may result.
WHAT CAUSES HYDROCEPHALUS?
Hydrocephalus develops as a result of any disease or malformation affecting the flow of cerebrospinal fluid, which is produced in the ventricles and absorbed from the spaces surrounding the brain and spinal cord. When an illness or anatomical abnormality blocks the flow of cerebrospinal fluid or interferes with its absorption, the fluid builds up, creating pressure within the brain. In infants whose fontanels (soft spots between skull bones) are still open, the head may become enlarged. After the skull bones have fused, the excess fluid cannot expand them. Instead, pressure builds up within the skull, compressing the brain.
In many cases, hydrocephalus is present at birth, which suggests that a malformation within the brain or spinal column is the cause. Hydrocephalus is a common complication of a condition called spina bifida, in which part of the spinal cord protrudes through the backbone. In some cases, meningitis—an infection of the membranes surrounding the brain and spinal cord—causes hydrocephalus. Infections in the mother also can lead to hydrocephalus in the fetus. In older babies and children, head injuries sometimes cause hydrocephalus, particularly if there is bleeding within the skull. Growths within the skull sometimes produce hydrocephalus as well.
WHEN SHOULD I SUSPECT THAT MY INFANT HAS HYDROCEPHALUS?
Look for a swelling in the fontanel on the top-center part of the head. Also check for unevenness in the shape of the head, particularly enlargement in the forehead and temples. An older child who develops hydrocephalus may initially suffer from nausea, vomiting and severe headache, particularly on awakening. Pressure within the skull also can lead to listlessness and impaired speech and coordination.
DOES HYDROCEPHALUS REQUIRE MEDICAL ATTENTION?
Yes. Increased pressure within the skull is a medical emergency.
HOW CAN THE PEDIATRICIAN TELL IF MY CHILD HAS HYDROCEPHALUS?
If a newborn is at risk of hydrocephalus because of premature birth or some other condition, the pediatrician may take frequent measurements of the head to detect an abnormal growth rate. To determine the cause of hydrocephalus in an infant or confirm the presence of hydrocephalus in an older child, computed tomography (CT) or magnetic resonance imaging (MRI) studies of the brain are needed.
WHAT TREATMENTS ARE AVAILABLE?
The standard treatment is the insertion of a narrow tube (a shunt) in one of the ventricles of the brain and diverting excess fluid to another body cavity, most often the abdomen. The tube is placed in the ventricle at the side of the head and tunneled under the skin along the side of the neck and chest to the upper abdomen. Often the shunt must stay in place indefinitely, being adjusted periodically to prevent blockage or accomodate growth.
If an anatomical problem underlies the hydrocephalus, it may be amenable to surgery.
COPING WITH HYDROCEPHALUS
• Even if the cause is never discovered, most children who receive prompt, appropriate care can develop normally—with mental capacity completely intact—and lead healthy lives.
• Relax the reins. Most children with shunts can participate with their peers in all activities except for contact sports.
• Seek support. Ask your pediatrician or hospital social worker to put you in touch with other parents whose children have similar problems. In many communities, support groups for parents with chronically ill children already exist.
GETTING HELP
Call your pediatrician if the soft spots on your infant's head seem to be bulging out or if your child has the following combination of symptoms:
