Hydrocephalus is a condition involving the abnormal accumulation of cerebrospinal fluid in and around the brain.
The brain and spinal cord are collectively known as the central nervous system (CNS). A fluid called cerebrospinal fluid (CSF) surrounds the CNS. The CSF protects and nourishes the brain. The ventricles are a series of chambers inside the brain that contain and help circulate CSF. Normally, the CSF flows through the ventricles in the brain and is then reabsorbed into the bloodstream through the membranes that line the skull and spinal canal.
Hydrocephalus may be classified as obstructive or nonobstructive. Obstructive hydrocephalus occurs when the circulation of CSF in the brain is blocked. Nonobstructive hydrocephalus occurs when something interferes with the reabsorption of CSF into the bloodstream. As the CSF accumulates, the ventricles enlarge. They press on the soft tissue of the brain and cause the symptoms of hydrocephalus.
Symptoms of hydrocephalus vary, depending on the age of the child and the rate of fluid accumulation. Hydrocephalus in an unborn child can increase a baby's head size to the point where a C-section is necessary.
If hydrocephalus occurs in the first 1 or 2 years of life, the infant's head will enlarge more rapidly than normal. The fontanels (the soft spots on top of the head) will bulge and feel tense. Scalp veins will be dilated. The eyes may look downward. The infant may have stiffness in the arms and legs due to muscle spasms.
In the older child, the symptoms of hydrocephalus may not be as obvious. Because the bones of the skull have fused together, the head does not enlarge. The child may be have the following symptoms: drowsinessfatigueheadacheirritabilityloss of appetiteproblems with balance, coordination, and walkingurinary incontinencevomiting
A slowly worsening form of hydrocephalus may cause the following symptoms in a child: changes in personality and thinking abilitiesa gradual decline in school performancememory lossslow development
Obstructive hydrocephalus can be caused by: bleeding inside the braincysts, which are fluid-filled massesan inherited abnormality of the brain present at birthmeningitis, an infection of the membranes surrounding the brainmeningomyelocele, a severe form of spina bifida in which the spinal cord protrudes outside the bodytumors that block the flow of CSF within the brainviral infections in the brain of a fetus, which may be caused by a TORCH infection in the mother
Nonobstructive hydrocephalus can be caused by: bleeding over the surface of the brain, which can clog the membranes that reabsorb CSFleukemia, a type of blood cancermeningitis
Premature infants are at increased risk for developing this condition. This is because premature babies are more likely to develop bleeding inside or around the brain. The blood can block the membranes that reabsorb CSF, causing hydrocephalus. This risk increases with the degree of prematurity.
Intensive care of premature infants may help prevent some cases due to bleeding in the brain. Women who are or are planning to become pregnant are advised to take folic acid supplements to reduce the child's risk of developing spina bifida. Women who may become pregnant are also advised to make sure their routine vaccinations are up to date. This can help prevent certain TORCH infections of the unborn child during pregnancy.
Diagnosis of hydrocephalus begins with a medical history and physical exam. The healthcare professional may order tests, including: cranial CT scancranial MRImeasurement of intracranial pressure (the pressure inside the head)pregnancy ultrasound
Children with hydrocephalus may have permanent brain damage. IQ is generally lower than average. Behavior, memory, and learning problems may occur. Vision problems such as crossed eyes and poor eyesight are common.
Hydrocephalus is not contagious and poses no risk to others. If it is caused by an infection, such as meningitis, the infection may be contagious.
If a tumor or cyst is causing the obstruction, surgery to remove it may cure this condition. A ventriculoperitoneal shunt can be inserted to go around a blockage. This allows CSF to flow freely, relieving the pressure inside the brain. Shunts are usually made of special plastic materials.
One end of the shunt is inserted into one of the ventricles in the brain through a hole drilled into the skull. The other end of the shunt is tunneled under the skin. It is usually threaded down into the heart or abdomen. The shunts have a one-way valve that only allows fluid to flow away from the brain. Some shunts have a chamber placed under the scalp that allows the shunt to be pumped. Occasionally, shunt tubing needs to be replaced with longer tubing as the child grows.
Any surgery can be complicated by bleeding or reactions to anesthesia. The major complication of shunts, however, is infection. Over time, shunts can become blocked and may need to be replaced.
Management of hydrocephalus is a complicated process, requiring the input of a number of specialists. The child may have behavioral or learning problems that require special education and treatment.
Children with hydrocephalus need ongoing, long-term monitoring. The child's physical and mental development, learning ability, vision, and behavior will be closely watched. Any new or worsening symptoms should be reported to the healthcare professional.