HYDROCEPHALUS IN CHILDREN
Hydrocephalus is excessive accumulation of cerebrospinal fluid (CSF) within brain cavities (Ventricles).
CSF is produced in the ventricles and circulates through the brain and spinal cord before it is reabsorbed from the surface of the brain into the blood stream. When this pathway is blocked due to any reason, backpressure develops in the ventricles and results in hydrocephalus. CSF has many important functions viz. Nourishment, cushion like protection of the nervous tissue and to carry waste products away.
Congenital (present at birth)
Hydrocephalus is caused by a complex interaction of genetic and environment factors. Aqueductal stenosis (narrowing) is the most frequent cause. Blockage of fourth ventricle outlet (Dandy Walker Syndrome) or Chiari malformations (in association with Spina Bifida) are other common causes.
Acquired (development later in life)
Hydrocephalus can result from infection, bleeding (hemorrhage) head trauma, tumors and cysts. The most common cause in our country is meningitis (infection).
Hydrocephalus can be detected by observing the childs behavior and a few physical signs, and it can be confirmed with simple tests.
In a small baby
Poor feeding, high pitch cry, excessive sleepiness, enlarging head with soft areas on the top (fontanelles), inability to move eyes upwards and vomiting will prompt the diagnosis.
In an older child
Lethargy, irritability and a drop in the school performance are observed.
Ultrasonography (USG), computerized Tomography (CT scan) or magnetic resonance Imaging (MRI) will confirm the diagnosis, show the degree of ventricular enlargement, the site of the blockage and offending cause(s) and a few physical signs, and it can be confirmed.
There is no known way to prevent or cure hydrocephalus. If obstruction is found on CT scan due to a tumor or cyst, it can be excised by a neurosurgeon to re-establish the CSF pathway. In other situations the most effective treatment is insertion of a shunt (at a known pressure gradient). The shunt is a hollow silicone tube, placed into the ventricular system, diverting the CSF flow to the peritoneal cavity of the abdomen (VP shunt). If abdominal cavity is unable to absorb the fluid due to some disease viz. TB or cyst, the shunt can be placed via the jugular vein to reach the right atrium of heart (VA shunt). Shunts can also be placed in the pleural (chest) cavity.
In communicating hydrocephalus (malabsorption of CSF but no blockage) a Lumboperitoneal (LP) shunt can also be performed on order children where the tube goes from the spinal cavity to abdomen.
The operation to insert a shunt is performed with extremely strict sterile precautions by either a pediatric surgeon or neurosurgeon. This procedure takes about 1-2 hours.
The child will be observed for a short time, in the recovery area and then transferred to the bed. He/she will be allowed fluids after 12 hours and normal food after 24 hours.
Usually after 5-7 days the child can go home. Sometimes, a CT scan may be repeated to confirm the success of the treatment.
In selected cases as judged by the neurosurgeon, endoscopic procedures may be used to create alternative CSF pathways(s) within the brain (e.g. third ventriculostomy, aqueductal stenting) and shunt may not be necessary.
These techniques are developing and may find wider applications in the future.
Blockage of the shunt may occur occasionally due to twisting or break at the connections. These need immediate rectification by a small surgery.
Blockage can occur even later with waste products especially in case of hemorrhage or meningitis. Sometimes in a growing child the tube may slide out of the peritoneal cavity, due to an increase in the childs height. All these can be surgically corrected. Infection of the shunt can occur, as with any implant in the body and should be watched for by observing fever, redness or swelling over the shunt tube or a wound discharge. An infected shunt needs to be removed.
Symptoms of blocked shunt
The symptoms of shunt blockage are related to raised pressure in the brain. The child who was all right may start vomiting and appear drowsy (sleepy). These symptoms may be accompanied by fever. Whenever a blocked shunt is suspected, you must seek urgent medical help.
Effects of hydrocephalus
In most cases the shunting procedure successfully controls hydrocephalus. Many children will have normal intelligence and development. They may be slow in learning or acquiring coordination.
Blockages, infection and developmental delays require that the family be aware of these problems and actively participate in observation and care of the child.
How long is the shunt tube kept?
The shunt tube, unless blocked or infected by itself causes no problem and can be kept in place for years. Only if the surgeon is convinced that it is safe to remove the shunt, it may be removed. In many cases the tube is kept for a lifetime without causing any problems.
Last created on 09-10-2001
Last updated on 18-11-2006