Alternative names
Water on the brain
Definition
Hydrocephalus is an accumulation of cerebrospinal fluid in the ventricles of the brain, leading to their enlargement and swelling.
The term hydrocephalus is derived from two words (hydro = water, cephalus = head). Hydrocephalus is a condition in which too much cerebrospinal fluid (water-like fluid produced in the brain that circulates around and protects the brain and spinal cord) accumulates within the ventricles (the cavities or chambers within the brain which contain the cerebrospinal fluid. There are two lateral ventricles and midline third and fourth ventricles) of the brain and may increase pressure within the cranium (the part of the skull that holds the brain). The condition may occur at any age.
Today hydrocephalus is treated by a surgical procedure, performed by a neurosurgeon, in which a tube called a shunt is placed in to the child’s body. The shunt channels the flow of fluid away from the brain or spinal cord into another part of the body, where the fluid can be carried away in the bloodstream. This is a relatively common operation. In most cases, the procedure successfully controls hydrocephalus, but, unlike many surgical procedures that can cure a disease, the placement of a shunt does not cure hydrocephalus. Except in rare cases, hydrocephalus is a lifelong illness. And as with any long-term illness, complications can occur to which parents must be alert. The changes that signal a possible complication require your understanding, because a complication left undiagnosed and untreated could cause severe brain damage, or threaten the life of your child.
Complications
Problems with the shunt, such as kinking, blockage, or tube separation
Infection
Meningitis
Encephalitis
Infection of the area to which CSF is shunted
Intellectual impairment
Neurologic damage (decrease in movement, sensation, function)
Physical disabilities
Complications of surgery
Although hydrocephalus is almost always treated successfully with the surgical procedure of a shunt. Shunt malfunction occurs in about 2 – 4% of cases. Shunt malfunction simply means that the shunt is not able to divert enough fluid away from the ventricles in the brain. Its two most common cases are obstruction of the shunt and infection. These are serious problems and must be treated appropriately. Most complications that require revision of the shunt occur within 6 months to 1 year after surgical placement of the shunt.
Obstruction – When shunt malfunction occurs, it is usually a problem with a partial or complete blockage of the shunt. The fluid backs up from the site of the obstruction and, if the blockage is not corrected, almost always results in a recurrent symptoms of hydrocephalus. Shunt obstruction can occur in any of the components of the shunt. Most commonly, the ventricular catheter becomes obstructed by tissue from the choroid plexus or ventricles. The catheters or the value may become blocked with blood cells or bacteria. Also, the tip of the peritoneal catheter may become obstructed by loops of the bowel or by fat tissue in the abdominal cavity.
Infections – Shunt infection usually is caused by a child’s own bacterial organisms, and is not acquired from exposure to other children or adults who are ill. The most common organism to produce infection is called Staphylococcus epidermiditis, this is normally found on the surface of the child’s skin and in the sweat glands and hair follicles deep within the skin. Infections of this type are most likely to occur 1 month after surgery, but may occur up to 6 months after the placement of a shunt.
Children with VP shunts are most prone to abdominal infection, whereas children with VA shunts may develop generalised infection which can quickly become serious. In either case, the shunt infection must be treated immediately to avoid life threatening illness or possible brain damage.
Other Complications – In rare cases, other complications may develop with patients who receive shunts. Although they are unlikely to occur, described briefly for your information.
Shunts are very durable, but there have been instances in which the components of the shunt have become disengaged as a result of the child’s growth and have moved within the body cavities where they originally were placed. Very rarely, a valve will fail because of mechanical malfunction. However, it is possible that the valve pressure for a child’s shunt system can drain fluid too rapidly or too slowly. To restore a balanced flow of fluid it may be necessary to replace the shunt with a new shunt containing a more appropriate pressure vale. Over-drainage of the ventricle could cause the ventricle to decrease in size to the point where the brain and its meminges pull away from the skull. If blood from broken vessels in the meninges becomes trapped between the brain and skull, resulting in a subdural haematoma, further surgery is required.
Symptoms of a blocked shunt
Headache
Vomiting
Vision changes
Crossed eyes
Uncontrolled eye movements
Loss of co-ordination
Poor gait (walking pattern)
Mental aberrations (such as confusion or psychosis)
Changes in facial and brow contours, eye spacing, or protrusion