Hydrocephalus

Hydrocephalus is a condition in which excess fluid builds up in your brain. The word "hydrocephalus" comes from the roots "hydro" meaning "water" and "cephalus" meaning "head." The fluid that accumulates is cerebrospinal fluid (CSF), a fluid that normally surrounds your brain and spinal cord.

It can also occur in adults as a result of injury or disease. In infants, hydrocephalus enlarges the head, and in both infants and adults, the resulting compression can damage brain tissue.

With early detection and surgical intervention, the prognosis improves but remains guarded. Even after surgery, such complications as developmental delay, impaired motor function, and vision loss can persist. Without surgery, the prognosis is poor: Mortality may result from increased intracranial pressure (ICP) in people of all ages; infants may also die prematurely of infection and malnutrition.

Causes

The causes of hydrocephalus are not all well understood. Hydrocephalus may result from genetic inheritance (aqueductal stenosis) or developmental disorders such as those associated with neural tube defects including spina bifida and encephalocele. Other possible causes include complications of premature birth such as intraventricular hemorrhage, diseases such as meningitis, tumors, traumatic head injury, or subarachnoid hemorrhage blocking the exit from the ventricles to the cisterns and eliminating the cisterns themselves.

Signs and symptoms

The symptoms of hydrocephalus vary according to the child's age and how far the disease has progressed. The increased pressure in the brain squeezes the soft tissues, causing damage and distorting them. At first, an infant might become increasingly irritable. Because a very young infant's skull bones have not yet fused together, the first visible sign might be a bulge in the area between the skull bones called the soft spot, or fontanel. The build up of fluid keeps the soft spot from fusing together, which results in a gradual increase in head size. Without treatment, the infant will become increasingly lethargic. In older children, symptoms might include headache; nausea and vomiting; lethargy and drowsiness; vision problems caused by swelling of the optic disk (papilledema); a downward deviation of the eyes (sunsetting); balance, coordination, and gait problems; urinary incontinence; developmental delays; changes in personality; learning difficulties; and memory loss. Hydrocephalus is a cause of mental retardation.

Diagnosis

In infants, abnormally large head size for the patient's age strongly suggests hydrocephalus. Skull X-rays show thinning of the skull with separation of sutures and widening of the fontanels.

Treatment

Surgical correction is the only treatment for hydrocephalus. Usually, such surgery consists of insertion of a ventriculoperitoneal shunt, which transports excess fluid from the lateral ventricle into the peritoneal cavity.

A less common procedure is insertion of a ventriculoatrial shunt, which drains fluid from the brain's lateral ventricle into the right atrium of the heart, where the fluid makes its way into the venous circulation.

Complications of surgery include shunt infection, septicemia (after ventriculoatrial shunt), adhesions and paralytic ileus, migration, peritonitis, and intestinal perforation (with peritoneal shunt).

Antibiotics are usually used aggressively with any sign of infection. Severe infections may require the shunt to be removed.

Follow-up examinations generally continue throughout the child's life to evaluate the child's developmental level and to treat any intellectual, neurologic, or physical problems.

Visiting nurses, social services, support groups, and local agencies can provide emotional support and assist with the care of the child with hydrocephalus who has significant brain damage.

Prevention

Protecting the head of your infant or child from injury by handling your child carefully may help prevent the development of hydrocephalus. Prompt treatment of infections such as meningitis and other disorders associated with hydrocephalus may reduce the risk of developing the disease. If you're pregnant, you may reduce the risk of hydrocephalus in your unborn baby by taking precautions to reduce the likeliness of premature birth.