The hydrocephalus represents a pathological medical condition with increase of cerebrospinal fluid in an expanding ventricle system (brain cavities). This causes an increased pressure inside the skull, also known as increased intracranial pressure. This may develop slowly or quickly.

Infants present an abnormally enlarged head circumference (demonstrated on the head circumference evolution curve), a tense and bulged fontanelle, a conspicuous eye position (the so-called sundown phenomenon), as well as irritability and difficulties in drinking.

In older children, when the cranial sutures are closed, symptoms of increased intracranial pressure occur (headache, vomiting, impaired consciousness, impaired vision, epileptic seizures). Longer condition of increased pressure will damage the brain and optic nerves, finally leading to blindness or even death.

We distinguish two forms:

Obstructive hydrocephalus, where the cerebrospinal fluid cannot flow its normal path, due to some kind of blockade which can be a mass lesion such as a tumor, cyst, or malformation. A common cause however is stenosis of the aqueduct (the duct connecting the upper and lower brain cavities).

The treatment of the obstructive hydrocephalus aims, whenever possible, at removing the obstruction (remove tumor for example). An alternative treatment may be to create another pathway for the flow of cerebrospinal fluid by endoscopic ventriculostomy or shuntplacement.

Non-obstructive hydrocephalus (hydrocephalus malresorptivus)  is caused by impairment of the natural cerebrospinal fluid resorption areas, mostly caused by hemorrhage or infection. In particular, the still immature brain of premature infants is endangered by intracranial hemorrhages. Here treatment with a shunt is indicated. The shunt is a silicon catheter which drains the cerebrospinal fluid from the ventricles into the abdomen (peritoneal cavity) regulated by a valve.