Hydrocephalus occurs in infants and adults. It is usually congenital, but can also develop in the course of life due to certain circumstances (e.g. infections, brain tumors).
Hydrocephalus is caused by a disturbed fluid balance in the head: the cavities in the brain (ventricles) fill with an excessive amount of cerebrospinal fluid, enlarge and thus displace the solid brain substance. This leads to a sharp increase in pressure in the brain.
Infants react differently to the increase in pressure than adults, as their skulls are not yet fully formed. Their skull bones have not yet grown together. Due to the increased pressure in the brain, their skull can enlarge and thus partially compensate for the pressure.

In hydrocephalus, impaired cerebrospinal fluid circulation increases brain pressure © pikovit | AdobeStock
Hydrocephalus can already be detected during prenatal (prenatal) diagnostics: The enlarged ventricles can be clearly seen on the images of the unborn child.
Hydrocephalus occurs in various forms - depending on how it developed in the patient.
Hereditary causes of hydrocephalus are, for example
- a malformation of the brain,
- skull bone malformations and
- impaired brain development.
Acquired forms of hydrocephalus are usually caused by
Hydrocephalus occlusus is the most common form of hydrocephalus, accounting for around 60 percent of cases. It is caused by
- Brain tumors,
- brain malformations,
- inflammation of the brain and
- blood clots.
The cerebrospinal fluid builds up at a constriction in the brain and cannot drain away, causing the intracranial pressure to rise. A typical constriction is the aqueduct. It connects the third and fourth ventricles and is sometimes narrowed or even completely closed from birth.
Hydrocephalus nonresorptivus is less common(30 percent). In this case, there is reduced resorption, usually as a result of meningitis. This means that too little cerebrospinal fluid flows out.
Hydrocephalus hypersecretorius (frequency: approx. 10 percent) can be the result of carbon monoxide or mercury poisoning. Brain inflammation is also considered to be the cause of this form of hydrocephalus.
A congenital severe brain malformation (too little brain mass) leads to hydrocephalus e vacuo. Both the outer and inner cerebrospinal fluid spaces are enlarged from birth. Accordingly, they also fill up with more cerebrospinal fluid.
The symptoms of hydrocephalus are differentiated between infants or children and adults.
Hydrocephalus symptoms in infants and young children
- Increased head growth (percentile cutting)
- Abnormally large head (macrocephalus)
- bulging fontanel (space between the skull bones that is not yet closed)
- prominent (congested) cranial veins
- an altered eyeball position in which a white stripe of the sclera is visible above the cornea (sunset sign)
- fasting vomiting
- Balcony forehead (large head with prominent forehead)
Symptoms of hydrocephalus in children/adolescents and adults
- Severe headaches
- fasting vomiting
- Visual disturbances (double vision)
- Clouding of consciousness up to coma
- gait disturbances
- impaired memory function
- Reduced ability to concentrate
Additional hydrocephalus symptoms in older adults
Hydrocephalus is diagnosed using imaging techniques such as
Which procedure is most suitable depends on the age of the patient and the circumstances of the examination.
In infants, the ultrasound procedure is usually used initially. The bones of the skull are not yet firmly fused together. This enables a satisfactory image quality of the ultrasound.
In individual cases, the intracranial pressure is also measured in the clinic's neurosurgery, neurology or neuropaediatrics department.
Hydrocephalus is treated surgically in the neurosurgery department of a clinic.
One proven method is to create a shunt. A tiny hole is drilled in the patient's skull and a very thin catheter with a silicone tube is inserted. From there, it runs under the patient's skin and directs the excess cerebrospinal fluid into the abdominal cavity, for example. There the body breaks it down (ventriculo-peritoneal shunt/VP shunt). A valve located behind the ear adapts to the respective pressure level in the ventricle. This reduces the high intracranial pressure.

Using a VP shunt, excess cerebrospinal fluid can be drained into the abdominal cavity via a catheter © rumruay | AdobeStock
The shunt is barely visible from the outside and is also used in infants. Infants and children who have a shunt inserted at an early stage can develop normally in the subsequent period, depending on the underlying disease. However, they have an even better prognosis if the doctor is able to eliminate the cause of their hydrocephalus.
If the third ventricle of the brain is affected (e.g. aqueductal stenosis), an endoscopic ventriculostomy (ETV) can be used. This involves drilling a tiny hole in the wall of the ventricle.
Drug (symptomatic) treatment is only used for hydrocephalus for a short time at most.
Regular check-ups are important for all patients with hydrocephalus. This enables doctors to detect and treat new constrictions or a dysfunction of the shunt system at an early stage.