Hydrocephalus (water on the brain) is a pathological enlargement of the spaces in the brain that are filled with cerebrospinal fluid.
CSF (also called cerebrospinal fluid or neural fluid) is a clear, colorless fluid with few cells that surrounds the brain and spinal cord. Its main function is to absorb shocks and other mechanical forces and is essential in supplying nutrients and cells. CSF is continuously produced by ultrafiltration of the blood in a special plexus of veins in the brain and brain surfaces. It must also be continuously reabsorbed, i.e. drained into the venous or lymphatic system, in order to avoid an increase in pressure in the fluid spaces. A pathological excess accumulation of CSF in the fluid spaces of the brain, the so-called ventricles, is called hydrocephalus (water head).
Since cerebrospinal fluid is continuously produced, it must always be reabsorbed. After cerebral haemorrhages or in the case of brain tumours, however, there can be a disturbed absorption (reabsorption) into the venous and lymphatic system. The resulting increase in intracranial pressure usually leads to a change in consciousness, which can sometimes increase very quickly.
The aim of the therapy is to relieve pressure quickly by draining the cerebrospinal fluid. Various therapy options are available for this. On the one hand, an attempt can be made to drain the cerebrospinal fluid via a lumbar puncture (i.e. the insertion of a hollow needle into the spinal canal in the area of the lumbar spine). Drainage can also be done directly from the cavity system of the brain using external ventricular drainage (EVD). Both options provide short-term relief. Alternatively, an endoscopic ventriculocysternostomy (EVT) is an option for CSF circulation disorders. As a permanent solution, a thin tube is implanted for permanent cerebrospinal fluid drainage, which directs the cerebrospinal fluid from the cavities of the brain into the abdominal cavity, where the fluid is then reabsorbed. This system is called a ventriculo-peritoneal shunt.
Normal pressure hydrocephalus is also called senile hydrocephalus. This is a chronic expansion of the fluid spaces of the brain. As a rule, there is only a brief increase in intracranial pressure, usually at night. Because of the slow development of this clinical picture, in contrast to acute hydrocephalus, the symptoms usually occur gradually. A combination of gait disorders, impaired mental abilities (neurocognitive deficits) and incontinence is typical. However, especially in the initial phase, these symptoms can also be only mildly pronounced.
