Hydrocephalus

What Is Hydrocephalus?

In medicine, hydrocephalus refers to various diseases with dilation of the internal cerebral ventricles. Cerebrospinal fluid, or CSF, is produced in the brain and flows from the cerebral ventricles down along the spinal cord and around the nerve roots. The adult human has about 150ml of CSF and exchanges it three times a day, producing about 450ml of CSF per day. Most of these diseases affect infancy. About 1 in 2,000 fetuses are affected. In addition, a unique role in idiopathic normal pressure hydrocephalus (age-related brain pressure) affects adults.

What Are the Causes of Hydrocephalus?

In principle, the balance between production, passage, and reabsorption of cerebrospinal fluid into the bloodstream is disturbed in hydrocephalus. This can be caused by the following:

• Meningitis
• Cerebral hemorrhages
• Tumors and cysts in the area of the head or spine
• Surgical interventions on the central nervous system

Hydrocephalus in Children

The special feature of infantile hydrocephalus is that the head enlarges due to the increased pressure because the bone scales of the skull are not yet firmly fused. Therefore, hydrocephalus in infancy is easily visible. Often the head enlarges even before the child shows other symptoms such as developmental delay, nausea, or vomiting.

Hydrocephalus in Adults

There is no more margin in adults, as the bones of the skull are firmly fused and no longer cave in. Therefore, CSF congestion in adults leads to increased pressure in the cerebral ventricles, which triggers symptoms early.

Hydrocephalus Symptoms

Typical symptoms are:

• Headache
• Nausea
• Vomiting
• Blurred vision
• Gait disturbances
• Cognitive impairment
• Urinary incontinence
• Disturbances of consciousness

There are usually no symptoms in normal pressure hydrocephalus caused by increased intracranial pressure. Instead, three specific symptoms appear here: gait disturbance, cognitive impairment, and urinary incontinence.

Depending on how quickly the hydrocephalus develops, the symptoms can occur slowly or quite suddenly and even become life-threatening.

How Is Hydrocephalus Diagnosed?

The examination of choice for imaging the ventricular system is primarily a form of cross-sectional imaging. Here, computed tomography (CT) is preferred. For specific imaging of soft tissues in the head, such as malformations, cysts, or tumors, magnetic resonance imaging (MRI) is carried out. A lumbar puncture of the lower spine can measure the pressure in the CSF system. In addition, a CSF sampling can be tested simultaneously to reduce pressure and consequently relieve symptoms. In occlusive hydrocephalus, however, lumbar puncture is contraindicated.

Hydrocephalus Therapy

Hydrocephalus treatment aims to restore a balance between CSF production and CSF outflow. This can be achieved by restoring CSF outflow or creating a new outflow pathway.

Acute onset hydrocephalus with increased intracranial pressure can be quickly relieved by placing external ventricular drainage. This involves drilling a hole in the skull and advancing a catheter through it into the ventricular system. The cerebrospinal fluid can drain through this catheter, while at the same time, the pressure in the skull is continuously measured and monitored. In the case of occlusive hydrocephalus, the aim is to surgically remove the outflow obstruction caused by a hemorrhage, cyst, or tumor and revoke it. If this is not possible, there is the option of surgically creating a new outflow pathway.

Prognosis and Life Expectancy

As with most brain malformations, the prognosis of hydrocephalus is considered unfavorable. It is less favorable if other brain malformations are present or brain tissue is destroyed. Generalized infection of the brain also worsens the prognosis. In most cases of hydrocephalus occurring without accompanying malformations, mental and neurological developmental disorders are to be expected. However, with timely treatment and the establishment of regulated pressure conditions, development can also be almost normal.

Which Doctors and Clinics Are Specialized in Hydrocephalus?

Neurologists and neurosurgeons are specialists in hydrocephalus. After surgery, inpatient hospitalization is usually required.

Sources:

• Mumenthaler, Mattle: Neurologie. 12. Auflage. Thieme 2008, ISBN 978-3-133-80012-9.
• Masuhr, Neumann: Duale Reihe Neurologie. 6. Auflage. Thieme 2007, ISBN 978-3-131-35946-9.
• Berlit: Klinische Neurologie. 3. Auflage. Springer 2011, ISBN 978-3-642-16920-5.