Neurosurgical Conditions - Hydrocephalus

This term, which comes from the Greek and means water-brain, is not a specific disease, but encompasses a whole variety of conditions which, broadly speaking, cause an accumulation of fluid within the brain, and a concomittent rise in pressure within the head. (More detail can be found on this under the special topics menu). Some of the more common causes of hydrocephalus include aqueduct stenosis, normal pressure hydrocephalus, hydrocephalus secondary to haemorrhage or infection, benign intracranial hypertension and Arnold Chiari malformation.

Hydrocephalus can be investigated by a variety of means, including magnetic resonance imaging (MRI), to look at the ventricles within the head. Lumbar puncture, infusion pressure studies and intracranial pressure monitoring, are all investigations which measure, in slightly different ways, the fluid pressure within the brain.

Once the diagnosis has been confirmed, treatment may involve diverting the excess fluid from the brain to the abdomen by implanting a device called a ventriculo-peritoneal shunt. These consist of a silicone tube, the flow along which is controlled by a valve. There are many different varieties of these, some of which can have the valve's pressure setting externally adjusted by the treating consultant using an electromagnet. Some types of hydrocephalus may be amenable to treatment with a neuro endoscope to create a drainage passage for the fluid within the brain itself. More detail on hydrocephalus and ventriculo-peritoneal shunts can be found under the special topics menu.